DE256401C - - Google Patents

Description

IMPERIAL

PATENT OFFICE.

PATENT LETTERING

- Yes 256401 CLASS 21 b. GROUP

for electrical collectors.

Patented in the German Empire on March 10, 1912.

For this registration, the examination according to your union contract of

March 20, 1883

Recognized on December 14, 1900 on the basis of registration in Great Britain on March 21, 1911.

the priority

In collector batteries, separators are often used between the electrodes lying next to one another in order to isolate the plates from one another and, in particular, to avoid short circuits that could occur if the active masses fail. Separators of this type were previously made of cellulose 0. The like, wood or ^: earthenware; kaolin has also been proposed for this purpose.

In any case, the separators must be easily permeable to the electrolyte, so that they do not increase the internal resistance of the cell too much. Where the separators occupying all of the space between the panels, this is especially important. The effective part of the electrolyte is located then inside the porous plates, which therefore have a sufficient capacity for must have him. The separators must not be pierced, otherwise the Holes may short-circuit, and moreover, the active material is lacking these places of a supporting abutment. This disadvantage also applies if the partition plates are corrugated or grooved. Are most suitable ι. therefore separating bodies made of porous artificial stone masses. But they have not yet been properly made.

It was previously only known to make such separating bodies from powdery! To manufacture materials, which are converted into a paste with the help of water or some other liquid and then molded and fired. However, with these methods it is difficult or impossible to remove thin sheets of uniform thickness and absolutely flat surface ^, because during the firing process curvatures occur as a result of the escape of the related fluid. The present invention avoids these drawbacks in that no moisture is used in the manufacture of the panels. It becomes porous plates of more uniform Obtain thickness that has a large capillary capacity and sufficient mechanical strength and are up to 1.5 mm thin.

According to this invention, fine powder is first mechanically compressed and then heated to give it the necessary strength, but not so strong that it becomes one impermeable mass melts together. The lower the heating temperature and the depending the finer the powder, the greater the capillary capacity of such separators

The fine powder can be mixed with a small amount of powdery binding material just enough to be

gains greater cohesion and strength during and after heating.

Two examples are described below with reference to suitable materials. If you have aluminum silicate, as it is in the form of pure kaolin, Cornish stone or bluish Ball clay is used, binding material such as ground feldspar, Flint, bone or lime, use

ίο find. If, however, the separating bodies are to consist of natural silica, fine sand or another pure form of the same and a small amount of aluminum silicate in the form of pure kaolin, Cornish stone or bluish clay (ball clay) can be used as a binding material. The materials must first be cleaned thoroughly. For this purpose, a batch of the base material mixed with the binder is worked through with water in a suitable vessel with the help of paddles or stirrers to form a cream-like mass. The batch is stirred for 4 to 6 hours until it is uniform in consistency; then it is pushed through a sifter or wire screen with about 40 holes per cm ² and then passed into a collecting vessel. This vessel must also be equipped with a stirrer to prevent the insoluble constituents from settling. This mixture is then poured into canvas sacks or the like, through whose pores most of the water is squeezed out. The moist, sticky mass obtained in this way is removed from the sacks and carefully dried in a heated drying room, whereupon the dry material is broken into small pieces in a crushing machine and ground to a fine powder in a dust mill and dried again thoroughly. The fine powder is then placed in a press and pressed under a pressure of approximately 160 kg per cm ² into pieces or sheets of the desired shape.

After removal from the press, the pieces or panels are ready to be fired. she are placed in a fireclay vessel or one made of refractory clay with a powder of ground flint or sand can be packed. In this vessel the plates are heated in a furnace or oven to around 1200 to 1300 °, where the temperature depends on the quality and thickness of the panels to be burned. The firing continues until the panels are completely burned out, which is generally, depending on the efficiency of the furnace, the case in 30 to 40 hours.

With a smooth surface, the separating bodies become more or less flexible in shape Panels made. You can also add a border on one or both sides if necessary or flange that enclose the active material or simply on the edges of the Can limit electrodes. The flanges can be contiguous or spaced be provided to facilitate access of the electrolyte to the active material to enable, also can be provided with flanged separators with those that do not have alternate.

Claims (2)

Patent Claims: 1. Process for the production of separating bodies made of artificial stone mass for electrical collectors, characterized in that dry, powdery material, which suitably contains a binding powder without the use of Moisture is pressed into suitable molds and the dry, pressed mass is then fired will. 2. The method according to claim 1, characterized by the use of the as Material for the manufacture of separators known mixture of silica and aluminum silicate.