JPS5812381Y2 - Catalyst for storage batteries - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a catalyst cell for a storage battery, and aims to simultaneously improve water return efficiency and safety.

Catalyst 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, with conventional methods, if you try to improve the water return efficiency, there will be a safety problem (temperature rise), and to prevent this, you will have to use shields and escape routes to secondarily increase the reactivity, making it complicated. They tended to be larger in size and had a more traditional structure, but they also had some deficiencies in terms of safety.

The purpose of the present invention is to eliminate these drawbacks and to obtain a highly reliable catalyst cell with high water return efficiency, high safety, and simple structure.

The gist of the present invention for achieving this invention is as follows.

That is, in the intracellular space that has exhaust and water return ports on the top and bottom,
By storing the catalyst in a flat porous container whose inner height is less than 0.3 times the diameter, the porous container,
That is, the catalyst container itself has an appropriate ability to limit the reaction.

Next, the present invention will be explained in detail.

In FIG. 1 illustrating an embodiment of the present invention, 1 represents a body;
2 is an inlet and an inlet for introducing gas and returning water; 3 is an exhaust hole;
4 is a hydrogen gas-oxygen gas combination catalyst, for example, palladium is attached to a γ-Al□ carrier; 5 is a cylindrical catalyst container with a narrow gap explosion-proof function made of sintered inorganic particles;
Its shape is a flat one with an inner height that is less than 0.3 times, for example 0.15 times, the diameter.

Reference numeral 6 denotes a m-resistant support base for installing the catalyst container in the intracranial space, and is a molded product made of a material such as ebonite.

In addition, FIG. 2 shows an example of a conventional overcurrent type catalyst cylinder, whose structure is the same as the embodiment of the present invention shown in FIG. 1 with reference numerals 1 to 6. They are very different in that they act to suppress the flow of gas to the catalyst below a certain amount, have a large volume, and have a high saturation temperature.

Further, although the shape of the catalyst container in FIG. 1 is cylindrical, the same effect can be achieved even if the cross section is shaped like a polygonal cylinder.

At this time, the diameter is determined from the area S of the inner cross section and the circumference by D=43/L.

The mechanism of action of this catalyst is as follows.

First, hydrogen gas and hydrogen gas generated from the storage battery flow into the cylindrical body 1 from the lower part 2 of the cylindrical body 1, pass through the wall surface of the catalyst container 5, and come into contact with the catalyst 4, resulting in chemical bonding. It becomes water vapor.

Next, this water vapor passes through the wall surface of the catalyst container 5 and moves to the outside, and is cooled and condensed on the inner wall surface of the body 1.

The liquid water flows back into the battery from the lower part 2 of the cylindrical body 1.

In this way, the gas bonding reaction does not proceed until the gas passes through the wall of the catalyst container.

Table 1 shows the results of tests conducted on this reaction state by changing the shape of the catalyst container.

Further, a diagram illustrating this is shown in FIG.

In this test, the structure of the catalyst vessel shown in Fig. 1 was used, and the catalyst vessel was made by sintering 36 meshes of alumina particles to a thickness of 5 m.
, ventilation resistance 5 rIrrn H2O (blow rate 1.3 t/min), internal volume approximately 10 cc, and 7 g of catalyst stored in each catalyst container. Reaction depending on the shape of the catalyst container. This is a calculation of the influence of current.

The thickness, ventilation resistance, etc. of the catalyst container are within the ranges conventionally used in catalyst containers, and the amount of catalyst is a predetermined amount determined by the capacity of the storage battery.

As is clear from this table, it is shown that the maximum reaction current and temperature can be lowered by flattening the shape of the catalyst container, especially when the height/diameter value is less than 0.3. It has a tendency to be stable, has sufficient water return efficiency as a catalyst, and is highly safe with little temperature rise.

Furthermore, in order to confirm this fact, Table 2 shows the results of tests conducted on catalyst containers whose internal volume was about three times that of the catalyst container used in the previous test.

In this test, the material, physical properties, etc. of the catalyst container were kept under the same conditions as those used in the previous test, but only the internal volume of the catalyst container was increased by about 8 times.

As is clear from this table, even when the internal volume of the catalyst container increases, the height/diameter is less than 0.3.
Compared to those with a value of 0.3 or more, results similar to those in the previous test were obtained.

However, the absolute values of reaction rate and temperature were larger than the previous test results.

The reason for the above results is that unreacted gases and water vapor from the reaction do not enter from the bottom of the catalyst container and exit to the top, but instead enter and exit through the sidewalls of the catalyst container, and the area of the sidewalls is This is thought to have had a large effect on the reaction rate, and it is therefore thought that if the catalyst container was made flat, the area of the side wall would become smaller, thereby reducing the reaction rate.

It is also believed that as the catalyst container was made flat, the overall surface area of the catalyst container, especially the upper and lower surface areas, increased, and as a result, heat dissipation was performed well and the rise in temperature was restricted.

Similar results were also obtained using a catalyst container made by sintering other inorganic particles instead of alumina particles.

Note that in order to reduce the maximum reaction current, it is possible to reduce the amount of catalyst, but this is not preferable because reducing the amount of catalyst tends to shorten the life of the catalyst.

It is also possible to change the physical properties such as the thickness and ventilation resistance of the catalyst container, but this is not preferable since there is a risk of impairing the narrow gap explosion-proof function.

Therefore, the present invention solves the problem of lifetime by storing a predetermined amount of catalyst in consideration of the lifetime, and also constructs the catalyst container with conventionally used materials, thickness, and physical properties to provide a narrow gap explosion-proof function. By making the catalyst container into a flat shape with an inner height of less than 0.3 times the diameter, the catalyst container itself has the ability to limit the maximum reaction current. The catalyst is small, highly safe, and has a large reaction capacity, eliminating the need for secondary barriers.

Therefore, when comparing the performance of catalyst vessels with approximately the same amount of catalyst and catalyst container internal volume, the catalyst vessel according to the present invention has the superior advantages of being smaller and safer, as well as having sufficient reaction capacity. be.

Test results for specific examples of the present invention are shown in Table 3 in comparison with conventional products.

Note that the material, thickness, and physical properties of the catalyst container were the same.

From this table, it is clear that the product of the present invention is small and highly safe.

As described above, according to the present invention, the catalyst container can be made into a flat shape (
H/D is less than 0.3) and has the ability to limit itself to a low reaction current.1. By simply housing it in a cylinder with a simple structure, a small, highly safe catalyst cell with a large reaction capacity can be obtained, and its industrial value is great.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing an example of the catalyst cell for storage batteries of the present invention, and FIG. 2 is a longitudinal cross-sectional view showing an example of a conventional catalyst cell.
FIG. 3 is a characteristic diagram showing the relationship between the height/diameter ratio of the catalyst container and the maximum reaction current. 1... whole body, 4... catalyst, 5...
...Catalyst container, 6... Support stand.

Claims (1)

[Scope of utility model registration request] The height is less than 0.3 times the diameter of the cylinder, 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. A catalyst cell for a storage battery has a structure in which a container containing a hydrogen gas-oxygen gas bonding catalyst is arranged in a porous container having a narrow gap explosion-proof function made of sintered inorganic material particles.