JPH10328678A - Neutralization device for boiler blow-down water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a neutralization device for boiler blow-down water in which boiler blow-down water is continuously neutralized and treated regardless of its kind (concentrated blow-down water, blow-down water of a boiler bottom) and usage of water for cooling or dilution is inhibited to the necessary lower limit. SOLUTION: The neutralization device of boiler blow-down water is equipped with a treatment tank 2 for introducing blow-down water of a boiler 1. An exhaust gas supply pipe 3 for supplying the exhaust gas of the boiler 1 is connected to the treatment tank 2. An overflow pipe 4 and a discharge pipe 5 are connected to the treatment tank 2. When concentrated blow-down water of the boiler 1 is introduced into the treatment tank 2, increased water is discharged from the overflow pipe 4. Before blow-down water of a boiler bottom in the boiler 1 is introduced into the treatment tank 2, water in the treatment tank 2 is discharged to the prescribed water level through the discharge pipe 5. Further, the neutralization device of boiler blow-down water is equipped with a cooling means of blow-down water and also with a means for performing cooling or dilution by supplying water to boiler blow-down water when temperature or pH of boiler blow-down water after neutralization treatment reaches preset value or above.

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,
It is necessary to perform neutralization treatment at the time of drainage. For example, there is an apparatus for injecting and neutralizing carbon dioxide gas, but this apparatus requires carbon dioxide gas, so that the running cost increases.

[0003] There is also an apparatus for storing boiler wastewater in a treatment tank, mixing the wastewater from the boiler with the wastewater, and performing a batch-type neutralization treatment. In this apparatus, it is necessary to increase the tank capacity of the processing tank, and to inject a large amount of cooling water in order to cool the temperature to 45 ° C. or lower, which is the temperature based on sewerage.

[0004]

SUMMARY OF THE INVENTION The present invention is intended to continuously neutralize boiler wastewater regardless of its type (concentrated blow water, can bottom blow water) and to reduce the amount of water used for cooling or dilution. The purpose of the present invention is to provide a boiler wastewater neutralization device that is minimized.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and is directed to a neutralization apparatus for mixing boiler wastewater with boiler exhaust gas to neutralize the boiler wastewater. The first feature is that the blow water is selectively treated. Further, the present invention includes a processing tank for introducing boiler wastewater, connecting an exhaust gas supply pipe for supplying boiler exhaust gas to the processing tank, connecting an overflow pipe and a discharge pipe to the processing tank, and condensing the boiler. When the blow water is introduced into the processing tank, the increased water is discharged from the overflow pipe, and before the boiler bottom blow water is introduced into the processing tank, the water in the processing tank is drained to a predetermined water level. The second feature is that the air is discharged from the outlet. Further, the present invention is a neutralization device for mixing and neutralizing boiler waste gas with boiler waste water, the waste water cooling means being provided, and the temperature or pH of the boiler waste water after the neutralization treatment is not less than a preset value. A third feature is that a means is provided for supplying or cooling or diluting water to the boiler wastewater when the water is discharged, and a fourth feature is that the wastewater cooling means is a water supply pipe of the boiler.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A treatment tank for introducing boiler wastewater is provided. An exhaust gas supply pipe for supplying boiler exhaust gas is connected to the treatment tank, and the boiler wastewater is mixed with boiler exhaust gas for neutralization. Alkaline boiler wastewater is neutralized by acidic components (such as carbon dioxide) in boiler exhaust gas. The boiler wastewater includes concentrated blow water that discharges concentrated can water during the boiler combustion operation and can bottom blow water that is discharged from the bottom of the can body when the boiler is stopped.

[0007] An overflow pipe and a discharge pipe are connected to the processing tank. The concentrated blow water of the boiler is introduced into the processing tank during the combustion operation of the boiler, and the exhaust gas generated by the combustion is mixed and neutralized. The increased water in the treatment tank is discharged from the overflow pipe and continuously neutralizes boiler wastewater.

The bottom blow water of the boiler is introduced into the processing tank while the operation of the boiler is stopped. Before the introduction, the water in the treatment tank is drained from the discharge pipe to a predetermined water level, and after the water is discharged, the 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 proceeds to the above-described process of treating the concentrated blow water, and the concentrated blow water and the can bottom blow water can be selectively treated. That is, the neutralization process can be continuously performed by one system regardless of the type of blow.

[0009] The treatment tank is provided with a drainage cooling means for cooling the boiler wastewater to a predetermined temperature or less before discharging it. As the drainage cooling means, a water supply pipe of the boiler is used, and a water supply pipe is arranged in the treatment tank, and the boiler water is cooled by the water supply of the boiler. This configuration also has the function of recovering the heat of the wastewater by supplying water. As the drain cooling means, means other than the water supply pipe can be used. Further, the drainage cooling means can be provided at an upstream position or a downstream position of the processing tank.

[0010] A temperature detector for detecting the temperature of the boiler wastewater after the neutralization treatment and a pH detector for detecting the pH of the boiler wastewater after the neutralization treatment are provided, so that the temperature or the pH of the boiler wastewater exceeds a predetermined value. When this happens, water is supplied to the boiler wastewater to cool or dilute it. This water goes into the treatment tank,
It supplies to one or more places among an upstream position of a processing tank, and a downstream position of a processing tank. The temperature detector and the pH detector may be provided with only one of them. The configuration that lowers the temperature of the boiler wastewater by boiler feedwater does not normally require cooling water, and even if the temperature or pH of the boiler wastewater becomes high, supplying water to cool or dilute it ensures reliable and safe operation. Neutralization can be performed. The water to be cooled or diluted serves as a backup function to be used only when necessary, and can significantly reduce the amount of water used.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

An economizer 8 is provided in an exhaust gas passage 7 of the boiler 1, and one end of an exhaust gas supply pipe 3 is connected to a downstream position of the economizer 8. The other end of the exhaust gas supply pipe 3 is connected to the treatment tank 2 for introducing boiler drainage,
The boiler exhaust gas is mixed with the boiler wastewater in the processing tank 2. The exhaust gas supply pipe 3 is provided with a drain separator 10 and an exhaust gas pump 11.

The boiler 1 is provided with a separator 12.
4 are connected. The tip of the concentration blow pipe 14 is connected to the processing tank 2. The concentration blow pipe 14 is provided with a concentration blow solenoid valve 15.

A bottom blow tube 16 is connected to the bottom of the boiler 1. 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 manual valve 17 and a can bottom blow electric valve 18 in parallel.

An overflow pipe 4 is provided above the processing tank 2.
And a discharge pipe 5 is connected to the lower part. The overflow pipe 4 is used to supply the concentrated blow water of the boiler 1 to the treatment tank 2
It has the function of discharging the increased water when introduced into the vessel. The discharge pipe 5 has an operation of discharging water in the processing tank 2 to a predetermined water level before introducing the bottom blow water of the boiler 1 into the processing tank 2. The discharge pipe 5 is provided with a motorized discharge valve 19. Further, the processing tank 2 is provided with a water level detector 20 including a high water level detection unit H and a low water level detection unit L.

The overflow pipe 4 and the discharge pipe 5 are joined and connected to a water quality detection tank 21. The water quality detection tank 21 includes a temperature detector 22 and a pH detector 23, and detects the temperature and pH of the boiler wastewater.

A water supply pipe 24 is connected to the junction of the overflow pipe 4 and the discharge pipe 5. This water supply pipe 24
Is provided with a water supply pump 25.

The water supply pipe 6 of the boiler 1 has a water supply pump 26 and is connected to the economizer 8, and supplies water to the can of the boiler 1 via the economizer 8. A cooling heat exchange section 29 in the middle of the water supply pipe 6 is disposed in the processing tank 2 and functions as a drain cooling means for cooling boiler drain.
Further, the cooling heat exchange unit 29 also has a function of recovering heat of the boiler wastewater.

A partition plate 27 is provided in the processing tank 2, and the inside of the processing tank 2 is divided into an inflow side and an outflow side while the upper and lower portions are communicated with each other. By doing so, it is possible to prevent the high-temperature water on the inflow side and the low-temperature water on the outflow side from diffusing and mixing, and to reliably discharge only the low-temperature water. In addition, the boiler drainage flows into the treatment tank 2 and passes below the partition plate 27 to form the overflow pipe 4.
The time required for mixing and neutralizing the exhaust gas in the flow flowing out of the exhaust gas can be reliably secured. Further, the cooling heat exchange section 29 is disposed from the outflow side to the inflow side with the partition plate 27 interposed therebetween, and the water supply pipe 6 is disposed in a direction opposite to the flow of water in the processing tank 2. By doing so, the cooling effect of the boiler drainage is further enhanced.

Exhaust gas pump 11, motor valve for can bottom blow 1
8. Electric discharge valve 19, water level detector 20, temperature detector 2
2. The pH detector 23 and the water supply pump 25 are connected to a control device 28 via electric wiring.

The 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 neutralization process will be described. The concentrated blow water flows into the processing tank 2 by receiving a command from the operation control device (not shown) of the boiler 1 and opening the concentrated blow electromagnetic valve 15. Upon receiving the water presence signal from the high water level detector H of the water level detector 20, the exhaust gas pump 11 operates. The exhaust gas pump 11 operates in synchronization with the combustion of the boiler 1. The exhaust gas of the boiler 1 is mixed and neutralized, and the heat exchange unit 29 for cooling is used.
The boiler waste water cooled by the above is discharged from the overflow pipe 4 by the increased water.

The boiler wastewater flows into the water quality detection tank 21 via the overflow pipe 4 and is supplied to the water quality detection tank 21.
Outflow from 1 In the water quality detection tank 21,
The temperature and pH of the boiler wastewater are detected by the temperature detector 22 and the pH detector 23. When the temperature is 40 ° C. or higher or the pH is 8.6 or higher, the water supply pump 25 is operated to supply water to cool or dilute. This water is supplied to the water quality detection tank 21 through the supply pipe 24, but a part of the water is supplied from the overflow pipe 4 to the treatment tank 2. When the temperature is over 45 ° C or the pH is over 9.0,
Raise an alarm.

Next, the neutralization of the bottom blow water will be described. Can bottom blow water is also automatically operated by automatically operating a valve to discharge half of the can water.
It is divided into water and manual can bottom blow (all blow) water, which is operated manually to discharge all the can water. The auto bottom blow (semi-blow) water is neutralized as follows. Boiler 1
Turn off the combustion switch (not shown) of
The half blow switch (not shown) of the control device 28 is turned ON. Then, the electric discharge valve 19 is opened, and the water in the processing tank 2 is discharged. When the water level in the processing tank 2 drops to the low water level detection unit L of the water level detector 20, the electric discharge valve 19 is closed. Next, the can bottom blow electric valve 18 is opened, and can bottom blow water is introduced into the treatment tank 2. When the water level in the processing tank 2 rises to the high water level detection portion H of the water level detector 20, the electric valve 18 for can bottom blowing is closed (end of half blowing). Then, when the operation of the boiler 1 is started, the exhaust gas pump 11 is operated to mix the exhaust gas with the can bottom blow water. The subsequent operation is the above-described neutralization processing operation of the concentrated blow water.

The manual can bottom blow (all blow) water is neutralized as follows. The combustion switch (not shown) of the boiler 1 is turned off, and all the blow switches (not shown) of the control device 28 are turned on. Then, the electric discharge valve 19 is opened, and the water in the processing tank 2 is discharged.
When the water level in the processing tank 2 drops to the low water level detection section L of the water level detector 20, the electric discharge valve 19 closes and the all-blow permission lamp (not shown) is turned on. After confirming that all the blow permission lamps are turned on, open the manual valve 17 for can bottom blow,
The can bottom blow water is introduced into the treatment tank 2. After the entire blow, the manual valve 17 for can bottom blowing is closed, and when the operation of the boiler 1 is started, the exhaust gas pump 11 operates to mix the exhaust gas with the can bottom blow water. The subsequent operation is the above-described neutralization processing operation of the concentrated blow water.

[0025]

According to the present invention, as described above, according to the first or second aspect, regardless of the type of blow,
The neutralization treatment can be continuously performed by one system. According to the configuration of claim 3, since a drain cooling unit for lowering the temperature of the boiler drain is provided, it is not necessary to inject a large amount of cooling water into the boiler drain, and even if the temperature or pH of the boiler drain becomes high, the water By supplying and cooling or diluting, reliable and safe neutralization treatment can be performed. This water acts as a backup function used only when necessary, and can significantly reduce the amount of water used. According to the configuration of claim 4, since the feed pipe of the boiler is used as the drain cooling means, the boiler drain can be cooled with a low cost and simple configuration, and heat recovery from the boiler drain can also be performed. .

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Boiler 2 Processing tank 3 Exhaust gas supply pipe 4 Overflow pipe 5 Discharge pipe 6 Water supply pipe 7 Exhaust gas passage 8 Energy saving device 9 Nozzle 10 Drain separator 11 Exhaust gas pump 12 Separator 13 Downcomer 14 Concentration blow pipe 15 Electromagnetic valve for concentration blow 16 Can bottom blow pipe 17 Can bottom blow manual valve 18 Can bottom blow electric valve 19 Discharge electric valve 20 Water level detector 21 Water quality detection tank 22 Temperature detector 23 pH detector 24 Water supply pipe 25 Water supply pump 26 Water supply pump 27 Partition plate 28 Controller 29 Heat exchange unit for cooling

Claims (4)

[Claims] 1. A boiler wastewater, comprising: a neutralization apparatus for mixing boiler wastewater with boiler wastewater to neutralize the boiler wastewater, wherein the concentrated blowwater and the can bottom blowwater are selectively treated. Neutralization equipment. 2. A treatment tank 2 for introducing waste water from a boiler 1.
An exhaust gas supply pipe 3 for supplying exhaust gas from the boiler 1 is connected to the processing tank 2, an overflow pipe 4 and an exhaust pipe 5 are connected to the processing tank 2, and the concentrated blow water of the boiler 1 is supplied to the processing tank 2. When the water is introduced into the processing tank 2, the increased water is discharged from the overflow pipe 4, and the water in the processing tank 2 is discharged from the discharge pipe 5 to a predetermined water level before the can bottom blow water of the boiler 1 is introduced into the processing tank 2. A boiler wastewater neutralizing device, characterized in that it is configured to discharge. 3. A neutralization apparatus for mixing and neutralizing boiler wastewater with boiler wastewater, comprising a wastewater cooling means, wherein the temperature or pH of the boiler wastewater after the neutralization treatment is equal to or higher than a preset value. A boiler wastewater neutralization device, comprising means for supplying water to the boiler wastewater for cooling or diluting when the water is discharged. 4. The boiler waste water neutralizing device according to claim 3, wherein the waste water cooling means is a water supply pipe 6 of the boiler 1.