Thermomechanical pulp system capable of comprehensively utilizing dirty steam
By designing a thermal grinding mechanical slurry system that comprehensively utilizes dirty steam, the problem of improper treatment of dirty steam in the thermal grinding mechanical slurry production line is solved, and effective recovery of heat energy and fibers and improvement of air quality is achieved.
Patent Information
- Application Number
- CN202421339355.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-13
- Publication Date
- 2025-04-15
- Estimated Expiration
- 2034-06-13
AI Technical Summary
When the existing thermal grinding mechanical slurry production line deals with dirty steam and volatile gases, the heat energy recovery is incomplete, resulting in high production energy consumption and poor air quality in the workshop, and it is difficult to deal with unpleasant odors.
A thermal grinding mechanical slurry system that comprehensively utilizes dirty steam is designed, including a steam unit and a steam treatment unit. The steam unit reasonably distributes fresh steam and dirty steam through the steam cylinder and steam pipeline, which is used for heating and pressurization, and promotes the stable operation of the pulping process. The steam treatment unit uses a high concentration separator, sprayer and arc-shaped screen to separate and spray dirty steam multiple times, recover fibers and heat, and purify harmful gases.
Through this system, the heat and fibers in dirty steam can be effectively recovered, the amount of fresh steam can be used, the production costs can be reduced, the air quality in the workshop can be improved, and environmental pollution can be reduced.
Smart Images
Figure CN222758621U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of papermaking pulping equipment, in particular to a hot grinding mechanical pulping system that comprehensively utilizes dirty steam. Background Art
[0002] Thermomechanical pulp is a pulp made by grinding the plant fiber raw materials into pulp using a pressure refiner after the plant fiber raw materials are preheated by steam in a preheating bin, then enter the cooking cylinder for high-temperature and high-pressure steam cooking. During the high-temperature and high-pressure steam cooking and pressure refiner refining process, the high-temperature and high-pressure steam becomes dirty steam; the cellulose, hemicellulose, lignin and resin contained in the plant fiber raw materials generate a lot of heat due to the strong friction during the mutual friction, extrusion, tearing and fine fiberization process. The pressure refiner generates about 0.8 tons of fresh dirty steam per megawatt per hour; some cellulose, hemicellulose, lignin and resin substances are coked, degraded and vitrified, and volatile gases with unpleasant odor are generated; when the pulp ground into fiber leaves the pressure refiner, the dirty steam, volatile gases and pulp are discharged to the spray bin through the discharge port.
[0003] Under the existing production technology conditions, the heat energy of dirty steam is usually recovered by using a jet condenser to generate hot water and a reboiler to generate fresh steam. However, these two methods are not suitable for a thermomechanical pulp production line with a small production scale of a single machine or only in the electric wave valley. The above production line usually uses a spray fan to spray an aqueous solution containing plant essence in the workshop to neutralize the unpleasant odor of volatile gases. This method does not completely recover the heat energy of dirty steam and the unpleasant odor of volatile gases is difficult to handle. The thermomechanical pulp production line usually faces problems such as high production energy consumption, poor air quality in the workshop, and even complaints from residents around the factory about bad odor. Utility Model Content
[0004] In view of the problem of improper dirty steam treatment method of a thermomechanical pulp production line in the prior art solution, the utility model provides a thermomechanical pulp system which comprehensively utilizes the dirty steam.
[0005] The utility model provides the following technical solution: a thermomechanical pulping system for comprehensively utilizing dirty steam, comprising a pulping unit, the pulping unit comprising a preheating bin, a cork screw conveyor, a cooking cylinder, a discharge screw conveyor, a connecting pipe, a feed screw conveyor, a thermorefiner, a blowdown bin and a first pulp pool connected in sequence, and also comprising a steam unit and a steam treatment unit;
[0006] The steam unit comprises a sub-cylinder, the sub-cylinder is connected to the preheating chamber through a first steam pipe, the sub-cylinder is connected to the top end and the bottom end of the cooking cylinder through a second steam pipe and a third steam pipe respectively, and the sub-cylinder is connected to the thermal mill through a fourth steam pipe;
[0007] The top of the cooking cylinder is connected to the first steam pipe through a first exhaust pipe, the top of the cooking cylinder is connected to the steam processing unit through a second exhaust pipe, and the top of the cooking cylinder is connected to the feeding screw conveyor through a pressure balance pipe; the exhaust pipe of the spray bin is connected to the steam processing unit.
[0008] Preferably, the steam treatment unit comprises a high-concentration separator, a sprayer, and an arc screen;
[0009] The exhaust pipe of the spray bin is connected to the high-concentration separator, the slag discharge port of the high-concentration separator is connected to the first pulp pool, and the exhaust port of the high-concentration separator is connected to the sprayer; the top of the cooking cylinder is connected to the sprayer through a second exhaust pipe;
[0010] The sprayer is provided with a discharge port, the discharge port of the sprayer is provided with a first delivery pump, and the first delivery pump is connected to the curved screen;
[0011] The slag discharge port of the curved screen is connected to the second slurry pool, and the liquid discharge port of the curved screen is connected to the water pool. The water pool is provided with a second delivery pump, and the second delivery pump is connected to the high-concentration separator and the spray bin.
[0012] Preferably, the first steam pipe, the second steam pipe, the third steam pipe, the fourth steam pipe, the first exhaust pipe and the second exhaust pipe are all provided with a one-way valve.
[0013] Preferably, the first steam pipe and the first exhaust pipe are both provided with regulating valves, the preheating chamber is provided with a temperature sensor, and the regulating valve and the temperature sensor are both electrically connected to a flow indicating controller.
[0014] Preferably, the second steam pipe and the third steam pipe are both provided with regulating valves, the cooking cylinder is provided with a pressure sensor and a temperature sensor, and the regulating valve, the pressure sensor and the temperature sensor are all electrically connected to a flow indicating controller.
[0015] Preferably, the fourth steam pipe is provided with a regulating valve, the thermal mill is provided with a pressure sensor, and the regulating valve and the pressure sensor are both electrically connected to a pressure indicating controller.
[0016] Preferably, the pressure balance pipe is provided with a regulating valve, the feeding screw conveyor is provided with a pressure sensor, and the regulating valve and the pressure sensor are both electrically connected to a pressure indicating controller.
[0017] Preferably, the bottom end of the cooking cylinder and the preheating bin are both provided with an annular steam inlet pipe, and the annular steam inlet pipe is provided with a plurality of steam inlets evenly arranged along the circumferential direction; the first steam pipe is connected to the annular steam inlet pipe of the preheating bin, and the third steam pipe is connected to the annular steam inlet pipe at the bottom end of the cooking cylinder.
[0018] Preferably, the pressure balance pipe is connected to the feed screw conveyor through a herringbone steam inlet pipe, and two steam delivery ports of the herringbone steam inlet pipe are respectively connected to two sides of the feed screw conveyor.
[0019] The beneficial effects of the utility model are as follows: the steam unit provides fresh steam for heating and pressurizing the pulping unit, and sends a small part of the dirty steam generated by the cooking cylinder to the preheating bin for preliminary treatment, and uses the fresh steam and the dirty steam to respectively adjust the internal pressures of the hot mill and the feed screw conveyor, thereby promoting the stable operation of the pulping process, saving the use of fresh steam, and reducing costs; the steam treatment unit separates and sprays most of the dirty steam for multiple times, recovers the fiber and heat therein, and purifies harmful gases, thereby saving energy consumption and reducing environmental pollution. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 This is a device connection diagram of an embodiment of the utility model.
[0021] Figure 2 A schematic diagram of an embodiment of a herringbone steam inlet pipe.
[0022] Figure 3 A schematic diagram of an embodiment of an annular steam inlet pipe.
[0023] Figure 4 A schematic diagram of an embodiment of a sprayer.
[0024] Figure numerals: 11-preheating bin, 111-annular steam inlet pipe, 12-cork screw conveyor, 13-cooking cylinder, 131-first steam exhaust pipe, 132-second steam exhaust pipe, 133-pressure balance pipe, 134-herringbone steam inlet pipe, 14-discharging screw conveyor, 15-connecting pipe, 16-feeding screw conveyor, 17-thermal mill, 18-spraying bin, 19-first pulp pool, 21-steam sub-cylinder, 211-first steam pipe, 212-second steam pipe, 213-third steam pipe, 214-fourth steam pipe, 22-high-concentration separator, 23-sprayer, 231-atomizer, 232-packing layer, 24-arc screen, 25-second pulp pool, 26-water pool, 31-flow indicating controller, 32-flow indicating controller, 33-pressure indicating controller, 34-pressure indicating controller. DETAILED DESCRIPTION
[0025] The following is a more detailed description of the implementation of the utility model in conjunction with the drawings and the figure marks, so that those skilled in the art can implement it after reading this specification. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not used to limit the utility model.
[0026] The utility model provides Figure 1-4 A thermomechanical pulping system for comprehensively utilizing dirty steam is shown, comprising a pulping unit, a steam unit and a steam treatment unit.
[0027] The pulping unit is used to grind pulp, and includes a preheating bin 11, a cork screw conveyor 12, a cooking cylinder 13, a discharge screw conveyor 14, a connecting pipe 15, a feed screw conveyor 16, a hot mill 17, a spray bin 18 and a first pulp pool 19, which are connected in sequence. The above equipment can refer to the relevant technology. Plant fiber raw materials such as wood chips and bamboo chips enter the preheating bin from the raw material inlet above the preheating bin 11 for preheating, and are sent to the top of the cooking cylinder 13 through the cork screw conveyor 12. After high-temperature and high-pressure cooking in the cooking cylinder 13, they enter the hot mill 17 through the discharge screw conveyor 14, the connecting pipe 15, and the feed screw conveyor 16 to be ground into fibrous pulp, and then enter the spray bin 18 to separate the dirty steam and pulp, and the pulp falls into the first pulp pool 19 under the action of gravity.
[0028] The steam unit provides fresh steam for heating and pressurizing the pulping unit, preliminarily treats part of the dirty steam, and uses fresh steam and dirty steam to adjust the internal pressure of some equipment to promote the stable operation of the pulping process. The steam unit includes a steam cylinder 21, and the steam from the steam source enters the steam cylinder 21 and is then distributed to various equipment in the pulping unit through multiple steam pipes.
[0029] Please refer to Figure 1 , 3, an annular steam inlet pipe 111 is provided at the bottom of the preheating bin 11, and the sub-cylinder 21 is connected to the annular steam inlet pipe 111 through the first steam pipe 211 to provide fresh steam for the preheating bin 11. The annular steam inlet pipe 111 is provided with a plurality of steam inlets evenly arranged in the circumferential direction and connected to the preheating bin 11 to ensure that the steam evenly heats the preheating bin. At the same time, the top of the cooking cylinder 13 is connected to the first steam pipe 211 through the first exhaust pipe 131. Part of the dirty steam generated by the cooking cylinder 13 is mixed with the fresh steam and enters the preheating bin 11 to contact with the raw materials to complete the preheating. The fresh and dirty steam condenses after contacting with the raw materials, thereby realizing the preliminary treatment of part of the dirty steam, saving the amount of fresh steam and reducing the cost. The first steam pipe 211 and the first exhaust pipe 131 are both provided with a one-way valve to prevent backflow. The first steam pipe 211 and the first exhaust steam pipe 131 are both provided with regulating valves, and the preheating chamber 11 is provided with a temperature sensor. The regulating valve and the temperature sensor are both electrically connected to the flow indicating controller 31. The flow indicating controller 31 adjusts the flow of the first steam pipe 211 and the first exhaust steam pipe 131 through the regulating valve according to the temperature data in the preheating chamber fed back by the temperature sensor and the preset temperature value. If the temperature data in the preheating chamber is not within the preset temperature value range, the flow of the first steam pipe 211 and the first exhaust steam pipe 131 is adjusted.
[0030] The sub-cylinder 21 is connected to the top of the cooking cylinder 13 through the second steam pipe 212, and the bottom of the cooking cylinder 13 is provided with an annular steam inlet pipe 111. The sub-cylinder 21 is connected to the annular steam inlet pipe 111 through the third steam pipe 213, and provides fresh steam to the cooking cylinder 13 to perform high-temperature and high-pressure cooking on the plant fiber raw materials, thereby generating dirty steam. The annular steam inlet pipe 111 is provided with a plurality of steam inlets evenly arranged along the circumferential direction and connected to the cooking cylinder 13. The second and third steam pipes are both provided with a one-way valve to prevent steam backflow. The second and third steam pipes are both provided with a regulating valve, and the cooking cylinder 13 is provided with a temperature sensor and a pressure sensor. The regulating valve, the temperature sensor, and the pressure sensor are all electrically connected to the flow indicating controller 32. The flow indicating controller 32 is based on the pressure and temperature data in the cooking cylinder 13 and the preset pressure value and temperature value. If the pressure and temperature data are not within the preset pressure value and temperature value range, the flow of the second and third steam pipes is separately adjusted through the regulating valve. The top of the cooking cylinder 13 is also provided with an anti-backflow device corresponding to the cork screw conveyor 12 to prevent the plant fiber raw materials from being backflowing to the cork screw conveyor 12 under the action of the steam pressure in the cooking cylinder 13. The anti-backflow device can refer to the relevant technology.
[0031] Part of the dirty steam generated by the cooking cylinder 13 enters the preheating chamber 11 through the first exhaust pipe 131, part of it enters the steam treatment unit through the second exhaust pipe 132 connected to the top of the steam to recover heat and purify it, and part of it enters the feeding screw conveyor 16 through the pressure balance pipe 133 connected to the top of the steam to make the pressure of the cooking cylinder 13 and the feeding screw conveyor 16 relatively balanced. Figure 1 The pressure balance pipe 133 is provided with a regulating valve, the pressure balance pipe 133 is provided with a regulating valve, the feed screw conveyor 16 is provided with a pressure sensor, and the regulating valve and the pressure sensor are both electrically connected to the pressure indicating controller 33. The pressure indicating controller 33 is based on the pressure data of the feed screw conveyor 16 and the preset pressure value. If the pressure data of the feed screw conveyor 16 is less than the preset pressure value, the regulating valve is opened to increase the pressure of the feed screw conveyor 16, thereby promoting the feeding of the hot mill 17 and the discharge of the slurry. Please refer to Figure 2 The pressure balance pipe 133 is connected to the feeding screw conveyor 16 through the herringbone steam inlet pipe 134, and the two steam delivery ports of the herringbone steam inlet pipe 134 are respectively connected to the two sides of the feeding screw conveyor 16. Preferably, the second exhaust pipe 132 is also provided with a bypass pipe, and the bypass pipe is provided with a safety valve. When the pressure in the cooking cylinder 13 is too high, the safety valve and the regulating valve on the second exhaust pipe 132 are opened to release the pressure.
[0032] During the refining process of the heat refiner 17, dirty steam is generated. The steam sub-cylinder 21 is connected to the heat refiner 17 through the fourth steam pipe 214. Fresh steam enters the heat refiner 17, generating a certain pressure to promote the pulp mixed with dirty steam to be discharged into the spraying bin 18. Please refer to Figure 1 The fourth steam pipe 214 is provided with a regulating valve and a one-way valve, the heat mill 17 is provided with a pressure sensor, and the regulating valve and the pressure sensor are electrically connected to the pressure indicating controller 34. The pressure indicating controller 34 opens the regulating valve to increase the pressure in the heat mill 17 according to the pressure data in the heat mill 17 and the preset pressure value if the pressure data in the heat mill is less than the preset pressure value.
[0033] After the slurry enters the spraying bin 18, it falls into the first slurry pool 19 under the action of gravity, and the dirty steam enters the steam treatment unit from the exhaust pipe at the top of the spraying bin 18. Figure 1 The steam treatment unit includes a high-concentration separator 22, a sprayer 23, and an arc screen 24. The exhaust pipe of the spray bin 18 is connected to the high-concentration separator 22, the slag discharge port of the high-concentration separator 22 is connected to the first pulp pool 19, and the exhaust port of the high-concentration separator 22 is connected to the sprayer 23. The high-concentration separator 22 can be a cyclone, which is used to separate dirty steam and fibers mixed therein, and the fibers enter the sprayer 23 from the slag discharge port, such as the first pulp pool 19, and the dirty steam enters the sprayer 23 from the exhaust port. The second exhaust pipe 132 is also connected to the sprayer 23.
[0034] The sprayer 23 can refer to the relevant technology. In this embodiment, please refer to Figure 4The top of the sprayer 23 is provided with an atomizer 231, and the bottom of the atomizer 231 is provided with a packing layer 232 composed of one or more of quartz sand, diatomaceous earth, zeolite, alkaline clay, and activated carbon. The top of the atomizer 231 is a discharge port, and the bottom of the packing layer 232 is provided with two steam inlets. The discharge port at the bottom of the sprayer is provided with a first delivery pump, and the first delivery pump is connected to the arc screen 24. The dirty steam from the second exhaust pipe 132 and the high-concentration separator 22 enters from the two steam inlets and passes through the packing layer upward. The low-temperature cooling water enters the atomizer and is atomized and falls into the packing layer. The packing layer absorbs and purifies the harmful gas in the dirty steam. The low-temperature cooling water absorbs the heat in the dirty steam and becomes hot water, which is sent to the arc screen from the first delivery pump at the bottom of the sprayer, and the purified gas is discharged from the discharge port.
[0035] The curved screen 24 performs secondary separation on the hot water. The slag discharge port of the curved screen 24 is connected to the second pulp pool 25, and the liquid discharge port of the curved screen 24 is connected to the water pool 26. The water pool 26 is provided with a second delivery pump, and the second delivery pump is connected to the high-concentration separator 22 and the spray bin 18. The fibers in the hot water are filtered by the curved screen 24 and enter the second pulp pool 25 from the slag discharge port, and the hot water enters the water pool 26 and is delivered to the high-concentration separator 22 and the spray bin 18 by the second delivery pump for use.
[0036] The above are one or more embodiments of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.
Claims
1. A thermomechanical pulping system for comprehensive utilization of dirty steam, comprising a pulping unit, wherein the pulping unit comprises a preheating bin, a cork screw conveyor, a cooking cylinder, a discharge screw conveyor, a connecting pipe, a feed screw conveyor, a heat refiner, a blowdown bin and a first pulp tank connected in sequence, characterized in that: Also included are a steam unit and a steam treatment unit; The steam unit comprises a sub-cylinder, the sub-cylinder is connected to the preheating chamber through a first steam pipe, the sub-cylinder is connected to the top end and the bottom end of the cooking cylinder through a second steam pipe and a third steam pipe respectively, and the sub-cylinder is connected to the thermal mill through a fourth steam pipe; The top of the cooking cylinder is connected to the first steam pipe through a first exhaust pipe, the top of the cooking cylinder is connected to the steam processing unit through a second exhaust pipe, and the top of the cooking cylinder is connected to the feeding screw conveyor through a pressure balance pipe; the exhaust pipe of the spray bin is connected to the steam processing unit.
2. A thermomechanical pulping system for comprehensive utilization of dirty steam according to claim 1, characterized in that: The steam treatment unit includes a high-concentration separator, a sprayer, and an arc screen; The exhaust pipe of the spray bin is connected to the high-concentration separator, the slag discharge port of the high-concentration separator is connected to the first pulp pool, and the exhaust port of the high-concentration separator is connected to the sprayer; the top of the cooking cylinder is connected to the sprayer through a second exhaust pipe; The sprayer is provided with a discharge port, the discharge port of the sprayer is provided with a first delivery pump, and the first delivery pump is connected to the curved screen; The slag discharge port of the curved screen is connected to the second slurry pool, and the liquid discharge port of the curved screen is connected to the water pool. The water pool is provided with a second delivery pump, and the second delivery pump is connected to the high-concentration separator and the spray bin.
3. The thermomechanical pulping system for comprehensive utilization of dirty steam according to claim 1, characterized in that: The first steam pipe, the second steam pipe, the third steam pipe, the fourth steam pipe, the first exhaust steam pipe and the second exhaust steam pipe are all provided with a one-way valve.
4. The thermomechanical pulping system for comprehensive utilization of dirty steam according to claim 1, characterized in that: The first steam pipe and the first exhaust pipe are both provided with regulating valves, the preheating chamber is provided with a temperature sensor, and the regulating valve and the temperature sensor are both electrically connected to a flow indicating controller.
5. The thermomechanical pulping system for comprehensive utilization of dirty steam according to claim 1, characterized in that: The second steam pipe and the third steam pipe are both provided with regulating valves, the cooking cylinder is provided with a pressure sensor and a temperature sensor, and the regulating valve, the pressure sensor and the temperature sensor are all electrically connected to the flow indicating controller.
6. The thermomechanical pulping system for comprehensive utilization of dirty steam according to claim 1, characterized in that: The fourth steam pipe is provided with a regulating valve, and the thermal mill is provided with a pressure sensor. The regulating valve and the pressure sensor are both electrically connected to a pressure indicating controller.
7. The thermomechanical pulping system for comprehensive utilization of dirty steam according to claim 1, characterized in that: The pressure balance pipe is provided with a regulating valve, the feeding screw conveyor is provided with a pressure sensor, and the regulating valve and the pressure sensor are both electrically connected to a pressure indicating controller.
8. The thermomechanical pulping system for comprehensive utilization of dirty steam according to claim 1, characterized in that: The bottom end of the cooking cylinder and the preheating bin are both provided with an annular steam inlet pipe, and the annular steam inlet pipe is provided with a plurality of steam inlets evenly arranged along the circumferential direction; the first steam pipe is connected to the annular steam inlet pipe of the preheating bin, and the third steam pipe is connected to the annular steam inlet pipe at the bottom end of the cooking cylinder.
9. The thermomechanical pulping system for comprehensive utilization of dirty steam according to claim 1, characterized in that: The pressure balance pipe is connected to the feed screw conveyor through a herringbone steam inlet pipe, and two steam delivery ports of the herringbone steam inlet pipe are respectively connected to two sides of the feed screw conveyor.