THREE-PASS SHELL-TYPE BOILER Russian patent published in 2008 - IPC F22B7/00 

FIELD: heating.

SUBSTANCE: invention is designed for water heating and may be used in heat engineering. Three-pass shell-type boiler is comprised of a housing, arch furnace tube, furnace tubes of second pass and third pass of combustion products. Space between boiler and external shell is used as pass 3 of combustion products and boiler housing is washed up with boiler water from inside. For better heat transfer outer surface of boiler is finned. From one side arch furnace tube and furnace tubes of second pass are ended with transfer floating head, while from the other side they are connected to flange for fixing to boiler housing. They form common structure inserted into boiler housing and it can be pulled out when flange connection is disassembled.

EFFECT: reduction of boiler dimensions and improvement of boiler performance under conditions of water consumption failure or untreated water supply.

2 dwg