DE2935505A1 - PIPE PLATE FOR LEAD ACCUMULATORS AND METHOD FOR THEIR PRODUCTION - Google Patents

Description

H.-P. Lieck P ~. Tentanv. _: -T .VaximiüaPt-pla'z 10 D-5C .O Xl ^ cren 2?

AB Tudor
P 227 Ol

Tube plate for lead accumulators and methods of making them

The invention relates to lead-acid batteries and in particular relates to the design and manufacture of the positive electrode of lead-acid batteries.

Lead-acid batteries usually include positive and negative electrode plates, which are separated by microporous separators, with sulfuric acid as the electrolyte iient. When discharging, -geiauso on the positive electrode many sulfate ions as needed on the negative electrode. However, water is generated at the positive electrode, and the Porosity decreases more strongly than on the negative electrode, i.e. there is only a smaller surface on the positive electrode available for the admission of sulfuric acid. Difficulties at the negative electrode are minor because of the sulfate ions have a potential that draws them to the negative electrode.

The availability of sulfuric acid on the positive electrode is further diminished in that acid transport is difficult in the microporous separator, and therefore acid migration to the positive electrode is obstructed.

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Attempts have been made to limit the "availability of sulfuric acid." to compensate at the positive electrode by having the separators equipped with ribs, which the positive electrode are opposite. These ribs define channels or pockets for receiving sulfuric acid. Through this the access of the acid to the positive electrode is somewhat improved.

Despite this arrangement, the capacity of the cell by the positive electrode is limited because the acid always has not only hindered access to the positive active H aterial.

To increase the capacity, the positive electrode can be made thinner and more porous, which facilitates the entry of the acid. However, the use of thinner plates requires a greater number of electrodes and separators when the capacity should be retained, which leads to higher costs and also thinner current collectors are necessary, which results in more severe corrosion and a shorter service life. The higher one Porosity also decreases cell life due to the rapid loss of active material from the positive electrode.

These problems are compounded by the fact that the service life of the positive electrode is a function of the volume loss of active material. With high-quality batteries, e.g. for industrial use, positive material, e.g. j cotton wool to support the positive electrode on the surface used during regular discharge to counteract volume loss. Such material, on the other hand, decreases acid transport even more. In some designs, the ribs of the separators are thicker or thinner Replaced layers of porous material, such as glass wool.

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In one proposed in the past the formation of a positive electrode with the aim of having active material a so-called tube plate is used to support and hold it in place and thus improve the service life of the positive electrode used, which comprises a number of parallel tubes or tubes. Each tube includes one in the active material embedded pantograph that is in contact with it. The current collectors are connected by a rail at the top connected to each other. If the tubes of such a tube plate are made of a material such as woven or braided glass, that reflects the pressure occurring during discharge ^ can stand, very small changes in volume can be achieved and thus a good service life of the tube plate.

Pipes have been proposed which are circular in shape in one case and square in another case Shape are. Several circular tubes in contact with one another offer an enlarged surface and thereby enlarged Porosity, compare CH-PS 199 710. The small area between adjacent tubes contains acid which permeates the positive active material. However, one has Such a design of the positive electrode results in an increased ratio of volume to surface area, which is a disadvantage can be. In addition, the small space between the round tubes is insufficient, the positive electrode is sufficient to supply, so that the application reservoir-forming ribs on the separator is necessary.

Even if the round tubes are spaced apart so that additional space is created between them, the capacity of the cell can only be maintained by using additional plates and separators instead of ribs;

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however, this makes the cost of the accumulator significantly higher.

As mentioned earlier, there are also square tubes to increase the surface area of the tubesheet and correspondingly facilitate acid penetration into the positive active material has been proposed. There is a small, more random, spacing of approximately between the square tubes a millimeter through which a minimal amount of acid can get between the pipes. That is why we are also here by ribs created spaces are required so that the positive electrode can be supplied with acid.

In addition, the active material in the electrodes during discharge swells, a pressure occurs in the pipes, which cannot be withstood in a square shape, which leads to The result is that the walls expand and touch each other, possibly after a few tens of discharges. Since a highly efficient accumulator should have a service life of 1,000 to 2,5000 discharges, this training exists practically no free acid between the tubes. Rather, the acid will settle in the pores of the walls and electrode, between the positive and negative plates and on the side and under the plate group.

It has also already been proposed to use tubes with slightly concave side surfaces, between which electrolyte channels are defined, see DE-PS 961 720. The tubes are made of plastic and have horizontal slots for the entry of the electrolyte. However, the capacity of the battery is very limited because there is contact between the Electrolyte and the active material is only possible via the spaced-apart slots.

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As already mentioned, it is expedient to set the ratio of volume to surface area of the positive electrode tube in this way to make it as small as possible. For a square or circular pipe, this ratio is 0.25'd, where d is the diameter of a circular tube or the side length of a square tube. So it is desirable to provide a positive electrode tube in which the ratio of volume to surface (volume-to-surface ratio) is less than 0.25'd, the capacitance of the electrode being maintained or increased at the same time will.

The tubes currently in use only offer very limited external support, which is why they are made from a solid material, e.g. braided or woven continuous fibers, must be made so that they can withstand the pressure generated inside » It is desirable to have such an expensive tube construction ζμ avoid.

When a lead-acid battery is charged after a discharge, the production of oxygen begins when the battery is only 80-90 % charged again, while hydrogen does not develop until it replaces 98-100% of the previous discharge are. It has now been found that the oxygen produced is forced through the separator into the negative plate if the positive and negative electrodes are pressed together with the interposition of only a thin, porous separator. When the negative plate is oxidized in this way, the battery can be fully charged up to 100% without leaking any gas. Such gas-tight high-pressure batteries have recently been brought onto the market. However, since the recombination depends on the pressure between the plates and the thickness of the separator, such batteries suffer from an electrolyte deficiency because of the

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Electrolyte is only available in the pores of the plate or in the thin separator. It would therefore be worth striving for a training in which the pressure in such a battery can be maintained and still abundant Electrolyte is available on the plates.

Accordingly, the invention is based on the object, while largely or even completely avoiding the Above mentioned problems to an electric accumulator with increased capacity with unchanged volume create in which in particular the distance between positive and negative material is effectively reduced and it through outer support of the pipes becomes possible to use very inexpensive material for the pipe walls and so the costs of the pipes significantly reduce. In this context, a positive electrode tube is to be created in which the volume-to-surface ratio is a minimum. The construction to be created should in particular for gas-tight, under pressure standing accumulators should be suitable, in which an adequate pressure can be maintained and at the same time a ample electrolyte supply is available. After all, supposed to a novel process for the production of electrode tubes with a minimal volume-to-surface ratio and a maximum hold between the pipes can be specified.

According to the invention, this object is achieved with the tube plate for lead-acid batteries that emerges from the claims, the one from the The tube plate accumulator which emerges from the claims and the method which emerges from the claims for the production of a Pipe or released from pipes for accumulator pipe plates.

According to the invention, in an electrical lead-acid battery with negative and positive plates, the latter each include several core rods of conductive material spaced apart

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are arranged from each other and each embedded in active material with whom they are in contact «. The active material is located in tubes made of porous fiber, whose Shape gives a volume-to-surface ratio of no more than 0.2 ·· d, where d is the largest dimension of the tube in a Is the direction that goes between the positive and negative plates. The latter is used in one embodiment of the invention achieved by a design in which at least one side of the electrode tube is concave. Preferably the pipe is on concave on both sides, preferably in the manner of an I-beam. The dimension of the positive electrode plate can be in in a direction passing between the positive and negative plates, thereby occupying a space that was previously occupied by the large spacing ribs since the electrolyte previously contained in such fins is located between the electrode tubes in the invention. Corresponding the distance between the positive active material and the negative plates is reduced, which facilitates discharge. The tubes may be held in place by rigid flanges extending between them formed by an integral section are formed by one or both tubes. This can be achieved by forming several connected pipes at the same time where joints between the pipes are rigid to form solid reinforcement flanges. Alternatively you can the pipes are manufactured individually, with stiff, outwardly projecting flanges serving to connect to the other pipes.

Using the invention, the plates can be subjected to pressure assembled so that when a suitable thin separator such as a microporous fiberglass separator is used, the oxygen is pushed through the separator to the negative plate and reacts there and that active material is oxidized. In this way the negative side is kept in a not fully charged state and can do not develop higher.

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In the following, the invention is explained with further advantageous details on the basis of schematically illustrated exemplary embodiments. In the drawings show:

Figure 1 - an isometric, partially broken away view of an electrical accumulator according to the invention,

Figure 2 - a partial plan view of a group of plates (positive active material and separators) on a larger scale than in Figure 1 with a first preferred tube shape or form,

Figure 3 - a top view corresponding to Figure 2 with another preferred tube shape,

Figure 4 - a schmeatized plan view with yet another preferred tube shape,

Figures 5 to 7 - Figure 2 corresponding plan views with others preferred pipe shapes,

Figure 8 - a schematic isometric view of a Device for the production of electrode tubes according to the invention,

Figure 9 - a cross-section through tubes of the continuous type during manufacture,

FIG. 10 - a schematic plan view for illustration the manner in which the width of the continuous tubes decreases as the channels of the Pipes are brought into the desired shape,

FIG. 11 - a cross section through an electrode tube plate according to one embodiment of the invention,

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Figure 12 - a cross section through a single tube during its manufacture according to the invention /

Figures 13 and 14 - cross-sections through the tube according to Figure in two different final shapes or To shape,

Figure 15 - a cross section through a single tube of another preferred embodiment according to the invention,

FIG. 16 shows a cross section through a set of interconnected tubes made up of several interconnected tubes according to Figure 15,

FIG. 17 is a cross-section through another embodiment of a set of interconnected tubes according to FIG Invention,

FIG. 18 shows a view corresponding to FIG. 8 of a device for producing electrode tubes according to the invention.

An electrical accumulator according to the invention comprises as positive Electrode a tube plate with I-shaped tubes 10, the contain positive active material 11, see Figure 1. The electrode plate comprises a tubular jacket 12 from Fibrous material that is resistant to the acid and the reactions in the accumulator. The tubes can have an inner Wall made of braided or interwoven fiberglass and an outer wall made of thin perforated plastic film, which will be explained in detail below with reference to FIGS. 8 to 18. There is an electrical current collector core rod in each tube 13 arranged, which is in contact with the active material. On both sides of the tubes are thin, essentially

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Chen flat separators 14 arranged on both sides have fine teeth or corrugations. One side of the separator 14 rests against the tubes 10, while the other side rests against a negative plate of the cell. Each negative plate comprises a rail 15 with a clamp 15 '. The core bars 13 of the positive plate are connected to a busbar or pole bridge 13! connected, which is provided with a connector is. The plate group is housed in a cell box K for the acid, as is customary.

According to the invention, the tubes 10 have a shape or shape in which the ratio of volume to surface area, in short the V / A ratio is a minimum. Various possible forms to achieve this goal are shown in Figure 2 and Figure 4 (I-shape) / Figure 3 (T-shape), Figure 5 (egg-shape) and Figures 6 to 7 (non-square rectangular shape). Obviously is in either case the largest dimension d of the tube in the direction passing between the positive and negative plates is larger as the smallest dimension e in a direction normal or perpendicular to the direction defined above, compare FIG. 4. Because of this configuration, the V / A ratio can be kept at a value not greater than 0.2 · d is. In comparison, the V / A ratio for a square or circular pipe is 0.25'd.

A minimum V / A ratio is preferably achieved by having the tube with a generally concave surface C on one or both sides, as is the case, for example, with the I-shaped tube according to Figures 2 and 4. The 'through the concave The larger surface area formed by area C also results in better utilization of the positive active material and the acid.

The I-shaped tubes are arranged close to one another, as a result of which a space 16 is formed between them. The total area with such a pipe with! cross-section, however, still has

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a shape that can withstand pressure loads. The concave surfaces delimiting the space 16 form arches; if you use a suitable perforated plastic film E.g. made of polyester (Mylar) or PVC, you can achieve enough strength to match the usual to be able to withstand the pressure that occurs. For other pipes and / or for a further increase in resistance of the pipes against pressure. Supports or brackets

17 in the spaces 16 between the opposing Pipes are provided, see Figure 2. These brackets can be made of polyester or PVC and be formed by the actual connection of the plastic, which results from the melting or melting explained below. -weld the pipes from the plastic film. Impregnated Pipes of the type Cladex or PgS should have a support tube 18 made of perforated plastic film or porous Have material. If all pipes are supported or held in this way, a relatively weak, inexpensive one can be used for them Wall, e.g. a non-woven mat is used. If a glass mat is used for restraint, this can be reinforced by an inexpensive plastic mat.

A preferred method for producing tube plates with holders is described below with reference to FIGS

18 explained.

The box K is sufficiently high that the acid can flow over the top of the electrode. Using the an the top and preferably also at the bottom of the open space 16 has the acid located above the plates free Access to the positive electrodes; this .will reduce the dilution the acid, - which results in a better output. The spaces 16 thus form acid

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Reservoirs and also make it easier for the acid to reach the positive active material from above. The ones in the reserve spaces 16 sulfate ions have a potential that drives them to the negative plates, which is why they at the implementation will happen through parts of the positive active material. The potential therefore favors the entry of sulfate ions in the positive active material. Since the coat is made of fiber, it is practically everyone from top to bottom The tube is permeable to the electrolyte, which is why the entire electrolyte column in the reservoir gap 16 is used and so the contact of the electrolyte with the active material becomes as great as possible.

The reservoir interspaces 16 are sized so that the amount of electrolyte contained in the interspaces 16 is at least 10% of the total amount of electrolyte in the accumulator.

In the embodiment according to FIG. 2, the core rods have 13 elliptical cross-section, creating a certain "peak effect" where the positive active material is thickest. Because the acid diffusion to the core rods is easier in this example and very high corrosion due to too high a pH value is caused, the corrosion is smaller here than with conventional batteries.

The separators 14 are thin and finely ribbed on both sides with a maximum thickness of 0.8 to 1.0 mm. In this way becomes, the distance between the positive and negative electrodes as small as possible, resulting in a low internal resistance results. For example, as shown in Figure 4, the center of mass M of the positive active material is one half of the pipe closer to the negative by the distance R measured from the geometrical center line L of this active material Electrode. As can be seen, the separators 14 represent a

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essential support for the positive electrode plates, unlike the usual ones, with large reservoir-forming ribs provided separators, in which usually only one rib touches a certain pipe. Stand by the invention numerous, e.g. at least 10, teeth of the separator 14 in contact with each tube. Even in cases where the Surfaces of the tubes facing separators are small, as is the case, for example, according to FIGS. 3 and 5, at least touch two teeth such a narrow side. In the invention, therefore, at least 50% of each can be opposite to a separator Pipe side to be held or supported. The separators 14 and the negative electrodes 15 resist that in the pipes pressure created by the discharge, which ensures good life for both the positive and negative electrodes has the consequence.

One advantage of the invention is the very little corrosion on the core rods 13. In the invention, the distance from the pipe wall is to the core rod, which increases the acidity of the core rod, since the acid is easier to get to the core rod can get. The increased acidity on the core rod reduces corrosion. With a usual square or circular Pipe is the distance from the pipe wall to the core rod d - S / 2 or e - S / 2, where S is the thickness of the core rod, d is the minimum dimension of the pipe in one direction and e is the minimum dimension of the pipe in a perpendicular direction. In the invention, this distance is reduced by at least 10%, as illustrated for example in Figure 4, where the dimensions e and S are shown.

Figure 3 shows tubes 10a in T-shape, which means an even larger number of tubes with an even larger surface-to-volume ratio of the active material allows. Similar to FIGS. 1 and 2, an intermediate space 16 remains between the tubes, as a result of which an acid reservoir is formed. In this case, too

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Concave sides of the tubes form arches or vaults that can withstand the pressure. In addition, pressure-absorbing Elements can be inserted between the pipes if this appears necessary. The core rods 13 are as shown in the drawing emerges, except and have a triangular shape corresponding to the shape of the tubes.

In a simplified embodiment according to FIG Tubes essentially egg-shaped. Here the tubes are spaced apart to form acid reservoirs 21. It can be advantageous to arrange the core rod 13 so that the distance from the core rod to a negative electrode is smaller than is the distance between the pipes. As with the other tube shapes, mounting elements, e.g. made of plastic, can be inserted between be arranged in the tubes.

Furthermore, pipes with a non-square, rectangular shape can be used according to the invention; this is shown in FIGS. 6 and 1 . Such a rectangular shape is the simplest. According to FIG. 6, holding elements 23 and 24 are arranged between pipes 10e in order to create an acid-carrying space between the pipes. The mounting elements can be designed as thin polyester elements. In order to prevent the acid from directly passing over from the area 25 to the negative plates, the sides of this area towards the separator can be covered with a plastic film.

Figure 7 shows an embodiment with non-square rectangular Tubes, in the case of which brackets 26 are made of a porous, volume-stable or volume-retaining material, e.g. porous or porous PVC, porous polystyrene, impregnated cellulose, porous polyester, porous olefin, glass wool or wood are. These can be an end-piece component of the separators 14.

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In all of the described embodiments of the invention the surface of the tubes 10, 10 a, etc. can be increased in that the Itfandung at least on one side is corrugated or ribbed. The tubes 10, 10a, etc. can also be embodied in a bonded formation without a tube wall. It is essential for all forms of training of the invention that that the active material is shaped or arranged to give areas the volume of which is 20% of the acid outside which make up electrodes and which act like an acid reservoir or chimney that creates an acid depletion on the positive prevents active material, as occurs in almost all known lead-acid batteries.

A preferred method will now be described with reference to FIGS explained for the production of electrode tubes according to the invention.

According to FIG. 8, two-fiber masses 30A and 30B are made from two guide rollers 34A and 34B are fed to parallel supply rollers 32A and 32B. The webs can be made of matted or woven Fibers made of glass or plastic, e.g. made of polyester, propathene or other acid-resistant plastic. the Webs are heated in a heating unit 36 during delivery. There are pressure rollers in the working direction behind the heating unit 38A and 38B arranged, namely a uniform mutual distance in the direction of the web width, i.e. transversely to the longitudinal or working direction. Before the webs these pressure rollers pass, plastic mesh webs 40A and 4OB are fed from supply rolls 42A and 42B and to the outside of the Lanes 30A and 30B applied.

The net webs 40A and 40B are intended to form an outer jacket for the pipes, which gives the pipe walls strength and rigidity confers. This is necessary when the webs 30A and 30B do not themselves have sufficient strength or density, which is e.g. is the case with a matted fiberglass mat. Instead of

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A plastic sheet can also be used for a plastic net which is tightly perforated in the entire area.

The pressure rollers 38A and 38B have a smooth mutual Distance half the circumference of the finished pipe is equivalent to. The width of each pressure roller corresponds to the width of a mounting or support flange between adjacent Pipes should arise in a manner to be explained. When the webs 30A and 30B are woven or braided mats of thermoplastic Material, for example made of propathene, causes a high level of heating in the thermal unit 36, while an additional one Heating takes place in connection with or at the pressure rollers 3 8A and 38B, e.g. by means of hot air. Here is how heated until the softening or melting point of the thermoplastic material is reached. Then there is a meltdown or welding the melting tracks 30A and 30B in the areas in which they are pressed together by means of the pressure rollers will.

When used to form webs 30A and 30B, glass or polyester is, strips of the tapes 44 made of polyethylene or propylene are peeled from supply rolls 46 and between the webs 30A and 30B introduced. Under the influence of pressure and heat on the pressure rollers 38A and 38B, the ribbons 44 melt into them Tracks 30A and 30B in and weld them together. During this stage of operation, the lanes 30A and 30 transfer 30B, which in the heating unit 36 is at a temperature above the softening temperature The temperature of the plastic tapes 44 has been heated to the temperature lying below, heat to the tapes. The bands 44 can consist of a mesh or perforated foil. Usually it is best to use such tapes, because then the welding point has the necessary rigidity. However, if the network of tracks 40A and 40B is thick enough, the tapes may be superfluous. The network structure is also

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melted or fused in the same manner as explained above as the bands 44, the thick plastic penetrates both webs 30A and 30B in the molten state and welds them together.

Radiation, blowing with hot gas, ultrasound or high frequency can alternatively be used to heat the webs 30A and 30B and the tapes 44 that may be used the tapes contain 44 polyolefins. Their straight molecular chains are not heated, but only the glass or the plastic of the tracks 30A and 30B “In this way one can achieve that the nets or ribbons melt into the tracks 30A and 30B without changing their volume by being mediated by the heat a fusion of the nets and bands with the tracks 30A and 30B brings about =.

Since plastic nets often contain tension, it is important to that the tracks 30A and 30B and not the tracks 40A and 40B are heated, since the latter comprise the mesh. then the plastic melts into the webs. Therefore, a net structure extruded in two planes is a Netlon net structure particularly suitable, since only one of the levels has to be melted into the strips here »This applies to the surface of the pipe, where the pressing is carried out by means of cylinders or rollers, but not for the welded connection, at which the compression is carried out by means of the pressure rollers 38A in order to insert the net structure in its entirety into the Press in the welded joint. Therefore, the pressure on the actual weld joint must be greater.

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FIG. 9 shows the result achieved with the procedure explained. Between the welded joints or Layer locations 48 are flat tubes which define shallow channels 50 on the outside of an outer mesh jacket 52 are surrounded.

A similar product can be used in conjunction with the illustrated Procedure obtained if instead of two separate Webs 30A and 30B withdrawn from the supply rolls 32A and 32B, a single so-called cassette-belt woven Web is fed into the thermal unit 36. Such a cassette web comprises a woven structure, which is woven web sections which form longitudinally running flat channels which are formed by longitudinally running woven "connections", so-called changeover or displacement points, which are separated from each other, which connect the welded connections 48 of the are comparable with the product explained in FIG. The shallow channels are through upper and lower sections of the Cassette track formed, the width of which is half the circumferential length corresponds to a pipe. The width of the web connections corresponds to the desired dimension of the support flanges between adjacent pipes, which will be explained later.

After the webs 3OA and 30B have been welded together, the flat channels 50 guided in the longitudinal direction over stationary flat mandrels 53, see Figure 9, which between the Welded connections are arranged and enter the channels.

If desired, the mandrels can be heated electrically, to maintain the temperature of lanes 30A and 30B.

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The flat mandrels can be connected to mandrels or merge into those which correspond to the finished tubes Have shape. In this way the channels 50 are enlarged, with the overall width of the material decreasing, see Figure 10.

If the webs 3OA and 3OB and / or 40A and 40B consist of a thermoplastic, e.g. polypropate, possibly together with other fibers that do not need to be thermoplastic, the shaping process can proceed very quickly so that the mandrels only need to hold their final shape over a length of a few centimeters, whereby the heating of the webs takes place before the material runs along the mandrels, while the cooling of the webs takes place takes place while running along. The rigid welds 48 can be used during this forming process Can be used to press the pipe walls in such a way that the shape shown in Figure Ή, for example, is achieved? however can external shaping tools can also be used for the same purpose. If you only want to manufacture the tubes individually, you can this is done with the help of pressure rollers and the like. If the pipes are impregnated with phenol or with a If a similar material is to be stabilized in which hardening is necessary, the shaping process must of course be extended to a longer period of time.

The mandrels and other shaping tools used can, always related to the material movement, are mechanically anchored downstream so that the entry of the mandrels into the pipes according to Figure 9 is not hindered during the advance of the material. Alternatively, magnetic anchoring can be used, which enables the material running over the mandrels and the tools to be heated by eddy currents.

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FIG. 11 shows an electrode plate, the outer jacket of which 60 comprises the aforementioned material, the tubes of which are brought into an I-shape by being passed over I-shaped mandrels and then filled in with lead and active material 67. The connecting spaces 48 form rigid support flanges between the pipes and serve as spacers between this.

Individual tubes can be made in the same manner as previously discussed, with a sheet 30A (or 30B) folded together as shown in FIG. A seam is then defined by the ends of the web 65 made by welding, for example. Starting from the flat state, the sides 66 and 68 of the channel then become expanded to the desired shape, e.g. to the shape according to Figure 13, which shows a circular tube, or to the I-shaped Tube 70 according to FIG. 14.

So far, the pipes were made by joining or lap welding manufactured. Since the heat can only be supplied from the outside in view of the continuous production the welding length is relatively large, possibly up to 1.5 m. In the case of the invention, butt welding can be carried out using from heat from both sides by means of the pressure rollers 38, whereby the plastic melts into the webs 30A, 30B and so a stiff weld is achieved.

Figure 15 shows a rectangular tube 79 made in accordance with the invention, while Figure 16 shows a plurality of such tubes joined together to form a tube sheet , the welded joints forming spacers 79A between the tubes.

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Other geometric tube shapes can also be produced with the method according to the invention »If you For example, if the production of a T-shaped pipe according to Figure 3 wishes, flat channels with connections or hemming of the desired width made in the manner previously explained and then with the help of inner mandrels and outer Shaping tools are shaped so that a tube plate 81 according to FIG. 17 is obtained Making pipes and then assembling them to form the pipe plate "

In another embodiment of the invention Process are pipes made of prefabricated braided or woven stockings or tubes made of glass or respectively Plastic fibers produced according to FIG. 18 = the tubes 80 / coaxial rolls 82 are fed and then drawn onto flat mandrels, with even tubes between adjacent hoses Gaps remain. Meshes 40A and 40B are pressed onto the outer sides of the flat tubes, with those Parts of the nets that bridge the spaces between the hoses are welded together in the manner explained above to form stiff flanges between the hoses. The shallow channels between the flanges can can then be expanded in the manner previously explained to form tubes of the desired shape Straps 44 of plastic are placed over the spaces between the hoses so that they fit into the welded joints as shown to be melted down »

It should be noted that the welded joints do not necessarily have to go through lengthways. It can too pressure members extending transversely to the feed direction of the material can be provided, which the webs intermittently touch to form welded joints.

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In the case of gas-tight, pressurized accumulators, as already mentioned, those according to the invention do it shaped tubes, especially the I-shaped tubes, possible to maintain pressure between the electrodes and still use thin, fibrous, microporous separators. In this case, electrolyte is abundant the ducts between the tubes are fed, if necessary, via the open upper ends of such ducts.

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Claims (16)

Dipi.-lng. H.-P. LieCK patent attorney Maximiliansplatz 10 D-8000 Munich 2 AB Tudor P 227 01 claims 1. Tube plate for electrical accumulators, characterized by tubes (10) made of porous fiber fabric with a shape such that the ratio of volume to surface area of the active material (11) is not is greater than 0.2 times the thickness of the tubes in the direction between the negative electrodes (15) runs on opposite sides of the tube plate. 2. Tube plate according to claim 1, characterized in that that at least one side of each tube (10) has a concave surface. 3. Tube plate according to claim 2, characterized in that the concave tube side is made of a material exists that is strong enough to withstand the expected pressure of the active material (11) » 4. Tube plate according to claim 1, 2 or 3, characterized in that the tubes (10) consist of one fiber reinforced with thermoplastic. 3 0 01 1/0889 5. tube plate according to claim 4, characterized that non-woven fiber fabric is provided and the reinforcing thermoplastic exists as a network. 6. tube plate according to claim 4, characterized that non-woven fiber material is provided and the reinforcing thermoplastic as perforated film is present. 7. tube plate according to one of claims 1 to 6, characterized in that laterally extending Connections (17; 18; 23; 24; 26) adjacent pipes (10) connect with each other and are designed as rigid support elements for the tubes. 8. tube plate according to claim 7, characterized in that the rigid support elements (17) of an integral part of the pipe wall are formed. 9. Tube plate according to one of claims 2 to 8, characterized characterized in that the concave surface is between adjacent tubes (10) and that two Separators (14) are arranged between opposite sides of the tubes and the negative electrode (15) and support each of the two sides with at least two projections. 10. Tube plate according to claim 9, characterized in that the two separators (14) each support one of the two opposite sides on at least 50% of the side surfaces - 11. Tube plate according to claim 10, characterized in that each separator (14) is substantially is flat and made of fiber. 030011/0889 _{/ 3} 2335505 " 12. Electric accumulator with positive and negative plates and a separator between them, in which plates and separators are assembled under pressure to force oxygen through the separator for a reaction on the negative plate during charging, characterized in that each positive plate tubes (10) made of porous pulp having a shape such that the ratio of volume to surface area of the active material (11) is not greater than 0.2 times the thickness of the tubes in a direction extending between the negative electrodes ( 15) runs opposite sides of the tube plate , with at least one side of each tube having a concave surface. 13. Process for the production of a pipe from fiber material for covering a lead plate of an electrical accumulator, characterized in that, that one provides web sections of fiber material, which are arranged one above the other and on both sides to form of a channel are connected to one another, the tracks on at least one side by a welded connection are connected, which extends laterally with respect to the axis of the channel and is rigid, and in that the web sections forming the channel are separated from one another to form a tubular shape which is the one desired Shape of the lead plate resembles such that the welded joint has a stiff flange for connection of the channel with another channel and forms a stiff support flange between the two « 14. The method according to claim 13, characterized in that that the channel is converted into 1-form 030011/08 8 5 15. The method according to claim 13 or 14, characterized that a core rod of complementary shape to the tube is inserted into each tube. 16. Process for the production of tubes made of fibrous material for covering lead plates of an electrical accumulator, characterized in that there are two webs of fibrous material, which are arranged one above the other are, transported, that heat and pressure are used to interconnect the webs at spaced apart strip zones for formation from channels which are separated from one another by the stripe zones, the stripe zones between adjacent Channels are continuous and stiff, and that the web sections forming the channels are separated from each other lifts off and converted into a tubular I-shape, wherein the stiff strip zones extending therebetween form stiff reinforcing flanges. 030011/0889