Refrigeration compressor in the operation, the movement of the surface of the need for refrigeration oil lubrication, screw and rolling rotor refrigeration compressor also need to inject a certain amount of refrigeration oil into the machine, from the sealing and cooling effect. Therefore, these compressors in the exhaust will inevitably bring a certain amount of refrigeration oil. After the refrigeration oil enters the refrigeration system, it forms an oil film on the surface of the heat exchanger, which affects the heat transfer process in the heat exchanger. In the evaporator, the evaporative temperature of the refrigerant is higher than the saturation temperature under the evaporation pressure Is for the Freon system), or occupies a portion of the evaporator volume (for the ammonia system), so that its heat transfer surface can not fully play a role. In addition, after the oil enters the system, the compressor may be deficient. Therefore, it is necessary to try to separate the refrigerating machine oil and recover it, and it is necessary to set the separation and collection equipment of the refrigerating machine oil. Some oil separation equipment is installed in the compressor side, through the float valve, so that the refrigerator oil to the crankcase; for ammonia refrigeration device, the Big Oil Expeller installed in the condenser before the oil separated from the oil collector , And then processed.
The most basic separation factor for Big Oil Expellers is:
(1) The density of the oil droplets and the refrigerant vapor is different.
(2) sudden expansion of the channel area and reduce its flow rate.
(3) change the flow direction of the fluid.
(4) fluid and the impact of the container generated by the kinetic energy is different.
On the basis of the above basic separation factors, the other oil separation measures were used to separate the refrigerating machine oil. For the refrigerating machine oil in the vapor state, the temperature is lowered by washing or cooling, and the mixture is condensed into oil droplets and separated. There are a number of Big Oil Expellers used to set the filter layer method to enhance the separation of frozen oil effect. According to the different oil separation principle, the Big Oil Expeller has gravity, centrifugal, packing, washing and filtering.
Centrifugal Big Oil Expeller for medium and large refrigeration systems. The oil is separated by the centrifugal force when the air flow is in the form of a spiral flow. The exhaust of the compressor enters the separator in the tangential direction and flows in a spiral flow along the guide vane. The oil droplets in the refrigerant vapor are separated under the action of centrifugal force , Along the inner wall of the shell, and the vapor is passed through the filter and then from the intermediate pipe. The separated oil product is present in the lower part of the separator and is returned to the compressor via the automatic control valve or periodically into the oil collector.
Filler Big Oil Expeller for medium and small refrigeration systems; vertical and horizontal two types of installation, in the separator shell with metal mesh, ceramic ring or metal shavings and other fillers, oil droplets rely on air velocity Reduce, change its flow and filter layer of the role of filtration and separation. The steam flow rate in the shell should not be higher than 0.5 m / s. One of the stainless steel wire mesh for the Big Oil Expeller separation efficiency of the highest, up to 96% -98%, but the resistance is relatively large.
The types of Big Oil Expellers are washing, centrifugal, packing and filtration. Compressor in operation, always have lubricants discharged together with the exhaust, when the oil into the condenser and evaporator, affecting the heat transfer effect, it should be installed in the exhaust pipe Big Oil Expeller to reduce the oil Human system. When the Big Oil Expeller is arranged, note the following: a. The position of the Big Oil Expeller should be considered with the piping. Washing Big Oil Expeller should be as close as possible to the condenser, the inlet pipe should be from the bottom of the condenser outlet, and the inlet must be lower than the condenser outlet 0.2 ~ 0.3m. b. The ammonia Big Oil Expeller should be as far away as possible from the compressor so that the exhaust gas is supplied with additional cooling before entering the ammonia Big Oil Expeller to improve the separation effect. c. (Such as chillers, walls, pipes, etc.) defrosting with hot ammonia ammonia Big Oil Expeller, can be set in the compressor room. d. When two or more Big Oil Expellers are used, the exhaust pipe with the compressor to the Big Oil Expeller should be made to distribute the exhaust gas evenly to ensure that the oil separation effect is good. e. There is no pressure gauge and safety valve on the Big Oil Expeller.
Installation of the Big Oil Expeller Install the Big Oil Expeller, first check the basic elevation and centerline dimensions, and then install it. Due to the Big Oil Expeller into the high-pressure gas is easy to produce vibration, anchor bolts should be used double-nut or pad spring and tighten.