JPH08192077A - Centrifuge - Google Patents

Abstract

PURPOSE: To prevent dry solid matter of filtrate from being mixed in cake to cause deterioration and variation in quality of the cake in solid-liquid separation. CONSTITUTION: In a centrifuge in which slurry fed into a basket 2 driven and rotated by a motor in a casing 1 is subjected to solid-liquid separation to discharge cake from a discharge port 6 and on the other hand, filtrate is discharged from a drain port 7, on the peripheral edge of a ceiling of the casing and on a lower frame 1a of the casing below the bottom part of the basket, washing pipes 13, 16 in the shape of a ring are arranged to wash off filtrate stuck on the upper part of the casing and the bottom part of the basket. On the lower side of the casing, a filtrate discharge port 18 projecting in the shape of a ring from the inner periphery of the casing and opened upwards is formed. The greater part of the filtrate passing between the inner wall of the casing and the basket is discharged to reduce the stuck quantity to the bottom part of the basket. The gasket 2 facing the discharge port 6 is provided with a blade 22 to cause a gas flow directed outwards from the discharge port 6, preventing the filtrate carried by the gas flow from flowing into the discharge port.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifuge for supplying a slurry into a basket which is rotationally driven, and separating and extracting solids from the slurry, and a centrifuge for removing a crystalline organic compound from a solvent. Regarding the method of separation.

[0002]

2. Description of the Related Art FIG. 1 shows an example of this type of centrifugal separator, in which a cylindrical basket 2 which is rotationally driven by a motor is arranged in a casing 1 and which is rotationally driven at a high speed from a raw material supply port 3. The slurry supplied to the inside 2 hits the dispersion plate 4 and scatters around, and is separated into solid and liquid in the basket 2, and the filtrate is discharged from the drain 7 through the casing outside the basket, while the solid content is The cake layer 5 is gradually accumulated inside the basket, and thereafter, the cake layer 5 is periodically scraped off by the scraping blade 8 to be dropped and discharged from the discharge port 6. In the figure, reference numeral 9 is a gas outlet to the atmosphere.

[0003]

The filtrate discharged from the basket 2 hits the inner wall of the casing and scatters, adheres to the upper part of the casing and the bottom of the casing, and is then dried to dryness. This is sometimes caused by the gas flow in the casing, or the discharge port. 6 may fall into the 6, resulting in undesirable results in some applications, such as when using cake as a product. Especially in the case of crystallizing and refining crystalline organic compounds such as terephthalic acid, hydroquinone, resorcin, etc., when separating the crystals from the slurry using a centrifuge, the dried filtrate does not only contain a large amount of impurities, but sometimes It may have deteriorated due to aging,
If such a dry solid matter or a deteriorated matter is mixed in the crystal, the product quality will be deteriorated or changed.

The filtrate discharged from the basket is discharged from the discharge port 6.
The same problem occurs when it flows into. That is, if the linear velocity of the filtrate discharged from the basket increases significantly,
The filtrate comes to entrain a large amount of gas, and the gas separated from the filtrate at the time of discharging the filtrate flows into the discharge port 6 together with the liquid containing a large amount of impurities, which causes deterioration or fluctuation of the product quality. Will bring.

The present invention aims to solve the above problems.

[0006]

As one of the centrifuges for achieving the above-mentioned object, the present invention is directed to one of a casing upper portion, a basket seat portion and a casing bottom portion.
Preferably, a cleaning device for spraying the cleaning liquid on the upper side of the casing or on the basket seat portion, preferably on the opposite side, is installed in the opposite direction.

According to this apparatus, the filtrate adhering to the upper part of the casing and the bottom of the basket is washed away by the cleaning liquid, the amount of adhering to the upper part of the casing and the bottom of the basket is reduced, and the dry matter in the basket and to the cake outlet is dried. Fall is reduced. Therefore, even when the crystalline organic compound is separated by using the present apparatus, the dry solid matter and the deteriorated matter are less likely to be mixed into the crystal.

Water is usually used as the washing liquid used in this apparatus, but when it is used for crystal separation in the crystallization purification process of crystalline organic compounds such as terephthalic acid, hydroquinone, resorcin, etc., it is preferable to use an inorganic material for crystallization or An organic solvent is used. Examples of the cleaning and purification include a spray provided with a certain range in the circumferential direction at a constant interval, a cleaning pipe provided in a ring shape along the upper peripheral wall of the casing, and the like. The washing tube of is preferable. This is because the piping device becomes simple.

Another centrifuge is characterized in that the casing inner wall is provided with a filtrate discharge port which is opened in the circumferential direction, and preferably is opened inward from the casing inner wall.
In the case where the opening of the discharge port is provided on the inner wall of the casing,
If the filtrate that flows down the inner wall of the casing is discharged through the discharge port and the opening projects inward from the inner wall of the casing, most of the filtrate that flows between the basket and the casing is discharged through this discharge port. As a result, the adherence of the dry matter of the filtrate to the bottom of the casing is reduced.

In this apparatus, the opening of the discharge port for discharging the filtrate has a large inward projection amount in order to maximize the discharge amount of the filtrate discharged therethrough. It is desirable to place it as low as possible in the basket, preferably below the basket. Still another centrifuge is characterized in that fins are provided at appropriate intervals on the peripheral surface of the bottom of the basket facing the casing outlet so that the rotation of the basket causes a gas flow outward in the radial direction.

According to this apparatus, a gas flow is generated from the outside of the discharge port to the outside, so that the filtrate does not flow into the discharge port due to the gas flow.

[0012]

EXAMPLE The centrifuge shown in FIG. 2 is different from the centrifuge shown in FIG. 1 in that the cleaning liquid supply pipe 11 is connected to the peripheral edge of the ceiling of the casing 1 and the spray angle is changed as shown in FIG. The two rows of outlets 12 are arranged alternately, that is, the ring-shaped upper cleaning pipe 13 formed in a zigzag shape is arranged, and the cleaning liquid supply pipe 14 is provided on the casing lower frame 1a below the bottom of the basket forming the discharge port 6. Connected,
In addition, as shown in FIG. 4, upper and lower cleaning pipes 1 are provided with ring-shaped lower cleaning pipes 16 in which upper and lower two rows of outlets 15 with different spraying angles are staggered, that is, in a zigzag shape.
The cleaning liquid is sprayed onto the upper part of the casing and the upper part of the basket from No. 3, and the filtrate adhering to these is cleaned to prevent the dried filtrate from peeling off and being blown into the basket. Spraying on the basket bottom 2a forming a passage for sending the cleaning liquid to the discharge port 6, the front droop 2b hanging from the basket bottom, and the scattering prevention plate 17,
The filtrate adhering to these is washed to prevent the dried filtrate from being blown into the discharge port 6.

Further, at the lower part of the casing, there is provided a drain port 18 which projects in a ring shape on the inner circumference of the casing, is inclined upward so as to prevent the filtrate from adhering, and is opened upward. A drain pipe 21 connected to the drain pipe 19 is provided so that most of the filtrate that flows down the inner wall of the casing and passes between the basket 2 and the inner wall of the casing is drained from the drain port 18.
To reduce the adherence of the filtrate to the bottom of the casing.

Further, fins 22 are provided in the small diameter portion 2c of the basket 2 facing the discharge port 6 at regular intervals in the circumferential direction,
The rotation of the basket 2 causes a gas flow to be discharged through the discharge port 6 and the passage so that the filtrate does not flow into the discharge port 6.

[0015]

The present invention is configured as described above and has the following effects. According to the centrifuge of claim 1, since the filtrate adhering to the upper part of the casing and / or the bottom part of the basket is washed with the washing liquid, the dried product of the filtrate and the deteriorated product deteriorated due to the aging change in the basket and / or The cake is less likely to enter the discharge port, and the deterioration and fluctuation of the product quality can be reduced.

When an inorganic or organic solvent is used as the cleaning liquid as in the centrifuge according to the second aspect, the filtrate adhering to the upper part of the casing and / or the bottom part of the basket can be dissolved and cleaned thoroughly. When a ring-shaped cleaning pipe is used as the cleaning device as in the centrifuge according to the third aspect, the piping device is simple and the configuration is simple.

According to the centrifuge of the fourth aspect, the filtrate flowing down the inner wall of the casing is discharged, the adherence of the filtrate to the bottom of the casing is reduced, and the dried product of the filtrate is discharged to the cake outlet. It is possible to reduce intrusion. As in the centrifuge according to claim 5, if the discharge port is provided so as to project inward of the inner wall of the casing, most of the filtrate passing between the inner wall of the casing and the basket can be discharged, and therefore the bottom of the casing can be discharged. The amount of the filtrate attached to the cake is further reduced, and the amount of the dried solid matter of the filtrate to the cake can be reduced.

If the inclined portion is provided as in the discharge port according to the sixth aspect, the filtrate can be discharged smoothly without delay. According to the centrifuge of claim 7,
A gas flow from the outside of the cake outlet toward the outside is generated, and as a result, the inflow of the filtrate into the outlet due to the gas flow can be prevented.

According to the centrifuge described in claim 8, the effects of the centrifuge described in claims 1, 4 and 7 can be obtained together. According to the method of claim 9, it is possible to obtain a crystalline organic compound having a small amount of mixed dry matter and deteriorated matter.

[0020]

[Brief description of drawings]

[0021]

FIG. 1 is a schematic view of a conventional centrifuge.

[0022]

FIG. 2 is a schematic diagram of a centrifuge according to the present invention.

[0023]

FIG. 3 is an enlarged cross-sectional view of a main part of the centrifuge shown in FIG.

[0024]

4 is an enlarged cross-sectional view of another main part of the centrifuge shown in FIG.

[0025]

[Explanation of symbols]

 1 ... Casing 2 ... Basket 3 ... Raw material supply port 5 ... Cake layer 6 ... Discharge port 7 ... Drainage port 13 ... Upper cleaning pipe 16 ... Lower cleaning pipe 18 ... Discharge port 22 ... fin

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[Procedure amendment]

[Submission date] January 12, 1995

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

[Figure 3]

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 4

[Correction method] Change

[Correction content]

[Figure 4]

Claims (9)

[Claims] 1. A casing, a basket arranged in the casing and driven to rotate by a motor, a raw material supply port for supplying slurry into the basket, and a cake layer which opens below the bottom of the basket and is deposited on the inner wall of the basket. In a centrifuge having a discharge port for peeling and discharging, and a discharge port for filtrate discharged from a basket, the casing upper part and the basket upper part and the basket bottom part and the basket bottom part and the casing upper part and the basket upper part A centrifuge characterized in that a washing device for spraying either one or the other of the bottoms is provided. 2. The centrifuge according to claim 1, wherein an inorganic or organic solvent is used as a washing liquid when used for crystal separation in a crystallization purification process of a crystalline organic compound. 3. The centrifuge according to claim 1, wherein the cleaning device is a ring-shaped cleaning tube. 4. A casing, a basket arranged inside the casing and driven to rotate by a motor, a raw material supply port for supplying slurry into the basket, a cake layer which opens below the bottom of the basket and is deposited on the inner wall of the basket. A centrifuge having a discharge outlet for peeling and discharging and a discharge outlet for filtrate discharged from a basket, characterized in that a filtrate outlet opening in the same direction is provided on the inner wall of the casing. Separator. 5. The centrifuge according to claim 4, wherein the discharge port projects inward from the inner wall of the casing, and the opening faces upward. 6. The centrifuge according to claim 5, wherein the discharge port protruding from the inner wall of the casing is formed so as to reach the opening through the inclined portion. 7. A casing, a basket arranged in the casing and driven to rotate by a motor, a raw material supply port for supplying slurry into the basket, and a cake layer which opens below the bottom of the basket and is deposited on the inner wall of the basket. A centrifuge having a discharge port for peeling and discharging, and a discharge port for filtrate discharged from a basket, characterized in that fins are provided at appropriate intervals on a peripheral surface of a lower portion of the basket facing the discharge port. centrifuge. 8. The centrifuge according to claim 1, wherein the inner wall of the casing is provided with an outlet for the filtrate that opens in the same direction, and fins are provided at appropriate intervals on the peripheral surface of the lower portion of the basket facing the outlet. 9. A method for separating a crystalline organic compound from a solvent using a centrifuge having the structure according to claim 1.