Patent ID: 9091487
Filing Date: 2015-07-28
Classification: B21D,F28D,F28F,Y10T

Abstract:
1. A double pipe type heat exchanger, comprising: an inner pipe having an axis, and having a first flow path for a first fluid defined therein; and an outer pipe arranged around the inner pipe to define a second flow path for a second fluid between the inner pipe and the outer pipe, wherein the inner pipe includes a spiral groove formed on an outer circumferential surface of the inner pipe to extend along a longitudinal direction of the inner pipe, the outer pipe including a circumferential reduced diameter portion at a location along said axis and extends 360 degrees around said axis of the inner pipe, the reduced diameter portion protruding inwardly so that an inner surface of the outer pipe intermittently contacts the outer circumferential surface of the inner pipe to hold the inner pipe in place and prevent the inner pipe from moving within the outer pipe, and wherein a longitudinally-extending gap exists between the inner pipe and the outer pipe, the gap being at least intermittently blocked by the reduced diameter portion along the longitudinal direction of the inner and outer pipe to allow the second fluid to flow through the spiral groove only, and wherein the second flow path is defined by the spiral groove for allowing the second fluid to flow spirally therethrough and the gap for allowing the second fluid to flow straightforward therethrough, the reduced diameter portion being configured to at least intermittently block the gap such that the second fluid flows spirally through the spiral groove only, and wherein a spiral groove portion among outer circumferential surface of the inner pipe has a space against the outer pipe, and a spiral ridge portion among the outer circumferential surface of the inner pipe is closely contacted with the outer pipe along a circumferential direction.