JPH07976A - Lime solution manufacturing equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a lime aqueous solution production apparatus capable of producing a lime aqueous solution with high efficiency by promoting sedimentation and dissolution of lime. [Structure] In a lime dissolution apparatus having a tubular dissolution tank to which a water supply pipe is connected to the lower part and a lime aqueous solution extraction pipe to the upper part, and which has stirring blades in the lower part of the dissolution tank, the dissolution tank 1 is at least from the upper part to the middle part The melting tank is formed by a bottomed rectangular tube whose cross section is a quadrangle, and which is parallel to one side wall of the melting tank 1 and hangs from the water surface of the melting tank 1 to the range of the intermediate portion. The inside of 1 is partitioned into a main chamber 4 provided with a fluidized bed height suppressing device 12 and a sub chamber 5 for supplying lime, and the fluidized bed height suppressing device 12 is located from the upper part to the middle part of the dissolution tank 1. It consists of a plurality of parallel inclined plates.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing an aqueous lime solution used for improving tap water.

[0002]

2. Description of the Related Art Conventionally, caustic soda injection method, soda ash injection method, slaked lime injection method and the like have been known as measures for preventing red water from tap water, but recently, the slaked lime injection method has been drawing attention. It is said that slaked lime not only raises the pH of water, but also that calcium as a main component is good for health, and that technology has been developed to inject slaked lime not as a powder that easily scatters but as an aqueous solution. Since then, it has been adopted by many water treatment plants.

As an apparatus for continuously producing a slaked lime aqueous solution, for example, an apparatus described in Japanese Patent Publication No. 63-2890 is known. In this known device, a water supply pipe and an insoluble matter discharge port are provided at the bottom of a cylindrical or prismatic dissolution tank, and a horizontally rotating stirring blade is provided immediately above the water supply pipe, and a slaked lime aqueous solution is provided above the tank. It is configured to have an extraction pipe. In this known apparatus, a predetermined amount of slaked lime is supplied from a container bag to the water layer in the dissolution layer by a suction fan or the like, and the production operation of the slaked lime aqueous solution is started after waiting for its natural sedimentation. When the concentration of slaked lime aqueous solution produced decreases,
The operation is stopped once, and slaked lime is newly supplied.

When the operation is stopped, slaked lime is supplied, and the slaked lime powder is restarted after waiting for the natural settling, the slaked lime powder has an apparent specific gravity of about 0.6, and it takes a long time to settle. It has been proposed to prepare two devices and perform a switching operation (Japanese Patent Publication No. 63-35574).

[0005]

As described above, in the above-mentioned known device, not only it takes a long time to supply new slaked lime, but also the rising speed of water in the upper part of the dissolution tank that determines the flow rate of the obtained slaked lime aqueous solution. 0.2 mm at most
/ Sec is the limit. That is, in the above-mentioned known device having no special means other than the agitating blade, if the rising speed of the water is set to the above value or more, the undissolved slaked lime particles are mixed in the slaked lime aqueous solution. Therefore, as for the amount of the aqueous solution produced, the flow rate obtained at the limit value of the ascending speed of 0.2 mm / sec becomes the maximum value.

The present invention aims to shorten the time required for supplying lime by facilitating the sedimentation / dissolution of lime such as slaked lime, enabling continuous supply as necessary, and further undissolved lime in the dissolution tank. To provide a lime aqueous solution manufacturing apparatus that includes a fluidized bed height suppressing device that suppresses a fluidized bed height of particles to increase a rising speed (supply speed) of water, and can sufficiently exhibit the function of the fluidized bed height suppressing device. With the goal. Another object of the present invention is to easily support the facility scale of the water purification plant or the topography of the site.

[0007]

According to the present invention, the above object is to connect a water supply pipe to a lower portion of a cylindrical dissolution tank and a lime aqueous solution extraction pipe to an upper portion thereof, and to provide a stirring blade in a lower portion of the dissolution tank. In the lime melting apparatus having, the melting tank is formed by a bottomed rectangular tube having a quadrangular cross section from at least an upper portion to an intermediate portion, and is parallel to one side wall of the melting tank from the water surface of the melting tank to the intermediate portion. By the partition wall hanging down to the range of, the inside of the dissolution tank is partitioned into a main chamber equipped with a fluidized bed height suppressing device and a sub-chamber for supplying lime, the fluidized bed height suppressing device, This is achieved by comprising a plurality of parallel inclined plates located from the top to the middle. A flat plate, a flat plate with fins, a corrugated plate, or the like is used as the inclined plate.

[0008]

In the device of the present invention, slaked lime or quick lime (hereinafter referred to as "lime") can be used as a raw material, and the lime is charged / supplied on the water surface in the sub chamber. The sub-chamber is provided with a forced contact means, and this lime comes into contact with water to form a slurry and settle.

Lime that is in sufficient contact with water in the sub-chamber settles and rapidly deposits as a slurry on the bottom of the dissolution tank. At the bottom of the dissolution tank, the main chamber and the sub chamber communicate with each other, in which the stirring blades are rotating and water is supplied from the water supply pipe. Therefore, the slurry is stirred to form a fluidized bed, and the lime aqueous solution produced by sufficiently dissolving it in water rises in the main chamber with some undissolved lime particles in the fluidized bed.

When the aqueous solution ascends, it reaches a fluidized bed height suppressing device composed of a plurality of inclined plates and ascends between the inclined plates. Here, the undissolved lime particles in the aqueous solution settle while ascending in the inclined plates. The aqueous solution rises while being separated. Thus, the lime aqueous solution containing almost no undissolved lime is taken out from the lime aqueous solution take-out pipe.

In the present invention, since the melting tank is a rectangular tube having a quadrangular cross section at least in the range where the fluidized bed height suppressing device is located, a plurality of inclined plates forming the fluidized bed height suppressing device are provided. Can be easily manufactured from plate materials having the same width, and almost the entire cross section can be used. Therefore, the flow path of the rising aqueous solution can be formed in a wide range, and the effect of preventing the rising of the undissolved lime particles is great.

In the present invention, if the inner surface of the lower portion of the melting tank in which the stirring blades are located is formed into a substantially inverted conical shape and is continuously transferred to the intermediate portion forming the rectangular tube, the slurry will be deposited in the lower corner. It has a great effect.

Further, depending on the equipment scale of the water purification plant and the site topography, an appropriate number of dissolution tanks can be provided so that the side walls are connected to each other.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

<First Embodiment> FIG. 1 is a vertical sectional view showing the schematic construction of a first embodiment device of the present invention, and FIG. 2 is a partially cutaway perspective view thereof.

In the figure, reference numeral 1 is a rectangular tube-shaped melting tank having a quadrangular cross section. The melting tank 1 is divided into a main chamber 4 and a sub chamber 5 by a partition wall 3 attached to a lid member 2 so as to hang down to an intermediate portion, and the main chamber 4 has a substantially square cross section. There is. In the lower part of the dissolution tank 1, a water supply pipe 6 for supplying water into the dissolution tank 1 from the outside,
Discharge pipes 7 for discharging insoluble materials to the outside at appropriate times are connected via valves. In addition, the dissolution tank 1
A lime aqueous solution take-out pipe 8 is connected to the upper part of the main chamber 4.

The main chamber 4 of the melting tank 1 is provided with a stirring device 11 having a horizontal stirring blade 10 which is rotated by a drive shaft 9 at the bottom of the main chamber 4. Further, a fluidized bed height suppressing device 12 is provided in the main chamber 4 in a range in the height direction of the partition wall 3 that partitions the main chamber 4 and the sub chamber 5. Curved plates 20 are preferably provided at the four corners of the lower portion of the main chamber 4 so that the inner wall of the lower portion has a substantially inverted conical shape. By doing so, the main chamber has a quadrangular cross section at the upper and middle portions, and continuously transitions to a circular shape toward the lower portion, and there is no corner at the position of the stirring blade 10. Instead of the curved plate, a flat plate close to the curved plate may be attached as a swash plate. Further, the melting tank 1 itself may be formed in a substantially inverted conical shape in the lower portion.

The fluidized bed height suppressing device 12 is preferably composed of two or more inclined plates having the same width B and arranged in parallel at substantially equal intervals as shown in the figure. However, with respect to the length in the vertical direction, the length near the side wall of the melting tank is shortened depending on the part. It is sufficient for the inclined plates to incline in the same direction, but it is more preferable that the inclined directions are alternately reversed to form two or more stages. The interval between the parallel inclined plates is preferably about 5 to 70 mm. In any case, the inclined plate of this embodiment can be easily made of a plate material having a quadrangular plane, and the production cost is significantly low,
Most of the cross-sectional area of the main chamber 4 can be occupied, and the effective area is greatly increased.

The lid member 2 of the sub-chamber 5 is provided with a lime charging hopper 14 via a valve 15 and also with a spraying device 16 for preventing scattering of the lime charged on the water surface. There is.

A rotary blade 18 as a forced contact means is provided in the sub chamber 5 so as to stir the water near the water surface. The rotor 18 may simply stir water,
It is preferred to produce a downward flow 19 with stirring.

In the sub-chamber 5, for example, as shown in FIG. 2, the charging hopper 14 and the spray device 16 can be collectively arranged in the central portion 5A, and in this case, the auxiliary elements are provided in the spaces 5B on both sides. For example, an air compressor, a dehumidifier, etc. can be housed, and the shape of the melting tank in the shape of a rectangular tube can be effectively utilized.

In the apparatus of this embodiment having such a structure, the lime aqueous solution is manufactured as follows.

A predetermined amount of lime is dropped from the hopper 14 onto the water surface of the sub chamber 5. At this time, the spray 16 prevents the scattered lime particles from escaping to the outside air. Immediately after being dropped, the lime that does not dissolve and floats on the water surface is agitated by the rotary blades 18 and is forcibly brought into contact with water to form a slurry, which promotes sedimentation. The above settling is further promoted if the rotor blades 18 generate the downward flow 19.

The settled slurry is deposited at the bottom of the dissolution tank 1, where it is stirred by the stirring blade 10 to form a fluidized bed, and further, contacted with the water supplied from the water supply pipe 6. , Dissolution progresses and becomes a lime aqueous solution.

Since the main chamber 4 is supplied with water from the water supply pipe 6, the lime aqueous solution rises in the main chamber 4. that time,
The rising lime aqueous solution contains undissolved lime particles in the fluidized bed, which also rises.

The lime aqueous solution containing the undissolved lime particles gradually rises in the flow path between the inclined plates, but the undissolved lime particles having a high specific gravity with respect to the lime aqueous solution rises to the inclined plate above the flow path. Is suppressed and falls, and the lime aqueous solution continues to rise.

Thus, a lime aqueous solution containing almost no undissolved lime particles near the water surface of the main chamber 4 is taken out from the take-out pipe 8.

<Second Embodiment> Next, a second embodiment will be described with reference to FIG. In the figure, the same parts as those in FIG. 1 in the above-described first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The first embodiment shown in FIGS. 1 and 2 is composed of one melting tank, but this embodiment is characterized in that a plurality of melting tanks are integrally formed.

The apparatus of this embodiment has four melting tanks of the same construction.
It is formed by connecting I, II, III, and IV so that their sidewalls face each other. Each of these melting tanks I, II, III and IV has exactly the same structure as the single melting tank described in the first embodiment.

In this embodiment, the number of the dissolving tanks is selected according to the scale of the water purification plant, and the connecting direction is determined according to the topography of the site. Regarding the connection, they may be connected in series as shown by the solid line in FIG. 3 or may be connected in an L shape as shown by the chain double-dashed line in the figure.

Further, regardless of the method of connecting a plurality of melting tanks of the first embodiment, for example, in the case of FIG. 3, one apparatus having a rectangular shape having a long planar shape is formed so as to have four melting tanks. You may. In any case, since the cross section of the melting tank is rectangular, it is possible to integrate a plurality of melting tanks very easily.

[0033]

As described above, according to the present invention, the sub-chamber is partitioned from the main chamber at least in the water surface area, and lime to be introduced into the sub-chamber may be mixed in the lime aqueous solution taken from the main chamber. Since there is no lime, there is no risk of lime depositing on the fluidized bed height suppressing device, and the lime aqueous solution can be continuously produced, and productivity can be improved. In addition, in the fluidized bed height suppression device consisting of multiple inclined plates, the cross-section of the dissolution tank has a quadrangular shape, so the inclined plates are all quadrangular and easy to manufacture. The suppression effect of is improved. Furthermore, since an appropriate number of melting tanks can be connected according to the scale and topography of the water purification plant, only one kind of melting tank needs to be designed and manufactured, which greatly improves the adaptability.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a schematic configuration of a first embodiment device of the present invention.

2 is a partially cutaway perspective view of the device of FIG. 1. FIG.

FIG. 3 is a perspective view showing a schematic configuration of a second embodiment device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dissolution tank 3 Partition wall 4 Main chamber 5 Sub-chamber 6 Water supply pipe 8 Lime aqueous solution extraction pipe 10 Stirring blade 12 Fluidized bed height suppression device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kotoshi Sudo 33-1 Shiomidai, Yosawa, Nakoso-cho, Iwaki, Fukushima Prefecture

Claims (5)

[Claims] 1. A lime dissolution apparatus having a tubular dissolution tank to which a water supply pipe is connected to a lower portion and a lime aqueous solution extraction pipe to an upper portion, respectively, and which has a stirring blade in a lower portion inside the dissolution tank, wherein the dissolution tank is at least from an upper portion to an intermediate portion. The inside of the melting tank is formed by a partition wall that is formed by a bottomed rectangular tube having a quadrangular cross section and that extends parallel to one side wall of the melting tank from the water surface of the melting tank to the range of the intermediate portion. Is partitioned into a main chamber equipped with a fluidized bed height suppressing device and a sub-chamber for supplying lime, and the fluidized bed height suppressing device is composed of a plurality of parallel inclined plates located in the middle part from the upper part of the melting tank. An apparatus for producing an aqueous lime solution, which is characterized by being formed. 2. The apparatus for producing a lime aqueous solution according to claim 1, wherein the main chamber has a curved plate whose lower portion forms an inner wall of a substantially inverted conical shape at a corner portion. 3. The lime aqueous solution manufacturing apparatus according to claim 1, wherein the lower portion of the dissolution tank has a substantially inverted conical shape. 4. The lime aqueous solution production apparatus according to claim 1, wherein a plurality of dissolution tanks are provided so that adjacent side walls are connected to each other. 5. The apparatus for producing an aqueous lime solution according to claim 4, wherein the adjacent side walls of the plurality of dissolution tanks are formed as a common partition.