A branch pulping device and pulping method with adaptive temperature control

Abstract

The invention discloses a self-adaptive temperature-controlled branch pulping device and a pulping method, comprising: a feeding device, a preheating and cooking device, a grinding device and an external heat management device; wherein the external heat management device is used to accurately control the temperature and pressure of the preheating and cooking device and the grinding device, and through a multi-way multi-channel solenoid valve group, any two or more of the water storage tank, heat exchanger, heater, and steam-water separator can form a passage through the multi-way multi-channel solenoid valve group, so that the surplus heat of the grinding device can be recovered, the energy utilization rate can be improved, and the energy consumption in the pulping hot grinding process can be reduced; and the temperature and pressure inside the grinding device can be more accurately controlled, and the quality of the branch hot-grinding pulp can be improved, thereby increasing the proportion of branches used in pulping and improving the economic benefits of pulping.

Description

Technical Field

[0001] The present application relates to the technical field of papermaking, and particularly relates to a branch pulping device with adaptive temperature control and a pulping method. Background Art

[0002] Grey board paper is mainly used for packaging boxes, advertising boards, hardcover books, storage boxes, samples, lining boards, partitions, etc. Grey board paper is an environmentally friendly packaging material made from recycled waste paper, and has the characteristics of uniform and fine paper surface, moderate smoothness, good stiffness, straightness, sufficient thickness, toughness and not easy to deform. Grey board paper is mainly produced from OCC pulp, ONP pulp, wood chip pulp, supplemented with a small amount of slag pulp and sludge. The product classification includes single grey, double grey and full grey, which belongs to an environmentally friendly packaging material and has a high market demand. In the stock preparation process of grey board paper, the wood chip pulp accounts for about 30% of the raw material unit consumption. The main physical indexes of grey board paper, such as the interlayer bonding force, thickness and smoothness, are greatly affected by the quality of the wood chip pulp. In the traditional wood chip pulp preparation process, 75% of fine chips (the main raw material is eucalyptus) are used in combination with 25% of wood chips (branch wood). Although it can meet various usage requirements, due to the shortage of eucalyptus raw materials and the high procurement cost, the production cost of enterprises is increased. In the prior art, if the usage ratio of branch wood is increased, the quality of the obtained wood chip pulp will be affected. Among them, the fiber length of branch wood is shorter, the physical strength of the formed paper is lower, and the wear resistance and tear resistance are poorer. In addition, the holocellulose and pentosan contents of branch wood are lower, while the lignin, ash and extract contents are higher. These differences will also affect the quality of the pulp and the performance of the paper.

[0003] However, the growth cycle of branch wood is short and the regeneration speed is fast, which has obvious advantages in terms of environmental protection and economy. Therefore, how to increase the usage ratio of branch wood in pulping is a technical problem that the industry extremely hopes to break through. Summary of the Invention

[0004] In view of the above problems, the present application provides a branch pulping device with adaptive temperature control, which is used to solve the technical problem of poor branch pulping quality, so as to increase the usage ratio of branch wood in the manufacture of wood chip pulp.

[0005] To achieve the above object, the present application provides a branch pulping device with adaptive temperature control, which is used to thermally grind branch wood into wood chip pulp. The branch pulping device with adaptive temperature control includes: a feeding device, a preheating and cooking device, a grinding device and an external heat management device;

[0006] The feeding device includes a screw conveyor, which is used to convey branch wood slices into the preheating and cooking device; a steam pipe is arranged in the preheating and cooking device, and the steam pipe is used to heat and soften the branch wood slices; the grinding device is used to grind the heated and softened branch wood slices so that the branch wood slices are ground into single fibers;

[0007] The grinding device includes a grinding chamber, a moving grinding disc, a stationary grinding disc, a heat exchanger and a nozzle; the moving grinding disc and the stationary grinding disc are oppositely arranged in the grinding chamber, and the moving grinding disc is driven by a driving motor to rotate and grind relative to the stationary grinding disc; the heat exchanger is used to perform heat exchange with the inside of the grinding chamber to achieve heating or cooling, so that the temperature inside the grinding chamber is within a preset range; the nozzle is used to spray high-pressure steam or hot water into the grinding chamber to heat the branch slices in the grinding chamber and establish the internal pressure of the grinding chamber;

[0008] The external heat management device is used to supply heat to the preheating and cooking device and the grinding device, and control the temperature and pressure in the grinding chamber to be stable within a preset range; the external heat management device includes a water storage tank, a heater, a multi-way multi-pass solenoid valve group and a steam-water separator; the water storage tank, the heat exchanger, the heater, the steam-water separator are connected to the multi-way multi-pass solenoid valve group, and the multi-way multi-pass solenoid valve group controls the conduction or closing of different valve bodies inside it, so that any two or more of the water storage tank, the heat exchanger, the heater, and the steam-water separator can form a passage through the multi-way multi-pass solenoid valve group; the gas output end of the steam-water separator is connected to the steam pipeline and the nozzle; the liquid output end of the steam-water separator is connected to the hot water pipeline and the nozzle; the nozzle is provided with a selection valve, which can select the gas output end to spray high-pressure steam or select the liquid output end to spray hot water;

[0009] When both the temperature and pressure inside the grinding chamber are higher than the preset values, the multi-way multi-pass solenoid valve group connects the output end of the water storage tank to the heat exchanger, so that the low-temperature water in the water storage tank flows into the heat exchanger to cool the heat exchange medium inside the heat exchanger, and preheat the low-temperature water, so that the heat exchanger cools the grinding chamber;

[0010] When the temperature inside the grinding chamber is lower than the preset value but the pressure is higher than the preset value, the multi-way multi-pass solenoid valve group connects the output end of the water storage tank to the heater, and the outflow end of the heater is connected to the heat exchanger. The high-temperature water of the heater flows into the heat exchanger to heat the heat exchange medium inside the heat exchanger, so that the heat exchanger heats the grinding chamber;

[0011] When both the temperature and pressure inside the grinding chamber are lower than the preset values, control the nozzle to select the gas output end to spray high-pressure steam, and the high-temperature water of the heater flows into the heat exchanger to heat the heat exchange medium inside the heat exchanger, so that the heat exchanger heats the grinding chamber.

[0012] Further, the static grinding disc includes a mounting base plate, an inner disc disposed on the surface of the middle part of the mounting base plate, and an outer ring disposed outside the inner disc. A first grinding sheet is disposed on the surface of the inner disc, and a second grinding sheet is disposed on the surface of the outer ring. The first grinding sheet is used for primary crushing, and the second grinding sheet is used for fine grinding;

[0013] The mounting base plate is provided with a first gap adjusting device, and the inner disc is provided with a second gap adjusting device; the second gap adjusting device is used for increasing the gap between the inner disc and the first grinding sheet and the moving grinding disc when the temperature in the grinding cavity is greater than a first preset value; the first gap adjusting device is used for driving the mounting base plate away from the moving grinding disc when the temperature in the grinding cavity is greater than a second preset value, so as to simultaneously increase the gaps between the first grinding sheet and the second grinding sheet and the moving grinding disc, and the second preset value is higher than the first preset value.

[0014] Further, the nozzle includes a first high-pressure nozzle disposed inside the inner disc and used for spraying into the grinding space between the inner disc and the moving grinding disc;

[0015] The first high-pressure nozzle is provided with a booster pump to increase the spraying pressure of the first high-pressure nozzle and increase the internal pressure of the grinding cavity, and the first high-pressure nozzle is connected to the multi-way multi-pass solenoid valve group through a pipeline. When the temperature in the grinding cavity is greater than a third preset value, the multi-way multi-pass solenoid valve group also connects the output end of the water storage tank to the first high-pressure nozzle, so that the first high-pressure nozzle sprays low-temperature water into the grinding space for cooling, and the third preset value is higher than the second preset value.

[0016] Further, the first grinding sheet is a high-chromium cast iron grinding sheet, and the middle part of the first grinding sheet is recessed away from the moving grinding disc to form a conical surface, and the surface of the first grinding sheet is provided with crushing knife marks; the second grinding sheet is a carbon ceramic grinding sheet, and the surface of the second grinding sheet is provided with fine grinding lines.

[0017] Further, the heater is a boiler.

[0018] Further, the preheating and cooking device includes an outer cylinder and an inner cylinder; the inner cylinder is disposed inside the outer cylinder to form a double-layer heat insulation structure, and the steam pipeline extends from the outer cylinder into the inner cylinder for injecting high-pressure steam into the inner cylinder to heat the branch cuttings.

[0019] Further, the preset value of the temperature in the grinding cavity is 155-160 degrees Celsius, and the preset value of the pressure is 6.5-7.5 bar; the temperature of the preheating and cooking device for cooking the branch cuttings is 180-188 degrees Celsius, and the pressure is 8.0-8.8 bar.

[0020] Furthermore, through Bauer screening experiments, the passing rate of the wood chip pulp through a 16-mesh Bauer screen is greater than or equal to 87.5%, the passing rate through a 30-mesh Bauer screen is greater than or equal to 70%, and the passing rate through a 100-mesh Bauer screen is greater than or equal to 39.8%.

[0021] To solve the above technical problems, the present application also provides another technical solution:

[0022] An adaptive temperature-controlled branch pulping method, comprising the following steps:

[0023] Using branch chips as raw materials, wood chip pulp is produced through hot grinding, refining, screening, and concentration. Among them, the hot grinding is to cook and grind the branch chips with the adaptive temperature-controlled branch pulping device described in the above technical solution. Among them, the preset value of the temperature in the grinding chamber of the adaptive temperature-controlled branch pulping device is 155 - 160 degrees Celsius, and the preset value of the pressure is 6.5 - 7.5 bar; the temperature of the cooking of the branch chips by the preheating and cooking device is 180 - 188 degrees Celsius, and the pressure is 8.0 - 8.8 bar.

[0024] Furthermore, the refining includes the steps of:

[0025] After defoaming the wood chip pulp obtained after hot grinding, it is sent to a disc refiner for refining after concentration adjustment, and then refined using a double-disc refiner to cut and dissociate the fibers to meet the pulp requirements.

[0026] Different from the prior art, the above technical solution of the adaptive temperature-controlled branch pulping device is provided with an external heat management device for precisely controlling the temperature and pressure of the preheating and cooking device and the grinding device. On the one hand, through the multi-way multi-pass solenoid valve group, any two or more of the water storage tank, heat exchanger, heater, and steam-water separator can form a passage through the multi-way multi-pass solenoid valve group. Therefore, the surplus heat of the grinding device can be recovered, the energy utilization rate can be improved, and the energy consumption in the hot grinding process of pulping can be reduced; on the other hand, the temperature and pressure inside the grinding device can be controlled more precisely, the quality of the branch hot grinding pulp can be improved, thereby increasing the proportion of branches used in pulping and improving the economic benefits of pulping.

[0027] The above relevant records of the invention content are only an overview of the technical solution of the present application. In order to enable those of ordinary skill in the art to more clearly understand the technical solution of the present application, and then can be implemented according to the content recorded in the text of the specification and the drawings, and in order to make the above objects, other objects, features, and advantages of the present application more easily understood, the following is described in conjunction with the specific embodiments and drawings of the present application. Brief Description of the Drawings

[0028] The accompanying drawings are only used to illustrate the principles, implementation methods, applications, features, effects, etc. of the specific embodiments of the present invention and other related contents, and should not be considered as a limitation to this application.

[0029] In the drawings of the specification:

[0030] Figure 1 It is a schematic structural diagram of the branch pulping device with adaptive temperature control described in the specific embodiment;

[0031] Figure 2 It is a schematic internal structure diagram of the grinding device described in the specific embodiment;

[0032] Figure 3 For Figure 2 The partial enlarged view of part A in

[0033] The descriptions of the reference numerals involved in the above-mentioned respective drawings are as follows:

[0034] 1. Feeding device; 2. Preheating and cooking device; 3. Grinding device; 4. External heat management device;

[0035] 11. Screw conveyor; 12. Coupling; 13. Power mechanism; 21. Cooking chamber;

[0036] 22. Steam pipeline; 23. Feeding port; 24. Discharge auger; 211. Outer cylinder; 212. Inner cylinder;

[0037] 31. Grinding cavity; 32. Driving motor; 33. Discharge mechanism; 34. Feeding pipe;

[0038] 3131. Moving grinding plate; 311. Housing; 312. Sealing strip; 313. Moving grinding disk;

[0039] 314. Static grinding disk; 315. Heat exchanger; 316. Nozzle pipeline; 317. First high-pressure nozzle;

[0040] 318. Nozzle;

[0041] 3141. First gap adjustment device; 3142. Second gap adjustment device; 3143. Inner disk;

[0042] 3144. First grinding plate; 3145. Second grinding plate;

[0043] 41. Multi-way multi-pass solenoid valve group; 42. Heater; 43. Water storage tank; 44. Steam-water separator; Specific embodiment

[0044] To describe in detail the possible application scenarios, technical principles, specific implementable solutions, achievable objectives and effects of this application, etc., the following will be described in detail with reference to the specific examples listed and in conjunction with the accompanying drawings. The embodiments described herein are only used to more clearly illustrate the technical solutions of this application, so they are only examples and cannot be used to limit the protection scope of this application.

[0045] As used herein, the mention of "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment may be included in at least one embodiment of this application. The term "embodiment" that appears in various positions in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or relevance to other embodiments. In principle, in this application, as long as there is no technical contradiction or conflict, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0046] Unless otherwise defined, the meanings of the technical terms used herein are the same as those commonly understood by those skilled in the technical field to which this application belongs; the use of the relevant terms herein is only for describing specific embodiments and is not intended to limit this application.

[0047] In the description of this application, the term "and / or" is an expression used to describe the logical relationship between objects, indicating that three relationships may exist. For example, A and / or B means: there is A, there is B, and there is both A and B at the same time. In addition, the character " / " herein generally represents an "or" logical relationship between the associated objects before and after.

[0048] In this application, terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual quantity, primary or secondary, or order relationship between these entities or operations.

[0049] Without more limitations, in this application, the open-ended expressions such as "including", "comprising", "having" or other similar expressions used in the statement are intended to cover non-exclusive inclusion. These expressions do not exclude that there may be other elements in the process, method or product including the said elements, so that the process, method or product including a series of elements may not only include those defined elements, but also include other elements not explicitly listed, or also include elements inherent to this process, method or product.

[0050] Similar to the understanding in the "Examination Guidelines", in this application, expressions such as "greater than", "less than", "exceeding", etc. are understood not to include the base number; expressions such as "above", "below", "within", etc. are understood to include the base number. In addition, in the description of the embodiments of this application, the meaning of "multiple" is two or more (including two). Similar expressions related to "many", such as "multiple groups", "multiple times", etc., are understood in this way, unless otherwise clearly and specifically defined.

[0051] In the description of the embodiments of this application, the spatially related expressions used, such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "vertical", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the specific embodiment or the drawing, and is only for the convenience of describing the specific embodiment of this application or for the reader to understand, rather than indicating or implying that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, it cannot be understood as a limitation to the embodiments of this application.

[0052] Unless otherwise clearly specified or limited, in the description of the embodiments of this application, the terms "installed", "connected", "connected", "fixed", "set", etc. should be understood in a broad sense. For example, the "connection" can be a fixed connection, a detachable connection, or an integral setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication inside two components or the interaction relationship between two components. For those skilled in the art to which this application belongs, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

[0053] Please refer to Figures 1 to 3 , this embodiment provides a self - adaptive temperature - controlled branch pulping device. The self - adaptive temperature - controlled branch pulping device is used to thermally grind branches into wood chip pulp, that is, only branches are used to make wood chip pulp without using fine chips (the main raw material is eucalyptus), thereby improving the economy of pulping. In this embodiment, the self - adaptive temperature - controlled branch pulping device can accurately control the temperature and pressure inside the thermal grinding device, improve the quality of the wood chip pulp, and thus can use all branches for pulping.

[0054] As Figure 1 shown, in this embodiment, the self - adaptive temperature - controlled branch pulping device includes: a feeding device 1, a pre - heating and cooking device 2, a grinding device 3, and an external thermal management device 4.

[0055] Among them, the feeding device 1 includes a screw conveyor 11. The screw conveyor 11 is used to convey the branch slices into the preheating and cooking device 2. The screw conveyor 11 is connected to the power mechanism 13 through a coupling 12, and the power mechanism 13 drives the screw conveyor 11 to rotate and work.

[0056] A steam pipe 22 is arranged in the preheating and cooking device 2, and the steam pipe 22 is used to heat and soften the branch slices. As Figure 1 shown, the preheating and cooking device 2 includes a cooking chamber 21. The cooking chamber 21 includes an outer cylinder 211 and an inner cylinder 212; the inner cylinder 212 is arranged inside the outer cylinder 211 to form a double-layer heat insulation structure. The steam pipe 22 extends from the outer cylinder 211 into the inner cylinder 212 for injecting high-pressure steam into the inner cylinder 212 to heat the branch slices. A feed inlet 23 is arranged at the upper part of the cooking chamber 21, the feed inlet 23 is connected to the screw conveyor 11, and a discharge auger 24 is arranged at the bottom of the cooking chamber 21. The discharge auger 24 is used to send the heated and softened branch slices into the grinding device 3. The grinding device 3 is used to grind the heated and softened branch slices so that the branch slices are ground into single fibers. The external heat management device 4 is used to supply heat to the preheating and cooking device 2 and the grinding device 3, and to control the temperature and pressure in the grinding chamber 31 to be stable within a preset range.

[0057] As Figure 2 shown, in this embodiment, the grinding device 3 includes a grinding chamber 31, a moving grinding disc 313, a static grinding disc 314, a heat exchanger 315 and a nozzle 318; the housing 311 of the grinding chamber 31 can be composed of two relatively arranged and openable main bodies and covers, and the inside of the main body and the cover encloses to form the grinding chamber 31. In order to ensure the airtightness of the grinding chamber 31, a sealing strip 312 is arranged between the main body and the cover. The grinding device 3 is provided with a feed pipe 34 and a discharge mechanism 33. The branch slices heated and softened by the preheating and cooking device 2 enter the grinding chamber 31 through the feed pipe 34, and the ground slurry is discharged from the grinding chamber 31 by the discharge mechanism 33.

[0058] As Figure 2 shown, the moving grinding disc 313 and the static grinding disc 314 are relatively arranged in the grinding chamber 31, as Figure 1 shown, and the moving grinding disc 313 is driven by a driving motor 32 to rotate and grind relative to the static grinding disc 314, so as to grind the heated and softened branch slices into wood chip pulp. As Figure 2As shown, the heat exchanger 315 is used to perform heat exchange with the interior of the grinding chamber 31 to achieve heating or cooling, so that the temperature inside the grinding chamber 31 is within a preset range. The nozzle 318 is used to inject high-pressure steam or hot water into the grinding chamber 31 to heat the branch cuttings in the grinding chamber 31 and establish the internal pressure of the grinding chamber 31.

[0059] In the prior art, the heat exchanger 315 in the refiner is only used to cool down the interior of the grinding chamber 31, and the heat absorbed by the heat exchanger 315 is discharged to the outside of the refiner in the form of steam. In this embodiment, the connection method and function of the heat exchanger 315 are improved, and the heat exchanger 315 is connected to the external heat management device 4, so that the heat exchanger 315 is not only used to cool down the interior of the grinding chamber 31, but also used to heat it when the temperature inside the grinding chamber 31 is relatively low. Especially in the initial stage of grinding, the internal temperature of the grinding chamber 31 has not risen to the set ideal temperature. By heating it with the heat exchanger 315, the internal temperature of the grinding chamber 31 can be quickly raised to the ideal temperature, thus ensuring the stability of the wood chip pulp quality.

[0060] The external heat management device 4 includes a water storage tank 43, a heater 42, a multi-way multi-pass solenoid valve group 41, and a steam-water separator 44. The water storage tank 43, the heat exchanger 315, the heater 42, and the steam-water separator 44 are connected to the multi-way multi-pass solenoid valve group 41. The multi-way multi-pass solenoid valve group 41 controls the opening or closing of different valve bodies inside it, so that any two or more of the water storage tank 43, the heat exchanger 315, the heater 42, and the steam-water separator 44 can form a passage through the multi-way multi-pass solenoid valve group 41; the gas output end of the steam-water separator 44 is connected to the steam pipeline 22 and the nozzle 318. The liquid output end of the steam-water separator is connected to the hot water pipeline and the nozzle 318; the nozzle is provided with a selection valve, which can select the gas output end to spray high-pressure steam or select the liquid output end to spray hot water. Among them, the nozzle can be arranged on the inner wall of the grinding chamber 31, and the heater can be a boiler. Or the heater is a combination of a boiler and other heating devices such as a heat pump type heater. The hot water pipeline can be used to provide hot water for the production workshop and the like.

[0061] Specifically, when both the internal temperature and pressure of the grinding chamber 31 are higher than the preset values, the multi-way multi-pass solenoid valve group connects the output end of the water storage tank to the heat exchanger 315, allowing the low-temperature water in the water storage tank to flow into the heat exchanger 315 to cool the heat transfer medium inside the heat exchanger 315 and preheat the low-temperature water, so that the heat exchanger 315 cools the grinding chamber 31. When the internal temperature of the grinding chamber 31 is lower than the preset value but the pressure is higher than the preset value, the multi-way multi-pass solenoid valve group connects the output end of the water storage tank to the heater, and the outlet end of the heater is connected to the heat exchanger 315. The high-temperature water from the heater flows into the heat exchanger 315 to heat the heat transfer medium inside the heat exchanger 315, so that the heat exchanger 315 heats the grinding chamber 31. When both the internal temperature and pressure of the grinding chamber 31 are lower than the preset values, the gas output end of the nozzle is controlled to jet high-pressure steam, and the multi-way multi-pass solenoid valve group connects the output end of the water storage tank to the heater, and the outlet end of the heater is connected to the heat exchanger. The high-temperature water from the heater flows into the heat exchanger to heat the heat transfer medium inside the heat exchanger, so that the heat exchanger 315 heats the grinding chamber 31.

[0062] In this embodiment, the adaptive temperature-controlled branch pulping device is provided with an external heat management device 4 for precisely controlling the temperature and pressure of the preheating and cooking device 2 and the grinding device 3. On the one hand, through the multi-way multi-pass solenoid valve group, any two or more of the water storage tank, heat exchanger, heater, and steam-water separator can form a passage through the multi-way multi-pass solenoid valve group. Therefore, the surplus heat of the grinding device 3 can be recovered, the energy utilization rate can be improved, and the energy consumption in the pulping hot grinding process can be reduced. On the other hand, the temperature and pressure inside the grinding device 3 can be controlled more precisely, the quality of the branch hot grinding into pulp can be improved, so as to increase the use ratio of branches in pulping and improve the economic benefits of pulping.

[0063] Specifically, the preset value of the temperature in the grinding chamber 31 is 155 - 160 degrees Celsius, and the preset value of the pressure is 6.5 - 7.5 bar; the temperature of the cooking of the branches by the preheating and cooking device 2 is 180 - 188 degrees Celsius, and the pressure is 8.0 - 8.8 bar.

[0064] As shown in Table 1 below, it is a comparison of fiber analysis data under different grinding temperatures and pressures;

[0065] Cooking temperature °C 177 181 185 188 Cooking pressure bar 7.7 8.0 8.5 8.8 Fiber length (arithmetic mean) mm 0.64 0.64 0.64 0.63 Fiber length (length weighted) mm 0.88 0.88 0.88 0.87 Fiber length (weight weighted) mm 1.15 1.15 1.15 1.15 Class A fines % 62.93 64.78 65.58 67.84 Class B fines % 1.32 0.69 1.00 1.15 Fines % 90.25 92.11 92.84 94.60 Fiber width µm 24.28 24.15 23.75 23.58 Crimp % 4.45 4.19 4.79 5.01 Kink l / m 2081.8 2025.3 1848.01 1958.2 Degree of fibrillation % 1.11 1.0 0.8 1.17

[0066] Table 1

[0067] Judging from the experimental data, as the grinding temperature and pressure increase, the content of fine fibers increases and the fiber width becomes smaller.

[0068] As shown in Table 2 below, it is a comparison of the Bauer screening data of wood chips under different grinding temperatures and pressures;

[0069]

[0070] Table 2

[0071] After the Bauer screening experiment, the passing rate of the wood chip pulp through a 16-mesh Bauer sieve is greater than or equal to 87.5%, the passing rate through a 30-mesh Bauer sieve is greater than or equal to 70%, and the passing rate through a 100-mesh Bauer sieve is greater than or equal to 39.8%.

[0072] As Figure 2 shown, in this embodiment, the static grinding disc 314 includes a mounting base plate, an inner disc 3143 disposed on the surface of the middle part of the mounting base plate, and an outer ring disposed outside the inner disc 3143. The surface of the inner disc 3143 is provided with a first grinding sheet 3144, and the surface of the outer ring is provided with a second grinding sheet 3145. The first grinding sheet 3144 is used for preliminary crushing, and the second grinding sheet 3145 is used for fine grinding.

[0073] The mounting base plate is provided with a first gap adjusting device 3141, and the inner disc 3143 is provided with a second gap adjusting device 3142; the second gap adjusting device 3142 is used to increase the gap between the inner disc 3143 and the first grinding sheet 3144 and the moving grinding disc 313 when the temperature in the grinding chamber 31 is greater than a first preset value; the first gap adjusting device 3141 is used to drive the mounting base plate away from the moving grinding disc 313 when the temperature in the grinding chamber 31 is greater than a second preset value, so as to increase the gap between the first grinding sheet 3144 and the second grinding sheet 3145 and the moving grinding disc 313 at the same time, and the second preset value is higher than the first preset value.

[0074] Moreover, the nozzle includes a first high-pressure nozzle 317 disposed inside the inner disc 3143 for spraying into the grinding space between the inner disc 3143 and the grinding disc. The inside of the static grinding disc 314 is hollowed out to form a nozzle pipeline 316 communicating with the nozzle.

[0075] The first high-pressure nozzle 317 is provided with a booster pump to increase the spraying pressure of the first high-pressure nozzle 317 and increase the internal pressure of the grinding chamber 31, and the first high-pressure nozzle 317 is connected to the multi-way multi-pass solenoid valve group through a pipeline, that is, the first high-pressure nozzle is communicatively connected to the water storage tank through the multi-way multi-pass solenoid valve group. When the temperature in the grinding chamber 31 is greater than a third preset value, the multi-way multi-pass solenoid valve group also connects the output end of the water storage tank to the first high-pressure nozzle 317, so that the first high-pressure nozzle 317 sprays low-temperature water into the grinding space for cooling, and the third preset value is higher than the second preset value.

[0076] Among them, both the first gap adjusting device 3141 and the second gap adjusting device 3142 are high-precision hydraulic cylinders. The high-precision hydraulic cylinders adopt a servo control system, and a high-precision ball screw is driven by a servo motor to perform pressure assembly operations. The pressure is directly converted from the torque output of the servo motor. Therefore, precise displacement stop, precise in-place stop, etc. can be achieved, and the gaps between the first grinding plate 3144 and the second grinding plate 3145 and the moving grinding disk 313 can be precisely controlled.

[0077] In this embodiment, not only the internal temperature of the grinding chamber 31 is controlled by the above heat exchanger 315, but also the structure of the static grinding disk 314 is improved. The distances between the inner disk 3143 and the outer ring of the static grinding disk 314 and the moving grinding disk 313 can be adjusted, and the distance between the inner disk 3143 and the moving grinding disk 313 can be adjusted independently. In addition, nozzles are provided on the inner disk 3143. Therefore, while ensuring the grinding effect, the internal temperature of the grinding chamber 31 can be controlled more precisely. In this embodiment, the first preset value, the second preset value, and the third preset value of the temperature can be 165°, 170°, and 180° respectively. In other embodiments, the above third preset value can be appropriately adjusted according to actual situations.

[0078] In the above embodiment, the first grinding plate 3144 is a high-chromium cast iron grinding plate. As Figure 3 shown, the middle part of the first grinding plate 3144 is recessed away from the moving grinding disk to form a conical surface, and crushing knife marks are provided on the surface of the first grinding plate 3144; the second grinding plate 3145 is a carbon ceramic grinding plate, and fine grinding lines are provided on the surface of the second grinding plate 3145. The crushing knife marks protrude from the surface of the first grinding plate, and the size is larger than that of the fine grinding lines. In this embodiment, the second grinding plate 3145 is a grinding plate with a flat surface, that is, the second grinding plate 3145 is parallel to the moving grinding plate 3131 on the surface of the moving grinding disk 313. Therefore, the grinding accuracy of the wood chip pulp can be ensured. The middle part of the first grinding plate 3144 is a conical surface and is matched with the second gap adjusting device 3142. Therefore, the crushing (i.e., primary grinding) efficiency during grinding can be better adjusted, and the heat generation during crushing can be better controlled.

[0079] Another embodiment of the present application provides a self-adaptive temperature-controlled branch pulp making method. The self-adaptive temperature-controlled branch pulp making method includes the following steps:

[0080] Using branch chips as raw materials, wood chips pulp is produced through hot grinding, refining, screening and concentration. Among them, the hot grinding is to cook and grind the branch chips by using the self-adaptive temperature-controlled branch pulping device described in the above embodiments. Among them, the preset value of the temperature in the grinding chamber of the self-adaptive temperature-controlled branch pulping device is 155-160 °C, and the preset value of the pressure is 6.5-7.5 bar; the temperature of cooking the branch chips by the preheating and cooking device is 180-188 °C, and the pressure is 8.0-8.8 bar.

[0081] In the above embodiment, the refining includes the steps of:

[0082] After defoaming the wood chips pulp obtained after hot grinding, it is sent to a disc refiner for refining after concentration adjustment, and then a double-disc refiner is used for refining to cut and dissociate the fibers to meet the requirements of the finished pulp.

[0083] The self-adaptive temperature-controlled branch pulping method of this embodiment can produce wood chips pulp only using branch chips without using refined chips (the main raw material is eucalyptus), and can reduce the energy consumption during the hot grinding of branch chips, ensure the quality of the obtained wood chips pulp, and improve the economic benefits of pulping.

[0084] Finally, it should be noted that although the above embodiments have been described in the text and drawings of the specification of this application, the patent protection scope of this application cannot be limited thereby. Any technical solutions obtained by equivalent structure or equivalent process substitution or modification based on the substantial concept of this application and using the content recorded in the text and drawings of the specification of this application, as well as directly or indirectly implementing the technical solutions of the above embodiments in other related technical fields, etc., are all included in the patent protection scope of this application.

Claims

1. An adaptive temperature-controlled branch pulping device for hot grinding branches into sawdust pulp, characterized in that: The adaptive temperature-controlled branch pulping device comprises: a feeding device, a preheating and cooking device, a grinding device and an external heat management device; The feeding device includes a screw conveyor for conveying the branch slices to the preheating and cooking device; the preheating and cooking device is provided with a steam pipeline for heating and softening the branch slices; the grinding device is used to grind the heated and softened branch slices to grind the branch slices into single fibers; The grinding device comprises a grinding chamber, a moving grinding disc, a static grinding disc, a heat exchanger and a nozzle; the moving grinding disc and the static grinding disc are arranged opposite to each other in the grinding chamber, and the moving grinding disc is driven by a driving motor to rotate and grind relative to the static grinding disc; the heat exchanger is used to perform heat exchange with the inside of the grinding chamber to achieve heating or cooling, so that the temperature inside the grinding chamber is within a preset range; the nozzle is used to spray high-pressure steam or hot water into the grinding chamber to heat the branch slices in the grinding chamber and establish the internal pressure of the grinding chamber; The external heat management device is used to supply heat to the preheating and cooking device and the grinding device, and to control the temperature and pressure in the grinding chamber to be stable within a preset range; the external heat management device includes a water storage tank, a heater, a multi-way multi-pass electromagnetic valve group and a steam-water separator; the water storage tank, the heat exchanger, the heater, and the steam-water separator are connected to the multi-way multi-pass electromagnetic valve group, and the multi-way multi-pass electromagnetic valve group controls different valve bodies inside it to be turned on or off, so that any two or more of the water storage tank, the heat exchanger, the heater, and the steam-water separator can form a passage through the multi-way multi-pass electromagnetic valve group; the gas output end of the steam-water separator is connected to the steam pipe and the nozzle; the liquid output end of the steam-water separator is connected to the hot water pipe and the nozzle; the nozzle is provided with a selection valve, which can select the gas output end to spray high-pressure steam or the liquid output end to spray hot water; When the temperature and pressure inside the grinding chamber are higher than the preset values, the multi-way multi-port solenoid valve group connects the output end of the water storage tank with the heat exchanger, so that the low-temperature water in the water storage tank flows into the heat exchanger to cool the heat exchange medium inside the heat exchanger, and preheats the low-temperature water so that the heat exchanger cools the grinding chamber; When the temperature inside the grinding chamber is lower than a preset value but the pressure is higher than a preset value, the multi-way multi-port solenoid valve group connects the output end of the water storage tank to the heater, and the outflow end of the heater connects to the heat exchanger, and the high-temperature water of the heater flows into the heat exchanger to heat the heat exchange medium inside the heat exchanger, so that the heat exchanger heats the grinding chamber; When the temperature and pressure inside the grinding chamber are lower than preset values, the nozzle is controlled to select the gas output end to spray high-pressure steam, and the heat exchanger is used to heat the grinding chamber in the above manner; The preset value of the temperature in the grinding chamber is 155-160 degrees Celsius, and the preset value of the pressure is 6.5-7.5 bar; the temperature of the preheating and steaming device for steaming the branch slices is 180-188 degrees Celsius, and the pressure is 8.0-8.8 bar.

2. The adaptive temperature-controlled branch pulping device according to claim 1, characterized in that: The static grinding disc comprises a mounting base disc, an inner disc arranged on the surface of the middle part of the mounting base disc, and an outer ring arranged on the outer side of the inner disc, the surface of the inner disc is provided with a first grinding sheet, the surface of the outer ring is provided with a second grinding sheet, the first grinding sheet is used for preliminary crushing, and the second grinding sheet is used for fine grinding; The mounting base is provided with a first gap adjustment device, and the inner plate is provided with a second gap adjustment device; the second gap adjustment device is used to increase the gap between the inner plate and the first grinding sheet and the movable grinding plate when the temperature of the grinding chamber is greater than a first preset value; The first gap adjustment device is used to drive the mounting base plate away from the movable grinding plate to simultaneously increase the gaps between the first grinding plate and the second grinding plate and the movable grinding plate when the temperature of the grinding chamber is greater than a second preset value, and the second preset value is higher than the first preset value; The nozzle comprises a first high-pressure nozzle disposed inside the inner disc and used for spraying toward the grinding space between the inner disc and the movable grinding disc; The first high-pressure nozzle is provided with a booster pump to increase the injection pressure of the first high-pressure nozzle and increase the internal pressure of the grinding chamber, and the first high-pressure nozzle is connected to the multi-way multi-port solenoid valve group through a pipeline. When the temperature of the grinding chamber is greater than a third preset value, the multi-way multi-port solenoid valve group also connects the output end of the water storage tank with the first high-pressure nozzle, so that the first high-pressure nozzle sprays low-temperature water into the grinding space for cooling, and the third preset value is higher than the second preset value.

3. The adaptive temperature-controlled branch pulping device according to claim 2, characterized in that: The first grinding sheet is a high-chromium cast iron grinding sheet, and the middle part of the first grinding sheet is concave in the direction away from the movable grinding disc to form a conical surface, and the surface of the first grinding sheet is provided with broken knife lines; the second grinding sheet is a carbon ceramic grinding sheet, and the surface of the second grinding sheet is provided with fine grinding lines.

4. The adaptive temperature-controlled branch pulping device according to claim 1, characterized in that: The heater is a boiler.

5. The adaptive temperature-controlled branch pulping device according to claim 1, characterized in that: The preheating and steaming device comprises an outer cylinder and an inner cylinder; the inner cylinder is arranged inside the outer cylinder to form a double-layer heat-insulating structure, and the steam pipe extends from the outer cylinder into the inner cylinder to inject high-pressure steam into the inner cylinder to heat the branch slices.

6. The adaptive temperature-controlled branch pulping device according to claim 1, characterized in that: According to the ball screening test, the pass rate of the wood chip pulp through the 16-mesh ball screen is greater than or equal to 87.5%, the pass rate through the 30-mesh ball screen is greater than or equal to 70%, and the pass rate through the 100-mesh ball screen is greater than or equal to 39.8%.

7. A method for pulping branches with adaptive temperature control, characterized in that: The following steps are involved: Using branch slices as raw materials, and making sawdust pulp through hot grinding, refining, screening and concentration, wherein the hot grinding is to use the branch pulping device with adaptive temperature control as described in claim 1 to cook and grind the branch slices, wherein the preset value of the temperature in the grinding chamber of the branch pulping device with adaptive temperature control is 155-160 degrees Celsius, and the preset value of the pressure is 6.5-7.5 bar; The preheating and cooking device cooks the branch slices at a temperature of 180-188 degrees Celsius and a pressure of 8.0-8.8 bar.

8. The method for making branch pulp with adaptive temperature control according to claim 7, characterized in that: The seminal plasma comprises the steps of: The sawdust pulp obtained after hot grinding is de-latched, and then sent to a disc refiner for refining after concentration adjustment, and then refined using a double disc refiner to cut and dissociate the fibers to meet the pulping requirements.

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