Composition and control method of LOGO! Control system for ceramic dust collector
In the ceramic dust collector control system, the pulse spraying method is online spraying (that is, spraying during filtering). The control methods are automatic control and manual control, of which automatic control is divided into time control and differential pressure control. When the dust collector reaches the backflushing time or pressure difference setting value, it will enter the backflushing working state, and the pulse solenoid valve will be quickly opened / closed one by one (pulse width 200-300MS, pulse interval 20-300S, spray cycle interval 15-120min ), Manual control is a single control of each pulse solenoid valve.
The automatic ash unloading control methods are divided into automatic control and manual control. The automatic control position is time control and ash height control (that is, the height measurement level of the material level meter is reached). The dust collector reaches the ash unloading setting time or ash hopper material level. When the alarm is triggered, the ash discharge valve is opened, the ash discharge valve is opened for 2-20min, the opening interval is 30-180min, and the tank wall vibrator is vibrated while being opened, and the manual control is single control of the ash discharge valve and vibrator.
In order to achieve the above requirements and meet the operational reliability, operability and automation of the ceramic dust collector control system, the control system design uses LOGO! As the main control unit control loop.
According to the requirements of the input and output points of the high-temperature ceramic dust collector, LOGO! 12 / 24RC + LOGO! DM 16 24 digital module + LOGO! AM 2 * 2 analog input module are selected, with a total of 16 digital inputs, 12 relay outputs, 4 analog inputs. DC24V voltage input signal, DC24V relay output, DC24 4-20mA analog input. The input signal is connected to the manual and automatic start-stop buttons and the alarm signal of the level gauge. The relay output is connected to the solenoid valve coil, ash discharge valve coil and vibrator line. The analog input is connected to the transmitter for monitoring the working status of the dust collector. Displayed on the LCD. The pulse width, interval, period interval and opening width and interval of the ash discharge valve can be modified in the LOGO! Control panel corresponding timer. The LOGO! LCD display and panel operation replace the S7-200 / S7-300 + touch screen, effectively reducing the cost of hardware and software editing. The system wiring and LOGO! Pulse injection control are automatic injection time automatic opening / injection pressure automatic opening (I1 / DM16 24I8) button closed, reaching the automatic injection set time or pressure difference (AM2I1 differential pressure signal) setting The fixed value, the LOGO! Controller starts to run according to the edited program. The pulse solenoid valve is quickly opened or closed one by one. The pulse width is 200-300MS. The pulse interval is 20-300S. The spray cycle interval is 15-120min. (I2) The timer in the button closing program is reset and the time-controlled injection stops.
The ash discharge control is that the ash discharge valve automatically opens (DM16 24I3) button is closed to reach the set time of automatic ash discharge or the material level input is closed (DM16 24I7). The LOGO! Controller starts to operate according to the edited program and the ash discharge valve opens It is 2-20min, and the opening interval is 30-180min. When the bin wall vibrator vibrates when it is opened, the timer in the closing process of the ash discharge valve automatic close (DM16 24I4) button is reset, and the time control injection stops.
Manual control for the system to set a single control for each valve and equipment, solenoid valve manual button 1 # -8 # (I3-DM16 24I2), ash discharge valve manual (DM16 24I5) button and vibrator manual (DM16 24I6) button, respectively Control solenoid valve 1 # -8 #, ash discharge valve and vibrator.
In the past, the automatic control system of high-temperature ceramic dust collectors used PLC combined touch screen control and pulse controller control. Although the PLC combination touch screen control is powerful, the cost increases accordingly. Although the pulse controller control is lower in cost, the system is smaller, the control points are fewer, and the functions are incomplete. Siemens' small PLC-LOGO! Control system continues the stability of Siemens S7-200S7-300, and the cost is equivalent to the control system of the same pulse controller. LOGO! 'S reliability and advancedness meet the requirements of high-temperature ceramic dust collector control systems.