JP5324106B2 - Alkaline wastewater neutralizer - Google Patents

Description

  TECHNICAL FIELD The present invention relates to an alkaline wastewater neutralization treatment apparatus that neutralizes by bringing combustion exhaust gas into contact with alkaline wastewater.

  As a neutralization treatment device for neutralizing alkaline wastewater, a device equipped with a neutralization treatment tank for neutralizing wastewater using combustion exhaust gas discharged from a boiler or a gas engine has been proposed (for example, Patent Document 1). The neutralization treatment tank in this neutralization treatment apparatus includes a gas-liquid contact chamber into which alkaline drainage to be neutralized flows and an exhaust gas chamber into which combustion exhaust gas from a boiler or a gas engine flows, and an exhaust gas chamber And the gas-liquid contact chamber are partitioned by a ventilation partition wall body, and a plurality of ventilation slits are provided in the ventilation partition wall body at intervals in a predetermined direction. In such a neutralization treatment tank, the combustion exhaust gas supplied to the exhaust gas chamber is supplied to the gas-liquid contact chamber through the plurality of slits of the ventilation partition wall body, and the supplied combustion exhaust gas is gasified. Gas-liquid contact is made with the alkaline drainage in the liquid contact chamber, and the alkaline drainage is neutralized by this gas-liquid contact.

JP 2005-144419 A

  In the conventional neutralization tank, the ventilation partition wall body is composed of an elongated plate-shaped partition member, and a ventilation slit is defined between adjacent partition members. Moreover, since combustion exhaust gas flows through a ventilation slit, the partition member is formed, for example from stainless steel.

However, in such a neutralization treatment tank, when alkaline wastewater is neutralized under specific conditions, the following chemical reaction,
2NaOH + CO ₂ → Na ₂ CO ₃ + H ₂ O (1)
To form sodium carbonate as a neutralized product. When the neutralized product reaches a certain concentration, it is difficult to dissolve, and there is a problem that it adheres to the surface of the ventilation partition wall as a scale.

  If the scale adheres to the ventilation partition wall, a part or most of the ventilation slit may be blocked. If the scale is blocked, the flow of combustion exhaust gas through the ventilation slit is deteriorated, and the combustion exhaust gas is reduced. The efficiency of the neutralization process used decreases. In addition, if the scale adheres to the ventilation partition wall for a long period of time, it is necessary to stop the neutralization treatment at regular intervals and clean the ventilation partition wall to remove the adhered scale. As a result, there is a problem in that the movable efficiency of the neutralization tank is lowered.

  An object of the present invention is to provide an alkaline wastewater neutralization treatment apparatus capable of supplying combustion exhaust gas through a ventilation slit over a long period of time while suppressing adhesion of scale to a ventilation partition wall body of a neutralization treatment tank. .

An alkaline wastewater neutralization treatment apparatus according to claim 1 of the present invention includes a neutralization treatment tank for neutralizing alkaline wastewater, and an exhaust gas feed for supplying combustion exhaust gas to the neutralization treatment tank. An alkaline wastewater neutralization treatment apparatus that neutralizes the exhaust gas from the exhaust gas feeding means in contact with the alkaline wastewater in the neutralization treatment tank,
The neutralization treatment tank includes an exhaust gas chamber into which combustion exhaust gas from the exhaust gas feeding means flows, and a gas-liquid contact chamber into which alkaline drainage flows, and the exhaust gas chamber, the gas-liquid contact chamber, There is a ventilation partition wall in between ,
The ventilation partition wall body is composed of a plurality of partition members disposed at intervals in a predetermined direction, and each of the plurality of partition members is a heat-resistant and chemical-resistant resin in which inclined surfaces are formed on both side surfaces. And a pair of reinforcing members disposed on both sides of the partition body,
Both side portions of the partition body protrude from the pair of reinforcing members on both sides, and ventilation slits extending in an oblique direction are defined between partition bodies of partition members adjacent in the predetermined direction .

In the alkaline wastewater neutralization treatment apparatus according to claim 2 of the present invention, the heat-resistant chemical-resistant resin is a fluororesin or a phenol resin.
Furthermore, in the alkaline wastewater neutralization treatment apparatus according to claim 3 of the present invention, the gas-liquid contact chamber of the neutralization treatment tank includes a lower gas-liquid contact chamber disposed above the exhaust gas chamber, The upper gas-liquid contact chamber is disposed above the lower gas-liquid contact chamber, and a first ventilation partition wall is provided between the exhaust gas chamber and the lower gas-liquid contact chamber, A second ventilation partition wall body is provided between the contact chamber and the upper gas-liquid contact chamber, and each of the first ventilation partition wall body and the second ventilation partition wall body is arranged with an interval in a predetermined direction. Each of the plurality of partition members is disposed on both sides of the partition body, and a partition body made of a heat-resistant and chemical-resistant resin having inclined surfaces formed on both side surfaces. A pair of reinforcing members, and both side portions of the partition main body protrude from the pair of reinforcing members on both sides, in the predetermined direction. Wherein the vent slit extending obliquely between the partition body contact the partition member is defined.

According to the alkaline wastewater neutralization treatment apparatus of the first aspect of the present invention, the ventilation partition wall body is provided between the exhaust gas chamber and the gas-liquid contact chamber of the neutralization tank, and the ventilation partition wall body includes A plurality of ventilation slits extending in an oblique direction are provided, and the plurality of ventilation slits are defined by a heat-resistant chemical-resistant resin, so that neutralized products (so-called scales) generated by gas-liquid contact with combustion exhaust gas ) And heat-resistant chemical-resistant resin is low, which prevents the neutralized product from sticking to the heat-resistant chemical-resistant resin and prevents the neutralized product from blocking the ventilation slit Even if it is attached, it can be easily removed. The ventilation partition wall body includes a plurality of partition members, each of the partition members having a partition body made of a heat-resistant and chemical-resistant resin and a pair of reinforcing members disposed on both surfaces of the partition body. Since both side portions of the main body protrude on both sides from the pair of reinforcing members, the ventilation slit is defined by the heat-resistant chemical-resistant resin and suppresses the adhesion of the neutralized product to the ventilation slit. be able to. In addition, since the reinforcing members are disposed on both sides of the partition member, the strength of the ventilation partition wall body can be increased.

Moreover, according to the alkaline wastewater neutralization treatment apparatus according to claim 2 of the present invention, a fluororesin or a phenol resin can be used as the heat-resistant chemical-resistant resin, and the thermal expansion is not large, so that it is advantageously used. Can do.

Furthermore, according to the alkaline wastewater neutralization treatment apparatus according to claim 3 of the present invention, the gas-liquid contact chamber of the neutralization treatment tank includes a lower gas-liquid contact chamber disposed above the exhaust gas chamber, and a lower gas-liquid contact chamber. The upper gas-liquid contact chamber disposed above the gas-liquid contact chamber is configured to contact the lower gas-liquid contact with the first ventilation partition wall disposed between the exhaust gas chamber and the lower gas-liquid contact chamber. The ventilation partition wall body having the above-described configuration can be applied to the second ventilation partition wall body disposed between the chamber and the upper gas-liquid contact chamber.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS An embodiment of an alkaline wastewater neutralizing apparatus according to the invention will be described below with reference to the accompanying drawings. FIG. 1 is a simplified view schematically showing the entire alkaline wastewater neutralization treatment apparatus of one embodiment, and FIG. 2 is a cross-sectional view showing a neutralization treatment tank in the neutralization treatment apparatus of FIG. 3 is an enlarged sectional view showing a part of the ventilation partition wall body in the neutralization treatment tank of FIG. 2, and FIG. 4 is an enlarged sectional view showing a part of the modified ventilation partition wall body. is there.

  1 and 2, the illustrated alkaline wastewater neutralization apparatus includes a neutralization treatment tank 2 that neutralizes the exhaust gas by contacting the combustion exhaust gas with alkaline wastewater. In this embodiment, the neutralization tank 2 includes a lower housing 4 and an upper housing 6, an exhaust gas chamber 8 is defined in the lower housing 4, and a lower gas / liquid contact chamber 10 and an upper gas / liquid contact are formed in the upper housing 6. A chamber 12 is defined.

  Combustion exhaust gas is supplied to the exhaust gas chamber 8. In this embodiment, the combustion exhaust gas from the gas engine 14 of the cogeneration system is used, and a part of the combustion exhaust gas from the gas engine 14 is neutralized through the exhaust gas supply means 20. 2 to the exhaust gas chamber 8. The exhaust gas supply means 20 includes an exhaust gas supply pipe 22 for introducing combustion exhaust gas to the exhaust gas chamber 8 and a supply blower 24 disposed in the exhaust gas supply pipe 22. A part of the combustion exhaust gas is supplied to the neutralization treatment tank 2 through the exhaust gas supply pipe 22 by the supply blower 24. Instead of the gas engine 14, combustion exhaust gas from a boiler or the like may be used.

  In this neutralization treatment tank 2, a lower gas / liquid contact chamber 10 is disposed above the exhaust gas chamber 8, and an upper gas / liquid contact chamber 12 is disposed above the lower gas / liquid contact chamber 10. 8 and the lower gas-liquid contact chamber 10 are provided with a lower ventilation partition wall body 26 (which constitutes a first ventilation partition wall body), and between the lower gas-liquid contact chamber 10 and the upper gas-liquid contact chamber 12. An upper ventilation partition wall 28 (which constitutes a second ventilation partition wall) is provided. In this embodiment, a supply port 30 for supplying alkaline drainage to be neutralized is provided at one end of the upper gas-liquid contact chamber 12 (the right end in FIGS. 1 and 2), and one end of the lower gas-liquid contact chamber 10 is provided. 1 (the right end in FIGS. 1 and 2) is provided with a discharge port 32 for discharging the neutralized alkaline drainage, and the other ends of the upper gas-liquid contact chamber 12 and the lower gas-liquid contact chamber 10 (FIG. 1). In addition, a communication pipe 34 for supplying the alkaline waste water in the upper gas-liquid contact chamber 12 to the lower gas-liquid contact chamber 10 is provided on the left end side in FIG.

  The lower ventilation partition wall body 26 and the upper ventilation partition wall body 28 have substantially the same configuration. Each of the ventilation partition wall bodies 26 and 28 has a plurality of ventilation slits 36 and 38 spaced in a predetermined direction. Is provided. Referring also to FIG. 3, the lower ventilation partition wall body 26 (upper ventilation partition wall body 28) has a plurality of partition members 40 disposed at intervals in a predetermined direction (the left-right direction in FIGS. 2 and 3). A ventilation slit 36 (38) is defined between adjacent partition members 40. Each ventilation slit 36 (38) is provided so as to extend obliquely in an oblique direction, and the combustion exhaust gas passes through the ventilation slit 36 (38) and the alkaline waste water in the lower gas-liquid contact chamber 10 (upper gas-liquid contact chamber 12). The gas-liquid contact between the combustion exhaust gas and the alkaline drainage is performed.

  Each partition member 40 of the lower ventilation partition wall body 26 (upper ventilation partition wall body 28) includes an elongated plate-like partition body 42, and the partition body 42 is made of, for example, stainless steel. Both side surfaces (left and right side surfaces in FIG. 3) of the partition main body 42 are inclined and extend, and a ventilation slit 36 (38) is defined between the inclined surfaces facing each other of the adjacent partition members 40.

  In this embodiment, the entire surface of the partition main body 42 is covered with the heat resistant chemical resistant resin layer 44, and the ventilation slit 36 (38) is defined between the heat resistant chemical resistant resin layers 44 of the adjacent partition members 40. ing. As the heat-resistant and chemical-resistant resin, a fluororesin is preferable. As this fluororesin, for example, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA) or polytetrafluoroethylene (PTFE) can be used. When such a resin is used, it can be applied to the surface substantially uniformly by powder coating such as spray coating or baking coating. The thickness t of the heat-resistant resin layer 44 is preferably 30 to 100 μm. If the thickness t is less than 30 μm, the alkaline drainage may reach the partition main body 42 to cause surface peeling, and if it exceeds 100 μm, the partition main body 42 is exceeded. The stability of the resin layer 44 is reduced, and it is not possible to withstand the strong impact caused by the collision of the drainage when exposed to high-temperature combustion exhaust gas. is there.

  The thickness T of the partition member 40 of the lower ventilation partition wall body 26 (upper ventilation partition wall body 28) is set to, for example, about 4 to 7 mm, for example, 5 mm, and the slit width S of the ventilation slit 36 (38) is It is set to about 2-8 mm, and by setting it as such a range, alkaline wastewater can be neutralized efficiently.

  Alkaline drainage from the drainage tank 46 is supplied to the supply port 30 of the upper gas-liquid contact chamber 12 of the neutralization treatment tank 2. The drainage tank 46 and the upper gas-liquid contact chamber 12 of the neutralization treatment tank 2 are connected via a drainage supply pipe 48, and a drainage supply pump 50 is disposed in the drainage supply pipe 48. Alkaline drainage generated in a factory or the like is temporarily stored in the drainage tank 46, and the alkaline drainage in the drainage tank 46 is supplied to the upper gas-liquid contact chamber 12 through the drainage supply pipe 48 by the action of the drainage supply pump 50. .

  Next, the neutralization process of the alkaline waste water by the neutralization apparatus mentioned above is demonstrated. When the neutralization treatment is performed, the alkaline drainage accumulated in the drainage tank 46 is supplied to the upper gas-liquid contact chamber 12 through the drainage supply pipe 48. The alkaline drainage supplied in this way flows from one end side (right end side in FIG. 2) to the other end side (left end side in FIG. 2) of the upper gas-liquid contact chamber 12, and then passes through the communication pipe 34 to lower air liquid. It is fed to the contact chamber 10. The alkaline drainage supplied to the lower gas-liquid contact chamber 10 in this way flows from the other end side (left end side in FIG. 2) of the lower gas-liquid contact chamber 10 to one end side (right end side in FIG. 2). It is discharged to the outside from the discharge port 32 provided in.

  A part of the combustion exhaust gas from the gas engine 14 is fed to the exhaust gas chamber 8 of the neutralization tank 2 through the exhaust gas feed pipe 22 by the action of the feed blower 24. Then, the supplied combustion exhaust gas is supplied to the lower gas-liquid contact chamber 10 through a number of ventilation slits 36 provided in the lower ventilation partition wall body 26, and then a large number of gas provided in the upper ventilation partition wall body 28. After being fed to the upper gas-liquid contact chamber 12 through the ventilation slit 38, it is discharged to the outside through a gas discharge port 54 provided in the upper wall 52.

  In the upper gas-liquid contact chamber 12, the alkaline drainage supplied from the drainage tank 46 and the combustion exhaust gas fed through the ventilation slit 38 of the upper ventilation partition wall 28 are in gas-liquid contact and contained in the combustion exhaust gas. The neutralized treatment of the alkaline waste water is performed using the carbon dioxide. At this time, since the surface of the partition member 40 of the upper ventilation partition wall 28 is covered with the heat-resistant chemical-resistant resin layer 44, the partition member for the neutralized product (so-called scale) generated by the neutralization treatment Adhesion to 40 is suppressed, thereby preventing the ventilation slit 38 from being blocked by the neutralized product. Accordingly, the combustion exhaust gas can be stably supplied to the upper gas-liquid contact chamber 12 through the ventilation slit 38 of the upper ventilation partition wall 28, and the processing efficiency of the neutralization process in the upper gas-liquid contact chamber 12 is reduced. Can be suppressed.

  The alkaline waste water neutralized in the upper gas / liquid contact chamber 12 in this way is fed to the lower gas / liquid contact chamber 10 through the communication pipe 34. In the lower gas-liquid contact chamber 10, almost the same as the upper gas-liquid contact chamber 12, the alkaline drainage and the combustion exhaust gas fed through the ventilation slit 36 of the lower ventilation partition wall body 26 are in gas-liquid contact. Also in the gas-liquid contact chamber 10, the alkaline waste water is neutralized using carbon dioxide in the combustion exhaust gas. At this time, since the surface of the partition member 40 of the lower ventilation partition wall body 26 is covered with the heat-resistant chemical resistant resin layer 44, the lower ventilation partition wall body 26 also partitions the neutralized product (so-called scale). Adhesion to the member 40 is suppressed, whereby the ventilation slit 36 is prevented from being blocked by the neutralized product, and the combustion exhaust gas can be stably supplied through the ventilation slit 36 of the upper ventilation partition wall body 26.

  The lower ventilation partition wall and / or the upper ventilation partition wall can be configured as shown in FIG. In FIG. 4, each partition member 40A of the lower ventilation partition wall body 26A (upper ventilation partition wall body 28A) includes an elongated plate-like partition body 42A, and the partition body 42A is formed of a heat-resistant chemical-resistant resin. Both side surfaces (left and right side surfaces in FIG. 4) of the partition main body 42A are inclined and extend, and a ventilation slit 36A (38A) is defined between the opposing inclined surfaces of the adjacent partition main body 42A. As the heat-resistant and chemical-resistant resin, fluororesin or phenol resin is desirable, and even when exposed to high-temperature combustion exhaust gas, the interval between the ventilation slits hardly changes and the combustion exhaust gas can flow stably. As the fluororesin, for example, polytetrafluoroethylene (PTFE) or polyvinylidene fluoride (PVDF) can be used.

  In this embodiment, reinforcing members 62 and 64 are provided on both surfaces of the partition main body 42A. The reinforcing members 62 and 64 are made of, for example, stainless steel. By providing the reinforcing members 62 and 64 in this way, the strength of the partition member 42A can be increased. Both inclined side portions of the partition main body 42A protrude from both side portions of the pair of reinforcing members 62 and 64, and a ventilation slit 36A (38A) is defined between the protruding side portions of the adjacent partition main body 42A.

  In this partition member 40A, the thickness t1 of the partition body 42A is set to about 4 to 7 mm, for example, 5 mm, the slit width S1 of the ventilation slit 36A (38A) is set to about 2 to 8 mm, and The thickness t2 of the reinforcing members 62 and 64 is set to about 2 to 3 mm. In order to prevent the flow of combustion exhaust gas from flowing through the ventilation slit 36A (38A), both side portions of the reinforcing members 62 and 64 are extended from an extended line of the inclined surface of the partition body 42A that defines the ventilation slits 36A and 38A. Further, it is preferable that the exhaust gas exhaust gas flowing through the ventilation slit 36 </ b> A (38 </ b> A) collide with the reinforcing members 62 and 64.

  Even when the lower ventilation partition wall body 26A (and / or the upper ventilation partition wall body 28A) having such a configuration is used, the partition main body 42A made of heat-resistant and chemical-resistant resin defines the ventilation slit 36A (38A). Therefore, in the same manner as described above, the neutralization product (so-called scale) is prevented from adhering to the partition body 42A, thereby preventing the ventilation slit 36A (38A) from being blocked by the neutralization product, and the lower ventilation The combustion exhaust gas can be stably supplied through the ventilation slit 36A (38A) of the partition wall body 26A (upper ventilation partition wall body 28A).

  As mentioned above, although one Embodiment of the alkaline waste water neutralization processing apparatus according to this invention was described, this invention is not limited to this Embodiment, Various deformation | transformation thru | or correction | amendment are possible, without deviating from the scope of the present invention. It is.

  For example, in the above-described embodiment, the gas-liquid contact chambers 10 and 12 have been described as being applied in a two-stage arrangement in the vertical direction. The present invention can be similarly applied to a stepped type or a case where gas-liquid contact chambers are arranged in three or more levels in the vertical direction.

BRIEF DESCRIPTION OF THE DRAWINGS The simplified figure which shows simply the whole alkaline wastewater neutralization processing apparatus of one Embodiment. Sectional drawing which shows the neutralization processing tank in the neutralization processing apparatus of FIG. Sectional drawing which expands and shows a part of ventilation partition wall body in the neutralization processing tank of FIG. Sectional drawing which expands and shows a part of ventilation partition wall body of a deformation | transformation form.

Explanation of symbols

2 Neutralization treatment tank 8 Exhaust gas chamber 10, 12 Gas-liquid contact chamber 14 Gas engine 20 Exhaust gas supply means 22 Exhaust gas supply pipe 26, 26A, 28, 28A Ventilation partition wall 30 Supply port 32 Discharge port 34 Communication Pipe 36, 38, 36A, 38A Ventilation slit 40, 40A Partition member 42, 42A Partition body 44 Heat resistant resin layer 62, 64 Reinforcing member

Claims (3)

A neutralization treatment tank for neutralizing the alkaline waste water; and an exhaust gas supply means for supplying combustion exhaust gas to the neutralization treatment tank. An alkaline wastewater neutralizing apparatus for neutralizing a combustion exhaust gas from a supply means by bringing the exhaust gas into contact with alkaline wastewater,
The neutralization treatment tank includes an exhaust gas chamber into which combustion exhaust gas from the exhaust gas feeding means flows, and a gas-liquid contact chamber into which alkaline drainage flows, and the exhaust gas chamber, the gas-liquid contact chamber, There is a ventilation partition wall in between ,
The ventilation partition wall body is composed of a plurality of partition members disposed at intervals in a predetermined direction, and each of the plurality of partition members is a heat-resistant and chemical-resistant resin in which inclined surfaces are formed on both side surfaces. And a pair of reinforcing members disposed on both sides of the partition body,
Alkaline drainage neutralization characterized in that both side portions of the partition body protrude from the pair of reinforcing members on both sides, and vent slits are defined extending obliquely between partition bodies of partition members adjacent in the predetermined direction. Processing equipment. The alkaline wastewater neutralization treatment apparatus according to claim 1 , wherein the heat-resistant chemical-resistant resin is a fluororesin or a phenol resin. The gas-liquid contact chamber of the neutralization treatment tank is composed of a lower gas-liquid contact chamber disposed above the exhaust gas chamber and an upper gas-liquid contact chamber disposed above the lower gas-liquid contact chamber. A first vent partition wall is provided between the exhaust gas chamber and the lower gas-liquid contact chamber, and a second vent partition wall is provided between the lower gas-liquid contact chamber and the upper gas-liquid contact chamber. Each of the first ventilation partition wall body and the second ventilation partition wall body is composed of a plurality of partition members arranged at intervals in a predetermined direction, and each of the plurality of partition members is A partition body made of heat-resistant and chemical-resistant resin having inclined surfaces formed on both side surfaces, and a pair of reinforcing members disposed on both surfaces of the partition body, wherein both sides of the partition body are the pair A ventilation slit that protrudes from the reinforcing member on both sides and extends obliquely between the partition bodies of the partition members adjacent to each other in the predetermined direction is regulated. Alkaline wastewater neutralization treatment apparatus according to claim 1, characterized in that it is.

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