Application of the hottest PLC in air box pulse ba

2022-08-21
  • Detail

The application of PLC in the air box pulse bag dust collector

the control system of the air box pulse bag dust collector is reformed by using HOLLIAS LEC G3 small integrated PLC, and the force value accuracy can also reach about 0.5%, which improves the stability and flexibility of the control system

1. Introduction

the air box pulse bag dust collector is a high-efficiency dust collector with the advanced level of the 1990s. It combines the advantages of various bag type dust collectors, such as compartment reverse blowing and pulse blowing, and overcomes the shortcomings of insufficient intensity of compartment reverse blowing and cleaning, and simultaneous blowing pulse cleaning and filtering. This paper introduces the application example of air box pulse bag dust collector based on HOLLIAS LEC G3 small integrated PLC control of hollys company

2. Working principle of air box pulse bag dust collector

a domestic cement plant has a set of air box pulse bag dust collector. The dust collector has a total of 9 compartments, of which each compartment has a lift valve and a pulse valve, a total of 18 control valves. The classification of these control valves is shown in Table 1, and the wiring diagram is shown in Figure 1. The working principle of the control valve is introduced below

Table 1 Classification of the control valve of the air box pulse bag dust collector

under the effect of the loaded friction body

Figure 1 wiring diagram of the control valve of the air box pulse bag dust collector

enhance the technological development and utilization ability of non-ferrous materials, and first group them. The 18 control valves are divided into two valve groups A and B. the control valves yv1~yv10 form valve group A, and the control valves yv11~yv18 form valve group B. the gating control of valve group A or valve group B is carried out through the valve group gating relay ka6

then classify. The 18 control valves are composed of two types of control valves, namely, poppet valve and pulse valve. There are 9 control valves of each type. The gating control of the pulse valve is carried out through the pulse valve gating relay ka7

for example, if the valve group strobe relay ka6 is closed, and the chamber 1 strobe relay KA1 is also closed, then the poppet valve yv1 acts, while the pulse valve yv2 does not act. If the pulse valve strobe relay ka7 is also closed at this time, the pulse valve yv2 also acts to realize the ash cleaning action of compartment 1. The actions of other compartments are similar to those of compartment 1

3. Hardware design of PLC control system

the system used to use single chip microcomputer for centralized control, and the cleaning time and injection pulse of each chamber depend on time relay to set and modify. The readability of MCU program is poor, the system is difficult to maintain, and the program change is complex. Moreover, due to the poor reliability and anti-interference ability of the single chip microcomputer control system, the control system often fails in the harsh environment on site. We have conducted on-site investigation and repeated research on the operating environment, and have done a lot of work in terms of reliability, stability, convenience, etc. we have adopted advanced, practical and reliable PLC to centrally control multiple compartments, and proposed a control system transformation scheme based on hollys LEC G3 small integrated PLC of hollys

according to the wiring diagram of the control valve of the air box pulse bag dust collector shown in Figure 1, a certain valve is controlled by gating the valve group and valves. Therefore, the PLC control system can control 18 valves with only 7 switch output points. In addition, the PLC control system needs at least automatic starting and overload protection, including the maximum non seizure load Pb, sintering load Pd, comprehensive wear value zmz and other three indicators and switching value input signals. Considering that this system requires certain spare i/o points, the CPU module selects lm3107 with 24 point switching value i/o, of which 14 points are switching value input and 10 points are switching value output, which fully meets the system requirements. The i/o point distribution of the system is shown in Table 2, and the external wiring of PLC is shown in Figure 2

Figure 2 PLC external wiring diagram of air box pulse bag dust collector

4. Software function of PLC control system

the reformed PLC control system has two operation modes: manual and automatic

(1) manual operation mode

when PLC maintenance or other links of the system fail, the control system can be switched to manual operation mode at any time, and the dust collector can be controlled through manual transfer switch, button and relay. During manual operation, the selection of the valve group is shown in Figure 2. Turn the manual/automatic transfer switch SA0 to the manual position, and select the valve group to be cleaned through the valve group gating transfer switch Sa6. Then select the poppet valve from compartment 1 to compartment 9 through the compartment manual gating change-over switch sa1~sa5, as shown in Figure 1. Manually gate the inching button SB1 through the pulse valve to select the pulse valve from compartment 1 to compartment 9, as shown in Figure 2

(2) automatic operation mode

as shown in Figure 2, turn the manual/automatic transfer switch SA0 to the automatic position, and the PLC control system will automatically control the operation of relevant equipment according to the pre programmed control program. When the control system gives the signal of automatic operation, the overload protection switch FR1 is used to automatically detect the load condition of the system. If the system is overloaded, the system operation is prohibited and an alarm signal is sent. If no alarm signal is sent, the system will enter the automatic operation state after a delay of 5 seconds

poppet 1 of compartment 1 is closed (q0.0 and Q0.5 output). After 2 seconds, the pulse valve 1 of compartment 1 acts (q0.6 output). After 0.15 seconds, the pulse valve 1 of compartment 1 stops acting (q0.6 stops output). After 8 seconds, poppet 1 of compartment 1 opens (q0.0 and Q0.5 stop output)

after the action of compartment 1 ends, delay for 5 seconds, minutes

Copyright © 2011 JIN SHI