The supporting equipment and systems of steam boilers are the key to ensuring their safe, stable and efficient operation. According to their functions, they can be classified into three major categories: main supporting equipment, safety protection equipment and auxiliary system equipment.
Main Supporting Equipment: This type of equipment directly participates in the generation and transportation of steam and is a core accessory for the operation of boilers.
1. Water supply equipment
Feed water pump: It is responsible for transporting the treated water to the boiler drum and is the core equipment for maintaining the water level of the boiler. Common types include electric feed water pumps and steam-driven feed water pumps.
Water treatment equipment: including water softeners, reverse osmosis devices, etc. Steam boilers have extremely high requirements for water quality. Calcium and magnesium ions in untreated water can form scale, corrode the boiler body and reduce thermal efficiency. Deaerators can remove oxygen from the water and prevent oxidation and corrosion inside the boiler.
2. Combustion equipment
The supporting equipment varies depending on the type of fuel
Coal-fired boilers: Equipped with coal feeders, ash removers, coal mills (for pulverized coal furnaces), grates, etc., they are responsible for fuel transportation, grinding, combustion and ash and slag discharge.
Oil/gas boilers: Equipped with burners, fuel pumps/storage tanks/gas pipelines, etc., to ensure stable fuel supply and complete combustion.
Biomass boiler: equipped with conveyors, silos, etc.
3. Steam conveying equipment
Steam distribution cylinder: It distributes the steam generated by the boiler to different steam-using pipelines, and at the same time serves to stabilize pressure and separate steam and water.
Steam pipes and valves: including globe valves, gate valves, check valves, etc., are used for the transportation, regulation and shut-off of steam.
Safety Protection Equipment: This type of equipment is an essential device to prevent accidents such as overpressure, over-temperature, and water shortage in boilers, and must comply with national safety regulations for special equipment.
Pressure safety device
Safety valve: It automatically opens to relieve pressure when the boiler pressure exceeds the rated value. It is the most crucial safety component of the boiler and needs to be calibrated regularly.
Pressure gauge: It can display the pressure values of the boiler drum, steam distribution cylinder and other parts in real time, facilitating the monitoring by operators.
Pressure controller: Automatically controls the start and stop of the combustion system through pressure signals to prevent overpressure operation.
Water level safety device
Water level gauge: It visually displays the water level height in the boiler drum. Common types include glass plate water level gauge and magnetic flap water level gauge.
Water level alarm: When the water level is too high (full water) or too low (lack of water), it automatically issues an audible and visual alarm signal.
High and low water level interlock protection device: When the water level is abnormal, it automatically cuts off the fuel supply and combustion system, forcing the furnace to shut down.
Auxiliary System Equipment: This type of equipment is used to enhance the operational efficiency of boilers, reduce energy consumption and decrease pollutant emissions.
Flue gas treatment equipment
Dust collectors: Remove dust from flue gas. Common types include bag filters, electrostatic precipitators, and cyclone filters.
Desulfurization and denitrification equipment: For coal-fired and oil-fired boilers, it reduces the content of sulfur dioxide and nitrogen oxides in flue gas to meet environmental protection emission standards.
Induced draft fan and blower: The induced draft fan is responsible for discharging the flue gas after combustion, while the blower supplies combustion-supporting air to the furnace. The two work together to maintain a stable negative pressure in the furnace.
Waste heat recovery equipment
Economizer: Utilizing the residual heat of flue gas to heat the boiler feed water, it reduces the flue gas temperature and enhances thermal efficiency.
Air preheater: Utilizing the residual heat of flue gas to heat the combustion-supporting air and improve combustion conditions.
Waste heat boiler: Some industrial scenarios are equipped with waste heat boilers to recover the waste heat from other equipment and generate steam.
Control system
PLC control cabinet: It automatically controls and remotely monitors parameters such as water level, pressure, temperature and combustion of the boiler, achieving intelligent operation.