JPH11262778A - Apparatus for neutralizing boiler waste water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To regulate the concn. of CO2 in the exhaust gas supplied to a neutralizing apparatus on the basis of the oxygen consumption of boiler waste water by providing with an exhaust gas supply pipe with an air introducing means. SOLUTION: An air introducing means 11, for example, an air introducing valve is disposed in an exhaust gas supply pipe 7 along with a drain separator 9 and an exhaust gas pump 10. The pH value and temp. of the boiler discharge water overflowing from a treatment tank 2 are measured by a pH detector 22 and a temp. detector 21. When the measured pH value and temp. are not fitted to discharge water standards (water low in oxygen consumption), the air introducing means 11 is operated to regulate the pH value. That is, the concn. of CO2 in the exhaust gas is diluted to set a pH equilibrium value to a prescribed range. The temp. of waste water is controlled to prescribed temp. of lower by the heat exchanger 23 of the treatment tank 2. By this constitution, this apparatus can correspond to a large capacity boiler and neutralization treatment can be certainly performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a neutralization device for mixing and neutralizing boiler wastewater with boiler wastewater.

[0002]

2. Description of the Related Art Since boiler can water is alkaline,
In the case of drainage, it is necessary to carry out a neutralization treatment in order to meet the drainage standards. For example, various neutralization devices have been proposed in which boiler wastewater is stored in a treatment tank, and exhaust gas from the boiler is supplied and mixed into the treatment tank to neutralize the boiler wastewater.

[0003] However, in the neutralization device, since boiler exhaust gas contains about 10% of acidic components such as carbon dioxide, when the acid consumption of the boiler wastewater is low, mixing with the exhaust gas is required. May increase the acidic content and may not meet drainage standards.

[0004]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention provides a boiler drainage system capable of adjusting the concentration of CO _{2 in} exhaust gas supplied to a neutralization unit based on the acid consumption of the boiler wastewater. It is intended to provide a neutralization device.

[0005]

Means for Solving the Problems The present invention has been made to solve the above problems, and the invention according to claim 1 is provided with a processing tank for introducing boiler drainage,
An exhaust gas supply pipe, a concentration blow pipe and a can bottom blow pipe are connected to the treatment tank, and an overflow pipe and a discharge pipe are connected to the treatment tank. The invention according to claim 2 is characterized in that a plurality of treatment tanks for introducing boiler drainage are connected in communication,
An exhaust gas supply pipe is connected to each of the processing tanks, a concentration blow pipe and a can bottom blow pipe are connected to the processing tank located at the most upstream side, and an overflow pipe and a discharge pipe are connected to the processing tank located at the most downstream side. In the boiler wastewater neutralization device having a connected configuration, an air introduction means is provided in the exhaust gas supply pipe, and the invention according to claim 3 further comprises a boiler can bottom and the treatment tank. An auxiliary tank is provided in the middle of the bottom blow pipe to be connected.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described. The boiler waste water neutralizing apparatus of the present invention is provided with a treatment tank for introducing boiler waste water, and the boiler exhaust gas is supplied to the treatment tank. Exhaust gas supply pipe, a concentration blow pipe and a can bottom blow pipe, an overflow pipe and a discharge pipe for discharging treated water from the treatment tank, and an air introducing means (for example, air) to the exhaust gas supply pipe. (Introduction valve).

[0007] According to the boiler wastewater neutralizing apparatus having the above-described structure, the concentrated blow water and the can bottom blow water of the boiler are introduced into the treatment tank via the concentrated blow pipe and the can bottom blow pipe. The concentrated blow water of the boiler is
Introduced into the processing tank during the combustion operation of the boiler,
Exhaust gas generated by combustion is mixed and neutralized.
The increased water in the treated water tank is discharged from the overflow pipe, and the boiler wastewater is continuously neutralized. In addition, the bottom blow water of the boiler is introduced into the processing tank while the operation of the boiler is stopped. Prior to the introduction of the can bottom blow water, the water in the treatment tank is discharged from the discharge pipe to a predetermined water level, and after the discharge, the can bottom blow water is introduced into the treatment tank. Then, the operation of the boiler is started, and exhaust gas generated by combustion is mixed and neutralized. When the operation of the boiler is started, the process automatically shifts to the step of treating the concentrated blow water.

Incidentally, depending on the quality of raw water (eg, well water, industrial water, etc.) supplied to the boiler (eg, water with a low acid consumption), boiler drainage (concentrated blow water, can bottom) introduced into the treatment tank is required. The blow water) also has a lower pH than the normal one. Therefore, when the exhaust gas having a CO ₂ concentration of about 10% and the boiler wastewater are mixed in the treatment tank, the boiler wastewater that does not conform to the wastewater standard is discharged. Therefore, according to the boiler wastewater neutralization apparatus of the present invention, the water quality of raw water or boiler wastewater supplied to the boiler is analyzed, and the CO ₂ concentration of the exhaust gas supplied to the treatment tank is adjusted based on the measured value. . That is, an air introduction valve provided as an air introduction means provided in an exhaust gas supply pipe for supplying exhaust gas to the processing tank is opened, and the air introduction valve is opened so that the boiler wastewater has a pH value that meets wastewater standards. Adjust the degree.

As described above, according to the present invention, even when raw water having a locally different water quality is supplied to the boiler, the CO ₂ concentration in the exhaust gas for neutralizing the boiler waste water is adjusted and supplied. Boiler wastewater that meets drainage standards.

Next, an embodiment which is an alternative to the above embodiment will be described. The boiler wastewater neutralizing device described in this embodiment differs from the boiler wastewater neutralizing device in the configuration of the processing tank described in the above embodiment. That is, a plurality of processing tanks for introducing the drainage of the boiler are connected to each other, and an exhaust gas supply pipe for supplying the exhaust gas of the boiler to each processing tank is connected. Then, the concentration blow pipe and the can bottom blow pipe are connected to the processing tank located at the most upstream side, and the overflow pipe and the discharge pipe are connected to the processing tank located at the most downstream side. The configuration other than the above is the same as that of the above-described embodiment, and the description is omitted.

According to the boiler waste water neutralizing apparatus having the above-described structure, the concentrated blow water flows into the processing tank located at the most downstream side via the processing tank located at the most upstream side during the combustion operation of the boiler. Inflow. In this distribution process, the exhaust gas supplied from the exhaust gas supply pipe is mixed and neutralized. Then, the increased water in the processing tank located on the most downstream side is discharged from the overflow pipe. Also,
The bottom blow water is introduced into the processing tank located on the uppermost stream side while the operation of the boiler is stopped. Prior to the introduction of the can bottom blow water, the water in the processing tank located on the most downstream side is discharged from the discharge pipe to a predetermined water level, and after discharging, the can bottom blow is introduced into the processing tank located on the most upstream side. Introduce water. The bottom blow water is mixed with the concentrated blow water neutralized in the processing tank located on the most upstream side, and the increased water flows into the processing tank located on the most downstream side.
Then, the operation of the boiler is started, and exhaust gas generated by combustion is mixed and neutralized. When the operation of the boiler is started, the process automatically shifts to a step of treating the concentrated blow water. If the quality of the raw water supplied to the boiler is water with a low acid consumption, the operation is the same as the operation of the air introducing means described in the above embodiment, and the description is omitted.

Further, an auxiliary tank may be provided in the middle of the can bottom blow pipe connecting the bottom of the boiler and the processing tank (upstream stream side). Since the auxiliary tank precipitates and separates impurities such as sludge contained in the can bottom blow water, maintenance (cleaning, etc.) of the processing tank can be eliminated.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory view schematically showing a configuration of a first embodiment of a boiler wastewater neutralization apparatus attached to a boiler embodying the present invention.

In FIG. 1, a neutralization device 1 has a treatment tank 2 for neutralizing boiler wastewater near a boiler 3. A partition plate 4 is provided at the center of the processing tank 2, and the upper and lower portions are divided into an inflow side and an outflow side in a state of communication.

In the exhaust gas passage 5 of the boiler 3, a economizer 6
And one end of an exhaust gas supply pipe 7 is connected to a position downstream of the economizer 6. The other end of the exhaust gas supply pipe 7 is connected to the processing tank 2 for introducing boiler drainage, and the exhaust gas of the boiler 3 is mixed with the boiler drainage in the processing tank 2 from the nozzle 8 at the tip. ing. A drain separator 9, an exhaust gas pump 10
And an air introduction means 11 (for example, an air introduction valve).

The boiler 3 includes a separator 12,
A concentration blow pipe 14 is connected to a part of the downcomer 13 below the separator 12. The tip of the concentration blow pipe 14 is connected to the inflow side of the processing tank 2. Also,
The concentration blow pipe 14 is provided with a concentration blow solenoid valve 15. On the other hand, a can bottom blow pipe 16 is connected to the bottom of the boiler 3. The distal end of the can bottom blow pipe 16 is connected to the processing tank 2, and is configured to join the concentration blow pipe 14. The can bottom blow pipe 16 is provided with a can bottom blow solenoid valve 17.

An overflow pipe 18 is provided at the upper part on the outflow side of the processing tank 2, and a discharge pipe 20 provided with a discharge solenoid valve 19 is provided at the lower part, and a distal end of the discharge pipe 20 is connected to the overflow pipe 18. I have. A temperature detector 21 and a pH detector 22 for detecting the temperature and pH of the boiler wastewater are provided above the processing tank 2. Further, a heat exchanger 23 for cooling boiler wastewater is provided in the processing tank 2. This heat exchanger 2
Reference numeral 3 is connected to a water supply pipe 24 for supplying water to the boiler 3. The water supply pipe 24 is connected to the economizer 6 via the raw water supply source 25 and the heat exchanger 24, and further via the heat exchanger (not shown) in the economizer 6. It is connected to the boiler 3 can. Further, the processing tank 2 is provided with a water level detector (not shown) provided with a high water level detecting unit and a low water level detecting unit for detecting a water level in the processing tank 2.

An operation control unit (not shown) of the boiler 3,
The exhaust gas pump 10, the air introduction means 11, the concentration blow solenoid valve 15, the can bottom blow solenoid valve 17,
The discharge solenoid valve 19, the temperature detector 21, and the pH detector 22 are connected to a controller 27 via a signal line 26, respectively. The water level detector (not shown) is also connected to the controller 27 via a signal line (not shown).

The normal operation of the above configuration will be described. Boiler wastewater is roughly divided into concentrated blow water that discharges concentrated can water during boiler combustion operation and can bottom blow water that is discharged from the bottom of the can body when the boiler is stopped. The sum processing will be described. The concentrated blow water is supplied to the processing tank 2 by receiving a signal from the controller 27 of the boiler 3 and opening the concentrated blow solenoid valve 15.
Flows into the interior. Then, upon receiving a high water level detection signal from a water level detector (not shown) for detecting the water level in the processing tank 2, the exhaust gas pump 10 operates. This exhaust gas pump 1
0 is operated in synchronization with the combustion of the boiler 3. Then, the boiler wastewater cooled by the heat exchanger 23 after mixing and neutralizing the exhaust gas from the boiler 3 is discharged from the overflow pipe 18 with an increased water content. Next, the neutralization treatment of the can bottom blow water will be described. A combustion switch (not shown) of the boiler 3 is turned off by a signal from the controller 27. Next, the electromagnetic valve 15 for discharging is opened at the same time when the electromagnetic valve 15 for concentration blow is closed, and the water in the processing tank 2 is discharged. Then, upon receiving the low water level detection signal from the water level detector, the discharge solenoid valve 9 is closed. Next, the can bottom blow solenoid valve 17 is opened,
The can bottom blow water is introduced into the treatment tank 2, and after the entire blow, the solenoid valve 17 for can bottom blow is closed. And
When the operation of the boiler 3 is started, the exhaust gas pump 10 operates to mix the exhaust gas with the bottom blow water. Subsequent operations are the same as those of the concentrated blow water.

Next, the operation of the boiler waste water neutralizing device of the present invention will be described. First, as shown in FIG. 2 and FIG. 3, the drainage standard of industrial wastewater ranges from pH 5.8 (acidic) to pH 8.6 (alkaline) across neutral (pH 7).
(This regulation value is a regulation value that varies depending on the water area, and the lower limit is pH 5.0 and the upper limit is pH 9.0.) Further, the drainage temperature is 45 ° C. or less. Therefore, the boiler wastewater that overflows from the treatment tank 2 and is drained is p
The H value and the temperature are measured by a pH detector 22 and a temperature detector 21.
It is measured in. And when the measured value does not meet the drainage standard (water with low acid consumption (see FIG. 2)),
By operating the air introduction means 11 provided in the exhaust gas supply pipe 7, p
Adjust so that the H value matches. This air introduction means 11
The CO ₂ concentration in the exhaust gas (about 10
%) Is diluted with air, and the CO ₂ concentration is reduced, so that the pH equilibrium value can be within a specified range as shown in FIG. The temperature of the waste water is lower than the regulated temperature by the heat exchanger 21 provided in the processing tank 2.

Next, a second embodiment, which is another embodiment, of the boiler wastewater neutralizing device of the present invention will be described with reference to the drawings. FIG. 4 is an explanatory view schematically showing the configuration of a second embodiment of the neutralization device according to the present invention. Note that the same members as those in the first embodiment are denoted by the same reference numerals, and redundant description will be omitted.

The neutralizing device 1 described in the second embodiment is
The configuration of the processing tank 2 described in the first embodiment is different. That is, as shown in FIG.
Treatment tank 2A provided with partition plate 4 for introducing wastewater
And the second processing tank 2B provided with the partition plate 4 are connected via a connecting pipe 28, and the exhaust gas supply pipe 7 for supplying the exhaust gas of the boiler 3 to the first and second processing tanks 2A and 2B is connected. ing. The first processing tank 2A is connected to a concentration blow pipe 14 and a can bottom blow pipe 16, and the second processing tank 2B is connected to an overflow pipe 18 and a discharge pipe 20. The configuration other than the above is the same as that of the first embodiment, and the description is omitted.

According to the boiler waste water neutralizing apparatus 1 having the above-described structure, the concentrated blow water flows into the first processing tank 2A during the combustion operation of the boiler 3, and the second processing tank 2A is connected through the connecting pipe 28. Flow into 2B. In the flow of the concentrated blow water, the exhaust gas of the boiler 3 is supplied from the exhaust gas supply pipe 7 into the first and second processing tanks 2A and 2B,
It is mixed with the concentrated blow water and neutralized. The increased water in the second processing tank 2B is discharged from the overflow pipe 18. On the other hand, the can bottom blow water is introduced into the first processing tank 2A while the operation of the boiler 3 is stopped. Before the introduction of the can bottom blow water, the water in the second treatment tank 2B is discharged to a low water level of a water level detector (not shown). Then, when the operation of the boiler 3 is started, the exhaust gas is mixed and neutralized with the can bottom blow water, and is discharged via the second processing tank 2B. Subsequent operations are the same as those of the concentrated blow water. The operation when the water in the second processing tank 2B does not conform to the drainage standard is the same as that in the first embodiment, and the description is omitted.

As described above, the second embodiment has the first,
Since the second processing tanks 2A and 2B are provided, it is possible to cope with a large-capacity boiler and to perform the neutralization processing more reliably.

Next, a third embodiment, which is another embodiment, of the boiler waste water neutralizing device of the present invention will be described with reference to the drawings. FIG. 5 is an explanatory view schematically showing a configuration of a third embodiment of the neutralization device according to the present invention. The same members as those in the first embodiment and the second embodiment are denoted by the same reference numerals, and overlapping description will be omitted.

The neutralizing device 1 described in the third embodiment is
Boiler 3 and first processing tank 2 described in the second embodiment
A, the auxiliary tank 29
Is provided. That is, as shown in FIG. 5, one end of the can bottom blow pipe 16 is connected to the bottom of the boiler 3, the other end is connected to the auxiliary tank 29, and a can bottom blow solenoid valve 17 is provided on the way. I have. The lower part of the auxiliary tank 29 and the concentration blow pipe 14 are connected by a can bottom blow supply pipe 30, and a check valve 31 and a pump 32 are provided in the middle. The configuration other than the above is the same as in the second embodiment, and a description thereof will be omitted.

According to the boiler waste water neutralizing apparatus 1 having the above-described structure, impurities such as sludge contained in the blow water from the bottom of the can are settled and separated in the auxiliary tank 29, and the impurities are discharged (not shown). , The maintenance (cleaning, etc.) in the first and second processing tanks 2A, 2B can be omitted. Incidentally, the auxiliary tank 29 may be provided in the first embodiment.

[0028]

As described above, according to the present invention, a processing tank for introducing boiler drainage is provided, and an exhaust gas supply pipe, a concentration blow pipe, and a can bottom blow pipe are connected to the processing tank. In the boiler wastewater neutralization device having a configuration in which an overflow pipe and a discharge pipe are connected to a tank, air exhaust means is provided in the exhaust gas supply pipe. the CO ₂ concentration was adjusted by operating the air introduction means, it is possible to adapt the boiler wastewater effluent standards.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram schematically showing a configuration of a first embodiment of a boiler wastewater neutralizing device according to the present invention.

FIG. 2 is an explanatory diagram showing a drainage standard for boiler drainage and a state of the boiler drainage that does not conform to the drainage standard.

FIG. 3 is an explanatory diagram showing a drainage standard for boiler drainage and a state of the boiler drainage that meets the drainage standard.

FIG. 4 is an explanatory view schematically showing a configuration of a second embodiment of the boiler wastewater neutralizing device according to the present invention.

FIG. 5 is an explanatory view schematically showing a configuration of a third embodiment of the boiler wastewater neutralizing device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Neutralizer 2 Processing tank 2A First processing tank 2B Second processing tank 3 Boiler 7 Exhaust gas supply pipe 11 Air introduction means 14 Concentration blow pipe 16 Can bottom blow pipe 18 Overflow pipe 20 Discharge pipe 29 Auxiliary tank

Claims (3)

[Claims] 1. A treatment tank 2 for introducing waste water from a boiler 3.
A boiler waste water neutralizing device having a configuration in which an exhaust gas supply pipe 7, a concentration blow pipe 14, and a can bottom blow pipe 16 are connected to the processing tank 2, and an overflow pipe 18 and a discharge pipe 20 are connected to the processing tank 2. 1. The boiler wastewater neutralization device according to 1, wherein an air introduction means 11 is provided in the exhaust gas supply pipe 7. 2. A treatment tank 2 for introducing waste water from a boiler 3.
And the exhaust gas supply pipe 7 is connected to each of the processing tanks 2, and the concentration blow pipe 14 and the can bottom blow pipe 1 are connected to the processing tank 2 located at the most upstream side.
6 is connected, and the exhaust gas supply pipe 7 is provided with the air introduction means 11 in the boiler waste water neutralization device 1 having a configuration in which the overflow pipe 18 and the discharge pipe 20 are connected to the processing tank 2 located at the most downstream side. A boiler wastewater neutralization device characterized by the following. 3. The bottom of the boiler 3 and the processing tank 2.
Auxiliary tank 29 in the middle of the can bottom blow pipe 16
The boiler wastewater neutralization device according to claim 1 or 2, further comprising: