Rapid steam generator

Rapid steam generators are once-through boilers for generating saturated steam . High-speed steam generators are offered with a steam output of up to 3 t (steam) / h at pressures of up to approx. 32 bar.

High-speed steam generators consist of a spiral and mostly multiple nested pipe arrangement (pipe coil) for the generation of water vapor. Piston pumps with a defined volume flow and stage burners are used for the water supply. The feed pump and the burner usually have two power levels. The water volume flow is measured in such a way that almost complete evaporation of the water when flowing through the entire pipe arrangement is guaranteed at the burner output. In this way, water vapor with a certain residual moisture (wet steam) is generated. A downstream steam dryer can reduce the residual water content to 3%.

Rapid steam generators are available in different designs. They consist of a horizontal or standing, smoke-tight, insulated boiler housing. The pipe coil is located inside this housing. Depending on the design, the cylindrical housing is arranged horizontally or vertically. The Loos company manufactured horizontal high-speed steam generators. The upright version has the advantage that it takes up little space. In Fa. Certuss fall are burners used, the fire from above into the housing while at the company. Clayton the burner is inserted from below into the housing.

The main advantages of these steam generators are the quick provision of steam, its compact design and - in contrast to shell boilers - the low acquisition costs. As a result of the small volume of water, rapid steam generators have a low storage capacity. As a result, there are frequent burner switching cycles when the steam consumption changes, which cannot be compensated for by the two-stage power control. This results in a strong thermal alternating load on the coil.

Since it is not possible to monitor the water level on the boiler design, the flue gas temperature at the boiler outlet and the steam temperature are used as criteria for an insufficient water flow and temperature limiters switch off the furnace if the limit values are exceeded.

Literature sources

Fritz Mayr: Kesselbetriebstechnik , 10th edition 2003, ISBN 3-930039-13-3