SU1681273A1 - Method for checking gas composition of mine atmosphere - Google Patents

Abstract

The invention relates to the development of coal deposits by underground methods and can be used when working in mines with constant control of the composition of the atmosphere in mining. A constant air pressure is maintained at the entrance to the gas analyzer unit when switching from one channel to another, as a result of which there are no transition processes in the gas path of the analyzers. The pressure is achieved by aligning the aerodynamic characteristics of the sampling lines with each other. Thus, the flow rate of the air mixture in each line is the same, as well as the pressure surges when switching channels. 1 il.

Description

The invention relates to the analytical control of the gas composition, for example, using thermochemical sensors and can be used in coal mines and mines to analyze the composition of air in mines, bunkers and other structures and premises in mining and other folk industries. .

The purpose of the invention is to increase the reliability and reliability of monitoring the gas composition of the mine atmosphere.

The drawing shows a block diagram of a system for collecting, transporting and analyzing gas pipes.

The method consists in continuous remote sampling and transportation to the central point of mine air samples through the air sampling channels in parallel with gas analytical and

Bypassed promptings. According to a predetermined program, the gas-analyzer booster selects, transports and submits the gas sample for analysis at each current time from one control point, and the bypass one selects and transports gas samples from the remaining control points, ensuring that all control points are polled during the cycle. The nominal operating vacuum of the boosters is established, based on

and u 4 a 1trmakschu2

Ib - g1g. - jVonr,

OTR

where Nb is the vacuum created by the bypass booster, kg / m2;

Nga - the vacuum created by the gas analytic booster, kg / m2;

OS-coefficient of aerodynamic drag of the tube, kg cm / m4

About 00

Yu

Xi

with

I is the length of the tube sampling from the control point furthest from the central point, m;

dip - internal diameter of this tube, m;

Vonr - the gas flow rate in the tube corresponding to the optimal sample flow rate through the gas analyzer unit, m / s, the volumetric flow rate in each channel is established, alternately connected with fully open tube rotameters to the gas analysis pump, the channel with the minimum volumetric air flow is established and the corresponding minimum flow in all other channels, alternately connecting them to the gas analysis pump.

The system with which the method is carried out consists of intake devices 1, 2, 3. air sampling lines 4, 5, 6, the number of which corresponds to the number of control points, individual air chokes 7.8 and 9 with rotameters and three-way electropneumatic valves 10, 11 and 12, one for each line, a bypass collector 13 and a gas analysis manifold 14, vacuum gauges 15 and 16, an air throttle 17 with a rotameter bypass booster 18, a throttle 19 for a gas analytic booster 20, a unit 21 of gas analyzers and a switch 22 controlling the operation oh the whole system. When the unit is operated at 30 control points, the air through 29 lines enters through the intake device (only two -1, 2 are shown in the drawing), which are metal tips with dust filters, then passes through the air bleed lines, for example, through polyethylene air tubes laid in the mine workings, to the surface of the mine, where it passes through air throttles 7 and 8, by means of which the volume flow of air is controlled, and through pneumatic valves 10 and 11, intended for switching air fluxes enters the bypass manifold, which is a bulk storage tank 13. Then, through the bypass choke 17 stimulus by which controlled flow air mixture is brought to bypass stimulus, which is of SEB Vakkumnye pump creates the necessary system irritation. After passing the bypass drive, the air is vented to the atmosphere. On the thirtieth line from the intake device 3, the air is also transported through a polyethylene pneumatic bushing, passes through the choke 9 and enters the pneumatic valve 12, then into the collector 14, from which it passes through the throttle 19 of the gas analytic booster, and with the help of the booster 20, which is a vacuum pump performance (in

in this case, equal to 1/30 of the performance of the bypass booster, enters the gas analyzer unit 21, where it is analyzed, and then removed to the atmosphere. Then after a time interval (5 min)

The 29th line pneumatic canal switches to a gas analyzer booster, and air is already coming from this channel for analysis. And the 30th pneumatic valve switches to the bypass booster (pump). The sequential switching of the valves is carried out with the help of an electronic switch 22, and the control of the vacuum of the air in the system is carried out with vacuum gauges.

To eliminate transients in gas analyzers when switching channels, it is necessary to maintain a constant pressure at the inlet to the gas analyzer unit, which is achieved by equalizing the aerodynamic characteristics of the channels.

To do this, each of them is connected with fully open throttles x 7, 8 and 9 rotameters to a gas analyzer booster 20. Having determined the channel number with maximum resistance and air flow through it,

connect the subsequent channels to the gas analyzer. Changing the resistance of air chokes, select the air flow in each channel, equal to the air flow in the channel with maximum resistance.

Claims (1)

Claim Method The method of controlling the gas composition of a miner atmosphere, consisting in continuous remote sampling, transporting and analyzing at the central point of mine air samples through the air sampling channels in parallel with the gas analytical and bypass drivers, the first of which A given program selects, transports, and delivers a gas sample for analysis at each current time point from one control point, and the second one selects and transports gas samples from the rest of the control points, ensuring that all control points are polled during the cycle. in order to increase the reliability and reliability of monitoring the gas composition of the mine atmosphere, the nominal operating vacuum of the boosters is established, based on Н6 ° Нга-4а1тРмаксУ% пт. OTR where He is the negative pressure created by the bypass booster, kg / m2; Nga - the vacuum created by the gas analytic booster, kg / m2; a - coefficient of aerodynamic drag of the tube, kg cm / m4; (trmax - the length of the tube taking a sample from the control point furthest from the central point, m; dip - internal diameter of this tube, m; Vonr - gas flow rate in the tube, corresponding to the optimum value of the sample flow through the gas analyzer unit, m / s; The volumetric flow rates in each channel are established by alternately connecting with fully open tube rotameters to the gas analysis pump, the channel with the minimum volumetric air flow is determined and the corresponding minimum flow rate in all other channels is established, alternately connected to the gas analysis pump.