JP4357606B2 - Exhaust gas absorber - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exhaust gas absorber that removes a substance to be removed in a gas by an ion exchange method, and a gas treatment method that removes the substance to be removed in a gas using the exhaust gas absorber.
[0002]
[Prior art]
Conventionally, scrubbers have been used to remove substances to be removed such as impurities and contaminants contained in a gas. As such a scrubber, a wet scrubber that sprays a liquid such as water on a gas passing through the main body of the apparatus and absorbs a substance to be removed by the liquid to separate and remove is generally used. However, in recent years, a so-called dry gas scrubber (exhaust gas absorption device), in which a moistened ion exchanger is arranged in the main body and the substance to be removed in the passing gas is removed by ion exchange, has improved operability and processing efficiency. It is attracting attention from the point of.
[0003]
A conventional dry gas scrubber (exhaust gas absorption device) is provided with an ion exchange part that accommodates an ion exchanger in the main body, a gas supply part of a gas to be processed on the upstream side, and a gas discharge part processed on the downstream side Is provided. During normal operation, ion exchange is performed between the substance to be removed and the ion exchanger while the gas introduced from the gas supply part passes through the ion exchange part, and the gas from which the substance to be removed is removed is the gas discharge part. Is discharged from the main body. If the operation is continued for a certain period, the exchange capacity of the ion exchanger decreases, so that the apparatus is temporarily stopped and the regeneration process of the ion exchanger is performed. The regeneration process is performed by flowing the regeneration solution through the ion exchanger, and the ions to be removed that have been chemically adsorbed (ion-bonded) are removed by ion exchange with the regeneration solution. Regenerated based on.
[0004]
[Problems to be solved by the invention]
However, the conventional method has a problem that the operation of the apparatus must be temporarily interrupted when the ion exchanger is regenerated. In order to avoid this, there is an alternate operation method as a conventional method. In this system, while two apparatuses are installed and one apparatus is operating, the ion exchanger of the other apparatus is regenerated. However, this method causes another problem that the installation cost and the operation cost increase because two apparatuses are provided.
[0005]
Next, as a method of installing only one apparatus and performing the regeneration process of the ion exchanger without interrupting the operation, a method of performing the regeneration process in parallel during the operation can be considered. However, when this method is adopted, it is necessary to install a means for removing the regenerated liquid mist accompanying the gas accompanying the regeneration process and scattered downstream, for example, a mist separator (demister), etc., so that the apparatus becomes large. (In particular, the height is increased) and the installation cost is also high. Further, during the regeneration period, it is necessary to operate by reducing the gas flow rate to such an extent that the regeneration liquid mist can be captured.
Therefore, an object of the present invention is to provide an exhaust gas absorbing device that solves these problems and a gas treatment method using the same.
[0006]
[Means for Solving the Problems]
The invention according to claim 1 for solving the above-described problem is an exhaust gas absorption apparatus for removing a substance to be removed in a gas by ion exchange .
A body (1) through which the gas to be treated passes,
A plurality of frames closely connected to each other in the main body (1), and plate-like partition bodies (10) and (11) projectingly formed at the upper and lower ends of each of the frames, A plurality of ion exchange processing units (9) in which ion exchangers are arranged in the frame ;
The upper side of the partition member of the ion exchange treatment unit (9) respectively provided with gas passage opening and closing means in (11) (12),
A regeneration liquid recovery tank (5) provided at the bottom of the main body (1);
A plurality of branch pipes (15) connected to the recovery tank (5) via a pump (17) and provided corresponding to each of the plurality of ion exchange treatment units (9),
An on-off valve (14) provided in the middle of each of the branch pipes (15),
Regeneration liquid ejection nozzle (13) provided at the tip of each branch pipe (15), between the gas flow path opening / closing means (12) and the ion exchanger,
A gas supply section (3) for supplying a gas to be processed provided in the lower part of the main body;
An exhaust gas absorbing device comprising: a gas exhaust part (4) provided at an upper part of the main body and configured to exhaust gas .
[0007]
According to the exhaust gas absorbing device, the ion exchange processing unit arranged in the main body is divided into a plurality of parts independent of each other and arranged in parallel. Since each processing unit can sequentially perform regeneration processing at different times, the ion exchange processing units other than the regeneration processing can continue to operate as they are, and it is necessary to interrupt the operation of the apparatus during the regeneration processing. Absent. Furthermore, since the gas flow path opening / closing means of the ion exchange processing unit being regenerated can be closed, the regenerated liquid mist will not be scattered downstream. As a result, it is not necessary to reduce the gas flow rate during regeneration, and the gas can be processed at the maximum design flow rate that can be processed. Therefore, since the gas passage area can be designed to be small, the overall size of the apparatus can be made compact.
[0008]
Also, by increasing the number of ion exchange processing units arranged in close contact with each other in a divided form, the ion exchange processing unit and its gas passage area are reduced, so the capacity of the regeneration liquid recovery tank and transfer pump Can also be reduced.
Further, when the number of ion exchange processing units is n, the apparatus is designed with the processing capacity of n-1 ion exchange processing units, and the ion exchangers of any ion exchange processing units are in an operable state. It is also possible to operate n at the same time. In this case, the processing capacity of the entire apparatus is consequently temporarily increased.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory view for treating a gas using the exhaust gas absorbing device of the present invention.
In FIG. 1, the ion exchange part 2 is arrange | positioned in the center part of the main body 1 of the apparatus, the gas supply part 3 which supplies the gas which should be processed to the lower part, and the gas discharge which discharges the gas processed from the upper part to the exterior from the main body 1 Each part 4 is provided. Further, a recovery liquid recovery tank 5 is disposed at the bottom of the main body 1. An external supply pipe 6 is connected to the gas supply unit 3, and a gas transfer blower 7 is provided in the supply pipe 6. A discharge pipe 8 is connected to the gas discharge section 4, and the tip of the discharge pipe 8 is connected to, for example, a device that uses the processed gas, a secondary processing apparatus, or an atmospheric discharge section, although not shown.
[0012]
The ion exchange unit 2 includes a plurality of (in this example, four) ion exchange processing units 9 arranged in close contact independently, and each ion exchange processing unit 9 accommodates an ion exchanger. A plurality of plate-like partition bodies 10 are provided at the gas supply side (lower side) boundary portions of the respective ion exchange processing sections 9, and a plurality of plate-like partition bodies 11 are provided at the gas outlet side (upper side) boundary portions, respectively. Furthermore, gas flow path opening / closing means 12 such as a damper is individually provided on the gas outlet side of each ion exchange processing unit 9. The gas flow path opening / closing means 12 is remotely driven by pneumatic, hydraulic, electric or electromagnetic driving means.
On the gas outlet side of each ion exchange processing unit 9, nozzles 13 for ejecting the regenerating liquid are respectively arranged, and these nozzles 13 are connected to the front ends of a plurality of branch pipes 15 provided with on-off valves 14 in the middle. . These on-off valves 14 can also be remotely driven by a driving means such as pneumatic, hydraulic, electric or electromagnetic. Each branch pipe 15 is connected to the recovery tank 5 by a regenerating liquid pipe 18 provided with a pump 17. The nozzle 13, the on-off valve 14 and the branch pipe 15 constitute a regenerating liquid supply means 16.
[0013]
Each ion exchange processing unit 2 that accommodates the ion exchanger may be configured such that, for example, a plurality of frames are in close contact with each other and attached to the main body 1. And it is desirable to comprise so that the ion exchanger unit which accommodates an ion exchanger in each frame can be mounted | worn detachably.
As the ion exchanger, a fibrous ion exchange fiber or a granular ion exchange resin usually used in this field can be used. The ion exchange fiber is preferably formed by forming an ion exchange group on a fibrous body, has a large surface area per unit volume, and can increase the ion exchange rate.
[0014]
The types of ion exchangers include cation exchangers that exchange ions with cations and anion exchangers that exchange ions with anions. Depending on the ion form of the substance to be removed, the polarity of the ion exchanger is preferable. Exchange group selection is made. For example, when sulfurous acid gas is contained as a substance to be removed in the gas, an anion exchanger that exchanges SO ₃ ²⁻ ions of sulfurous acid gas with its own OH ⁻ ions is used.
As a regenerating liquid that desorbs ions of the substance to be removed adsorbed on the ion exchanger and regenerates the ion exchanger to the original ion form, a regenerating liquid having the same polarity as the adsorbed ions is used. For example, when SO ₃ ^2- ions as described above are adsorbed on the ion exchanger, a caustic soda (NaOH) solution or the like is used.
[0015]
Next, a method for performing gas treatment using the exhaust gas absorber will be described.
First, among the four ion exchange treatment units 9 of the exhaust gas absorption device, the ion exchanger in one ion exchange treatment unit 9 is in the regeneration process, and the other three ion exchange treatment units 9 perform gas treatment. Suppose that In this state, the gas flow path opening / closing means 12 of the three ion exchange processing units 9 that are performing gas processing are in an open state, and the gas introduced from the blower 7 into the gas supply unit 3 The substance to be removed while passing through the processing unit 9 is removed by ion exchange with the ion exchanger and is discharged to the gas discharge unit 4.
[0016]
On the other hand, in the ion exchange processing unit 9 performing the regeneration process of the ion exchanger, the gas flow path opening / closing means 12 is closed, so that the gas does not pass through the ion exchange processing unit 9. Similarly, since the on-off valve 14 for the ion exchange processing unit 9 is opened, the regeneration liquid is supplied from the recovery tank 5 arranged at the bottom of the main body 1 to the nozzle 13 by the pump 17 to perform the regeneration process. Yes. At that time, since the gas flow path opening / closing means 12 is closed as described above, the mist of the regenerated liquid supplied to the ion exchanger does not scatter to the downstream side and falls into the recovery tank 5 and is recovered. The
[0017]
When the regeneration process of one ion exchange processing unit 9 is completed in this way, the process is switched to the regeneration process of the next ion exchange processing unit 9 that requires the regeneration process. In order to perform this switching operation, first, the opening / closing valve 14 in the ion exchange processing unit 9 after the regeneration process is closed, and then the gas flow path opening / closing means 12 is opened when there is no possibility of the regeneration mist scattering from there. . By these operations, the ion exchange processing unit 9 that has been regenerated moves to the gas processing state (operating state).
Next, the gas flow path opening / closing means 12 of the ion exchange processing section 9 to be regenerated is closed, and the opening / closing valve 14 is opened. By these operations, the regeneration process of the ion exchanger of the new ion exchange processing unit 9 is started.
[0018]
By the same method, the regeneration process of the ion exchanger in still another ion exchange processing unit 9 is performed according to a predetermined schedule.
As described above, in order to sequentially perform the regeneration process by shifting the time for the plurality of ion exchange processing units 9, the gas channel opening / closing means 12 and the opening / closing valve 14 can be manually opened and closed and the pump 17 can be started and stopped manually. However, these operations can be automatically program-controlled using, for example, a sequencer or a computer.
[0019]
【The invention's effect】
As described above, the invention of the exhaust gas absorbing device described in claim 1 includes a main body through which a gas to be processed passes, a plurality of ion exchange treatment units arranged in close contact in parallel within the main body, and each ion exchange treatment. Gas passage opening / closing means provided in each part and a plurality of regenerative liquid supply means for individually supplying regenerative liquids to the ion exchangers accommodated in each ion exchange processing part. The ion exchange processing unit is divided into a plurality of parts independent of each other and arranged in parallel. Since each processing unit can sequentially perform regeneration processing at different times, the ion exchange processing units other than the regeneration processing can continue to operate as they are, and it is necessary to interrupt the operation of the apparatus during the regeneration processing. Absent.
[0020]
Furthermore, since the gas flow path opening / closing means of the ion exchange processing unit being regenerated can be closed, the regenerated liquid mist will not be scattered downstream. As a result, it is not necessary to reduce the gas flow rate during regeneration, and the gas can be processed at the maximum design flow rate that can be processed. Therefore, since the gas passage area can be designed to be small, the overall size of the apparatus can be made compact.
In addition, by increasing the number of ion exchange processing units arranged in close contact with each other in a divided form, the ion exchange processing unit and its gas passage area are reduced, so that the regeneration liquid recovery tank and transfer pump Capacity can also be reduced.
[0021]
Furthermore, a regenerative liquid recovery tank is provided at the bottom of the main body, a gas supply unit for supplying gas to be processed at the lower part, a plurality of ion exchange processing parts at the intermediate part, and a gas discharge part for discharging the processed gas at the upper part In addition, since the transfer means for transferring the regeneration liquid from the recovery tank to each regeneration liquid supply means is provided, the apparatus can be made more compact and the configuration of the regeneration processing part can be simplified.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an explanatory diagram for performing gas treatment using an exhaust gas absorption apparatus of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Main body 2 Ion exchange part 3 Gas supply part 4 Gas discharge part 5 Recovery tank 6 Supply pipe 7 Blower 8 Discharge pipe 9 Ion exchange processing part 10 Partition body 11 Partition body 12 Gas flow path opening / closing means 13 Nozzle 14 On-off valve 15 Branch pipe 16 Regenerating liquid supply means 17 Pump 18 Regenerating liquid piping

Claims (1)

In the exhaust gas absorption device that removes the substance to be removed in the gas by ion exchange,
A body (1) through which the gas to be treated passes,
A plurality of frames closely connected to each other in the main body (1), and plate-like partition bodies (10) and (11) projectingly formed at the upper and lower ends of each of the frames, A plurality of ion exchange processing units (9) in which ion exchangers are arranged in the frame ;
The upper side of the partition member of the ion exchange treatment unit (9) respectively provided with gas passage opening and closing means in (11) (12),
A regeneration liquid recovery tank (5) provided at the bottom of the main body (1);
A plurality of branch pipes (15) connected to the recovery tank (5) via a pump (17) and provided corresponding to each of the plurality of ion exchange treatment units (9),
An on-off valve (14) provided in the middle of each of the branch pipes (15),
Regeneration liquid ejection nozzle (13) provided at the tip of each branch pipe (15), between the gas flow path opening / closing means (12) and the ion exchanger,
A gas supply section (3) for supplying a gas to be processed provided in the lower part of the main body;
An exhaust gas absorbing device , comprising: a gas discharge unit (4) provided at an upper portion of the main body and configured to discharge gas .

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