What is the function of negative pressure boiler?

Boiler pressure is the main signal to indicate the combustion status and judge whether the combustion in the furnace is stable. Generally, it is divided into micro-positive pressure and negative pressure. What is the function of negative pressure boiler? What's the difference between a negative pressure boiler and a positive pressure boiler?

What is a negative pressure boiler?

The negative pressure boiler refers to the boiler equipment that keeps the furnace in a negative pressure state when sufficient air volume is met in the combustion process. The negative pressure here is relative to the atmospheric pressure. Generally, if the boiler pressure gauge shows negative, it is negative, and if it is regular, it is positive.

What is the function of negative pressure boiler?

What is the function of negative pressure boiler, that is, what advantages it has? During the operation of the boiler, when the pressure in the furnace becomes positive, the high-temperature flue gas and flame in the furnace will be sprayed out from some holes and imprecise places, which will not only affect the environmental hygiene and endanger personal safety, but also cause coking in the furnace and burner, deformation and damage of burner, steel beam and furnace wall due to overheating, as well as unstable and incomplete combustion, and reduce the thermal efficiency (except for the micro-positive pressure furnace). The function of negative pressure boiler is to provide suitable combustion conditions.

Positive pressure operation

The boiler with positive pressure operation has higher requirements for the tightness of the whole unit equipment, and there are usually sealed fans.

The advantage is that the air leakage ratio of the system is small, which is good for the combustion stability of the boiler and good for the economy. The disadvantage is that the equipment investment is relatively large, and the reliability requirements are relatively high. In addition, the environmental sanitation on site may not be very good. The positive pressure system is relatively complicated.

Negative pressure operation

When the negative-pressure unit is operated, the whole system and the boiler furnace will maintain a certain negative pressure because of the suction of the induced draft fan under normal circumstances. First, the auxiliary machine has a large amount of electricity and air leakage, which has a certain impact on the unit's economy and thermal efficiency.

No matter what function the negative pressure boiler has, the boiler should be designed from two aspects: economy and safety.