DE2722690A1 - CATALYTIC ACCUMULATOR STOPPER PLUG - Google Patents

Description

Japan Storage Battery Company Limited D-8000Munich80

and Nippon Telegraph & Telephone Tel 089 / 982085-87

Public Corporation, Telex: 0529802hnkld Kyoto or Tokyo. Japan telegrams: ellipsoid

May 18, 1977

Catalytic accumulator sealing plug

The invention relates to a catalytic cell closure plug for accumulators or collectors.

Catalytic plugs that use a hydrogen / oxygen recombination catalyst have already been applied to stationary accumulators in order to reduce the frequency the refilling of water and prevent the escape of acid vapors and explosive gases. However, none of these previous sealing plugs has proven to be suitable for large-capacity batteries, because attempts, the mass feedback or formation efficiency To increase this Versdilußstopfen, too extraordinary led to large increases in the temperature of the catalyst and consequently to the impairment of the safety of these devices.

The invention is therefore based on the task of eliminating these deficiencies and in particular a simply structured one more catalytic! To create accumulator plugs that have a hone mass return or recovery efficiency and is very safe and reliable.

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This task is defined by what is stated in the appended claims marked features and measures resolved.

Trfindungsgeroaß one or more porous, explosion-proof catalytic converter containers are provided in this sealing plug to accommodate an oxygen / oxygen recombination catalytic converter; of the condensed water vapors are arranged to the collector cell, wherein a vent is also provided in order to discharge the unreacted gases to the outside air. The overall arrangement is so made that the maximum temperature rise of the catalyst exceeds 22O ⁰ C in each container in any case.

The following are preferred embodiments of the invention in comparison to the prior art with reference to the attached Drawing explained. Show it:

Fig. 1 see a vertical section through a kataIyti

Accumulator sealing plug according to a design * form of invention,

Fig. I is a vertical section through a bisner usual Versenlußstopfen,

3 shows a graphical representation of an experimentally determined characteristic curve of the maximum catalyst temperature rise as a function of the class recovery performance,

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4 is a graphical representation of experimentally determined Curves of the maximum catalyst temperature rise as a function of the amount of catalyst and the Shape of the catalyst tank,

5 to 8 vertical sectional views of modified ones Sealing plug according to the invention,

9 shows a plan view of a support base for a number of catalyst containers in the embodiment according to FIG. 8.

10 is a graphical representation of an experimentally determined Curve of the height / diameter ratio of the catalyst container as a function of the reached maximum catalyst temperature rise and the maximum recombination current end

Fig. 11 is a graph showing the relationship between particle size of the catalyst container constituting the catalyst Material on the one hand as well as the maximum achieved catalyst temperature rise and the maximum Recombination stream on the other hand.

The plug shown in Fig. 1 for accumulators has a housing 1, an opening 2 for the entry of the im Accumulator formed gases as well as for the return of the condensed water vapor, a vent 3, a hydrogen / Oxygen recombination catalyst 4, such as on an alumina support adhesive palladium, a porous, explosive

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safe catalyst container 5 made of sintered particles an inorganic substance or a plastic and a support base 6 made of a molded, heat-resistant Material, such as ebonite, for holding the catalyst container in housing 1.

üer Aufoau of the previous catalytic shown in Fig. 2) Closure plug is similar in terms of components 1 to 6 that of FIG. 1, but differs from the construction of FIG. 1 in that an inner Cover 7 is provided for limiting the gas flow to a predetermined size, the stopper a relatively Has a large volume tric size and the saturation temperature is quite high. This previous stopper is discussed in more detail in U.S. Patent No. 4,002,496.

When the device is in operation, gaseous masses flow and oxygen, which are produced during charging, in particular when the accumulator is overcharged, through the opening 2 into the housing 1, these gases passing through the porous walls of the container 5 and thereby contacting the catalyst 4. These gases are converted into water vapor by chemical recombination and passed through the container wall released through again, whereupon they come into contact with the inner surface of the housing 1, condense and through the opening 2 Iber not shown passages between the housing 1 and the base 6 return to the collector cell. The remaining, unreacted gases are over vent 3 to the outside air.

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With an appropriate choice of the structure of the catalyst container and the amount of catalyst, optimal reaction conditions can be ensured under which the amount of the recombined Gas reaches a saturation value. By arranging one or more catalyst containers in a housing, which is provided with a corresponding bottom opening and a gas vent, can be a catalytic sealing plug be formed with the desired reaction performance. These relationships have already been explored, and one example the corresponding test results are shown in Table 1.

TABLE 1 Amount of catalyst (g) Maximum recombi

national current (A)

Maximum maximum temperature rise in temperature of the catalyst-catalyst container ( ⁰ C) ( ⁸ C)

0.3
2.5

5.0 11.5 13.0 16.5

50 65 100 130 125 160 165 210

Annotation:

The catalyst containers used had an internal diameter of 22 mm and an internal height of 25 mm.

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"The apparent from Table 1, is the amount of catalyst, in which a maximum temperature rise of the catalyst container of about 120-170 ⁰ C, inter consideration of the catalyst decomposition and the wetting factors shows, at 3 - g. 7

The relationship between the maximum catalyst temperature rise and the water recovery performance has also been investigated; the corresponding results are shown in FIG. The corresponding tests showed that the dimensions of the stopper body or the amount of catalyst are less important, but that the efficiency of the water recovery or conversion is more directly influenced by the rise in temperature of the catalyst. An efficiency of _90%% of practical for most applications is required, with a maximum catalyst temperature rise of less than about 22O ⁰ C werden.Außerdem achieved is a maximum temperature rise of 220 ⁰ C are also low with respect to the prevention of decomposition which is used to prevent wetting of the catalyst and the catalyst container of a water-repellent material (typically silicone, the good water repellency properties at temperatures up to about 25O ⁰ C shows), Thereby, the operating life of the catalyst can be prolonged.

Fig. 4 shows the relationship between the catalyst amount and the maximum catalyst temperature rise in the case of various Shapes of the catalyst container. Curves A, B and C were created using a large and tall, respectively, a medium or short container.

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Therefore, various combinations of amounts of catalyst and container shapes are possible, with which the maximum temperature rise can be limited to 220 ⁰ C. For example, the amount of catalyst in the tall container (curve A) is g and in the short container (curve C) is 10 g.

The empirical formula for the relationship between the maximum catalyst temperature rise and the amount of catalyst, the shape of the catalyst container etc. was generally determined as follows:

^T max ^{= K} < JO ⁺ ° · ² " ³ ^ ⁰ ' ⁵ (4W / p ^ DV ^i0b5 where mean:

^T max is ^{the maximum} catalyst temperature rise in ⁰ C;

Not a result of the material and the thickness of the catalyst tank and the degree of activity of the catalyst etc. certain constant;

ύ the weight of the catalyst (in g);

ρ is the apparent function of the catalyst and

D is the inside diameter of a cylindrical catalyst container (in cm).

As can be seen from the above equation, zanlreicne combinations are possible in which the catalyst temperature rise is limited to 22O ⁰ C. When the cata-

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The amount of the analyzer is determined first, the shape can be determined (Diameter and height in the case of a cylindrical container) of the required catalyst container determine.

Test results of a comparison of the catalytic sealing plug according to the invention with a previous one Closing plugs of this type are listed in Table 2.

TABEL

Inventions according to the prior art

External dimensions diameter 70 110

(mm) height 100 150

Volume of the plug body (liters) 0.4 1.4

Nominal power for a water

recovery efficiency of

90 * (A) 10 10

Maximum catalyst temperature rise ( ⁰ C) 200 360

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The above table clearly shows that the inventive catalytic stopper has a small grotto and yet 1m compared to the previous device ensures a large safety factor.

In the above embodiments, the maximum catalyst temperature rise in the container durcn appropriate, suitable choice of the amount of catalyst as well as the structure and the shape and Ab "es-, the container measurements on the basis of the above T-equation to 22O ⁰ C limited .

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FIGS. 5 to 8 show further embodiments of the Invention that are similar to the embodiment of FIG. 1 with respect to components 1 to 6, but which have some contain additional modifications.

In the embodiment according to Fig. 5 the maximum temperature rise of the catalyst is thereby limited to 22O ⁰ C, that the inner height of the container 5 to less than 0.3 times of the inner diameter is set. Experimental results with regard to the relationship between the shape or the dimensions (height / diameter) of the catalyst container and both the maximum temperature rise achieved and the maximum recombination current are shown in FIG. 10 illustrates. The catalytic stopper used for this had the general structure according to FIG. 5, the same amount of catalyst by weight being introduced into each container with a capacity of 10 cm. Obviously, the maximum recombination current can be achieved by

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flattening of the shape of the container, * wooei this current tends to be at a height / Stabilize diameter ratio below 0.3.

In the embodiment according to FIG. 6, a shield 7 is arranged around the catalyst container. With this construction, a sufficiently large recombination takes place before the volume of the gas flow reaches a predetermined limit value; once the Vdumen exceeds this limit, the gas flow to the catalyst is shielded, thereby, an increase in catalyst temperature prevents about 22O ⁰ C. The shield 7 can enclose the side wall and the bottom of the catalyst container, or it can be dimensioned so that it shields the entire side wall or only a part of it or only the bottom part of the container.

In the embodiment according to FIG. 7, the increase in the catalyst ^{temperature to 220 °} C. is limited by increasing the particle size of the inorganic substance or of the plastic from which the catalyst container is made. 11 shows a graphical representation of experimental results which indicate the relationship between the particle size of the container material and both the resulting maximum temperature rise and the maximum recombination flow in the event that the container shape and the amount of catalyst remain the same.

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In FIGS. 1, 5, 6 and 7, only one catalyst container is shown in each case. In the case of a rechargeable battery of large capacity a plurality of catalyst containers can be arranged in a vertical stack, can be limited so that the increase in the catalyst temperature to an upper limit of 22O ⁰ C in the manner shown in Fig. 8 way. A suitable support base 6 for a number of such stacked, but spaced apart catalyst containers is shown in FIG. illustrated in top view.

In summary, the invention provides a catalytic accumulator plug with a housing 1, which has a bottom opening 2 and a gas vent 3, in which a porous container 5 made of sintered material is mounted on a support base 6 in the housing and in the Container a filling of a H ~ / Q .. recombination catalyst, such as palladium, is arranged on a γ-aluminum oxide carrier. The gases escaping during charging of the battery enter the housing and penetrate the porous container, contacting the catalyst, where they recombine to form water vapor, which escapes through the container, condenses on the inner surface of the housing and into the collector cell flows back. Oils amount of catalyst, the porosity of the container as well as its dimensions, etc. are in accordance with a fixed, the relationships between the various parameters indicative of equation selected so that the maximum increase in the catalyst temperature can be maintained at a sicneren value of, for example 22O ⁰ C.

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Claims (10)

Henkel, Kern, Feiler Ci Hänzel Patentanwälte 2722600 Möhlstrasse 37 Japan Storage Battery Company Limited D-8OOOMünchen80 and Nippon Telegraph & Telephone Public Corporation. Tel.:089/982085-87 (.orpordtion, Telex: 0529802 hnkld Kyoto or Tokyo, Japan Telegrams: ellipsoid May 18, 1977 PATENT CLAIMS 1. Catalytic accumulator sealing plug with a housing which has an opening in the bottom for the entry of gaseous hydrogen and oxygen escaping from the accumulator and for the exit of condensed water vapor back into the accumulator, with at least one porous, explosion-proof in the housing Catalyst bed ter is arranged, which contains a filling of a hydrogen / oxygen recombination catalyst, and a vent for the exit of unconverted gases is provided in the housing, characterized in that the amount of catalyst (4) and the physical or physical dimensions of the porous catalyst container (5) sina selected so that the maximum increase in the catalyst temperature is restricted to 22O ⁰ C. 2. Sealing plug according to claims 1, characterized in that the catalysts ge and the physical parameters of the cylindrical container (5) are chosen according to the following equation: 7098A8 / 1111 ORIGINAL INSPECTED ^T max ■ ^K < in which words: ^T max is ^{the maximum} increase in catalyst ^{temperature (in 0} C); a constant determined by the material and the thickness of the catalyst container and the degree of activity of the catalyst, etc.; the weight of the catalyst (in g); the apparent service of the catalyst and the inside diameter of the container (in cm), 3. Closure plug according to claim 1, characterized in that the inner height of the cylindrical Container is less than 0.3 times its inner diameter. 4. Sealing plug according to claim i _%, characterized in that the inner hone of the cylindrical container is less than 0.3 times its inner diameter. 5. Closure plug according to claim 1, characterized in that it has a gas-impermeable Aoschirmung which is arranged concentrically around the container at a distance from the container. 709848/1111 6. Sealing plug according to claim 2, characterized in that it has a cylindrical, gas-impermeable ADscnirmung, which is arranged at a distance from the container concentrically around this. 7. Verscnlußstopfen according to claims 1, characterized in that several with a catalyst in the housing filled, spaced apart containers are arranged. 8. Closure plug according to claim 2, characterized in that several with a catalyst in the housing filled, spaced apart containers are arranged. 4 closing plug according to claim 1, characterized in that the particle size of the container material is comparatively large, so that the porosity of Benälters is reduced and the limitation of the rise is favored, the catalyst temperature to 22O ⁰ C. 10. Sealing plug according to spoke 2, characterized in that the particle size of the container material is comparatively large, so that the porosity of the container is reduced and the limitation of the rise in the catalyst temperature to 220 ⁰ C is promoted. 709848/1111