Control of the hottest single PLC multi-stage insu

2022-08-08
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Control of single PLC multi-stage insulation double seat annealing furnace

equipment description

annealing is to heat steel or various metal mechanical parts to an appropriate temperature, keep them warm for a period of time, and then slowly cool them. It can obtain a heat treatment process that is developed and utilized around some environmental protection product lines and is organized in a near equilibrium state. Its purpose is to refine the structure, reduce the hardness, improve the machining performance and remove the internal stress. In the mechanical manufacturing industry, annealing is usually used as the preparatory heat treatment process in the workpiece manufacturing process

strong convection electric heating bell type bright annealing and Bluing furnace is mainly applicable to dozens of materials such as brass strip, bronze strip, special-shaped copper strip, red copper strip, various precision copper tubes, coin making materials, precision strip, composite strip, soft magnetic and hard magnetic alloys, copper alloy wire rod, standard parts materials, stainless steel strip, etc. The maximum charging diameter of a single bell jar furnace is 3.2m, the maximum charging height is 4m, and the maximum charging capacity is 80t. Considering that some small metal processing enterprises have no gas source and no coal source, the furnace adopts the heating method of resistance strip. Compared with the gas bell type annealing furnace, the operation cost is relatively high and the production cycle is relatively long. However, the equipment has the advantages of simple configuration, reliable operation and convenient maintenance. The temperature at each stage of the annealing process can be set to meet the annealing needs of various metals

the electric heating bell type annealing furnace adopts a single set of control system to independently control the double furnace seat heating annealing furnace. The furnace body itself uses new light energy-saving materials, with reasonable structural design and good insulation effect. When the temperature of the resistance band reaches 1000 ℃, the shell of the heating cover is only the ambient temperature plus 40 ℃. Nitrogen and hydrogen are used as the protective gas in the material chamber, so that the annealed material has no oxidation and decarburization under the high-temperature annealing state. The vacuum pumping system saves a lot of protective gas and power consumption. The control system adopts a single set of Siemens s series PLC to fully automatically control the temperature rise, insulation and cooling process of the two sets of heating furnaces. Thermocouples with high sensitivity are used to collect the temperature of the outer cover and the inner cover of the furnace body respectively, and the working state and heating frequency of the heater are adjusted according to the temperature value PID set during the temperature rise and insulation, so as to ensure that the insulation temperature is specific to the key interior parts such as seats, instrument panels (interior trim panels), paint upholstery parts The carpet damping pad, clothes rack, etc. are constant, and are equipped with an 8-inch touch screen, which can vividly and vividly control and manage the heating, insulation and cooling processes of each furnace base, providing a reliable guarantee for users to produce qualified products

equipment features

1. A single Siemens s PLC is used to independently control the electric heating bell type annealing furnace with two furnace seats for heating, insulation and cooling at the same time. The controller is small in size and cheap in price. The price of the whole controller is about 8000 yuan, with high control accuracy

2. The whole set of equipment adopts all-round automatic control. As long as the user sets the temperature and holding time of each stage through the touch screen according to the process requirements, and turns on the heating switch, the heater, hot air blower, cooling fan, etc. will automatically operate according to the program

3. With the three-stage insulation control technology, the user can set three different temperatures according to the process requirements, so that the annealed material can be insulated for a predetermined time under different temperatures and different protective atmospheres

4. High sensitivity thermocouples are used to collect the temperature of the outer and inner covers of the furnace body, and the working state and heating frequency of the heater are adjusted by PID according to the temperature values set during temperature rise and insulation. The insulation precision is high and the effect is good, and the error between the actual temperature of the inner cover and the set temperature is ± ℃

5. The set temperature node and equipment fault in the whole annealing process will prompt the user in the form of buzzer alarm and provide relevant alarm information

6. It has thorough interlock protection. When the annealing furnace needs to be vacuumized, the electronic universal testing machine must stop all heaters and ventilation equipment before vacuumizing. The gas in the inner hood does not reach the standard pressure, so it is impossible to restart the heaters and ventilation equipment

7. The resistance belt heater is divided into contactor control and solid-state relay control, which not only ensures the rapid rise of temperature during heating, but also avoids frequent temperature fluctuations during insulation

III. annealing furnace multi-stage insulation control setting curve

in the annealing furnace multi-stage insulation control setting curve, it is divided into outer cover temperature curve and inner cover temperature curve. In addition to setting the temperature and holding time of the three-stage insulation, it is necessary to set the secondary vacuum pumping, nitrogen filling, hydrogen filling, hydrogen closing, steam filling and furnace exit temperatures. When the inner cover temperature reaches the corresponding temperature, The system sends an alarm to prompt the user to perform corresponding operations

IV. main operation screen of two seat annealing furnace

v. control system configuration

1 Siemens s series cpu226, DC24V power supply, 24di/16do

2. Siemens s series EM231, 4-channel TC temperature input

3. Siemens s series em232, 2-channel voltage transmission impulse testing machine is playing a more and more important role

4. Siemens s series em222, 8Do relay output

5. 8-inch touch screen, th865-m. (end)

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