SU801857A1 - Apparatus for automatic control of hot-gas wet-cleaning process - Google Patents

Description

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The invention relates to a process for wet cleaning of dusty hot gas can & be used in the building materials industry, chemical, metallurgical and other industries.

A device for automatically regulating a gas scrubbing process is known, comprising temperature sensors installed downstream of a humidifier and a gas scrubber and connected to a subtractor unit connected to a water supply valve 11.

The closest in technical essence to the invention is an automatic control device comprising a differential pressure sensor on a wet filter, a differential pressure regulator, a regulator of water supply and sludge discharge, valves on water supply pipes to the filter bunker and discharge of sludge from the filter with connected with them are actuators, a gate with an actuator, a sensor for the angle of rotation of the gate shaft, and a differential pressure sensor is connected to the input of a differential pressure controller, the output of which is connected ene with the actuating slide mechanism wet filter.

, and the sensor of rotation angle of the gate shaft. is connected to the input of the regulator of water supply and sludge discharge, the outputs of which are connected to actuators connected to valves on the water supply and sludge pipelines from filter 2.

The disadvantage of this device is that when cleaning gases containing particles of substances that, when combined with water, the firmly enclosing composition, the mechanism of rotation of the gate that regulates pressure drop on the filter, quickly deteriorates as a result of sedimentation and solidification on it particles.

In addition, during the purification of hot gases, in addition to hot trapping in the filter hopper, there is an intense heat exchange between gas and water. The gas temperature at the filter outlet will be determined by the temperature and amount of water supplied to the filter,

5 as well as the frequency of discharge of sludge. With a change in the gas temperature at the filter outlet, the mass production of the ventilation unit is changed, which puffs up the dusty hot gas through the wet filter and the pre-suction. it has technological units and, therefore, changes the aerodynamic mode of operation of these units. The pressure drop on the wet filter does not determine unambiguously the mass productivity of the ventilation unit; therefore, the known device does not provide the specified aerodynamic mode of the aggregates preceding the wet filter.

Finally, in the event of an emergency shutdown of the ventilation unit, the pressure drop across the wet filter is zero. In this case, the known device will continuously supply water to the filter hopper, which can lead to its overflow.

The aim of the invention is to improve the quality of purification of hot gases.

This goal is achieved by the fact that the device is additionally equipped with a temperature sensor and a pressure sensor at the filter output, and two nonlinear blocks, while the temperature sensor is connected to the first input of the water supply regulator to the filter hopper, to the second input of which at the outlet of the filter, and the differential pressure regulator is connected via a second non-linear unit to the sludge discharge valve.

The drawing is a schematic diagram of the device.

It contains a wet filter, divided by partition 1 into cams of dusty gas 2 and purified gas 3 and having a pipe 4 with a valve 5 for supplying water to the filter hopper and a pipe 6 with a sludge discharge valve 7. Differential pressure sensor 8 is connected via pressure differential controller 9 and a non-linear unit 10 with an actuator 11 of the sludge discharge valve. The gas outlet sensor 12 at the filter outlet is connected to the first inlet of the water supply regulator 13, to the second inlet of which, via the nonlinear unit 14, is connected the pressure sensor 15 at the outlet of the wet filter.

The output of the regulator 12 is connected to the actuator 16 of the valve 5. In addition, the device is equipped with a setting device 17 connected to the differential pressure controller 9, and a setting device 18 connected to the water supply regulator 13. The device operates as follows.

The hot dusty gas enters the wet filter in chamber 2. Particles of the solid phase, when passing the dusty gas through the water, are moistened and remain in the water, and then removed from the hopper through the discharge slurry pipe b.

in the initial position, the valve of the discharge of sludge 7 is closed, and through the valve 5

; Water enters the filter hopper in an amount necessary to maintain the desired gas temperature at the outlet of the wet filter. Temperature sensor 12 measures this temperature and outputs a signal proportional to it at the first input of the regulator 13 for feeding the Veda to the filter hopper. In regulator

13, the incoming signal is compared with the setting signal of the regulator 18 and, if there is a deviation from the reference, the regulator 13, acting on the actuator 16, changes the water supply to the filter hopper, thus stabilizing the gas temperature at the wet filter output.

The pressure drop across the wet filter is measured by the sensor 8 and the signal from its output is fed to the input of the differential pressure controller 9. In the controller 9, this signal is compared with the signal of the setting device 17 and, with a positive error value, the controller 9 opens the slurry discharge valve 7, acts on the actuator 11 through the closed contacts of the nonlinear unit 10, to compensate for the deviation thus generated. The opening speed of the valve 7 is proportional to the sum of the deviation of the pressure drop across the filter from the set point and the rate of change of this deviation. When the pressure drop across the filter drops below a predetermined error signal from the regulator 9, it enters the input of the nonlinear unit 10, which commands the actuator 11 to quickly close the valve 7. The deviation of the pressure drop across the filter from the setpoint is compensated for by the water entering the hopper through valve 5.

In case of emergency shutdown of the ventilation unit, the pressure at the outlet of the wet filter will be equal to atmospheric. At the same time, according to the signal of the pressure sensor 15, a nonlinear block

14 outputs to the second input of the regulator 13 a large signal and regulator 13, acting on the actuator 16, will stop the flow of water into the filter hopper.

The use of this device allows you to eliminate the effect of the wet filter on the aerodynamic regime of the preceding units, thereby improving their operating conditions, and also ensures reliable control of the process of wet cleaning of hot gases.

Claims (2)

1. USSR author's certificate 581975, cl. B 01 D 47 / 06.01.04.76. 2. USSR author's certificate 341508. cl. B 01 D 47/02, 17.04.70