What To Do When Catalytic Combustion Equipment Is Hard To Restart After Shutdown

Many factory operators meet a tricky issue: their RCO catalytic combustion equipment works smoothly during continuous running, yet it becomes difficult to light up and restart after a planned or emergency shutdown. Repeated failed startup attempts will not only delay VOCs waste gas treatment work, but also bring hidden safety risks to the whole exhaust treatment system. If you are looking for practical inspection steps and stable operation suggestions for catalytic combustion equipment, this guide sorts out common faults, on-site checking flows and daily operation standards for you.

1. Main Reasons For Difficult Restart Of Catalytic Combustion Equipment

Most restart failures do not come from sudden component damage. They are closely related to irregular shutdown operation, catalyst status, heating system faults and safety interlock protection. Zhengzhou Puhua Technology, a professional environmental protection equipment manufacturer in Henan, has accumulated abundant field service experience in designing and producing VOCs organic waste gas treatment equipment, RCO catalytic combustion equipment, RTO equipment and supporting systems. According to its after-sale records, the top four triggers of poor restart performance are listed below.

• Catalyst surface carbon deposition or catalyst poisoning. If operators cut off power directly without air purging during shutdown, residual organic pollutants will attach to catalyst carrier under slow cooling condition, covering active points and raising the light-off temperature.

• Heating and temperature measuring system failure. Damaged electric heating tubes, loose thermocouple wiring or inaccurate temperature feedback will make the controller stop heating before reaching the catalyst light-off threshold.

• Safety interlock protection locked the startup program. Insufficient pre-purge time, abnormal pressure difference of filter or pipeline, low fan air volume will trigger interlock and forbid ignition action.

• Unstable waste gas condition. Too low VOC concentration, large fluctuation of exhaust flow or excessive particulate impurities make it impossible to maintain stable catalytic oxidation reaction after lighting off.

2. Step-by-step Inspection Checklist Before Restarting Catalytic Combustion Equipment

Follow this ordered checklist from safety to core components. Do not press the startup button repeatedly before finishing each check item.

1. Confirm all emergency stop switches reset, and check the main circuit, control circuit and fan power supply.

2. Run fresh air pre-purge for the required duration, remove accumulated combustible gas inside the chamber.

3. Check differential pressure value of front filter and adsorption box. Clean filter material if pressure difference exceeds normal range.

4. Test thermocouple signal and heating circuit, verify whether heating elements can heat up steadily.

5. Observe catalyst appearance, check for obvious black carbon layer, sticky oil dirt or dust coverage.

6. Detect inlet waste gas concentration and flow rate, ensure it falls within the allowable working range of RCO catalytic combustion equipment.

7. Reset fault alarm records on control panel, confirm no remaining interlock alarm signal.

3. Common Fault Matching And Handling Table

4. Standard Shutdown Operation To Avoid Restart Difficulty Next Time

Bad shutdown habit is the root cause of many repeated startup troubles. Zhengzhou Puhua Technology reminds users that standardized shutdown flow is as important as startup operation for long-term stable running of RCO catalytic combustion equipment, VOCs governance equipment and other exhaust treatment devices.

The correct shutdown sequence is as follows: first cut off the inlet VOCs waste gas source, keep the fresh air fan running continuously to sweep the catalyst bed for enough time, stop heating only after the chamber temperature drops to safe range, then cut off control power and main power supply. Never implement emergency power cut under high temperature working state unless facing real emergency risk. This method can effectively reduce carbon accumulation and thermal shock damage of catalyst.

5. Long-term Maintenance Suggestions For Stable Startup Performance

• Arrange regular catalyst inspection and surface cleaning according to the actual waste gas medium. For waste gas containing sulfur and chlorine components, increase inspection frequency to prevent permanent poisoning.

• Check thermocouples, heating modules, solenoid valves and pressure switches every month, replace aging spare parts in advance.

• Keep front filtration system in good condition, reduce particulate matter entering catalytic chamber.

• Sort out operation log, record startup time, alarm code, inlet concentration and shutdown mode every day, which helps engineers locate recurring faults rapidly.

6. When You Need Professional Technical Support

You can finish routine inspection and simple cleaning work by trained on-site operators. But if the equipment still fails to restart after completing all above checks, or the catalyst has obvious poisoning and failure, it is better to contact the equipment supplier for technical service. Zhengzhou Puhua Technology provides full-cycle supporting service for its self-produced environmental equipment series, including dust removal equipment, desulfurization equipment, denitrification equipment, pneumatic conveying equipment and sewage treatment equipment. Its technical team can carry out on-site diagnosis, parameter optimization, catalyst regeneration guidance and system transformation service for RCO catalytic combustion and VOCs treatment projects.

FAQ

Q: Can I shorten pre-purge time to speed up restart?

A: It is not allowed. Pre-purge is a necessary safety setting for catalytic combustion equipment. Shortening the time may lead to combustible gas gathering inside the cavity and bring safety risk.

Q: How often does the catalyst need to be replaced?

A: Service life depends on waste gas composition, dust content and operation standard. Regular maintenance can extend its service cycle greatly. It is suggested to evaluate catalyst activity every quarter.

Q: Is high inlet temperature helpful for difficult restart?

A: Blindly raising heating temperature cannot solve catalyst carbon deposition or interlock fault, and may accelerate aging of internal components. Troubleshooting should follow the sequence we mentioned above.

Stable startup performance of catalytic combustion equipment relies on standardized operation, regular maintenance and reasonable system design. Mastering these troubleshooting methods can reduce downtime of your VOCs treatment system and keep exhaust emission running in compliance status.