SU1397804A1 - Method of measuring concentration and particle sizes of dust in a gas stream - Google Patents

Abstract

The invention relates to a measurement technique, in particular to methods for measuring the concentration and dispersion of dust particles in a gas stream. The goal is to increase accuracy and expand the range of measurements. In the method, the electrical signals of the piezoelectric conversion from the impacts of dust particles are amplified, filtered in a frequency band proportional to the concentration of dust particles, with a center frequency equal to the frequency of the mechanical resonance of the piezoelectric transformation. Amplitude detection and the formation of video pulses are made, which are then discriminated amplitude. Here, the bandwidth is controlled by the frequency-detected signal, the counting pulses. Then, counting pulses are formed, according to the number of which, over a given time interval, the particle parameters are judged. I il. with "(L

Description

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The invention is designed to measure technology, it is intended to determine the parameters of dust and gas flows and can be used in mining, metallurgical and other industrial areas.

The purpose of the invention is to improve the measurement accuracy and rag; a wider range of concentration of the measured particles,

The drawing shows a functional diagram of an apparatus for carrying out the method.

A device for implementing the method comprises a piezoelectric transducer 1, placed in front of the nozzle of the measuring chamber with a blower and connected to amplifier 2, connected in series with band-pass filter 3, amplitude detector of radio pulses, low-pass filter 5 and amplifier 6 of low-frequency video pulses. The output of the amplifier is connected to the input of the discriminator 7. From the output of the discriminator, the analyzed signal through the normalizer 8 counting pulses goes to the counter 9 pulses. The shaper 10 of the pulse of the counting time T, made in the form of a voltage pulse generator of adjustable duration T, is connected to the Start and Reset inputs of the pulse counter 9.

To the bit outputs of the counter 9 pulses, the inputs of the setting knob II of the allowable number of counts are connected. The outputs from the setting device 1 and the imaging unit 10 are connected to the inputs of the logic circuit 12, designed to turn off the dust and gas flow. The output of the normalizer 8 is additionally connected via a frequency detector 13 to the control input of the bandpass filter 3.

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The method is carried out as follows.

Initially, it is set to a predetermined level determined by the dispersion of dust particles, the threshold. Set the measurement time T, determined by, for example, quality / permeability, dust capacity, absence of defects) tested in a gas stream with a metered concentration and dispersion of dust particles of the dust filter and start the imager 10 time interval pulse

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C4tn, 4 tons. At the same time, signaling with fstmirodtr.ch 10, passing to the input of the logical oxeMf i 12, will provide such switching voB, at which the blower and drunk particles in the gas flow will start, accelerating and concentrating by the nozzle, will begin hitting the sensitive element of the piezoelectric transducer I. At the same time, the pulse counter 9 pulses are reset.

Radio pulses with interference from a piezoelectric transducer 1 are amplified by an amplifier 2, a filter is a band-pass filter 3 in a narrow band, which is tuned to the natural frequency of a sensitive element of a piezoelectric transducer 1, and then o6pa3 TOTCH radio pulses with a bell-shaped shape envelope, which are detected with a low-pass filter with the formation of bell-shaped video pulses, the amplitude of which is proportional to the impact force of the particles in the gas flow of the piezoelectric Electrical converter 1, the number of video pulses is equal to the number of dust particles hit and is proportional to their concentration in the gas stream. Next, in the ycnjai 6 video pulses, they are amplified, then amplitude analysis is performed according to 1 signal level in a given range in the amplitude discriminator 7, normalizing in amplitude and duration with the formation of counting pulses in the normalizer 8.

Claims (1)

The appropriate i-nopor amplitude discriminator 7 and the sum of the pulses N counted in the counter at time T T 2: n j determine the size and concentration of dust particles in the gas stream. The counting pulses are also directed to the frequency detector 13, where they are detected in frequency during the measurement process. The signal from the frequency detector 13 controls the bandwidth of the narrowband filter 3 through its controlled input, expanding it proportionally with a large number of pulses per unit of time and narrowing the band at small. This eliminates the possibility of fusion and, in part, the imposition of radio pulses from the impacts of particles produced by narrow filtering at continuous values of the particles being analyzed. Invention Formula The method of measuring the efficiency and dispersion of parts of the process: in a lawn stream, lock 1 ayushk; The fact that the electrical signals of the piezoelectric transform from the blows of particles of dust amplify the filter, the filter that discriminates amperely discriminator, form counting pulses, according to the number of which are given for a given interval ;; 1 of the belt is judged on the parameters of the chunks, about one year and the other - for the purpose of raising s. /but NICH T OF PURIFICATION OF RAS RES IR Ir “MP I LI L, i and Lpcnii, a member of tric t-rcc signals iibeio. ipKTpuMccKoro and pe oPjiri tone,: smallpox enhancement of the filter of the Pmmsts Chagpsp, prpportsio alngch to the iiien i of the radio set; fuck, with ueHTjV) -i-io; Often, the frequency equal to the frequency of the pt ifJHaHca piezoelectric effect of the system is 10, an amplitude detonation is performed and the formation of nilso-) {mpulsov, DISCR1GMINIRI T) at the same time 111II11IIOY Bands are often controlled by, 5 frequency-detected g-signals of counting PULSES. Filter A l