Plate heat exchanger

Abstract

Plate heat exchanger consisting of a plate stack ( 2 ) and a housing ( 1 ) surrounding the plate stack, wherein the plates ( 2 a ) are connected with one another in the plate stack ( 2 ) in such a manner that a first and at least one further medium can flow alternately through adjacent plate interstices, and the one medium can be conducted to and away from the plate stack ( 2 ) by way of through-flow channels that run in the stack direction, while the other medium can be conducted to and away from the plate interstices assigned to it by way of an interstice between housing ( 1 ) and plate stack ( 2 ) on the outer circumference. It is essential, in this connection, that the following combination of materials is present: The plates ( 2 a ) of the plate stack ( 2 ) consist, in known manner, of corrosion-resistant material, whereas the housing ( 1 ) consists of a non-corrosion-resistant material that has an enamel coating on its inner side, which is impacted by medium.

1 . A plate heat exchanger comprising a plate stack ( 2 ) of plates ( 2   a ) and a housing ( 1 ) surrounding the plate stack, the plates ( 2   a ) are connected with one another in the plate stack ( 2 ) in such a manner that a first and at least one further medium can flow alternately through adjacent plate interstices, and the first medium is conducted to and away from the plate stack ( 2 ) of through-flow channels that run in a stack direction, while the further medium is conducted to and away from the plate interstices assigned to it by way of an interstice between housing ( 1 ) and plate stack ( 2 ) on an outer circumference, the plates ( 2   a ) of the plate stack ( 2 ) are formed of corrosion-resistant material, and the housing ( 1 ) is formed of a non-corrosion-resistant material that has an enamel coating on an inner side thereof, which is impacted by the medium. 
     
     
         2 . The heat exchanger according to  claim 1 , wherein the housing is formed of enameled black steel. 
     
     
         3 . The heat exchanger according to  claim 1 , wherein the enamel coating has multiple layers. 
     
     
         4 . The heat exchanger according to  claim 1 , wherein the enamel coating includes at least one base coating and at least one cover coating. 
     
     
         5 . The heat exchanger according to  claim 1 , wherein the enamel coating, at least in a cover layer thereof, contains more than 50% SiO 2 . 
     
     
         6 . The heat exchanger according to  claim 1 , wherein the enamel coating, at least in a cover layer thereof, contains more than 3.5% TiO 2 . 
     
     
         7 . The heat exchanger according to  claim 1 , wherein the enamel coating, at least in a cover layer thereof, contains more than 12% Na 2 O. 
     
     
         8 . The heat exchanger according to  claim 1 , wherein the enamel coating, at least in a cover layer thereof, contains at least one of: B 2 O 3 , Ka 2 O, Li 2 O, MoO 3 , MnO, ZrO 2 , or F, in a single digit percentage range, in each instance. 
     
     
         9 . The heat exchanger according to  claim 1 , wherein the enamel coating, at least in a cover layer thereof, contains BaO, CoO, or V 2 O 5 , in a parts per thousand range in each instance. 
     
     
         10 . The heat exchanger according to  claim 1 , wherein the enamel coating has a thickness of about 1 mm to about 3 mm. 
     
     
         11 . The heat exchanger according to  claim 1 , wherein the housing ( 1 ) has welded-on installations ( 1   a ) for guiding the flow, which also are formed of enameled black steel. 
     
     
         12 . The heat exchanger according to  claim 1 , wherein the housing ( 1 ) has welded-on connector pieces ( 5 ,  6 ), which also are formed of enameled black steel. 
     
     
         13 . The heat exchanger according to  claim 1 , wherein the housing ( 1 ) has housing parts ( 1   a ,  1   b ) that are screwable onto one another.