A water treatment device, comprising: at least a first and a second sheet (305, 310) arranged in a stacked relationship to form a sheet stack, each sheet having a liquid flow field； an inlet path comprising the liquid flow field of the first sheet, the inlet path having a heat exchange region (350a)； an exit path comprising the liquid flow field of the second sheet, the exit path having a heat exchange region (350b)； a metal transfer layer interposed between the first sheet (305) and the second sheet (310) and configured to allow heat to transfer between the liquid flowing in the inlet path and the liquid flowing in the outflow path； a first cut in the first sheet, in which the first cut is separated from and surrounds at least a part of the liquid flow field of the first sheet without crossing the liquid flow field of the first sheet； a second cut in the second sheet, in which the second cut is separated from and surrounds at least a part of the liquid flow field of the second sheet without crossing the liquid flow field of the second sheet, and in which the first and second cuts line up vertically with each other in the stack to form a collective cut that extends through the stack； and a first plate on the top of the stack and a second plate on the bottom of the stack, in which the first and the second plate enclose the top and bottom of the collective cutout creating an insulating chamber to the flow fields of stacking liquids.Un dispositivo para el tratamiento de agua, que comprende: al menos una primera y una segunda lámina (305, 310) dispuestas en una relación apilada para formar un apilamiento de láminas, teniendo cada lámina un campo de flujo de líquidos； una trayectoria de entrada que comprende el campo de flujo de líquidos de la primera lámina, teniendo la trayectoria de entrada una región de intercambio de calor (350a)； una trayectoria de salida que comprende el campo de flujo de líquidos de la segunda lámina, teniendo la trayectoria de salida una región
