Automatic Brick making control system and automatic brick tunnel kiln firing system is researched and developed by Weida electrial and machinery manufacture Co.,LTD according to introduce Italy technology and combine domestic brick making production technology. It have been approved in hundreds brick factory in China, as its excellent energy saving performance, high capacity and high brick quality, Chinese government asked national promotion for the DCS system.

Brief introduction of working principle for automaic brick control system:

The key technology of brick making is have proper and accuracy material and coal batching ration, proper and accuracy water distribution and a proper and scientific firing curve include heating up, isaothermal process, stay warm and cooling. Conventional naked eyes observation for batching and firing temperature is limited by external factor and Individual feeling factors, computer observation is not limited by above factors, computer scientific observation is the foundation of automatic control, the standard automatic  brick making and firing process bring a steady high quality and high capacity,  and also significant energy saving performance.

The system includes 4 parts:

1. Coal and clay automatic distribution system: Through PLC control, electronic belt weigher measuring, the measure precision meet 98~99%.
2. Automatic water distribution system: Use PLC control system, through belt weigher measuring the real-time flow of clay powders, the water quantity is changed automatically according to powder quantity.
3. Brick tunnel kiln automatic firing system: The brick tunnel kiln automaitc firing system pass the parameters which collected by temperatures sensor, moisture sensor, pressure sensor to computer, through signal amplification, acquisition parameter and Data Processing, computer compare the real-time firing parameters with the set standard firing curve, sent the compared date to displayer, at the same time, according to the difference with standard firing curve, computer (1)change the frequency of fan, adjust fan rotation speed to control air quantity and pressure, realized firing temperature regulation. (2) is able to start up automatic outer coal adding or spray coal powder to increase temperature, make the real-time firing curve and kiln bottom temperature meet or close the set standard firing curve. Thus guarantee the brick quality, capacity and Maximum improve kiln thermal usage, realized energy saving.
4. Kiln car system control system: PLC control, automatic enter or exit kiln car, automatic open and closed kiln door.
5. Distribution Control System: Control and monitoring the complete clay brick production line by computer in Central control room.

main technical parameters:

1 Application Range: Tunnel kiln and tunnel dryer

2 Working environment: -10℃~60℃、IP54 water proof、dust proof、Anti sulfur dioxide；

3 Motor supply: 220±60VAC(high-pressure protection: 400VAC、insulation 3000VDC、lightning protection)

　　4 testing index：

A  Temperature testing range: 0~1200℃，testing precision：±1℃；

B  Pressure testing range: -250Pa~+250Pa, testing precision：±1℃；

C  Frequency testing range: 0~50Hz, testing precision：±1℃；

5 Basic configuration: 32routes thermal couple, 2routes 4~20mA input, 2routes 4~20mA input, 8routes switch output.

6 Have sensors automatic testing for temperature, pressure, moisture etc, have function of history record and date real-time display.

7 Have function of inquiry display of history record, history firing curve and history alarm.

8 It is able to automatic or manual set up drying and firing technical parameters.

9 It is able to inspect qualify bricks according to firing curve and firing temperature, through ring a bell to prompt pusher working.

10  It is able to regulating firing temperature automatically according to firing technology, real-time firing temperature and firing condition.

A  Fan will increase rotation speed when temperature over heating, or decrease rotation speed when temperature is lower.

B  When temperature is lower due to the inner coal is not enough, can automatic adding coal.

C  Have the function of over-firing or down-firing alarm and indicate decrease temperature or increase the temperature operation.

11 The frequency converters have the function of manual or auto control

　　12  Reliable index：

A  Trouble free working time: 360days

B  Thermal couple performance life: 3 years

    Warranty years: 1 year

C   Computer and its interface performance life: 5 years

    Warranty years: 1 year

    Computer software update is free.

Clay brick and clay tile automatic system:

Clay brick and clay tile automatic control system include material(coal) distribution system, water distribution system, tunnel dryer and tunnel kiln control system and another auto Automatic Check Equipment and automatic control equipments. All equipments in this system should coordination thus it can meet technical requirements.

1.       Material (coal) automatic distribution system

PLC is the control center of this system, per belt balance automatic weighting, its dynamic measure precision meet 98~99%, capacity meet 120ton/hour, system according to actual coal thermal set up distribution ration, uniformly feeding material, make the brick inner firing is steady. And make the kiln temperature is steady, firing is easy to control, save coals 5~10%, firing is faster, increase capacity around 10%, at the same time, it decrease the down firing brick and over firing brick quantity, fired brick color is the same, brick quality improve largely.

Coal (coal gauge or other inner firing fuel) according designed ration automatic pursuit clay (or flyash) quantity, more clay means more coal add, stop feeding clay means stop feeding coal. The distribution parameter can be changed online, make sure the distribution is uniformly. The system operation is simply and low bread down rate, no need people monitoring.

Function moulds (option)

（1）Crusher overloading protection, avoid crusher jam and not burning motor.

（2）Raw material workshop interlock One-touch controls, reduce operators.

（3）Automatic spread materials uniformly, increase the aging room usage.

2. Automatic water distribution system

PLC is the center of this system, through belt balance measuring the powder real-time flow, the adding water is changed according powder flow, when powder water content is changed, it need water distribution rate in the control cabinet. The system can solve the problem which adding water is not uniformly, thus the extruding moisture is steady, green brick cutting face is smooth, reduce brick making machine failure rate and maintenance cost, improve brick forming capacity around 5%-10%。

The system can add interlock system, through program make powder convey, mixing, sent to extruder after mixing automatic operation. All brick making machine start in turn and stop in turn; when failure happens during production, the user can stop all machinery by “stop” button, once failure solved, press “start” then all machinery resume working in turn. The system realized fully automatic operation of all machinery in workshop. Operation is simple and reduces labor working intensity, improve productivity and no artificial attendant.

The system through belt balance feedback the signal, it automatic adding water, one-touch stop and start the system.

Function moulds

（1）Forming workshop electricity saving system

（2）Brick extruder overloading protection system

（3）Forming workshop centralized control.

（4）Setting machine and drying car automatic control system

3.Tunnel kiln temperature and pressure control system

Use special high temperature thermal couple, micro pressure sensor, and moisture sensor to collect temperature signal, pressure and moisture signal overall the kiln, through PLC calculation and processing, per special software do below controls:

（1）Draw the real-time and history firing curve of tunnel kiln

（2）Alarm for unusual temperature and pressure condition

（3）Through frequency converter automatic regulating air

（4）Automatic control coal distribution

（5）Automatic Identification qualified brick, sound and light alarm indicate kiln car outside time.

（6）Record production parameters such as temperature, pressure etc.

Configuration: Big platform, coal adding machine, high temperature thermal couple, low temperate thermal couple, air pressure sensor, moisture sensor, smoke temperature detector.

 4. Brick tunnel kiln transportation control system

  The automatic system includes brick tunnel kiln car, kiln door, pusher, ferry car, stepping machine etc.

The main part of this system is PLC and computer, it realized remote control, kiln door, ferry car, pusher, stepping machine are controlled by system, it reduce labors and guarantee the kiln safe, reliable and efficient.

5. Brick tunnel kiln distribution Control System(DCS)

Use the advanced computer control system and Communication Network System and Siemens PLC, form a Distribution Control System. In the central control room, it is able to use central control computer to realized remote complete production line control and monitor include raw material distribution, raw material preparation, adding water aging, spread material on aging room, sent aging material to forming workshop, brick forming, brick setting to drying car, kiln enter and exit, temperature control. The complete production process from start, running, stop, working condition observation, failure alarm, working parameter record are all automatic, it reduce labor intensity and labor cost, maximum improve productivity and guarantee production line  working steady, safe and reliable.

I. Introduction of China NH3 SCR technology

NOx emissions form coal fired power plant account for 80% of total industrial nitrogen oxides emissions; it is the main source of NOx pollution in China, strength the management of NOx emission is imperative.

At present, SCR(Selective Catalytic Reduction) for denitrification of nitrogen oxides in smokes is the mainstream technology in the world. SCR use reduction function of NH3 to NOx, under the condition of temperate between 320~400℃, that catalyst reduction happens change NOx to N2 and water which have no impact to the environment . “Selective” means NH3 only select NOx for reducing reaction.

In 2010, Ministry of Environmental Protection of China issue 《Technology policy regarding to power plant nitrogen oxides treatment》， it explicitly point out the nitrogen oxides not only is the import stuff form to ozone, but also is the important reason from district fine particle pollution and dust haze. At the same time, nitrogen oxides have great risk to human health as the primary pollutant.

In Sept 21 2011, Ministry of Environmental Protection of China enacted 《Standard for atmospheric Pollutant Discharge of power plant》, the laws determine the emission concentration of nitrogen oxides is 100mg/m3, execution time since 2012 for new generating sets while since July 2014 for old generating sets. All Chinese power plants should follow the standards.

30 Nov 2011, National Development and Innovation Committee of China enacted 《The State adopts a comprehensive measure to control coal and electricity price, explicitly point out since 1 Dec 2011, implement policy of price markup 0.8 yuan to every KWH for those coal fired power plants which have installed and normal use the SCR denitrification system.

The “upgraded” National Emission Standard will be the powerful driving force to control emission of coal fired power plant and improve China air quality and control Acid Rain Pollution. Along with prevalent of Selective Catalytic Reduction (SCR) technology, domestic research and develop SCR catalyst emerged, catalyst is the key of SCR system, its design and select is depend on smoke condition and smoke composition. Three interacting factor to catalyst design is NOx removal rate, NH3 escape rates and catalyst volume. The mainly 3 type of catalyst board type, honeycomb type and corrugated board type.

At present, domestic famous universities and colleges (such as NANKAI University, Tsinghua University, Beijing University of Technology, Zhejiang university, Shandong University, Xi’an Jiaotong University, Nanjing University of Science and Technology, Taiyuan University of Science and Technology, Harbin Institute of Technology, Xiamen University, Fuzhou university, The Southwest Research & Design Institute of the Chemical Industry etc) are all cooperate manufacturers research and develop honeycomb catalyst.

At present, the main raw material of catalyst is Titanium Dioxide TiO and other additives, the specification usually is cross section 150mx150mm, long 1000mm~1500mm, honeycomb hole usually is square(hole size and quantity is various) , samples as below Chart 1,

Chart 1 SCR honeycomb denitrification catalyst

Chart 2  honeycomb denitrification catalyst working process↑

II.SCR honeycomb denitrification catalyst production technological process:

2.1. Production process brief description：

Honeycomb catalyst production mainly includes 10 steps:

1. Titanium Dioxide and minor ingredient selection (formula R&D)

2. High speed and uniformly mixing material

3. Use pre-extruder fully filters the wet materials.

4. Sent the filtered wet material to de-airing extruder for extrude forming

5. Automatic synchronized cutting machine is able to according to different length cutting the products

6. Use manipulator load the products to carton avoid its distortion.

7. Steam damping-drum drier

8. mesh-belt kiln

9. Fixed length cutting

10. Inspection and packing

2.2. Main production equipments：

Main equipments for producing above SCR honeycomb catalyst are R-19 intensive mixer, TCIW-2T box feeder, TCJ-250 pre-extruder, WDQ-150 automatic cutting machine, TCJ-310 powerful extruder, WDYD-150 manipulator etc, other corollary equipment are:2X-30 vacuum pump, SK-240PT water temperature control system etc.

At present, Xiangtan weida electrical and machinery manufacturer co., Ltd through introduce Japan, American and German technology, combined their design advantage and its many years experience in extruding industry, after years of effort successfully developed a series of honeycomb catalyst making machines such as horizontal high strength de-airing extruder, synchronized cutting machine, rewrite the history which only vertical hydraulic extruder can extrude honeycomb catalyst, improve productivity largely compare to vertical extruder is discontinuous production.

Xiangtan weida electrical and machinery manufacturer co., Ltd specialized in ceramic machinery design and manufacturer, have 30 years design and manufacture experience. At the same time, the company cooperates with domestic famous university and institute for technology discussion and exchange, joint research and development, its production technology is leading in the world.

2.3 .Machinery list and quotation of Yearly output 3000m3 SCR honeycomb catalyst

2.4 Main technical parameters of Yearly output 3000m3 SCR honeycomb catalyst

Raw material preparation chart：

Raw material batching flow description (Raw material take 5 kinds of powder for example : A、B、C、D、E; fluid based on 4 kinds: a、b、c、d  )

1.Powder batching：

a)Storage 5 kinds powders A、B、C、D、E to powder silo A、B、C、D、E respectively;

b)According to batching ration sent the powders 将A、B、C、D、E to dosing tank per screw feeding system.

c)Open pneumatic discharge valve of dosing tank, input proportioned powder to intensive mixer once.

d)Open “mixer”, make the powders mixing 5~10 min in dry condition (mixing time is able to setup according to technique).

2. Fluid batching ：

a)Storage 4 kinds powders A、B、C、D to powder silo A、B、C、D respectively

b)According to batching ration sent the fluid a、b、c、d to fluid mixer per flow controller.

c) Open fluid mixer to mix the fluid uniformly.

d)Open“fluid pump”, according to pre-set flow uniformly spray the mixed fluid to intensive mixer per fluid pipes, make the powders mixing 5~6 hours with powders (mixing time is able to setup according to technique).

e) Open discharge hole, sent the mixed material to next process.

III.SCR honeycomb denitrification catalyst machinery description:

1. CX-0.5T/H reverse osmosis +Mixed bed high-pure water equipment

2. Liquid conveyor system

2.1 Hold-up vessel and Dissolve vessel (6 pcs): Include deionizer water, ammonia water hold-up vessel.

2.2 metering pump (8 set):include deionizer water, ammonia water metering pump etc.

2.3 pneumatic ball valve (24pcs): include reversing solenoid valve, MONITORING SWITCH

2.4 Others: Pipe arrangement (according actual site arrangement)

3. D type vertical intensive mixer

▲vertical intensive mixer main technical parameters:

●  Effective volume: ф2080×610（2000L）

●  Main shaft rotation speed: 750RPM(Maximum) adjustable

●  Rotary speed: 8~9 RPM

●  Total power: 139KW

●  Mixing period: 960 (adjustable)

●  Overall size: 3700×2500×2640mm

●  Weight: around 7000kg

▲Main components introduction：

●  Material introduction: Machine frame is high quality Carbon Construction Steel Q235A and 20# steel, Overall welding structure, All parts in touch with raw materials are made of acidproof alkali stainless steel 316L.

●  Main purchased parts: Motor is domestic brand (Xiangtan)

Reducer: material harrower drive is SEW

Rotating plate drive is TX

● Electronic control introduction: Fully automatic control include material feeding, mixing, and discharge

●PLC adopt SIEMENS or Mitsubishi

T35-11No.4A Cooling Fan

Used for intensive mixer

Motor：YSF-7114-0.25KW（IP55）

air volume：3849m3/h

Wind pressure：88Pa

Rotating speed：1450r/min

The transmission medium of fan is microcorrosion acid saturated damp air, temperature is 95℃, Fan bearing adopt NSK, blade, shield and bearing block adopt stainless steel 304.

GD30K2-12No.5C

GD30K2-12No.5C ventilation fan

Used for intensive mixer

Motor：Y100L1-4-2.2KW

Air volume：8000m3/h

Wind pressure：200Pa

Rotating speed：1800r/min

The transmission medium of fan is microcorrosion acid saturated damp air, temperature is 95℃, Fan bearing adopt NSK, blade, shield and bearing block adopt stainless steel 304.

DF03-R

DF03-R cartridge-type dust collector

Air volume：Q=1500 m3/h

filter area:：30 m2（cartridge qty:3pcs）

cartridge size：Φ350×660 mm

Cartridge material: filter media is high quality PET + PTFE coating

Filter efficiency: 99.99%

Filter wind speed: V=0.833 m/min

Dust collector Emptying concentration: 20-50 mg/ m3

Cartridge temperature resistance: <100℃

Dust cleaning type: pulse cleaning

Computation of air compression (customer prepared): 0.3-0.5 m3/min

Air compression pressure: 0.45-0.5 Mpa

Discharge type: Φ150 mm electronic discharge valve (stainless steel 304)

Supporting centrifugal fan: 9-19 NO 4A

Air volume：1410-1704 m3/h

Wind pressure：3507-3253 Pa

Motor poser：3 KW

4. TCIW-2T Automatic box feeder

Main technical parameters:

▲Material：

● All parts in touch with raw materials are made of stainless steel 304

● Hopper adopts stainless steel 304 (4mm), effective volume is 1.5m3.

▲ Technical requirements

●Y 90S-4  1.1KW  1400r/min

Driving motor of belt conveyor: Y 90S-4  1.1KW  1400r/min

●  Reducer of belt conveyor: Cycloid reducer, NBWED 42

●  Driving motor of feeding part: Y 132S-4  5.5KW  1440r/min

●  Reducer of belt conveyor: Cycloid reducer, NBWY 27

●  Belt conveyor: PVC material

●  Electric control system: vertical type(include wiring between operation table to machine )

●  Overall size(L×W×H)：约3500×1360×2890mm

●  Power resource：380V  three phase  50HZ

5.TCJ-250 Pre-extruder

▲Technical requirement：

●  All parts in touch with raw materials are made of stainless steel 304

▲  Up part：

●  Driving motor: Y200L2-6  22KW  970r/min

●  Reducer: Cycloid reducer XWD9-35-22-6P

●  Frequency converter: INVT

●  Screw blade: Φ250mm  304 stainless steel

●  Material cylinder: inner wall adopt stainless steel 304

●  Rotating speed of extruding shaft: 25RPM (adjustable)

▲  Down part:

●  Driving motor: Y200L2-6  22KW  970r/min

●  Reducer: Cycloid reducer XWD9-35-22-6P

●  Frequency converter: INVT

●  Screw blade: Φ250mm, 304 stainless steel

●  Extruding shaft: 40Cr

●  Extruding cylinder: inner wall adopt stainless steel 304 with cooling water jacket.

●  Rotating speed: 25RPM

●  Extruding speed: 1.5~2.5T/H (adjustable)

●  Overall size(L×W×H): 6000×1130×2088 mm

●  Net weight: 6000kg

6. TCJ-310 high strength de-airing extruder

▲Technical requirements：

●All parts in touch with raw materials are made of stainless steel 304

▲Up part：

●  Driving motor: SEW, DFV225S4/V 37KW 1470r/min

●  Up shaft reducer: SEW, MC3PLSF05 1:55.7403

●  UP shaft screw blade: Φ180mm, stainless steel, inner shaft water cooling

●  Up material cylinder: inner wall adopt stainless steel with water cooling system

●   Rotation speed of up extruding shaft: 29.6RPM (adjustable)

●  Cutter: adopt stainless steel 304

▲  Down part:

●  Driving motor of down shat: SEW, DFV280S4/V 75KW 1480r/min

●  Reducer of down shaft: SEW, M3PSF60 1:86.5623

●  Main screw blade: Φ310,stainless steel 304,inner shaft water cooling

●  Supporting screw blade: Φ220 stainless steel, inner shaft water cooling

●  Main shaft material: 40Cr

●  Extruding cylinder: stainless steel with water cooling jacket

●  Temperature and pressure sensor on extruding end, they convert signal and feedback to control plate.

▲  De-airing room

●  Inner wall: stainless steel 304

●  Vacuum pump: >550 liter/min

●  Motor for de-airing room: 3Kw

●  When vacuum pump working, noise should less than 75dB(within 1M), vacuum pump capacity should make negative pressure in vacuum room meet -0.096MPa.

●  Reserve observation window on 4 sides of vacuum room

●  Control cabinet: vertical type (include wiring between cabinet with machine)

●  Cooling pipe: exposed part with thermal insulation jacket

●  Power supply: 380V three phase 50HZ

●  Over all size(L×W×H): 6650×1730×2200 mm

●  Net weight: 12000 Kg

7. WDQ-150 Auto cutting machine

8. WDPY-150 Manipulator

▲ The function of manipulator：

The manipulator is placed after automatic cutting machine and Conveying positioning system, its main function is load the honeycomb adobe to tray, the process include clamping, lift, translational motion, put down, take off, lift, translational motion and put down.

●  Frame: welding components

●  Motor power: YEJ-80M24 0.75KW 1405r/min

●  Reducer: RV63 1:25

●  Up and down guide rail and air cylinder

●  Clamp and open guide rail and air cylinder

●  Sponge plywood

●  Electrical control system

●  Max. grabbing weight: 30kg

●  Max. lifting distance: 100mm

●  Max. displacement distance:1500mm

●  Every meters of cycle time: 15s/time

●Overall size：2900×1800×2600mm

●Net weight：450 Kg

9. Automatic cutting machine（Finished product fixed length cutting）

▲Main technical parameters：

●Max cutting length：350mm        ●Max cutting height：240mm

●Cutting bed size：440×490mm       ●Blade length：2900mm

●Blade width：3-13mm

●Angle of Inclination of working  platform：Back and forth 10º

●Angle of Inclination of working  platform：Right and left 15º

●Main motor power：1HP

●Gear box motor power：1HP

●Gear box speed regulating：Total 4 gears: 30、50、80、130

●Welding capacity：3-13m/m

●Weight： 280Kg

●Overall size（LxWxH）：920×700×1720mm

Feasibility study report (Text Extract)

Chapter 3 Proposal design

I Proposed production scale and design

 The complete production line can according the market to produce glazed tile and split tile at the same time or produce single product alone. Proposal production scale is daily output 25,000 pcs glazed tile or 3000M² split brick, calculation based on normal production time 11 month, the annual output is 8,250,000 pcs glazed tile or 990,000M² split tile.

1 Proposal for glazed clay roofing tiles

Mainly produce 310X310mm glazed clay roofing tile considering produce 280X280, 200X200 and other specifications and accessories.

2 Proposal for split tiles

Mainly produce 240X240MM broom-finish outer tile, at the same time can produce 115X250 square brick, floor tile and 96X200 wooden grain brick. It also can produce 50X240, 52X240, 115X240 and other specification brick by change mould and cutting length.

II Product quality standards

Product quality takes current Chinese building material industry standard, clay roofing tile use JC708-1998《Sintering tile》as standard. Main parameters as below:

①．Water absorption: 《=12%

② . Anti-bending strength: Ridge tile less than 1020N, S tile less than 1600N

③ ．Thermal stability: 130±2℃-15±5℃ do not crack in three times

④ ．Anti-frozen:  -20±3℃-15-25℃ 15 time within 3 hours do not damaged

⑤ ．Allowed size difference

   Specification    Allow difference   Allowed distortion

     250≤B≤350       ± 4mm               ± 5mm

200≤B＜250       ± 3mm                ± 4mm

 Split tile take JC/T457-2002《Extruded ceramic—fine stoneware tile》as standard, main technical parameter as below:

①    Water absorption: not more than 6%.

②    Fast cooling and heating stability: No crack and explosion during the experiment.

③    Anti-freezing: No crack and glaze take off during freezing 20 times.

④    Bending strength: the average value is not less than 20MPa, single value is not less than 18MPa.

⑤    Wear resistance: Non glaze brick volume loss is not more than 400m2. Glaze brick need the two sides agreed.

⑥ Anti-chemical corrosion: a. Acid resistance: The mass losses will not more than 4% when corrosion been takes place for Non-glaze brick, glazed brick not less than degree B. b, Alkali resistance The mass losses will not more than 10% when corrosion been takes place for Non-glaze brick, glazed brick not less than degree B

III Production technology design

1. Production technology process

The material preparation of glazed clay tile and split tile are the same (the material formulas are not the same). Per inspection, the qualified material have been stock in raw material silo respectively, according to the formula weighting and batching the material, than use forklift sent to box feeder to put material uniformly into Lemon grinder, after crushing, the material powder will be sent to silo for stock, a belt conveyor will sent the raw material powder to double shaft mixer for mixing with water, then sent to a screen feeder for granulation, then stock into aging room.

Glaze clay roofing tiles production: After aging, the material will be sent to boxer feeder by forklift, the boxer feeder uniformly put the material into vacuum extruder for forming, after auto press machine press the tile, tiles will be load to drying frame automatically, after drying and auto glazing, it is fired in the tunnel kiln after double drying.

Split brick production: After aging, the material will be sent to boxer feeder by forklift, the boxer feeder uniformly put the material into vacuum extruder for forming,  tiles will be load to drying car manually, after drying, manually load the tile into kiln car, than fired in the tunnel kiln after double drying. The fired brick will be splitting by splitting machine automatically, than inspect for warehousing.

 （1）   Material preparation:

Weighting and batching→use forklift to 15m3 Box feeder(1 set) →belt conveyor→Lemon grinder(15T/h, 1 Set) →material bin(charging bucket 1~2) →belt conveyor→double shaft mixer(add water)(1 set) →belt conveyor→screen feeder→belt conveyor→Aging chamber(Chain type)(3 set)

（2）   Split tile forming technological process:

Aging room→Belt conveyor→5m3 box feeder→belt conveyor→de-airing extruder→turn plate tile cutting machine→drying car(manual) →tunnel drying kiln→manual unload drying car→manual load kiln car→second drying kiln→tunnel kiln→auto splitting machine→inspection and warehousing

（3）Clay roofing tiles production line

Aging room→Belt conveyor→5m3 box feeder→belt conveyor→de-airing extruder→tile cutting machine→tile press→auto load drying car→tunnel drying kiln→auto unload drying car→auto hang tile machine→auto glazing machine→manual load kiln car→second drying kiln→tunnel kiln→auto splitting machine→inspection and warehousing

2.Main production technological parameters：

According to customer local material condition laboratory test, determine main production technology parameters as below:

① Raw material granularity preparation: 40   mesh    for glazed clay roofing tile, 80 mesh for split tile

② Ageing period: 》=24h

③ Extruding moisture: 17-19%

④ Max. first drying temperature is 50-85℃, drying period is 24h, residual moisture<5%

 ⑤ Max. second drying temperature is 120-200℃, drying period is 8-10h, , residual moisture<0.5%

⑥ Max. firing temperature for clay roofing tile is 1050-1200℃, firing period is 17H

⑦ Max. firing temperature for clay roofing tile is 1170-1210℃, firing period is 21H

IV Material balance

1Tile body material：110T/day

1.1 Clay roofing tile calculation based on below parameters:

Daily clay consumption for roof tiles: 25000*0.0034/〔0.95*(1-5%)〕*1.15=108T

1.2 Split tile calculation based on below parameters:

Daily clay consumption for split tiles 3000*0.021/(0.94*0.9*0.95) *1.15=90T

According below calculation, design clay consumption is 78~90T, considering to design allowance, daily actual material preparation capacity should be 110T

2 Glaze: 1.7T/day

Split tile no need glaze, clay roofing tile size based on 310X310mm, glaze loss is 10%, design allowance is 15%, daily glaze consumption is 0.050*25000/0.9/0.85=1.7T

  2 Fuel: generator gas (heat value 1200Kcal) around 37000m3/day

According related factory date, our experience, test and calculation:

 25000m3*3000m2/2200m2=34000m3

Split tile: According related factory date, our experience, test and calculation, energy consumption for split tile is 13636 kcal/m2 or 13636/`8=757 kcal/kg, when capacity is 3000m2/day, coal gas consumption is around :

25000m3*3000m2/2200m2=34000m3

Clay roofing tile: According related factory date, our experience, test and calculation, energy consumption for split tile is 1786 kcal/pcs or 1786/8=558 kcal/kg, when capacity is 25,000pcs/day, coal gas consumption is around:

 5000*1786/1200=37208m3

From above calculation, we select gas furnace model ￠2.4mm or ￠2.6mm, daily coal consumption is 12~15T.

4. Water consumption 50T/day

As adopt dry powder production technology, the water consumption mainly is used for powder humidification, extruding moisture is around 20%, raw material process requirement is 110T, needed water is around: 110/0.8*0.2=27.5, water consumption for glaze is around 17*0.8=1.36T, besides water consumption for clean, cooling and staff daily consumption, the total daily water consumption will be not more than 50T.

Detail list show as below chart 1.

Chart 1 Material consumption chart

 V Machines selection

    Main equipments selection principle:

1. Raw material preparation machines selection

Daily raw material process requirement is 110T, working time is 2 shifts, each shift is 8 hours, supposed average effective working time is 80%, machine normal working time is 16*0.8=12.8h, so raw material process capacity is required 110/12.8=8.59T/h.

According to designed production technology, raw material need crush and grind by Raymond grinder firstly, the machine capacity is 8.59T/h, and material granule should pass 80 meshes. We suggest use 5R(5 grinding head, inner diameter of head is 1200mm) Raymond grinder.  Box feeder, storage bin, double shaft mixer, pug mill, de-airing extruder is selected according to raw material process capacity requirement, the details show as below chart 2.

2. Forming machine selection

When produce clay roofing tile, daily output 25000pcs, qualify rate based on 95, design allowance based on 10%, required forming capacity is: 25,000/（0.95*0.9）=29,000pcs/day

Core equipment of clay roofing tile machine use WYJ-100 fully automatic press, the capacity is 15pcs/min, daily working time is three shift 24 hours, supposed effective working time is 85%, thus a press daily capacity is 15*60*24*85%=18360pcs/set, it need 2 sets when capacity meet 29,000pcs, at the same time, it also need two sets of small box feeder, de-airing extruder, cutting machine.

When produce split tile, TCJ 350 de-airing extruder daily capacity is 1200m2, for meeting daily capacity 3000m2, the green split tile capacity should meet 3000/0.9=3300m2, thus it need 3 set de-airing extruders.

According to calculation and related experience, the machines selection as below chart 2.

3. Drying and firing kiln selection

（1）The first time dryer

Drying car design：

For save investment and easy operation, designed drying car of clay roofing tiles and split tiles are the same. Each drying car has 6 layers.

Length: The length of wet green tile is 260-270mm, designed based on 2900mm, 2900mm*6=1.74m

Width: The width of wet green tile is 37mm, designed based on 50mm, 20*50mm=1.1m.

Height: considering producing width 115mm split tile, wet green tile is 127mm, space between layers is 140mm, layer frame steel thickness is 30mm, thus effective length is 170*6=1020mm.

Designed diameter of drying car wheel is ￠200, bottom frame steel thickness is 50mm, axle is ￠30mm, thus total length of drying car is 1020+100+50+15=1185mm

According to above date, designed drying car specification is: 1.75(L) X1.1 (W) X1.2m (H)

Dryer design:

Height: according to drying car specification, designed dryer length is 1.25m

Width: 2 sets side by side, thus the designed width is 1.1*2+0.2=2.4m

Length: According to customer raw material condition, the split tile drying time is 24 hours, according deign experience, design length for each dryer is 60m, thus hours moving length is 60/24=2.5m/h, drying car enter speed is 2.5/1.75=1.428car/h, enter period interval is 60/1.428=42min, enter times is 24*60/42=34time/day, every dryer include drying car 68 sets, every kiln car capacity is 20.5m2, thus every dryer drying capacity is 68*20.5=1394m2/day,3300/1394=2.36, when produce split tile, dryer needed: 3300/1394=2.36, thus need 3 sets.

When produce clay roofing tile, every layer only can place 3 lines and 5 rows, total 6 layers, thus each kiln car can place clay roofing tile 72 pcs. When drying period is 17h, 60/17=2.52m/h, every dryer daily capacity is 24*3.52/1.75*2*97*72=6984pcs, for meeting daily output 25,000pcs, dryer need: (25000/0.95)/6984=3.76, thus need 4 sets.

Considering producing both of clay roofing tile and split, the final design is 4 sets.

Drying car quantity: inside dryer is 4*60*2/1.75=274 sets

Outside dryer is 76 sets, total is 350 sets.

（2）The second time dryer：

The inner width of the second time dryer is the same with tunnel kiln, according to design experience, designed length is 60m. At the same time, for guarantee thermal supply is enough, it required a coal gas hot stove with diameter 1.2m.

（3）Tunnel kiln design

Kiln effective inner width is 2.6m, effective inner height is 0.45m, kiln car specification is 2.6×2.5m, according production technology requirement, firing period is 14 hours, calculate kiln length as below:

When produce clay roofing tile, every kiln car can load 310X310 S shape tile in 6 lines and 6 rows, total 350pcs/car, take quality rate as 95% for calculation, kiln loading capacity should meet 25000/95%=26316pcs, 26316/360=73.1/24=3.04（car/h）or 24*60/73.1=19.73min/car, finished firing within 14 hours thus the total length is 14*60/19.73*2.5=106.4m,

When produce split tile (240X60X11), every car can load tiles in 55 rows, 8 lines, and 5 layers, total is 55*8*5/35=62.86m2/car.

For meet daily capacity 3300m2, it required 3300/62.86=52.4car/day, as 52.4*2.5/24=5.46m/h, firing period is 20 hours, thus the total length is 20*5.46=109.2m.

 The final kiln design is : LXWXH=110MX2.6MX0.5M

 Chart 2 Equipment list and quotation                       

 VI Size of personnel force：

People needed for split tile production is more than clay roofing tile when forming and inspection, the detail as below chart 3 and chart 4

Chart 3 size of personnel force for split tile production

Chart 4 size of personnel force for clay roofing tile production

VII Installed capacity

 Chapter Four Economic and Efficiency Analysis

I. Total investment computation

 II .Production cost analysis (USD: RMB=1:6.3)

According domestic condition and actual customer local condition,

1.Clay roofing tile production cost computation: （1.647Yuan/pcs ）

1)        Raw material cost: RMB 0.17+0.22=0.39 Yuan/pcs

Clay cost: Single S shape clay roof tile weight is 3.2kg, clay consumption is around 4.2kg, clay price is around RMB 40yuan/Ton, clay cost is 4.2*0.04=0.17yuan/pcs. Glaze cost: bright glaze is 5000~8000yuan/Ton, matte glaze is 1500~4000yuan/T, supposed average price is 4000yuan/T, every tile cost glaze is around 55g, 0.055*4=0.22yuan/pcs.

2)        Labor cost: 0.10Yuan/pcs

The production line is semi auto clay roofing tile production line, need 50 labors, according customer’ local condition, average salary is 1500 Yuan/month,  1500*30/(25000*30)=0.10 Yuan /pcs

3)        Fuel cost: 0.4 Yuan/pcs

From above material balance computation, 37280m3 coal gas can produce 25,000pcs, coal consumption is 12~15T, coal price based on 800Yuan/T, thus 800*15/25000=0.48Yuan

4)        Water consumption：0.003Yuan/pcs

Daily output 25,000pcs clay roof tile need clay around 100 tons, according to 20% proportion to add water is 20 tons, considering to other water consumption, the total water consumption for a clay roof tile plant will not exceed 50 tons/month, water price based on 1.5yuan/ton, the cost is 1500*1.5/(30*25000)=0.003yuan/pcs.

5)        Electricity consumption: 0.144Yuan/pcs

0.144yuan/pcsThe clay roofing tile production line installed capacity is around 600KW, daily electricity consumption is 6000Kwh, 6000/25000=0.24kwh，electricity price is 0.6RMB/degree, thus 0.24*0.6=0.144=0.144Yuan/pcs

6)        Maintenance：0.07 Yuan/pcs

According to the experience of related the same capacity tile factory, monthly maintenance charge is RMB 50,000Yuan, thus 5/2.5*30=0.07Yuan/pcs

7)        Management expenses: 0.11Yuan/pcs

The clay roofing tile production line installed capacity is around 600KW, daily electricity consumption is 6000Kwh, 6000/25000=0.24kwh，electricity price is 0.6RMB/degree, thus 0.24*0.6=0.144=0.144Yuan/pcs

8)        Depreciation expense: 0.14Yuan/pcs

Plant building investment is RMB5,450,000, depreciation time is supposed be 20 years, machinery and kiln investment is RMB 1,054,000, depreciation time is supposed be 10 years, residual value is supposed be 5%, thus （545*0.95/20+1054*0.95/10）/12/2.5/30=0.14Yuan/pcs

9)        Tax 0.21

According to local law, the turnover tax rate is 6%, the other tax is around 10% of turnover tax, the sales price is supposed be 3.2Yuan/pcs, thus 2.5*30*11*3.2 *0.06/825 *1.1=0.21Yuan/pcs

Yearly total tax: RMB 825*0.21=1,730,000

2. Split tile production cost calculation

1)        Raw material cost:2.8

Clay consumption is around 28kg/m2, material price is supposed be 100Yuan/t, material cost is 2.8Yuan/M2.

2)        1.90 Electricity consumption

Actual electricity when producing split tile is 3.8Kwh/m2, thus production cost is 3.8X0.5=1.90Yuan/m2

3)        4.0 Coal consumption

Take daily coal consumption is 15T for calculation, coal price is RMB 800Yuan, daily output split tile 3000m3, thus coal consumption is 800*15/3000=4.0Yuan/m2.

4)        2.0 Salary

Average monthly salary is 1500Yuan according customer local condition, total 80 staff, thus 1500×80/9000=1.4Yuan/m2

5)        0.03 Water consumption

Daily water consumption is 20T, the price is 2Yuan/T, thus 50*2=/3000=0.03Yuan

6)        1.80元/m2 Packing 1.80Yuan/m2

Used carton for packing, at present the packing expense is 1.2Yuan/m2.

7)        According customer’s actual condition, maintenance expense is 0.6Yuan/m2.

8)        Depreciation expense 1.17

Monthly depreciation expense is 105,000Yuan; monthly capacity is 90,000m2, thus 10.5/9=1.17Yuan/m2

9)        Management expense 0.89Yuan/m2

According the same capacity factory experience, management cost is 80,000Yuan/Month, 8/9=0.89Yuan/m2.

10)    Tax 1.98

According to local law, the turnover tax rate is 6%, the other tax is around 10% of turnover tax, the sales price is supposed be 30Yuan/m2, thus 3000*30*6%*1.1/3000=1.98Yuan/m2

  Yearly total tax: RMB 1.98*0.3*30*11=196,000Yuan

III Yearly production cost= yearly capacity*unit cost

Clay roof tiles: 1.647*8250000=13,587,800

Split tiles: 16.12*99=15,958,800

IV Yearly sale amount= yearly sales quantity*unit price

Mainly produce S310X310 clay roofing tiles, sales price is 3.2~3.5Yuan/pcs, split tile price is 30~35Yuan/m2.

Produce clay roofing tile: 3.2*8250000=26,400,000

Produce split tile: 30*990000=29,700,000.

V Yearly profit= Yearly sales amount-yearly production cost

Produce clay roofing tiles: 2640-1358.78=12,810,000Yuan

Produce split tile: 2970-1596=13,740,000Yuan

VI Rate of return on investment= Yearly profit/total investmentX100%

Produce clay roofing tiles：1281/1949.8*100%=657%

Produce split tile：1374/1949.8*100%=70.47%

VIII Investment recovery period=1/ Rate of return on investment

Produce clay roofing tiles：1/0.657=1.5 years

Produce split tile：1/0.7047=1.4 years

1 Preface

WEIDA cooperate a Shandong kiln company supplied a complete clay roofing tile production line for North Korean in 2007，this article mainly introduce and discuss its clay roofing tile machines, kiln, related production technology and tile formula.

2 Production technological process and main production equipments

2.1Production technological process:

Mainly process as below:

Raw material—-15m3 box feeder—- cage crusher—-double shaft mixer—- roller crusher—-double shaft mixer—- roller crusher—- disc screen feeder—- material aging—- forklift carry material—-5m3 box feeder—-de-airing extruder—-automatic tile cutting machine—- auto tile press—-auto loading car machine— -tunnel dryer—- auto glazing machine—-tunnel kiln

2.2 Main production equipments:

2.2.1 Cage crusher:

The model is LA-1000, big rotating cage diameter is 1000mm, machine motor power is 55Kw, rotation speed is 500rpm, capacity meet 8~10T/H.

Working principle: small and big two cages high speed countermotions, semi-hard and block raw material fall down into the cage and impact each other, the crushed material discharge from bottom outlet.

2.2.2 Double shaft mixer

The model is SJ240X80, screw blade diameter is 240mm, motor power is 22kw, rotation speed is 60RPM, capacity is 20~25T/H.

Double shaft mixer is mainly used for fully mixing the material, in this production line, it is installed behind of cage crusher and firstly roller crusher for material kneading, make the water and clay composition more uniformity.

2.2.3 Roller crusher

The model is GS80X60, roller diameter is 800mm. width is 600mm, total motor power is 52Kw, capacity is 20~35T/H.

Roller crusher is the key equipments of raw material preparation machines. Its working principle is two rollers high speed rotation face to face, material fall down into the clearance between two rollers, material is crushed along with high speed rotation of rollers.

2.2.4 Disc screen feeder

The model is WD1200, screen diameter is 1200mm, screen hole is 22~25mm, motor power is 30kw, capacity is 10~30T/H.

Disc screen feeder is manly used for high-strength knead material again, make the material composition and water more uniformly, improve its plasticity.

2.2.5 De-airing extruder

The model is TCJ350, structure use twin stage three shafts. Down main shaft screw diameter is 350mm, TCJ 350 de-airing extruder is available used for extruding split tile, glazed clay roofing tile, high temperature roller kiln. The machine de-airing ability is good, the vacuum degree keep with above -0.092 when production.

The maximum rotation speed of main shaft is 19.8RPM, circuit configure frequency converter enable it can regulating speed according to production requirement.

2.2.6Automatic tile cutting machine

The model is WDQ-2, working principle: extruded green tile move forward by carrier roller, carrier roller is installed on the trolley of cutting machine. There have damper plate in the front of carrier roller, when extruded green clay roofing tile reach damper position, it will push the trolley move forward. When trolley move forward to required position, the cutting wire will performance cutting, then damper open, the tile after cutting will move forward to fast speed conveyor, and then trolley and carrier roller will reset and waiting for next cutting signal. As the extruded tile fully keep pace with wire cutting, it realized synchronized cutting, cutting face is smooth and straightly, cutting accuracy is high.

2.2.7 Fully automatic tile press

The model is WYJ100-1, main motor power is 7.5kw, capacity is 15~17pcs/min, fully automatic tile press is the key equipments of clay roofing tile production line.

Fully automatic tile press mainly consist of machine body, pressing platform, six side rotating wheel, back and forth manipulator, suction system and other components. The up mould is installed on the pressing platform, and the down mould is installed on the six side rotating wheel respectively.

When working, the front manipulator sucks the green tile up and put down into one of the six side rotating wheel which is backward titling 60°，then six side  rotating wheel spinning 60° on axis, make the green tile is on horizontal position, now the up mould move downward for tile pressing, at the same time, the front manipulator sucks the next green tiles up and put down into one of the six side rotating wheel which is backward titling 60°，green tile after double pressurizing press, up mould move upward, rotating wheel continuous backward titling 60°and the green tile after press is sucks by back manipulator and put down into conveyor.

2.2.8 First tunnel drying kiln

First tunnel drying kilnFirst tunnel drying kilnhe upperaccording to production requirment.ean  have three channels, each channel length is 90m, width is 3M, and every channel have 2 orbits, total 6 orbits, every channel have inside kiln car 60 sets. Thermal resources is come from residual thermal of cooling section of tunnel kiln and waste smoke of smoke exhaust fan, use air blower dehumidifying and Negative pressure humidity discharging. Maximum adjusting temperature is 50-150℃, design drying period is 20~24 hours.

2.2.9 Auto glazing line

Auto glazing line is consisting of auto hang tile machine, auto glazing machine, tile conveyor and transmission device. Compare to manual glazing, auto glazing machine glazing is smoother, texture is better and productivity is higher.

Working principle: tiles are hang up on the tile conveyor in turn and move forward, when pass to glazing machine, glazing head according locating device spray glaze on the tiles, tiles continuous move forward and become dry gradually, when tiles reach to setting position, put the tiles on the kiln car manually.

2.2.9 Second drying kiln

Thermal resource is come from hot blast stove (diameter 1.2m), kiln width is 2.6m, and width is the same with tunnel kiln. It mainly used to double drying and pre-heating with the temperature on 150-180℃, after 8~10 hours drying, the moisture of green tile is below 1%. Thus can improve the temperature of tunnel kiln head to 200-250℃ and realize fast heating, avoid tile crack.

2.2.10 High temperature tunnel kiln

This tunnel kiln use generator gas as fuel, inner width is 2.6m, effective width is 0.65m, and total length is 126m: pre-heating section is 39m, firing section is 36m, and cooling section is 51m. Kiln has total 120 nozzles: pre-heating section have 12 pairs, firing section up and down rows had 48 pairs. Nozzles left and right sides separation, Kiln maximum design firing temperature is 1200℃, design firing period is 21 hours, daily output clay roofing tile 25,000pcs.

3. Raw material and formula

3.1 Tile material and formula

3.1.1 Tile material

Kaolin: come form north area of North Korean, appearance is gray, blocky and soft clay, plasticity is good, contain a lot of charcoal impurity, iron and titanium content is a little higher. It appear ash black after firing at 1200℃. It mainly used for improve green tile plasticity and avoid tiles crack when in the process of pressing and drying. According to North Korean people introduction, this kaolin were use for daily ceramic production since 15^th century, is the most famous clay mineral locally, and mineral reserves is large, but the distance between factory is 800Km thus need railway transportation. Considering to the rail freight capacity is nervous, North Korean side required use as less as it, even do not use it at all.

PAQIN clay: Come form a place called “PAQIN” Where the distance between with factory is 25Km, it have hundred years for clay roofing tile making, is traditional clay roofing tile material in North Korean. The material is blocky and soft clay, organic content is higher, and aluminum content is lower, plasticity is poor, the tiles single using this material is easy to crack when nature drying, it can not single forming to tiles.

Bao hill red clay: Come from farm where the distance between with factory is 20Km, appearance is red, it also is soft clay and have good calenderability, but plasticity is poor. It mainly used for improve calenderability of green clay roofing tile.

White Sea sand: come form west coast, mineral reserve is rich, and only 20Km distance between with factory, it is white quartz fine sand, granularity is 20 mesh. It mainly used for lower the clay roofing tile firing and drying shrinkage, reduces tile distortion.

Above 4 kinds clay material chemical composition as below:                                Chart 1

3.1.2 Tile body formula

After repeated analysis and experiment, we confirmed the last production tile body formula, it show as below:

Tile body formula（%）                                  Chart 2

3.2 Glaze material and formula 

Glaze material as below:

Lead transparent frit: Origin come formChina, chemical composition as chart 3. Using Lead frit is used for make glaze have good gloss when generate on lower temperature.

Potassium feldspar powder: Origin come form North Korean, granularity pass 120 mesh, white degree is good, it mainly worked as fluxing agent. At the same time, it can improve glaze hardness and other performance. The chemical composition is as chart 3.

Chinese kaolin: Origin isJiangsu province,China, it mainly used for improve suspension property, avoid glaze precipitation and increase glaze generation temperature width.

Calcite powder: Origin is from China, it is mainly used form composite fluxing agent, lower glaze high temperature viscosity and improves glaze gloss, usage too many is not suitable, otherwise it will cause crystallization devitrification.

Barium carbonates powder: Origin isChina. It is mainly used form composite fluxing agent with other fusing agent composition, lower the glaze maturing temperature and high temperature viscosity, improve glaze gloss.

Zinc oxide: Origin is China, it appears yellow in color, as high-strength flux of glaze, it can well lower glaze maturing temperature, high temperature viscosity and surface tension, improve glaze gloss degree and covering power. As it also is a crystallizing agent, glaze surface will be crystalline when tile drying is improper.

   After repeated test and try, confirmed below formula as chart 4:

Glaze material chemical composition                           Chart 3

Glaze formula                                              Chart 4

4. Mainly production technological parameters:

4.1 Raw material preparation and forming

a. Roller crusher clearance: First roller crushing clearance: 1.8-2mm

                      Secondary roller crushing clearance: 0.8-1.0mm

b. Tiles material aging period:  ≥24h

c. Extruding moisture of green tile: 18-19%

d. Extruder vacuum degree: ≤-0.090Mpa

e. Extruding pressure: ≥1.0-1.5Mpa

f. Auto tile press forming pressure: ≥100t

4.2 Glaze preparation and ：

a. Material: ball: water=1：1.5：0.8

b. Ball mill period: Charge amount 1.0T, ball mill time is 12 hours

c. Ball mill granularity fineness: passing 325 mesh

d: Glaze proportion: 1.70-1.75

e: Glazing weight: 85~95g(clay roofing tile size: 315X315)

4.3 Drying and firing

a. Clay roofing tile nature drying time: ≥24h

b. First drying kiln max. temperature is 45-50℃, drying period is 24 hours

c. Green tile moisture after first drying: 4~6%

d. The second drying kiln max. temperature is 180-200℃

e. Green tile moisture after second drying: ＜1%

.  f. Firing temperature: 17-20h

5. Clay roofing tile property

After mass production, according to TC709~1998《China building materials industry standard products sintering watts》inspect clay roofing tiles, the inspection result fully up to standard. The main inspection result as below:

  a. Water absorption: 6~8%

  b. Ridge tile bending failing load is 2800N, main tile bending strength is N.

  c. 130±2℃～－15±5℃, thermal exchange 3 times no crack happens.

  d. Frost resistance: －20±3℃～15-25℃, repeated freezes 31 hours 15 times no layering and disintegration happens.

6. Problem analysis and discussion

6.1 1 should pay more attention to raw material test on the early stage.

According to normal procedure, it should do project feasibility study firstly; the most important work of project feasibility study is raw material analysis and test. Due some reasons, North Korean side neither sent material for us test and invite our engineer inspect material on site, they simply suppose their local material (PAQIN) was suit for clay roofing tile producing and placing a large order on this material. Our engineer fined this material plasticity is not good and organic content is higher when arrives their factory, it impossible forming tiles singly by this material. We have to re-test and research material thus waste a lot of time.

6.12 Production technology design and machine selection

For saving investment, this clay roofing tile production line canceled Raymond grinder on original proposal, and cause a lot of problem and limitation to late works of production technological formula R&D. Our ceramic engineer deny the possibility of forming roofing tile singly by PAKIN, and find Kaolin produce in north have good plasticity, but this Kaolin have a lot of wooden organism, it will cause bubbles and black heart if can not crush the material below 1mm. Due to there is no other good plasticity materials, at last North Korean side have to grinding the material by ball mill then use sprayer for granulating. Besides, we found hard terracotta stone which is suite for clay roofing tile nearby their factory, due to there is no proper fine crushing material, we have to abandon using them.

When design a production line, it can not just simple save investment, should fully consider technological requirement based on raw material analysis and test, necessary equipment can not be canceled.

6.1.3 Kiln design should according to clay roofing tile specialty and raw material property 

Glazed clay roofing tile is seems a simple terracotta product, but it have special requirement for kilns. It can not reach perfect result by using other kiln’s design and construction indiscriminately. The kiln for this production line is supplied by a Shandong kiln company, the kiln design and construction have not consider the actual material condition, thus make great troubles on production line commissioning.

a. Kiln 3 area length proportion problems: Regarding clay roofing tile, the structure is simple but thickness is a little thicker(15~20mm) and due to is formed by de-airing extruder, green clay tile density is high, organism oxidation and carbonate not easy to decompose when firing, the condition will be more serious if organic content is high, thus must make sure it have enough time for oxygenolysis when produce clay roofing tile, it required longer pre-heating area and firing area accordingly.

For cooling area, as tile structure is simple, tie size is small, it also can realize fast and uniform cooling even thickness is thicker. And due to water absorption is a litter higher(《12%), glass phase is few so that tile is not easy crack, the cooling area can be shorter.

But the cooling area of this kiln is 51 M when total lengths is 126M, account around 40% of total length, it easily cause black heart and bubbles when firing. If can extend 10~15M for length of firing area and shorten the length of cooling area accordingly, the tile quality will be better.

   b, Kiln air curtain problem: The tunnel kiln head did not set kiln door but airlock air curtain, and set mixing air curtain on pre-heating area. We do not know the reasons, all air curtain thermal resource is use indoor room temperature air. We think this is a failure design, kiln head air curtain is used for stop cold air of outside kiln enter pre-heating area which is under negative pressure condition, use cold air as air resource means cold air enter kiln head and air curtain is unuseful. Besides, mixing air curtain use cold as air resource lower the kiln head temperature, after second drying, the green tile temperature is above 150 ℃, but it be cooling when enter kiln, it waste energy and lower the heating curve. We suggest the air resource should be changed to residual thermal air form cooling area. After this production line, WEIDA established its own kiln Dept for better serve customers.

Glaze formula                                              Chart 4

The production technological parameters is depend on the raw material,fuel,capacity condition etc. Here list a typical glazed clay roofing tile production technological parameters from a clay roofing tile plant in Shangdong,China.

I Raw material preparation:

1. Jaw crusher: feed granularity <150mm, give granularity <20mm.

2. Roller crusher: The first time crushing clearance 1.8-2mm

                             The second time crushing clearance 0.8-1mm

II Drying

Max.Temperature 60~75℃

Drying period>=40 hours

III Firing:

1. Max.Temperature:1025℃

2. Car-in speed: 20.2min/car

3. Firing period: 19.6 hours

4. Water absorption rate: 3.5-4%

IV Glazed production technology

1. Add water 800kg, grinding 10 hours, and granularity pass 325 mesh

2. Glaze viscometer: 730

3. Glaze water absorption rate: 35-40%

4. Glaze proportion: 1.64-1.66

How to distinguish between soft plastic, semi-hard plastic and hard plasticity de-airing extruder

According the extruding pressure, classify de-airing extruder as below on international basis:
(1) Soft plasticity de-airing extruder: actual extruding pressure is 0.4~1.8MPa
(2) Semi-hard plasticity de-airing extruder: actual extruding pressure 1.8~2.5MPa
(3) Hard plasticity de-airing extruder: actual extruding pressure exceeds 2.5MPa, Max.pressure meet 8.0MPa.
Above date is from Handle German.
According extruding moisture, classify de-airing extrude pressure as below:
(1) America
Classify de-airing extruder as hard plasticity and soft plasticity 2 kinds. Classify principle is according to extruding moisture and brick or tile firing method.
A. Soft plasticity de-airing extruder: extruding moisture is around 12~20%, the extruded green adobe do not have enough strength, they must drying then load to kiln car for firing.
B. Hard plasticity de-airing extruder: extruding moisture is around 12~20%, the extruded green adobe do have enough strength, they will not distortion when setting height with 2 meters, can directly load to kiln car for drying and firing.
(2) German
Classify de-airing extruder as hard plasticity, semi-hard plasticity and soft plasticity 3 kinds:
A. Soft plasticity de-airing extruder: extruding moisture is around 19~27%;actual extruding pressure is 0.4~1.8MPa; green tile strength is 2kg/c m3
B. Semi hard de-airing extruder: extruding moisture is around 15~20%;actual extruding pressure is 1.8~2.5MPa; green tile strength is 2~3kg/cm3
C. Hard plasticity de-airing extruder: extruding moisture is around 12~16%, actual extruding pressure is 2.5~4.5MPa; green tile strength exceed 3kg/cm3
(3) China
No strictly classification, I prompt:
A. Soft plasticity de-airing extruder: extruding moisture exceed 18% which is normal clay roofing tile, split tile, terracotta facade, ceramic plate extruding moisture.
B. Hard plasticity de-airing extruder: extruding moisture between 12%~16% which is normal clay bricks extruding moisture.In fact, almost all clay bric making machine process material with this moisture.

We have constructed a Hoffman kiln in Uganda this year, and now share the construction experience here. The brick production line capacity is 25,000,000pcs/year.

I. Foundation: construction must start from the deepest part and from bottom to top part. The earliest construction part is main flue. Foundation should constructed on the original ground (soil), it need remove the soil to original ground if had partially soft soil locally, once soft soil still available 2M under ground, it could use stone for pad to -0.69 than uniform processing, soil dry density not less than 1.5g/cm, kiln inner foundation should earth cutting 0.4m of soil surface layer then use 3:7 spodosol for tamp to -0.15, and then use fine dry soil powder fill the gap after roll paving dry bricks.

II. Kiln body masonry

1.Wall: All wall should keep mortar joint filled, slurry brickwork mortar joint usually is not less than 3mm, sand slurry brickwork mortar joint is usually not more than 7mm.

2. Sloping core: according to specified gradient in the drawing construction, and use #75 mortar masonry.

3. Interior buttress: sloping core and interior buttress should be specified bricking brickwork, and according to masonry requirement add masonry, buttress height up to flue base plane, is 2050mm

III. Arch masonry

1. Kiln inner arch should use high class brick (grade over #150) for masonry; it is best using shale bricks or gangue bricks. It must use shale bricks or refractory bricks for masonry if it was used to firing shale brick or gangue bricks future, because clay brick refractoriness can not meet shale brick firing temperature.

2. Before construct the arch, it needs battening nail cotton rope on the center arch, each layer construction must correction by cotton rope, make each layer bricks must parallel circle rays.

3. Arch closing bricks masonry based on 3/4, then using wooden hamper knock them down slowly.

4. Afther finished arch construction, Intensify its gap by inserting tiles, tile inserting should use wooden hamper knock it down.

5. After finished arch construction, it need fill soil for buttress and arch two sides, soil filling height up to 2M then disassemble the arch mould.

6. Kiln door arch support installation should after the kiln main arch mould support installation, kiln door arch should be closed to kiln main arch mould, construct the kiln door arch then main arch, main arch bricks should press onto the door arch bricks.

7. Filling soil should use a little dry fine soil but not too dry, the moisture should be controlled between 10~2%, compact the filling soil per 20 Kg.

IV. Expansion gap

Expansion gap is lock mouth type, in not allowed any sundries into gap, open side fill asbestos cord.

V. Duty room onto the kiln: Duty room door direction should toward to kiln length so that is convenient to watch the kiln upside condition. Duty room length: outdoor 2.2M, indoor can be

VI. Kiln brushing: after construction acceptance, use slurry fine brushing the inner kiln room, the slurry thickness is not more than 3mm, slurry made from sieving clay with saline. Saline ration is: water :salt =10:3, it also can use refractory coating spraying, each kiln room consumption is 90kg.

Article form Weida machinery

High class clay roof tile production costing (based on RMB, and all clay roof tile machine are support by Weida machinery)

1. Raw material cost: RMB 0.17+0.42=0.41 yuan/pcs

Clay cost: Single S shapeclay roof tile weight is 3.2kg, clay consumption is around 4.2kg, clay price is around RMB 40yuan/Ton, clay cost is 4.2*0.04=0.17yuan/pcs. Glaze cost: bright glaze is 5000~8000yuan/Ton, matte glaze is 1500~4000yuan/T, supposed average price is 4000yuan/T, every tile cost glaze is around 60g, 0.06*4=0.24yuan/pcs.

2. Labor cost: 0.08yuan/pcs

Take clay roof tile plant with capacity of 25,000pcs/day as example, need 30 labors, average salary 2000yuan/month,  2000*30/(25000*30)=0.08 yuan/pcs

3. Fuel cost: 0.4 yuan/pcs

Single piece clay roof tile energy consumption is 1800 kilocalorie, nature gas thermal value is around 8500 kilocalorie/m³, prices accounting based on 2.0yuan/m³, clay roof tile energy consumption calculate as below: 1800/8500X2.0=0.4yuan/m².

4. Water consumption：0.003yuan/pcs

Daily output 25,000pcs clay roof tile need clay around 100 tons, according to 20% proportion to add water is 20 tons, considering to other water consumption, the total water consumption for a clay roof tile plant will not exceed 50 tons/month, water price based on 1.5yuan/ton, the cost is 1500*1.5/(30*25000)=0.003yuan/pcs.

5. Electricity consumption: 0.204yuan/pcs

Take clay roof tile production line with capacity of 25,000pcs/day as example, installed capacity is 672kw (include spare clay roof tile machines), usual working clay roof tile machines power consumption is 10817Kwh, calculating based on correction factor 0.8, daily actual electricity consumption is 10729X0.8=8653Kwh, electricity price based on 0.6yuan/degree, single pieces clay roof tile cost is 0.34*0.6=0.204yuan/pcs.

6.Mainteance：0.07 yuan/pcs

According to related more 30 clay roof tile plants’ experience, average monthly maintenance cost is RMB 50,000yuan, 5/2.5*30=0.07/m²

Above directly production cost (not include depreciation, tax. Management cost ) of single pieces clay roof tile is 0.41+0.08+0.4+0.003+0.204+0.07=1.167yuan.

http://www.tilemachinery.com

This de-airing German handle extruder is used for terracotta facade panel production line; the price is finally contract price which is nearly 4 times higher than our terracotta facade panel extruder.

Ceramic honeycomb production line denitration introduction

Oxynitride is one of main atmospheric pollutant, the source mainly from power plant, traffic sector and industrial sector, according to the statistic, the oxynitirde emission from power plant account of 40% of total country emission.It bring a series of problem such as increasing serious of haze weather, acid rain and so on. It’s very urgent for power plant waste gas denitration at present,

The denitration technology mainly includes selective catalytic production (SCR), selective non catalytic reduction (SNCR) and SCR combine SNCR (SCR-SNCR). SCR characterized by high denitration efficiency, sophisticated technology and the most widely application area, it is the mainstay denitration technology now in the world. The core technology of SCR is catalyst carrier production, due to China oxynitride emission control is still at an early stage, the core equipment of catalyst carrier making is long term depend on import from developed countries. For breaking the monopoly of foreign technology, after one years of trial and modification, Xiangtan Weida Electrical and Machinery Manufacturer Co.,LTD have developed complete ceramic honeycomb catalyst carrier equipments based on the core equipment of large pressure 4 shaft ceramic honeycomb extruder on 2009, per filed operation in Shandong, Jiangsu ,Beijing, it have performance achieved aboard advanced equipments level. Now, almost all of Chinese ceramic honeycomb manufacturer use our machines.

 Technology process as below:

According formula batching Ti02 and other additives, then add water into R19 intensive mixer for stirring, after the primary stirring and mixing, use special pre-extruder for filter and extruding, Then put the extruded blank to TCJ310 powerful ceramic honeycomb vacuum extruder for continuous forming to the long green body, and the green body is cut by automatic cutting machine, then carried to dry car by manipulator, through Multi-channel high temperature dryer drying, it is sintered in mesh band low temperature electrical kiln. The process as below:

Batching→R19 intensive mixer high speed mixing→pre-extruding→forming→auto cutting→mechanical manipulator loading→mesh band tunnel kiln sintering

 SCR ceramic honeycomb laboratorial main equipment list:

Machine list of annual output 3000m³ ceramic honeycomb catalyst production line