Horizontal Steel Boiler Steam Drum Boiler Parts For CFB Coal Fired Boiler

Long Life Steel Boiler Steam Drum Boiler Parts For CFB Coal - Fired Boiler

Product Description

The concept of drum refers to the pressure drop or rise caused by the water circulation. It can also be understood that the drum is the pressure change formed by the fusion of gas and water. The air and water molecules in the limit pressure will increase the pressure rise of the gas, resulting in the pressure gathering molecules producedafter the high pressure reaches a certain value. In industry,drum tank is an industrial equipment which can withstand the air pressure and water level pressure produced by the drum.

Steam drum is the most important pressure component in natural circulation boilers. It is mainly used in medium pressure and high pressure subcritical boilers in power generation.

Drum is a cylindrical pressure vessel used in water-pipe boiler for steam and water separation and steam purification, forming a water circulation loop and string pot water. Its main function is to receive the water from economizer, separate steam from water and supply water to circulation loop, and transport saturated steam to superheater. There is a certain amount of water in the drum, which has a certain of heat and material savings. When the working conditions change, the speed of vapor pressure change can be slowed down. When the water supply and load are not coordinated for a short time, it plays a buffer role. The drum is equipped with internal devices for steam-water separation, steam cleaning, pot medication and continuous sewage discharge to ensure steam quality, as shown in the figure.

Drum is the most bulky and expensive thick-wall pressure-bearing component in boiler. The drum not only withstands high internal pressure, but als produces thermal stress due to the fluctuation of wall temperature caused by the change of operating conditions. Therefore, the working conditions are bad, the effective operation condition supervision is needed.

Structure and material

The working conditions of drum are complex and the consequences of accidents are serious. It is necessary to strictly control the chemical composition, mechanical properties and welding and processing quality of material used in drums, and to pass a series of strict tests. The cylinder is composed of a cylinder body and a head.

1. Cylinder:refers to the cylinder part of the drum. Its inner diameter and length are related to the circulation mode, boiler capacity, steam parameters and the structure of inner equipment. Steam drum is usually rolled on multi-roll reel machine. The drum wall of subcritical pressure boiler is too thick to be pressed on giant press.

2. Head: Subcritical pressure boilers are usually hemispherical, high pressure and ultra high pressure boilers are ellipsoidal, medium pressure boilers are relatively flat ellipsoidal, with manholes on the head for installation and maintenance of internal devices. The head is pressed on a hydraulic press or an oil press.

Working procedures

1. The mixture of steam and water coming from the water wall enters the drum through the upper inlet pipe of the drum. Along the narrow annular passage formed by the inner wall of the drum and the arc liner, the steam-water mixture can be uniformly transferred to the inner wall of the drum at an appropriate flow rate, thus overcoming the difficulty of excessive temperature difference between the upper and lower walls of the drum during start-up and shutdown of the boiler and enabling faster start-up.

2. The steam-water mixture entering the drum enters the steam-water cyclone separator, and uses the inertia of changing the flow direction to separate the steam-water mixture, which is the first separation of the steam-water mixture.

3. The separated steam still contains a lot of water. It enters the corrugated plate separator from the top of the separator. The steam with some water droplets flows through the cracks between the corrugated plates, and the water film is formed on the metal wall to flow downward.

4. The steam after secondary separation is finally cleaned by steam, and gravity separation is carried out by using the density difference of water, which is the third separation.

5. After three separations, the steam meets the steam quality standard, and leads to the platen superheater from the saturated steam pipe at the top of the drum.