A pulp press with uniform pulp feeding
By employing a multi-point uniform slurry feeding design and independent flow control, the problem of uneven slurry distribution in traditional pulping machines has been solved, resulting in higher dewatering efficiency, extended equipment life, and reduced energy consumption.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HAINAN GOLDEN HONGYE PAPER CO LTD
- Filing Date
- 2025-09-03
- Publication Date
- 2026-07-03
AI Technical Summary
Traditional pulping machines use a single-point feeding mode, which results in uneven distribution of pulp along the axial direction, leading to poor dewatering effect, increased energy consumption, severe wear of filter screens, and the risk of clogging.
The design employs a multi-point uniform pulp feeding system, combined with independent flow control and vacuum chamber suction, to ensure that the wet pulp layer is evenly distributed along the axial direction. The control unit enables precise control of the pulp flow rate and concentration, and the press rollers rotate at a constant speed for uniform extrusion.
It improves pulp dryness, reduces energy consumption, extends filter life, reduces the risk of clogging, and improves production efficiency.
Smart Images
Figure CN224451249U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of papermaking machinery technology, specifically to a pulp press that provides uniform pulp feeding. Background Technology
[0002] In tissue paper production, short-fiber pulp is transported through pipelines to a two-roll press for dewatering at a concentration of 2.8%-3.1% and a flow rate of 3000-7000 liters / minute. As the core equipment for pulp dewatering, the two-roll press typically has a roll length of 3.5 meters. Traditional presses use a single-point feed mode: the main feed pipe is divided into only two feed branches, with pulp entering from both ends of the feed box. Due to the fluid dynamics characteristics of this design, the pulp cannot spread quickly and evenly along the axial direction of the press rolls, resulting in extremely uneven distribution of the wet pulp layer: near the feed inlet, the pulp accumulates into an extremely thick layer, while further away, the pulp concentration drops sharply, forming a thin layer or even a break in the pulp. Thick pulp areas suffer from insufficient compression, leading to lower dryness, while thin pulp areas also experience low and unstable dryness due to insufficient pressure, resulting in poor overall dewatering. To maintain pulp dryness, it is necessary to increase the linear pressure or decrease the press roll speed, leading to increased energy consumption or reduced production capacity. Furthermore, the filter screen in the thick slurry zone experiences tremendous pressure, which exacerbates local wear and increases the risk of short fiber clogging. Utility Model Content
[0003] To solve the above-mentioned technical problems, this utility model provides a pulping machine with uniform pulp feeding.
[0004] The technical solution of this utility model is as follows: it includes a pulp inlet box, a pulp inlet unit, a discharge unit, and a control unit; the pulp inlet box has two sets of press rollers with opposite directions arranged parallel to each other along its length; a number of pulp inlets are evenly distributed on both sides of the pulp inlet box along its length; the pulp inlet unit includes a main pulp inlet pipe, two branch pulp inlet pipes connected to the main pulp inlet pipe, and a number of branch pulp inlet pipes connected to each branch pulp inlet pipe; each branch pulp inlet pipe is connected to a corresponding pulp inlet, and each branch pulp inlet pipe is equipped with an independent control valve and a flow meter; the control unit is electrically connected to each control valve and flow meter.
[0005] A further technical solution is that the main slurry inlet pipe and each of the slurry inlet branch pipes are also equipped with control valves and flow meters, and all of them are electrically connected to the control unit.
[0006] A further technical solution is that the two sets of press rollers are respectively installed in the feed box through support bearing seats, including a drive roller driven by a motor and a driven roller that rotates in the opposite direction and at the same speed as the drive roller through a transmission structure.
[0007] A further technical solution is that the support bearing seat of the driven roller is connected to the drive output end of a displacement adjustment mechanism. Under the drive of the displacement adjustment mechanism, the driven roller is displaced relative to the driving roller to adjust the pressure zone gap.
[0008] The further technical solution is that the roller surfaces of both sets of press rollers are covered with filter screens, and a vacuum chamber is provided inside the press rollers. In the initial dewatering stage, the free water in the wet pulp layer on the roller surface passes through the filter screen and enters the roller through the suction effect of the vacuum chamber.
[0009] A further technical solution is that the number of slurry inlets on each side of the slurry inlet box is not less than three, and they are evenly distributed along the length of the slurry inlet box.
[0010] A further technical solution is as follows: the discharge unit includes a crushing screw conveyor set on the upper part of two sets of press rolls and a discharge scraper set at the stripping station on the surface of the two press rolls respectively. The discharge scraper is located at the top of the press roll and close to the feed end of the crushing screw conveyor.
[0011] The beneficial technical effects of this invention are as follows: By equidistantly distributed multiple slurry inlets on both sides of the slurry inlet box, combined with a multi-stage pipeline topology, and with each main slurry inlet pipe, each branch slurry inlet pipe, and each branch slurry inlet pipe independently equipped with control valves and flow meters, and controlled in real time by the control unit, the slurry flow rate and concentration along the axial direction of the press roller are synchronously and precisely controlled, ensuring a consistent wet slurry layer thickness and improving the overall dryness of the extruded slurry. Simultaneously, the uniform thickness of the wet slurry layer along the axial direction ensures uniform pressure distribution in the pressing zone, improving extrusion and dewatering efficiency. Furthermore, the optimized pressure distribution in the pressing zone reduces energy consumption; it also avoids localized overload of the filter screen, reducing clogging and extending its service life. Attached Figure Description
[0012] Figure 1 This is a schematic diagram of the overall structure of this utility model;
[0013] Figure 2 This is a schematic diagram of the internal cross-sectional structure of the slurry inlet box of this utility model;
[0014] Figure 3 This is a schematic diagram of the multi-point uniform slurry feeding unit of this utility model;
[0015] Among them: 100, feed box; 200, press roller; 300, crushing screw conveyor;
[0016] 1. Slurry inlet; 2. Main slurry inlet pipe; 3. Branch slurry inlet pipe; 4. Sub-branch slurry inlet pipe; 5. Control valve; 6. Flow meter. Detailed Implementation
[0017] In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, the specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit the scope of this utility model.
[0018] like Figures 1 to 3 As shown, the present invention provides a uniform pulp feed extruder, which includes a pulp feed box 100, a pulp feed unit, a discharge unit, and a control unit; the pulp feed unit includes a plurality of pulp feed ports 1 evenly distributed on both sides of the pulp feed box 100 along the length direction; and two sets of press rollers 200 with opposite directions are arranged parallel to each other along the length direction inside the pulp feed box 100.
[0019] Specifically, both sets of press rollers 200 have filter screens covering their surfaces and are mounted in the feed box 100 via support bearing seats at both ends. Each set includes a drive roller driven by a motor and a driven roller that rotates in the opposite direction and at the same speed as the drive roller via a transmission structure. The driven roller can move relative to the drive roller under the drive of a displacement adjustment mechanism to form an adjustable-gap pressing zone.
[0020] The feeding unit also includes a main feeding pipe 2, which is connected to two branch feeding pipes 3 that supply feeding material to both sides of the feeding box 100. Each branch feeding pipe 3 is equipped with several feed sub-pipes 4, and each feed sub-pipe 4 is connected to a feeding port 1 on the feeding box 100. Each feed sub-pipe 4 is equipped with an independent control valve 5 and a flow meter 6. The main feeding pipe 2 and each feed sub-pipe 3 are also equipped with control valves 5 and flow meters 6. Each control valve 5 and flow meter 6 is electrically connected to a control unit. The control unit drives the control valves 5 according to the real-time flow signals fed back by each flow meter 6 to achieve independent and precise control of the flow rate and velocity of each feeding port 1, ensuring that the slurry can be fed into the feeding box 100 evenly and synchronously along the entire working length of the press roller 200.
[0021] Furthermore, the number of slurry inlets 1 on each side of the slurry inlet box 100 is not less than three, and they are evenly distributed along the length of the slurry inlet box 100.
[0022] Inside the feed tank 100, the press operates through preliminary dewatering and pressing dewatering. During the preliminary dewatering process, the pulp entering from the feed port 1 has its fibers adsorbed and filtered, depositing on the surface of the press rollers 200 to form a wet pulp layer. In this process, the suction effect generated by the vacuum chamber designed inside the press rollers 200, combined with the capillary action of the filter screen, draws free water from the wet pulp layer into the press rollers 200 to achieve preliminary dewatering. As the two sets of press rollers 200 rotate in opposite directions, the wet pulp layer rotates out of the liquid surface and enters the pressing zone between the two press rollers 200. In the pressing zone, the wet pulp layer is subjected to strong mechanical compression, especially the wet pulp layer sandwiched between the two press rollers 200, which is subjected to enormous linear pressure, causing the black liquor in the pulp to be forcefully squeezed out. The squeezed black liquor passes through the filter screen and enters the press rollers 200 before being discharged. The pulp, after pressing dewatering and with significantly improved dryness, leaves the pressing zone as the press rollers 200 rotate.
[0023] The discharge unit includes a crushing screw conveyor 300 disposed on the upper part of two sets of press rollers 200 and a feeding scraper disposed at the stripping station of the roller surface of the two press rollers 200 respectively. The feeding scraper is located at the top of the press roller 200 and close to the feeding end of the crushing screw conveyor 300. The sheet-like or block-like slurry cake formed after the roller surface is stripped by each feeding scraper is broken up by the crushing screw conveyor 300 and conveyed to the next process.
[0024] During the operation of the above extruder, only when the uniformly distributed slurry forms a wet slurry layer with a basically uniform thickness and density on the roller surface of the press roller 200 can the wet slurry layer be subjected to uniform linear pressure along the entire width of the press zone when passing through the press zone, so that the slurry dryness across the entire width is more uniform and higher, and the overall dewatering efficiency is maximized, which is especially suitable for high-concentration or high-hardness slurries.
[0025] Compared to the traditional single-point feeding of pulp in the feed box 100, due to the fluid dynamics within the feed box 100, it is difficult for the pulp to be evenly distributed along the entire axial direction of the press roller 200 in a short time. This results in high pulp concentration and large flow rate near the feed inlet 1, and low pulp concentration and small flow rate further away from the feed inlet 1. In areas with high concentration, the wet pulp layer formed by adsorption on the roller surface is too thick. This excessively thick wet pulp layer is difficult to be fully squeezed in the pressing zone, leading to low pulp dryness in this area. Conversely, in areas with low pulp concentration, the wet pulp layer formed by adsorption on the roller surface is too thin or even discontinuous. This thin wet pulp layer cannot withstand sufficient pressure in the pressing zone, also resulting in low or unstable pulp dryness in this area. Consequently, the overall pulp dryness decreases. To achieve the required pulp dryness, it is necessary to increase the linear pressure or reduce the rotation speed of the press roller 200, which increases energy consumption.
[0026] Furthermore, in areas with high slurry concentration, the filter screen needs to process more slurry and withstand greater friction and pressure, leading to accelerated wear and a shortened lifespan. At the same time, in areas with excessively thick slurry layers, dewatering resistance increases, making it more difficult for black liquor to penetrate the wet slurry layer and filter screen for discharge, increasing the risk of filter screen clogging, especially when the slurry contains a high content of fine fibers or impurities.
[0027] Therefore, this twin-roll pulp press, through its multi-point uniform pulp feeding design along the 200-degree axis of the press rolls and its independent and precise flow control, ensures that the wet pulp layer formed on the roll surface is evenly distributed along the entire width, which greatly improves the pulp drying degree of the pulp press, extends the service life of the filter screen, reduces equipment operating energy consumption, and improves production efficiency.
[0028] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.
Claims
1. A uniform pulp feeding extruder comprising a pulp feeding tank (100), a pulp feeding unit, a discharge unit and a control unit; characterized in that: The feed box (100) has two sets of press rollers (200) arranged parallel to each other along the length direction and with opposite directions. The feed box (100) has several feed ports (1) evenly distributed on both sides along the length direction. The feed unit includes a feed main pipe (2), two feed branch pipes (3) connected to the feed main pipe (2), and several feed branch pipes (4) connected to each feed branch pipe (3). Each feed branch pipe (4) is connected to the corresponding feed port (1), and each feed branch pipe (4) is equipped with an independent control valve (5) and a flow meter (6). The control unit is electrically connected to each control valve (5) and flow meter (6).
2. A uniform pulp feeding extruder according to claim 1, characterized in that: The main slurry inlet pipe (2) and each of the slurry inlet branch pipes (3) are also equipped with control valves (5) and flow meters (6), and are all electrically connected to the control unit.
3. The pulp press for uniform pulp feeding according to claim 1, characterized in that: The two sets of press rollers (200) are respectively installed in the feed box (100) through support bearing seats, including a drive roller driven by a motor and a driven roller that rotates in the opposite direction and at the same speed as the drive roller through a transmission structure.
4. A uniform pulp feeding extruder according to claim 3, characterized in that: The driven roller's support bearing seat is connected to the drive output end of a displacement adjustment mechanism. Under the drive of the displacement adjustment mechanism, the driven roller is displaced relative to the driving roller to adjust the pressure zone gap.
5. A uniform pulp feeding extruder according to claim 1, characterized in that: Both sets of press rolls (200) have their roll surfaces covered with filter screens. The press rolls (200) are equipped with vacuum chambers. During the initial dewatering stage, the free water in the wet slurry layer on the roll surface passes through the filter screen and enters the roll through the suction effect of the vacuum chamber.
6. A uniform pulp feeding extruder according to claim 1, characterized in that: The number of slurry inlets (1) on each side of the slurry inlet box (100) is no less than three, and they are evenly distributed along the length of the slurry inlet box (100).
7. A uniform pulp feeding extruder according to claim 1, characterized in that: The discharge unit includes a crushing screw conveyor (300) disposed on the upper part of two sets of press rolls (200) and a discharge scraper disposed at the stripping station on the roll surface of the two press rolls (200). The discharge scraper is located at the top of the press roll (200) and close to the feed end of the crushing screw conveyor (300).