Waste Heat Boiler Usage Tips

Waste heat boiler is a type of equipment that uses waste heat from exhaust gas, waste or waste liquid generated in industrial processes to produce hot water or steam, which is widely used in steel, cement, glass, chemical, electric power and other industries.

Preparation before running
Comprehensive inspection: confirm that the furnace body, flue, manhole, and hand hole are intact; Safety valves, water level gauges, pressure gauges and other accessories are complete and qualified.

Water quality standards: The feed water must meet the water quality standards of industrial boilers (e.g., turbidity ≤ 2.0 FTU, hardness ≤ 0.030 mmol/L, pH 8.0–9.5, dissolved oxygen ≤ 0.1 mg/L).

Water supply specifications: water supply time is not less than 2 hours in summer and not less than 3 hours in winter; The water temperature should be controlled at 10–50°C (winter) or 102–108°C (deoxygenated water).

Start and boost operation
Slow heating: When the flue gas inlet temperature rises above 200°C, gradually open the flue gas baffle; The heating rate is recommended to be ≤ 10°C/min to avoid thermal stress damage.

Phased boost :
0.1–0.2 MPa: close the exhaust valve and flush the water level gauge;

0.3 MPa: Discharge once, hot tighten flange bolts;
0.8 MPa: warm main steam pipe;

1.0 MPa or more: Turn on continuous sewage discharge and conduct steam sampling analysis.

Steam merging operation: steam merging can only be done when the steam pressure is slightly lower than the mother pipe pressure (0.05–0.1 MPa), the steam temperature ≥ 400 °C and the water quality is qualified.

Critical control points in operation
Water level stability: keep the water level of the drum within ±50 mm to avoid full water or lack of water.

Continuous sewage discharge: The bottom of the boiler barrel maintains an appropriate opening and adjusts according to the steam load to reduce the risk of salt concentration.

Regular cleaning: clean the heating surface every 10 days of operation or when the inlet and outlet resistance exceeds the standard; Small boilers can be purged with steam/compressed air, and large boilers should be cleaned with ultrasonic or gas blast.

Monitoring parameters: real-time monitoring of smoke temperature, steam pressure, water level, induced fan vibration, etc., and immediately stop the furnace for investigation of abnormalities