JPH10328542A - Method for dissolving quick line and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively and efficiently neutralize a waste acid by preventing the generation of dust in the case of using quick lime inexpensive as a neutralize for waste acid treatment. SOLUTION: This quick lime dissolving device is provided with a helmet shaped member 7 receiving a granular quick lime discharged and falling down from a quick lime charging pipe 4, a funnel shaped member 8 provided to surround the helmet shaped member 7 and a liquid injection pipe 9 for injecting a solution inside of the funnel shaped member 8 in the tangential direction of the funnel shaped member 8. The solution injected to the funnel shaped member 8 from the liquid injection pipe 9 spirally flows and forms swirling flow and the quick lime falling down from the helmet shaped member 7 is rapidly involved in the swirling flow and dissolved without generating dust.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for dissolving lime used for neutralizing acid waste liquor generated in an ironworks.

[0002]

2. Description of the Related Art Slaked lime, which is safe and easy to handle, has been mainly used for neutralizing acid waste liquid such as pickling waste liquid. Recently, however, quick lime has been used to reduce the cost of neutralization treatment. It is being used. These limes are used in the form of a lime solution in which powdery and granular materials are dissolved in water.However, when quicklime is dissolved in water, a large amount of quicklime is generated due to the generation of steam due to heat generation, which blocks pipes and the like. There's a problem.

[0003] In order to solve such a problem, a method of covering around a charging pipe for charging quicklime into a melting tank with a cover is known. However, dust generated in the cover adheres to the inner surface of the cover. Cleaning requires a lot of labor. Also, if the inside of the melting tank is agitated to promote the melting, the insufficiently dissolved quicklime will form a dumpling in the melting tank and flow out of the cover, then collapse and become dust, and a bug to capture the dust. Filters are prone to clogging and require frequent replacement.

As a method for suppressing the generation of dust, for example, according to Japanese Patent Application Laid-Open No. Sho 64-30694, 60% or less of quicklime, 23 to 83% of slaked lime, and 7 to 25% of calcium carbonate are used as neutralizing agents. There is known a method of using the above. However, 100% of quicklime cannot be used in this method.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a low-cost and efficient waste acid neutralization treatment by preventing the generation of dust when inexpensive quicklime is used as a neutralizing agent for waste acid treatment. The purpose is to do.

[0006]

According to the present invention, there is provided a method for dissolving quicklime in a method for supplying and dissolving powdered quicklime powder in water to form a lime solution. Wherein the swirling flow is formed, and the quicklime is supplied to the swirling flow.

[0007] The quicklime dissolving apparatus further comprises a chin-shape member for receiving powdery granulated lime powder discharged from the quick-lime charging pipe, falling, a funnel-like member provided to surround the chinshade-like member, and a tangent to the funnel-like member. A liquid injection pipe for injecting water or lime solution into the funnel-shaped member in the direction.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method and apparatus of the present invention will be described in detail with reference to an apparatus example shown in the drawings. In FIG. 1, a cutout feeder 2 for cutting out quicklime is provided at a lower end of a storage tank 1 for accommodating powdered and granular quicklime C, and a quicklime feed pipe having a cutout valve 3 on an outlet side of the cutout feeder 2. 4 are provided. Quicklime C in the storage tank 1
Can be cut out from the quicklime input pipe 4 by the screw 6 rotating.

As shown in FIGS. 2 and 3 in an enlarged manner, a funnel-shaped member 8 is provided at a lower end of the quicklime input pipe 4.
The umbrella-shaped member 7 is provided so as to be supported by the funnel-shaped member 8. A liquid injection pipe 9 for injecting water or lime solution is provided at an upper part of the funnel-shaped member 8, and a liquid injection port 9a of the liquid injection pipe 9 is opened inside the funnel-shaped member 8 and has a funnel shape. It is oriented in the tangential direction of the member 8. From the liquid injection pipe 9,
Water or lime solution for dissolving quicklime is squirted from the tangential direction of the funnel-shaped member 8 and swirls along the inner peripheral surface of the funnel-shaped member 8, thereby making a spiral swirl on the inner peripheral surface of the funnel-shaped member 8. A stream W is formed.

The quicklime C that has fallen from the quicklime input pipe 4 to the garbage-like member 7 falls into the spiral vortex W from the periphery thereof while being uniformly dispersed by the garbage-like member 7, and is quickly caught in the whirlpool W. While moving downward, the generation of lime dust is suppressed and sent to the melting tank 10 shown in FIG. The dissolving tank 10 is covered with a lid 11 and provided with a stirrer 12 and a liquid level meter 13, and the lime solution in the dissolving tank 10 is stirred and mixed. The lid 11 of the melting tank is provided with an exhaust duct 14 for sucking lime dust generated in the tank, and the exhaust duct 14 is connected to a wet scrubber 15 for capturing and collecting lime dust.

The wet scrubber 15 includes a multistage perforated plate 16, a mist separator (eliminator) 17, a washing nozzle 19 provided via a circulation pump 18, a washing nozzle 22 having a makeup water pipe 20 and a makeup water valve 21, An exhaust duct 24 containing an exhaust fan 23 is provided. An inverted pyramid-shaped circulating liquid storage tank 25 for storing water or lime solution is provided at the lower end of the wet scrubber 15.
, A liquid temperature gauge 26 and a liquid level meter 27 are provided.

At the lower end of the circulating liquid storage tank 25, a valve 2 is provided.
A suction part having 8 and 29 is provided, and the suction part is connected to the liquid injection pipe 9 shown in FIGS. An exhaust pipe 31 having a sealing valve 30 is provided between the wet scrubber 15 and the storage tank 1 so that lime dust generated in the storage tank 1 is taken in below the wet scrubber 15. Exhaust pipe 3
A dust discharge valve 34 connected to the cyclone 33 and the storage tank 1 is provided between 1 and 32. The storage tank 1 is provided with a quicklime receiving pipe 46 and a plug 47 for the receiving pipe.

Above the melting tank 10, a tank 35 for measuring the temperature of the lime solution is provided, and the tank is divided into three chambers. The first chamber 35a on the wet scrubber 15 side is partitioned by a separator 36 communicating with the lower part, and a solution pumping tube 37 for pumping the lime solution in the dissolving tank 10 is provided on the wet scrubber side via a pump 38. A liquid thermometer 39 is provided on the side opposite to the wet scrubber.

A valve 4 is provided in the second chamber 35b of the liquid temperature measuring tank.
A solution discharge pipe 41 having 0 is provided to be connected to the lid 11 of the dissolution tank, and a solution discharge pipe 42 for discharging the lime solution to the solution storage tank 43 is provided in the third chamber 35c. The solution storage tank 43 is provided with a liquid level meter 44 and a stirrer 45.

Next, the operation of the above-described apparatus will be described mainly with reference to FIG.
This will be described with reference to FIG. When this apparatus is newly used, the circulating solution storage tank 25 shown in FIG. 1 is filled with water supplied from the makeup water pipe 20. Circulating solution storage tank 2
When the valves 28 and 29 of No. 5 are opened, the water in the circulating solution storage tank 25 is injected into the funnel-shaped member 8 from the liquid injection pipe 9 shown in FIGS. Since the liquid injection pipe 9 is provided in the tangential direction of the funnel-shaped member 8, the water discharged from the liquid injection pipe 9 flows along the inner peripheral surface of the funnel-shaped member 8 to form a swirling flow W. , And falls into the dissolving tank 10 in a vortex shape.

On the other hand, the powdery lime in the storage tank 1 shown in FIG. 1 is cut out by the cut-out feeder 2 and falls from the quick lime charging pipe 4 to the chin-shape member 7, and the gin-shape member shown in FIGS. 7 are uniformly distributed in the circumferential direction and fall into the swirling flow W. The quicklime that is uniformly dispersed and falls in the swirling flow W is immediately caught in the swirling flow W, so that the generation of dust is suppressed, and the quicklime flows down into the melting tank 10 and is prevented from forming a dumpling in the melting tank 10.

In the dissolving tank 10, the lime solution rises to near 60 ° C. (when the concentration is 8%) due to the reaction between water and quicklime, and steam containing lime dust is generated. This water vapor is sucked by the exhaust fan 23 below the wet scrubber 15 through the exhaust duct 14 so that
The dust generated at 0 is prevented from entering the funnel-shaped member 8 to block the quicklime input pipe 4 and the cutout valve 3.

In the wet scrubber 15, the dust passing through the exhaust duct 14 rises toward the multi-stage perforated plate 16. The water in the circulating solution storage tank 25 is pumped up by the circulating pump 18 and is supplied from the washing nozzle 19 into a water film form to the perforated plates 16 in a plurality of stages. Dust is captured by the water film and falls into the circulating solution storage tank 25. .

The droplets including dust generated in the perforated plate 16 are:
The air is sucked up by the exhaust fan 23 and captured by the mist separator 17. The dust captured by the mist separator 17 is washed away by the washing water of the makeup water pipe 20 ejected from the washing nozzle 22. With the capture of dust, the water in the circulating solution storage tank 25 becomes a lime solution,
The liquid is supplied to the liquid injection pipe 9 through the pipe 9.

The liquid level in the circulating liquid storage tank 25 is controlled by controlling the make-up water valve 21 so that the value detected by the liquid level meter 27 falls within a predetermined range.
The control of the liquid level at 0 is performed by adjusting the valve 40 so that the value detected by the liquid level meter 13 falls within a predetermined range.

Since the temperature of the lime solution is proportional to the concentration, the concentration is controlled by controlling the temperature of the lime solution.
The concentration of the dissolving tank 10 is controlled by controlling the motor 5 according to the liquid temperature measured by the liquid thermometer 39, and the concentration of the circulating liquid storage tank 25 is controlled according to the liquid temperature measured by the liquid thermometer 26. This is performed by controlling the water valve 21.

When the quicklime is to be received in the storage tank 1, the dust discharge valve 34 is opened and the lime dust is captured by the cyclone 33 and collected in the storage tank 1. Exhaust pipe 31
The dust inside is drawn into the wet scrubber 15 by opening the sealing valve 30 and activating the exhaust fan 24. The extraction valve 3 is closed except when the quick lime is cut out, and the stopper 47 is attached to the quick lime receiving pipe 46 except when the quick lime is received, and the sealing valve 30 of the exhaust pipe 31 is closed to keep the storage tank 1 in a closed state. .

[0023]

According to the present invention, in a method of supplying and dissolving powdery and granular lime into water to form a lime solution, a swirling flow is formed, and the quicklime is uniformly dispersed and supplied to the swirling flow. With such a configuration, quicklime is immediately caught in the swirling flow and supplied to the melting tank. As a result, it is possible to suppress the generation of lime dust generated when quick lime is supplied to water, and to prevent clogging of pipes and the like due to the dust and deterioration of the environment.

Further, the lime dust generated in the dissolving tank or the like is captured by a wet scrubber, and the lime solution generated by the capture is used for dissolving quick lime, so that the lime dust can be efficiently recovered. Further, since the supply amount of quicklime is adjusted according to the temperature (concentration) of the lime solution, it is possible to prevent dust from being generated due to overheating of the lime solution.

[Brief description of the drawings]

FIG. 1 is an overall view (flow diagram) of a quicklime dissolving apparatus according to an embodiment of the present invention.

FIG. 2 is a partially enlarged view (side sectional view) of FIG.

FIG. 3 is a cross-sectional plan view taken along line XX of FIG. 2;

[Explanation of symbols]

1; quicklime storage tank 2; cutting feeder
3; cut-off valve 4; quick lime inlet pipe 5; motor
6; Screw 7; Jin-shape member 8; Funnel-shaped member
9; liquid injection tube 10; dissolution tank 11; lid of dissolution tank
12; agitator 13; liquid level meter 14; exhaust duct
15; wet scrubber 16; perforated plate 17; mist separator
18; circulation pump 19; washing nozzle 20; makeup water pipe
21; makeup water valve 22; washing nozzle 23; exhaust fan
24; exhaust duct 25; circulating fluid storage tank 26; liquid thermometer
27; liquid level meter 28; valve 29; valve
30; sealing valve 31; exhaust pipe 32; exhaust pipe
33; cyclone 34; dust discharge valve 35; tank for measuring liquid temperature
36; separator 37; solution suction pipe 38; pump
39; liquid thermometer 40; valve 41; liquid discharge pipe
42; liquid discharge pipe 43; solution storage tank 44; liquid level meter
45; Stirrer 46; Quicklime receiving pipe 47; Plug of receiving pipe
C: quicklime W: swirling flow

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C02F 1/66 530 C02F 1/66 530A

Claims (2)

[Claims] 1. A method for supplying and dissolving powdery and granular lime powder in water to form a lime solution, wherein a swirling flow of water or lime solution flowing in a swirl is formed, and the quicklime is supplied to the swirling flow. A quicklime dissolving method characterized by the following. 2. A girder-shaped member (7) for receiving powdered granulated lime discharged from a quick-lime charging pipe (4) and a funnel-shaped member (8) provided so as to surround the girder-shaped member (7). ,
Funnel-shaped member (8) tangential to funnel-shaped member (8)
And a liquid injection pipe (9) for injecting water or lime solution into the inside of the device.