Electrolyzers with Monopolar Electrodes

A — Nickel plated, Iron electrodes, B — Gas collecting bells, O — Current supply, D — Current conductors to tho olectrodes, B — Insulation pipe, G, H — Current oonduotors, I — Gas collecting pipe from tho individual bells, K — Gas pipe, L — Asbestos diaphragm. 

In an electrolyzer with double plate electrodes (design Fauser) each electrode is composed of two parallel plates (the anodes are nickel-plated) suspended by bolt V in the dome N or U, situated over the gas collecting bell O (see Fig. 69). From each bell hangs the diaphragm H, made as a narrow long bag which can be closed or opened at the bottom. The current is conducted to each electrode by nickel-plated copper strips P. The hydrogen collected in the dome N flows 

A — Tank, B — Insulators. V — Double plate electrodes. K — Eoinforoemeut of the electrode plates, O — Goa collecting bell, 31 — Diaphragm, M — Collecting bell. N — Hydrogen dome, P — Nlokcl-plated coppor strips (current conductors), S — Holes in the dome, V — Oxygen dome, 1 — Bolts for suspension of the electrodes Ijd the domes. 

Gasale when designing his electrolyzer endeavoured to separate the gases by means of the louvre type electrodes without the application of diaphragm. In 

A — Electrolyzer tank, H — Insulation plates, C — Gastight cover, e, ea — Elertrodo elements (louvres), O — Partitions, H, CII —- outlet of separated gases (Ka, 0 ). 

---

When it is necessary to collect the gases liberated during the electrochemical process because they are either the product required or a troublesome byproduct, the vessel is closed by a suitable cover which usually is used to support the electrodes. In the case of the filter-press electrolyzers with bipolar electrodes the top of the frames usually serves as a cover. Eleotrolyzers with monopolar electrodes are closed by covers made of steel, concrete, cement, stoneware, etc. Seals between covers and vessels or electrodes are made of asbestos cord, bitumen, asphalt, mixture of kaolin and tar, cement, synthetic resins, etc. 

The electrolytical installation consists of a series of stoneware vessels fitted with overflows the vessels are arranged in terraces so that the electrolyte flows through from one into another. The odd vessels are electrolyzers, the even ones are coolers with cooling coils of lead. Each electrolyzer is provided with a number of platinum anodes and graphite cathodes, which act as monopolar electrodes. The anodes are shaped like frames with a 0.02 mm platinum foil fixed on them. The voltage across the electrolyzer is 5.5 to 6 V usually 18 to 20 such units are... 

Electrolyzers for the production of chlorine and sodium hydroxide, including both diaphragm and membrane cells, are classified as either monopolar or bipolar. The designation does not refer to the electrochemical reactions that take place, which of course require two poles or electrodes for all cells, but to the electrolyzer construction or assembly. There are many more chlor-alkali production facilities with monopolar cells than with bipolar cells. 

---