Roots blower cooling device for quantitative feeding in viscose production

Abstract

A cooling device for a Roots blower used in viscose production for quantitative feeding, relating to the cooling of the Roots blower. An outdoor air inlet duct connects to the air inlet of a surface cooler via the Roots blower. The air outlet of the surface cooler connects to the feeding pipe of a xanthating machine via a star-shaped discharge device. A first switching valve is installed at the air inlet of the outdoor air inlet duct, and a fourth switching valve is installed at the air inlet of the surface cooler. The outdoor air inlet duct connects to an indoor air inlet duct, which is connected before the first switching valve. A second switching valve is installed at the connection between the indoor and outdoor air inlet ducts. The fourth switching valve connects to the air outlet of the surface cooler via a third switching valve. The surface cooler is equipped with a chilled water inlet pipe, a chilled water outlet pipe, and a condensate outlet pipe. This invention can stably control the air supply temperature of the Roots blower at 18-19℃, accurately solving the problem of the impact of hot air generated by gas compression during the operation of the Roots blower on the feed temperature of alkali cellulose. It also has an air inlet switching function, adaptable to different seasonal production needs.

Description

Technical Field

[0001] This utility model relates to the field of viscose fiber manufacturing technology, specifically a cooling device for a Roots blower used for quantitative feeding during the xanthation process of viscose production. Background Technology

[0002] In the traditional viscose fiber production process, each batch of alkali cellulose weighing approximately 2200KG discharged from the cooling drum is conveyed to the weighing machine, and then transported by a Roots blower through the air duct to multiple designated xanthation machines via a conveyor belt and star-shaped discharge device to complete the feeding.

[0003] When the Roots blower is operating, the gas compression continuously generates a large amount of heat, causing the outlet air temperature to remain stable above 40℃. After being conveyed by this hot air, the alkali cellulose enters the xanthation machine at a temperature close to 30℃, while the process requires an initial feed temperature range of 18-19℃, resulting in a temperature difference of 10-12℃. This temperature difference not only makes it difficult for xanthation operators to accurately control the temperature parameters at each stage of the process but also significantly increases the instability of the xanthation process, directly affecting the xanthation reaction efficiency of the alkali cellulose. This leads to fluctuations in key indicators such as viscose viscosity, degree of esterification, filtration value, and maturity, ultimately impacting the quality of subsequent spinning.

[0004] Therefore, it is particularly important to study a Roots blower cooling device for quantitative feeding in adhesive production, in order to solve the problem of excessive feed temperature caused by hot air from the Roots blower and fill the technical gap in temperature control of traditional feeding systems. Summary of the Invention

[0005] To overcome the shortcomings of the existing technology, the purpose of this invention is to provide a Roots blower cooling device for quantitative feeding in viscose production, so as to solve the influence of hot air generated by gas compression during the operation of the Roots blower on the feed temperature of alkali cellulose.

[0006] To achieve the above-mentioned objectives, the outdoor air inlet pipe of the Roots blower cooling device for quantitative feeding in adhesive production is connected to the air inlet of the surface cooler via the Roots blower. The air outlet of the surface cooler is connected to the feeding pipe of the yellowing machine via a pipe and a star-shaped feeder. A first switching valve is provided at the air inlet of the outdoor air inlet pipe, and a fourth switching valve is provided at the air inlet of the surface cooler.

[0007] Furthermore, the outdoor air inlet pipe and the indoor air inlet pipe are connected by a T-junction, the indoor air inlet pipe is installed in front of the first switching valve, and a second switching valve is provided at the connection between the indoor air inlet pipe and the outdoor air inlet pipe.

[0008] Furthermore, the fourth switching valve is connected to the air outlet of the surface cooler via a pipe through the third switching valve.

[0009] Furthermore, the surface cooler is equipped with a chilled water inlet pipe, a chilled water outlet pipe, and a condensate outlet pipe.

[0010] Furthermore, the chilled water inlet pipe and chilled water outlet pipe are located on the same side of the surface cooler, the surface cooler air inlet and air outlet are located on the front and rear sides of the surface cooler respectively, and the condensate outlet pipe is installed at the bottom of the surface cooler.

[0011] Furthermore, a solenoid valve is installed on the condensate outlet pipe.

[0012] Furthermore, the surface cooler is model ZHR115A-0300, the solenoid valve is model 2W250-25 / AC220V-1 normally open type, and the first switching valve, second switching valve, third switching valve, and fourth switching valve are all model PZ573W-10C-DN200 bevel gear knife gate valves.

[0013] During winter and spring / autumn periods of low temperatures, switch to outdoor air intake, drawing air in through the outdoor air inlet. Open the first switching valve and close the second switching valve to allow the Roots blower to draw air directly from the outside. When the exhaust temperature of the Roots blower is too high, close the third switching valve and open the fourth switching valve, directing the airflow through the surface cooler. Simultaneously, increase the flow rate of the chilled water inlet valve on the chilled water inlet pipe to accelerate cooling. When the exhaust temperature of the Roots blower is too low, open the third switching valve and close the fourth switching valve, allowing the airflow to bypass the surface cooler and directly supply air to the xanthate machine's feeding pipe via the star-shaped discharge valve. The cellulose temperature can be reduced to 18-19℃ through the star-shaped discharge valve and the xanthate machine's feeding pipe.

[0014] During the high-temperature periods of summer and spring / autumn, indoor air intake is used. Air is drawn in through the indoor air inlet. The second and fourth switching valves are opened, while the first and third switching valves are closed, allowing the Roots blower to draw air in from indoors. The air is then cooled by chilled water in the surface cooler. Chilled water is added through the chilled water inlet pipe, circulated, and then discharged through the chilled water outlet pipe. After the hot air temperature is reduced, it is then delivered to the xanthate machine's feeding pipe through the star-shaped discharge device. When the Roots blower's exhaust temperature is too high, the chilled water inlet valve on the chilled water inlet pipe can be manually increased to increase the flow rate and accelerate cooling. When the temperature is too low, the chilled water inlet valve on the chilled water inlet pipe can be manually decreased or closed to ensure the temperature of the cellulose entering the xanthate machine is maintained.

[0015] Compared with existing technologies, this invention, by adding a surface cooler to the air supply pipeline and optimizing the air intake method, can stably control the air supply temperature of the Roots blower at 18-19℃ without reconstructing the original feeding system or reducing feeding efficiency. This precisely solves the problem of the hot air generated by gas compression during Roots blower operation affecting the alkali cellulose feed temperature and the issue of excessive feed temperature in the xanthation machine. It ensures temperature stability at each stage of the xanthation process, guarantees that the original feeding equipment is fully adapted to the process temperature control requirements, has low investment costs, reliable operation, and convenient maintenance. It also features an air intake switching function, adapting to production needs in different seasons, and can be widely applied to weighing stations of similar viscose fiber production Roots blowers. Attached Figure Description

[0016] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein:

[0017] Figure 1 This is a simplified diagram of the pipeline structure of the cooling device of this utility model.

[0018] Figure 2 for Figure 1 The structural principle diagram of the surface cooler.

[0019] In the diagram: 1. Outdoor air inlet duct; 2. Indoor air inlet duct; 3. First switching valve; 4. Second switching valve; 5. Roots blower; 6. Third switching valve; 7. Fourth switching valve; 8. Surface cooler; 9. Chilled water inlet pipe; 10. Chilled water outlet pipe; 11. Rotary rotary valve; 12. Yellowing machine feed pipe; 13. Surface cooler air inlet; 14. Surface cooler air outlet; 15. Condensate drain pipe; 16. Solenoid valve. Detailed Implementation

[0020] To make the invention's objectives, technical solutions, and advantages clearer, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the scope of protection of the present invention.

[0021] like Figure 1 , Figure 2 As shown, the outdoor air inlet pipe 1 of the Roots blower cooling device for quantitative feeding in adhesive production is connected to the air inlet 13 of the surface cooler 8 via the Roots blower 5. The air outlet 14 of the surface cooler 8 is connected to the feeding pipe 12 of the yellowing machine via a pipe and a star-shaped feeder 11. A first switching valve 3 is provided at the air inlet of the outdoor air inlet pipe 1, and a fourth switching valve 7 is provided at the air inlet 13 of the surface cooler.

[0022] The outdoor air intake duct 1 and the indoor air intake duct 2 are connected by a T-junction. The indoor air intake duct 2 is installed in front of the first switching valve 3, and a second switching valve 4 is installed at the connection between the indoor air intake duct 2 and the outdoor air intake duct 1. When the temperature is cool (during winter and the low-temperature period of spring and autumn), the second switching valve 4 is closed and the first switching valve 3 is opened, allowing air to enter directly from the outside; when the temperature is hot (during summer and the high-temperature period of spring and autumn), the first switching valve 3 is closed and the second switching valve 4 is opened, switching to indoor air intake.

[0023] The fourth switching valve 7 is connected to the air outlet 14 of the surface cooler via a pipeline through the third switching valve 6. This pipeline is suitable for use when the air temperature is cool and the surface cooler 8 is not used for cooling. The fourth switching valve 7 is closed, the third switching valve 6 is opened, and the air supplied by the Roots blower 5 passes through the third switching valve 6, then through the star-shaped discharge device 11, and is supplied to the xanthating machine feeding pipe 12. When the air temperature is hot and the surface cooler 8 is needed for cooling, the third switching valve 6 is closed, the fourth switching valve 7 is opened, and the air supplied by the Roots blower 5 passes through the fourth switching valve 7, then through the star-shaped discharge device 11, and is supplied to the xanthating machine feeding pipe 12.

[0024] The surface cooler 8 is connected to the outlet duct of the Roots blower 5 via flanges and fittings, using the same diameter and direction as the original feeding duct (same as the outlet duct) to maintain the fluid resistance characteristics of the original feeding system and ensure that the feeding efficiency is not affected. The surface cooler 8 is equipped with a chilled water inlet pipe 9, a chilled water outlet pipe 10, and a condensate drain pipe 15; the chilled water inlet pipe 9 and the chilled water outlet pipe 10 are located on the same side of the surface cooler 8, the surface cooler air inlet 13 and the surface cooler air outlet 14 are located on the front and rear sides of the surface cooler 8, respectively, and the condensate drain pipe 15 is installed at the bottom of the surface cooler 8; the condensate drain pipe 15 is equipped with a solenoid valve 16.

[0025] Chilled water flows inside the copper tubes of the surface cooler 8. The copper tubes are sandwiched between heat sinks, which increase the contact area with the air. Although the two are not in direct contact, heat is transferred through the heat sinks. Chilled water is delivered to the copper tube inlet of the surface cooler 8 through the chilled water inlet pipe 9 and flows inside the copper tubes.

[0026] As the chilled water flows uniformly within the copper tubes, hot air from the Roots blower 5 blows across the gaps in the heat exchange fins. Since the incoming air temperature is much higher than the chilled water temperature, the heat from the air is transferred through the heat exchange fins and the copper tube walls to the chilled water inside the tubes, lowering the air temperature and achieving the cooling effect. The chilled water absorbs heat, causing its temperature to rise. The warm water, having absorbed heat, flows back to the refrigeration system through the chilled water outlet pipe 10, where it is recooled to 7-10°C. It is then sent back to the surface cooler 8 through the chilled water inlet pipe 9, completing the cycle. When the air is cooled, liquid water condenses on the heat exchange fins and copper tube walls of the surface cooler 8. If this water is not drained in time, it will accumulate inside the outer shell of the surface cooler 8, obstructing airflow and potentially causing condensate to enter the heat exchanger through the air supply duct. A seamless DN25×3 pipe is connected to the bottom of the surface cooler 8 as a condensate drain pipe 15, enabling automatic condensate drainage and preventing condensate buildup inside the surface cooler 8, thus preventing corrosion of the heat exchange tube bundle and a decrease in heat exchange efficiency. Combining the internal heat sink water channel structure of the surface cooler 8, the chilled water inlet pipe 9 and chilled water outlet pipe 10 are located on the same side of the surface cooler 8. This installation reduces the need for piping to detour around the surface cooler 8, simplifies the connection with the chilled water system, and saves installation space. Furthermore, pipe valves, filters, and other accessories can be centrally located on the same side of the surface cooler 8, eliminating the need to go to the other side of the surface cooler 8 for later maintenance and cleaning, thus reducing maintenance difficulty. The surface cooler air inlet 13 and air outlet 14 are located on the front and rear sides of the surface cooler 8, respectively, ensuring smooth airflow. Air entering from the front surface cooler air inlet 13 flows in a straight line along the heat sink inside the surface cooler 8 and exits directly from the surface cooler air outlet 14, avoiding resistance loss caused by airflow reversal and ensuring heat exchange efficiency. Moreover, the straight airflow allows for full contact between the air and the heat sink, and the low-temperature water pipes expand the heat dissipation area through the heat sink, quickly absorbing heat from the air to achieve efficient cooling and sufficient heat exchange. The condensate drain pipe 15 is installed at the bottom of the surface cooler 8, employing the principle of gravity drainage. When the air cools down, the water vapor in it condenses into liquid water. Using gravity, the condensate naturally collects at the bottom of the surface cooler 8 and is then discharged through the condensate drain pipe 15. No additional drain pump is needed, effectively reducing energy consumption and the risk of failure. This arrangement is a typical design for the surface cooler 8, its core being to ensure heat exchange efficiency while also considering the convenience of installation and maintenance and the long-term reliability of the equipment. During each 20-minute feeding cycle, a small amount of condensate will be generated inside the surface cooler 8. During feeding, the Roots blower 5 starts, and the solenoid valve 16 automatically energizes, switching to "closed" to block the flow of the medium. After feeding, the Roots blower 5 stops, the solenoid valve 16 automatically de-energizes, and the valve switches to "normally open" to allow the condensate to drain. The linkage between the Roots blower 5 and the solenoid valve 16 is existing technology.

[0027] The high-temperature air (above 40°C) discharged from the Roots blower 5 enters the air-side channel of the surface cooler inlet 13 along the outlet duct. Simultaneously, chilled water (7-10°C) circulates within the copper tubes of the surface cooler 8 through the chilled water inlet pipe 9. The high-temperature air and low-temperature chilled water undergo indirect heat exchange through the copper tubes, reducing the air temperature of the Roots blower 5 to 18-19°C. The cooled air is then transported to the star-shaped discharge device 11 through the surface cooler outlet 14 along the original outlet duct. The condensate generated during heat exchange collects in the collection tank at the bottom of the surface cooler 8. When the Roots blower 5 starts, the solenoid valve 16 automatically energizes and opens to drain the condensate. When the Roots blower 5 stops running, the solenoid valve 16 automatically de-energizes, achieving automatic and intermittent condensate drainage. The surface cooler 8 has ample space for maintenance of components such as the solenoid valve 16. Routine cleaning, such as cleaning dust from the airflow channels, can be completed within one hour without disassembling the existing piping, significantly reducing the maintenance workload and downtime of the surface cooler 8.

[0028] This invention optimizes the air intake method of the Roots blower 5, changing the original single outdoor air intake mode to a dual outdoor and indoor air intake mode with manual switching. Utilizing the characteristic that indoor ambient temperature (especially in summer) is lower than outdoor high temperature, the initial air intake temperature is reduced, decreasing the subsequent cooling load. The original outdoor air intake channel of the feeding pipeline is retained, and a manual switching valve is added to the air intake branch pipe, allowing for flexible adjustment of the air intake mode according to seasonal temperature changes. Specifically, indoor air intake is used during the high-temperature periods of summer and spring / autumn, while outdoor air intake is switched during the low-temperature periods of winter and spring / autumn, adapting to the different production environment temperature requirements of each season.

[0029] During winter and spring / autumn periods of low temperatures, the system switches to outdoor air intake, drawing air in through outdoor air inlet 1. The first switching valve 3 is opened, and the second switching valve 4 is closed, allowing the Roots blower 5 to directly draw air from the outside. To stabilize the cellulose temperature entering the xanthate machine at 18-19℃, the supply air temperature can be monitored in real time using a temperature sensor on the existing xanthate machine feed pipe. When the exhaust temperature of the Roots blower 5 is too high (around 30℃), the third switching valve 6 is closed, and the fourth switching valve 7 is opened, directing the airflow through the surface cooler 8. Simultaneously, the chilled water inlet valve on the chilled water inlet pipe 9 is increased to increase the flow rate and accelerate cooling. When the exhaust temperature of the Roots blower 5 is too low (around 20℃), the third switching valve 6 is opened, and the fourth switching valve 7 is closed, allowing the airflow to bypass the surface cooler 8 and directly supply air to the xanthate machine feed pipe 12 via the star-shaped discharge device 11. The cellulose temperature drops to 18-19℃ as it passes through the star-shaped discharge device 11 and the xanthate machine feed pipe 12.

[0030] During the high-temperature periods of summer and spring / autumn, indoor air intake is used. Air is drawn in through indoor air inlet 2. The second switching valve 4 and the fourth switching valve 7 are opened, while the first switching valve 3 and the third switching valve 6 are closed, allowing the Roots blower 5 to draw air in from indoors. The air passes through the surface cooler 8 and is cooled by chilled water. Chilled water is added through the chilled water inlet pipe 9, circulated, and then discharged through the chilled water outlet pipe 10. After the hot air temperature is reduced, it is then delivered to the xanthate machine's feed pipe 12 through the star-shaped discharge device 11. To ensure that the temperature of the cellulose entering the xanthate machine is stable at 18-19℃, the supply air temperature can be monitored in real time using a temperature sensor on the existing xanthate machine feed pipe. When the exhaust temperature of the Roots blower 5 is too high (around 40℃), the chilled water inlet valve of the chilled water inlet pipe 9 can be manually increased to increase the flow rate and accelerate cooling. When the temperature is too low (around 25℃), the chilled water inlet valve of the chilled water inlet pipe 9 can be manually decreased or closed to ensure the temperature of the cellulose entering the xanthate machine.

[0031] This invention, without altering the original feeding structure or affecting feeding efficiency, achieves precise control of the air supply temperature through coordinated cooling via outdoor and indoor dual air intake and manual switching modes. This keeps the temperature of alkali cellulose entering the xanthation machine stable within the ideal range of 18-19℃, completely solving the problem of high and fluctuating feed temperature in the original process. From the equipment level, it can effectively ensure the stability of the xanthation process and the quality of viscose products.

[0032] The surface cooler 8 is model ZHR115A-0300, the solenoid valve 16 is model 2W250-25 / AC220V-1 normally open type, and the first switching valve 3, the second switching valve 4, the third switching valve 6, and the fourth switching valve 7 are all model PZ573W-10C-DN200 bevel gear knife gate valves.

[0033] The above description is merely a preferred embodiment of this utility model. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model. Structures, devices, and operating methods not specifically described or explained in this utility model, unless otherwise specified or limited, shall be implemented using conventional methods in the field.

Claims

1. A Roots blower cooling device for quantitative feeding in adhesive production, characterized in that: The outdoor air inlet pipe (1) of the Roots blower cooling device is connected to the air inlet (13) of the surface cooler (8) via the Roots blower (5). The air outlet (14) of the surface cooler (8) is connected to the feed pipe (12) of the yellowing machine via a pipe through a star-shaped discharge device (11). A first switching valve (3) is provided at the air inlet of the outdoor air inlet pipe (1), and a fourth switching valve (7) is provided at the air inlet (13) of the surface cooler.

2. The Roots blower cooling device for quantitative feeding in adhesive production according to claim 1, characterized in that: The outdoor air inlet pipe (1) and the indoor air inlet pipe (2) are connected by a tee. The indoor air inlet pipe (2) is installed in front of the first switching valve (3). A second switching valve (4) is provided at the connection between the indoor air inlet pipe (2) and the outdoor air inlet pipe (1).

3. The Roots blower cooling device for quantitative feeding in adhesive production according to claim 1, characterized in that: The fourth switching valve (7) is connected to the air outlet (14) of the surface cooler via a pipeline through the third switching valve (6).

4. The Roots blower cooling device for quantitative feeding in adhesive production according to claim 1, characterized in that: The surface cooler (8) is equipped with a chilled water inlet pipe (9), a chilled water outlet pipe (10), and a condensate outlet pipe (15).

5. The Roots blower cooling device for quantitative feeding in adhesive production according to claim 4, characterized in that: The chilled water inlet pipe (9) and chilled water outlet pipe (10) are located on the same side of the surface cooler (8). The surface cooler air inlet (13) and surface cooler air outlet (14) are located on the front and rear sides of the surface cooler (8), respectively. The condensate outlet pipe (15) is installed at the bottom of the surface cooler (8).

6. The Roots blower cooling device for quantitative feeding in adhesive production according to claim 4, characterized in that: A solenoid valve (16) is provided on the condensate outlet pipe (15).

7. The Roots blower cooling device for quantitative feeding in adhesive production according to claim 4, characterized in that: The surface cooler (8) is model ZHR115A-0300, the solenoid valve (16) is model 2W250-25 / AC220V-1 normally open, and the first switching valve (3), the second switching valve (4), the third switching valve (6), and the fourth switching valve (7) are all bevel gear knife gate valves PZ573W-10C-DN200.

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