In this paper, the self-controlled vertical autoclave is taken as an example to analyze the common faults in the vertical autoclave during use and to propose corresponding fault handling methods and preventive measures. Common faults include: failure of heating function, abnormal operation of water level device, failure of interlocking lamp, air leakage, abnormal operation of safety valve, failure to properly exhaust, drainage, etc.

(1) When the instrument is used, the heating function fails and steam cannot be generated normally. When the instrument is running, the heating indicator on the panel is on, but the temperature indication does not rise and it is kept at room temperature.

Solution: Open the side cover of the instrument, and the panel display normally indicates that the 220V power supply normally enters the control circuit. Remove the wire connected to the heating pipe and check the resistance of the heating pipe with a multimeter. The resistance is generally between 8 and 15 Ω. If the resistance is too large, the internal heating circuit is broken and must be replaced. Since the heating tube burns out for a reason, the solid state relay that controls the heating tube should be inspected regardless of whether the heating tube is good or bad in the first step. In the case of power-on, the relay input voltage should be around 12VDC, and the output voltage should be around 220VAC. If the input is normal and the output is abnormal, the relay must be replaced; if the input is abnormal, check the load output control section on the control circuit. The most common situation is the above two.

(2) When the instrument is used, the water level device works abnormally. When the instrument is turned on, the control circuit checks the water level. There are three indicators on the control panel: “high water level”, “low water level” and “water shortage”. When using normally, the water level should be kept at a high water level, that is, the “high water level” indicator light is on. If the water level light does not illuminate or the "water shortage" light is on and the alarm is given when sufficient water is added, the water level device is working abnormally. Treatment method: open the side cover of the instrument, first check whether the connection between the water level device and the control circuit is loose; use a wrench to unscrew the screw cap on the water level device, take out the water level device, check whether the three probes are rusty, and remove the rust with alcohol cotton. deal with. In the case of power-on, the three probes are sequentially short-circuited with the outer steel pipe of the water level device to check whether the water level indicator of the control panel works normally. If it is normal, the water level device is not damaged; otherwise, the water level control circuit on the control circuit must be checked; after the processing is completed, the water level device is installed, the power is turned on, and the water is checked to check the indicator light. Generally, the work is abnormal due to poor contact of the water leveler or rust on the surface of the probe.

(3) The interlock lamp does not light and the instrument does not heat normally. The interlocking lamp is connected to the control circuit by interlocking button, interlocking lever and interlocking controller at the upper cover of the instrument to play the interlocking protection function. When the cover of the instrument is closed, the interlock light does not illuminate to indicate that the control circuit has no signal input or circuit damage. Solution: Check the interlock switch and the control switch under the interlocking lever under normal condition when the cover of the instrument is closed. The normal control switch should be connected in series. If abnormal, the control switch must be replaced; check the interlock controller under the normal conditions of the above control switch. Adjust the controller knob to make the internal shrapnel contact closed, and the signal input to the control circuit; normally, due to the high temperature of the upper cover of the instrument, the interlock button switch below it is aged at high temperature, resulting in poor contact.

(4) The instrument leaks and the pressure cannot meet the requirements. Instrument leakage is common at the cover of the instrument. Damage to the sealant ring due to aging of the seal ring or rotation of the cover. Treatment method: remove and seal the sealing rubber ring, and treat the talc powder with less serious damage; replace it if it is aging or damaged seriously.

(5) The safety valve works abnormally, and the pressure is too high to relieve pressure. The safety valve is the last protective barrier of the autoclave. When the instrument works abnormally and continuously heats to make the pressure greater than 127MPa, it automatically jumps to relieve pressure, thus protecting the safety of the instrument and the operator. Treatment method: Manually open the safety valve pressure relief when the pressure is about 108MPa, to prevent the safety valve from rusting for a long time; when the damage is serious, it must be replaced and re-commissioned by professional maintenance personnel.

(6) The instrument cannot be properly vented and drained, resulting in a large difference between pressure and temperature, which cannot be properly sterilized. Generally, the bottom of the automatic self-control vertical autoclave has exhaust and discharge three-way valves. Failure to properly exhaust will result in high pressure indication and danger. Treatment method: open the side cover of the instrument, disassemble the drain pipe and the three-way valve to clear the rust; severely rust must be replaced, and periodically open the exhaust and drain valve impact pipeline during the use; in order to prevent this problem Reappear, add distilled water to the sterilizer as much as possible and replace it regularly (add distilled water normally twice a week; add tap water to be replaced once a day)

Emergency troubleshooting steps

(1) Check the pressure gauge first when the instrument is abnormally alarming. If the maximum pressure is exceeded and the safety valve does not jump, immediately turn off the power and rotate the exhaust valve to the maximum.

(2) Observe the working condition of the water level indicator. If there is water shortage, cut off the power supply and deflate until the pressure gauge indicates “0”, then open the upper cover, add water to the “high water level” indicator light and then turn on the power.

(3) If the pressure gauge indicates normal operation, observe the working condition of the interlock indicator light and the pressure indicator light. If abnormality should be recorded and reported. (4) If the temperature indication on the control panel is abnormal and the pressure gauge indicates normal, the exhaust valve knob should be adjusted to make it as uniform as possible. (5) If there is an unknown reason, the alarm should be cut off immediately and reported. At the same time, the upper cover must be opened to remove the sterilized items when the pressure gauge indicates “0”. Finally, the professional maintenance personnel should be notified for maintenance. 3 autoclave

Precautions when using

(1) After the sterilization is completed, wait until the pressure gauge indicates “0” and then open the upper cover. When the sterilization chamber is under pressure, the interlocking handle cannot be lifted and the door cannot be forcibly opened.

(2) Do not quickly relieve pressure when sterilizing liquid. The door can only be opened when the liquid temperature drops below 70 °C. Open the door immediately after sterilization is prohibited.

(3) The probe and water level gauge should be cleaned regularly.

(4) The steam inlet should not be blocked; the door frame and rubber ring are not damaged. It is best to apply talcum powder on the rubber strip after use every day to prolong the life of the rubber strip.

(5) The drain valve is cleaned once a month to facilitate cooling and maintaining temperature.

(6) After one year of use, a qualified system inspection should be conducted every year by a qualified inspection department.

(7) Can not rely entirely on automatic water level protection, should always pay attention to the water level, so as not to burn the electric heating tube.

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