Technology Discussion

September 26, 2012

Automatic control system for clay brick plant(DCS)

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

brick material batching system 2

brick material batching system 3

 

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

clay brick production water adding systemPLC 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

 

clay brick production line auto control cabinetkiln auto running 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)

kiln auto running control system 2Use 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.

 

Clay brick