RU151193U1 - INSTALLATION FOR TESTING METERS OF MASS CONCENTRATION OF DUST AND AIR FLOW SPEED - Google Patents

Abstract

Installation for checking measuring instruments of mass concentration of dust and air flow velocity, including a metal casing made in the form of a pipe, aerodynamically made up of individual elements hermetically connected to each other and equipped with a device for straightening the air flow with a removable cone-shaped element, a dispenser dust, an exhaust fan, a sampler, and in the housing there is a gateway for accommodating the studied measuring instruments, characterized in that the housing is connected to the dust extraction pipe by your installation.

Description

The utility model relates to the mining industry and can be used for verification and calibration of measuring instruments of mass concentration of dust and air velocity. The utility model can be used in various industries to control the metrological characteristics of measuring instruments for the mass concentration of dust and air velocity.

A well-known stand for the study of dust and explosion-proof properties of the executive bodies of mining machines (patent No. 1244345, application No. 3841989, IPC class E21F 5/00, declared January 11, 85, published July 15, 86 in bull. No. 26). A well-known stand for researching the dust and explosion-proof properties of the executive bodies of mining machines includes a chamber with a studied executive body and with a sample of destructible rock mass, a dust and methane-air mixture supply system. Inside the stand there is a wall imitating the chest of the face and having a recess for a sample of the rock mass, a channel with a methane-air mixture supply system. By means of an ejector fan dust is fed into the stand.

The disadvantage of the stand is that the stand has a narrowly targeted purpose.

In recent years, in our country and abroad, intensive searches have been conducted for new, more effective methods and means of ensuring explosion protection of mine workings that meet modern requirements and technical capabilities. One of the important points in this case is the issue of controlling the metrological characteristics of measuring instruments for the mass concentration of dust and air velocity.

Installation UPP-1 was adopted as a prototype (Scientific Communications Issue No. 327/2004, of the National Scientific Center for Mining - Institute of Mining named after A. A. Skochinsky, p. 44). A known installation contains a dust dispenser, viewing windows, a wind tunnel, a device for controlling the amount of air, a fan unit, micromanometers, a gateway.

A significant disadvantage of the known installation is that it does not automatically remove dust from the research area, and therefore an error is allowed when calculating the concentration of dust in the air stream.

The technical result of the proposed utility model is the maximum approximation of the conditions of the research to the conditions of the actual operation of the devices in the mine and improving the accuracy of measurements.

Installation for checking measuring instruments of mass concentration of dust and air flow velocity including a metal housing made in the form of a tube in aerodynamic design consisting of separate elements hermetically connected to each other and equipped with a device for straightening the air flow with a removable cone-shaped element, dust metering device, exhaust

a fan, a sampler, and in the case there is a gateway to accommodate the studied measuring instruments.

The difference is that the housing is connected by a nozzle to a dust collecting unit.

The essence of the utility model is illustrated in the drawing, where in FIG. shows a diagram of the proposed installation.

In the drawing, the metal casing is designated 1, the dust meter is shown 2, the exhaust fan is shown 3, the dust collector is 4 (connection to the metal casing by means of a pipe, connection not shown) located outside the central air stream. A device for straightening air 5 can work both in normal mode (without additional narrowing of the air flow), and with a removable element 7 in the form of a cone. For sampling dust, a sampler is used, which, with the help of a pipe (not shown), is connected to the housing and sampling of coal dust (inert dust) is performed. In the gateway 6 is placed stand with placed on it measuring devices (not shown). Devices are placed in the direction of a moving air stream.

Installation for calibration of measuring instruments of mass concentration of dust and air flow velocity is intended for testing, calibration and calibration of measuring instruments of mass concentration of dust and air velocity. Therefore, it is important to create conditions as close as possible to the actual operating conditions of the device. To create an air atmosphere containing a certain concentration of coal dust (inert dust), the case 1 is used in the form of a tube in an aerodynamic design. An aerodynamic tube is a technical device designed to simulate the effects of the medium on moving or stationary devices fixed in it. Fan 3 is used to pump air. Using fan 3 allows you to evenly distribute coal dust (inert dust) in the air stream, which brings the artificially created atmosphere inside the unit closer to the natural mine atmosphere. By adjusting the speed of rotation of the fan 3, the speed of air movement is regulated, the creation of different conditions of the mine atmosphere is simulated. Several measurements are made at different dust concentrations and air speeds. Air speed is adjustable in the range of 0-25 m / s.

Coal dust (inert dust) uniformly supplied by dispenser 2 is picked up by the air stream. Several test sessions are conducted. Coal dust (inert dust) of different dosages is supplied through batcher 2 to create different concentrations. Possible conditions and a possible concentration of coal dust (inert dust) are simulated during various types of mining operations inside the mine. Inside the housing 1, a dusty air mixture of a given concentration is formed. Therefore, this feature is significant and is in a causal relationship with the claimed technical result. The conditions for testing are close to normal: air temperature - from 5 to 45 ° C, relative humidity set from 20 to 95%, atmospheric pressure from 84 to 106.7 kPA. To verify and control the parameters of the air mixture, a laboratory thermometer (TL-4, GOST 28498), aneroid barometer (M98 TU 25-11-1316-76), an aspiration psychometer (MB-4M, GOST 6353-52), and laboratory scales VLA are used. -200 with a set of weights GOST 7328-82. Instruments intended for testing are placed through the gateway 6 on a stand inside the case (not shown) in the direction of air flow. At the same time, sampling is performed through a sampler (not shown). Sampling is performed at steady-state air movement, at two points (before and after the instrument under study). Samples are weighed and the amount of dust in mg in the air stream is determined by calculation. The readings of the instruments under study are compared with the calculated readings obtained in the study of coal dust samples (inert dust). The error is determined.

The air flow at a certain speed passes a circle inside the housing, the upper part of which (the device for straightening the flow 5) is narrowed, the lower part has a cone-shaped extension. The narrowing of the channel allows you to increase the pressure of the air flow and, consequently, the speed of movement. Additionally, to increase the air flow rate, a removable cone-shaped element 7 is provided. To remove coal dust (inert dust), the stand contains a dust collecting unit 4, which is connected by a pipe to a metal casing 1 above the fan (connection not shown). The increase in the speed of air flow in the direction of the dust collecting unit 4 allows the most efficient removal of dust from the research area. This feature allows you to adjust the purity of the research and reduce the error when dosing coal dust (inert dust) into the air flow inside the stand, to predict the creation of the atmosphere inside the stand with the specified parameters and, as a result, improves the accuracy of measurements. Therefore, the symptom is in a causal relationship with the claimed technical result. When operating the installation for calibrating dust mass concentration and air flow velocity meters, it was experimentally determined that the limits of the permissible relative error of the installation when measuring the mass concentration of dust in% ± 12, relative installation error when measuring air flow rate,% ± 2 × (1 / v + 5). When conducting research, the diameter range of dust particles is used from 0.01 to 150 microns.

When conducting research and analytical calculations, the regulatory requirements of GOST R 50760-95 “Gas and aerosol analyzers for monitoring atmospheric air are used. General requirements ”, GOST R 50820-95“ Gas-cleaning and dust-collecting equipment. Methods for determining the dust content of gas and dust streams ”, GOST 17.2.4.06-90“ Nature protection. Atmosphere. Methods for determining the speed and flow rate of dust and gas streams emanating from stationary sources of pollution. "

The proposed utility model is in demand and relevant for its intended use. A prototype utility model is made and tested at the enterprise. It is proved that the proposed installation for checking measuring instruments for mass concentration of dust and air velocity can be manufactured in industrial production and used for checking and calibrating measuring instruments for mass concentration of dust and air velocity.

Claims (1)

Installation for checking measuring instruments of mass concentration of dust and air flow velocity, including a metal casing made in the form of a pipe, aerodynamically made up of individual elements hermetically connected to each other and equipped with a device for straightening the air flow with a removable cone-shaped element, a dispenser dust, an exhaust fan, a sampler, and in the housing there is a gateway for accommodating the studied measuring instruments, characterized in that the housing is connected to the dust extraction pipe by your installation.

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