The use of vacuum pumps to recover waste gas and tail gas is becoming more and more important for clean environment, and compressors need to be installed. In the actual use process, the equipment emits a large number of harmful corrosive gases into the supporting vacuum system, which causes the damage of the vacuum pump in the system and shortens the service life of the equipment. Iodine in harmful gases condenses into crystals and mixes with vacuum pump lubricants to form oil contamination, which is harmful to equipment. Therefore, it is necessary to design a process system to treat the exhaust gas (mainly iodine) in order to maintain the normal use of the system equipment.
In many countries, environmental regulations prohibit the release of corrosive and toxic gases into the atmosphere. This regulation has a wide range of applications and covers many areas of hydrocarbon processing (HPI). So at present, many hydrocarbon processing units either close the loop and install the vacuum system for tail gas recovery, or make technical improvements to the existing system.
Vacuum Pump Exhaust Gas Treatment Scheme
1. The exhaust gas from the system is stored in 2000 m3 vacuum spherical tank. The exhaust gas is heated by a tubular heat exchanger and then enters the bottom of the adsorption tower. The exhaust gas is filtered through porous sieve plates and 320 mesh stainless steel wire mesh at 3-5 layers to filter aerosols (particles and dust). Then it enters the coarse porous silica gel layer and alkali lime layer to remove water and chlorine in the exhaust gas so that the follow-up equipment can get it. Protect from corrosion.
2. Gas continues to rise, removing gaseous iodine and trace chloride from exhaust gas by adsorbing activated carbon layer, reducing toxic chloride emissions and iodine damage to the lubrication system of back vacuum pump, reducing faults and prolonging its service life.
3. The adsorbed gas is pumped out by vacuum pump from the gas outlet at the top of the adsorption tower, and the chlorine content in the gas is sampled and analyzed. If the chlorine content in the gas exceeds the stipulated value of the “Air Pollutant Discharge Standard”, the chlorine is removed by alkali water spraying and washing, so as to meet the discharge requirements of the national standard.
Liquid ammonia finishing process has exhaust gas discharge, its composition is water vapor, air and ammonia, ammonia gas is harmful gas, affecting the health of the environment, to reduce emissions, use of vacuum pump to recover waste gas, on the one hand, can reduce costs, on the other hand, can protect the environment.
The waste gas recovery method includes the following steps:
(1) The exhaust gas is dissolved in water by spraying through the exhaust gas recovery system to form a certain concentration of recovery liquid, the liquid temperature is 20-50 C;
(2) The recovered liquid is distilled and condensed through the waste liquid distillation system. The shell heat source of the waste liquid distillation system is atmospheric pressure water vapor at the temperature of 100-140 C. The waste liquid is recovered through the tube layer of the waste liquid distillation system, which is extracted by vacuum pump and in a negative pressure state. The negative pressure state can accelerate the separation of solvent and water under the action of the outer heat source of the shell layer. The use of vacuum pump to recover the waste gas produced in industrial production has a high efficiency. It can be reused after recovery. It can save energy and protect the environment. It can effectively solve the problem of waste gas treatment and greatly reduce the impact of irritating gas on the health of operators.