SU1368740A1 - Automatic dust meter - Google Patents

Abstract

The invention relates to a technique of automatic continuous dust control in gas cleaning and dust removal systems and can be used in various industries to automatically control air flow in the study and control of the operation of dust collection plants and exhaust ventilation systems. The purpose of the invention is to improve the measurement accuracy when changing the mode of operation. An additional metering system in the gas duct is introduced into the dust meter circuit via a pneumatic meter tube, a pressure sensor and a transducer. The signal arrives at the automatic control unit, where it is compared with the signal received from the sampling tube through the second pressure sensor and the second npe-i generator. The automatic control unit when changing the operation mode (i.e., the occurrence of the error signal) changes the speed of sampling and drawing of the filter belt. I il. (L with:

Description

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The invention relates to a technique for the automatic continuous monitoring of dust content in gas cleaning and dust removal systems and can be used in various areas of the process for the automatic control of air flow in the investigation and control of the operation of dust collecting installations and exhaust ventilation systems.

The purpose of the invention is to improve the accuracy of determining the amount of gas dust when changing the operating mode.

The drawing shows an automatic dust meter circuit.

The automatic dust meter contains a sampling tube 1 installed in the duct 2, a pipe 3 supplying the gas to be analyzed, a filter belt 4, a tape-driving mechanism 5 with a drive 6 that rewinds the filter belt 4, a radiation source 7 and an additional radiation source 8, a gas outlet 9 , a photo cell 10 and an additional photo cell 11. The photo cells are connected to a communication unit 12 with a dust collecting device (not shown). The pneumatic system also includes a booster 13 tons of gi, a pneumatic tube 14, a dynamic pressure sensor 15 and a transducer 16 (converting a non-electric pneumometric signal into an electric one), a second pressure sensor 17 and a second transducer 18 connected to the control unit 19. The control unit 19 consists of a series-connected amplifier, a signal comparison unit, a signal ratio measurement unit and a logarithm. The communication unit 12 with a dust collecting device consists of a series-connected second amplifier, a second signal comparison unit, a second signal ratio measurement unit and a second logarithmizer.

Automatic piesemer works as follows.

The investigated gas, which is boiled by 13 tons of gas, is taken out of the duct 2 by means of the sampling tube 1, enters the nozzle 3 for supplying the test gas, in which its speed is significantly reduced in order to ensure effective dust deposition from the dusty gas on the filter

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tape 4. Filtered test gas is removed through the nozzle 9 for evacuating the test gas of 13 t of a booster and is emitted into the atmosphere. The filter belt 4, driven by a tape-driving mechanism 5 with a drive 6, is exposed to the radiation source 6 in a pure state, before the port 3 supplying the test gas, and the source 9 after filtration, behind the port 3 of the test gas. Filter tape. 4, with a layer of settled dust, attenuates the light flux from source 7, which is perceived by the photocell 10, thereby reducing the electrical output of the photocell 10. The light flux from source 8, which is perceived by the photocell 11, is constant, as the filter tape 4 is illuminated in its purest form. Both signals with photocell 10 and 11 are sent to a communication unit with a dust collector, the output of which is used as an error signal to control the operation mode of the dust collector.

In parallel, the air velocity in the duct 2 and in the nose of the sampling tube 1 is measured and compared in order to observe the isokineticity of sampling the test gas (the air velocity in the duct 2 is equal and in the tip of the sampling tube 1) and the speed of the filter belt 4 is controlled. which depends on the amount of gas to be taken. This is accomplished with the help of a pneumometric tube 14 installed in the gas generator, 15 dynamic sensors 17 and 17

converters 16 and 8 and control unit 19 automatic dust meter.

If the condition of isokinetic sampling is observed, the automatic piezmer operates in a steady state. The control unit 19 for the automatic dust meter is disabled, since the error signal from the logarithm is absent. When the mode of operation changes, the velocity of the air in the duct 2 changes (increases or decreases) and is disturbed. equal speeds of air in the flue 2 and in the nozzle sampling

This change captures the dynamic pressure sensor 15, the signal from which through converter I6 enters control unit 19, where this signal, as well as the signal from dynamic pressure sensor 17 and converter 18, is amplified in amplifier 24, enters signal comparison unit from it to the measurement unit of the ratio of signals, and then to the logarithm, whose contacts are located in the electrical control circuits of the tape drive mechanism 5 and the booster 13 tons.

The output signal of the logarithm as the error signal is used to automatically control the operation of the dust meter, namely the tape drive mechanism 5 with drive 6 increases or decreases the speed of movement of the filter belt 4, and the booster I3 t increases or decreases the amount of gas taken from the flue 2. As. the velocities in the gas duct 2 and in the nose of the sampling tube 1 are equal, the control unit of the automatic dust meter is turned off (due to the absence of an error signal), and the dust meter work t in the steady state.

An increase or decrease in the speed of movement of the filter belt 4 is explained by the need to observe the operational indicator — the amount of gas that has passed through a unit area of the filter material, in order to eliminate the total flow; - The use of a filtering material with a layer of settled dust.

The advantage of the dust meter is the ability to automate the process of determining the amount of gas dustiness when changing the operating mode (changing the air flow) and automatic control of the operation of the dust collecting device.

Claims (1)

The invention of the automatic dust meter containing a sampling tube, pneumatic ten 15 2o 25 thirty 35 0 five 0 is scientifically connected through a gas inlet, a filter belt and a gas outlet pipe with a booster rod, as well as a tape drive mechanism with a drive, a radiation source optically connected to the photocell through a filter belt, and a control unit characterized in that Increase accuracy. measurements when changing the operating mode, the piezmere additionally contains a pneumometric tube, two dynamic pressure sensors, two transducers, an additional radiation source, an additional photocell and a communication unit with a dust collecting device, the pneumometric tube is connected via the first dynamic pressure sensor and the transducer to the control unit, A second dynamic pressure sensor is installed between the sampling tube and the gas inlet, a sampling tube through the second sensor, The dynamic pressure and the second transducer are connected to the control unit connected to the thrust generator and the drive of the tape drive mechanism, the additional radiation source is optically connected to the additional photo cell through a filter belt, both photo cells are connected to the communication unit with the device, the control unit is made in the form of serially connected first amplifier, first signal comparison unit, first signal ratio measurement unit, and first logarithmizer; The dust-collecting device is made in the form of a serially connected second amplifier, a second signal comparison unit, a second ratio measurement unit and a second logarithmometer, and an additional radiation source, gas supply pipe and radiation source are installed along the filter belt sequentially in the direction of its movement. °