Four-plate structure box for electrolytic tank

A cassette (1) for an electrolysis cell is disclosed. The cartridge (1) comprises two cooling plates (2) and two electrolyte plates (3 a,3 c) in the form of an anolyte plate (3 a) and a catholyte plate (3 c). The two cooling plates (2) are in contact with each other at one surface, whereby a cooling flow path (5) is formed between the two cooling plates. Each cooling plate (2) contacts the electrolyte plate (3 a,3 c) at the other opposite surface, thereby forming an anolyte flow path (6 a) between one cooling plate (2) and the anolyte plate (3 a) and a catholyte flow path (6 c) between the other cooling plate (2) and the catholyte plate (3 c). The electrolyte plates (3 a,3 c) and the cooling plate (2) are each formed with cooling openings (7 in,7 out) for cooling fluid through the plate (2, 3a,3 c), at least one anolyte fluid inlet (8 in) for anolyte fluid through the plate (2, 3a,3 c), at least one catholyte fluid inlet (9 in) for catholyte fluid through the plate (2, 3a,3 c), at least one anode gas outlet (8 out) for anode gas through the plate (2, 3a,3 c), and at least one cathode gas outlet (9 out) for cathode gas through the plate (2, 3a,3 c).