Cylindrical heat exchanger

Abstract

A cylindrical heat exchanger composed of a cylindrical inner housing formed with smooth internal and external surfaces and a cylindrical outer housing shell formed at opposite ends thereof with a pair of cylindrical portions and at an intermediate portion thereof with a plurality of axially equally spaced annular portions partly reduced in diameter, wherein the outer housing shell is coupled with the inner housing such that the cylindrical portions and annular portions of the outer housing shell are engaged with the external surface of the inner housing to form a plurality of axially spaced annular flow passages communicated with each other through communication passages formed at each one side of the annular portions, and wherein a flow passage composed of the annular flow passages and communication passages is communicated at its one end with an inlet formed in one end portion of the outer housing shell and at its other end with an outlet formed in the other end portion of the outer housing shell.

What is claimed is:  
     
         1 . A cylindrical heat exchanger comprising a cylindrical inner housing formed with smooth internal and external surfaces and a cylindrical outer housing shell formed at opposite ends thereof with a pair of cylindrical portions and at an intermediate portion thereof with a plurality of axially equally spaced annular portions partly reduced in diameter, wherein said outer housing shell is coupled with said inner housing such that the cylindrical portions and annular portions of said outer housing shell are tightly engaged with the external surface of said inner housing to form a plurality of axially spaced annular flow passages communicated with each other through communication passages formed at each one side of the annular portions, and wherein a flow passage composed of the annular flow passages and communication passages is communicated at is one end with an inlet formed in one end portion of said outer housing shell and at its other end with an outlet formed in the other end portion of said outer housing shell.  
     
     
         2 . A cylindrical heat exchanges as claimed in    claim 1   , wherein said annular flow passages are communicated with each other alternately in a diametrically opposed position through said communication passages.  
     
     
         3 . A cylindrical heat exchanger as claimed in    claim 1   , wherein the cylindrical portions and annular portions of said outer housing shell are brazed to the external surface of said inner housing in a furnace in a condition fixedly coupled therewith.  
     
     
         4 . A cylindrical heat exchanger as claimed in    claim 1   , wherein the annular portions of said outer housing shell are fixedly coupled with the external surface of said inner housing and wherein the cylindrical portions of said outer housing shell are brazed to the external surface of said inner housing in a furnace.