GB191026959A - Improvements in Two-fluid Galvanic Cells. - Google Patents

Abstract

26,959. Hesseln, W. J. Feb. 11, [Convention date]. Arrangement; gas collectors; electrolytes.-In a primary battery having a carbon electrode b acting as a diaphragm, one or more tubes f or the like dipping into the depolarizing liquid form chambers which receive the warm gases and vapours evolved, a pressure being set up which assists diffusion of the depolarizer through the carbon b and varies according to the current. Porous material may be placed against the carbon to increase the effect, as described below, and the arrangement may be modified so that the depolarizer is outside the carbon. In the form shown in Fig. 1, the gases collect between the carbon b and the tube f, which may be of glass, vulcanite, or the like, and force the depolarizer up the central space. Excess of gas after passing through the depolarizer escapes through a perforated stopper e. When action ceases, the outer electrolyte is drawn into the pores of the carbon and prevents diffusion of the depolarizer during rest. In a modification, the tube f extends to the bottom of the carbon b and is perforated or porous at its lower end, the bottom of the carbon being made impervious, if necessary, by paraffin, varnish, or the like. Porous material such as asbestos or glass wool is rammed between the carbon b and the tube f, and when saturated hinders the gases from escaping upwards, causing them to pass through the perforated part of the tube f to the central space, where they collect, the gas exit holes being arranged, in this form, between the carbon b and the tube f. The porous layer keeps saturated while almost any depolarizer remains, rendering the diffusion uniform over the surface of the carbon, and enabling the depolarizer to be renewed without stopping. Porous material may also be placed inside the tube f, all parts within the carbon being removable, but filling is more difficult. Weak or concentrated depolarizers, such as nitric acid which may contain. oxidizing salts, may be used with ordinary electrolytes such as solutions of ammonium chloride, salt, sodium or potassium hydrate, or sulphuric or hydrochloric acid. A little nitric or hydrochloric acid or the like is added to depolarizers giving little gas. A zinc, iron, aluminium, or other metal electrode c may be used. The Specification as open to inspection under Section 91 (3) (a) comprises also tubes f of earthenware or carbon, and a porous layer of glass powder or carbon; this subject-matter does not appear in the Specification as accepted.