Patent ID: 8281752
Filing Date: 2012-10-09
Classification: F22B,Y02P,Y10T

Abstract:
1. A natural circulation water tube package boiler having a plurality of self-contained steam generating units in tandem, which package boiler comprises (a) a first SGU having (b) a second SGU having (c) a large SGU-connecting duct connecting the rear of the first SGU to the front of the second SGU so that the two SGUs are in tandem; (d) first inter-SGU piping connecting said mud drums for transferring water heated by the mud drum of the second SGU to the mud drum of the first SGU; (e) second inter-SGU piping connecting said steam drums for transferring water from the lower portion of the steam drum of the second SGU to the lower portion of the steam drum of the first SGU; (f) third inter-SGU piping connecting said steam drums for transferring steam from the upper portion of the steam drum of the first SGU to the upper portion of the steam drum of the second SGU; and (g) fourth inter-SGU piping connecting the rear, lower portion of the steam drum of the second SGU and the mud drum of the first SGU, for transferring water from that steam drum downwardly to that mud drum; wherein the membrane walls of the SGUs and the SGU-connecting duct define a flow path for combustion gases which extends from the combustion chamber of the first SGU within the perimeter of the radiant tubes, through the SGU-connecting duct, and through the second SGU around the convection tubes in the forest-like array, and then through the exit opening, without making a U-turn within either SGU.