The cascading cryogenic units produced by YORK Corporation of the United States are widely used in pharmaceutical production. The unit includes high temperature car and low temperature car and low temperature car, design working condition, coolant supply temperature -75 ° C, evaporation temperature -80 ° C, condensation temperature -20 ° C, cooling capacity is 251.2 KJ (60,000 cards). The high temperature vehicle refrigerant is R22, the low temperature vehicle refrigerant is R13, the refrigerant carrier is R11, and the low temperature vehicle evaporator is a two-flow shell-and-tube type full liquid evaporator.
First, the oil level of the oil separator is falling too fast
1. The phenomenon of failure starts the test of the cryogenic unit, and the technical data of the R22 high temperature car and the R13 low temperature car are normal, and the system has a good cooling effect. However, after the shutdown, the oil level of the oil separator was reduced by about 10 mm through the oil sight glass. Turn it on again, stop after running for a while, and the oil level drops by about 10mm.
2. Cause Analysis The oil may leak. The oil and gas separator, the oil cooler, the essential oil filter and its pipeline were inspected, and no oil leakage was found, indicating that the system had no external leakage.
The oil may leak inside. The oil cooler is a shell-and-tube heat exchanger, which circulates water to the tube and deep-cools the oil to the shell. The tube and the expansion joint may leak, check the oil cooler tube. First, open the circulating water drain valve at the head and put the circulating water into a clean basin. No oil traces were found in the circulating water. It is preliminarily determined that the oil cooler does not leak.
Close the oil cooler circulating water inlet and outlet valves, remove the oil cooler at both ends, and the oil cooler oil pressure gauge pressure is 0.8Mpa, which is the pressure of the R13 system. The oil cooler was leak-tested, and one end of the tube was plugged with rubber, and the other end was inspected with soapy water one by one. No oil leakage was observed. When the oil cooler is working normally, the pressure can reach 1.5 MPa. To this end, the oil cooler is gradually pressurized to 1.5 MPa with nitrogen. After inspection, there was no leakage.
The oil may enter the R13 system, slightly open the full-liquid evaporator drain valve and find that there is indeed oil in it. Possible reasons are: the unit is overloaded too fast, causing the unit to run oil; the oil separator is not good in oil separation; the heat load is too low, causing the evaporation temperature to be too low; the suction expansion valve is too large; the cooling water is too large to open, condensation The temperature is too low.
Re-open the unit and slowly increase the load to make the unit operate normally. Careful observation of the oil level of the oil and gas separator mirror, found that the unit did not drop in the operation of the oil, indicating that the above reasons can not cause oil. However, after stopping, the oil level dropped by about 10 mm and the compressor was found to be reversed. Indicates that the suction check valve is not closed tightly or the solenoid valve is malfunctioning. After inspection, the solenoid valve is intact.
The suction check valve and the exhaust line are controlled by a solenoid valve. During normal operation, the solenoid valve is closed, and the suction check valve is opened by the suction pressure to supply air normally. When parking, the solenoid valve opens, the exhaust pressure collides with the suction check valve, and is exhausted by high pressure. Close the suction check valve to prevent the compressor from turning up.
The compressor has reversed, indicating that the suction check valve is not closed tightly. The oil and R13 gas flow backward from the high pressure part of the oil separator to the suction line and the low pressure part of the evaporator, causing the oil level of the oil separator to drop and run oil.
3. Solution When the device is in normal operation, it can be adjusted to the automatic running state. When parking, first reduce the load of the low temperature car to 5%, then manually close the suction valve, press the parking button after the Zui, the device can stop running. With this method, the oil level is no longer lowered, that is, the lubricating oil does not enter the R13 system.
Second, the cooling capacity has dropped significantly
Fault phenomenon
Technical data of R22 high temperature car: suction pressure 0.21Mpa, suction temperature -25°C, exhaust pressure 1.39Mpa, exhaust temperature 71°C, oil pressure 1.37Mpa, oil temperature 47°C, compression ratio 3.5, load 100%, percentage The current is 100%, the oil filter pressure difference is 0, and the oil level is normal.
R13 low temperature car technical data: suction pressure 0.13 Mpa, suction temperature -47 ° C, exhaust pressure 1.37 Mpa, exhaust temperature 72 ° C, oil pressure 1.35 Mpa, oil temperature 55 ° C, compression ratio 3.4 load 100%, percentage current 100%, oil filter pressure difference 62Pa, oil level is normal.
The unit is operated according to the above parameters, and all parameters are normal, but the unit is slow in cooling, and the temperature is reduced by 7~8 °C per hour.
2. Analysis of the causes The temperature monitoring instrument of the cryogenic vehicle was carefully observed. It was found that the outlet temperature of the refrigerant R11 was only -31 °C, which was very different from the suction temperature of the low temperature vehicle -47 °C, and the outlet temperature of R11 should be -57 °C. The evaporator heat exchange is not good. And the refrigerant pressure gauge of the evaporator shows an inlet pressure of 0.33 MPa and an outlet pressure of 0.3 MPa. The normal inlet and outlet pressure difference should be 0.05Mpa, the actual pressure difference is only 0.03Mpa, and the pressure difference is small. The inlet and outlet pressure gauges were replaced, and the pressure difference was still the same. At this time, it was suspected that the hair seal head gasket might be damaged.
Due to the damage of the refrigerant inlet side and the outlet pipe end head gasket, the refrigerant portion R11 is short-circuited, the flow resistance is reduced, the flow rate is decreased, the flow rate of the refrigerant R11 is slowed, and the flow rate of the refrigerant R11 is compared with the evaporator. The heat transfer coefficient is closely related. For the same evaporator and brine, only the flow rate changes and the heat transfer coefficient changes. If the head gasket is damaged, the two processes will not pass completely, the cooling capacity of the unit will drop, and the cooling will be slow.
3. Measures to close the evaporator coolant inlet and outlet valves, open the drain valve of the head coolant R11, and place the coolant R11 from the evaporator into the R11 barrel. After the release, remove the ends of the two ends and find that one end of the head gasket is damaged. The pad debris in the pipe was blown off with nitrogen. The gasket is made of 2mm thick asbestos board, the head is sealed, the leak is tested, and there is no leakage at the head.
The evaporator is vacuumed on the side of the refrigerant, the moisture in the tube is removed, the inlet and outlet valves of the brine are opened, and the operation is started. The unit is cooled normally, and the temperature is lowered by about 15~20 °C per hour.
Incidentally, for dry evaporators, if the sealing position of the head is damaged, it will cause liquid shock and compressor frost.
First, the oil level of the oil separator is falling too fast
1. The phenomenon of failure starts the test of the cryogenic unit, and the technical data of the R22 high temperature car and the R13 low temperature car are normal, and the system has a good cooling effect. However, after the shutdown, the oil level of the oil separator was reduced by about 10 mm through the oil sight glass. Turn it on again, stop after running for a while, and the oil level drops by about 10mm.
2. Cause Analysis The oil may leak. The oil and gas separator, the oil cooler, the essential oil filter and its pipeline were inspected, and no oil leakage was found, indicating that the system had no external leakage.
The oil may leak inside. The oil cooler is a shell-and-tube heat exchanger, which circulates water to the tube and deep-cools the oil to the shell. The tube and the expansion joint may leak, check the oil cooler tube. First, open the circulating water drain valve at the head and put the circulating water into a clean basin. No oil traces were found in the circulating water. It is preliminarily determined that the oil cooler does not leak.
Close the oil cooler circulating water inlet and outlet valves, remove the oil cooler at both ends, and the oil cooler oil pressure gauge pressure is 0.8Mpa, which is the pressure of the R13 system. The oil cooler was leak-tested, and one end of the tube was plugged with rubber, and the other end was inspected with soapy water one by one. No oil leakage was observed. When the oil cooler is working normally, the pressure can reach 1.5 MPa. To this end, the oil cooler is gradually pressurized to 1.5 MPa with nitrogen. After inspection, there was no leakage.
The oil may enter the R13 system, slightly open the full-liquid evaporator drain valve and find that there is indeed oil in it. Possible reasons are: the unit is overloaded too fast, causing the unit to run oil; the oil separator is not good in oil separation; the heat load is too low, causing the evaporation temperature to be too low; the suction expansion valve is too large; the cooling water is too large to open, condensation The temperature is too low.
Re-open the unit and slowly increase the load to make the unit operate normally. Careful observation of the oil level of the oil and gas separator mirror, found that the unit did not drop in the operation of the oil, indicating that the above reasons can not cause oil. However, after stopping, the oil level dropped by about 10 mm and the compressor was found to be reversed. Indicates that the suction check valve is not closed tightly or the solenoid valve is malfunctioning. After inspection, the solenoid valve is intact.
The suction check valve and the exhaust line are controlled by a solenoid valve. During normal operation, the solenoid valve is closed, and the suction check valve is opened by the suction pressure to supply air normally. When parking, the solenoid valve opens, the exhaust pressure collides with the suction check valve, and is exhausted by high pressure. Close the suction check valve to prevent the compressor from turning up.
The compressor has reversed, indicating that the suction check valve is not closed tightly. The oil and R13 gas flow backward from the high pressure part of the oil separator to the suction line and the low pressure part of the evaporator, causing the oil level of the oil separator to drop and run oil.
3. Solution When the device is in normal operation, it can be adjusted to the automatic running state. When parking, first reduce the load of the low temperature car to 5%, then manually close the suction valve, press the parking button after the Zui, the device can stop running. With this method, the oil level is no longer lowered, that is, the lubricating oil does not enter the R13 system.
Second, the cooling capacity has dropped significantly
Fault phenomenon
Technical data of R22 high temperature car: suction pressure 0.21Mpa, suction temperature -25°C, exhaust pressure 1.39Mpa, exhaust temperature 71°C, oil pressure 1.37Mpa, oil temperature 47°C, compression ratio 3.5, load 100%, percentage The current is 100%, the oil filter pressure difference is 0, and the oil level is normal.
R13 low temperature car technical data: suction pressure 0.13 Mpa, suction temperature -47 ° C, exhaust pressure 1.37 Mpa, exhaust temperature 72 ° C, oil pressure 1.35 Mpa, oil temperature 55 ° C, compression ratio 3.4 load 100%, percentage current 100%, oil filter pressure difference 62Pa, oil level is normal.
The unit is operated according to the above parameters, and all parameters are normal, but the unit is slow in cooling, and the temperature is reduced by 7~8 °C per hour.
2. Analysis of the causes The temperature monitoring instrument of the cryogenic vehicle was carefully observed. It was found that the outlet temperature of the refrigerant R11 was only -31 °C, which was very different from the suction temperature of the low temperature vehicle -47 °C, and the outlet temperature of R11 should be -57 °C. The evaporator heat exchange is not good. And the refrigerant pressure gauge of the evaporator shows an inlet pressure of 0.33 MPa and an outlet pressure of 0.3 MPa. The normal inlet and outlet pressure difference should be 0.05Mpa, the actual pressure difference is only 0.03Mpa, and the pressure difference is small. The inlet and outlet pressure gauges were replaced, and the pressure difference was still the same. At this time, it was suspected that the hair seal head gasket might be damaged.
Due to the damage of the refrigerant inlet side and the outlet pipe end head gasket, the refrigerant portion R11 is short-circuited, the flow resistance is reduced, the flow rate is decreased, the flow rate of the refrigerant R11 is slowed, and the flow rate of the refrigerant R11 is compared with the evaporator. The heat transfer coefficient is closely related. For the same evaporator and brine, only the flow rate changes and the heat transfer coefficient changes. If the head gasket is damaged, the two processes will not pass completely, the cooling capacity of the unit will drop, and the cooling will be slow.
3. Measures to close the evaporator coolant inlet and outlet valves, open the drain valve of the head coolant R11, and place the coolant R11 from the evaporator into the R11 barrel. After the release, remove the ends of the two ends and find that one end of the head gasket is damaged. The pad debris in the pipe was blown off with nitrogen. The gasket is made of 2mm thick asbestos board, the head is sealed, the leak is tested, and there is no leakage at the head.
The evaporator is vacuumed on the side of the refrigerant, the moisture in the tube is removed, the inlet and outlet valves of the brine are opened, and the operation is started. The unit is cooled normally, and the temperature is lowered by about 15~20 °C per hour.
Incidentally, for dry evaporators, if the sealing position of the head is damaged, it will cause liquid shock and compressor frost.
Natural pigment supplier Organic Herb Inc's range of products include: Marigold Extract (lutein, yellow pigment), Sorghum biocolor extract (Sorghum pigment, red), beetroot extract (Beet Red), Ginger extract (gingerol yellow), Black Carrot Extract (red), Purple Kale pigment(red cabbage pigment), Purple Sweet Potato Color, chili extract (capsicum red pigment), Gardenia Extract (Gardenia Yellow) etc, these Natural Colors can be widely used as food additives , beverage additives and dietary supplement etc.
Natural Pigments have grabbed a lot of attention as an alternative of synthetic pigments.The plant extracted color finds its application in a variety of fields, including pharmaceuticals drug production ,nutraceuticals,food production ,dairy, beverages, animal feed ,cosmic and the confectionery segment.Plant extract of natural colors is not only good for coloring but also good for improve wellness as most of them are antioxidants.Organic Herb Inc is a China-based plant extract manufacturing company which takes pride in providing a wide range of high quality environmentally friendly and water miscible pigments from organic plants at competitive market prices.
Natural Colors,Natural Pigments,Carrot Pigment,Gardenia Extract Powder
Organic Herb Inc. , https://www.extracts.pl