JPS5640044A - Liquid heating apparatus - Google Patents

Abstract

PURPOSE: To improve the thermal efficiency of the liquid heating apparatus, by employing waste heat recovering apparatus in which combustion gas is made to flow along a passage in the form of an inverted U-shaped for exchanging heat with liquid flowing on the outside of said combustion-gas passage.

CONSTITUTION: At the lower portion of the body 1 of a water heater, there are provided a combustion chamber 4 having an opening 3 for inserting a burner 37, flues 5 and a gas expanding chamber 8 having an outlet 7. In a waste heat recovering unit 2, on the other hand, a peripheral water chamber 26 is formed between an outer case 24 and an inner case 25 with its top and bottom being both closed, and a cylindrical inner water chamber 27 having double walls 30, 31 is formed in the inner case 25 and communicated to water chamber 26 via connecting pipes 28, 29. Further, a gas ascending chamber 32 is defined by inner wall 30 of chamber 27 and communicated to a combustion-gas outlet 7 via a pipe 33. A gas descending passage 34 is defined between inner case 25 and outer wall 31 of chamber 27 for descending gas toward a lower smoke collecting chamber 35 and discharging it from a smoke outlet port 36. The unit 2 is connected to the water heater 1 via an inlet pipe 21 at the lower end of water chamber 26 and an outlet pipe 22 at the upper end of water chamber 26.

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