Keywords: programmable controller, frequency converter, industrial washing machine
1, Overview
Hunan a washing equipment limited (former medical equipment factory) is specializing in the production and development of industrial washing equipment. We provide various specifications of automatic washing equipments for hospitals, chemicals, petrochemicals, hotels and guesthouses and various manufacturing enterprises. It has more than thirty kinds of washing products, such as semi/full-automatic centrifugal washing machines, semi-automatic horizontal drum washing machines, and full-automatic material crystallizing machines. The products are widely used in hospitals, hotels and large enterprises. In recent years, under the influence of household automatic washing machine vigorously promoted, large-scale industrial washing equipment also from the original relay control mode period gradually into the fully automatic control era.
2, process
The entire washing process is divided into four parts: water inlet, washing, water discharge, dehydration, the system starts from the water inlet to the end of the dehydration link **** cycle three times.
A. The system runs three cycles: the first cycle of the drum feed water to the water level in the beginning of washing; the second and third drum feed water to the high water level in the beginning of washing.
B. The washing mode is divided into light washing, standard washing, strong washing (according to the forward rotation, stop, reverse rotation, stop the four-step action cycle until the washing time arrives)
C. In the 20-80HZ frequency dehydration session if the drum appears to run vibration, then the inverter stops the output to the drum stops and then re-dewatering from 20HZ.
3, control requirements and functions
A. The washing equipment should be equipped with delayed stop water inlet function (i.e., the washing water into the water level or high water level when the washing water begins to wash but does not shut down the inlet valve until the delay time to stop the water inlet)
B. The system has a stop and emergency stop function (i.e., the system is running in the press the stop button will terminate all operations, and then start from the first start when the system starts again. The system has a stop and emergency stop function. When the emergency stop button is pressed, the system pauses, and when the emergency stop is reset, the system continues to run from the emergency point)
C. The start, stop, emergency stop and parameter setting of the washing machine are all accomplished by the human-machine interface.
D. The system uses the simple PLC function of frequency converter to complete the multi-segment speed profile of the washing machine dewatering section (the first section 20HZ / 20 seconds; the second section 50HZ/15 seconds; the third section 80HZ/15 seconds; the fourth section 100HZ/10 seconds; the fifth section 130HZ/10 seconds)
E. The frequency of washing is accelerated/decelerated at a rate of 2HZ/second, and the frequency of spinning is accelerated at a rate of 0.5HZ/second. frequency acceleration rate 0.5HZ/sec, deceleration rate 1.5HZ/sec.
F. If the mechanical vibration during dehydration is greater than the designed vibration, the system should stop the output of frequency converter until the drum stops, and then start dehydration from the first stage again (the signal is provided by the vibration switch).
G. Simple PLC in the frequency converter from one to five stages of the operating frequency and operating time set by the programmable controller through the communication method.
4, the system control principle
The system consists of programmable controllers, frequency converters, touch screen and other control elements, programmable controllers to complete the entire system logic control, the operation of the relevant parameters to transmit and read and write, the equipment running status display function. Inverter and programmable controller using free port communication protocol communication to complete the equipment start / stop, simple PLC program execution and other related operating parameters of the transmission. PLC and touch screen communication to achieve man-machine dialogue, to complete the relevant parameter settings, start / stop operation and status display.