Do you know the common fault solutions for these vacuum freeze dryers?
With the development of freeze-drying technology, vacuum freeze dryers are widely used in the fields of biology, medicine, and preparation of nanomaterials. Due to the working characteristics of the vacuum freeze dryer, vacuum freeze dryers often work beyond their limits, which leads to some failures in the refrigeration system as the core component of the vacuum freeze dryer. Most of the refrigerators are Compressor, evaporator, condenser, expansion valve, gas-liquid separator, oil separator, etc. It is easy to cause failures for the refrigerator, so it is necessary to understand some common faults, and to master the solutions to these faults, and to understand the daily maintenance and maintenance of the vacuum freeze dryer refrigeration system. In order to reduce the occurrence of the refrigeration system of the vacuum freeze dryer, this paper starts from the common problems of the vacuum freeze dryer refrigeration system, and makes a detailed analysis of the relevant solutions, and does the daily maintenance and maintenance of the vacuum freeze dryer refrigeration system. First summary.
Vacuum freeze dryer refrigeration system several common faults are: high pressure alarm, compressor motor overload, motor temperature is too high, oil pressure difference alarm, water pressure alarm and expansion valve adjustment effect, the following Analyze the causes of these faults and related solutions.
The causes of the six faults and their solutions are as follows:
(1) For the occurrence of high-pressure alarm, the reasons are as follows: the water in the water condenser is insufficient or the water temperature is too high; some scale is formed inside the water condenser, so that the heat conversion efficiency is reduced; the compressor is working. At the time, the low-pressure pipeline broke, causing air to enter the refrigeration pipeline; the valve of the refrigeration pipeline was not fully opened, or the exhaust pipe was blocked, causing poor exhaust; the use of the refrigerator caused too much pressure on the exhaust.
The solution is as follows: reduce the water temperature or increase the flow rate; clean the lower water condenser; make the refrigeration pipeline to be simple. If the operation cannot be performed in the working state, the shut-off valve above the water condenser can be opened first, and the water condenser can be opened. The air is released a part; it is necessary to open the valve on the compressor pipe to the large size; a part of the refrigerator needs to be discharged.
(2) For the occurrence of motor overload of the compressor, the reason may be: there is debris in the piston cylinder, so that the piston is not smooth, the situation of holding the shaft and closing the cylinder occurs; the thermal load of the compressor is overloaded, the reason may be Caused by steam sterilization and other operations; thermal overload relays did not reset in time.
The solution is to clean the internal residual of the compressor in time; the cooling compressor reaches the allowable temperature in time; the relay is reset in time.
(3) For the occurrence of excessive temperature of the motor, the reason may be that the refrigerator is insufficient in return air, causing the motor not to be sufficiently cooled; the refrigerator is insufficient or lacking; the three-phase power supply of the compressor is unstable; There was a problem with the thermal protection module of the machine; the pipeline for the liquid supply was blocked.
The solution is to restart the switch of the compressor; replenish the refrigerant in time; provide the power supply of the compressor as required; and clear the blocked part in time; if necessary, replace the template.
(4) For the alarm condition of oil pressure difference, the reason may be that the relay with the oil pressure difference is not reset in time; if the freezing oil appears yellow or black, the freezing oil may deteriorate, causing the filter to be blocked; That is, there is a problem with the returning oil, so that the amount of oil in the crankcase of the compressor is not reached, and the oil pump cannot absorb the oil.
The solution is to perform a manual reset; clean the filter and replace the oil; tap the oil separator with a hard object and replace the separator if it does not work.
(5) For the alarm condition of water pressure, the reason may be that the supply of cooling water is insufficient; or the relay of water pressure has failed.
The solution is to increase the external water supply pressure; check the pressure relay.
(6) For the failure of the expansion valve adjustment, the reason may be that the internal adjustment gear is biased due to long-term force; the expansion valve is clogged, causing the pressure of the low pressure gauge of the compressor to be too low.
The solution is to strike the teeth so that the teeth are parallel to the inner plane; disassemble the expansion and clean it; check the pipe and filter or valve open.