JPS5910542B2 - Catalyst for storage batteries - Google Patents

Description

[Detailed Description of the Invention] The present invention aims to improve water supply efficiency and safety of catalyst cells for storage batteries,
The aim is to simultaneously improve durability.

Catalytic cells that use a hydrogen gas-oxygen gas combination catalyst are already being used in stationary storage batteries to reduce the frequency of water replenishment and to prevent the emission of acid mist and explosive gas.

However, if the conventional type does not improve the efficiency of water supply, there will be problems in terms of safety (temperature rise). It had a tendency to change. The object of the present invention is to eliminate this drawback and to obtain a catalyst cell which has high water supply efficiency, high safety, simple structure, and high reliability.

The gist of the present invention for achieving this object is as follows. In other words, by making the cylindrical body simple, using a catalyst container with a limiting ability, and limiting the maximum temperature rise due to the reaction ability of the catalyst container, other secondary barriers can be prevented. The object of the present invention is to eliminate the decrease in reactivity caused by such factors, and to obtain a catalyst that has high water dispensing efficiency and is also highly safe and reliable. Next, the present invention will be explained in detail.

In FIG. 1 showing an embodiment of the present invention, 1 is a helical body;
2 is an inlet and an inlet for gas introduction and water supply, 3 is an exhaust hole, and 4 is an exhaust port.
5 is a hydrogen gas-oxygen gas combined catalyst, for example, a γ-alumina carrier with palladium adhered to it; 5 is a cylindrical catalyst container with a narrow gap explosion-proof function made of sintered inorganic particles; There is. Reference numeral 6 denotes a support base for installing the catalyst container in the space inside the cylinder 1, and is a molded product of a heat-resistant material such as ebonite.

Furthermore, Figure 2 shows an example of a conventional type of overcurrent type catalytic converter.
Its structure is the same as the embodiment of the present invention shown in FIG. 1 with respect to symbols 1 to 6, but an inner cover indicated by symbol T that acts to suppress the flow of gas to a certain amount or less is added. For this reason, there are major differences, such as the large volume of the shell metal. The mechanism of action of the catalyst of the present invention is as follows.

Hydrogen gas and oxygen gas generated during charging of the storage battery flow into the cylinder 1 through the inlet 2, enter through the wall of the catalyst container 5, come into contact with the catalyst 4, become water vapor due to chemical bonding, and return to the catalyst. It is discharged from the wall of the container 5, contacts the inner surface of the cylindrical body 1, is cooled, becomes water, and is returned. Further, the remaining gas is exhausted from the exhaust hole 3 as an unreacted gas. Now, if the structure of the catalyst container and the amount of catalyst are selected appropriately, the reaction amount will be saturated at a certain value accordingly, so choose the one with the most efficient and optimal reaction conditions. be able to. By installing this in a space inside a cylinder provided with a simple inlet/outlet and exhaust hole, a catalyst cylinder with the required reaction capacity can be manufactured. An example of experimental results regarding this is shown in Table 1. These results show the relationship between the amount of catalyst and the maximum reaction current when using the same catalyst spiral body, the same catalyst container with an inner diameter of 25 mm and an inner surface height of 25 mm, and changing only the amount of catalyst by appropriately selecting it. This is what is shown. In addition, the maximum reaction current in the table is the current value when the reaction current is saturated, calculated by the following formula, when the charging current flowing through a fully charged storage battery with a catalyst installed is increased in stages. means. As is clear from Table 1, when the above catalyst container is used, the amount of catalyst at about 120°C to 170°C, which is considered to be the optimal catalyst container temperature rise considering catalyst deterioration and wetting, is 3 to 7.
(9).

Further, FIG. 3 shows the relationship between the temperature rise of the catalyst and the return water efficiency, which represents the ability of the water vapor generated by the catalyst to be cooled and condensed into water within the cylinder.

This test result shows that the temperature rise of the catalyst has the most direct effect on the water return efficiency due to its relationship with the cylinder size and catalyst amount, and the practically required value of 90% is approximately 220°C.
It has been found that this is achieved when the catalyst temperature increases as follows.
In addition, water repellents (usually silicone-based, with a heat resistance temperature of approximately 250°C) are used to prevent catalysts and catalyst containers from getting wet.
220℃ to prevent deterioration and extend the service life.
The following catalyst temperature rise values give favorable results. Further, FIG. 4 shows the test results showing the relationship between the amount of catalyst and the maximum temperature rise value of the catalyst using the shape of the catalyst container as a parameter. A in the figure shows the case where the shape of the catalyst container is tall (cylindrical shape with inner diameter 157IgR x inner height 607m), and B shows the case where the catalyst container is medium (cylindrical shape with inner diameter 221!Glt x inner height 30-). ,
C shows the case of a low type (cylindrical shape with an inner diameter of 44 x inner height of 77 g!t), and as is clear from the above inner diameter and inner height, catalyst containers A, B, and C are all They are configured to have approximately the same internal volume of about 111. From this result, it can be seen that even if the maximum temperature increase value of the catalyst is 220° C., there are various combinations of the amount of catalyst and the shape of the catalyst container, for example, 5 g for high container A and 10 y for low container C. Also, from Figure 4, when the internal volume of the catalyst container is the same and the amount of catalyst is constant, the temperature rise of the catalyst can be suppressed to a lower level by reducing the inner height and increasing the inner diameter of the catalyst container. I also know that it is possible. That is, it will be understood that the maximum temperature increase value of the catalyst is influenced by the amount of catalyst and the shape of the catalyst container. The following formula is generalized based on the experimental formula obtained from the experimental results of the relationship between the maximum temperature rise value of the catalyst, the amount of catalyst, and the catalyst container.

Here, Tmax: maximum temperature rise value of the catalyst (c) K: constant mainly determined by the material of the catalyst container W: weight of the catalyst (g) ρ: apparent specific gravity of the catalyst (f!/CC) D: cylinder Inner diameter of the catalyst container (CTrL): The catalyst container is made of 36 mesh alumina with a thickness of about 5mm. at 2.49/m
The material used is sintered to a density of l.
The value of K in this case is 32.3.

The most widely used catalyst is a pellet-like catalyst in which palladium is adhered to a γ-alumina carrier, and W is the weight of the catalyst including the weight of the carrier. ρ is the apparent specific gravity of the catalyst filled in the catalyst container, and takes a value of 0≦1. Therefore, W/ρ indicates the internal volume of the catalyst container. As is clear from this, there are various combinations that can suppress the temperature rise to 220℃, but once the amount of catalyst (5) and apparent specific gravity (ρ) are determined, the volume required to accommodate it can be determined, and as a result, the required volume is determined. shape of the container (inner diameter and inner height if cylindrical)
is uniquely determined.

Next, the experimental results of the present invention are shown in Table 2 in comparison with the conventional product.

To facilitate comparison, catalysts with palladium attached using γ-alumina as a carrier were used in each case so that they had the same apparent specific gravity, and 36 mesh alumina was used in the catalyst container at a thickness of about 5 mesh with the same density. It is sintered so that
The product of this invention has an inner diameter of 401a and an inner height of 87! i! ! T cylindrical shape, conventional type product has inner diameter 20w1t x inner height 3271
A cylindrical one of No. 111 was used. From this table, it is clear that the product of the present invention is small and highly safe.

The results of this experiment are as follows: The inventive product with the shape shown in Fig. 1 and an example of the conventional method with the shape shown in Fig. 2 are configured to obtain the same reaction current. This is a comparison of the external dimensions of catalyst cylinders. As described above, according to the product of the present invention, by selecting the optimal conditions for the amount of catalyst and its apparent specific gravity, it is possible to obtain a small, highly safe catalyst container with a large reaction capacity. The present invention has great industrial value because it can be stored in a space within a cylindrical body having a small structure.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an example of the catalyst cell for storage batteries of the present invention, Fig. 2 is a vertical cross-sectional view showing an example of a conventional overcurrent type catalyst cell, and Fig. 3 is a diagram showing temperature rise of the catalyst and water return. FIG. 4 is a characteristic diagram showing an example of the experimental results of efficiency. FIG. 4 is a characteristic diagram showing an example of the experimental results of the relationship between the amount of catalyst and the maximum temperature rise value of the catalyst using the shape of the catalyst container as a parameter. 1... Cylinder, 4... Catalyst, 5...
...Catalyst container.

Claims (1)

[Scope of Claims] 1. Inorganic particles are burned in a space inside a cylindrical body, which has a path for introducing gas generated within the battery and refluxing condensed water at the bottom, and an exhaust path for unreacted gas at the top. This is a catalyst container in which a hydrogen gas-oxygen gas combination catalyst is housed in a porous container with a narrow gap explosion-proof function, and the maximum temperature rise of the catalyst is 22
A catalyst cell for a storage battery has a structure in which a catalyst container is arranged in which the catalyst amount and container structure are uniformly determined based on the following formula so that the temperature is below 0°C. Tmax=K・([4W/ρD]+0.225πD)^0^. ^5
・(4W/ρπD^3)^0^. ^0^6^5 However, T
max: maximum temperature increase value of the catalyst, K: constant mainly determined by the material of the catalyst container, W: weight of the catalyst, ρ: apparent specific gravity of the catalyst, D: inner diameter of the cylindrical catalyst container.