Vertical multiple passage drainable heated surfaces with headers-equalizers and forced circulation

Abstract

The present invention discloses improved heated surfaces (HS) with vertical multiple passage panels or vertical serpentine coils from straight tubes with connections between them by top and bottom bends. In HS with tube bends there is not any mixing headers—each circuit has a single tube from inlet header to outlet header. This increases mass velocity of flow and improves stability and temperature regulation of tubes. The bottom bends have holes. The bottom bend holes of the adjacent passes are connected with drain header by drain stubs. Each header serves to drain the adjacent tube passes and as equalizing header of pressure/flow. It will help to decrease multivaluedness and maldistribution of flow between parallel tubes of the module. Such design of HS noticeably decreases the corrosion of tubes.

Dependencies are inferred from the claim text.