Shell boilers may be defined as those boilers in which the heat transfer surfaces are all contained within a steel shell. Shell boilers may also be referred to as "fire tube" or "smoke tube" boilers because the products of combustion pass through the boiler tubes, which in turn transfer heat to the surrounding boiler water.
The efficiency of a coal-fired boiler depends on the loss of the boiler, the best efficiency in the boiler can be achieved if the losses are kept to the minimum. Since 50% of the losses are dependent on the fuel and ambient condition, the best efficiency can be achieved by properly tuning the other 50%, i.e. mainly carbon loss and dry gas loss.
The quality of the water used to produce the steam in the boiler will have a profound effect on meeting the objectives such as safe operation, maximum combustion and heat transfer efficiency, minimum maintenance and long working life.
If the hot oil pump of the fully automatic thermal oil heater is suddenly damaged and stops working during the operation, the boiler circulation will be blocked. If the fuel is still burning to make the oil temperature keep rising, it will cause the coking of the hot medium oil which is easy to cause a fire. If the fully automatic thermal oil heater catches fire due to the power cut during the operation, the boiler operator should quickly put out the fire in the furnace to stop the fuel from burning, and blow a large amount of cold air into the furnace to lower the temperature.
The flue gas first enters the cyclone dust collector which acts as a primary dust collector to make the large dust particles in the flue gas settle down. The cyclone dust collector is a dust removal device which uses the centrifugal force generated by the cyclone flow to separate the dust particles from the air flow. Afterwards, the flue gas enters the wet scrubber dust collector which is a circular-type cylinder. The circulating water enters the dust collector from the upper overflow tank to form a uniform water film on the inner wall of the dust collector. The flue gas is induced tangentially or spirally from the lower part of the cylinder and rotates in the cylinder. Under the influence of the centrifugal force, the dust particles are separated from the flue gas and then the flue gas is also spirally led out from the top of the cylinder. The dust particles are thrown to the water film, transferred to the bottom and finally discharged from the dust port.
The thermal oil heater, also called the organic heat carrier boiler, is a kind of once-through boiler developed based on the forced circulation design concept. With gas, oil or coal as the fuel and heat conducting oil as the medium, the thermal oil heater adopts the thermal oil pump to force the medium conducting the circulation in the liquid phase. The medium transfers the heat energy to the heating equipment and then returns to the furnace for being reheated. The thermal oil heater has the advantages of high-temperature and low-pressure heating and precise control of the medium.
The biomass-fired steam boiler is used widely and the biomass belongs to the renewable energy with high thermal efficiency which can be applied by many production enterprises.
