JP7522475B2 - Centrifuge and method for washing solids using the centrifuge - Google Patents

Description

Applicable under Article 30, Paragraph 2 of the Patent Act. On sale from March 15, 2022.

Applicable under Article 30, Paragraph 2 of the Patent Act. On sale from March 15, 2022.

The present invention relates to a centrifuge that supplies a raw liquid into a rotating basket and separates the raw liquid into a liquid portion and a solid portion (cake) using the centrifugal force generated by the rotation of the basket, and a method for washing solid portions using this centrifuge.

Conventionally, a centrifuge has been used for the purpose of separating various raw liquids into liquid and solid components.
The centrifuge comprises a basket having an opening at least on one end side in the axial direction, a rotary drive device which rotates the basket, and a liquid supply device which supplies raw liquid into the basket through the opening of the basket, and separates the raw liquid supplied into the basket into a liquid fraction and a solid fraction by utilizing the centrifugal force generated by the rotation of the basket.

Known types of centrifuges include centrifugal filtration centrifuges that use a basket with through holes in the peripheral wall and discharge the liquid through a filter placed on the inner periphery of the peripheral wall of the basket and through the through holes in the peripheral wall (see, for example, Patent Document 1), and centrifugal sedimentation centrifuges that use a basket without through holes in the peripheral wall and discharge the liquid separated from the raw liquid using a skimming device (see, for example, Patent Document 2).

After the raw solution is separated into a liquid portion and a solid portion, there is a need to further wash away impurities contained in the solid portion using a washing liquid.
In centrifugal filtration centrifuges, this need can be met by separating the stock solution into liquid and solids, and then washing the solids by pouring a washing liquid over them while rotating the basket. However, there is a problem that, for example, when the solids contained in the stock solution are fine particles, they cannot be captured and pass through the filter, or they clog the filter, making it impossible to use a centrifugal filtration centrifuge.

JP 2005-34756 A JP 2003-93811 A

The present invention was made in consideration of the above-mentioned circumstances, and aims to provide a centrifuge that makes it possible to wash impurities contained in solid matter consisting of fine particles using a washing liquid, and a method for washing solid matter using this centrifuge.

To achieve the above object, the centrifuge of the present invention is a centrifugal sedimentation type centrifuge equipped with a bottomless, non-perforated basket with an opening on the top surface, a rotary drive device for rotating the basket, a liquid supply device for supplying the raw liquid into the basket, a skimming device for discharging the liquid separated from the raw liquid, and a scraping device for scraping off the solid matter that has been separated from the raw liquid and adhered to the periphery of the basket as a cake, and is characterized by being equipped with a cleaning liquid supply device for supplying cleaning liquid into the basket, and an agitation device for agitating the solid matter scraped off by the scraping device and the cleaning liquid supplied from the cleaning liquid supply device.

In this case, the agitator may include a movement mechanism for selectively positioning the agitator at a standby position above the center of the basket and at a mixing position below the outer periphery.

In order to achieve the same object, a method for washing solids using a centrifuge according to the present invention is characterized in that it uses the above-mentioned centrifuge and comprises the following steps (1) to (7):
(1) A step of supplying the raw liquid into the basket by a liquid supply device.
(2) A step of separating the raw liquid into a liquid fraction and a solid fraction by rotating the basket using a rotary drive device.
(3) A process of discharging the liquid separated from the raw liquid by the skimming device from within the basket.
(4) A process of scraping off the solid matter that has been separated from the stock solution and adheres to the periphery of the basket as a cake using a scraping device.
(5) A step of supplying a cleaning liquid into the basket by a cleaning liquid supplying device.
(6) A process in which the scraped solids are stirred with the cleaning solution using a stirring device, thereby washing away impurities contained in the solids with the cleaning solution.
(7) A process of discharging the mixture of solids and cleaning liquid from the basket using a skimming device.

The centrifuge of the present invention and the method for washing solids using this centrifuge make it possible to wash away impurities contained in the solids, which are made up of fine particles, using a washing liquid.

FIG. 1 is a plan view showing an embodiment of a centrifuge according to the present invention. FIG. 2 is a front cross-sectional view of the centrifuge. 3A and 3B show a liquid supply device and a cleaning liquid supply device of the centrifuge, in which FIG. 3A and 3B show a skimming device of the centrifugal separator, in which FIG. 3A and 3B show a scraping device of the centrifugal separator, in which FIG. 3A and 3B show a stirring device of the centrifugal separator, in which FIG. FIG. 2 is a process explanatory diagram showing one embodiment of a method for washing solids using a centrifuge of the present invention.

The following describes an embodiment of the centrifuge of the present invention and a method for washing solids using this centrifuge, with reference to the drawings.

1 to 6 show an embodiment of a centrifuge according to the present invention.
This centrifuge is a centrifugal sedimentation type centrifuge and includes a bottomed, non-perforated basket 2 with an opening on its top surface that is rotatably arranged within a main body 1, a rotary drive device 3 that drives the basket 2 to rotate, a liquid supply device 4 that supplies raw liquid R into the basket 2, a skimming device 5 that discharges liquid L separated from the raw liquid R, a scraping device 6 that scrapes off solids S that have been separated from the raw liquid R and adhered to the peripheral surface of the basket 2 as a cake, a cleaning liquid supply device 7 that supplies cleaning liquid W into the basket 2, and an agitation device 8 that agitates the solids S scraped off by the scraping device 6 and the cleaning liquid W supplied from the cleaning liquid supply device 7.

In this case, the basket 2 is rotated by the rotation drive device 3, but the rotation speed is changeable, at least allowing high and low speed rotation.

A liquid supply device 4 supplies raw liquid R into the basket 2, and a cleaning liquid supply device 7 supplies cleaning liquid W.
As shown in FIG. 3, the raw liquid R and the cleaning liquid W are supplied into the basket 2 through liquid supply pipes 11 and 12 formed on the main body 1.
In this case, the raw liquid R and the cleaning liquid W can be supplied from one or both of the liquid supply pipes 11, 12, or the raw liquid R can be supplied from one of the liquid supply pipes 11, 12 and the cleaning liquid W can be supplied from the other.

As shown in Figure 4, the skimming device 5 supplies the raw liquid R into the basket 2 using the liquid supply device 4, and rotates the basket 2 using the rotation drive device 3 to separate the raw liquid R into a liquid fraction L and a solid fraction S, and then sucks up and discharges the liquid fraction L separated from the raw liquid R from the basket 2.
The skimming device 5 is provided with a moving mechanism 52 that selectively positions the nozzle portion 51 of the skimming device 5 between a standby position above the center side within the basket 2 and a suction position on the outer periphery side (lower).

As shown in FIG. 5, the scraping device 6 sucks up and discharges the liquid L separated from the raw liquid R from within the basket 2, and then scrapes off the solid S that has been separated from the raw liquid R and adheres to the peripheral surface of the basket 2 as a cake.
The scraping device 6 is provided with a moving mechanism 62 for selectively positioning a scraping blade 61 of the scraping device 6 between a standby position above the center of the basket 2 and a scraping position on the outer periphery.

As shown in FIG. 6 , the agitation device 8 agitates the solids S scraped off by the scraping device 6 and the cleaning liquid W supplied from the cleaning liquid supply device 7, thereby cleaning impurities contained in the solids S with the cleaning liquid W.
The agitator 8 is provided with a moving mechanism 82 for selectively positioning an agitating blade 81 of the agitator 8 between a standby position above the center of the basket 2 and an agitating position below the outer periphery.

Next, a method for washing solids using the above-mentioned centrifuge will be described.
This method for washing solids using a centrifuge includes the following steps (1) to (7), as shown in FIG.
(1) A step of supplying the raw liquid R into the basket 2 by the liquid supply device 4.
(2) A step of separating the raw liquid R into a liquid fraction L and a solid fraction S by rotating the basket 2 using the rotary drive device 3.
(3) A process of discharging the liquid L separated from the raw liquid R by the skimming device 5 from inside the basket 2. In this case, the position of the nozzle portion 51 of the skimming device 5 can be positioned at any position on the outer periphery side inside the basket 2 (in this embodiment, the lower position).
(4) A process of scraping off the solids S that have been separated from the raw liquid R and adhered to the peripheral surface of the basket 2 as a cake by the scraping device 6.
(5) A step of supplying the cleaning liquid W into the basket 2 by the cleaning liquid supply device 7.
(6) A process of washing impurities contained in the solids S with the washing liquid W by stirring the scraped solids S with the stirring device 8.
(7) A process of discharging the mixture M of solids S and cleaning liquid W from the basket 2 using a skimming device 5.

In this case, the rotation speed of the basket 2 by the rotation drive device 3 in steps (1) to (7) above shall be as shown in Table 1.

Here, the washing of the solid content S is not limited to one time, but can be repeated a number of times.
Specifically, after the washing step (6), steps (2) to (6) can be repeated.

In addition, in this embodiment, by carrying out the steps (1) to (7) above, the operations from supplying the cleaning liquid to cleaning impurities contained in the solids consisting of fine particles can be performed fully automatically without manual intervention, from the supplying to the discharging. However, the mixture M of the solids S and the cleaning liquid W discharged from the basket 2 can be separated into the solids S and the cleaning liquid W by sedimentation or by using another centrifugal sedimentation type centrifuge, for example, a centrifugal sedimentation type centrifuge equipped with a bottomless, non-porous basket with an opening on the top surface, as necessary.

Of the above steps (1) to (7), step (7) can be omitted, and the scraped solids S and cleaning solution W can be stirred by the stirring device 8 to wash away impurities contained in the solids S using the cleaning solution W, after which steps (2) to (4) can be carried out and the scraped solids S can be removed from the basket 2 by the scraping device 6.

This centrifuge and the method for washing solids using this centrifuge make it possible to wash away solids consisting of fine particles, such as impurities contained in magnetic materials, using a washing liquid.

The centrifuge of the present invention and the method for washing solids using this centrifuge have been described above based on examples, but the present invention is not limited to the configurations described in the above examples, and the configurations can be changed as appropriate within the scope of the spirit of the invention.

The centrifuge of the present invention and the method for washing solids using this centrifuge can be suitably used for washing solids consisting of fine particles.

REFERENCE SIGNS LIST 1 Body 11 Liquid supply pipe 12 Liquid supply pipe 2 Basket 3 Rotation drive device 4 Liquid supply device 5 Skimming device 6 Scraping device 7 Cleaning liquid supply device 8 Mixing device R Stock solution L Liquid content S Solid content W Cleaning liquid M Mixed liquid

Claims (3)

A centrifugal sedimentation type centrifuge comprising a bottomed, non-perforated basket having an opening on its upper surface, a rotary drive device for rotating the basket, a liquid supply device for supplying raw liquid into the basket, a skimming device for discharging liquid separated from the raw liquid, and a scraping device for scraping off solid matter that has been separated from the raw liquid and adheres to the circumferential surface of the basket as a cake, characterized in that the centrifuge further comprises a cleaning liquid supply device for supplying cleaning liquid into the basket, and a stirring device having a moving mechanism for selectively positioning the stirring device between a standby position above the center of the basket and a stirring position below the outer periphery in order to mix the solid matter scraped off by the scraping device and the cleaning liquid supplied from the cleaning liquid supply device. A method for washing solids using a centrifuge, comprising the following steps (1) to (6), using the centrifuge according to claim 1:
(1) A step of supplying the raw liquid into the basket by a liquid supply device.
(2) A step of separating the raw liquid into a liquid fraction and a solid fraction by rotating the basket using a rotary drive device.
(3) A process of discharging the liquid separated from the raw liquid by the skimming device from within the basket.
(4) A process of scraping off the solid matter that has been separated from the stock solution and adheres to the periphery of the basket as a cake using a scraping device.
(5) A step of supplying a cleaning liquid into the basket by a cleaning liquid supplying device.
(6) A process in which the stirring device is moved by the moving mechanism from a standby position above the center of the basket to a stirring position below the outer periphery, and the scraped off solids are stirred with the cleaning liquid, thereby washing away impurities contained in the solids with the cleaning liquid. The method for washing solids using a centrifuge according to claim 2 , further comprising the following step (7) in addition to the steps (1) to (6).
(7) A process of discharging the mixture of solids and cleaning liquid from the basket using a skimming device.

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