JP2000229237A - Liquid chemical supply unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small sized and compact liquid chemical supply unit which unnecessitates a measuring tank of the liquid chemical supply unit and is capable of automatically and quantitatively supplying a desired amount of a liquid chemical. SOLUTION: A chemical storage tank 1A, a water supply piping 3 having a liquid chemical injection part 8 and a chemical supply piping 2 for supplying the liquid chemical in the liquid chemical storage tank 1A to the liquid chemical injection part 8 are arranged. A fixed delivery pump P and/or a fixed flow rate valve 5, a liquid chemical flowmeter 6 for detecting an integrated flow rate and a stop valve V1 on its downstream side are provided at the liquid chemical supply piping 2, and the liquid chemical of a prescribed flow rate is automatically injected to the liquid chemical injection part 8 till the liquid chemical reaches a prescribed integrated flow rate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical solution supply device for mixing a chemical solution in a storage tank with service water and supplying the same, and more particularly, to a small and compact device capable of automatically and quantitatively supplying a desired amount of a chemical solution. The present invention relates to a chemical supply device.

[0002]

2. Description of the Related Art In regenerating an ion exchange resin, a concentrated acid (35% hydrochloric acid or 62.5% sulfuric acid) or an alkali (25% aqueous sodium hydroxide solution) is diluted to a predetermined concentration with service water to perform ion exchange. A regeneration step of passing the liquid through the tower for a predetermined time;
The subsequent extruding step with water and the washing step are performed.

FIG. 3 is a schematic sectional view showing a conventional chemical supply device used for such a regeneration process. In this chemical supply device, the concentrated chemical in the chemical storage tank 21 is pumped by the pump 2.
2 to the measuring tank 23. The delivery of this chemical is
Until the level meter 24 in the measuring tank 23 detects that the liquid level in the tank has risen to a predetermined height, the pump 22 and the valve 2
5 is performed. After a predetermined amount of the chemical is supplied to the measuring tank 23, the valve 26 is opened, and the chemical in the measuring tank 23 is sucked by an ejector 28 provided in a supply pipe for the water which is quantitatively supplied by a flow meter 27. After being diluted with water, the solution is passed through an ion exchange tower 29 to perform a regeneration treatment. The suction of the chemical by the ejector 28 is performed by the measuring tank 23.
Is performed until the liquid level falls to a predetermined height. Thereafter, the valve 26 is closed, and only the service water is passed through the ion exchange tower 29 to be pushed out and washed with water. After the end of the extruding and washing steps, the valve 30 is closed and the supply of the water is stopped. Reference numeral 31 denotes a sequencer for controlling the opening and closing of these valves.

The chemical storage tank 21 and the measuring tank 23 and their peripheral devices are provided to prevent the leakage of the chemical into the surrounding environment when the chemical leaks due to an accident or an abnormality. It is stored in the barrier walls 32, 33.

[0005] The chemical storage tank 21 and the measuring tank 23 are provided with degassing pipes 21A and 23A in order to stably and smoothly supply and discharge the chemical while keeping the inside of the tank at atmospheric pressure. When hydrochloric acid is used as a chemical, hydrochloric acid fume is generated in the gas vent pipes 21A and 23A. Therefore, the tip of the gas vent pipes 21A and 23A is connected to a scrubber (gas washing tower) (not shown), It is configured to capture fumes.

[0006]

The conventional chemical liquid supply apparatus shown in FIG. 3 has the following problems because a measuring tank is required.

A space for installing a measuring tank is required,
The equipment becomes larger. Although this measuring tank depends on the amount of ion-exchange resin in the ion exchange tower, one regenerating process usually requires about 1 kiloliter of a chemical solution. Therefore, a measuring tank having a capacity corresponding to them is required. In addition, since a barrier is required to accommodate the measuring tank, a larger space is required.When hydrochloric acid is supplied as a chemical, and when the chemical storage tank and the measuring tank are not in close proximity, A scrubber is required for each of the tanks, and this also increases the number of members and the size of the equipment. In order to supply the chemical solution in the measuring tank at a constant flow rate to the ejector, a specially designed ejector that sucks a predetermined amount by the ejector is required. Various devices such as a level meter and an automatic valve opening / closing mechanism are required in the measuring tank for measuring management. Regeneration of new ion-exchange resin requires several times the amount of chemical solution required for regeneration of normal used ion-exchange resin.However, in the case of using a measuring tank, one measuring capacity is the capacity of the measuring tank. When the chemical solution is required several times in amount, the chemical solution is supplied in several batches for each measurement batch, and the chemical solution is intermittently supplied. I can't. A measuring step of supplying a chemical from the chemical storage tank to the measuring tank;
This requires two steps, that is, a step of supplying the chemical solution by sucking the chemical solution in the measuring tank by the ejector, and a large time loss is required.

The present invention solves the problems of the above-mentioned conventional chemical liquid supply apparatus, and is a chemical liquid supply apparatus which does not require a measuring tank, and which is capable of automatically and quantitatively supplying a desired amount of a chemical liquid. It is an object of the present invention to provide a chemical liquid supply device.

[0009]

According to the present invention, there is provided a chemical solution supply device comprising: a chemical solution storage tank; a water supply pipe having a chemical solution injection section;
What is claimed is: 1. A chemical liquid supply device comprising: a chemical liquid supply pipe for supplying a chemical liquid in a chemical liquid storage tank to said chemical liquid injection section, wherein said chemical liquid supply pipe has a metering pump and / or a constant flow valve and a flow meter for detecting an integrated flow rate. And an on-off valve located downstream of the flow meter.

In the chemical supply apparatus of the present invention, the measurement liquid is not provided, and the chemical liquid in the chemical storage tank is directly supplied to the metering pump and / or the constant flow valve and the flow meter for detecting the integrated flow rate, and the opening / closing valve on the downstream side thereof. The conventional problem caused by providing a measuring tank for injecting into the service water supply pipe is solved, and a small and compact chemical solution supply device is provided.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 are schematic sectional views showing an embodiment of a chemical solution supply device according to the present invention. In FIGS. 1 and 2, members having the same function are denoted by the same reference numerals.

The chemical liquid supply apparatus shown in FIG. 1 sends an acid in an acid storage tank 1A for storing an acid (such as 35% hydrochloric acid or 62.5% sulfuric acid) as a chemical liquid through a chemical liquid supply pipe 2 to supply water. This is a chemical liquid supply device for regenerating the cation exchange resin of the cation exchange tower 4A by diluting it with service water (pure water) supplied from the pipe 3.

[0014] chemical supply pipe 2, a pump (metering pump in this embodiment) P, constant flow valve 5, the drug solution flow meter 6 and the on-off valve V ₁ is provided.

A water supply pipe 3 has a flow meter 7, a chemical liquid injection section 8 such as a line mixer or an ejector, and an on-off valve V
_Two are provided.

The acid storage tank 1A is provided with a degassing pipe 1a as in the case of the conventional chemical liquid supply device. When the acid is hydrochloric acid, the gas degassing pipe 1a is used to capture the hydrochloric acid fume. The outflow end is configured to open to the scrubber 9.

Reference numeral 10 denotes a sequencer to which a measurement result of the chemical liquid flow meter 6 is input, and which outputs instructions to the pump P and the on-off valves V ₁ and V ₂ .

Reference numeral 20 denotes a barrier embankment, which is a chemical supply section, that is, an acid storage tank 1A, in order to prevent an outflow accident due to leakage of the chemical.
And a scrubber 9, a constant flow valve 5, a chemical liquid flow meter 6, a chemical liquid injection part 8, and the like, for storing a portion through which the chemical liquid flows. This barrier wall 20 is provided with chemical resistance by chemical paint painting or the like.

In this chemical liquid supply apparatus, after the water is supplied to the water supply pipe 3, the valves V ₁ and V ₂ are turned on by the sequencer 10 instructing the start of chemical injection (for example, injection of the regenerant into the cation exchange column 4A). At the same time, the pump P is operated and the chemical is supplied to the chemical supply pipe 2.

The water is supplied at a constant flow rate through the water supply pipe 3 by monitoring with a flow meter 7. On the other hand, the acid in the acid storage tank 1A is supplied at a predetermined constant flow rate by the metering pump P and the constant flow valve 5, injected into the chemical liquid injection section 8, and mixed with the water. The integrated amount of the delivered chemical is measured by the chemical flow meter 6, and the measured value is input to the sequencer 10. Then, the supply of the chemical is continued until the integrated flow reaches the required chemical amount (for example, the amount of acid required for one regeneration process), and the time when the integrated flow reaches the required chemical amount in valve V ₁ with the pump P is stopped is closed by an instruction sequencer 10, the chemical liquid supply is stopped. For this reason, during the supply period of the chemical solution, a constant flow rate of the water is mixed with a constant flow of the acid, and the cation exchange resin is regenerated with an acid aqueous solution of a predetermined concentration. Then, after the required amount of acid is supplied, the supply of the acid is automatically stopped.

The supply of the water may be stopped simultaneously with the stop of the supply of the acid. However, in general, the regeneration of the ion exchange resin is continuously performed after the completion of the regeneration step using a chemical solution as a regenerant. for carrying out the extrusion process and water washing step, further performing extrusion and washed by continuous water supply of water but also the valve V ₂ after completion of these steps so as to end the series of reproduction processes in a closed good.

The chemical supply apparatus shown in FIG. 2 supplies alkali from an alkaline storage tank 1B for storing alkali (25% aqueous sodium hydroxide solution) as a chemical through a chemical supply pipe 2 and supplies it from a water supply pipe 3. Irrigation water (pure water)
This is a chemical liquid supply device for regenerating the anion exchange resin of the anion exchange tower 4B after dilution with the above.

This chemical liquid supply apparatus differs from the chemical liquid supply apparatus shown in FIG. 1 in that a scrubber is not connected to the gas vent pipe 1b of the alkaline storage tank 1B and a heat exchanger 11 is provided in the water supply pipe 3. Otherwise, the other configuration is the same. That is, with sodium hydroxide, there is no problem of fume generation at the tip of the degassing tube 1b, so that a scrubber is unnecessary. In addition, when an aqueous sodium hydroxide solution is generally used as a regenerant for an anion exchange resin, the regeneration efficiency can be increased by using the heated solution, so that a heat exchanger 11 for heating the service water is provided in the service water supply pipe 3. Is provided.

In this chemical supply apparatus, as in the case of the chemical supply apparatus shown in FIG.
Injection of the regenerant into the anion exchange tower 4B), the valves V ₁ ,
Together are V ₂ are opened, the pump P is operated, chemical and water are each supplied at a constant flow rate in the chemical supply pipe 2 and the water supply pipe 3. Then, the supply of the chemical is continued until the integrated flow rate of the chemical reaches the required chemical amount (for example, the amount of alkali required for one regeneration process), and the integrated flow reaches the required chemical amount. time valve V ₁ with the pump P is stopped by the instruction of the sequencer 10 is closed, the chemical supply is stopped. For this reason, during the supply period of the chemical solution, a fixed flow rate of alkali is mixed with a fixed flow rate of water, and the anion exchange resin is regenerated with an alkali aqueous solution of a predetermined concentration. Then, after the required amount of alkali is supplied, the supply of alkali is automatically stopped. After stopping the supply of the alkali, if necessary by supplying only water was carried extrusion and washed with water, the valve V ₂ and ends the series of reproduction processes in a closed after the end of these steps.

In the present invention, the chemical solution injecting section 8
A line mixer or an ejector can be employed. The ejector only needs to suck the chemical solution and mix it with the water, and does not need to be a specially designed ejector that adjusts the suction speed unlike a conventional ejector.

As the chemical supply pump P, any pump capable of supplying a chemical to the chemical injection part 8 of the service water supply pipe 3 may be used, and a pump having an arbitrary head capacity according to the configuration of the chemical injection part 8 can be used. . When the chemical liquid injection section 8 is a line mixer, it is necessary to make the pressure higher than the pressure of the service water flowing through the service water supply pipe 3, and therefore, it is preferable to use one having a head of 30 m. Further, when the chemical liquid injection section 8 is an ejector, the liquid can be supplied by a suction force based on the flow of the water in the chemical liquid supply pipe 3, so that a 10 m head may be used.

As the chemical liquid flow meter 6, an integrating flow meter is preferable, and in particular, it is preferable to use an integrating instantaneous flow meter that can check the flow rate and can immediately adjust the flow rate according to the excess or deficiency of the liquid sending amount. The measurement method of this flowmeter may be any of an area type such as an ultrasonic type and a float type or a volume type, or a differential pressure type.

Equipment such as the chemical flow meter 6 and the constant flow valve 5 having a surface in direct contact with the chemical is coated with a PVC coating, a rubber coating or a Teflon coating on the liquid contact surface to impart resistance to the chemical. Use things.

The chemical liquid supply device shown in FIGS. 1 and 2 shows an embodiment of the chemical liquid supply device of the present invention, and the present invention is not limited to the illustrated one unless it exceeds the gist thereof. is not.

For example, in FIGS. 1 and 2, a constant-quantity pump P and a constant flow valve 5 are provided in the chemical supply pipe 2 for the constant supply of the chemical, but only one of them is provided. Is also good. However, in order to more reliably supply the chemical at a predetermined flow rate, it is preferable to provide both a constant flow pump and a constant flow valve as shown in the figure.

In the chemical liquid supply apparatus shown in FIGS. 1 and 2, a return pipe 13 having a back pressure valve 12 is provided in the chemical liquid supply pipe 2. The back pressure valve 12 and the return pipe 13 are not always required, but by adopting such a configuration, when the pump P is driven while the on-off valves V ₁ and V ₂ are closed due to some abnormality. The chemical solution fed by the pump P from the back pressure valve 12 through means such as pressure detection can be returned to the acid storage tank 1A or the alkali storage tank 1B via the pipe 13, thereby preventing an accident.

Such a chemical solution supply apparatus of the present invention uses an ion exchange resin of various ion exchange apparatuses such as a cation exchange tower or an anion exchange tower of a multi-bed column ion exchange desalination apparatus, or a mixed bed pure water apparatus. It is suitable as a chemical liquid supply device used when performing a regeneration treatment with an acid or an alkali, but is not limited to this, as a chemical liquid supply device for diluting various concentrated chemical solutions to a predetermined concentration with water and feeding the predetermined amount to a point of use. It is extremely useful industrially.

[0033]

As described above in detail, according to the chemical solution supply device of the present invention, the following effects are achieved by eliminating the need for the measuring tank of the conventional chemical solution supply device, and the device is small and compact. Efficient drug injection can be performed with an inexpensive device.

Since a calculation tank is not required, the required installation space is significantly reduced (about 15 to 30% of the conventional installation space can be reduced). A measuring tank, a level meter, an automatic valve opening / closing mechanism, a specially designed ejector, and the like are not required, and the apparatus cost is reduced (about 30% cost reduction compared to the conventional product). Since the chemical solution in the chemical solution storage tank can be directly sent without the need for the two steps of the measuring step and the liquid sending step, the chemical injection time is reduced. Even when a newer ion exchange resin requires more chemical liquid than usual, such as when regenerating a new ion exchange resin, continuous measurement can be performed simply by changing the liquid sending time without the need to repeat measurement as in the past. .

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a chemical solution supply device of the present invention.

FIG. 2 is a schematic sectional view showing another embodiment of the chemical liquid supply device of the present invention.

FIG. 3 is a schematic cross-sectional view showing a conventional chemical liquid supply device.

[Explanation of symbols]

 Reference Signs List 1A Acid storage tank 1B Alkaline storage tank 2 Chemical supply pipe 3 Water supply pipe 4A Cation exchange tower 4B Anion exchange tower 5 Constant flow valve 6 Chemical liquid flow meter 7 Flow meter 8 Chemical liquid injection unit 9 Scrubber 10 Sequencer 20 Wall embankment

Claims (1)

[Claims] 1. A chemical supply device comprising: a chemical storage tank; a water supply pipe having a chemical injection part; and a chemical supply pipe for supplying a chemical in the chemical storage tank to the chemical injection part. Is a chemical liquid supply device provided with a metering pump and / or a constant flow valve, a flow meter for detecting an integrated flow rate, and an on-off valve located downstream of the flow meter.