JP2001276664A - Centrifugal separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a centrifugal separator which prevents the clogging of the inside of a casing and a solid ejection port with solids and allows continuous operation. SOLUTION: This centrifugal separator separates the solids from a liquid by supplying a slurry into a rotary cylinder 2 installed horizontally in a casing 1 and rotating around an axial center A and allowing the solids 17 in the slurry by centrifugal force on the wall surface of a rotary cylinder 2, scrapes off the solid 17 by a screw conveyor 3 disposed within the rotary cylinder 2, discharges the solids from a solid discharge port 11 at the terminal of the rotary cylinder 2 and ejects the solids from the solid ejection port 14 disposed at the bottom of the casing 1. A gas blow-off pipe 16 is connected to the casing 1 and the solids 17 discharged from the solid discharge port 11 are forcibly discharged from the solid ejection port 14 by the gas blown off into the casing 1 from the gas blow-off pipe 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a centrifugal separator for separating solids from a slurry and continuously discharging the solids.

[Prior art]

[0002] Centrifugal separators are widely used in the case of sedimentation and separation of solids from slurries, for example, for dewatering washed polymer particles from a washing liquid or for separating and dewatering activated sludge. As such a centrifuge,
For example, the slurry is supplied into a rotating cylinder that rotates about an axis, and acceleration is applied to the slurry by centrifugal force that is several thousand times the gravitational force to cause solids in the slurry to settle on the inner surface of the rotating cylinder. A centrifugal separator of a type in which the solid is scraped off by a screw conveyor accommodated coaxially with the rotary cylinder and continuously discharged from a solid discharge port at the end of the rotary cylinder is well known. In this centrifugal separator, the solid discharged from the solid discharge port is discharged from the solid discharge outlet at the bottom of the casing containing the rotary cylinder and sent to the next step such as a drying step. In addition, this type of centrifugal separator is sometimes called a decanter centrifuge, and as commercially available devices, Sharpless Super Decanter (trade name, manufactured by Tomoe Industries Co., Ltd.), decanter centrifuge (trade name,
(Ishikawajima General-Purpose Machine Service Co., Ltd.).

[0003]

Depending on the type of solids to be separated, the solids continuously discharged from the rotary cylinder stay in the casing, especially at or near the solids outlet, and finally the solids outlet. Has been clogged, making it impossible to carry out the solid matter to the next step. Such a problem is particularly remarkable in a centrifugal separator in which a rotary cylinder is installed in a horizontal direction. When the solid is polymer particles or the like which are likely to aggregate, the solid material outlet is clogged in a short time. Was.

[0004] Therefore, every time clogging occurs, it is necessary to stop the operation of the centrifugal separator and remove the solid matter accumulated in the casing, resulting in poor production efficiency and work efficiency. Accordingly, an object of the present invention is to provide a centrifugal separator that prevents continuous operation in a casing by preventing the inside of a casing and a solid material outlet from being clogged with a solid material.

[0005]

A centrifugal separator according to the present invention for solving the above-mentioned problems supplies a slurry to a rotating cylinder which is installed laterally in a casing and rotates around an axis, and is supplied with a centrifugal force. The solids in the slurry are settled on the inner surface of the rotary cylinder to perform solid-liquid separation, and the solids are scraped off by a screw conveyor provided in the rotary cylinder, discharged from the solids discharge port at the end of the rotary cylinder, and the casing is removed. It is carried out from a solid material outlet provided at the bottom, and a gas blowing pipe is connected to the casing, and the gas discharged from the solid material discharging port by the gas blown into the casing from the gas blowing pipe. The material is forcibly discharged from the solid material outlet.

With this configuration, the centrifugal separator of the present invention reliably discharges even solids, such as polymer particles, which are easily clogged from the solids discharge port by the gas blown into the casing from the gas blowing pipe. This prevents the solids from staying in the casing or at the solids discharge port to cause clogging.

In the present invention, the gas blowing pipe is connected above the solid discharge port, and the gas blowing pipe is inclined with respect to the casing so that the gas blowing direction into the casing is the same as the rotation direction of the rotary cylinder. It is preferable that they are connected to each other. Thereby, the solid discharged from the solid discharge port can be more reliably discharged from the solid discharge port.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a horizontal centrifugal separator according to this embodiment, in which a rotary cylinder 2 is installed horizontally in a casing 1, and a screw conveyor 3 coaxial with the rotary cylinder 2 is accommodated in the rotary cylinder 2. . Hollow rotary shafts 4 and 5 are integrally formed at both ends of the rotary cylinder 2, and a pulley 6 is attached to one rotary shaft 4,
An electric motor (not shown) is connected to the pulley 6 via a drive belt.
Are connected to rotate the rotary cylinder 2 about the axis A. The other rotating shaft 5 is connected to a gear box 7 (reducer) as an input shaft.

The screw conveyor 3 in the rotary cylinder 2
Has one end rotatably slidably connected to the rotating shaft 4 and the other end connected to the output shaft 19 which is coaxial with the rotating shaft 5 and is inserted through the rotating shaft 5 from the gear box 7, and has the same direction as the rotating cylinder 2. And at a rotation speed lower than that of the rotary cylinder 2. Generally, the rotation speed of the rotary cylinder 2 is about 1500 to 5000
The rotational speed of the screw conveyor 3 is preferably about 30 to 60 rpm lower than that of the screw conveyor.

In the hollow portion 8 of the screw conveyor 3,
The feed tube 9 inserted through the rotation shaft 4 is inserted,
The slurry is supplied from the feed tube 9 into the hollow portion 8. A slurry discharge port 10 is provided on the peripheral wall of the screw conveyor 3. The rotary cylinder 2 has a slope 12 having one end inclined in a substantially conical shape.
1 is provided. A dam plate 13 (overflow weir) is provided at the other end of the rotary cylinder 2. This dam plate 13
The height from the peripheral wall of the rotary cylinder 2 is set to be lower than the solid discharge port 11.

The casing 1 accommodates the rotary cylinder 2 and has a solid substance discharge port 14 and a clarified liquid discharge port 15 at the lower part.
Is provided. The solids outlet 14 and the clarified liquid outlet 15 are located substantially below the solids outlet 11 and the dam plate 13 of the rotary cylinder 2, respectively. A gas blowing pipe 16 is connected to an upper portion of the casing 1.

The gas blowing pipe 16 is formed by the gas blown into the casing 1 from the gas blowing pipe 16.
Since the solid matter discharged from the solid matter discharge port 11 is forcibly discharged from the solid matter discharge port 14, it is installed above the solid matter discharge port 11 and the solid matter discharge port 14. Preferably, as shown in FIG. 2, the gas blowing pipe 16 has a direction in which gas is blown into the casing 1 (indicated by a solid arrow) and a direction in which the rotating cylinder 2 rotates (indicated by a dashed arrow). It is preferable that the solid material is connected to the casing 1 at an angle so that the solid material can be smoothly discharged from the solid material outlet 14. As the gas blown out from the gas blowout pipe 16, usually,
Air is used, but depending on the type of solids to be separated,
For example, various gases such as nitrogen gas and oxygen gas can be used.

Next, the operation of the centrifugal separator according to this embodiment will be described. Rotating cylinder 2 and screw conveyor 3
When the slurry is supplied from the feed tube 9 into the hollow portion 8 of the screw conveyor 3 while rotating each at a predetermined rotation speed, the slurry is discharged into the rotary cylinder 2 from the slurry discharge port 10 of the screw conveyor 3 by centrifugal force. Is done. In the rotating cylinder 2 rotating at high speed, the solids 17 in the slurry settle on the inner wall surface of the rotating cylinder 2 and are separated from the clarified liquid 18 from which the solids 17 have been removed.

Solids 17 deposited on the inner wall surface of the rotary cylinder 2
Are scraped off by the blades 31 of the screw conveyor 3 rotating in the same direction as the rotating cylinder 2 at a lower rotation speed than the rotating cylinder 2 and sequentially sent to the rotating shaft 4 side of the rotating cylinder 2.
Is discharged from a solid discharge port 11 formed in the casing 1 and discharged from a solid discharge port 14 of the casing 1. On the other hand, clarified liquid 1
Numeral 8 denotes a dam plate 13 set at a lower level than the solid material discharge port 11, and a constant liquid level is maintained. The clarified liquid exceeding the liquid level overflows the dam plate 13 and the clarified liquid discharge port It is discharged from 15.

In the process of continuously separating the solid 17 and the clarified liquid 18 in this manner, the solid 17 stays on the inner surface of the casing 1 and the solid outlet 14, and finally the solid outlet 17. However, in this embodiment, the gas is blown out from the gas blow-out pipe 16 in the upper part of the casing 1 in the same direction as the rotation direction of the rotary cylinder 2. 14 solids 1
7 is prevented from accumulating. Gas blowing pipe 16
The flow rate of the gas blown out is not particularly limited, but is usually 1 m ³ / min or more, preferably 5 to 10 m ³ / min.
³ / min is good. The temperature of the gas is not unique depending on the type of the solid 17, but is usually 30 °.
C. or higher, preferably 100 to 200C.

As described above, in this embodiment, since the solids 17 are prevented from adhering and staying on the inner surface of the casing 1 and the solids outlet 14, the clogging at the solids outlet 14 and the like is eliminated, and the centrifugation is performed. Continuous operation of the separation device becomes possible, and production efficiency and work efficiency are improved.

The gas blowing pipe 16 may be installed at an angle as described above, or may be vertically connected to the casing 1, and various changes can be made depending on the use conditions and the like. Further, as the slurry to which the present invention can be applied, a slurry containing the polymer particles as described above, and specific examples include an AS resin, an ABS resin, a vinyl chloride resin, a ketone resin, a fluororesin, a polyacetal, a polyamide, a polyamideimide, and a polyimidide. Arylate, polyetherimide, polyetheretherketone, polyethylene, polyethylene terephthalate, polycarbonate, polystyrene,
Slurries containing polysulfone, polyethersulfone, polypropylene, methacrylic resin, liquid crystal polymer, epoxy resin, vinyl ester resin, phenolic resin, unsaturated polyester, furan resin, polyimide, polyurethane, melamine resin, urea resin and the like can be mentioned. In addition, clays, metals, metal oxides, metal hydroxides, metal nitrides, metal carbides, intermetallic compounds, slurries containing glass, etc., water slurries such as activated sludge, and further high viscosity slurries, etc. There is no restriction.

[0018]

According to the centrifugal separator of the present invention, the solids are forcibly discharged from the solids discharge port by the gas blown into the casing from the gas blowing pipe. Prevention of clogging due to stagnation of solids is prevented. As a result, continuous operation of the centrifugal separator becomes possible, which has the effect of improving production efficiency and work efficiency.

[Brief description of the drawings]

FIG. 1 is a partially cutaway sectional view showing an outline of a centrifugal separator according to an embodiment of the present invention.

FIG. 2 is a schematic side view of the centrifugal separator shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing 2 Rotating cylinder 3 Screw conveyor 9 Feed tube 10 Slurry discharge port 11 Solid discharge port 14 Solid discharge port 15 Refined liquid discharge port 16 Gas blowing pipe 17 Solid substance

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Eiji Hosoda 5-1 Sokai-cho, Niihama-shi, Ehime F-term in Sumitomo Chemical Co., Ltd. (Reference) 4D057 AA05 AA07 AA11 AB01 AC01 AC06 AD01 AE01 AF03 BA13 BA36 BC05 BC13 BC16 CA07 CB05 4D059 AA00 BE38

Claims (2)

[Claims] 1. A slurry is supplied into a rotating cylinder which is installed laterally in a casing and rotates about an axis, and solids in the slurry are settled on the inner surface of the rotating cylinder by centrifugal force.
While performing solid-liquid separation, centrifugal separation in which the solid is scraped off by a screw conveyor provided in the rotary cylinder, discharged from a solid discharge port at the end of the rotary cylinder, and discharged from a solid substance discharge port provided at the bottom of the casing. In the device, a gas blowing pipe is connected to the casing, and the solid discharged from the solid discharge port is forcibly discharged from the solid discharge port by gas blown into the casing from the gas blowing pipe. A centrifugal separator characterized in that: 2. The gas discharge pipe is connected to an upper portion of the solid material discharge port, and is inclined with respect to the casing so that the direction of gas discharge into the casing is the same as the rotation direction of the rotary cylinder. The centrifugal separator according to claim 1, which is connected.