This paper introduces the mature application and potential application of vacuum equipment in coal industry, and puts forward the basic national policy that the application of vacuum pump equipment can meet the safety requirements and conform to the national circular economy, energy-saving economy and sustainable development. The development and improvement direction of vacuum pump equipment used in coal industry are expounded.
Water Ring Vacuum Pump/Compressor in Coal Industry
When the gas drained from underground comes to the ground, it contains air and water for gas drainage, and the pressure is low, so it can not be used directly. It must go through the bad working environment of the water separation mining area. Therefore, the water ring vacuum pump/steam, air, water and other processes are required, and then after pressurization, it enters each compressor to extract a large and true amount of gas. High void and reliable operation. Now the users and working sections of water ring are in use. Using ordinary SKA(2BE3) water-type vacuum pump/compressor is designed and manufactured by international advanced technology. The air-ring compressor can be equipped with anti-tempering, dewatering and monitoring system to reach 500-40000m3/h, which can fully meet the requirement of coal mine forming process, because the working principle of water-ring compressor is isothermal pressure industry. Needs. It is not only suitable for coal-bed methane drainage while excavating and mining, but also suitable for coal-bed methane drainage in the process of over-normal mining. Therefore, it is more and more widely used. Exhaust pressure 0-01 MPa
Caving, that is, abandoned mine, mining roadway CBM drainage. Compressors are suitable for pipe network pressurization and civil use. Exhaust pressure is 0.2-drilling method for drainage. Coal seam drilling is loosened by loosening technology. Compressors with an increase of 0.4 MPa are suitable for power generation, chemical industry and other industries. Compressing the release area and conduction of enriched coalbed methane can make the rapid release of coalbed methane. Reducing water ring vacuum pump/compressor releases less in the process of gas drainage and transportation in coal mines. This method works well, and its application is shown in Figure 1. And the utilization rate of CBM is high.
Water Ring Vacuum Pump/Compressor in Coal Mine Gas Drainage
1 – Water discharger – explosion-proof, temper-proof device- pipeline valve – instrument for measuring negative pressure, gas concentration and flow rate;
Water Ring Vacuum Pump in Coal Industry
Gas Drainage in Waste Mines
In traditional ventilation devices, gas drainage is very difficult. Water ring vacuum pump/compressor can not only realize gas drainage, but also collect gas, making use possible and practical.
Coal chemical technology
Coalbed methane can be used as raw materials for many chemical products such as ammonia, methanol or formaldehyde. Like other chemical processes, it consists of decompression, pressurized reaction, synthesis, distillation and other processes. Water ring vacuum pump/compressor is an indispensable equipment to solve process problems.
In coal preparation process, water-ring vacuum pump/compressor acts as a vacuum filter section. Because of the pre-separator, it can stabilize pressure and separate liquid, so it can impact with air flow and water.
Water ring vacuum pump/compressor is the main pump, equipped with separation, dust removal, protection and other devices to achieve dust recovery and utilization and environmental protection in mining areas. QS series dust collection and conveying equipment has been successfully applied in coal industry.
ZG cable vacuum dryer uses water-ring vacuum pump/compressor as pumping equipment. It uses low voltage and high current inside the cable to generate heat to complete cable drying, and the cable is not damaged by aging. It changes the traditional process of external heating and normal temperature drying. It is a revolution of underground electrical equipment drying technology. The application of water ring vacuum pump in electric drying process is shown in Fig. 2.
Application of Drawing Water Ring Vacuum Pump in Electrical Cable Drying Technology
1-drying chamber; 2-pre-separator; 3-water ring vacuum pump; 4-steam-water separator;
5-cycle heat exchanger; 6, 7, 8, 9, 10-pipeline valves
Flame retardant tape production
In the process of producing anti-static and anti-combustion conveyor belts, vacuum slurry immersion process is needed to make anti-static and flame retardant enter the inner part of conveyor belts. The technological process is shown in Fig. 3. The process uses ZF vacuum generator to realize the immersion of fabrics to meet the safety requirements of flame retardant and anti-static.
This process is used in some coal mine ground industry, replacing the original spraying process, which is more safe and reliable. This process can also be used to treat underground clothing, tools, etc.
Figure 3 Mining conveyor belt leaching process
1 – vacuum chamber; 2 – front separator; 3 – water ring vacuum pump; 4 – steam water separator;
5-cycle heat exchangers; 6, 7, 8, 9, 10, 11, 12-pipeline valves
2. Renewal Requirements for Vacuum Equipment in Coal Industry
Gas is generally adsorbed on the coal seam, through three production processes: drainage, pressure reduction and gas recovery. Vacuum pumps used in coal mines range from SZ Series in the Soviet Union to SK series independently developed in China to SKA (2BE3) series, which is in the leading position today. They adopt the most advanced technology in foreign countries. Every change is directed towards energy saving and reliability. For example, in the 1960s and 1970s, the maximum air volume of SZ-4 vacuum pump was 1700m3/h, the efficiency was only 20%-30%, the largest SK-85A in the 1980s, the gas volume was 5100m3/h, and the efficiency could reach 30%-40%. Now, through joint venture development and production, SKA (2BE3) -720 water ring type vacuum pump with advanced foreign technology is true. Air pump/compressor, the gas volume can reach 40 000 m3/h, the efficiency is 45%-60%, and the operation is more reliable.
Development Direction of Vacuum Equipment for Coal Mines
Traditionally, equipment manufacturers mainly manufacture vacuum pumps, and the equipment matching degree is low. Because of the inconsistent configuration, the main equipment is inefficient, and even because of professional differences, the equipment can not work properly. Therefore, complete equipment is the requirement of coal industry for vacuum pump plant, and also the direction of product development. According to the characteristics of coal mine, providing personalized vacuum equipment is also the direction of product development in our vacuum equipment manufacturing industry.
Large water ring vacuum pumps are widely used in coal industry, so energy saving and consumption reduction are more important. Vacuum industry manufacturers should devote themselves to the research and development of safety, energy saving, environmental protection, chemical and other equipment in China’s coal industry. They should develop a vacuum unit integrated with machinery, electricity and instrumentation, equipped with complete steam-water separators, circulating heat exchangers, on-line measuring and controlling instruments, automatic control systems, valve assemblies, etc.