Waste heat boiler with throttled tube entries - has tube throttling omitted at stagnation points of inlet header

摘要

The boiler has several heating sections each of which is formed by a large number of tubes (7) in parallel with each other with forced circulation through them. Tubes from an inlet heater (8) which it reaches through four equally spaced inlet openings (11). The water entry to each tube is reduced in dia. and covered by a fine mesh screen. This introduces a resistance at the inlet of all tubes which equalises the flow through them. The tubes in the region (9) which forms a stagnation point midway between two inlet openings (11) do not have these restrictions. This reduces the risk of blockage by dirt without interfering with the equalisation of flow maintained by the other tubes.