A fire tube steam boiler is a boiler where the combustion gases from the burner are channeled through tubes that are surrounded by the fluid to be heated. The boiler body is the pressure vessel and contains the fluid. In most cases, this fluid is water that will circulate for heating purposes or become steam for use in processing.
Each set of tubes through which the combustion gas passes, before making a turn, is considered a "step". Consequently, a three-step boiler will have three sets of pipes with the outlet located at the rear of the boiler.
In a water tube steam boiler, unlike a fire tube, water circulates inside the tubes. The heat that is generated and the combustion gases that surround the tubes heat the water that circulates inside them. Many water-tube boilers operate according to the principle of natural water circulation.
The capacity of this type of boiler can be enhanced by increasing the number of tubes in the boiler.
The primary objective of an industrial boiler is the generation of steam. Steam is generated by heat transfer at a constant pressure. The fluid, which is initially in a liquid state, is heated, produces a variation in its phase and becomes saturated vapour.
This saturated steam can then be used for different applications such as sterilization, fluid heating or electricity generation.
Steam boilers with a low NOx system are specially designed to minimize the environmental impact with the production of dry saturated steam. This type of boiler incorporates a stainless steel economizer with a cross flow integrated within the boiler and that, consequently, allows to reach maximum efficiency.In addition, it has a natural gas burner with low NOx emissions.
Steam carries about 540 Kcal/kg of useful energy whereas hot water and thermal fluid carry much less energy. Steam does not require a pump to transfer the energy. Generally, if the heating temperatures required are <100°C, then hot water can be used and if temperatures >180°C are needed then thermal fluid might be a better choice. For process temperatures between 100°C and 180°C steam is considered a viable option.
A thermal fluid system is a closed loop using mineral or synthetic oil as the heat transfer fluid. These systems operate at elevated temperatures while maintaining low system pressures. Fluid is circulated within the heater tubes and flue gases heat the fluid.
1. In terms of boiler body structure, WNS series gas-fired (oil-fired) boilers are fire tube boilers; SZS series gas-fired (oil-fired) boilers are water tube boilers;
2. In terms of boiler working pressure, if the boiler pressure is below 1.6Mpa, the choice is usually the WNS series gas-fired (oil-fired) boiler, if the boiler pressure is above 1.6Mpa, the SZS series gas-fired (oil-fired) boiler may be a better solution. Some high-pressure boilers also adopted SZS series gas-fired (oil-fir...
The air in the economizer and condenser has not drained yet when firing. The safety valves of economizer and condenser need to be turned on to exhaust steam. Return pipe valves also need to be turned on, enabling the steam in the economizer and condenser to return to softened water tank.
The outlet water temperature is so high that economizer and condenser will have vaporization phenomenon. The outlet water temperature of economizer and condenser need to be controlled.
The check valve of the...
