Product Description 
 ZLD-2-type drilling multi-level flow meter for the determination of coal seam drilling of gas emission to the initial velocity to predict the working face of coal, coal and gas outburst hazard and inspection to prevent the anti-conflict effects of coal and gas outburst measures. Ahead of drilling an effective radius of influence can also be used to determine the anti-sudden. ZLD-2-type drilling multi-stage flowmeter nozzle throttle principle, when the gas flow through the nozzle, the jet cross-section production contraction, on both sides of the nozzle of the pressure difference, the greater the flow, pressure greater. When certain pressure difference, the larger the nozzle aperture, the greater the flow through the gas. Flowmeter five different nozzle design, nozzle, switch to a different aperture to obtain different flow measurement range. 
 Applications 
 For underground direct determination of the mining face, regional the CROSSCUTTING coal face and seam highlight the risk of supporting instruments. Principle construct 
 The flowmeter uses spray throttle principles of design. When the gas flow through the nozzle, the jet cross-section contraction, on both sides of the nozzle of the pressure difference. The greater the flow, the greater the pressure difference. When the pressure must tear, the larger the nozzle aperture, the greater the flow through the gas. Flowmeter designed with five different aperture nozzle, replacement nozzle of different pore sizes to obtain different flow measurement range. The instrument structure is simple, its structure as shown. The main body of a block of plexiglass plate processed by a column of water, sprayed intake Tsui 3 cocks, 4, 5 and the nozzle base composition. The apparatus Dimension for 250X120X34mm weighs about 0.8Kg. 
 Determination of Step 
 A. Before the test preparation 
 To the water column of water injection, and both sides of the surface adjusted to zero-scale line; the sealing performance of the inspection equipment, need to replace the new "O"-ring seal failure; according to the size of the seam is expected to flow, the flow range is more close to the nozzle installed in the flowmeter on the nozzle base. 
 Two. Methods and steps 
 Supporting the use of the flowmeter and the special JN-1 capsule sealing. During the working face of coal and gas outburst forecast and anti-conflict test the effect of test, the drilling is finished, quickly insert a special sealing device sealing. The sealing device exhaust pipe with the flow meter inlet Tsui Hose connections, to maintain the flow meter water column total was the location of the plumb bob. At this point, the emissions of coal gas through the measurement chamber, the exhaust pipe to connect the hose, flow meter nozzle discharge, pressure difference on both sides of the water column meter. Read the water column total pressure value. 
 The above determination process requires to be completed in 2min.