JPS5844750B2 - How to remove waste - Google Patents

Description

[Detailed description of the invention] The present invention is a method for removing waste from a battery case.

In particular, when gas is generated within a battery case, this is a method in which the exhaust gases are extracted as a gas-liquid multiphase flow.

The most common type of battery that generates gas within the battery is the electrolysis of alkali metal chlorides using the diaphragm method, but the present invention is also applicable to other electrolysis such as the electrolysis of mirabilite.

Further, the present invention is a filter press type battery case in which a plurality of unit batteries each having an anode chamber and a cathode chamber are electrically connected in series, and gas and liquid are discharged from these unit batteries in parallel and guided to a common header. Applies to emission methods.

A typical example of such a battery is one for electrolyzing aqueous solutions of alkali metal chlorides, particularly sodium chloride and potassium chloride, using an ion exchange membrane method.

Therefore, the following explanation will mainly be made using an ion exchange membrane method using an alkali metal chloride or sodium chloride aqueous solution electrolytic cell, but the present invention is of course not limited to those using a sodium chloride electrolytic cell.

In a filter press type battery case, a diaphragm such as an ion exchange membrane is generally provided vertically, and an anode chamber containing an anode and a cathode chamber containing a cathode are opposed to each other on both sides to form one unit cell.

In the bipolar type, a plurality of anode chambers and cathode chambers are alternately located with a diaphragm in between, and a DC power source is connected to each end.

In the case of a monopolar type, two electrodes face each other in the anode chamber and two cathodes face each other in the cathode chamber, and each is connected to a power source in parallel.

In these types of batteries, the supply and discharge of liquid and the discharge of raw gas are carried out in parallel to each unit battery through a common header.

Usually, this is done to make the flow of liquid in the unit container uniform.
The liquid is supplied from near the bottom of the battery container and discharged from near the top.

For this reason, the liquid supply header is generally located at the bottom of the battery case, and the discharge header is located at the -E section.

For electrolysis that generates gas, there are two methods: one uses two separate outlets for liquid and gas in each unit cell, and the other uses a single outlet for gas-liquid mixed phase flow.

The former not only becomes more complicated due to the increase in the number of nozzles for the discharge port of the unit cell, but also makes it difficult to achieve sufficient gas-liquid separation within the unit cell, making each unit cell even more complicated due to the gas-liquid separation. It becomes a structure.

On the other hand, when discharging as a gas-liquid mixed flow, this must be led to a tidal gas-liquid separator to recover the gas and liquid separately, and such equipment is required.

In addition, we focused on the fact that if gas-liquid separation is performed in a common header, there is no need to use a separate gas-liquid separation device, and we developed a header for discharging caustic alkali and hydrogen in an alkaline chloride electrolyzer, in which the liquid is separated from one end. There is also a proposal for a method in which hydrogen gas is extracted from the other end (Japanese Patent Application Laid-Open No. 53123397).
).

This method is effective in principle, and may be possible for caustic and hydrogen systems by making the diameter of the header considerably larger than the flow rate.

The problem in this case is that hydrogen gas gets caught in the liquid extraction piping, which makes it difficult to reliably prevent vapor lock in the piping and cavitation in the pump. Is the piping a gas or liquid extraction piping?
The problem is that it is complicated because it is divided into two ends of the battery case.

The present invention, in principle, performs gas-liquid separation within a header, and is a departure from the above-mentioned proposal. This paper proposes a method that can be applied to any gas or liquid system extracted by multiphase flow.

That is, the present invention is a reliable method with no occurrence of vapor lock or cavitation.

That is, the present invention discharges waste discharged as a gas-liquid multiphase flow from a unit container of a filter press type container consisting of a plurality of unit containers into a common header through a discharge conduit, The gas-liquid two-phase flow is created in the header, and when the gas and liquid are taken out separately, the multiphase flow discharged from each unit container is introduced into the gas phase in the header, and the header a portion of, generally enlarged at one end,
This method is characterized in that the cross-sectional area of the liquid phase part is increased, and the liquid is taken out from the bottom of the enlarged part, and the gas is taken out from the earth part of the header.

In the present invention, caustic alkali and hydrogen obtained by ion exchange membrane method, electrolysis of alkali metal chloride, or (
and) In addition to circulation of salt water and extraction of chlorine, extraction of raw materials and product solutions to be treated in electrolytic reactions of organic and inorganic compounds accompanied by low oxygen and hydrogen generation, especially alkali metal chlorides. It is effective for electrolysis, etc.

The size of the enlarged portion of the header in the present invention should be at least twice the average liquid flow portion of the header, and the larger the size, the more effective it is, but from the viewpoint of the device, a size of 5 times or less is sufficient.

In the present invention, the partial enlargement may be either a box-like enlargement or a structure in which the entire area or part of the header is gradually enlarged.

Another feature of the present invention is that the gas-liquid mixed flow supplied from each unit cell must be discharged into the gas phase portion within the header.

Therefore, the conduit from each unit container to the header should be connected above the horizontal diameter of the header, or if connected from the bottom of the header, pass through a nozzle that protrudes above the liquid level in the header. should be released;
The latter method is preferable, especially considering leakage current within the header.

This will be explained below using the drawings.

FIG. 1 shows a conventional gas-liquid separation method.

The battery case 1 is made up of a plurality of unit battery cases 2, with a discharge header 3 located near the top of the container and a liquid supply header 4 located near the bottom.

In the electrolysis of ion-exchange decomposed salt, there are both a supply header and a discharge header for the anode chamber and the cathode chamber, and only one of them is shown in this figure and FIG. 2.

The gas-liquid mixed streams discharged from the unit cells 2 each enter the discharge header 3 through conduits 5 and are further introduced into the gas-liquid separator 8 through conduits 6.

Here, gas and liquid are separated, and the gas is taken out from the pipe 9 and the liquid is taken out from the pipe 10.

In this case, the gas-liquid separator becomes larger and requires a larger space.

FIG. 2 is a drawing explaining the principle of the method of the present invention,
A conduit 5 for guiding a gas-liquid mixed flow is connected from each unit tank 2 (only a part of which is shown) to the waste header 3.
These conduits are discharged into the header from nozzles 11 which penetrate the liquid phase within the header.

By doing this, the gas and liquid are separated, and by making this nozzle an electrically defective conductor, the electrical connection in the liquid between the battery case and the header can be almost completely cut off. Can be done.

One end of the header has an enlarged section 12 in which the liquid flow rate is further reduced to improve gas-liquid separation.

The liquid phase flow is extracted by the extraction piping from near the bottom of the expansion section, but the extraction speed must be maintained until the liquid level in the header drops locally and reaches a height that finally entrains gas. Must be.

Various methods are used for this purpose, and FIG. 2 shows an example in which a liquid level control valve is installed at an appropriate position in the piping.

Furthermore, in this example, the main pipe that collects the liquid taken out from each battery tank for the entire plant is partially provided with a bulge 13 at the top, so that the temperature of the entrained gas or dissolved gas can be adjusted. It is also possible to use a gas reservoir generated by gasification due to a difference, etc., and completely remove the gas in the liquid by the gas vent 14.

Further, although the gas in the header is taken out upward from the gas pipe 15 located at the top, it is also preferable to provide a bulge 16 in the middle to prevent entrainment of droplets.

In particular, droplets of a solution containing dissolved solids may adhere to the pipe wall near the gas pipe inlet and dry, causing solid matter to precipitate and cause clogging. By providing this, the flowing liquid can also have a washing effect.

FIG. 3 shows that as another means of keeping the liquid level in the header constant, a part 17 of the liquid take-out pipe is bent into a figure 8 shape, and a so-called siphon breaker is inserted into the communication pipe 1 from near the top of the pipe.
8, it is connected to the header gas phase section.

This siphon breaker has the function of removing gas present in liquid and piping.

FIG. 4 is a diagram in which one or more weir plates 19 for rectification are provided in the enlarged portion of the header.

(4 pieces in Figure 4). This is preferable because gas is entrained in the liquid, and in particular, fine bubbles are sufficiently separated from the liquid.

In Figures 2 to 4, the gas and liquid extraction positions are both shown as being at one end.In order to prevent entrainment of droplets into the gas and to keep the piping system clean, such an arrangement is recommended. However, it is of course possible to take out both the air and the liquid from other locations, and the present invention is not limited to the embodiments shown in the drawings.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a conventional method for taking out waste from a battery case, FIG. 2 is a diagram showing a method according to the present invention, and FIG. 3 is an enlarged view of the header and liquid removal used in the present invention This is to explain an example of the structure of the piping section, and FIG. 4 is a diagram showing an example in which a rectifying weir plate is provided in the header enlarged section used in the present invention. In these figures, 1 is a battery container, 2 is a unit container, 3 is a discharge header, 5 is a conduit for discharge (air-liquid mixed flow), 6 is a pipe for taking out liquid from the header, and 7 is a liquid level control in the header. 8 is a gas-liquid separator, 11 is a nozzle for discharging the gas-liquid mixed flow from the unit cell into the header, 12 is an enlarged portion of the header, 13 is a gas reservoir provided in the liquid extraction main pipe, 14 15 is a gas extraction pipe from the header, 16 is a droplet separator, 17 is a figure-8 piping section for keeping the header liquid level constant, 18 is for a siphon breaker,
The communication pipes and 19 each represent a weir plate for rectifying liquid in the header.

Claims (1)

[Claims] 1. A system in which waste discharged as a gas-liquid multiphase flow from unit containers of a filter press type container consisting of a plurality of unit containers is discharged into a common header through a discharge conduit. , the gas-liquid two-phase flow is created in the header, and when the gas and liquid are taken out separately, the multiphase flow discharged from each unit container is introduced into the gas phase in the header, and A method for taking out waste, characterized in that a part of the header is enlarged to increase the area of the liquid phase part, liquid is taken out from the bottom of the enlarged part, and gas is taken out from the upper part of the header. 2. The method according to claim 1, wherein the liquid extraction pipe has a control valve for keeping the liquid level in the header constant. 3. Claim 1, characterized in that the liquid extraction pipe is bent in a hundred-figure shape, the top of which is approximately at the same height as the liquid level in the header, and the vicinity of the top communicates with the gas phase in the header. the method of. 4. The method according to claim 1, characterized in that at least one weir is provided in the enlarged portion within the header. 5. The method according to claim 1, wherein the filter press type container is a container for ion exchange membrane electrolysis of alkali metal chlorides. 6 The common header is at a height equal to or higher than the top surface of the battery case, and the gas-liquid multiphase flow introduced from each unit battery case is directed into the header from the bottom to the top, passing through the liquid phase in the header and flowing into the air. The method according to claim 1, wherein the method is discharged from a nozzle projecting into the phase part.