JP2000042530A - Deaerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain stable gas-liquid contact to improve the liquid quality of treated liquid, and furthermore, to obtain the treated liquid having stable liquid quality without lowering gas-liquid contact efficiency even if the feed liquid pressure is lowered. SOLUTION: This deaerator 10 is provided with a spray mechanism 13 arranged in a space in a vessel 11 and for spraying water to be treated from a water supply line 12 to the upper space, a circulating line 18 for making treated water by the spray mechanism 13 merge with water to be treated of the water feeding line 12 from the vessel 11 to circulate it, and a circulating pump 19 arranged in the circulating line 18 to circulate a part of the treated water in the vessel 11 through the circulating line 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a degassing apparatus using gas-liquid contact, and more particularly, to improving the liquid quality of a processing liquid and maintaining a stable liquid quality even when the supply amount decreases. It relates to a possible deaerator.

[0002]

2. Description of the Related Art As a deaerator of this type, for example, a packed tower system, a bubble column system or a spray tower system is known. For example, a decarbonation system of a pure water production system or a trichloroethane in groundwater is used. It is widely used as a water treatment device for removing volatile harmful substances.

[0003] For example, FIG. 3 is a diagram showing a deaerator of a packed tower system. This type of deaerator, as shown in the figure,
A tower body 1, a packed layer 2 in which a filler such as Raschig ring, terraret, or the like is filled in the tower body 1, a sprinkler pipe 3 disposed above the packed layer 2, and a lower part of the packed layer. It is configured as a packed tower having the provided gas supply unit 4. Therefore, for example, when water to be treated in which a gas such as carbon dioxide or a volatile component such as trichlorethylene is dissolved is supplied from the water sprinkling pipe 3 and air is supplied from the gas supply unit 4, the water to be treated becomes solid arrow in FIG. As shown in the figure, the air passes through the packed bed 2 in a downward flow, and the air passes through the packed bed 2 in an upward flow as shown by a dashed arrow in FIG. And other volatile components are removed from the water to be treated. However, since the degassing apparatus has the packed bed 2 and the water sprinkling pipe 3 in the tower main body 1, it has flexibility for gas-liquid load fluctuation and is excellent in degassing efficiency, but has a high tower height and installation space. However, there is a problem that the flooding phenomenon easily occurs.

[0004] In addition, since the bubble tower system is unlikely to cause a flooding phenomenon as in the packed tower system, air is supplied in an excessive amount and air-liquid contact is made as much as possible to improve the quality of treated water. Therefore, the gas-liquid ratio (air / water) needs to be increased because the pressure loss is large and the gas-liquid contact efficiency by air is inferior. Therefore, when using the bubble column system as an alternative to the packed column system, it is necessary to consider a multi-stage treatment. On the other hand, since the spray tower method has a small pressure loss and can achieve good gas-liquid contact with a small energy loss, it is widely used as a gas absorbing device.

[0005]

However, the conventional degassing apparatus has advantages and disadvantages in each case as described above. In particular, in the case of the spray tower system, good gas-liquid contact is achieved with small energy loss. However, when the liquid supply amount (liquid supply pressure) is reduced, there is a problem that the particle diameter of the spray particles becomes unstable and the gas-liquid contact efficiency is reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and can maintain the stable gas-liquid contact to improve the quality of the processing liquid. An object of the present invention is to provide a deaerator capable of obtaining a treatment liquid having a stable liquid quality without lowering the liquid contact efficiency and further simplifying the apparatus.

[0007]

The inventor of the present invention has conducted various studies on the gas-liquid contact and the liquid quality of the processing liquid in each of the packed tower system, bubble column system and spray tower system. It has been found that spraying can always provide spray particles having good gas-liquid contact efficiency even when the supply pressure decreases. Furthermore, it has been found that the gas-liquid contact efficiency can be improved by performing a composite treatment combining the spray tower method and another method.

The present invention has been made based on the above findings, and a degassing apparatus according to claim 1 degass a liquid to be treated,
In a deaerator for removing a dissolved gas and / or a volatile component contained therein to obtain a treatment liquid, a gas feeding means for supplying a deaeration gas into a container; A spray mechanism for spraying the liquid to be treated from the liquid supply pipe into the space and making gas-liquid contact with the gas supplied from the gas supply means; and supplying the processing liquid by the spray mechanism from the container to the space. A circulation pipe that joins and circulates the liquid to be treated in the liquid pipe, and a liquid feeding unit that is disposed in the circulation pipe and that joins a part of the processing liquid in the container to the liquid supply pipe through the circulation pipe. It is characterized by having.

The degassing apparatus according to a second aspect of the present invention degass a liquid to be treated and removes dissolved gas and / or volatile components contained therein to obtain a treatment liquid. A gas supply means for supplying a gas for deaeration into a container, and a gas supply means disposed in a space in the container and spraying a liquid to be treated from a liquid supply pipe into the space. A spray mechanism for bringing the gas supplied from the means into gas-liquid contact, a gas-liquid contact means for bringing the treatment liquid by the spray mechanism into gas-liquid contact with the gas supplied from the gas supply means, and a treatment by the gas-liquid contact means A circulating pipe that joins and circulates the liquid from the container to the liquid to be treated in the liquid supply pipe, and a part of the processing liquid disposed in the circulation pipe and in the container to the liquid supply pipe via the circulation pipe And a liquid feeding means for merging. It is.

According to a third aspect of the present invention, in the degassing apparatus according to the second aspect, the gas-liquid contacting means includes a filling device disposed below the spray mechanism in the container. Characterized in that it is a layer.

According to a fourth aspect of the present invention, in the degassing apparatus according to the second aspect, the gas-liquid contacting means is disposed in the processing liquid stored in the container. The gas supply means is a gas dispersion means for bubbling a gas supplied from the gas supply means into the processing liquid.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in FIGS. FIG. 1 is a conceptual diagram showing one embodiment of the deaerator of the present invention, and FIG. 2 is a conceptual diagram showing another embodiment of the deaerator of the present invention.

The deaerator 10 of the present embodiment is, for example, shown in FIG.
As shown in FIG. 2, a substantially cylindrical container 11, a spray mechanism 13 for subjecting the water to be treated, which is provided in the container 11 and supplied from a water supply pipe 12, to gas-liquid contact in two stages to obtain treated water, It is provided with a packed layer 14 as a gas-liquid contact means, and degass water to be treated, and removes dissolved gases such as carbon dioxide gas and volatile harmful components such as trichloroethane to obtain a treatment liquid.
The vessel 11 includes a tower 11A for treating the water to be treated, and a water storage 11B connected to the lower side of the tower 11A. A plurality of spray nozzles 1 are provided in the upper space of the tower 11A.
A spray mechanism 13 having 3A is provided, and a filling layer 14 made of a filler such as Raschig ring or teralet is formed below the spray mechanism 13. Further, a water supply pump 15 is provided in the water supply pipe 12, and the water supply pump 1 is provided.
When the water to be treated is supplied to the spray mechanism 13 through 5,
The water to be treated is sprayed from the spray mechanism 13 to remove and degas the dissolved gas such as carbon dioxide and / or volatile components contained in the water to be treated by gas-liquid contact with air supplied from the blower 17 described later. I have to do it. Spray mechanism 13
As shown by the dashed arrow in FIG. 1, the treated water is in gas-liquid contact with the surface of the filler while passing through the packed bed 14 in a downward flow to further remove dissolved gas and / or volatile components, and degas. The quality of the treated water can be further improved. In this way, the water treated by the two-stage treatment accumulates in the water storage part 11B.

A blower 17 is connected between the filling layer 14 and the water storage section 11B of the container 11 via an air supply pipe 16, and a container formed between the filling layer 14 and the water storage section 11B from the blower 17 is provided. Air is supplied to a lower space in the inside 11. The air supplied into this lower space is shown in FIG.
And passes through the packed bed 14 in ascending flow as shown by the white arrow. Air rises through the packed bed 14 while the spray mechanism 13
Gas-liquid contact with the treated water by the spraying process, and further gas-liquid contact with the spray water by the spray mechanism 13, followed by the dissolved gas and / or volatile components removed from the exhaust port 11 </ b> C formed at the upper end of the container 11. It is leaked.

Further, the water storage section 11B and the water supply pipe 12 are connected via a circulation pipe 18, and a part of the treated water in the water storage section 11B (for example, equivalent to 40% of the supply amount of the water to be treated).
Is returned to the water supply pipe 12 via a circulation pump 19 disposed in the circulation pipe 18 and is combined with the water to be treated.
The internal water pressure is raised. Therefore, the spray mechanism 13 is supplied with a water amount 1.4 times the water supply amount, and the water supply pressure passing through the spray mechanism 13 is equal to 1.
4 times. Further, a pressure gauge 20 is provided in the water supply pipe 12, and the water pressure in the water supply pipe 12 is monitored by the pressure gauge 20, and when the water pressure falls below a predetermined value, the pressure gauge 20 is provided.
The signal (indicated by a dashed line in FIG. 1) 21 controls the circulation pump 19 of the circulation pipe 18 to increase the circulation flow rate and return the water pressure in the water supply pipe 12 to a predetermined value.

Therefore, since a part of the treated water returns to the water supply pipe 12 to increase the water pressure, the water supply pressure in the spray mechanism 12 is maintained at a predetermined value even if the supply amount of the treated water is reduced, and the spray water is maintained. Can be kept small, and 40% of the treated water can be degassed again in the spray mechanism 13 and the packed bed 14, so that the quality of the treated water can be further improved.
Moreover, since the water supply pressure in the water supply pipe 12 is always maintained at a predetermined value via the pressure gauge 20, the particle diameter of the spray water from the spray mechanism 13 is maintained constant, and stable gas-liquid contact is achieved. It can be carried out. Further, a water supply pipe 22 is connected to the water storage section 11B, and the treated water accumulated in the water storage section 11B is supplied from the water supply pipe 22 via a water supply pump 23 provided in the water supply pipe 22.

Next, the operation will be described with reference to FIG. When the water supply pump 15 is driven, the water to be treated reaches the spray mechanism 13 via the water supply pipe 12, and the water to be treated is sprayed from the spray mechanism 13. At the same time, the blower 17 is driven, and the air flows into the lower space in the container 11 through the air supply pipe 16 and passes through the packed bed 14 by ascending flow as shown by a white arrow in FIG. Reach In the upper space, the water to be treated sprayed from the spray mechanism 13 comes into gas-liquid contact with the air that has passed through the filling layer 14, and a dissolved gas such as carbon dioxide gas is degassed from the water to be treated and sprayed over the entire upper surface of the filling layer 14. You. On the other hand, the dissolved gas removed from the water to be treated is exhausted from the exhaust port 11C together with the air.

The treated water of the spray mechanism 13 which has been subjected to the first-stage deaeration treatment as described above, passes through the packed bed 14 in a downward flow as shown by the dashed arrow in FIG. 14 comes into gas-liquid contact with the air passing through
The dissolved gas remaining in the treated water is further degassed by gas-liquid contact with the rising air, and is stored in the water storage portion 11B in the container 11. Part of the treated water in the water storage section 11B (corresponding to 40% of the supply amount of the treated water) joins the treated water supply pipe 12 from the circulation pipe 18 via the circulation pump 19, and is sprayed together with the treated water. The dissolved gas is further degassed in the mechanism 13 and the packed bed 14. Further, even if the supply amount of the water to be treated decreases, the pressure gauge 20 operates to increase the circulating water amount by the circulating pump 19, maintain the water pressure in the spray mechanism 13 at a predetermined value, and spray the water from the spray mechanism 13. Stabilizes the particle size of water and provides stable gas-liquid contact. The treated water stored in the water storage section 11 </ b> B is sent from the water pipe 22 through the water pump 23.

As described above, according to the present embodiment,
After the water to be treated supplied from the water supply pipe 12 is sprayed by the spray mechanism 13 in the upper space in the container 11 to make gas-liquid contact, the treated water is subjected to the second gas-liquid contact in the filling layer 14. Is stored in the water storage unit 11B, and a part of the treated water in the water storage unit 11B is returned from the circulation pipe 18 to the water supply pipe 12 via the circulation pump 19 to be combined with the water to be treated. The spray mechanism 13 and the packed bed 14 undergo a two-stage degassing process, and 40% of the treated water undergoes a further two-stage degassing process. Water quality is improved,
It is possible to obtain treated water having stable water quality. In addition, 40% of the treated water is combined with the water to be treated to form
Since the pressure of the passing water can be maintained at a high pressure state, the particle size of the spray water in the spray mechanism 13 becomes fine even if the supply amount of the water to be treated is reduced, so that sufficient gas-liquid Contact can be established.

Further, according to the present embodiment, one container 1
Since the water to be treated passes through the spray mechanism 13 and the packed bed 14 in each one a plurality of times, and is subjected to multi-stage treatment, the multi-stage treatment is simplified. Can be reduced. In addition, since fluctuations in the amount of water to be treated can be handled by controlling the circulation pump 19, operation management is easy and running costs can be reduced.

The deaerator 30 shown in FIG. 2 includes a container 31, a water supply pipe 32, a spray mechanism 33, a diffuser mechanism 34, a water supply pump 35, a supply pipe 36, a blower 37, a circulation pipe 38,
A circulation pump 39, a pressure gauge 40, a water supply pipe 42, and a water supply pump 43 are provided.
The configuration is the same as that of the above embodiment, except that the air diffusing mechanism 34 is provided in 1.

Therefore, in the present embodiment, the water supply pump 35
Is driven, the water to be treated reaches the spray mechanism 33 via the water supply pipe 32, and the water to be treated is sprayed from the spray mechanism 33. At the same time, the blower 37 is driven, and the air is supplied with fine air bubbles from the air diffusing mechanism 34 at the bottom of the container 31 through the air supply pipe 36 and rises while contacting the stored water in the container 31 with the gas-liquid. Reaches the upper space in the container 31. In the upper space, the water sprayed from the spray mechanism 33 and the air passing through the stored water come into gas-liquid contact, and the water to be treated is stored in the container 31 after the dissolved gas such as carbon dioxide is degassed.
On the other hand, the dissolved gas removed from the water to be treated is exhausted from the exhaust port 31C together with the air. As described above, the water to be treated is subjected to the first deaeration treatment by the spray mechanism 33, and is then subjected to the second deaeration treatment by the diffusion mechanism 34 as stored water in the container 31.

A part of the water stored in the container 31 (for example, equivalent to 40% of the amount of water to be treated) is circulated from a circulation pipe 38 via a circulation pump 39 to a water supply pipe 32 for the water to be treated. The dissolved gas is further degassed in the spray mechanism 33 and the air diffusing mechanism 34 together with the water. Even if the amount of water supplied by the water supply pump 35 decreases due to the decrease in the amount of water supply, the pressure gauge 4
With the signal 41 based on 0, the circulation amount by the circulation pump 39 increases, the water pressure in the spray mechanism 33 is maintained at a predetermined value,
The particle diameter of the spray water from the spray mechanism 33 is always kept small, and a stable deaeration process is performed.

According to the present embodiment as described above,
After the water to be treated supplied from the water supply pipe 32 is sprayed by the spray mechanism 33 in the upper space in the container 31 to make gas-liquid contact and perform the first deaeration treatment, the treated water is diffused as stored water. A second deaeration process is performed by bringing the bubbles from the mechanism 34 into gas-liquid contact, and a part of the treated water is returned from the circulation pipe 38 to the water supply pipe 32 via the circulation pump 39.
Since the water to be treated is merged with the water to be treated, the water to be treated is subjected to a plurality of deaeration treatments by the spray mechanism 33 and the air diffusing mechanism 34, respectively, and substantially the same operation and effect as in the above embodiment can be expected. .

In each of the above-described embodiments, the case where the spray mechanism is provided at the front stage as the gas-liquid contact means and the packed layer or the air diffusing mechanism is provided at the rear stage has been described. The mechanism may be only a mechanism, and the point is that the present invention is included in a deaerator that is configured to return the treated water by the spray mechanism to the treated water side through the circulation pipe. In each of the above embodiments, the case where a part of the treated water is constantly circulated has been described. However, the pressure of the pressure gauge 20 or the pressure gauge 40 is monitored, and when the pressure falls below a predetermined value, 15 or water supply pump 35
The circulation of the treated water may be performed only when the supply amount of the treated water is reduced.

[0026]

According to the first to fourth aspects of the present invention, the quality of the processing liquid can be improved while maintaining stable gas-liquid contact, and the supply pressure is reduced. Thus, a processing liquid having a stable liquid quality can be obtained without lowering the gas-liquid contacting efficiency, and further, a deaerator capable of simplifying the apparatus can be provided.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing one embodiment of a deaerator of the present invention.

FIG. 2 is a conceptual diagram showing another embodiment of the deaerator of the present invention.

FIG. 3 is a conceptual diagram showing an example of a conventional deaerator.

[Explanation of symbols]

 10, 30 Degassing device 11, 31 Container 13, 33 Spray mechanism 14 Packing layer (gas-liquid contact means) 17, 37 Blower (gas supply means) 18, 38 Circulation pipe 19, 39 Circulation pump (liquid supply means) 34 Aeration mechanism (gas dispersion means)

Claims (4)

[Claims] 1. A degassing apparatus for degassing a liquid to be treated and removing a dissolved gas and / or a volatile component contained therein to obtain a treatment liquid, wherein a gas for degassing is supplied into a container. A gas supply means for supplying a gas to be supplied from the gas supply means, and a spray mechanism disposed in the space in the container and spraying a liquid to be treated from a liquid supply pipe into the space to make gas-liquid contact with the gas supplied from the gas supply means. A circulation pipe that joins and circulates the processing liquid from the container to the liquid to be processed in the liquid supply pipe from the container, and a part of the processing liquid disposed in the circulation pipe and in the container through the circulation pipe. And a liquid supply means for joining the liquid supply pipe to the liquid supply pipe. 2. A degassing apparatus for degassing a liquid to be treated and removing a dissolved gas and / or a volatile component contained therein to obtain a treatment liquid, wherein a gas for degassing is supplied into a container. A gas supply means for supplying a gas to be supplied from the gas supply means, and a spray mechanism disposed in the space in the container and spraying a liquid to be treated from a liquid supply pipe into the space to make gas-liquid contact with the gas supplied from the gas supply means. Gas-liquid contacting means for bringing the processing liquid by the spray mechanism into gas-liquid contact with the gas supplied from the gas feeding means,
A circulating pipe for joining and circulating the processing liquid from the container to the liquid to be processed in the liquid supply pipe from the container, and a circulating pipe disposed in the circulating pipe and passing a part of the processing liquid in the container. And a liquid supply means for joining the liquid supply pipe through the liquid supply pipe. 3. The degassing device according to claim 2, wherein the gas-liquid contact means is a packed bed disposed below the spray mechanism in the container. 4. The gas-liquid contacting means is a gas dispersing means disposed in the processing liquid stored in the container and for bubbling a gas supplied from the gas supply means into the processing liquid. The degassing device according to claim 2, characterized in that: