A pressure knot removal machine

Abstract

The present invention discloses a pressure knot remover, which belongs to the technical field of pressure screen equipment for papermaking and pulping. The pressure knot remover comprises a closed screen chamber, an upper cover is arranged on the top of the closed screen chamber, a closed cylinder is coaxially arranged at the bottom of the closed screen chamber, an annular step is arranged on the inner wall of the closed screen chamber corresponding to the middle and lower part of the closed cylinder, an annular frame is connected between the annular step and the closed cylinder, a vertical rotating shaft is coaxially rotatably connected in the closed cylinder, the bottom end of the vertical rotating shaft extends out of the closed screen chamber and a transmission wheel is arranged at the end thereof, the top end of the vertical rotating shaft extends upward out of the closed cylinder, a screen drum is sleeved on the closed cylinder, the top end of the screen drum is transmission-connected to the vertical rotating shaft through a rotating disk, and the bottom end of the screen drum is sealingly rotatably connected to the annular step, so as to realize a screening device specifically for multi-knots and multi-fiber bundles.

Description

Technical Field

[0001] The invention belongs to the technical field of pressure screen equipment for papermaking and pulping, and particularly relates to a pressure knot remover, which is particularly suitable as a knot remover for various plant fiber raw materials. Background Art

[0002] At this stage, as the most widely used screening equipment in the pulping line of the domestic papermaking industry, the pressure screen technology is becoming more and more mature. Domestic manufacturers have also gradually transitioned from the initial technology introduction to technological innovation, making adjustments to the pressure screen from various aspects to make it more suitable for domestic papermaking enterprises.

[0003] The Chinese patent, publication number CN2048870U discloses a pressure knot removal screen, which is composed of a qualified pulp collection chamber, a coarse slag separation chamber, a drive shaft and a rotor. The qualified pulp collection chamber is provided with a pulp outlet pipe, and the coarse slag separation chamber is provided with a pulp inlet pipe and a slag discharge pipe. The qualified pulp collection chamber is located above the coarse slag separation chamber, and there is a set of planar coaxial annular screen slots composed of a coaxial moving ring on the rotor and a coaxial static ring on the housing of the qualified pulp collection chamber between the two, which prevents coarse slag larger than the screen slot from passing through the screen slot. The advantages of the present invention are high knot removal efficiency, low power consumption, the screen slot is not easy to be blocked, no water dilution is required, and the inlet pulp concentration can be as high as 5%.

[0004] The Chinese journal "Paper and Papermaking" published on pages 8-10 of Volume 28, Issue 7, 2009, disclosed a new domestically produced high-concentration internal flow rotary drum pressure knotter, mainly introducing the basic structure, working principle and application of the new domestically produced pressure knotter. The internal flow rotary drum pressure knotter has a large passing capacity, good knot removal effect, less good pulp content in the tail slurry, less wear on the screen drum due to heavy impurities, and light impurities will not adhere to the screen drum. Even if it runs at a higher concentration, it will not clog the screen holes. It has an advanced structure and reliable performance.

[0005] Due to the large number of fiber bundles formed by incomplete cooking and fibers and knots that cannot be formed by cooking in chemical-mechanical pulping and papermaking, the traditional rotary pressure screen is inefficient in screening knots and fiber bundles, has low screening output and is prone to clogging, affecting production efficiency. Therefore, it has become an urgent problem to be solved to develop a screening device specifically for multiple knots and multiple fiber bundles. Summary of the invention

[0006] The purpose of the present invention is to provide a pressure knot remover; the technical solution adopted to achieve the above purpose is:

[0007] A pressure knot remover comprises a closed screen chamber, an upper cover is arranged on the top of the closed screen chamber, a closed cylinder is coaxially arranged at the bottom of the closed screen chamber, an annular step is arranged on the inner wall of the closed screen chamber corresponding to the middle and lower part of the closed cylinder, an annular frame is connected between the annular step and the closed cylinder, a vertical rotating shaft is coaxially connected and rotatably arranged in the closed cylinder, the bottom end of the vertical rotating shaft extends out of the closed screen chamber and a transmission wheel is arranged at the end thereof, the top end of the vertical rotating shaft extends upwardly out of the closed cylinder, a screen drum is sleeved on the closed cylinder, the top end of the screen drum is transmission-connected to the vertical rotating shaft through a rotating disk, and the bottom end of the screen drum is sealingly and rotatably connected to the annular step;

[0008] The space between the screen drum and the closed screen chamber is the outer screening area, and the space between the screen drum and the closed cylinder is the inner screening area. A tangential slurry inlet pipe connected to the top of the outer screening area is provided at the upper part of the closed screen chamber, a tangential heavy slag discharge pipe connected to the bottom of the outer screening area is provided at the lower part of the closed screen chamber, a light slag discharge pipe connected to the top of the outer screening area is provided on the upper cover, and a tangential slurry discharge pipe connected to the bottom of the inner screening area is provided at the bottom of the closed screen chamber.

[0009] Preferably, a plurality of cantilever wings arranged in the vertical direction are provided around the circumference of the closed cylinder, and the outer side surface of the cantilever wings is a folding surface. With the rotation direction of the screen drum as the front direction, the gap between the folding surface and the inner wall of the screen drum increases step by step from the front to the rear direction, thereby forming a reverse buffer zone between the folding surface and the inner wall of the screen drum.

[0010] Preferably, the bottoms of the cantilever bottom screen drums are aligned.

[0011] Preferably, a detachable liner cylinder is provided on the inner wall of the closed screening chamber corresponding to the outer screening area.

[0012] Preferably, a plurality of spoiler assemblies are circumferentially arranged on the bottom of the upper cover.

[0013] Preferably, a washing water pipe is provided on the tangential heavy slag discharge pipe, and the water inlet direction of the washing water pipe is arranged along the heavy slag discharge direction in the tangential heavy slag discharge pipe.

[0014] Preferably, a dilution water pipe connected to the inner screening area is provided at the bottom of the closed screening chamber.

[0015] Preferably, a suspension arm is hinged on the upper cover, and the free end of the suspension arm is connected to the upper cover via a rotating bolt.

[0016] Preferably, the bottom end of the screen drum and the annular step are rotatably connected via a labyrinth seal.

[0017] Preferably, the closed sieve chamber comprises an upper cylinder and a lower cylinder connected by a first flange, and the upper cover is connected to the top of the upper cylinder by a second flange.

[0018] The beneficial effects of the present invention are as follows: (1) the screen drum divides the closed screen chamber into an outer screening area and an inner screening area, and the whole screen chamber works under pressure and continuous screening in a completely sealed state. Impurities are separated in the outer screening area, and qualified good pulp enters the inner screening area through the screen holes under the pressure difference between the inside and outside of the screen drum, and is discharged from the tangential pulp discharge pipe at the bottom. It is particularly suitable for screening fiber bundles and pulp with many fibers and knots that cannot be formed by cooking;

[0019] (2) The pulp in the reverse buffer zone produces a periodic pulse-like backwashing effect on the screen holes of the screen drum, which allows the pulp to pass through the screen holes smoothly, thereby ensuring efficient and continuous operation of the screening;

[0020] (3) The detachable liner cylinder is arranged on the inner wall of the closed screen chamber, that is, the liner cylinder is easy to install and disassemble. When the liner cylinder is damaged, it only needs to be replaced. The operation is simple and fast, saving costs;

[0021] (4) A plurality of spoiler plates are provided around the bottom of the upper cover, which can reduce the rotation of the upper light slag and facilitate its discharge from the light slag discharge pipe 5, and reduce the wear on the upper cover;

[0022] (5) A small amount of washing water is added to the tangential heavy slag discharge pipe through the washing water pipe, thereby washing the heavy slag and further reducing the loss of slag;

[0023] (6) A dilution water pipe connected to the inner screening area is provided at the bottom of the closed screening chamber. The good pulp screening in the inner screening area can be diluted with dilution water through the dilution water pipe to adjust the screening concentration and improve the screening efficiency;

[0024] (7) In order to facilitate the overall assembly and lifting, the closed screen chamber includes an upper cylinder and a lower cylinder connected by a first flange, and the upper cover is connected to the top of the upper cylinder by a second flange; a suspension arm 4 is hinged on the upper cover, and the free end of the suspension arm is connected to the upper cover by a rotating bolt;

[0025] (8) The annular step is divided into a horizontal connecting ring and a vertical connecting ring connected to each other by bolts. In this way, the vertical connecting ring can be strengthened and thickened separately. Even if it needs to be replaced, only the vertical connecting ring needs to be replaced, thereby reducing the occurrence of downtime, increasing service life, and reducing maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the present invention;

[0027] Figure 2 for Figure 1 A partial sectional view of the right side view;

[0028] Figure 3 for Figure 2 Partial cross-sectional view along AA direction;

[0029] Figure 4 for Figure 2 A magnified view of the N part;

[0030] Figure 5 for Figure 2 Enlarged view of the middle M section. DETAILED DESCRIPTION

[0031] The present invention is further described below in conjunction with the accompanying drawings.

[0032] like Figures 1 to 5 As shown, a pressure knot remover comprises a closed screen chamber 7, a top cover 6 is arranged on the top of the closed screen chamber 7, a closed cylinder 12 is coaxially arranged at the bottom of the closed screen chamber 7, an annular step 23 is arranged on the inner wall of the closed screen chamber 7 corresponding to the lower middle part of the closed cylinder 12, an annular frame 14 is connected between the annular step 23 and the closed cylinder 12, a vertical shaft 10 is coaxially rotatably connected in the closed cylinder 12, the bottom end of the vertical shaft 10 extends out of the closed screen chamber 7 and a transmission wheel 11 is arranged at the end thereof, the top end of the vertical shaft 10 extends upward out of the closed cylinder 12, a screen drum 20 is sleeved on the closed cylinder 12, the top end of the screen drum 20 is transmission-connected to the vertical shaft 10 through a rotating disk 16, and the bottom end of the screen drum 20 is rotationally connected to the annular step 23 through a labyrinth sealing structure 24;

[0033] The space between the screen drum 20 and the closed screen chamber 7 is the outer screening area 19, and the space between the screen drum 20 and the closed cylinder 12 is the inner screening area 21. A tangential pulp inlet pipe 3 connected to the top of the outer screening area 19 is provided at the upper part of the closed screen chamber 7, a tangential heavy slag discharge pipe 2 connected to the bottom of the outer screening area 19 is provided at the lower part of the closed screen chamber 7, a light slag discharge pipe 5 connected to the top of the outer screening area 19 is provided on the upper cover 6, and a tangential pulp discharge pipe 9 connected to the bottom of the inner screening area 21 is provided at the bottom of the closed screen chamber 7.

[0034] A plurality of cantilevers 15 arranged in the vertical direction are circumferentially provided on the closed cylinder 12, preferably four of them are selected, the bottom of the cantilever wing 15 is aligned with the bottom of the screen drum 20, the outer side surface of the cantilever wing 15 is a folding surface, and the rotation direction L of the screen drum 20 is taken as the front direction, and the gap between the folding surface and the inner wall of the screen drum 20 increases step by step from the front to the rear direction, thereby forming a reverse buffer zone 22 between the folding surface and the inner wall of the screen drum 20. During the rotation of the screen drum 20, the pulp reversely impacts and enters the reverse buffer zone 22, thereby generating a periodic pulse-type recoil cleaning effect on the screen holes of the screen drum 20, so that the pulp can continuously and smoothly pass through the screen holes, thereby ensuring efficient and continuous operation of screening.

[0035] At the same time, in order to prevent the heavy slag thrown out at high speed from directly hitting the inner wall of the closed screen chamber 7 and accelerating damage and reducing service life, reducing downtime and equipment maintenance costs, a detachable liner cylinder 18 is provided on the inner wall of the closed screen chamber 7 corresponding to the outer screening area 19, that is, the liner cylinder 18 is easy to install and disassemble. When the liner cylinder 18 is damaged, it only needs to be replaced, which is simple and fast to operate and saves costs. On the other hand, a plurality of spoiler assemblies 17 are circumferentially provided at the bottom of the upper cover 6, one is to reduce the rotation of the upper light slag, which is easy to be discharged from the light slag discharge pipe 5, and the other is to reduce the wear on the upper cover 6.

[0036] Since the heavy slag in the tangential heavy slag discharge pipe 2 contains some fibers, a washing water pipe 1 is provided on the tangential heavy slag discharge pipe 2. The water inlet direction of the washing water pipe 1 is arranged along the heavy slag discharge direction in the tangential heavy slag discharge pipe 2, so that the washing water entering from the washing water pipe 1 is used for washing to reduce fiber loss. A dilution water pipe 8 connected to the inner screening area 21 is provided at the bottom of the closed screen chamber 7. The good pulp screening in the inner screening area 21 can be diluted with dilution water through the dilution water pipe 8 to adjust the screening concentration and improve the screening efficiency.

[0037] In order to facilitate the overall assembly and lifting, the closed screen chamber 7 includes an upper cylinder and a lower cylinder connected by a first flange, and the upper cover 6 is connected to the top of the upper cylinder by a second flange; a suspension arm 4 is hinged on the upper cover 6, and the free end of the suspension arm 4 is connected to the upper cover 6 by a rotating bolt.

[0038] When the present invention is working, when the pulp enters the outer screening area 19 tangentially through the tangential pulp inlet pipe 3, the vertical rotating shaft 10 drives the screen drum 20 to rotate for screening. The high-speed rotating screen drum 20 prevents impurities in the pulp from entering the inner screening area 21. In particular, large and heavy impurities such as knots will be thrown into the outer screening area 19 and finally fall to the bottom and be regularly discharged from the tangential heavy slag discharge pipe 2. Tail pulp and light impurities float on the top and are regularly discharged from the light slag discharge pipe 5. Qualified good pulp passes through the screen drum 20 and enters the inner screening area 21. The present invention as a whole works under pressure and continuous screening in a completely sealed state. Under the action of the pressure difference between the inside and outside of the screen drum 20, qualified good pulp enters the inner screening area 21 through the sieve holes under the action of pressure and is discharged from the tangential pulp discharge pipe 9 at the bottom.

[0039] During the screening process, a small amount of flushing water in the washing water pipe 1 flushes the heavy impurities and separates the qualified fibers mixed with the heavy impurities, reducing the loss of fibers in the heavy impurities; the good pulp screening in the inner screening area 21 can be diluted with water through the dilution water pipe 8 to adjust the screening concentration and improve the screening efficiency; the pulp reversely impacts and enters the reverse buffer zone 22, thereby generating a periodic pulse backwashing effect on the screen holes of the screen drum 20 to clean the screen holes, so that the pulp can continuously and smoothly pass through the screen holes, thereby ensuring efficient and continuous operation of the screening.

[0040] After the heavy slag falls on the bottom of the outer screening area 19, the heavy slag and the annular step 23 are seriously rubbed under the driving effect of the high-speed rotation of the screen drum 20. It is easy to wear it out over time, causing the heavy slag to enter the inner screening area 21 and mix with the good pulp. Therefore, if Figure 5 As shown, in this embodiment, the annular step 23 is divided into a horizontal connecting ring 26 and a vertical connecting ring 25 which are interconnected by bolts, and the bottom end of the screen drum 20 is rotatably connected to the vertical connecting ring 25 via a labyrinth sealing structure 24; in this way, the vertical connecting ring 25 can be strengthened and thickened separately, and even if it is replaced, only the vertical connecting ring 25 needs to be replaced, thereby reducing the occurrence of downtime, increasing service life, and reducing maintenance costs.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pressure knot remover, comprising a closed screen chamber, a cover is provided on the top of the closed screen chamber, characterized in that: A closed cylinder is coaxially arranged at the bottom of the closed screen chamber, an annular step is arranged on the corresponding inner wall of the closed screen chamber in the middle and lower part of the closed cylinder, an annular frame is connected between the annular step and the closed cylinder, a vertical rotating shaft is coaxially connected and rotated in the closed cylinder, the bottom end of the vertical rotating shaft extends out of the closed screen chamber and a transmission wheel is arranged at the end thereof, the top end of the vertical rotating shaft extends upward out of the closed cylinder, a screen drum is sleeved on the closed cylinder, the top end of the screen drum is transmission-connected to the vertical rotating shaft through a rotating disk, and the bottom end of the screen drum is sealingly and rotationally connected to the annular step; The space between the screen drum and the closed screen chamber is the outer screening area, and the space between the screen drum and the closed cylinder is the inner screening area. A tangential pulp inlet pipe connected to the top of the outer screening area is provided at the upper part of the closed screen chamber, a tangential heavy slag discharge pipe connected to the bottom of the outer screening area is provided at the lower part of the closed screen chamber, a light slag discharge pipe connected to the top of the outer screening area is provided on the upper cover, and a tangential pulp discharge pipe connected to the bottom of the inner screening area is provided at the bottom of the closed screen chamber; A plurality of spoiler assemblies are arranged around the bottom of the upper cover; A washing water pipe is arranged on the tangential heavy slag discharge pipe, and the water inlet direction of the washing water pipe is arranged along the heavy slag discharge direction in the tangential heavy slag discharge pipe.

2. The pressure knot remover according to claim 1, characterized in that: A plurality of cantilever wings arranged in the vertical direction are arranged around the circumference of the closed cylinder, and the outer side surface of the cantilever wings is a folding surface. With the rotation direction of the screen drum as the front direction, the gap between the folding surface and the inner wall of the screen drum increases step by step from the front to the rear direction, thereby forming a reverse buffer zone between the folding surface and the inner wall of the screen drum.

3. The pressure knot remover according to claim 2, characterized in that: The bottom of the cantilever bottom screen drum is aligned.

4. The pressure knot remover according to claim 1, characterized in that: A detachable liner cylinder is provided on the inner wall of the closed screening chamber corresponding to the outer screening area.

5. The pressure knot remover according to claim 1, characterized in that: A dilution water pipe connected with the inner screening area is arranged at the bottom of the closed screening chamber.

6. The pressure knot remover according to any one of claims 1 to 4, characterized in that: A suspension arm is hinged on the upper cover, and a free end of the suspension arm is connected to the upper cover through a rotating bolt.

7. The pressure knot remover according to any one of claims 1 to 4, characterized in that: The bottom end of the screen drum and the annular step are rotatably connected via a labyrinth seal.

8. The pressure knot remover according to any one of claims 1 to 4, characterized in that: The closed sieve chamber comprises an upper cylinder and a lower cylinder connected by a first flange, and an upper cover is connected to the top of the upper cylinder by a second flange.

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