Vacuum evaporation concentration transportation sterilization dry packing and vacuum mixed emulsification
Mainly used for vacuum evaporation, concentration, distillation, crystallization, drying, extraction, sublimation, vacuum mixing, vacuum reaction, absorption, vacuum filtration and conveying materials and other processes are completed with the help of vacuum equipment, the use of crude low vacuum equipment are mostly W mechanical, water ring, rotary vane and slide valve vacuum pump.
In the pharmaceutical equipment industry, there are vacuum evaporation, vacuum concentration, vacuum transportation, vacuum sterilization, vacuum drying, vacuum packaging and vacuum mixed emulsification and other vacuum equipment. Used by these devices must be equipped with a vacuum pump, vacuum pump with liquid ring vacuum pump, water injection pump and steam jet pump, the several kinds of vacuum pumps can be directly pumping water vapour and several common rotary vane pump, reciprocating pump, plunger pump, roots pump and so on, although they cannot pumping water directly, but can use if asked to be associated with condensation space and the surrounding environment clean, no pollution, also can be applied to all kinds of dry pump dry pump more responsibility at present, but it is the future development direction.
Pharmaceutical water ring vacuum pump vacuum evaporation
1. Working principle liquid ring vacuum pump belongs to positive displacement pump and its working medium is liquid. If the liquid is water, it is called water ring vacuum pump. Its working principle, as shown in the Yu 1 a eccentric impeller (rotor) installed in the column shell, when the impeller rotates, due to the effect of centrifugal force, make the water in the pump shell to jilt to form such as the thickness of ice water ring b ring and impeller tangent form crescent-shaped space d, this space cavity is divided into several small rooms, and gradual change along with the impeller rotation. When this space becomes large from small, the suction cavity e pump is formed to absorb gas. When the crescent space becomes large, the exhaust cavity f pump is formed to discharge gas, thus achieving the pumping effect of the pump.
2. Using liquid ring pump, it is impossible to get the inlet pressure lower than the working liquid vapor pressure. If the liquid vapor pressure is close to the inlet pressure, cavitation will occur and damage the pump. Such as ice in 15 c when steam pressure is 103 pa, to avoid cavitation, allowing water ring pump inlet pressure is 3.3 X103Pa. If need to inlet pressure is lower than the value l should be even more low vapour pressure of medium such as kerosene, styrene and ethylene glycol limit pressure of 6.7 X from the pump discharge side flow of gas and liquid mixture into the separator in the separator gas-liquid separation, not out of gas containing liquid with temperature of steam pressure, steam content. The operating mode of the liquid ring pump is shown in the table from the two aspects of working liquid price and environmental protection. The main feature of this operation mode is that the amount of new liquid is greatly reduced. Most of the liquid is added into the cold liquid before the pump inlet from the separator, so that the inlet temperature of the pump is basically kept constant.
If the liquid ring pump is used to remove toxic and harmful gas, or the high price of working liquid must be used due to work needs, the gas separated in the separator cannot be emptied and should be recycled, while the separated liquid must be cooled by the heat exchanger to the normal working temperature of the pump liquid, and then all the separated liquid must be returned to the pump.
At present, the main types of domestic water ring pump are SZ, SZB, SZH, SZZ, SZL, SK and ZBE1. Z water ring pump can be used to remove non-corrosive, insoluble in water, or do not contain solid particles of gas and air; ZB type is cantilever type, the use characteristic is basically same with SZ type; SZH water ring vacuum pump is mainly used for air extraction, and can also be used in vacuum filtration device: SZZ and SZL are directly connected pumps, the purpose is the same as ZS pump; SK water ring type vacuum pump is a kind of high efficiency double function of water ring vacuum pump work gas temperature at 10 ~ + 40 ° C is widely used in vacuum drying, vacuum dehydration, vacuum filtering device such as a plenty of water vapor overflow ZBZ1 type water ring pump is the introduction of German technology development of energy saving product use with SK water ring type vacuum pump.
1.3 operating characteristics normally, the operating condition of water ring vacuum pump is that the air temperature of the pump is 20CI and the relative humidity is 70%, and the air inlet pressure is 101.325kPa, and the working liquid of the pump is 15C water. The temperature and vapor pressure of the working liquid seriously affect the pumping speed. The partial pressure of the working liquid in the extraction chamber and the impeller chamber increases with the increase of temperature. When the removed gas is 20C dry air and the pump working liquid is water, the pumping speed SU2 at different temperatures is given in the equation 3. With the pumping speed at 15C, a pressure p is given. The influence of the working liquid temperature on the pumping speed of single-stage pump, and the pumped gas also has an influence on the pump performance. If the pumped gas is composed of a mixture of air and steam, condensation may occur when the pumped steam is in contact with the cold working liquid, and then the pumping speed increases. When 15C water is used as the working liquid, the extraction speed of a certain amount of air and water vapor mixture at different temperatures is the ratio of 3 (35.5) to 20 (Su) of 20C dry air. Of course, the ratio of air to water vapor will affect the pumping speed differently.
If the pharmaceutical vacuum pump transports dry air, due to the small heat capacity of the dry air, the influence of the temperature of the vapor saturated gas transported by the single-stage pump on the pumping speed is quickly cooled to the temperature of the working liquid. The large temperature difference between the pumped gas and the working liquid reduces the volume of the gas, which will increase the pumping speed of the liquid ring pump. If the pumped gas is dissolved in the working fluid, it will be released as it enters the inlet side of the pump with the working fluid. As a result, the pumping speed will be reduced. Liquid ring vacuum pump power required by the working liquid viscosity, density, flow rate and the impact of the outlet pressure should be paid attention to the operation.