Concentrating and dehydrating machine

Abstract

To provide a concentrating and dehydrating machine capable of obtaining high dehydration while utilizing the basic structure of an existing concentrating and dehydrating machine as it is. [Solution] The system is composed of a notch provided on the tank surface of the raw material storage tank to guide the rotating shaft 21 of the dehydration drum 19B so that it can rotate, a support frame having a bearing 22 that rotatably supports the rotating shaft 21 outside the raw material storage tank and extending in a direction perpendicular to the rotating shaft 21, an air spring 8 provided on one side of the support frame in the extension direction straddling the rotating shaft 21, and a swinging part 7 provided on the other side, and the rotating shaft 21 is displaced left and right in the notch as the air spring 8 expands and contracts. The air spring 8 directly lifts and supports the dehydration drum 19B, and the load applied to the air spring 8 is reduced. When it receives a force in the contracting direction, it contracts, but when the force disappears, it returns to the maximum lifted state, and the raw material mat sent between the trunks 20 is always squeezed under a balanced state of high pressure even if there is a variation in thickness, and is dehydrated to a high concentration in one go.

Description

[Technical field]

[0001] The present invention relates to a concentrating and dewatering machine that can be used for concentrating and dewatering various types of pulp. [Background technology]

[0002] The concentrating dehydrator shown in Patent Document 1 has a raw material inlet at the bottom of a raw material storage tank, a raw material outlet at the top, and two dehydration drums made of a material with water holes such as punched metal and a wire mesh are arranged in parallel inside the raw material storage tank. The two dehydration drums rotate in opposite directions from bottom to top at the tangent line where they come into contact with each other. Furthermore, the dehydration drum on the raw material outlet side rotates in a fixed state at the installed position, and a fine mesh wire mesh is attached to the outer periphery of the dehydration drum. The dehydration drum on the opposite side is tilted with the lower part as a fulcrum by an air spring, and a coarse mesh wire mesh is attached to the outer periphery of the dehydration drum. Both end faces of the two dehydration drums are opened, and the inside of the dehydration drum communicates with a drainage port provided on the side of the raw material storage tank through these openings.

[0003] In this concentrating dehydrator, the raw material, which is composed of water containing about 2-3% stock fiber, is fed into the raw material storage tank from the raw material feed port. As the dehydration drum rotates, the raw material is dehydrated, and the stock fiber is carried upward while being caught by the edge of the hole or the wire mesh, and at the tangent part of the two dehydration drums, the movable dehydration drum is squeezed against the fixed dehydration drum by the action of the air spring described above, so that the raw material is further dehydrated at once, and the stock fiber caught on the movable rotating drum is attracted to the fixed rotating drum and becomes a single plate-like state. This is peeled off by the doctor and transported to the next process. Meanwhile, the water is drained from the drain port.

[0004] This type of concentrator / dehydrator achieves a high degree of dehydration and concentration by filtering and draining the wastewater through the dehydration drum by maintaining water levels inside and outside the drum, and by dehydrating and concentrating the wastewater by squeezing the wire mesh at the points where they meet.It is also cost-effective because it uses a natural vacuum system. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 3433905 Summary of the Invention [Problem to be solved by the invention]

[0006] Recently, there have been efforts to expand the uses of pulp, and it is hoped that special pulps, such as alkaline pulp and non-wood pulps made from sugar cane, will be used as industrial materials. However, for example, the pH of alkaline pulp needs to be lowered to neutral to make it easier to process later. For this reason, the pH is lowered by repeating the cycle of washing → dehydration → washing → dehydration, but it has been found that the pH can be lowered more easily by increasing the degree of dehydration in the dehydration process, and efforts are being made to see if it is possible to dehydrate the material by squeezing the solids content down to 45-50% using alkali. Even if the above-mentioned type of concentrating and dehydrating machine is used, the dehydration rate is currently only 25 to 35%.

[0007] The present invention has been made in consideration of the above-mentioned problems in the conventional technology, and has an object to provide a new and useful concentrating and dehydrating machine that can obtain high dehydration by further evolving the basic configuration of the concentrating and dehydrating machine described in Patent Document 1 while retaining it as it is. [Means for solving the problem]

[0008] The present invention has been made to solve the above problems, and comprises a raw material storage tank to which moisture-containing raw material is supplied, a pair of dehydration drums stored in the raw material storage tank with their bodies arranged side by side in the horizontal direction, a rotating means for rotating the pair of dehydration drums in opposite directions so as to send upward raw material that has risen between the body parts of the pair of dehydration drums from below, a raw material supply port provided in the raw material storage tank and communicating with the lower side of the dehydration drums, a drain port provided in the raw material storage tank and communicating with the inside of the dehydration drums, and a gap between the body part of one dehydration drum and the body part of the other dehydration drum that presses against the raw material that has risen between the body parts while retreating and expanding in an elastically recoverable manner depending on the thickness of the raw material to squeeze it. the compression adjustment means being composed of an insertion guide section provided on the tank surface of the raw material storage tank for rotatably inserting and guiding the rotating shaft of one of the dehydration drums, a support having a bearing for rotatably supporting the rotating shaft outside the raw material storage tank and extending in a direction perpendicular to the rotating shaft, an air spring provided on one side of the support in the extension direction straddling the rotating shaft, and a swinging fulcrum provided on the other side, wherein the rotating shaft can be displaced left and right within the insertion guide section as the air spring expands and contracts, so that the body of the one dehydration drum can retreat elastically and recoverably relative to the body of the other dehydration drum.

[0009] Preferably, the insertion guide portion of the compression adjustment means is configured as a U-shaped notch provided on the vessel surface of the raw material-accommodating vessel and rotatably inserting and guiding the rotation shaft of one of the dehydration drums.

[0010] Preferably, when the support is in a horizontal position, the distance between the trunk of one dewatering drum and the trunk of the other dewatering drum is minimized.

[0011] Preferably, the raw material storage tank has a U-shaped outline when viewed from the axial direction of the pair of dehydration drums, the middle inner bottom surface is flat, and the opposing halves of the pair of dehydration drums are located on the flat surface.

[0012] Preferably, a plurality of raw material supply ports are provided below each of the pair of dehydration drums at intervals in the axial direction of the dehydration drums.

[0013] Preferably, the dehydration drum is constructed of a cylindrical drum made of punched metal with wire mesh stretched over the outer and inner surfaces, the punched metal having a thickness of 12 to 16 mm, an opening rate of 35 to 40%, an arrangement pattern of 60 to 45° zigzag, and a complete periphery with no chips. Effect of the Invention

[0014] The concentrating and dehydrating machine of the present invention is an evolved version of the concentrating and dehydrating machine described in Patent Document 1, with a focus on increasing the compression pressure, making it possible to achieve a higher dehydration rate than before. [Brief description of the drawings]

[0015] [Figure 1] 1 is a front view of a concentration dehydrator according to an embodiment of the present invention. [Diagram 2] 2 is a top view and left and right side views of the concentration dehydrator of FIG. 1. [Diagram 3] FIG. 2 is a front view of the concentrating / dehydrating machine in a state where the front tank surface portion is made transparent, which is a front view of FIG. [Figure 4] FIG. 4 is a front view of the closure plate of FIG. 3. [Diagram 5] FIG. 2 is an explanatory diagram of the configuration of a drainage system that communicates with the inside of the dehydration drum in FIG. [Figure 6] 4A and 4B are diagrams illustrating a pair of dehydration drums in a pressurized state and an open state. [Figure 7] 4 is an explanatory diagram of the arrangement pattern of punched holes in the punching metal constituting the body portion. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] A concentration dehydrator 1 according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the directions are defined based on the front, rear, left, right, top and bottom directions of the concentrating and dehydrating machine 1 shown in Fig. 1. However, these directions are for the convenience of explanation, and the present invention is not limited to these directions. As shown in the front view of Fig. 1, a pair of leg frames 3, 3 are connected to the base frame 2 on the left side and a pair of leg frames 4, 4 are connected to the base frame 2 in an upright state with a gap between them in the left-right direction. A support frame 5 is connected to these leg frames 3, 3, 4, 4 in a direction intersecting with the perpendicular direction. The pair of leg frames 3, 3 are taller than the pair of leg frames 4, 4 and extend upward beyond the support frame 5. Another support frame 6 is connected to the upper end of the support frame 5 in a horizontally bridging position.

[0017] The support frame 5 supported by the pair of leg frames 4, 4 has an open top, and a swinging unit 7 is installed on the left side of the swinging unit 7. The swinging unit 7 is composed of a swing shaft 7a and a pair of mounting parts 7b, 7b, and one of the mounting parts 7b is fixed to the support frame 5. An air spring 8 is installed on the right side of the swinging unit 7. The air spring 8 is composed of a rubber bellows 8a and a pair of face plates 8b, 8b, and one of the face plates 8b is fixed to the support frame 5.

[0018] Reference numeral 9 denotes a support frame, which is fixed in a state in which it is lifted and supported from below by the other mounting portion 7b of the oscillating portion 7 and the other face plate 8b of the air spring 8. The support frames 5 and 9 are lined up vertically, with the support frame 5 extending further to the right. A locking piece 10 that protrudes to the right is attached to the right end of the support frame 9. A stopper bracket 11 is attached to the extending portion of the support frame 5. This stopper bracket 11 is provided with a rod-shaped push-up limit stopper 12 that is screwed into a screw hole that penetrates vertically. The stopper bracket 11 wraps around above the locking piece 10 from the right side, and the locking piece 10 is located below the lower end of the push-up limit stopper 12. Since the push-up limit stopper 12 is attached by screwing into the screw hole, the position of the lower end of the push-up limit stopper 12 can be adjusted by screwing it in and out. In this embodiment, the support frame 9 is supported horizontally in the maximum lifted state, and the upper surfaces of the support frame 9 and the left support frame 6 are approximately flush with each other. As shown in Figs. 2 and 3, the frame structure is provided on each of the front and rear sides.

[0019] Reference numeral 13 denotes a raw material storage tank. This raw material storage tank 13 is composed of a combination of metal plates, and the front and rear tank surfaces 14, 14 are symmetrical horizontally long U-shaped, with the outline of the bottom at the center being linear. Therefore, the inner surface of the raw material storage tank 13 is composed of an inner bottom surface 13a that is curved on the left and right ends and flat in the middle, and a rectangular frame-shaped inner side surface 13b, and has a symmetrical shape with respect to the center in the front-to-rear direction. The raw material storage tank 13 is surrounded from the front and rear directions by the above-mentioned frame structure, and is fixed at appropriate points to be supported and elevated.

[0020] 3 and 4, a pair of closing plates 15, 15 are inserted into the raw material storage tank 13. The closing plate 15 has a horizontally long U-shape that is symmetrical to the tank surface 14, and is installed inserted into the raw material storage tank 13 with its plate surface parallel to the tank surface 14, dividing the raw material storage tank 13 in the front-to-rear direction. One closing plate 15 is disposed closer to the front tank surface 14, and the other closing plate 15 is disposed closer to the rear tank surface 14. However, the vertical dimension of the closing plate 15 is shorter than the vertical dimension of the tank surface 14. The tank surface 14 has rectangular cutouts 14a, 14a spaced apart in the left-right direction, and the closure plate 15 also has cutouts 16, 16 that are open upward and spaced apart in the left-right direction. The cutouts 16 are U-shaped, and the lower cutout edge 16a is a semicircular arc. The cutout edges 16b, 16b that are connected to each other on either side of the cutout edge 16a extend parallel to each other in the up-down direction. When viewed from the front-rear direction, the cutouts 16 are located within the cutouts 14a.

[0021] Closing plate 15 is provided with drainage openings 17, 17 each consisting of a horizontally long rectangular through hole spaced apart in the left-right direction. As shown in Fig. 5, a gap is formed between closing plate 15 and tank surface 14, and opening 13c is formed on the lower surface of the gap, which faces raw material-storing tank 13, and opening 13c serves as the outlet for raw material-storing tank 13. Therefore, as shown by the arrow, water in dehydration drum 19 is discharged outside of thickening dehydrator 1. Furthermore, a raw material overflow port 18 is provided on the right side of the raw material storage tank 13. As shown by the dashed line in Fig. 4, the water level of this raw material overflow port 18 is located below the notch 16 formed in the closing plate 15, so that the raw material does not flow from the center side of the raw material storage tank 13 beyond the upper end of the closing plate 15 into the gap between the closing plate 15 and the tank surface 14. The raw material overflowing from the raw material overflow port 18 is circulated back into the raw material storage tank 13. Note that the raw material overflow port 18 is omitted from Fig. 2.

[0022] A pair of dehydration drums 19A, 19B are accommodated in the space partitioned by a pair of closure plates 15, 15 in the raw material storage tank 13 configured as described above. The dehydration drums 19A and 19B have approximately the same size and shape, and will be referred to as dehydration drum 19 when there is no need to distinguish between them. The body 20 of this dehydration drum 19 is cylindrical. The dehydration drum 19A is accommodated on the left side of the raw material storage tank 13, and the dehydration drum 19B is accommodated on the right side. The body parts 20, 20 are arranged side by side in the horizontal direction, and the rotation shafts 21 extending in the axial direction of each are perpendicular to the tank surface portion 14. Raw material overflow port 18 is provided on the dehydration drum 19B side, which is the pressurized side.

[0023] Bearings 22, 22 are mounted and fixed on the support frames 6, 6, respectively. Notches 16, 16 and bearings 22, 22 are located in the axial direction of a rotating shaft 21 connected to the body 20 of the dehydration drum 19A, and the rotating shaft 21 passes through these notches 16, 16 and extends outward in the front-to-rear direction, with the extended portions being rotatably supported by the bearings 22, 22, respectively. Bearings 22, 22 are also installed and fixed on the support frames 9, 9, and in a similar configuration, notches 16, 16 and bearings 22, 22 are positioned in the axial direction of a rotating shaft 21 connected to the body 20 of the dehydration drum 19B, and the rotating shaft 21 passes through these notches 16, 16 and extends outward in the fore-and-aft direction, with the extending portions being rotatably supported by the bearings 22, 22, respectively. The distance between the opposing cutting edges 16b of the notch 16 is set to be larger than the diameter of the rotating shaft 21, and the rotating shaft 21 can be displaced left and right and up and down within the range surrounded by the cutting edges 16a, 16b, 16b of the notch 16. However, the width dimension (= the distance between cutting edges 16b) of the notch 16 through which the rotating shaft 21 of the fixed side rotating drum 19A is inserted is 185 mm, and the width dimension of the notch 16 through which the rotating shaft 21 of the oscillating side rotating drum 19B is inserted is 232 mm, so the latter is larger.

[0024] The dehydrating drums 19A and 19B are accommodated in the raw material storage tank 13 in a generally symmetrical arrangement, with the lower left quarter arc of the dehydrating drum 19A positioned similarly and spaced apart on the curved surface on the left side of the tank, and the lower right quarter arc of the dehydrating drum 19B positioned similarly and spaced apart on the curved surface on the right side of the tank. Therefore, the opposing semicircular portions of the body 20 of the dehydrating drum 19A and the body 20 of the dehydrating drum 19B are positioned on the middle plane of the inner bottom surface 13a. A motor is connected to each of the rotating shafts 21, 21 of the dehydration drums 19A, 19B, so that the dehydration drums 19A and 19B are rotated around their axes in opposite directions by the motor drive.

[0025] The dehydration drum 19 has a body 20 provided at both axial ends with mounting members 26 for fixedly mounting the rotating shaft 21 to the body 20. The mounting members 26 have a boss portion through which the rotating shaft 21 is inserted and a flat flange portion 26a fixed to the body 20, which are connected by a plurality of support bars 26b, 26b, ... extending radially evenly from the outer circumferential surface of the boss portion. The width of the flange surface of the flange portion 26a varies depending on the drum diameter, and is recommended to be set to a maximum of 125 mm when the drum diameter is φ1700 mm, 110 mm when the drum diameter is φ1500 mm, and 47 mm when the drum diameter is φ600 mm. In this embodiment, the width of the flange surface is set to a maximum of 125 mm when the drum diameter is φ1700 mm. In Figs. 1 and 3, the boss portion is hidden by the bearing 22. The slide seal material S is attached to this flange surface with a plastic flat head screw. The slide seal material S can be made of a material with good surface lubricity, such as synthetic rubber such as highly elastic NBR rubber, or polymer resins such as high molecular weight polyethylene, ultra-high molecular weight polyethylene, polyacetal, silicone resin, fluororesin, and PA66 nylon. The sliding seal material S is pressed against and sealed by a closure plate 15 having a bolt-nut structure BN using a bolt and nut as a pressing means, and closes the axial end side of the body part 20. The closure plate 15 is made of SUS (stainless steel) and has a polished surface, and has excellent self-lubricating and sliding properties, so that the sealing properties are ensured even when the body part 20 rotates.

[0026] As described above, the closing plate 15 is formed with the drainage port 17. The drainage port 17 is substantially rectangular in shape, but the edge of the lower side is arcuate and follows the edge of the flange portion 26a of the mounting member 26. As shown in FIG. 5, a passage extending in the vertical direction is formed between the closing plate 15 and the tank surface portion 14, and this passage is connected to the drainage port 17 at the lower side. An opening 13c is formed in the inner bottom surface 13a of the raw material storage tank 13, which is the lower end of this passage. Therefore, all of the filtrate that has flowed into the body portion 20 and is located higher than the flange portion 26a is discharged to the outside. Since the width dimension of the flange surface of the flange portion 26a is set as small as possible, the filtrate hardly accumulates inside the body portion 20 and is immediately discharged to the outside.

[0027] The dehydration drum 19A is fixed in position within the raw material-storing tank 13 because the axial direction of the rotation shaft 21 of the dehydration drum 19A does not move within the raw material-storing tank 13. In other words, the dehydration drum 19A is the fixed side. In contrast, the dehydration drum 19B is the oscillating side, and is supported and lifted by the oscillating part 7 on the left side of the support frame 9 and by the air spring 8 on the right side, and in the middle of the support frame 9, the perpendicular rotating shaft 21 is loosely fitted into the notch 16 and guided. When the right side of support frame 9 is pushed up by the pressure of compressed air from air spring 8, the lower end face of push-up limit stopper 12 comes into contact with engagement piece 10, preventing further pushing up, and at that time the upper surface of support frame 9 becomes flush with the upper surface of support frame 6 and aligned in the left-right direction. In this state, the body 20 of the dehydrating drum 19A and the body 20 of the dehydrating drum 19B face each other in the left-right direction. Furthermore, the tangents extending in the up-down direction on the opposing sides of the body 20 of the dehydrating drum 19A and the body 20 of the dehydrating drum 19B almost coincide with each other. The distance (clearance) between the body 20 of the dehydrating drum 19A and the body 20 of the dehydrating drum 19B is set to obtain the maximum compression pressure applicable to the anticipated raw material, and is set accordingly in this embodiment. In this embodiment, the position of the lower end of the push-up limit stopper 12 is set as described above, but the position of the lower end can be moved in the vertical direction by threading the screw forward and backward, and the rotating shaft 21 can also be displaced within the range of the notch 16, so that the tangent portion on the side of the body 20 of the dehydration drum 19B can be moved left and right to fine-tune the distance (clearance) between the body 20 of the dehydration drum 19A and the body 20 of the dehydration drum 19B.

[0028] Due to the effects of air spring 8 and push-up limit stopper 12, body 20 of dewatering drum 19B is always biased in a direction to maintain a set constant distance (clearance) relative to body 20 of dewatering drum 19A. When body 20 of dehydration drum 19B receives a force in a direction away from body 20 of dehydration drum 19A against the bias, the force is transmitted to air spring 8 via rotating shaft 21, bearing 22, and support frame 9, causing air spring 8 to contract and lower, and accordingly, swinging portion 7 swings, causing body 20 of dehydration drum 19B to move in a direction away from body 20 of dehydration drum 19A, increasing the gap (clearance). Therefore, the tangent portion on the side of dehydration drum 19B shifts to the right.

[0029] However, since the range in which the rotating shaft 21 can move is limited within the range of the notch 16, the above-mentioned positional deviation is contained within that range. Then, when the force resisting the biasing force disappears or weakens, the air spring 8 expands and rises, returning to or approaching its original state. In other words, the gap (clearance) narrows. Figure 6 shows the pressurized state (filled with air and sealed) and the open state (deflated state) of the air spring 8. It is always pressurized during the spin-drying process, but in the open state the air spring 8 is in its most compressed state with the air deflated, resulting in the greatest displacement. In the pressurized state, the air spring 8 does not displace to this extent, but please use this as a reference for the deformed state of displacement. In conventional concentration dehydrators of this type, an air spring lifts half of the raw material storage tank to move one of the dehydration drums. However, as a feature of the present invention, air spring 8 directly lifts dehydration drum 19B, and since the load on air spring 8 is lighter, it is easier to maintain the maximum lifted state of dehydration drum 19B. On the other hand, when a force is applied in the contracting direction, the air spring quickly contracts, but when the force is removed, the air spring quickly returns to the maximum lifted state.

[0030] The body 20 of the dehydration drum 19 is a cylindrical body formed of punching metal, and a mesh wire net is stretched on both the inner and outer circumferential sides. The wire net (upper net) stretched on the outer circumferential side is finer than the wire net (lower net) stretched on the inner circumferential side. Furthermore, the upper net of the body 20 on the dehydration drum 19A side is finer than the upper net of the body 20 on the dehydration drum 19B side. In this embodiment, the lower net is 8 mesh, the upper net of the dehydration drum 19B side is 14 mesh, and the upper net of the dehydration drum 19A side is 20 mesh. However, this setting is not fixed, and can be changed as appropriate depending on the type of raw material, design changes of other parts of the concentration dehydrator 1, etc. For example, the wire net (upper net) may be even finer, such as 20 mesh for the dehydration drum 19B and 30 mesh for the dehydration drum 19A side.

[0031] The thickness of the punched metal is set to 12 to 16 mm. Existing concentrating dehydrators of this type have a thickness of 10 mm, but this concentrating dehydrator 1 is thicker and stronger. When the squeezing pressure, i.e., the applied pressure, is increased, the trunk parts 20, 20 are also subjected to a strong applied pressure and may become easily deformed, but since the thickness has been increased and the strength has been reinforced as described above, the trunk parts can withstand the increased pressure and are prevented from being deformed or damaged. Therefore, since the dehydration drum 19 is directly lifted and supported by the air spring 8, the pressurizing force can be increased, and since the strength of the body 20 of the dehydration drum 19 has been increased, it is less likely to deform, making it possible to increase the squeezing pressure more than before.

[0032] Furthermore, the opening ratio of the punched metal is set to 35 to 40%, the arrangement pattern is staggered at 60 to 45°, and the edges are configured so that no part of the hole edge is exposed, i.e., the edges are configured as complete peripheries without any chipping. As shown in Fig. 7, even if the hole diameter (D) and hole interval (P) are the same, the aperture ratio (%) is significantly different when comparing a 60° staggered arrangement pattern with a square staggered arrangement pattern (= 45° staggered arrangement). The punched metal constituting the body 20 is set in a 60° staggered arrangement (hole diameter (D): 18 mm, hole interval (P): 28 mm, aperture ratio: 37.4%), and this arrangement pattern continues to the axial end. By configuring in such a fixed arrangement pattern, the entire circumferential surface of the body 20, particularly the entire axial length, can be utilized for suction without waste.

[0033] A plurality of raw material supply ports 23 are provided on the flat bottom surface of the raw material storage tank 13. The raw material supply ports 23, 23, 23 on the left side are located under the dehydration drum 19A and are arranged at a certain interval from each other in the front-rear direction. However, the raw material supply ports 23, 23 on both sides in the front-rear direction are close to the tank surface portions 14, 14, respectively. The raw material supply ports 23, 23, 23 on the right side are similarly arranged with respect to the dehydration drum 19B, and a total of six raw material supply ports 23, 23, ... are arranged symmetrically on the left and right. The tip side of the raw material supply pipe extends from the outside in the left-right direction in the tangential direction directly below the dehydration drum 19, and the raw material supply port 23 at the tip opens directly below the dehydration drum 19 and communicates with the raw material storage tank 13. The raw material supply ports 23, 23, ... are connected to a header pipe 24 directly attached to a pump by hoses 25, 25, ..., respectively. The header pipe 24 is connected to a raw material supply passage and communicates with the inside of the raw material storage tank 13 via a raw material supply port 23 .

[0034] As shown in Fig. 3, a doctor 27 and a scraping conveyor 28 are provided on the fixed side, i.e., the dehydration drum 19A side. The scraping conveyor 28 is disposed in a housing 28a, and the front part of the housing 28a is made transparent in Fig. 3.

[0035] The concentrating and dehydrating machine 1 is configured as described above, and the operation from when the raw material is supplied to when it is discharged will be described. The dewatering drum 19A rotates counterclockwise around its axis, and the dewatering drum 19B rotates clockwise around its axis. The air spring 8 is filled with air and sealed, and is extended to a height regulated by the push-up limit stopper 12. As described above, the effect of the air spring 8 causes the body part 20 on the dewatering drum 19B side to always maintain a constant distance (clearance) with respect to the body part 20 on the dewatering drum 19A side. This constant distance (clearance) is set so that the maximum compression pressure is achieved within an allowable range for the raw material mat to be compressed, taking into account the strength of the dewatering drum 19.

[0036] In this state, when the water-containing raw material, for example, a slurry of alkaline pulp, is blown out and supplied from the raw material supply ports 23, 23, ..., it is sucked by natural vacuum toward the body 20 on the dewatering drum 19A side and the body 20 on the dewatering drum 19B side, respectively, and moves toward the boundary between the body parts 20. In the process, the moisture in the raw material flows into the inside of the dewatering drum 19 through the punched holes in the body 20 and is discharged from the drainage port 17. Therefore, the water is naturally filtered out. The raw material mat that does not enter the inside of the dewatering drum 19 is attached and piled up on the wire mesh. This raw material mat is sent upward through the gaps on the opposing sides of the body 20 on the dewatering drum 19A side and the body 20 on the dewatering drum 19B side.

[0037] The raw material mat fed between the body parts 20, 20 is subjected to a force from the body parts 20, 20 pushing it to a certain clearance, but a force acts from the raw material mat side in a direction pushing it back against the body parts 20, 20 according to its thickness, and the pressure tries to balance. Therefore, when the raw material mat becomes thicker, it quickly retreats and the clearance between the body parts 20, 20 widens, and when the raw material mat loses its thickness, the clearance returns to the initial setting or close to it. In other words, any fluctuation in thickness is quickly absorbed. Therefore, even if the thickness of the raw material mat varies, it is always possible to apply a high compression pressure according to the thickness, and the raw material mat is dehydrated to a high concentration in one go. The dewatered raw mat is then transferred to the dewatering drum 19A, where it adheres to the drum as a single plate, rotates about 120 degrees, is peeled off by the doctor 27, and is then crushed into small pieces by the scraping conveyor 28 and transported to the next process. The water that is removed during squeezing is drained through the drain outlet 17.

[0038] In addition, the entire peripheral surface of the body 20 can be utilized for suction without waste, and the raw material supply ports 23, 23, 23 are oriented toward the middle and both ends of the body 20 in the axial direction, respectively, so that the raw material blown out and supplied from the raw material supply port 23 comes into uniform contact with the body 20, particularly over the entire axial length, and is sucked in. Thus, the amount of material squeezed is uniform throughout the axial length, and the material is squeezed and dewatered to the same extent everywhere. Conventionally, there were no punch holes on either end of the axial direction of the body, and there was only one raw material supply port in the center, which resulted in insufficient dehydration on either end of the axial direction of the body. However, the present invention eliminates such inconveniences.

[0039] As described above, improvements from multiple perspectives are effectively combined, and the concentrating and dehydrating machine 1 ensures higher dehydration performance than the existing concentrating and dehydrating machine of Patent Document 1. In the case of alkaline pulp, it has been confirmed that the solid content can be squeezed and dehydrated to 45 to 50% including the alkali.

[0040] In addition, the inner bottom surface 13a of the raw material storage tank 13 is flat except for the left and right ends, and the boundary between the dehydration drums 19A and 19B is also flat, so that the gap between the boundary between the dehydration drums 19A and 19B and the inner bottom surface 13a is wide, and as shown in Fig. 6, when the air spring 8 is opened, the width dimension of the notch 16 is set larger on the dehydration drum 19B side as described above, so that the body 20 of the dehydration drum 19B moves significantly to the right, sufficiently widening the gap with the body 20 of the dehydration drum 19A. This makes it easier to clean the inside of the raw material storage tank 3.

[0041] Although the embodiment of the present invention has been described in detail above, the specific configuration is not limited to this embodiment, and the invention also includes design changes within the scope of the present invention without departing from the gist of the present invention. For example, in this embodiment, the slide seal material S is attached to the annular flange portion on the dewatering drum 19 side, but it may also be attached to the closure plate 15 side. [Explanation of symbols]

[0042] 1... Thickener / dehydrator 2... Base frame 3...Leg frame 4...Leg frame 5...Support frame 6...Support frame 7... Swinging portion 7a... Swinging shaft 7b...Mounting part 8...Air spring 8a…Rubber bellow 8b…Face plate 9... Support frame 10... Locking piece 11...Stopper bracket 12...Lift limit stopper 13...raw material storage tank 13a...inner bottom surface 13b…Inner surface 13c…Opening 14...tank surface part 14a...missing part 15...Closure plate 16...Notch 16a...Cutting edge 16b...Cutting edge 17: Drain outlet 18: Raw material overflow outlet 19A, 19B... Dehydration drum 20... Body 21...rotating shaft 22...bearing 23... Raw material supply port 24... Header pipe 25... Hose 26... Mounting member 26a... flange portion 26b... support beam 27...Doctor 28...Scraper conveyor 28a…Housing S: Slide seal material BN: Bolt and nut structure

Claims

1. a raw material storage tank to which the water-containing raw material is supplied; A pair of dehydration drums are accommodated in the raw material accommodation tank with their bodies arranged side by side in a horizontal direction; a rotating means for rotating the pair of dehydration drums in opposite directions so as to feed the raw material that has risen from below between the drums of the pair of dehydration drums upward; a raw material supply port provided in the raw material storage tank and communicating with a lower side of the dehydration drum; a drain outlet provided in the raw material storage tank and communicating with the inside of the dehydration drum; A squeeze adjusting means is provided for adjusting the gap between the body of one dehydration drum and the body of the other dehydration drum so that the material that has risen between the body parts is pressed against the material, and the material is squeezed while being retreated and expanded in an elastically recoverable manner depending on the thickness of the material, The compression adjustment means is composed of an insertion guide portion provided on the tank surface of the raw material storage tank for rotatably inserting and guiding the rotating shaft of one of the dehydration drums, a support body having a bearing for rotatably supporting the rotating shaft outside the raw material storage tank and extending in a direction perpendicular to the rotating shaft, an air spring provided on one side of the support body in the extension direction straddling the rotating shaft, and a oscillating fulcrum provided on the other side, and the rotation shaft can be shifted left and right within the insertion guide portion as the air spring expands and contracts, thereby allowing the body of the one dehydration drum to retreat elastically and recoverably relative to the body of the other dehydration drum.

2. In the concentrating and dehydrating machine according to claim 1, A concentrating and dehydrating machine characterized in that the insertion guide portion of the compression adjustment means is composed of a U-shaped notch provided on the tank surface of the raw material storage tank and guides the rotation shaft of one of the dehydrating drums so that it can rotate.

3. In the concentrating and dehydrating machine according to claim 2, 1. A concentrating and dehydrating machine, characterized in that, when the support body is in a horizontal position, the distance between the body of one dehydrating drum and the body of the other dehydrating drum is minimized.

4. In the concentrating and dehydrating machine according to claim 3, A concentrating and dehydrating machine characterized in that the raw material storage tank has a U-shaped outline when viewed from the axial direction of a pair of dehydration drums, the middle inner bottom surface is flat, and the opposing halves of the pair of dehydration drums are located on said flat surface.

5. In the concentrating and dehydrating machine according to claim 4, A concentrating and dehydrating machine comprising: a pair of dehydrating drums, each of which has a plurality of raw material supply ports provided below the corresponding one of the pair of dehydrating drums at intervals in the axial direction of the dehydrating drums.

6. In the concentrating and dehydrating machine according to any one of claims 1 to 5, The dehydration drum is made of punched metal and has wire mesh stretched on the outer and inner surfaces of the cylindrical drum. The perforated metal has a thickness of 12 to 16 mm, an opening rate of 35 to 40%, a zigzag arrangement pattern of 60 to 45°, and a complete peripheral edge without any chipping.

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