JPH0426906B2 - - Google Patents

Description

Detailed Description of the Invention The present invention divides a particle suspension into three components: a component containing many coarse particles with a high sedimentation rate, a component containing many fine particles with a low sedimentation rate, and an intermediate flow diameter component. The present invention relates to a hydrocyclone device for

2. Description of the Related Art Hydrocyclone devices have been widely used as devices for classifying particle suspensions, removing coarse particles, and the like. To explain the mechanism and function of a conventional liquid cyclone device in the Bauer Sentry Cleaner, which is used as a liquid cyclone device for pulp suspension treatment, the pulp suspension that is tangentially injected from the inlet is placed close to the cyclone wall. Along with the primary vortex in the outer layer, it descends inside the cyclone in a rotating spiral motion, and at this time coarse particles unsuitable for papermaking (such as sand grains and metal pieces mixed in with the raw material wood chips) have a higher sedimentation speed than the fiber components. )
is collected near the wall surface by centrifugal force and discharged along with a downward flow from a downstream discharge pipe attached to the lower end of the lower conical swirl chamber. On the other hand, good fiber components rise in a rotating spiral motion due to the inner layer secondary vortex near the central axis of the cyclone and are taken out from the overflow riser pipe.

However, in the above hydrocyclone device, in the lower part of the conical vortex chamber, that is, near the descending outlet, there is a downward flow due to the outer layer primary vortex near the wall surface, an upward flow due to the inner layer secondary vortex, and furthermore, there is a downward flow due to the inner layer secondary vortex near the wall surface. The downward flow that exists in contact with the air core generated at the central axis (center downward flow) intersects to form a very complex flow, and the coarse particles unsuitable for papermaking collected near the wall and the inner layer secondary There is a great risk of remixing of the good fiber components in the vortex. Further, fine fibers, short fibers, etc. contained in large quantities in the central downward flow are also discharged from the downward outlet together with coarse particles. This remixing reduces the removal efficiency of coarse particles.

In fact, in the normal pulp suspension treatment using the Bauer Sentry Cleaner, coarse particles are also included in the good fiber components taken out from the overflow riser pipe, and the discharge from the downstream outlet pipe also contains good fibers. It also contains many fine fibers. Therefore, in order to improve coarse particle removal efficiency and recover good fibers,
In reality, multi-stage processing is performed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cyclone device that improves the above-mentioned drawbacks found in conventional hydrocyclone devices.

A structural feature of the present invention is that a main body is provided with a supply pipe for introducing a particle suspension in a tangential direction into a cylindrical part at the upper part of the main body of the hydrocyclone device, and a main body for taking out a component containing an intermediate particle size component from inside the cylindrical part. has an overflow riser pipe arranged coaxially with the central axis of the cylindrical part, a truncated cone-shaped vortex chamber is provided at the lower part following the cylindrical part, and a discharge pipe and the above-mentioned vortex flow chamber are provided at the lower end thereof to take out components containing coarse particles in the tangential direction. This is a three-component split type hydrocyclone device comprising a central downward flow discharge pipe disposed coaxially with the central axis of the main body inside the chamber.

The present invention will be described in detail below with reference to the accompanying drawings illustrating the present invention using an example in which a pulp suspension is used as the particle suspension.

The accompanying drawing is an axial sectional view conceptually illustrating one form of a cyclone device according to the present invention.

In the figure, 1 is a supply pipe that introduces the pulp suspension into the upper part of the cyclone apparatus main body, 2 is a cylindrical part of the cyclone apparatus main body, and 3 is a truncated cone-shaped vortex flow provided at the opposite lower part following the cylindrical part. 4 indicates an overflow riser pipe, 5 indicates a coarse particle component discharge pipe, 6 indicates a central downward flow discharge pipe, and 7 indicates an air core formed in the main body at its central axis.

In the figure, the pulp suspension introduced from 1 is caused by the centrifugal force of the outer layer primary vortex at the lower end of the vortex chamber 3 of the cyclone device main body to remove coarse particles such as sand grains, metal pieces, and bundles in the pulp suspension. fibers, dust,
Components unsuitable for paper manufacturing, such as large conduit elements, are collected near the wall of the vortex chamber and are discharged from the discharge pipe 5 attached tangentially from the wall surface at the lower end of the lower vortex chamber of the cyclone device, without mixing with the inner secondary vortex. taken out. In addition, the central downward flow containing many fine fibers and short fibers, which was discharged together with coarse particle components in conventional hydrocyclone devices, is removed by the central downward flow discharge pipe 6 disposed coaxially with the central axis of the main body inside the vortex chamber. It is extracted separately from coarse particle components. It is preferable that the upper end of the central downward flow discharge pipe 6 be installed above the coarse particle component discharge pipe 5 provided in the tangential direction, also from the viewpoint of preventing mutual mixing of the two components. In addition, components containing good fibers are taken out from the overflow riser pipe 4 while rotating in a spiral motion due to the inner layer secondary vortex near the central axis of the cyclone body.

As mentioned above, the present invention was made based on the results of many years of research into elucidating the flow state of pulp suspension inside a cyclone device. Therefore, the effect in terms of effective utilization of pulp suspension is extremely large. In addition, the cyclone apparatus according to the present invention has the advantage that the number of processing stages can be reduced in actual operation compared to the conventional multi-stage processing method.

The liquid cyclone device according to the present invention has been described above by taking the treatment of pulp suspension as an example. However, according to the present invention, by dividing the downward flow into two and preventing the mixing of coarse particles and fine particles, the liquid cyclone device according to the present invention is Since it is possible to perform sharper classification than the apparatus, the hydrocyclone apparatus according to the present invention can be expected to be used in a wide variety of fields, not only for treating pulp suspensions but also for various particle suspensions.

[Brief explanation of drawings]

The figure is an axial sectional view conceptually showing a hydrocyclone device according to the present invention. In the figure, arrows indicate the axial flow component of the fluid within the cyclone. In the figure, 1...particle suspension supply pipe, 2...upper cylindrical part of the cyclone device, 3...truncated conical swirl chamber, 4...
...Overflow rising pipe, 5... Coarse particle discharge pipe, 6... Center downward flow discharge pipe, 7... Air core.

Claims (1)

[Claims] 1. A liquid cyclone device that divides a particle suspension into three components: a component containing many coarse particles with a high sedimentation rate, a component containing many fine particles with a low sedimentation rate, and an intermediate particle size component. A supply pipe is provided for introducing the particle suspension tangentially into the cylindrical part at the top of the main body, and an overflow riser pipe is arranged coaxially with the central axis of the main body for taking out the intermediate particle size component inside the cylindrical part. A truncated cone-shaped vortex chamber is provided at the bottom of the main body following the cylindrical portion, and at its lower end there is a discharge pipe for taking out coarse particle components in the tangential direction, and a discharge pipe is formed inside the vortex chamber to remove fine particles. A three-component split type liquid cyclone device comprising a center downward flow discharge pipe coaxially arranged with the center axis of a main body for discharging a center downward flow containing a large amount. 2. The hydrocyclone device according to claim 1, wherein the upper end of the central downward flow discharge pipe is disposed above the upper end of the discharge pipe for taking out coarse particle components in the tangential direction.