Heat exchanger and method for heat exchanging

Abstract

A heat exchanger comprises a first and a second fluid circuit extending through the heat exchanger. The heat exchanger further comprises a stack of fluid plates and a membrane arranged between each of the fluid plates where one interspace is formed between each fluid plate and membrane. The first and second fluid circuits are each constituted by a passage extending through the fluid plates and membranes and along the fluid plates and membranes in a least two interspaces. A primary fluid (W) is passed through the first fluid circuit and a secondary fluid (X) is passed through the second fluid circuit such that the primary fluid (W) is passed along one side of a membrane and simultaneously the secondary fluid (X) is passed along the other side of the membrane. Heat is thus exchanged between the primary fluid (W) and the secondary fluid (X) over the membrane.

1 . A plate heat exchanger associated with a first fluid circuit including a passage for a primary fluid and a second fluid circuit including a passage for a secondary fluid, wherein the second fluid circuit is separate from the first fluid circuit and the secondary fluid is arranged to flow through the passage in the second fluid circuit opposite to the flow of the primary fluid through the passage in the first fluid circuit, the plate heat exchanger comprising:
 a stack of fluid plates, each of the fluid plates in the stack having a surface;   membranes arranged in the stack of fluid plates, wherein each of the membranes is between opposing fluid plates in the stack of fluid plates;   a first interspace between a first fluid plate of the opposing fluid plates and a first membrane of the membranes, and a second interspace between a second fluid plate of the opposing fluid plates and the first membrane;   wherein the passage for the first fluid circuit extends through the first fluid plate of the opposing fluid plates, the first interspace and the second fluid plate of the opposing fluid plates, and the passage for the secondary fluid circuit extends through the second fluid plate of the opposing fluid plates, the second interspace and the first fluid plate,   wherein at least one of the passages of the first or second fluid circuits extends along at least a majority of a distance of a length of the plate heat exchanger,   wherein the flow of primary fluid in the first interspace and the flow of the secondary fluid in the second interspace are arranged to flow in opposite directions,   wherein at least one of the first and second fluid plates has at least one side provided with a plurality of supporting ridges, the plurality of supporting ridges extending in rows along the surface of said at least one of the first and second fluid plates, the plurality of supporting ridges and configured to contact the adjacent membrane and which, and   wherein the plurality of supporting ridges together with the adjacent membrane form the first or second interspace for the passage and conduction of fluid.   
     
     
         2 . The plate heat exchanger according to  claim 1 , wherein each of the fluid plates in the stack of fluid plates and the membranes has a substantially similar rectangular perimeter. 
     
     
         3 . The plate heat exchanger according to  claim 1 , wherein the fluid plates and the membranes each have a substantially similar octagonal perimeter. 
     
     
         4 . The plate heat exchanger according to  claim 1 , wherein the fluid plates in the stack of fluid plates are divided into a group of primary fluid plates and a group of secondary fluid plates, and wherein each of the primary fluid plates has a first shape and each of the secondary fluid plates has a second shape different from the first shape. 
     
     
         5 . The plate heat exchanger according to  claim 1 , wherein the stack of fluid plates and membranes are located between an upper and a lower end plate. 
     
     
         6 . The plate heat exchanger according to  claim 5 , wherein the upper and lower end plates form a portion of a housing for the stack of fluid plates. 
     
     
         7 . The plate heat exchanger according to  claim 1 , wherein the fluid plates in the stack of fluid plates include flow channels on opposite sides of each fluid plate. 
     
     
         8 . The plate heat exchanger according to  claim 1 , wherein the fluid plates in the stack of fluid plates are substantially thermally isolating. 
     
     
         9 . A method for exchanging heat between the primary fluid and the secondary fluid in the plate heat exchanger according to  claim 1 , the method including passing the primary fluid along one side of the first membrane and simultaneously passing the secondary fluid along the other side of the first membrane and exchanging heat between the primary fluid and the secondary fluid through the first membrane. 
     
     
         10 . An arrangement for a continuous renal replacement therapy comprising:
 a continuous renal replacement machine including at least one blood pump, and at least one treatment fluid pump;   a disposable blood line associated with the machine which extracorporeally circulates blood being moved by the blood pump;   a fluid distribution circuitry associated with the machine comprising a line for passing effluent fluid;   at least one line for a treatment fluid associated with the machine for passing treatment fluid being moved by the treatment fluid pump, and   a filtration unit arranged between the blood line and the fluid distribution circuitry,   wherein the fluid distribution circuitry comprises a plate heat exchanger according to  claim 1 , the fluid distribution circuitry configured to be fluidly coupled to the effluent fluid line and disposed in thermal relationship with the at least one treatment fluid line so as to provide for transfer of heat from the effluent fluid to the at least one treatment fluid.   
     
     
         11 . A disposable kit comprising:
 a support structure;   a blood line;   a fluid distribution circuitry comprising an effluent line and at least one treatment fluid line where the effluent line and at least one treatment fluid line are each coupled to the support structure and the at least one treatment fluid line includes a U-shaped portion adapted to cooperate with a respective pump; and   wherein the fluid distributing circuitry comprises a plate heat exchanger according to  claim 1 , the fluid distribution circuitry configured to be fluidly coupled to the effluent fluid line and disposed in thermal relationship with the treatment fluid line so as to provide for transfer of heat from the effluent fluid to the treatment fluid.   
     
     
         12 . An arrangement for a continuous renal replacement therapy comprising:
 a continuous renal replacement machine with at least one blood pump, and at least one treatment fluid pump;   a disposable blood line associated with the machine for extracorporeally circulating blood using the blood pump;   a fluid distribution circuitry associated with the machine comprising a line for passing effluent fluid, and   at least one line for a treatment fluid associated with the machine for passing the treatment fluid being moved by the treatment fluid pump, and   a filtration unit arranged between the blood line and the fluid distribution circuitry, wherein the fluid distribution circuitry comprises a plate heat exchanger according to  claim 1 , the fluid distribution circuitry configured to be fluidly coupled to the effluent fluid line and disposed in thermal relationship with the blood line so as to provide for transfer of heat from the effluent fluid to the blood.   
     
     
         13 . A system for continuous renal replacement therapy comprising:
 a continuous renal replacement machine including a blood pump and a treatment fluid pump;   a source of blood;   a source of a treatment fluid, and   plate heat exchanger including:   a first plate and a second plate arranged in a stack, each of the first and second plates including a perimeter;   a membrane between the first and second plates;   a first interspace between the first plate and the membrane;   a blood passage extending through the first plate, a majority of the length of the first interspace and through the membrane,   a second interspace between the second plate and the membrane,   a treatment fluid passage extending through the second plate, a majority of the length of the second interspace and the membrane, wherein the second fluid passage is not in fluid communication with the first interspace and extends in a direction through the second interspace opposite to the direction of the blood passage in the first interspace,   wherein at least one of the first and second plates includes supporting ridges extending from the plate and into the first or second interspace, and wherein the supporting ridges are located inside the perimeter of said at least one of the first and second fluid plates and configured to contact the membrane.   
     
     
         14 . A plate heat exchanger comprising:
 plates arranged in a stack, each of the plates arranged in the stack including a perimeter;   membranes, wherein each membrane is arranged between a respective pair of the plates in the stack;   for each respective pair of the plates, a first interspace between the membrane between the respective pair of plates and a first plate of the respective pair of plates, and a second interspace between the membrane between the respective pair of plates and a second plate of the respective pair of plates;   a first fluid passage extending through the plates, the membrane between the respective pair of plates and a majority of a length of the first interspace;   a second fluid passage extending through the plates, the membrane between the respective pair of plates and a majority of a length of the second interspace, wherein the second fluid passage is not in fluid communication with the first fluid passage, and   wherein the first fluid passage is parallel to and has an opposite flow direction through the first interspace as compared to the second fluid passage at the second interspace, and   wherein at least one of the plates of the respective pair of plates includes (i) a perimeter ridge extending along the perimeter of said at least one of the plates of the respective pair of plates and towards a surface of the other of the at least one of the plates of the respective pair of plates, and (ii) supporting ridges separate from the perimeter ridge and located inside the perimeter of said at least one of the plates of the respective pair of plates, the supporting ridges extending from a surface of the at least one of the plates and into the first or second interspace, the supporting ridges configured to contact the membrane between the respective pair of plates so as to form channels in the interspace for the conduction of fluid.