Kylin Chemicals have been engaged in the research & manufacturing a selected range of Chemical Intermediates & specialties for over one decades,such as hydroxylamine sulfate.
We have the expertise in manufacturing high quality Aromatic Hydrocarbons specialties, serving our customers worldwide in the field of pharmaceuticals, agrochemicals, organic synthesis and coatings, etc. Our main aromatic hydrocarbon product include 2,3-Dihydroindene, Decahydronathalene, Tetrahydronaphthalene, Carbazole, Acenaphthene and Phenanthrene,1 2 3 4-tetrahydronaphthalene, etc.
Our manufacturing base have the advanced DCS operated hydrogenation & rectification facilities, effective quality-control systems, and a very professional technical team, assuring the quality, stability and sustainability to meet/exceed our customers` needs.
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1, to determine the working vacuum range must first check to determine the degree of vacuum for each process requirements. Because each process has its own vacuum range, it must be carefully studied and determined.
2. Determine the ultimate vacuum degree Check the ultimate vacuum degree of the vacuum pump system on the basis of determining the degree of vacuum required by the process, because the ultimate vacuum degree of the system determines the optimal working vacuum degree of the system. In general, the ultimate vacuum of the system is 20% lower than the working vacuum of the system and 50% lower than that of the foreline pump.
3, the type of gas to be pumped and the amount of gas extracted to determine the process requirements of the type of pumping and pumping. Because if the type of gas being pumped reacts with the liquid in the pump, the pump system will be contaminated. At the same time, consideration must be given to determining the appropriate venting time and the amount of gas generated during the pumping process.
4. The vacuum volume check determines the time required to reach the required vacuum level, the flow resistance and leakage of the vacuum piping.
Consider the pumping rate required to maintain the vacuum after achieving the required vacuum level under certain process requirements.
5, vacuum pump formula S = 2.303V/tLog (P1/P2)
among them:
S is the vacuum pumping rate (L/s)
V is the volume of the vacuum chamber (L)
t time required to reach the required vacuum (s)
P1 is the initial vacuum (Torr)
P2 is the required vacuum (Torr)
E.g:
V=500L
t=30s
P1=760Torr
P2=50Torr
Then: S=2.303V/tLog(P1/P2)=2.303x500/30xLog(760/50)=35.4L/s
Of course, the above formula is only a theoretical calculation result, there are several variables that are not taken into account, such as the flow resistance of the pipeline, leakage, the flow resistance of the filter, the temperature of the gas being pumped, and so on. In fact, safety factors should also be taken into account.
The vacuum pump is a rotary positive-displacement vacuum pump that must be used with a foreline pump in order to use it in a wider pressure range. Larger pumping speed is not sensitive to dust and water vapor in the pumped gas. Widely used in metallurgy and chemical industry , food, electronic coating and other industries. 
Vacuum pump selection points and uses
The function of the vacuum pump is to remove gas molecules from the vacuum chamber and reduce the gas pressure in the vacuum chamber so that it can reach the required vacuum level. Generally speaking, there is a large range from atmospheric to extremely high vacuum, and so far no vacuum system has been able to cover this range. Therefore, in order to achieve different product process specifications, work efficiency and equipment operating life requirements, different vacuum sections need to select different vacuum system configurations. To achieve the best configuration, consider the following points when choosing a vacuum system: