A papermaking wastewater treatment device for improving the pulp recovery rate

Abstract

The present invention discloses a papermaking wastewater treatment device for improving the pulp recovery rate, which includes a cylinder body. A support seat is installed at the lower end of the cylinder body. A plurality of annular electric heating plates are connected to the inner wall of the cylinder body. A feeding port is installed at the upper end of the cylinder body; a stirring mechanism, the stirring mechanism includes a rotating pipe rotatably connected to the inner bottom of the cylinder body. A plurality of stirring shafts are fixedly connected to the outer side of the rotating pipe. The lower end of the rotating pipe extends to the outside. A high-pressure box body is fixedly connected to the right side of the cylinder body. A double-shaft motor is installed on the right side of the high-pressure box body. Synchronous wheels are installed on the lower output shaft of the double-shaft motor and the outer side of the rotating pipe respectively. The two synchronous wheels are connected by a synchronous belt; a gas supply mechanism, the gas supply mechanism is used to increase the oxygen content of the wastewater. During the use of this wastewater treatment device, the water body containing a dispersant is degraded by means of biodegradation to remove the dispersant, thereby improving the pulp recovery rate.

Description

Technical Field

[0001] The present invention relates to the field of pulp wastewater treatment, and particularly to a papermaking wastewater treatment device for improving pulp recovery rate. Background Art

[0002] In China's papermaking industry, straw and wood pulp are mainly used as raw materials, and the production process usually includes processes such as pulping, washing pulp, bleaching, and papermaking. According to different pulping methods (such as alkaline pulping, chemimechanical pulping, and mechanical pulping), raw material types, pulp yield, and whether there is chemical recovery, etc., the components of the wastewater generated during the papermaking process vary greatly, but generally contain a large amount of suspended solids, high concentrations of biochemical oxygen demand (BOD), chemical oxygen demand (COD), and some toxic substances. Therefore, the treatment of papermaking wastewater mostly adopts a combination of physicochemical and biological treatment methods to ensure the effective removal of pollutants;

[0003] In the prior art, during the pulp production process, in order to assist retention and filtration, prevent deposition, and optimize the paper properties, an additive called "papermaking dispersant", such as polyacrylamide, is usually added to the pulp to increase the viscosity of the pulp, promote the uniform distribution of fibers and fillers, thereby ensuring the quality and smoothness of the paper, improving the stability of the production process, reducing paper breakage and dusting problems, enhancing the wet and dry strength of the paper and saving raw materials. When these dispersants enter the wastewater system subsequently, the suspended solids in the wastewater are not easily settled, resulting in fiber dispersion, being not easy to collect and treat, and affecting the pulp recovery rate. Therefore, how to solve this problem needs to be considered. Summary of the Invention

[0004] The purpose of the present invention is to solve the drawbacks existing in the prior art, and to propose a papermaking wastewater treatment device for improving pulp recovery rate. During the use of this wastewater treatment device, the water body containing the dispersant is degraded by means of biodegradation to remove the dispersant, thereby improving the pulp recovery rate.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A papermaking wastewater treatment device for improving the pulp recovery rate, comprising a cylinder body, a support seat is installed at the lower end of the cylinder body, a plurality of annular electric heating plates are connected to the inner wall of the cylinder body, and a feeding port is installed at the upper end of the cylinder body; a stirring mechanism, the stirring mechanism includes a rotating pipe rotatably connected to the inner bottom of the cylinder body, a plurality of stirring shafts are fixedly connected to the outer side of the rotating pipe, the lower end of the rotating pipe extends to the outside, a high-pressure box body is fixedly connected to the right side of the cylinder body, a double-shaft motor is installed on the right side of the high-pressure box body, synchronous wheels are installed on the lower output shaft of the double-shaft motor and the outer side of the rotating pipe, and the two synchronous wheels are connected by a synchronous belt; a gas supply mechanism, the gas supply mechanism is used to increase the oxygen content of the wastewater and promote biodegradation; a pressure regulating mechanism, the pressure regulating mechanism cooperates with the gas supply mechanism.

[0007] Preferably, the gas supply mechanism includes an L-shaped plate fixedly connected to the right side of the high-pressure box body, a piston cylinder is installed on the left side of the vertical part of the L-shaped plate, a first piston block that can slide left and right is arranged in the piston cylinder, the upper output shaft of the double-shaft motor is fixedly connected with a rotating plate, the rotating plate is in a disc shape, and a connecting rod is rotatably connected to the eccentric part of the upper end of the rotating plate, and the left end of the connecting rod is rotatably connected to the left end of the first piston block.

[0008] Preferably, the right-side space of the piston cylinder communicates with the outside through a one-way port, and the right-side space of the piston cylinder communicates with the inside of the high-pressure box body through a one-way pipe.

[0009] Preferably, one-way valves are installed inside both the one-way port and the one-way pipe. The flow direction of the one-way valve in the one-way port is from the outside to the right-side space of the piston cylinder unidirectionally, and the flow direction of the one-way valve inside the one-way pipe is from the right-side space of the piston cylinder to the inside of the high-pressure box body unidirectionally.

[0010] Preferably, an eddy current pipe is communicated with the inner bottom of the high-pressure box body, a pressure relief valve is installed at the air inlet end of the eddy current pipe, a hot air pipe is communicated with the hot air end of the eddy current pipe, the rotating pipe is a pipe body with a sealed upper end and a conducting lower end, and the lower end of the rotating pipe is communicated with the air outlet end of the hot air pipe through a rotary joint.

[0011] Preferably, a plurality of stirring pipes are fixedly connected to the outer side of the rotating pipe inside the cylinder body, a plurality of the stirring pipes are all communicated with the rotating pipe, a plurality of air holes are opened at the lower ends of the plurality of stirring pipes, one ends of the plurality of stirring pipes away from the rotating pipe are all sealed, a stirring plate is fixedly connected to the upper end of each stirring pipe, and a plurality of bending channels are opened on each stirring plate.

[0012] Preferably, the pressure regulating mechanism includes a pressure regulating cylinder fixedly connected to the upper end of the cylinder body. A piston groove is formed at the lower end of the pressure regulating cylinder, and the lower end of the piston groove extends into the cylinder body. The inner top of the piston groove communicates with the outside through a through port. A second piston block that can slide up and down is arranged in the piston groove, and the upper end of the second piston block is elastically connected to the inner top of the piston groove through a spring.

[0013] Preferably, an installation block is fixedly connected to the inner top of the piston groove, and a touch delay switch is installed at the lower end of the installation block. An air discharge pipe is communicated with the inner top of the cylinder body, and an electromagnetic valve is installed inside the air discharge pipe. The electromagnetic valve is electrically connected to the touch delay switch.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] 1. The waste water is heated to the optimal active temperature of Bacillus stearothermophilus by the annular electric heating plate. With the use of the stirring structure, the internal temperature and the uniformity of the microbial concentration are stronger, effectively improving the degradation ability of the microorganisms and ensuring that the biochemical reaction in the waste water treatment process is in the optimal state.

[0016] 2. Oxygen supply is realized by the intermittent injection of high-pressure gas, meeting the oxygen demand of Bacillus stearothermophilus. At the same time, based on the principle that hot air is released from the hot end of the vortex tube, the waste water temperature will not be reduced due to heat exchange, ensuring that the water body temperature is always within the appropriate range.

[0017] 3. By using the pressure regulating mechanism, the air pressure inside the cylinder body changes reciprocally between large and small. In the high-pressure state, the bubbles floating in the water are smaller, and when it suddenly becomes a low-pressure state, the floating bubbles will rapidly expand and burst, so that the oxygen in the bubbles is dissolved in the water to a higher degree.

[0018] 4. The inside of the cylinder body is always in a state higher than the normal air pressure. Under the high-pressure state, it is more conducive to the dissolution of oxygen in the water body, promoting the progress of dissolved oxygen, ensuring the oxygen demand of Bacillus stearothermophilus, and under the high-pressure state, the overall actual size of the bubbles is smaller than that under the normal air pressure. According to Stokes' law, the smaller the bubble, the smaller its floating speed and the longer its residence time in the water body, increasing the possibility of bursting in the water body, and thus increasing the dissolved oxygen rate.

[0019] 5. During the rotation of the rotating pipe, both the stirring pipe and the stirring plate will rotate. The rotation of the stirring pipe will make the bubbles discharged from the air holes cover the wastewater more evenly, while the rotation of the stirring plate will make a part of the floating bubbles pass through the curved channel. After passing through the curved channel with the wastewater, this part of the bubbles will move obliquely downward. By using this method, the overall path of the floating bubbles can be changed, so that they stay in the water body for a longer time. And because of the flowing of the inclined water body, the bubbles will also deform in the inclined direction, making their upward movement resistance greater and staying in the water body for a longer time.

[0020] In summary, the wastewater treatment device uses biological treatment to completely remove the dispersant in the wastewater, ensuring the pulp recovery rate. And during the biological treatment process, the biological bacteria are in a more suitable environment, ensuring the efficiency of biological treatment. Brief Description of the Drawings

[0021] Figure 1 is a schematic structural diagram of a papermaking wastewater treatment device for improving the pulp recovery rate proposed by the present invention;

[0022] Figure 2 is Figure 1 the sectional structural diagram;

[0023] Figure 3 is Figure 2 the front structural diagram;

[0024] Figure 4 is the schematic structural diagram of the gas supply mechanism;

[0025] Figure 5 is the sectional view of the cooperation between the double-shaft motor and the piston cylinder;

[0026] Figure 6 is the sectional view of the connection between one stirring pipe and the rotating plate;

[0027] Figure 7 is Figure 6 the left structural diagram.

[0028] In the figure: 1 cylinder body, 2 support seat, 3 feeding port, 4 pressure regulating cylinder, 5 through port, 6 air release pipe, 7 solenoid valve, 8 high-pressure box body, 9 double-shaft motor, 10 L-shaped plate, 11 one-way pipe, 12 hot air pipe, 13 annular electric heating plate, 14 spring, 15 second piston block, 16 rotating pipe, 17 stirring shaft, 18 stirring pipe, 19 rotary joint, 20 synchronous pulley, 21 synchronous belt, 22 mounting block, 23 touch delay switch, 24 rotating plate, 25 piston cylinder, 26 first piston block, 27 connecting rod, 28 one-way port, 29 stirring plate, 30 curved channel, 31 air hole, 32 eddy current pipe, 33 pressure relief valve, 34 piston groove. Detailed Embodiment

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0030] Referring to Figures 1-7 , a papermaking wastewater treatment device for improving the pulp recovery rate, including a cylinder body 1, a support base 2 is installed at the lower end of the cylinder body 1, a plurality of annular electric heating plates 13 are connected to the inner wall of the cylinder body 1, and the wastewater inside the cylinder body 1 can be heated through the annular electric heating plates 13 to facilitate the biological degradation. A feeding port 3 is installed at the upper end of the cylinder body 1. The feeding port 3 adopts a sealable structure and is also installed with a sealing cover as shown in the figure. It should be noted that a pump body structure (not shown) is also installed to pump and discharge the treated wastewater.

[0031] As an embodiment of the present invention, it further includes a stirring mechanism. The stirring mechanism includes a rotating pipe 16 rotatably connected to the inner bottom of the cylinder body 1. A plurality of stirring shafts 17 are fixedly connected to the outside of the rotating pipe 16. The lower end of the rotating pipe 16 extends to the outside. A high-pressure box body 8 is fixedly connected to the right side of the cylinder body 1. The high-pressure box body 8 is filled with high-pressure gas. A double-shaft motor 9 is installed on the right side of the high-pressure box body 8. Synchronous wheels 20 are installed on the lower output shaft of the double-shaft motor 9 and the outside of the rotating pipe 16 respectively. The two synchronous wheels 20 are connected by a synchronous belt 21.

[0032] As an embodiment of the present invention, it further includes a gas supply mechanism for increasing the oxygen content of the wastewater and promoting the biological degradation. The gas supply mechanism includes an L-shaped plate 10 fixedly connected to the right side of the high-pressure box body 8. A piston cylinder 25 is installed on the left side of the vertical part of the L-shaped plate 10. A first piston block 26 that can slide left and right is arranged in the piston cylinder 25. The upper output shaft of the double-shaft motor 9 is fixedly connected with a rotating plate 24. The rotating plate 24 is in a disc shape. An eccentric part at the upper end of the rotating plate 24 is rotatably connected with a connecting rod 27. The left end of the connecting rod 27 is rotatably connected with the left end of the first piston block 26. The right side space of the piston cylinder 25 is communicated with the outside through a one-way port 28. The right side space of the piston cylinder 25 is communicated with the inside of the high-pressure box body 8 through a one-way pipe 11. One-way valves are installed inside both the one-way port 28 and the one-way pipe 11. The flow direction of the one-way valve in the one-way port 28 is from the outside to the right side space of the piston cylinder 25 unidirectionally. Further, an air filter can be installed at the air inlet part of the one-way port 28 to separate and remove impurities and dust in the air. The flow direction of the one-way valve inside the one-way pipe 11 is from the right side space of the piston cylinder 25 to the inside of the high-pressure box body 8 unidirectionally.

[0033] As an embodiment of the present invention, an eddy current tube 32 is connected to the inner bottom of the high-pressure box body 8. The eddy current tube 32 is a prior art. After high-pressure gas is introduced, a low-temperature air flow will be generated at the cold end and a high-temperature air flow will be generated at the hot end. A pressure relief valve 33 is installed inside the air inlet end of the eddy current tube 32. The hot air end of the eddy current tube 32 is connected to a hot air pipe 12. The rotating tube 16 is a tube body with a sealed upper end and a conducting lower end. The lower end of the rotating tube 16 is connected to the air outlet end of the hot air pipe 12 through a rotary joint 19. A plurality of stirring tubes 18 are fixedly connected to the outside of the rotating tube 16 inside the cylinder body 1. The plurality of stirring tubes 18 are all connected to the rotating tube 16. A plurality of air holes 31 are opened at the lower ends of the plurality of stirring tubes 18. One ends of the plurality of stirring tubes 18 away from the rotating tube 16 are all sealed. A stirring plate 29 is fixedly connected to the upper end of each stirring tube 18. A plurality of curved channels 30 are opened on each stirring plate 29. By adopting this method, the rising speed of the air can be effectively reduced;

[0034] As an embodiment of the present invention, it further includes a pressure regulating mechanism. The pressure regulating mechanism cooperates with the gas supply mechanism. The pressure regulating mechanism includes a pressure regulating cylinder 4 fixedly connected to the upper end of the cylinder body 1. A piston groove 34 is opened at the lower end of the pressure regulating cylinder 4. The lower end of the piston groove 34 extends into the cylinder body 1. The inner top of the piston groove 34 is communicated with the outside through a through port 5. A second piston block 15 that can slide up and down is arranged inside the piston groove 34. The upper end of the second piston block 15 is elastically connected to the inner top of the piston groove 34 through a spring 14. An installation block 22 is fixedly connected to the inner top of the piston groove 34. A touch delay switch 23 is installed at the lower end of the installation block 22. An air discharge pipe 6 is connected to the inner top of the cylinder body 1. An electromagnetic valve 7 is installed inside the air discharge pipe 6. The electromagnetic valve 7 is electrically connected to the touch delay switch 23. When the touch delay switch 23 is triggered, the electromagnetic valve 7 will be powered on for 3 seconds and then automatically powered off.

[0035] In the present invention, during specific use, wastewater is put in through the feeding port 3, and then an appropriate amount of Bacillus stearothermophilus is put into the wastewater. Subsequently, the feeding port 3 is sealed, and then the annular electric heating plate 13 is started. The annular electric heating plate 13 can heat the wastewater to about 60 °C to make the activity of Bacillus stearothermophilus in the best state;

[0036] At the same time, the double-shaft motor 9 is started. The start of the double-shaft motor 9 will drive the rotating tube 16 to rotate through the transmission of the synchronous belt 21 and the synchronous pulley 20. The rotation of the rotating tube 16 will cause the plurality of stirring shafts 17 to rotate, so that the water body is stirred, and the Bacillus stearothermophilus inside is dispersed more evenly, and at the same time, the temperature of the water body is more uniform;

[0037] In the above process, the start of the dual-axis motor 9 will also drive the rotation of the rotating plate 24. The rotation of the rotating plate 24 will cause the first piston block 26 to reciprocate left and right through the connecting rod 27. The left and right reciprocating motion of the first piston block 26 will generate a unidirectional gas flow among the outside, the piston cylinder 25, and the high-pressure box 8 through the one-way port 28 and the one-way valve inside the one-way pipe 11. This unidirectional gas flow can inject high-pressure gas into the high-pressure box 8. Since there is already high-pressure gas in the high-pressure box 8 and its air pressure is near the threshold range of the pressure relief valve 33, when gas is injected again, the air pressure will be higher than the threshold of the pressure relief valve 33, so a part of the high-pressure gas will be released. When the gas is released to be lower than the threshold of the pressure relief valve 33, the pressure relief valve 33 closes again. In this way, the pressure relief valve 33 will intermittently release high-pressure gas. The released high-pressure gas passes through the vortex tube 32 and is discharged from the hot end and the cold end. The high-pressure gas discharged from the hot end enters the rotating tube 16 through the hot air pipe 12 and finally is discharged from the multiple air holes 31 of the stirring tube 18. After the discharged high-temperature gas enters the wastewater, the floating bubbles burst in the water, which can increase the dissolved oxygen content in the water body, thus ensuring that Bacillus stearothermophilus is in a highly efficient degradation state. Moreover, the upper bubbles can further promote the water body flow, making the overall temperature and the distribution of Bacillus stearothermophilus more uniform. And since the gas itself is in a high-temperature state, it will not exchange heat to reduce the temperature of the wastewater, ensuring that the water body temperature is always in a suitable state;

[0038] It should be noted that as gas is continuously injected into the cylinder body 1, the air pressure in the top space inside the cylinder body 1 increases, and at the same time, it pushes the second piston block 15 to move upward and compresses the spring 14. When the second piston block 15 moves upward to contact the touch delay switch 23, the solenoid valve 7 is energized for 3 seconds. In this way, the high pressure inside the cylinder body 1 will be quickly released through the air discharge pipe 6. Under the elastic action of the spring 14, the second piston block 15 moves downward. After the solenoid valve 7 closes, the air pressure inside the cylinder body 1 will continue to increase and repeat the above process reciprocally. In the specific use process, by using this method, the air pressure inside the cylinder body 1 becomes larger and smaller reciprocally. In the high-pressure state, the floating bubbles in the water are smaller, and when it suddenly becomes a low-pressure state, the floating bubbles will rapidly expand and burst, so that the oxygen in the bubbles can be dissolved in the water to a higher degree;

[0039] In this process, the inside of the cylinder body 1 is always in a state higher than the normal air pressure. In the high-pressure state, it is more conducive to the dissolution of oxygen in the water body, promoting the progress of dissolved oxygen and ensuring the demand of Bacillus stearothermophilus for oxygen. And in the high-pressure state, the overall actual size of the bubbles is smaller than that under the normal air pressure. According to Stokes' law, the smaller the bubble, the smaller its upward floating speed and the longer its residence time in the water body, increasing the possibility of bursting in the water body, and thus improving the dissolved oxygen rate;

[0040] In addition, it should be noted that during the rotation of the above-mentioned rotating tube 16, both the stirring tube 18 and the stirring plate 29 will rotate. The rotation of the stirring tube 18 will make the bubbles discharged from the air holes 31 cover the wastewater more evenly, while the rotation of the stirring plate 29 will make a part of the floating bubbles pass through the curved channel 30. After passing through the curved channel 30 with the wastewater, this part of the bubbles will move obliquely downward. By using this method, the overall path of the floating of some bubbles can be changed, so that their residence time in the water body is longer. Moreover, due to the flow of the inclined water body, the bubbles will also be deformed in the inclined direction, making the upward movement resistance greater and the residence time in the water body longer.

[0041] Through the above structure, the effect of biological treatment can be ensured, so that the dispersant is completely removed, thereby improving the subsequent pulp recovery rate.

[0042] The above is only the preferred specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered within the protection scope of the present invention.

Claims

1. A papermaking wastewater treatment device for improving the pulp recovery rate, characterized in that, Comprising: A cylinder body (1), a support base (2) is installed at the lower end of the cylinder body (1), a plurality of annular electric heating plates (13) are connected to the inner wall of the cylinder body (1), and a feeding port (3) is installed at the upper end of the cylinder body (1); A stirring mechanism, the stirring mechanism includes a rotating pipe (16) rotatably connected to the inner bottom of the cylinder body (1), a plurality of stirring shafts (17) are fixedly connected to the outer side of the rotating pipe (16), the lower end of the rotating pipe (16) extends to the outside, a high-pressure box body (8) is fixedly connected to the right side of the cylinder body (1), a double-shaft motor (9) is installed on the right side of the high-pressure box body (8), synchronous wheels (20) are installed on the lower output shaft of the double-shaft motor (9) and the outer side of the rotating pipe (16), and the two synchronous wheels (20) are connected by a synchronous belt (21) for transmission connection; A gas supply mechanism, the gas supply mechanism is used to increase the oxygen content of the wastewater and promote biodegradation; A pressure regulating mechanism, the pressure regulating mechanism cooperates with the gas supply mechanism; The pressure regulating mechanism includes a pressure regulating cylinder (4) fixedly connected to the upper end of the cylinder body (1), a piston groove (34) is opened at the lower end of the pressure regulating cylinder (4), the lower end of the piston groove (34) extends into the cylinder body (1), the inner top of the piston groove (34) is communicated with the outside through a through port (5), a second piston block (15) that can slide up and down is arranged in the piston groove (34), and the upper end of the second piston block (15) is elastically connected to the inner top of the piston groove (34) through a spring (14); An installation block (22) is fixedly connected to the inner top of the piston groove (34), a touch delay switch (23) is installed at the lower end of the installation block (22), a discharge pipe (6) is communicated with the inner top of the cylinder body (1), a solenoid valve (7) is installed inside the discharge pipe (6), and the solenoid valve (7) is electrically connected to the touch delay switch (23); As gas is continuously injected into the cylinder body, the air pressure in the upper space of the cylinder body increases, pushing the second piston block upward and compressing the spring. When the second piston block moves upward to contact the touch delay switch, the solenoid valve is energized for 3 seconds, so that the high pressure inside the cylinder body will be quickly released through the discharge pipe; the air pressure inside the cylinder body reciprocally becomes larger and smaller. In the high-pressure state, the bubbles floating in the water are smaller, and when it suddenly becomes a low-pressure state, the floating bubbles will quickly expand and burst, thereby increasing the oxygen dissolution degree in the bubbles.

2. The papermaking wastewater treatment device for improving pulp recovery rate according to claim 1, characterized in that, The gas supply mechanism includes an L-shaped plate (10) fixedly connected to the right side of the high-pressure box body (8), a piston cylinder (25) is installed on the left side of the vertical part of the L-shaped plate (10), a first piston block (26) that can slide left and right is arranged inside the piston cylinder (25), the upper output shaft of the double-shaft motor (9) is fixedly connected to a rotating plate (24), the rotating plate (24) is in a disc shape, a connecting rod (27) is rotatably connected to the eccentric position at the upper end of the rotating plate (24), and the right end of the connecting rod (27) is rotatably connected to the left side of the first piston block (26).

3. The papermaking wastewater treatment device for improving the pulp recovery rate according to claim 2, characterized in that, The right-side space of the piston cylinder (25) communicates with the outside through a one-way port (28), and the right-side space of the piston cylinder (25) communicates with the inside of the high-pressure box body (8) through a one-way pipe (11).

4. The papermaking wastewater treatment device for improving the pulp recovery rate according to claim 3, characterized in that, One-way valves are installed inside both the one-way port (28) and the one-way pipe (11). The flow direction of the one-way valve in the one-way port (28) is unidirectional from the outside into the right-side space of the piston cylinder (25), and the flow direction of the one-way valve inside the one-way pipe (11) is unidirectional from the right-side space of the piston cylinder (25) into the inside of the high-pressure box body (8).

5. The papermaking wastewater treatment device for improving pulp recovery rate according to claim 3, characterized in that, An eddy current tube (32) is connected to the inner bottom of the high-pressure box body (8). A pressure relief valve (33) is installed at the air inlet end of the eddy current tube (32). The hot air end of the eddy current tube (32) is connected to a hot air pipe (12). The rotating tube (16) is a tube body with a sealed upper end and a conducting lower end. The lower end of the rotating tube (16) is connected to the air outlet end of the hot air pipe (12) through a rotary joint (19).

6. The papermaking wastewater treatment device for improving the pulp recovery rate according to claim 5, characterized in that, A plurality of stirring tubes (18) are fixedly connected to the outside of the rotating tube (16) inside the cylinder body (1). The plurality of stirring tubes (18) are all connected to the rotating tube (16). A plurality of air holes (31) are opened at the lower ends of the plurality of stirring tubes (18). The ends of the plurality of stirring tubes (18) away from the rotating tube (16) are all sealed. A stirring plate (29) is fixedly connected to the upper end of each stirring tube (18). A plurality of curved channels (30) are opened on each stirring plate (29).

Images