A control method for maintaining a constant liquid level in the filtration state of a v-type filter

Abstract

The invention discloses a control method for keeping the constant liquid level of a V-shaped filter in a filtration state and belongs to the field of V-shaped filters and automatic control in the wastewater treatment industry. By utilizing a PLC control system and combining with a pneumatic regulating butterfly valve installed on each V-shaped filter cell water outlet channel inlet pipe in a fieldand used for regulating outlet water flow of the V-shaped filter, an ultrasonic remote-transmission liquid level meter installed in each V-shaped filter cell and a lift pump set outlet water main pipe remote flow meter of a lift pump room installed in front of the V-shaped filter, control of constant liquid level keeping of the V-shaped filter in the filtration state is achieved to solve the problems that in the prior art, due to the fact that the liquid level fluctuation change of the filter is slow and the control has larger hysteresis, the liquid level of the filter fluctuates in a set large liquid level range, water channel overflow is caused, meanwhile continuous control causes frequent actions of the valve, and the service life of the valve is shortened, so that the constant liquidlevel and constant filter speed of the V-shaped filter are kept, and a filter effect is better. The control method has very good economic and social benefits and is high in practicability.

Description

technical field [0001] The invention belongs to the field of V-shaped filter and automatic control in the sewage treatment industry, and in particular relates to a control method for maintaining a constant liquid level in the filtering state of the V-shaped filter. Background technique [0002] The V-type filter is an important link in the water purification process of the sewage treatment plant. The V-type filter adopts the control process of constant water level and constant filtration rate. If the operating water level of the filter is too high, it will cause the submerged flow state of the inlet weir to form a yam, which will lead to the collusion of the water surface between adjacent filters, so that the independent filter automatic control devices will detect the change in the operating water level of the filter. When encountering interference, it is difficult to achieve self-control adjustment; too low operating water level, which cannot meet the requirements of water...

AI Technical Summary

Problems solved by technology

Due to the slow change of the liquid level fluctuation, the control has a large hysteresis, and the PID control algorithm often has overshoot and adjustment dead zone, which makes the filter liquid level fluctuate in a wide range above and below the set liquid level, which will easily lead to the overflow of the outlet channel. At the same time, the PID Continuous control leads to frequent action of the valve, which greatly shortens the service life of the valve

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