JPS5889958A - Cyclone separator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for separating solid particles into light and heavy parts in a fluid containing both gas and liquid, and more particularly, the present invention relates to an apparatus for separating solid particles into light and heavy parts in a fluid containing both gas and liquid. This relates to the separation of

It is now well known to use vortex or cyclonic cleaners to separate cellulose fibrous sand, grids, bark particles and binding fibers in slurries of steaming/cleaning. Generally, such leaners are It contains an elongated chamber of either cylindrical or somewhat tapered circular cross-section. The pulp slurry to be cleaned is placed under pressure at one end of the chamber so as to create a high-velocity vortex flow along the length of the chamber. The introduced vortex flow is typically of sufficient velocity to form a centrally positioned, axially unidirectional gas core within the chamber.The end opposite the chamber entrance is tapered. The pulp slurry has a high density and forms four relatively small-diameter apex discharge ports for large particle rejects.
The screened fibers reverse their flow direction near the tapered end of the chamber and flow upwards to be drawn out through the large I diameter axial outlet of the chamber.

Generally, a cyclonic separation system includes several stages coupled in series, each stage connected in parallel and containing a common inlet and outlet chamber. From K, the second stage processes the objects that did not pass through the first stage, the eighth stage processes the objects that did not pass through the second stage, and the following stages sequentially process the objects that did not pass through the straight curved stage. It minimizes the amount of high-quality fiber that is wasted while concentrating impurities in one point. Such systems separate the initial, highly diluted pulp suspension into a usable papermaking fiber fraction (the less dense pass-through fraction) and concentrated larger, denser impurities (the reject fraction). used for. The increased flow of rejects from the cyclonic separation system allows for more complete removal of contaminants and impurities from the pulp suspension. However, increased flow of rejects results in increased power requirements for the system to process and convey increased volumes of material. Additionally, increasing reject flow increases the amount of quality fiber that is discarded from the system.

However, the smaller the diameter of the separator's retentate outlet, the more likely the separator will become clogged with impurities. Many attempts have been made to solve the problem of controlling fiber loss and blockage of the retentate outlet. In one attempt, water was applied under pressure to dilute the heavy rejects and wash out the fine papermaking fibers. Other attempts utilized special valve systems to control the flow of rejects through the four discharge ports. Some examples of this woodcutter's attempted solutions include U.S. Pat.
, No. 696,927 and No. 8.2? ? , No. 926. - Other attempts have utilized positioning grooves, twills and guide rods in the tapered portion of the cyclone chamber to control non-passage flow. Some examples of attempted solutions of this kind are U.S. Pat.
．． No. 158558, No. 4.156.485 and No. 4
, 224, 145.

These attempts have been at best only partially successful in solving the occlusion problem and reducing fiber loss.

Therefore, there remains a need for a cyclonic separator that is efficient, free from blockage problems, and minimizes the loss of quality papermaking fibers through the retentate outlet.

The present invention addresses such needs by providing a cyclonic separator in which the interior wall of the separator gradually changes from a circular cross-section to a non-circular cross-section retentate outlet. By changing the shape of the rejects outlet of the cyclone separator, the ratio of rejects, the concentration factor, and the feed pressure to the device can also be changed, while maintaining approximately the same cleaning efficiency without clogging problems. It turns out. The modified retentate outlet of the present invention can be incorporated or formed as an integral part of prior art cyclonic separators, or can be constructed as a replaceable tip. Furthermore, the invention has utility with either a single separation device or a group of such separation devices.

The modified retentate outlet of the present invention is also described in U.S. Patent No. 4.1.
It may also be used in conjunction with a reversible centrifugal cleaning device, such as the device described in No. 55,889. Finally, the present invention can also be used for special separation from gases.

By deforming the retentate outlet non-circularly, several operational advantages are achieved. These advantages include: Namely, 1. Significantly reduce the proportion of rejects, i.e., without clogging and greatly reduce the loss of good quality fibers from the cleaner, reducing the proportion of rejects by 100% compared to the feed stock. It decreases considerably.

8. The use of a square outlet provides greater consistency of the flow through compared to a standard circular outlet.

8. The concentration factor is low, ie, the ratio of retentate consistency to feed consistency is high when an oblong or rectangular outlet is used.

4. Works satisfactorily at lower feed pressures than standard circular exit polymerization.

5. Has the ability to handle larger volume feed streams.

6. A significantly larger outlet opening is available with less chance of blockage and yet maintains a similar retentate rate to prior art retentate outlets.

Additionally, a cyclonic separator paste using the present invention9
-Jung efficiency is hardly affected by non-circular retentate exits. It is therefore one object of the present invention to provide flexibility in the construction of such cyclonic separation systems in order to achieve one or more of the above-described operational advantages without sacrificing cleaning efficiency. It is an object of the present invention to provide a cyclonic separator that is efficient, free from blockage problems, and which minimizes the loss of quality papermaking fibers from non-passing dynamic outlets. This and other objects and advantages will become apparent from the following description, the accompanying drawings, and the claims.

Referring to FIG. 1, a typical cyclonic separator is shown. Of course, the invention is not limited to a single device including a reversible centrifugal cleaning device, but also includes arrangements in groups. The device has a cylindrical part 12
and a hollow cyclone member lO defining a separation chamber having a tapered portion 14 and a hollow apex conical portion 16 having an outlet aperture 17. The cylindrical portion and tapered portion of the cyclone member may be made of a polymeric resin material such as polypropylene, polystyrene, nylon, or the like. The apex tip 16 is preferably made of a wear-resistant ceramic material, but could also be made of the same material as the cyclone member and of integral construction therewith.

The cylindrical portion 11 of the cyclone element 10 has a tangential slot-like inlet 18 through which a fluid suspension of material such as stock enters the device. The cylindrical part l of the cyclone member lO! At the end of the cyclone element 10 there is provided a closure cover 80 which can be made of the same polymeric resin material as the rest of the cyclone element IO. Closed cover! The ends of 10 and cylindrical portion 12 may be threaded for sealingly securing each other.

The closure cover BOK is also provided with a centrally located vortex finder or puff flow nozzle tube 31 through which the suspension part flows.
is the cylindrical part l! The center of the body is sharpened inward.

Cyclone member IO includes an apical tip member 16, which is preferably made of a wear-resistant cast ceramic material. Tapered tip 16 forms an extension of tapered portion 14 and is initially adapted to receive an annular coupling nut 28 with internal threads for sealing tip 16 to tapered portion 14. An outwardly projecting threaded portion 26 can be provided as part of the. Alternatively, the threaded part z6 can be joined and fixed to the tip part 16 in a known manner.

3, 8a and 86, the apex tip portion 11
6 has a rectangular cross section and the outlet hole 11? A specific example of the present invention having the following is shown. As shown, one tip 116 is a replaceable element that can be connected to a cyclone member using threads 126.

1 as shown in Figures 3, za and 8b.
The inner wall 101 of the hollow tapered body portion of the apex tip 116 gradually changes from a circular cross section to a square cross section over a portion of the length of the apex tip 116 . - tapered wall portions 10g, 104.106.1, which together form a tapered passageway with a square cross section;
08 may be integrally molded into the molded central end member of the apex point (as shown) or affixed to the apex by suitable means after the apex has been formed.

The action of the tip portion is improved by using an outlet of non-circular cross-section so that at least a portion of the inner wall of the tip portion leading to the outlet opening 11 is shown in detail in FIGS. It has been found that further improvement can be achieved by starting with a rectangular cross section and gradually making it have the same cross-sectional shape as the exit. The exact distance and angle of the taper depends on many factors, including the original dimensions and diameter of the cyclonic separator and the desired cross-sectional area of the exit opening.

It will of course be appreciated that different portions of the inner wall 101 have different taper angles. That is, as the cross-section of the separator is gradually changed from circular to non-circular, some portions of the wall make a smaller angle to the longitudinal axis of the separator than other wall portions. For example, Figures 2, 3a and 2h
Tapered wall section ios% as shown in the figure
104.106.108 are the wall portions 108.10 located between these wall portions with respect to the longitudinal axis of the separator.
6.10? , 109.

For example, if a portion of the inner wall of the separator is removed to form a square outlet nominally in inches from a circular outlet of the same diameter,
The interior wall portions located along lines ending at each of the four corners of the completed outlet form a greater angle with respect to the longitudinal axis of the separator than other wall portions because some portions of the interior wall have been removed. In this specification, it has been stated that the inner wall of the separator gradually changes from a circular shape to a non-circular shape, but this expression is meant to include both of the above cases.

In another embodiment of the invention shown in FIGS. 3 and 8a,
The apex tip portion 216 is the exit portion 21 with an octagonal cross section? have. As shown, the pointed portion 216 is adapted to be connected to the cyclone member using threads 226. The inner wall 201 of the tip member 216 changes from a circular cross-section to an octagonal cross-section over a portion of the length of the tip. - tapered wall portions 202.204.206 which together form an octagonal tapered passage;
is the provision.

In the embodiment of the invention shown in FIGS. 4 and 4a, the top tip portion 816 is provided with a rectangular or oval outlet aperture 817. The oval exit hole 817 is located at the tip portion 816.
This is the result of forming the end portion at an angle with respect to an axis perpendicular to the longitudinal axis of the tip portion. This angle is 1@b in order to change the degree to which the exit hole 817 is deformed from the circular cross section.
・Can be changed over a range of 89°. Alternatively, the tip portion 816 can be formed with an oblong outlet having an end perpendicular to its longitudinal axis.

As previously mentioned, the tip portion 816 may include threads 8z6 to secure it to the cyclone member.

The embodiment of the invention shown in FIGS. 5 and 56 uses threads 436 to provide a polygonal or serrated exit portion 4 at the apex point 416 for connection to the cyclone member.
17 is the provision. The inner wall 401 of the tip member 416 varies from a circular cross section to a polygonal cross section WK over a distance along the length of the tip member. Tapered wall section 402.4
0B, 404.405.406.40? ,409,41
0.411% 412.418.414.415.41
9. 420 has a polygonal cross section and the exit 417 is a trap.
It forms a tapered passage giving a sawtooth effect.

In order to better understand the present invention, the present invention will be explained with reference to some examples below, but the present invention is not limited to these examples.

EXAMPLE 1 Several tests were carried out using deinked stock from the impassable section of stage 8 of a cyclonic separation system as feed stock. The Black Crown Company, located in Mitsdoltown, Ohio, participated in this test.
Lack Clawson Cotton' / eM
8-inch diameter Nocellu-Clon cyclone cleaner (Cgllu-C) manufactured by Iddlatown, 0hio)
1 osecylone clearer) was used. The tip portions of four types of rejects were tested as follows.

1. Standard tip - circular cross section, 0.86 inch diameter (0
, 108 square inches open area) 8. Point A - circular cross section, 0.1a5 inch diameter (0
,049 square inches open area) 8. Point B - Square cross section, 0.25 inch sides, tapered (0,068 square inch open area) 4. Point C - Oval cross section, 0.178 inch XL1 .865
The results of the inch (o, o a a square inch open area) test are shown below. In tests 1 to 4, the flow of rejects was transferred to a cyclo7 separator 1llt.
Controlled by a retentate valve provided at c. Tests 8 to 8 were carried out with the storage room wide open to avoid valve blockage. A free drainage arrangement was provided so that non-passage material from the apparatus was discharged into an open pipe located approximately 8 feet above the apparatus. This delivery created approximately 805 psi of back pressure on the reject stock. The defined pressure drop across the device K was 20 p#- in all tests.

As can be seen from No. 19, test 8 and ?K were conducted using a square tip. At 0 visual acuity, the percentage of retentate and the concentration factor were significantly lower than when using standard round tips (test drugs 1 and 5) and tip A (tests 2 and 6). It was observed that the cleaning effect was almost the same for all tip parts. No occlusion occurred in any apical region. The rectangular tip C (tests 4 and 8) represents a significantly higher concentration factor and can be used when high consistency is desired.

Example 2 Points were tested using the same arrangement as in Example 1 except that a corrugated feed of kraft paper and a mixture of chips and fragments were used as the feed stock. The results of this test are shown in Table 2 below. Again, the pressure drop across the device was measured at 2.0 psi in all tests.

In this example as well, tip section B (Test 10) had a significantly lower percentage of rejects than the standard circular tip section (Test 9). The cleaning effect was almost the same for all the tip portions where no blockage occurred. As before, K
, the oblong tip C (trial, run 11) showed a significantly higher concentration factor than the standard circular tip.

Example 8 Further tests were conducted using the feed of Example 1 at a higher consistency (i.e., about 1.0-). The results of this test are shown in Table 8 below.

The pressure drop measured across the device was i! for all tests. It was Opat.

In this example, even though the consistency of the feed was higher, the rectangular tip had a significantly lower retentate fraction and concentration factor. No occlusion was observed in this case either.

Example 4 Further tests were conducted using the feed of Example 1.

The new tip section was also tested as follows.

Point 41 Section D - Square cross section, 0.26 inch sides, 0.068 square inch open area with no taper) "Untapered" means the walls of the tip are parallel and not sloped inward. It is. In the later tests (tests 19 and 22),
The tip was modified nine times to have a tapered wall very similar to tip B.

The results of this test are shown in Table 4 below. The pressure drop across the device was measured to be 202 si for all tests.

The test results are as follows:
20 and 22) show that the use of tapered edges improved operational performance relative to the non-tapered tip section (test 16). However, the non-tapered tip portion D (Test 1
6) still worked with a lower rejectage fraction than the standard circular cross-section tip section (test zl). In this case as well, the concentration factor was lower at the apex portion with a square cross section than at the apex portion with a circular cross section. No occlusion occurred.

Therefore, by using a non-circular cross-section reject outlet in the cyclone separator as in accordance with the present invention, the reject rate, troweling factor and feed pressure to the device also keep the cleaning efficiency approximately the same. However, changes can be made to improve the performance of the device without creating blockage problems. For example, by using the same open area in a square cross-section tip, a lower percentage of impurities can be achieved than in the prior art circular cross-section tip. If occlusion is a problem, a square cross-section tip section with a larger open area can be used with approximately the same percentage of rejects as the circular cross-section tip sections of the prior art. It will be readily apparent to those skilled in the art that further variations in the geometry of the tip may be made to suit performance under varying conditions of delivery pressure and consistency.

Although the apparatus of the present invention has been described with reference to its preferred specific example, it should be understood that the present invention is not strictly limited to this specific example and that this specific example can be modified in various ways without departing from the scope of the present invention. However, the present invention is limited only by the scope of the claims.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a typical cyclone separator with a rejects outlet; Figures 2, 8, 4 and 5 are cyclone separators with the rejects outlet pointing downwards; The top view, Figure 2, Figure 8, Figure 4a, and Figure 5a are side sectional views of the retentate outlet, and Figures S & Figure 26 are
Figure mk-BklIil! FIG. Wall means 101, 201, 401. Exit 11? , 21? ,
81? , 417(1)

Claims (1)

Claims: α) Means for forming a separation chamber, the first end of which has a generally circular cross-section and includes a tangential inlet and a central outlet; A cyclonic separator, characterized in that the cyclonic separator is tapered towards an outlet with a flow area smaller than the separation chamber, characterized in that the cyclonic separator is provided with wall means forming an outlet with a non-circular cross-section. (2) A cyclone separator according to claim 1, in which the outlet has a rectangular cross section. (3) A cyclone separator according to claim 1, in which the outlet has a triangular cross section. (4) The cyclone separator according to claim 1, wherein the outlet has a polygonal cross section. (5) The cyclone separator according to claim 1, wherein the outlet has a rectangular cross section. (6) Patent binding (7) in which at least a part of the inner wall of the other end gradually changes to have the same cross-sectional area as the outlet.
An apex tip of a cyclonic separator comprising a hollow tapered body portion having an inner wall that gradually changes from a circular cross-section near the inlet end to a non-circular cross-section at the outlet end. (8) The apex tip member according to claim 7, wherein the outlet has a square cross section. (9) The apex point member according to claim 7, wherein the outlet has an octagonal cross section. 00) The apex point member of claim 7, wherein the outlet has a polygonal cross section. (11) The apex point member according to claim 7, wherein the outlet has a rectangular cross section.