Roots Rotary Plate Vacuum Unit for Medical Vacuum Refrigeration
Roles of Roots Vacuum Pump in Transportation and Storage
(1) Temperature crude oil is always accompanied by hydrocarbon gases such as methane, ethane, propane and hydrogen sulfide in varying amounts of low molecular weight. These gases must be removed before storage, transportation and distillation to stabilize the crude oil. At the same time, the components of aviation gasoline taken away by the volatilization of low molecular hydrocarbons, especially their isomers (hydrocarbons with high seismic performance in tender materials), can be recovered and utilized. In order to reduce the excessive loss of crude oil during storage and transportation, stabilize the composition of crude oil and gasoline products, and change the composition of fractions easily in storage, large vacuum crude oil stabilization units have been established in some foreign oilfields to degasse crude oil at a vacuum of 310-350 mmHg in order to stabilize crude oil.
(2) In order to store propane and butane separated from crude oil conveniently in sickle under atmospheric pressure, vacuum refrigeration was used to liquefy the crude oil by deep freezing in the past. But at present, many foreign factories use vacuum refrigeration to evaporate part of the frozen propane in vacuum. It is easy to obtain a low temperature below 148 C, and then propane and butane are separately at - 48 C and - 10 C. Liquefaction at low temperature, storage or transportation in tanks.
(3) When the air discharged from the tank is not loaded into the tank with stable crude oil, it will cause a lot of losses when the tank "breathes" because of the volatilization of light components. If the tank is emptied by vacuum device, liquefied petroleum gas (propane and butane) and liquefied natural gas (methane and ethane) can be removed, recycled and utilized.
Roots Vacuum Pump in Medical Vacuum Refrigeration
Vacuum freeze-drying is a better method of material dehydration at present. It can freeze the freeze-dried material in advance, and then sublimate the moisture of the material at low temperature and low pressure to achieve the purpose of dehydration. Sublimated water vapor is collected by condensation. After this vacuum freeze-drying, the substance becomes dehydrated.
After vacuum freeze-drying, the enzymatic activity of the material is weak, the original chemical and physiological properties are basically unchanged, the drying material is porous structure, the volume is basically unchanged and easy to recover. In particular, the vacuum freeze-dried substances can be preserved for several years without deterioration.
Condenser is a device for condensing and sublimating water vapor. Its working overflow can reach - 45 C to - 60 C. The refrigeration source is provided by two 2F6.3 Freon refrigeration units.
The vacuum unit of dryer is composed of two rotary vane mechanical vacuum pumps and one Roots mechanical booster pump. Vacuum unit is connected with drying box and condenser through vacuum pipeline and vacuum valve to form a sealed vacuum system. The vacuum unit is equipped with an electric contact vacuum meter, which can automatically control the starting of Roots pump according to the pre-selected vacuum position. There is a vacuum butterfly valve in the vacuum pipeline between the drying box and the condenser, which can be switched on and off at any time according to the use requirements. The bottom of the condenser is equipped with branch vacuum pipeline leading to the hot air blower, and the middle valve is separated by 50 butterfly valves. The function of this valve and branch pipeline is for defrosting and drying of the condenser. The vacuum branch pipeline above the Roots pump is the passageway when the mechanical vacuum pump is used alone. It is equipped with solenoid valves. When the Roots pump is started, the width will automatically close. The vacuum pipeline is equipped with a solenoid belt bleeding cut-off valve. When the vacuum pump stops, the vacuum pipeline can be automatically closed. At the same time, air is put into the vacuum pipeline to avoid the vacuum pump oil rushing into the vacuum pipeline due to negative pressure. A corrugated hose is installed between the connecting pipes of the vacuum pump to prevent vibration from being transmitted to its components during operation.