Catalytic Combustion Equipment Ignition Failure: What Are The Reasons? 6 Troubleshooting Directions

When operating RCO catalytic combustion equipment for VOCs waste gas treatment, ignition failure is one of the most frequent faults encountered by factory maintenance teams. The equipment cannot start normally, which directly interrupts waste gas treatment and affects the whole production schedule. Many operators repeatedly try to restart the machine without identifying the root cause, which may bring potential safety risks and further damage components. This article sorts out six core inspection directions to help you locate ignition failure step by step. Zhengzhou Puhua Technology is an environmental protection equipment manufacturer in Henan, focusing on the design, research, development and production of dust control equipment, desulfurization equipment, denitrification equipment, VOCs organic waste gas treatment equipment, pneumatic conveying equipment and wastewater treatment equipment. Its product portfolio includes baghouse dust collectors, RCO catalytic combustion equipment, RTO equipment, VOCs treatment equipment, desulfurization towers, denitrification equipment, photo-oxidation catalytic equipment, pulse dust collectors, mobile dust collectors, ultra-low emission equipment and wastewater treatment equipment. Understanding these common ignition faults can help operators maintain Puhua’s catalytic combustion systems stably and reduce unexpected shutdowns.

1. Ignition System Component Faults

The ignition system is the core part to provide ignition sparks. Damaged or contaminated accessories will directly lead to no spark output and ignition failure.

• Ignition electrode: surface covered with dust, oil and carbon deposits, electrode gap out of normal range, insulator cracking and short circuit.

• Ignition transformer: internal circuit aging, no high-voltage output, no spark between electrodes.

• Flame detector: lens covered with soot, signal deviation, the control system cannot receive flame feedback signal and trigger safety lock.

Inspection suggestion: Turn off the power and gas supply first. Clean the ignition electrode and flame detector lens, check the discharge spark, test the transformer output, and adjust the electrode gap according to the equipment manual. For RCO catalytic combustion equipment supplied by Zhengzhou Puhua Technology, the maintenance manual contains standard parameters of ignition components for daily inspection reference.

2. Fuel Supply Abnormality

Unstable fuel supply is another common cause of ignition failure. Too high or too low gas pressure will break the normal air-fuel matching condition.

• Gas solenoid valve failure: valve stuck, coil damage, unable to open and deliver fuel when receiving ignition signal.

• Gas pressure anomaly: pressure lower than the minimum starting threshold or exceeding the upper limit, failing to form stable combustible mixed gas.

• Gas pipeline blockage: impurities accumulated in pipeline and filter, cutting off fuel supply.

Inspection suggestion: Check the gas pipeline switch and filter, test the opening action of solenoid valve, monitor real-time gas pressure, and adjust the pressure regulating valve. Before each startup, operators should complete pipeline pre-inspection to avoid ignition lockout caused by fuel supply problems.

3. Control System and Safety Interlock Protection

Catalytic combustion equipment is equipped with multiple safety interlock programs. If any pre-start condition fails, the PLC control system will automatically stop the ignition sequence.

• Emergency stop button reset incompletely: emergency circuit remains disconnected.

• Pre-purge not completed: the system fails to finish the replacement of residual waste gas inside the furnace, and the ignition program is locked.

• Temperature sensor signal error: thermocouple damage or signal drift, leading the system to misjudge furnace temperature and refuse ignition.

• Fan interlock fault: circulating fan does not run normally, interlock condition is not satisfied.

Inspection suggestion: Check the status of emergency stop button, fan operation signal, thermocouple wiring and pre-purge record. Read the fault code on the control panel and troubleshoot interlock items one by one. Zhengzhou Puhua Technology designs safety interlock logic for its RCO catalytic combustion equipment to prevent unsafe ignition operation, and the control panel can display corresponding fault prompts for quick diagnosis.

4. Catalyst Performance Degradation

Catalyst is the key medium for catalytic combustion reaction. When the catalyst loses activity, the waste gas cannot complete low-temperature catalytic oxidation even if ignition succeeds, and the equipment will report flame failure or shut down automatically.

• Catalyst poisoning: sulfur, chlorine, heavy metal substances in waste gas cover the active sites of catalyst.

• Catalyst coking and blockage: particulate matter and viscous organic matter deposit on catalyst surface.

• Catalyst aging: long-term high temperature operation leads to sintering of active components, and the light-off temperature rises obviously.

Inspection suggestion: Check the pressure difference before and after the catalyst module, observe the surface of catalyst carrier, test the actual light-off temperature of the equipment. When catalyst activity drops obviously, cleaning or replacement can be arranged. Zhengzhou Puhua Technology selects suitable catalyst configurations according to customers’ waste gas components when customizing VOCs treatment equipment, to reduce the risk of catalyst poisoning and failure in actual operation.

5. Waste Gas Concentration and Airflow Instability

Stable VOCs concentration and airflow are basic conditions for continuous catalytic combustion. Too low waste gas concentration cannot maintain heat accumulation after ignition, resulting in flameout immediately after ignition.

• VOCs concentration below the minimum reaction threshold, unable to sustain catalytic combustion heat release.

• Excessive airflow velocity: the mixed gas passes through the catalyst chamber too fast, heat cannot accumulate.

• Air leakage in pipeline: external cold air enters the furnace, reduces furnace temperature and dilutes waste gas concentration.

Inspection suggestion: Monitor online VOCs concentration value, check pipeline air leakage points, adjust fan frequency and intake air volume. Before formal feeding, the equipment should run empty to stabilize furnace temperature.

6. Air-fuel Ratio and Combustion Air Distribution Problems

Unreasonable matching of combustion supporting air and fuel will form non-combustible mixed gas, and the spark cannot ignite the mixture.

• Damper adjustment error: excessive or insufficient combustion air.

• Blocked air duct: dust accumulation blocks the air channel, and the air supply is insufficient.

• Uneven mixing of fuel and air: local fuel-rich or fuel-poor area inside the furnace.

Inspection suggestion: Check the air duct and air damper, clean the blockages, calibrate air-fuel ratio parameters. Do not adjust the damper blindly during ignition test, to avoid safety risks.

Comparison Table of Ignition Fault Phenomenon and Preliminary Judgment

Safe Operation Tips For Catalytic Combustion Equipment Troubleshooting

1. Cut off gas supply and power supply before disassembly and inspection, and wait for the furnace body to cool down.

2. Do not repeatedly trigger ignition operation continuously when ignition failure occurs, to prevent combustible gas accumulation inside the furnace.

3. Carry out ventilation and purging treatment before entering the furnace for inspection.

4. For complex electrical and control system faults, contact professional technical personnel instead of modifying the control program privately.

Zhengzhou Puhua Technology provides after-sales technical guidance for RCO catalytic combustion equipment, RTO equipment and VOCs waste gas treatment systems. The company’s environmental protection equipment covers the whole set of solutions from dust removal to waste gas and wastewater treatment. Proper routine maintenance can effectively reduce ignition failure and extend the service life of catalytic combustion equipment. If you cannot locate the fault after completing the six directions of inspection, you can seek professional technical support for equipment inspection and maintenance.

Final Summary

Catalytic combustion equipment ignition failure is usually caused by one or more factors among ignition components, fuel supply, control interlock, catalyst status, waste gas condition and air-fuel matching. Operators should follow safe operation procedures to check item by item according to the above six troubleshooting directions. Regular maintenance of key components can greatly reduce the probability of startup failure. As a professional manufacturer of VOCs treatment equipment, Zhengzhou Puhua Technology focuses on stable equipment design and complete supporting technical services, helping industrial users complete organic waste gas treatment safely and efficiently.