Patent GB-681895-A (GB)
Title: Improvements relating to pressure electrolyzers
IPC: C25B9/20
Filed: 1951-07-30
Abstract: 681,895. Electrolysers. LONZA ELEKTRIZITATSWERKE UND CHEMISCHE FABRIKEN AKT.-GES. July 30, 1951 [Aug. 12, 1950No. 17990/51. Class 41. In a pressure electrolyser of filter-press type provided with discharge ducts for hydrogen and oxygen separately connected to each cell and leading to gas separators collecting the electrolyte carried over by the gases and from which the electrolyte is returned by a separate duct system to the cells, the gas discharge ducts and the electrolyte return ducts are each in groups of parallel ducts formed by registering perforations in annular cell frames, each of uniform width, assembled to form a cell column, all the perforations being arranged parallel to each other in a common annular zone. A cell frame is shown in Fig. 1, and the edges of three cells are shown to a larger scale in Fig. 2. Each cell frame consists of a flat ring 1 with a raised flange 2 to which is welded a bipolar electrode 13. Diaphragms 12 are clamped between the rings. Three ducts 4a, 4b, 4c are formed for the purpose of leading off hydrogen to a gas separator. Similar ducts in groups of three are provided for leading off oxygen to another gas separator, and for returning electrolyte from the two gas separators to the cells. Radial passages 8, 9, 10, 11 connect the interior of the cells to the ducts 4a, 5a, 6a, 7a respectively. A group of adjacent cells has the ducts connected to radial passages in this manner, but a second group would have radial passages connected to the ducts 4b, 5b, 6b, 7b, while in a third group the radial passages would be connected to ducts 4c, 5c, 6c, 7c. Fig. 5 shows several cells assembled together and connected to a chamber 18, which as shown in Fig. 4, is in communication with gas separators 21, 23. The chamber 18 is divided by a partition 19 into two compartments H 2 , O 2 , each filled with electrolyte up to the level a-b. The compartment H 2  is connected by a pipe 20 to a gas separator 21, the electrolyte carried over by the hydrogen being returned to the compartment by way of a pipe 22. The pipe 20 communicates with all the ducts 4a, 4b, 4c from a group of cells located between the chamber 18 and a plate 27. Pipe 22 communicates with ducts 6a, 6b, 6c from the same group of cells. Similar arrangements exist for cells located on the other side of the chamber 18. The compartment O 2  is connected by a pipe 24 to a gas separator 23 where oxygen and anolyte are received, and the anolyte is returned by a pipe 25. The two gas separators are interconnected by a tube 26. In the electrolyser shown in Fig. 5, ducts 4a, 5a, extend only through the first five cells next to the chamber 18. These are connected by radial passages to the interior of the cells. The ducts 4b, 5b extend through the first ten cells but are connected by radial passages to the sixth to tenth tenth cells only. The ducts 4c, 5c extend through the first fifteen cells but are connected to the eleventh to fifteenth cells. The cells may however be arranged with more than five cells to a sub-group and the electrolyser may comprise a column with several intermediate chambers 18 having separate current circuits.