Environmentally friendly white water pulp recycling device and method for recycling pulp

Abstract

The present invention provides an environment-friendly white water pulp recycling device, comprising: a tower body, which is a cylindrical body, the lower part of which is in a conical shape, the upper part of which is provided with a water outlet, the lower end of the conical body is provided with an outlet, a cover is arranged at the upper end of the cylindrical body, and an installation hole is arranged on the cover; a rolling cylinder, which is a cylindrical body, is vertically arranged in the tower body, the upper part of the cylindrical body extends out of the installation hole in a sealed manner, the upper port of the rolling cylinder is closed by a sealing plate, a white water inlet is opened on the sealing plate to connect a white water inlet pipe and a water return port, a water return pipe is connected between the water return port and the water outlet, and a pump device is arranged on the water return pipe; a water storage area is formed between the inner wall surface of the tower body and the outer wall surface of the rolling cylinder, the water outlet on the tower body is located at the upper part of the water storage area, and the lower part of the rolling cylinder is an outward-expanded conical section; a baffle plate, which is an annular plate, is arranged on the inner peripheral wall of the tower body, is located below the rolling cylinder, and corresponds to the annular lower port of the water storage area up and down with a gap between the baffle plate and the lower port of the rolling cylinder, and the diameter of the inner opening of the baffle plate is smaller than the diameter of the lower port of the rolling cylinder. The present invention also provides a pulp recycling method.

Description

Technical Field

[0001] The present invention belongs to the technical field of papermaking white water treatment, and particularly relates to an environment-friendly white water pulp recycling device. The present invention also provides a method for recycling pulp. Background Art

[0002] During the papermaking process, white water is generated. There are two common methods for treating white water. One is to directly discharge it into the municipal pipeline, and the pulp contained in the white water is completely lost. In this direct discharge method, the pulp loss rate reaches about 0.05%. At the same time, it will also cause environmental pollution. The other treatment method is to press it into pulp mud with polyacrylamide, with a content of more than 10%, and then utilize the pulp mud. The disadvantage of this treatment method is that additives are required during the treatment process, resulting in costs. In addition, there is also pulp loss during the treatment process. Summary of the Invention

[0003] The purpose of the present invention is to improve the problems of the existing technology and provide an environment-friendly white water pulp recycling device to more efficiently recycle the pulp in the white water and be beneficial to environmental protection.

[0004] Another purpose of the present invention is to provide a method for treating white water using the environment-friendly white water pulp recycling device.

[0005] The purpose of the present invention is achieved as follows:

[0006] An environment-friendly white water pulp recycling device includes a tower body, a rolling cylinder, and a baffle.

[0007] The tower body is a cylinder, the lower part of the cylinder is in a conical shape, a water outlet is arranged at the upper part of the cylinder, an outlet is arranged at the lower end of the conical shape, a cover is arranged at the upper end of the cylinder, and an installation hole is arranged on the cover.

[0008] The rolling cylinder is a cylinder, which is vertically arranged in the tower body. The upper part of the cylinder extends out of the installation hole in a sealed manner and is fixed. The upper port of the rolling cylinder is closed by a sealing plate. A white water inlet is opened on the sealing plate to connect to a white water inlet pipe, and a water return port is also opened. A water return pipe is connected between the water return port and the water outlet on the tower body, and a pump device is arranged on the water return pipe.

[0009] An annular space is arranged between the inner wall surface of the tower body and the outer wall surface of the rolling cylinder, and this space forms a water storage area. The water outlet on the tower body is located at the upper part of the water storage area. The lower part of the rolling cylinder is an outward-expanded conical section, and a flared opening is formed at the lower end to narrow the lower port of the water storage area.

[0010] The baffle is an annular plate fixedly arranged on the inner peripheral wall of the tower body, located below the tumbling cylinder, vertically corresponding to the annular lower port of the water storage area with a gap between the lower port of the tumbling cylinder, and the inner diameter of the baffle is smaller than the diameter of the lower port of the tumbling cylinder.

[0011] Preferably, the diameter D of the tower body 塔 and the diameter D of the tumbling cylinder 滚 are related as follows:

[0012] D 塔 =(1.5 - 2.5)D 滚滚 (1)

[0013] More preferably, the diameter of the tumbling cylinder is half of the diameter of the tower body.

[0014] Preferably, the height H of the upper cylindrical section of the tower body 塔 and the total height H of the tumbling cylinder 滚 are related as follows:

[0015] H 塔 =(1.5 - 2.5)H 滚 (2)

[0016] More preferably, the total height of the tumbling cylinder is half of the height of the upper cylindrical section of the tower body.

[0017] A pulp discharge pipe is connected to the outlet at the lower end of the lower conical body of the tower body, a valve is provided thereon, and a pump device is also provided.

[0018] Preferably, the water outlet is opened 1 meter downward from the upper end of the tower body.

[0019] Preferably, the upper port of the tumbling cylinder is 0.15 - 0.3 meters higher than the upper end cover of the tower body. The optimal value is 0.2 meters.

[0020] Preferably, the distance between the lower port of the conical section with an outward expansion at the lower part of the tumbling cylinder and the inner wall of the tower body is 40 - 60% of the distance between the outer wall surface of the tumbling cylinder and the inner wall surface of the tower body, and the optimal value is 50%.

[0021] Preferably, the horizontal projection length L of the conical section at the lower part of the tumbling cylinder 水平 and the distance L between the tumbling cylinder and the tower body 间距 are related as follows:

[0022] L 水平 =(0.3 - 0.7)L 间距 (3)

[0023] More preferably, the horizontal projection length of the tapered segment is half of the spacing.

[0024] Preferably, the baffle is a downwardly inclined conical plate, and the inclination angle of the baffle is preferably 43°-46°, with the optimal value being 45°.

[0025] Preferably, the vertical gap between the baffle and the lower port of the tumble drum is 0.15-0.3 meters, and the optimal value is 0.2 meters.

[0026] Preferably, the horizontal projection length L of the baffle is 挡水平 The distance L between the tumble drum and the tower body 间距 equal.

[0027] A wiper may be provided on the baffle and / or the tumble drum, and the wiper is connected to a driving mechanism.

[0028] The principle of separating pulp from white water in the environment-friendly white water pulp recovery device provided by the present invention is as follows: white water enters the tumble drum from the white water inlet of the tumble drum, then flows downward to the middle of the tumble drum entering the tower body, and after reaching the bottom of the tower body, flows upward along the inclined wall of the lower cone, and then flows upward to the bottom of the baffle, and then bypasses the baffle upward, and enters the water storage area through the gap between the tumble drum and the baffle. Before entering the water storage area, a part of the pulp in the white water has been precipitated and separated in the flow channel with a constantly changing flow cross section provided by the tumble drum, the tower body and the baffle. After re-precipitation in the water storage area, the content of pulp in the liquid discharged from the water outlet will be greatly reduced. The separation of pulp can reach 90%. Furthermore, the tower body, the tumble drum and the baffle in the environment-friendly white water pulp recovery device have the above-mentioned size relationship and corresponding relationship, which can ensure that the white water containing pulp is efficiently separated therein.

[0029] In order to separate the pulp more fully, the environmentally friendly white water pulp recovery device can also be connected to a sedimentation tank, and a pipe is connected to the water outlet to introduce the white water into the sedimentation tank to further precipitate and separate the pulp.

[0030] The method for recovering pulp using the white water pulp recovery device is:

[0031] Step 1: inject white water into the tumble drum from the white water inlet pipe on the upper end plate of the tumble drum;

[0032] Step 2: The treated water discharged from the water outlet on the tower body is selectively subjected to one of the following steps:

[0033] Step A. Qualified treated water is directly discharged;

[0034] Step B. Unqualified treated water:

[0035] It passes through the water return pipe from the water outlet, enters the tumbling cylinder through the water return opening, and then returns to the tower body; or,

[0036] It is discharged from the water outlet into the sedimentation tank through a pipeline, stands for a set time, the qualified sedimented water in the upper part of the sedimentation tank is discharged, and the unqualified sedimented water in the lower part enters the tumbling cylinder again through the white water inlet pipe or the water return pipe.

[0037] Repeat Step 1 and Step 2 to continuously treat the white water into water meeting the discharge requirements and discharge it.

[0038] Open the outlet at the lower end of the tower body to discharge the sedimented pulp.

[0039] Preferably, in Step B, the clear water with a height of more than three-quarters in the sedimentation tank is discharged, and the remaining one-quarter of the sedimented water is pumped up and introduced into the tumbling cylinder again.

[0040] The environmentally friendly white water pulp recycling device provided by the present invention and the method for treating white water using this device can efficiently separate the pulp in the white water, recover the fine fibers and pulp contained in the white water, reduce raw material consumption, with a recovery rate of over 90%. At the same time, the white water is recycled and treated in this device, without white water discharge, reducing the pressure in the sewage treatment link, reducing pulp waste, and saving energy.

[0041] The present invention will be described in detail below with reference to the drawings and embodiments. Description of the Drawings

[0042] Figure 1 It is a schematic structural diagram of the environmentally friendly white water pulp recycling device provided by the present invention. Detailed Embodiment

[0043] As Figure 1 shown is a specific embodiment of the environmentally friendly white water pulp recycling device provided by the present invention. The upper part of the tower body 1 is a cylinder made of stainless steel, with a height of 20 meters, an inner diameter of 0.6 meters, and a wall thickness of 0.005 meters. The lower part is connected to a cone with a height of 3 meters. At 1 meter downward from the upper end of the tower body 1, a water outlet 2 is opened with a diameter of 0.055 meters. The water outlet 2 is connected to a drainage pipe 11 with a matching diameter. At the lower end of the lower cone of the tower body 1, an outlet 7 is opened with a diameter of 0.055 meters. The outlet 7 is connected to a pulp discharge pipe 9 with a matching diameter. The fine fibers and pulp contained at the bottom of the tower body 1 are pumped out and recovered by the power provided by the pump 13.

[0044] The upper part of the tumbling cylinder 4 is a cylindrical body, and the lower part is an outward-expanded conical section. The material used is stainless steel, with an inner diameter of 0.30 meters, a total height of 10 meters, and a wall thickness of 0.005 meters. Its upper end is equipped with a sealing plate or a cover 8, and the cover 8 is 0.20 meters higher than the upper sealing cover of the tower body. The cover 8 is provided with a water inlet 10 and a water return port 5. The water inlet is connected to the white water inlet pipe 6, and the water return port 5 is connected to the drainage pipe 11. The lower outward-expanded conical section of the tumbling cylinder 4 forms a flared opening at the lower end, and the horizontal length L of the outer extension at the lower end of the tumbling cylinder 4 水平 That is, the length of the horizontal projection of the conical section is maintained at half of the length between the inner wall surface of the tower body 1 and the outer wall surface of the tumbling cylinder 4 间距 The upper end of the tumbling cylinder 4 is hermetically connected to the tower body 1.

[0045] The baffle 3 is an annular plate, installed on the inner walls around the lower part of the tower body 1 in sections. The baffle 3 is a downward-inclined cone, with a downward inclination angle of 45 degrees. The horizontal length L of the baffle 3 挡水平 That is, the length of the horizontal projection of the cone is equal to the distance between the tower body l and the upper cylindrical body of the tumbling cylinder 4. The vertical gap between the baffle 3 and the outer extension of the lower flared opening of the tumbling cylinder 4 is 0.20 meters.

[0046] The water outlet 2 is also connected to a pipe leading to a sedimentation tank (not shown in the figure).

[0047] For the white water pulp recovery device provided by the present invention, a suitable distance is maintained between the inner wall of the tower body l and the outer wall of the tumbling cylinder 4 to form a storage area cavity; the lower part of the tower body l is conical. An outlet 2 is opened on the upper part of the outer wall of the tower body l, which is connected to the drainage pipe 11. The discharged water can be recycled into the tumbling cylinder through the pump 12 for circular treatment to continuously separate the pulp contained in the discharged water. The lower end of the tumbling cylinder 4 is a flared opening, and the horizontal length of the outer extension is maintained at half of the length between the tower body l and the outer wall of the tumbling cylinder 4, so as to facilitate making the clear water clearer and prevent the pulp in the newly introduced white water from being mixed in the clear water at the upper end; the baffle 3 is installed around the lower part of the tower body in sections, and the horizontal length of the baffle 3 is maintained at half of the length between the tower body and the outer wall of the tumbling cylinder, and it is inclined downward at a certain angle, so as to effectively prevent the pulp in the newly introduced white water from turning up and affecting the clear water at the upper end and the sedimentation effect. The baffle 3 and the outer extension of the lower flared opening of the tumbling cylinder 4 maintain a certain gap. The baffle prevents the fine fibers and pulp contained in the white water from turning up to the upper end of the sealed cavity in the tower body, that is, the storage area. If the gap is too large, it will make the pulp in the newly introduced white water turn up more and affect the clear water at the upper end and the sedimentation effect. However, if the gap is too small, it will affect the efficiency of white water treatment. There is an outlet at the bottom of the tower body l, which is connected to a pulp discharge pipe 9. A pump 13 is installed on the pulp discharge pipe 9. Through the pump 13 and the pulp discharge pipe 9, the white water with a high content of fine fibers and pulp at the conical bottom of the tower body can be recovered for papermaking.

[0048] When recycling white water pulp in papermaking using the environmentally friendly white water pulp recycling device provided by the present invention, the white water to be treated is input into the rolling cylinder 4 through the white water inlet pipe at the end of the rolling cylinder 4, and then continues to flow downward through the middle channel on the baffle 3 and enters the tower body below the baffle. When the pulp in the white water enters the lower conical body of the tower body 1, the conical body is conducive to the precipitation of the pulp. As the subsequent white water continuously enters, the liquid level of the white water in the tower body 1 rises. The pulp close to the wall surface is blocked by the baffle 3. As the liquid level of the white water pulp continues to rise, the pulp in the white water near the center is knocked down by the newly entered white water, and the white water that can rise enters the water storage area through the gap between the rolling cylinder 4 and the baffle 3. After multiple precipitations and separations, the water in the water storage area becomes much clearer and finally is discharged from the water outlet. If the pulp concentration in the water is still relatively high when detected at the water outlet, the pump device on the return pipe can be turned on to return it to the white water pulp recycling device through the water inlet for re-treatment until it meets the standard and is then discharged.

[0049] Another method is: the water discharged from the water outlet 2 of the tower body 1 first flows into the sedimentation tank outside the tower body. After the sedimentation tank regularly discharges water until 3 / 4 of the storage capacity is reached, a pump is used to return the remaining 1 / 4 of the water in the sedimentation tank to the rolling cylinder 4 through the drainage pipeline 11 for re-treatment, and so on in a cycle.

[0050] At a set time or depending on the amount of precipitated pulp in the tower body, the outlet at the lower end of the tower body is opened to discharge the precipitated pulp.

[0051] The upper port of the rolling cylinder 4 should be higher than the upper port of the tower body 1 to facilitate installation and maintenance, so that people can stand by holding the upper end of the rolling cylinder.

[0052] In addition, windshield wipers can be provided on both the baffle 3 and the rolling cylinder 4. The windshield wipers are connected to the driving mechanism to regularly brush the pulp fibers deposited on them.

Claims

1. An environmentally friendly white water pulp recycling device, characterized in that: it includes a tower body, a rolling cylinder and a baffle, the tower body is a cylinder, the lower part of the cylinder is conical, a water outlet is arranged at the upper part of the cylinder, an outlet is arranged at the lower end of the conical body, a cover is arranged at the upper end of the cylinder, and an installation hole is arranged on the cover; the rolling cylinder is a cylinder, vertically arranged in the tower body, the upper part of the cylinder extends out of the installation hole in a sealed manner and is fixed, the upper port of the rolling cylinder is closed by a sealing plate, a white water inlet is opened on the sealing plate to connect a white water inlet pipe, and a water return port is also opened. A water return pipe is connected between the water return port and the water outlet on the tower body, and a pump device is arranged on the water return pipe; an annular space is arranged between the inner wall surface of the tower body and the outer wall surface of the rolling cylinder, and the space forms a water storage area. The water outlet on the tower body is located at the upper part of the water storage area. The lower part of the rolling cylinder is an outward-expanded conical section, and a flared opening is formed at the lower end to narrow the lower port of the water storage area; the baffle is an annular plate and a downward-inclined conical plate, fixedly arranged on the inner peripheral wall of the tower body, located below the rolling cylinder, and vertically corresponds to the annular lower port of the water storage area with a gap between it and the lower port of the rolling cylinder. The diameter of the inner opening of the baffle is smaller than the diameter of the lower port of the rolling cylinder; among them, the relationship between the diameter D_tower of the tower body and the diameter D_roll of the rolling cylinder is: D_tower = (1.5 - 2.5)D_roll (1); the relationship between the height H_tower of the upper cylindrical section of the tower body and the total height H_roll of the rolling cylinder is: H_tower = (1.5 - 2.5)H_roll (2); the water outlet is opened 1 meter below the upper end of the tower body; the outlet at the lower end of the lower conical body of the tower body is connected to a pulp discharge pipe, a valve is arranged on it, and a pump device is also arranged; the upper port of the rolling cylinder is 0.15 - 0.3 meters higher than the upper end cover of the tower body; the distance between the lower port of the outward-expanded conical section at the lower part of the rolling cylinder and the inner wall of the tower body is 40 - 60% of the distance between the outer wall surface of the rolling cylinder and the inner wall surface of the tower body; the relationship between the horizontal projection length L_horizontal of the conical section at the lower part of the rolling cylinder and the distance L_spacing between the rolling cylinder and the tower body is: L_horizontal = (0.3 - 0.7)L_spacing (3); the gap in the vertical direction between the baffle and the lower port of the rolling cylinder is 0.15 - 0.3 meters; the horizontal projection length L_baffle_horizontal of the baffle is equal to the distance L_spacing between the rolling cylinder and the tower body.

2. The environmentally friendly white water pulp recycling device according to claim 1, characterized in that: a wiper is arranged on the baffle and / or the rolling cylinder.

3. The environmentally friendly white water pulp recycling device according to claim 1, characterized in that: the diameter of the rolling cylinder is half of the diameter of the tower body; and / or, the total height of the rolling cylinder is half of the height of the upper cylindrical section of the tower body; and / or, the upper port of the rolling cylinder is 0.2 meters higher than the upper end cover of the tower body; and / or, The distance between the lower port of the tapered section where the lower part of the tumbling cylinder expands outward and the inner wall of the tower body is half of the spacing between the outer wall surface of the tumbling cylinder and the inner wall surface of the tower body; and / or, The horizontal projection length of the tapered section at the lower part of the tumbling cylinder is half of the spacing between the tumbling cylinder and the tower body; and / or, The distance between the lower port of the tapered section where the lower part of the tumbling cylinder expands outward and the inner wall of the tower body is half of the distance between the outer wall surface of the tumbling cylinder and the inner wall surface of the tower body; and / or, The inclination angle of the baffle is 43° - 46°; and / or, The gap in the vertical direction between the baffle and the outer extension part of the lower end flared opening of the tumbling cylinder is 0.20 m.

4. The environmentally friendly white water pulp recycling device according to claim 3, characterized in that: The inclination angle of the baffle is 45°.

5. The method for recycling pulp using the environmentally friendly white water pulp recycling device according to any one of claims 1 to 4 is as follows: Step 1: Inject white water into the tumbling cylinder through the white water inlet pipe on the upper end plate of the tumbling cylinder. The white water enters the tumbling cylinder through the white water inlet of the tumbling cylinder, then flows downward to the middle part of the tower body through the tumbling cylinder, reaches the bottom of the tower body, and then flows upward along the inclined wall surface of the lower cone body. After that, the white water flows upward to the lower part of the baffle, then bypasses the baffle and flows upward, and enters the water storage area through the gap between the tumbling cylinder and the baffle. The liquid level of the white water in the tower body rises, and the pulp close to the wall surface is blocked by the baffle. As the liquid level of the white water pulp continues to rise, the pulp in the white water near the center is knocked down by the newly entered white water, and the white water that can rise enters the water storage area through the gap between the tumbling cylinder and the baffle. After multiple precipitations and separations, the water in the water storage area becomes much clearer and finally is discharged from the water outlet; Step 2: The treated water discharged from the water outlet of the tower body is selectively subjected to the following step: Step A. The qualified treated water is directly discharged; Step B. The untreated water that is not yet qualified: flows back to the tower body from the water outlet through the return pipe and enters the tumbling cylinder through the return water inlet; or, is discharged from the water outlet into the sedimentation tank through a pipeline, stands for a set time, the qualified sediment water in the upper part of the sedimentation tank is discharged, and the unqualified sediment water in the lower part enters the tumbling cylinder again through the white water inlet pipe or the return pipe; Repeat Step 1 and Step 2 to continuously treat the white water into water meeting the discharge requirements and discharge it.

6. The method according to claim 5, characterized in that: In Step B, three - quarters of the clear water in the upper part of the sedimentation tank is discharged, and the remaining one - quarter of the sediment water is pumped up and introduced into the tumbling cylinder again.

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