JPH088095B2 - Storage battery with electrolyte stirring device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a storage battery provided with an electrolytic solution stirring device.

Conventional technology and its problems Since the electrolyte is a substance that directly participates in the reaction of the storage battery, the capacity of the storage battery is greatly affected by how effectively the electrolyte is used in the storage battery, like the active material of the electrode plate. This is well known.

However, in the case of a lead storage battery, since the electrolyte solution above the storage battery is often used during charging / discharging, the specific gravity of the electrolyte solution above the storage battery becomes low, and the electrolyte solution with a high specific gravity remains at the bottom of the storage battery.

In order to eliminate such a difference in concentration of the electrolytic solution, overcharge is applied to generate a gas, and the stirring action of this gas makes the specific gravity of the upper and lower electrolyte solutions uniform. In this case, if the shape of the storage battery is vertically low, it is relatively easy to make the specific gravity of the electrolyte uniform by overcharging, but in the case of tall batteries such as storage batteries for electric vehicles, it is not uniform with a little overcharge. is there. As a result, the capacity of the upper part of the electrode plate becomes low specific gravity and the capacity decreases, and at the lower part, the electrolytic solution having a high specific gravity and rich in oxidation always remains, so that the lower end part of the electrode plate is corroded and the life is shortened. The result is. For this reason, the storage battery is overcharged each time it is charged, power is wasted, and the life of the storage battery is shortened.

Also, in the case of stationary storage batteries, various loads are connected to the storage batteries, and there are loads that dislike large voltage fluctuations due to charging, so a constant voltage charging system that cuts the charging voltage at a constant value may be adopted. In the storage battery for this kind of application, the above-mentioned phenomenon becomes more remarkable. In order to solve these problems, uniform charging is carried out for a long time of 12 to 24 hours, but since the uniform charging voltage is low, it is the current situation that the above problems cannot be solved sufficiently. .

In the large capacity stationary battery for load leveling, air is forcibly fed in from the outside and agitation is performed regularly. As a result, it has been confirmed that the battery life is about twice as long as that with or without the stirrer. In addition, the amount of charge for each charge can be saved by 10%, and as a result, the consumption of water in the electrolyte due to overcharging will be extremely reduced, resulting in a five-fold increase in the rehydration period and a significant reduction in maintenance costs. It has a great effect.

However, since the stirring device currently applied is a forced liquid stirring device by an external device, it requires a compressor pipe and the like, and the cost is high, so it is limited to a battery for a special purpose.

Means for Solving the Problems The present invention provides an electrolytic solution stirring device that solves the above-mentioned drawbacks by self-energy applying gas generated in the battery, rather than a forced stirring device by a storage battery external device. , Having a small hole in an intermediate portion and arranged vertically in the electrolytic solution, and a lower end opening below the small hole position of the liquid circulating cylinder and arranged on the electrode plate group. A gas collecting chamber, the small hole and the gas collecting chamber are connected to each other by an inverted U-shaped siphon strap, a gas reservoir is provided at an upper end opening of the liquid circulation cylinder, and the gas collecting chamber is provided. It is characterized in that the chamber is provided with ribs.

Embodiment Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of a storage battery equipped with the electrolytic solution stirring device of the present invention, and FIG. 2 is a partially cutaway perspective view of the electrolytic solution stirring device.

In the figure, A is a battery case containing the electrode plate group, B is an electrode plate group, C is an electrolytic solution, and D is an electrolytic solution stirring device.

The electrolytic solution stirring device D has a lower end opening at the bottom of the battery case, an upper opening near the minimum liquid level of the electrolytic solution, and a liquid circulation cylinder 1 having a small hole 4 in the middle, and a lower end opening below the small hole 4. And a gas collection chamber 2 for collecting the gas generated from the electrode plate group B.
And the gas collection chamber 2 and the small hole 4 of the liquid circulation cylinder are opposite U
It is connected by a character-shaped siphon strap 3. A gas reservoir 5 is formed at the upper end opening of the liquid circulating cylinder 1 by means such as covering the lower surface with a cap having an open bottom, or folding the upper end of the liquid circulating cylinder into an inverted J shape. .

In the embodiment shown in the drawings, the liquid circulation cylinder 1 has a shape that is displaced and bent at the portion of the small hole 4, but this is used when the stirring device is integrally molded with synthetic resin. This is for facilitating the operation, and is in no way different from the linear one in operation.

Further, in the gas collection chamber 2, a vertical rib 6 and a horizontal rib 7 are provided.
Is provided. The vertical ribs 6 are provided in parallel or in a radial direction toward the siphon strap 3 from the end of the gas collection chamber 2 to just before the entrance to the siphon strap 3. The height of the vertical rib is almost the same as that of the gas collection chamber 2. Further, the horizontal rib 7 is formed with a rib having a height of about 1 mm in a direction orthogonal to the vertical rib 6 at a position 5 mm into the vertical rib 6 from a position where the vertical rib 6 is cut before the entrance of the siphon strap 3.

Depending on the size of the gas collection chamber as in the embodiment, several horizontal ribs 7 having a height lower than that of the vertical ribs 6 may be further provided in the vertical ribs 6.

The stirrer of the present invention has the structure as described above, and when gas is generated from the electrode plate group B when the storage battery is charged, the gas is trapped and accumulated in the gas collection chamber 2. Inverted U-shaped siphon strap 3 according to the accumulation of gas
The electrolytic solution that has entered the inside is returned through the small holes 4 into the liquid circulation cylinder 1. The amount of accumulated gas in the gas collection chamber 2 increases,
When the gas reaches the position of the small hole 4, this gas is extruded from the small hole 4 into the liquid circulation cylinder 1 as bubbles, and the magnitude of gas pressure in the gas bubble and the gas collection chamber is higher than that of the small hole 4 of the liquid circulation cylinder 1. When it becomes a size that overcomes the electrolyte pressure in (1a),
The gas bubbles are the electrolyte above the small holes, that is, the liquid circulation cylinder.
The electrolytic solution in the portion 1a rises while being pushed up, and is discharged from the upper end opening of the liquid circulation cylinder 1 together with the electrolytic solution. At the same time, the liquid pressure in the liquid circulation cylinder 1 decreases, so that the electrolytic solution at the bottom of the battery enters and rises from the opening at the lower end of the liquid circulation cylinder 1, and the electrolytic solution having a large specific gravity in the liquid circulation cylinder 1 becomes a small hole 4. It is pushed up further and is stabilized at a position that balances with the liquid pressure of the electrolyte around the liquid circulation cylinder. From this state, the gas generated from the electrode plate group is accumulated again in the gas collection chamber 2, and the above operation is repeated.

In the device of the present invention, the gas reservoir 5 is provided at the upper end opening of the liquid circulation cylinder 1 to block the electrolytic solution in the liquid circulation cylinder 1 and the surrounding electrolytic solution by the gas phase. Even if the upper end opening is below the surface of the electrolytic solution, the electrolytic solution around the upper end opening does not flow back into the liquid circulation cylinder, and the electrolytic solution always moves from the lower end of the liquid circulation cylinder toward the upper end.

Further, in the apparatus of the present invention, by providing the vertical ribs 6 and the horizontal ribs 7 in the gas collection chamber 2, the collected gas is divided into a plurality of pieces and moves to the siphon strap 3 in this state.

Hereinafter, the operation of the device of the present invention will be described more specifically with reference to FIG. FIG. 3 is an operation explanatory view of the device of the present invention.

 In the description, the symbols in the figure are noted.

ρ ₀ … Top specific gravity of electrolyte ρ… Specific gravity of electrolyte at bottom of battery H ₁ … Head between liquid surface and small hole H ₂ … Head between liquid surface and bottom of gas reservoir H ₃ … Small hole 4 and lower end of liquid circulation cylinder 1 water head of the water head H ₄ ... small hole 4 and the gas collecting chamber 2 lower the hydrohead hx ... small hole 4 and an inverted U-shaped gas collecting chamber side gas-phase surface of the siphon strap 3 of the hy ... liquid circulation tube 1 Water head between the inner upper liquid surface and the small hole 4 Δp1… Surface tension generated at the small hole 4 portion Δp2… Surface tension generated at the lower end of the gas reservoir 5 Fig. 3A shows that the generated gas is an inverted U-shaped siphon The state in which the electrolytic solution having a heavy specific gravity ρ at the bottom of the battery case is gradually stored in the strap 3 and enters the liquid circulation cylinder 1 is shown. The liquid in the small hole side pipe is pushed into the liquid circulation cylinder through the small hole 4 due to the increase in pressure in the siphon strap, and the gas in the pipe is about to enter the liquid circulation cylinder through the small hole 4. The pressure balance at this time is (H ₁ + hx) ρ ₀ = H ₂ ρ ₀ + hyρ + Δp1 + Δp2 (1). In this state, if hx is slightly increased, the above relational expression is broken, and as shown in FIG.
The electrolytic solution in 1a jets out from the upper end. At this time, since the pressure in the liquid circulation cylinder is reduced by the amount of the ejected electrolytic solution, the pressure in the gas collection chamber side pipe of the siphon strap is also decreased, and thus the electrolytic solution rises in the inverted U-shaped siphon strap. . At this time, the position where the liquid level rises is the upper end in the liquid circulation cylinder in the static pressure balance type, but since the liquid level rises strongly, it rises from the liquid circulation cylinder upper end due to inertia,
It is desirable that the upper end of the inverted U-shaped siphon strap be located above the upper end of the liquid circulation cylinder.

When this electrolytic solution is ejected, the gas accumulated in the gas collection chamber 2 and the gas in the siphon strap 3 are suddenly discharged to the outside in a state of one trap.

If there is no rib for dividing the gas in the gas collection chamber 2, most of the gas accumulated in the gas collection chamber 2 will come out by one pumping of the electrolyte. For this reason, the amount of gas used is large relative to the amount of electrolyte pumped up once, and the stirring efficiency is extremely low.

In the present invention, for the above reason, the shape of the gas collection chamber 2 is devised and the ribs are provided so that the electrolyte can be pumped up once with a minimum required amount of gas. This is because the gas collected by the vertical ribs 6 provided in the gas collection chamber 2 is completely divided, and the gas accumulated by the horizontal ribs 7 does not flow into the siphon strap 3 because of a constant amount. To do so. Since the horizontal rib 7 is as low as about 1 mm in height, the accumulated gas starts to flow when it reaches a certain amount.
Further, since the position of the horizontal rib 7 is inside the vertical rib 6 from the position where the vertical rib 6 is cut before the siphon strap 3, the gas stops there. This prevents the vertical ribs 6 from becoming one lump at the cut end. Further, the number of horizontal ribs 7 can be set depending on the size of the collection chamber 2 so that the amount of gas flowing into the siphon strap 3 can be made constant.

When this transitional state ends, the state shown in FIG. 3C is reached and stabilized, and gas accumulation starts again.

Since the specific gravity ρ ₀ of the upper electrolyte outside the liquid circulation cylinder 1 is lighter than the specific gravity ρ inside the liquid circulation cylinder, the electrolyte surface that has entered the gas collection chamber side 3b of the siphon strap 3 is greater than the liquid surface inside the liquid circulation cylinder 1. Stationary at a high position. At this time, unless the upper end of the liquid circulation cylinder 1 is covered with the gas reservoir 5, the upper electrolyte having a low specific gravity enters from the upper end of the liquid circulation cylinder. If the upper electrolyte is mixed in the liquid circulation cylinder, the stirring efficiency of the present apparatus will be significantly reduced, as will be described later.

The larger the volume of the gas reservoir 5 is, the greater the blocking effect is. When this volume is small, when the electrolytic solution is ejected from the liquid circulation tube, the residual gas in the gas reservoir 5 is also discharged, and at that moment, the upper electrolytic solution is discharged. It may enter the liquid circulation cylinder. When the inner diameter of this portion is reduced, the surface tension in the gap between the portions increases, and when the generated gas enters the liquid circulation cylinder 1 through the small holes 4 through the siphon strap 3, the surface tension is equal to the surface tension. A water head (pressure) is required, and it is necessary to increase the height difference between the lower end of the gas collection chamber and the small hole position. If this is mistaken, the generated gas will escape from the lower end of the gas collection chamber. For this reason, it is desirable to make the inner cross-sectional area S of the gas reservoir 5 sufficiently larger than the inner cross-sectional area s of the liquid circulation cylinder. By providing the gas reservoir 5, a stable stirring effect can be obtained regardless of the position of the electrolyte surface.

The pressure balance in the gas reservoir of Figure 3 A _{is, (hy + H 3) ρ} = (H 1 -H 2 + H 3) ρ 0 + Δp2 ... (2) (1), when obtaining the hx equation (2), hx = [Δp1 + 2Δp2− (ρ−ρ ₀ ) H ₃ ] / ρ ₀ (3) As can be understood from the formula (3), the maximum value of hx is when ρ = ρ ₀ , and the small holes are 4 parts. Since the surface tension Δp1 generated at 1 and the surface tension Δp2 generated at the lower end of the gas reservoir 5 ensure a sufficient gas passage, a gap is provided so that the water head value of this surface tension is 2-3 mm or less. . For example, Δp
1 + Δp2 ≈ 5 mm (water head value) and the specific gravity of the electrolyte is ρ ₀ ≈ 1.2
Then, when hx = 4 to 5 mm, the gas in the inverted U-shaped siphon strap 3 enters the upper liquid circulation cylinder 1a and discharges the sulfuric acid in the cylinder 1a to the outside of the cylinder. This state is shown in FIG. 3B.

As described above, when the specific gravities inside and outside the cylinder 1 are equal, the vapor phase surface (a) decreases to the bottom, but when ρ >> ρ ₀ (3)
As can be understood from the equation, hx becomes negative and the vapor phase surface (a) is above the small hole 4. The reason why the generated gas can enter the small holes 4 in this state is that the value of hy decreases as the value of ρ increases, as can be understood from the equation (2). In other words, the electrolytic solution surface in the upper liquid circulation cylinder 1a gradually decreases due to the increase in the specific gravity value ρ, and when the difference in the specific gravity between ρ and ρ ₀ exceeds a certain value, hy <0, and the electrolytic solution inside the upper liquid circulation cylinder 1a is electrolyzed. A condition occurs in which there is no liquid. In this state, the vapor phase surface (a) rises to near the uppermost part of the inverted U-shaped siphon strap, and the generated gas freely passes through the small holes 4 inside the upper liquid circulation cylinder 1a and is discharged outside the cylinder.

In this way, the amount of electrolyte lifted by the stirrer (stirring capacity)
Is proportional to hx, and when hx exceeds a certain value (ρ−ρ ₀ ), hx becomes negative and the stirring ability is lost as described above.

As can be understood from Eq. (2), the larger the value of (H ₁ -H ₂ ) is, the larger hy becomes, and the higher the stirring capacity and hx become, the larger the value, the higher the height of the stirrer. Become.

Although electrolyte push amount enough to take inner cross-sectional area greater in the upper circulation tube 1a is increased, the inner cross-sectional area is 60 to 80 mm ²
If it exceeds, the substitution phenomenon of the electrolyte and gas occurs in the cylinder 1a,
Stirring ability decreases.

Besides, the smaller the inner volume of the inverted U-shaped siphon strap 3 is, the more the amount of pushing up the electrolytic solution with respect to the amount of generated gas is increased, but as the water film is formed in the siphon strap 3, 3a, 3b
When narrowing the gas passage parts, (3) the .DELTA.p1 + .DELTA.p2 surface tension of Δp3 occurs in addition, hx is rapidly increased hx> H ₄ and the generated gas is generated from the stirrer gas collecting chamber 2 lower part The gas escapes and the stirrer fails.

FIG. 3B is a diagram showing an excessive state immediately after the generated gas enters the upper liquid circulation cylinder 1a through the small holes 4 and the electrolytic solution in the cylinder is discharged to the outside of the cylinder. The pressure distribution in this transient state is analyzed by a mathematical formula as follows.

As shown in FIG. 3B, Δp1 and Δp2 in the equation (1) can be ignored because the electrolyte is not present in the upper liquid circulation cylinder and the pressure inside the siphon strap is reduced. hx the equation = - a (H ₁ -H _2). That is, the vapor phase surface (a) on the siphon strap 3b side rises to the tip of the cylinder 1a. At this time, the upper opening 6 of the gas collection chamber and the small hole 4 are not connected by the inverted U-shaped siphon strap 3, but if the upper opening of the gas collection chamber and the small hole 4 are directly connected, the specific gravity of the upper part of the battery is low. The electrolytic solution ρ ₀ does not flow into the liquid circulation cylinder through the small hole 4 and does not push up the electrolytic solution ρ having a high specific gravity at the lower end of the cylinder. As described above, the most important point in the present invention is the adoption of the inverted U-shaped siphon strap, and the gas is siphon strap 3b.
Although it can move freely to the 3a side, the movement of the electrolytic solution is completely blocked by this siphon strap. As described above, in the transient state, the 3b-side vapor phase surface (a) of the inverted U-shaped siphon strap 3 rises to the upper end of the liquid circulation cylinder, so the vertex of the inverted U-shaped siphon strap 3 is above the upper end of the cylinder 1. Is desirable.

In the state of FIG. 3B, the inside of the siphon strap 3 and the inside of the upper liquid circulation cylinder 1a are momentarily slightly depressurized, so that the vapor phase surface (a) rises and at the same time, the electrolysis starts from the lower end of the gas reservoir. Liquid tries to enter the upper liquid circulation cylinder,
A film of surface tension exerts a pressure of −Δp2 on the lower end of the gas reservoir, and prevents the electrolytic solution from flowing back into the cylinder 1a. Therefore, even if the stirrer is submerged in water, the lower electrolyte can be pushed up without mixing the electrolyte having a low specific gravity in the upper part of the battery into the cylinder 1a.

FIG. 3C shows a stable state diagram in which the excessive state in FIG. 3B has passed and the electrolytic solution ρ having a higher specific gravity than the bottom of the battery case is pushed up through the liquid circulation tube and is stable. The inverted U-shaped siphon When the generated gas is accumulated in the strap 3, the state returns to the state shown in FIG. 3A.

A liquid stirring battery having the liquid stirring device shown in FIGS. 1 and 2 attached to a battery for a battery forklift, a liquid stirring battery using a gas collection chamber without ribs, and a normal liquid stirring device without liquid stirring device. Fig. 4 shows the increase in the specific gravity of the electrolyte when the battery C and a normally used quasi-constant voltage charger were discharged after 100% discharge. In the case of normal battery C, the charge amount is about 120% after 10 hours of charging, and the electrolyte specific gravity has risen to the specified value of 1,280. The liquid stirring battery (B) had a charging time of 9 hours and a charged amount of about 114%, and the specific gravity of the electrolytic solution had risen to a specified value.

On the other hand, the liquid-stirred battery a has a charging time of 8 hours and a charging amount of about
At 0%, the electrolyte specific gravity has risen to the specified value.

As described above, the battery equipped with the liquid stirring device according to the present invention has an overcharge amount of about half and can complete the charge amount.

Effects of the Invention The device of the present invention has the structure as described above,
It is possible to configure the electrolytic solution stirring device to be extremely compact, and the gas collection chamber arranged above the electrode plate group may have any shape as long as it can collect a part of the gas generated in the electrode plate group. It is also possible to use a gas reservoir, and by providing a gas reservoir at the upper end of the liquid circulation cylinder, the stirring effect does not deteriorate regardless of the position of the upper end of the liquid circulation cylinder in the electrolytic solution.

Further, by providing the ribs in the gas collection chamber, the stirring efficiency is improved and the vertical specific gravity of the electrolytic solution is made uniform when the charge amount is small. This eliminates the need for 20% or more overcharging as in the past. The effect is shown in FIG.

Also, the liquid circulation cylinder that sucks up the electrolyte has an inner diameter of 2 to 3 mm.
Since the degree is sufficient, it can be inserted into any gap in the battery, and is highly practical, such as being applicable to any storage battery.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a storage battery equipped with the electrolytic solution stirring device of the present invention, FIG. 2 is a partially cutaway perspective view of the electrolytic solution stirring device, and FIGS. 3A to 3C are electrolytic solution stirring of the present invention. FIG. 4 is a diagram illustrating the operation of a storage battery equipped with a device, and FIG. 4 is a result of comparison between the device of the present invention and an electrolyte stirring device without ribs, and a conventional battery without a stirring device, which are experimental. A ... Battery case, B ... Electrode plate group, C ... Electrolyte solution, D ... Electrolyte stirring device, 1 ... Liquid circulation tube, 2 ... Gas collection chamber, 3 ...
… Inverted U-shaped siphon strap, 4 …… Small hole, 5 …… Gas reservoir, 6 …… Vertical rib, 7 …… Horizontal rib

Claims (1)

[Claims] 1. An electrode plate group having a small hole in an intermediate portion, a liquid circulating cylinder vertically arranged in an electrolytic solution, and a lower end opening below a small hole position of the liquid circulating cylinder. An electrolyzer having a gas collection chamber arranged above, connecting the small hole and the gas collection chamber with an inverted U-shaped siphon strap, and providing a gas reservoir at the upper end opening of the liquid circulation cylinder. A storage battery provided with an electrolyte stirring device, wherein a plurality of ribs are provided in the gas collection chamber in the liquid stirring device.