Follow this annual maintenance guideline and keep doing it, you will find that the RX gas generator runs stably and smoothly for years, it is definitely worth trying.
1. General Inspection
All safety devices must be inspected at least once a year, such as overtemperature protection in heating room, flame check valve protection, exhaust port safety protection, overload protection, short circuit protection, cooling water pressure protection, propane pressure protection, air blower pressure protection and so on.
2. Maintain Electrical Par
- Electrical equipment can go aging or being less reliable over time, so the status of electrical components in both distribution cabinet and furnace body must be checked one by one every year; Measure blow winding resistance with a multimeter, and then its insulation resistance with a 500V Megohmmeter; check whether Relays and buttons contacts are in good contact with multimeter.
- Bolts on electrical components of distribution cabinet and furnace body may over time. Therefore, inspect and tighten bolts on all electrical components one by one every year to prevent from bad contacts.
- Overtemperature protection function should be tested and confirmed every year. Take following steps: set the overtemperature value manually. When the actual temperature is higher than setting, safety contactor should be disconnected. At the same time, the touch screen shows the alarm of overtemperature in the heating room; otherwise, the safety contactor should be connected. At last press failure reset button to reset the heating room warning on touch screen.
- Pull the thermocouple out of the furnace, check its appearance, and then reconnect the compensating wire on the thermocouple; manually set the threshold on the temperature control, when the setting is greater than the actual, the instrument outputs the heating signal, otherwise, the instrument cuts off the heating Signal.
- With all safety concerns under control, manually force start power components (heaters and blowers), and measure its circuit current with clamp ammeter. The current for heaters should be close to its rated current, and that of blower should not exceed its rated current.
- Check the on-off reliability of all motor protection switches with multimeter, and then determine and adjust the setting current according to electrical drawings.
- Check all pressure switches with multimeter. When actual pressure is greater than setting value, pressure switch acts; otherwise, the pressure switch is reset; after the test, the pressure switch must be adjusted to the correct set value.
- If power supply voltage is too low, some electrical components may not work, on the other way, some electrical components may be burned out, power supply voltage directly affects the stability, so it is necessary to check the power supply voltage every year by with multimeter, all three-phase voltage should be around 380V (+5%).
3. Check Casing structure
- Check every welding seam on the furnace shell to ensure that all welds are in good condition and there is no cracking.
- Visually inspect other parts of the furnace shell for obvious external damages.
4. Check Cooling System
- Working temperature of front cooler is relatively high, once the cooling water supply stops, the cooling water coil on the front cooler is liable to be damaged. Therefore, during the annual maintenance period, the cooling water coil on the front cooler must be carefully inspected and replaced immediately if damaged.
Further, the sealing ropes between the front cooler and reaction tank will be aged due to high temperature. Remove old sealing rope and replace with new one.
- If dew point is unstable, RX gas tends to create condensate or carbon deposit on post-cooler. Therefore, carefully check the post-cooler tubel use tools to clean them up, and if necessary, rinse the tube with water. After rinsing, clean the tube by compressed.
In addition, the sealing rings between the rear cooler and the front cooler and RX gas output pipeline have aged and replace them during maintenance.
5. Check Heating Chamber
- After a year, the thermal insulation layer under heating chamber roof may fall off. Remove all heaters, reaction tanks and thermocouples, remove the roof, check whether the thermal insulation layer under the roof is in good condition, replace damaged fixing pins and repair shattered linen.
- There will be some dust and debris at the bottom of the heating chamber, clean them with vacuum cleaner.
- At room temperature, there will be a contraction joints on top of lining in the heating. If its width is less than 10 mm, it’s good, and fill the seam the ceramic fiber blanket; if the lining has large cracks, and the bricks around it might fall, repair the bricks immediately.
6. Reaction Tank
- Reaction tank is an important component of generator, thus also the most important part of the annual maintenance. Reaction tanks need to be removed from the heating chamber. Carefully inspect its shell and all welds should be intact and intact. If there are bulges and cracks in the pipe body, it needs to be replaced.
- After a year, the diversion bricks and columns in the reaction tank may be damaged. Remove and inspect all diversion bricks, columns and catalyst in the reactor tank. replace damaged parts if they are cracking or damaged.
- Catalysts are working constantly in high temperature, they are easy to be powdered. Pour all the catalyst into a container, then clean up the powdered catalyst, re-use intact ones. After 2 years the dew point might fluctuates greatly, it is the time that the catalyst should be replaced during the annual maintenance period if there is no problem in removing the feed gas.
- According to the filling process of the reaction tank, the reaction tank should be placed vertically, and is gradually refilled from bottom to top.
- The blower fixes feed gas (air, propane or natural gas) in a certain proportion, and pump them into reactor tank, so the blower is basically running 24 X 7. Because of that, we need to pay special attention to it during annual maintenance. The main maintenance items are to check the blower's running status and sealing.
In order to confirm the status of blower, force start the blower and let the internal pressure reach a certain level. Therefore, open the intake pipe of the blower (to inhale air), seal the outlet and press the blower contactor to start it (forced start-up time should not exceed 1 minute), check if the blower runs smoothly and silently. If the blower is loud and vibrating, stop immediately for maintenance or replacement.
During the forced start of the blower, brush soap water along blower's duct, check for leakage, repair immediately if leakages found.
- confirm that three-phase resistance of the blower winding being the same with multimeter; after long-term operation of the blower, some bolts may be loosened, tighten bolts on the terminal of the junction box and the fastening nuts on the casing.
8. Heating system - squirrel cage heater
- To confirm the status of ammeters of heating circuit, the temperature controller is adjusted to manual mode under the condition of ensuring the safety of the heating circuit, and the instrument is forced to work at 100% output. Check heating ammeter with clamp ammeter, the display value of the two ammeters should be within the rated current of heating circuit (±5%). If it goes beyond this range, further check and deal with the issue.
- The flat cable may loosen due to thermal expansion and contraction over time, check and tighten the heater braid during the annual maintenance.
- Because of the high current in the heating circuit of the distribution cabinet, the terminals on some components are easy to be tightened for a long time, so these parts need to be inspected and tightened during the annual maintenance period.
- The thyristor rectifier, main power execution part, amplifies signals from temperature controller, and controls the current of the heating circuit. The thyristor emits a lot of heat, which will be taken away by radiator and cooling fan. After one year, there will be a lot of dust deposited on the radiator and cooling fan, clean up them and check the operation of cooling fan. replace the fan if it does not work smoothly.
After the maintenance of the thyristor, observe if its heating current output matches the output power of the temperature control instrument at the initial stage of heating. If the output current of the power regulator does not change with the instrument, further inspection is needed (if applicable).
- The heating wire and ceramic piece of heating elements may be damaged over time, but it’s not easy to see during operation time. Therefore, all heaters need to be pulled out from the furnace for inspection. If the heating wire is bent and deformed, or ceramic plates crack, replace heaters immediately.
- Overtemperature protection instrument triggers alarm when the actual temperature of the heating room exceeds designed range, ands cut off safety contactor in the heating circuit, so as to protect the generator. Set the overtemperature protection instrument to working temperature + 10℃
9. Gas supply and dew point control system
- After one year, the filters of air, natural gas and endothermic gas may be blocked. Therefore, check all filters during the annual maintenance period, and replace blocked filter immediately.
- After the end of annual maintenance, heated the generator to working temperature, check and confirm if all ball valves, balance valves, solenoid valves, electric valve, flame backstop and unloading valve are normal. Replace damaged parts immediately.
- After the generator starts to produce gas, calibrate dew point of RX gas with portable dew point meter, and check if the controlling air electric valve acts with dew point. If not, further checks and troubleshooting are needed.