Preliminary application of the hottest Gore membra

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Gore membrane liquid filter, as a high-tech product, is gradually popularized and used in the sulfur recovery system of wet desulfurization in coking gas industry. Its application will change the traditional sulfur recovery process, greatly improve the current situation of the sulfur recovery system, be of great benefit to reducing the suspended sulfur content in the circulating desulfurization liquid, and its significance to environmental protection will also be accepted by more coking gas industries. Gore membrane liquid filter has been preliminarily applied in the water gas desulfurization system of our company, and has achieved certain results. 2 filtration principle filtration is the operation of separating solid particles from heterogeneous materials containing solid particles through porous materials such as cloth and. The desulfurization solution contains many suspended solid particles with small particle size, which agglomerate with each other by electrostatic and molecular gravity. Therefore, desulfurization solution is a heterogeneous suspension containing solid sulfur particles, and the filtration of desulfurization solution belongs to suspension filtration

The filtration method of Gore membrane liquid filter is to use membrane for surface filtration, which is different from the general filtration technology, that is, the expanded polytetrafluoroethylene material is compounded on the bottom support material with a special process to make a filter bag for effective filtration. This unique filtration method enables all the suspended sulfur in the solution to be collected on the surface of the membrane. Because the membrane has excellent non adhesion and very small friction coefficient, the filter bag will not be blocked at all, and the suspended solids in the solution are effectively collected. 3. Process comparison of sulfur recovery system 3.1 the sulfur recovery bridge needs a very low depth. It communicates through the serial port (COM number) behind the computer. The process flow of the sulfur recovery system

the company adopts A.D.A wet oxidation self-priming regeneration desulfurization method, and its sulfur recovery system adopts the traditional process of sulfur melting in sulfur foam tank and sulfur melting kettle. The rich liquid with high sulfur content is pumped into the self-priming regeneration tank for regenerative flotation. The floatated sulfur enters the sulfur foam intermediate tank, and is pumped into the sulfur foam tank for mixing and steam heating. The temperature is about 80 ℃, and then it is static and stratified. The clear liquid returns to the system, and the sulfur slurry enters the sulfur melting kettle, where it is jacketed and heated by indirect steam to ℃ for stratification. The clear liquid is pressed into the kettle liquid sedimentation tank, and the operation is repeated until the kettle is full, and then heated and evaporated to ℃, Hours later, put the molten sulfur into the sulfur crystallization basin for natural cooling and forming. See Figure 1 for the process flow

process system defects:

3.1.1 inherent defects of the system

(1) the retention time of the solution in the self-priming regeneration tank is too short, and the design specification requires min, while the recalculation is only 6min. Therefore, press "query/3" again, the regeneration reaction of the solution in the regeneration tank is insufficient, the sulfur particles are fine and sticky, and cannot be suspended well, resulting in poor solution. Moreover, due to the time difference, the formation reaction of sulfur is generated on the tower plate or packing, which will lead to the short-term increase of tower resistance in serious cases

(2) the water gas from the gas holder contains a certain amount of tar dust, which is 10mg/l into the tower and mg/l out of the tower after being sprayed by the solution. The tar dust enters the circulating solution system, resulting in the gradual increase of the solid particle content of the solution and bonding with the sulfur slurry with high viscosity, which has adverse consequences on the tower plate and packing, and finally leads to the increase of the resistance of the tower body

3.1.2 the high content of particles in the solution brings many adverse factors to the system

after sulfur is heated in the foam tank, especially in the sulfur melting kettle, part of the pressed clear liquid with hard sulfur particles enters the sump, and when it returns to the reaction tank, some hard particles also enter. However, the regeneration tank cannot flotation fine hard particles, so the solid content in the lean solution remains high, and the suspension of the solution is as high as g/l, realizing the combination of tradition and innovation. The solution with high solid content enters the swirl plate tower and the wooden lattice packing tower, causing the resistance of the tower body to rise faster. The tower body operates for months, and the resistance of the swirl plate tower is greater than 10000pa, and the resistance of the wooden lattice packing tower is greater than 4000Pa. Therefore, on average, each tower group needs to be cleaned twice a year, and each tower group needs 100000 yuan, which is a large expense. At the same time, the harder particles will cause serious wear and tear to the solution circulating pump, causing continuous damage to the circulating pump in the second half of 1997 and the first half of 1998, seriously affecting the quality of gas production, and the cost of maintenance materials is more than 1 million yuan

3.1.3 it is difficult to control the content of disulfide in the desulfurization solution

during the heating and cleaning process of sulfur foam tank and sulfur melting kettle, the solution is heated to ℃ and ℃ respectively. Due to the high temperature, the side reaction is accelerated, resulting in the increase of the content of disulfide (NaCNS, Na2S2O3) in the clear solution, and the deteriorated dark brown clear solution enters the circulating solution system, resulting in the destruction of effective components in the desulfurization solution and accelerating the corrosion of the solution to pipelines and equipment, And affect the desulfurization efficiency

3.1.4 high steam consumption

because the sulfur foam needs to be heated to ℃ in the foam tank and the sulfur melting kettle during the feeding and cleaning process, and then heated to about 140 ℃ in the sulfur melting process, a large amount of steam needs to be consumed in the whole process, and it is estimated that 4.5 tons of steam/ton of sulfur will be consumed

3.1.5 environmental protection and corrosion problems

(1) in order to keep the system normal in the sulfur recovery process, a large amount of sulfur slag needs to be cleaned regularly, and at the same time, a certain amount of waste desulfurization liquid needs to be sent to biochemical treatment. The content of COD and s in this part of waste liquid is high, with the content of COD as high as 40000mg/l and the content of s as high as 1500mg/l, which seriously impacts the biochemical activated sludge and brings great pressure to the biochemical treatment

(2) when sulfur foam is heated, a large number of acid gases (H2S, CO2, etc.) are produced. These exhaust gases not only corrode plant equipment, but also deteriorate the operating environment, affecting the physical and mental health of operators. Figure 13.2 sulfur recovery filtration process flow

the sulfur foam suspended from the regeneration tank enters the sulfur foam intermediate tank. It does not pass through the foam tank or heated to a higher temperature by steam, but is directly sent to the filter by pump for filtration. The sulfur paste enters the sulfur melting kettle, and the filtered clear liquid returns to the lean liquid system. See Figure 2 for the process flow diagramt3701.gif (2922 bytes)