Dynamic differential pressure regulation drainage device for dryer of paper machine

Abstract

The utility model discloses a paper machine drying cylinder pressure difference dynamic regulation drainage device, including cylinder body and hollow shaft, be provided with steam pipe in the hollow shaft, be provided with drain pipe in the steam pipe, be provided with pressure difference sensor and siphon in the cylinder body, and this siphon is connected with the drain pipe, the import end of steam pipe is provided with steam connector pipe, and the compressed air pipe is connected on this steam connector pipe, and the regulating valve is set up on this compressed air pipe. The technical scheme provided by the utility model solves the problem of low pressure difference condensate discharge difficulty caused by the steam consumption little and the like, is applicable to the high -speed paper machine and the steam energy -conserving reconstruction machine platform, and the maintenance cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of papermaking technology, and in particular to a dynamic adjustment and drainage device for differential pressure of the drying cylinder of a papermaking machine. Background Technology

[0002] In the papermaking process, the drying cylinder is a key drying device, and its drainage efficiency directly affects the paper drying quality and production energy consumption. Traditional drying cylinders mostly use siphon drainage, relying on the steam pressure difference inside and outside the cylinder to discharge condensate. However, in actual operation, due to factors such as steam pressure fluctuations and cylinder speed changes, the pressure difference is prone to instability: when the pressure difference is too small, condensate cannot be discharged in time, resulting in a decrease in the heat transfer efficiency of the drying cylinder and uneven paper drying.

[0003] Therefore, there is an urgent need for a drying cylinder drainage device that can dynamically adjust the pressure difference and optimize drainage performance. Utility Model Content

[0004] In view of the shortcomings of the prior art, the purpose of this utility model is to provide a paper machine drying cylinder pressure differential dynamic adjustment drainage device, which aims to solve the technical problem that the drying cylinder drainage in the prior art relies on a fixed pressure differential and is difficult to dynamically adapt to changes in working conditions, resulting in untimely discharge of condensate.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A paper machine drying cylinder pressure differential dynamic adjustment drainage device includes a cylinder body and a hollow shaft. A steam pipe is installed inside the hollow shaft, and a drain pipe is installed inside the steam pipe. A differential pressure sensor and a siphon pipe are installed inside the cylinder body, and the siphon pipe is connected to the drain pipe. A steam connector is installed at the inlet end of the steam pipe, and a compressed air pipe is connected to the steam connector. A regulating valve is installed on the compressed air pipe.

[0007] Furthermore, the paper machine drying cylinder pressure differential dynamic adjustment drainage device also includes a controller, which is electrically connected to the pressure differential sensor and the regulating valve respectively. The controller has a preset pressure differential threshold range and can adjust the opening of the regulating valve according to the detection value of the pressure differential sensor.

[0008] Furthermore, in the aforementioned paper machine drying cylinder pressure differential dynamic adjustment drainage device, the regulating valve is a ball valve.

[0009] Furthermore, in the aforementioned paper machine drying cylinder pressure differential dynamic adjustment drainage device, a one-way valve is also provided on the compressed air pipe, which is located downstream of the regulating valve.

[0010] Furthermore, in the aforementioned paper machine drying cylinder pressure differential dynamic adjustment drainage device, the steam pipe is externally fitted with an insulating sleeve.

[0011] Furthermore, in the aforementioned paper machine drying cylinder pressure differential dynamic adjustment drainage device, a carbon ring sealing assembly is provided at the connection between the journal of the hollow shaft and the cylinder body.

[0012] Furthermore, in the aforementioned paper machine drying cylinder pressure differential dynamic adjustment and drainage device, the air inlet end of the compressed air pipe is connected to an air source processing unit, which includes a filter, a pressure reducing valve, and an oil mist lubricator connected in sequence.

[0013] Beneficial Effects: This utility model provides a dynamic adjustment and drainage device for differential pressure in the drying cylinder of a paper machine. Compared with existing technologies, it incorporates a compressed air pipe, a regulating valve, and a differential pressure controller. This allows for adjustment of the compressed air flow rate according to actual production conditions to maintain sufficient pressure within the drying cylinder and keep the drainage differential pressure within the normal range, thus solving the problem of poor condensate drainage under low differential pressure. Furthermore, the combination of a ball valve and a check valve ensures the accuracy and unidirectional flow of compressed air regulation; the aluminum silicate insulation sleeve reduces steam heat loss; and the carbon ring sealing assembly enhances sealing performance. Attached Figure Description

[0014] Figure 1 A schematic diagram of the structure of the paper machine drying cylinder pressure differential dynamic adjustment drainage device provided by this utility model.

[0015] Explanation of reference numerals in the attached figures:

[0016] 1. Cylinder block;

[0017] 2. Hollow shaft; 21. Carbon ring seal assembly;

[0018] 3. Insulating sleeve;

[0019] 4. Steam pipe; 41. Steam connection pipe;

[0020] 5. Siphon tube;

[0021] 6. Drain pipe; 62. Drain connection pipe;

[0022] 7. Compressed air pipe;

[0023] 81. Control valve; 82. Check valve; 83. Differential pressure sensor. Detailed Implementation

[0024] To make the objectives, technical solutions, and effects of this utility model clearer and more explicit, the present utility model is further described in detail below. It should be understood that the specific embodiments described herein are merely for explaining this utility model and are not intended to limit this utility model.

[0025] Please see Figure 1This utility model provides a dynamic pressure differential adjustment and drainage device for a paper machine drying cylinder. The accompanying drawings are for illustrative purposes only and are not proportional to the actual product. The drawings only show structures relevant to the innovation of this application; some conventional structures are not specifically depicted. Dashed arrows in the drawings indicate the direction of steam flow, while straight arrows indicate the direction of drainage. For ease of observation, cross-sectional lines of the insulation sleeve, steam pipe, and drainage pipe are shown in the drawings; cross-sectional lines of other structures are not shown.

[0026] The paper machine drying cylinder differential pressure dynamic adjustment drainage device includes a cylinder body 1 and a hollow shaft 2. A steam pipe 4 is installed inside the hollow shaft, and a drain pipe 6 is installed inside the steam pipe. The steam pipe and drain pipe are coaxially arranged. A differential pressure sensor 83 and a siphon pipe 5 are installed inside the cylinder body, and the siphon pipe 5 is connected to the drain pipe 6. A steam connector 41 is installed at the inlet end of the steam pipe 4, and a compressed air pipe 7 is connected to the steam connector. A regulating valve 81 is installed on the compressed air pipe. The differential pressure sensor is used to detect the pressure difference between the inside of the cylinder body and the outlet end of the drain pipe. The outlet end of the drain pipe refers to the port connected to an external drainage pipe (such as the drain connector 62).

[0027] One end of the siphon tube is immersed in the condensate at the bottom of the cylinder, and the other end is connected to the drain pipe. The condensate is drawn into the drain pipe by the pressure difference. The installation angle and depth of the siphon tube need to be adapted to the cylinder speed (especially high-speed paper machines) to avoid drainage interruption. This setting is not the innovation of this application, so it is not specifically limited here.

[0028] During cylinder drying operation, steam is introduced into the cylinder for heating. The steam condenses into water upon contact with the condensate, creating a mixed environment of condensate and steam. The drain pipe serves as a drainage channel, connecting to external pipes (as shown in the diagram). A differential pressure sensor detects the pressure difference between the area inside the cylinder (containing steam and condensate) and the pressure at the drain pipe outlet to reflect the dynamic condition of condensate discharge. When the pressure difference is sufficient, condensate can smoothly pass through the siphon pipe and be discharged through the drain pipe. When the pressure difference is insufficient, it triggers the regulating valve on the compressed air pipe to increase the pressure difference by supplementing compressed air, ensuring efficient condensate discharge.

[0029] Furthermore, the paper machine drying cylinder pressure differential dynamic adjustment drainage device also includes a controller (not shown in the figure). This controller is electrically connected to both the pressure differential sensor and the regulating valve. The controller has a preset pressure differential threshold range and can adjust the opening of the regulating valve according to the detection value of the pressure differential sensor. Preferably, the controller is a PLC (Programmable Logic Controller), which can stably receive electrical signals (such as analog signals) from the pressure differential sensor and perform logical judgments based on the preset pressure differential threshold range (such as a specific numerical range that can be set in the program). The controller can output control signals (such as switching signals or analog signals) to adjust the opening of the regulating valve, thereby achieving precise control of the compressed air intake and dynamically balancing the pressure differential within the drying cylinder.

[0030] Preferably, the differential pressure threshold range is limited to 0.3~0.4MPa. When the differential pressure sensor detects that the real-time differential pressure value in the cylinder is lower than 0.3MPa, it indicates that the pressure in the cylinder is insufficient, which may lead to poor drainage of condensate. At this time, the controller triggers the regulating valve to open, and introduces compressed air to supplement the pressure, thereby increasing the differential pressure and enhancing the drainage power. When the differential pressure value is higher than 0.4MPa, it indicates that the pressure in the cylinder has met the drainage requirements. The controller instructs the regulating valve to close to avoid excessive compressed air intake, which may lead to steam waste or abnormal pressure rise.

[0031] Preferably, the regulating valve 81 is a ball valve. Ball valves have the characteristics of low flow resistance and rapid opening and closing, which can quickly respond to controller commands and accurately adjust the compressed air supply; they also have a simple structure and good sealing performance, which can effectively prevent compressed air leakage, and are suitable for the high-frequency control requirements of dynamic adjustment of the drying cylinder pressure difference, ensuring the stable operation of the device.

[0032] Furthermore, a one-way valve 82 is also installed on the compressed air pipe, which is located downstream of the regulating valve. Since the one-way valve is located downstream of the regulating valve, it can prevent steam or condensate in the drying cylinder from flowing back into the compressed air pipe, avoiding contamination of the air source or affecting the normal operation of the regulating valve, ensuring the stability of the one-way flow of the compressed air system, and meeting the safety requirements of dynamic differential pressure adjustment of the device.

[0033] Furthermore, an insulating sleeve 3 is provided on the outside of the steam pipe, and the insulating sleeve is made of aluminum silicate. The aluminum silicate insulating sleeve outside the steam pipe can reduce the loss of steam heat, maintain the stable steam pressure in the cylinder to ensure pressure difference; at the same time, it can prevent the high-temperature steam pipe from causing thermal damage to surrounding components, thus meeting the requirements of high efficiency, energy saving and safe operation of the device.

[0034] Furthermore, a carbon ring sealing assembly 21 is provided at the connection between the journal of the hollow shaft and the cylinder body. The carbon ring sealing assembly (usually 2 to 4 carbon rings) can enhance the sealing performance at the connection between the journal of the hollow shaft and the cylinder body, prevent steam or condensate leakage, ensure stable internal pressure to maintain an effective pressure difference, and meet the sealing requirements of efficient drainage under low pressure difference of the device.

[0035] Furthermore, the air inlet of the compressed air pipe is connected to an air source processing unit (not shown in the figure, located upstream of the regulating valve). The air source processing unit includes a filter, a pressure reducing valve, and an oil mist lubricator connected in sequence. The filter in the air source processing unit removes impurities from the compressed air, the pressure reducing valve stabilizes the air pressure, and the oil mist lubricates the pipeline components. The three work together to ensure that the incoming compressed air is clean and the pressure is stable, reducing wear on components such as the regulating valve, ensuring accurate and reliable differential pressure regulation, and meeting the high-efficiency operation requirements of the device.

[0036] To facilitate understanding, the working principle is briefly described below: During the operation of the drying cylinder, the condensate generated by the condensation of steam inside the cylinder is discharged through the siphon and drain pipe. The differential pressure sensor detects the pressure difference between the inside of the cylinder and the outlet of the drain pipe in real time. When the pressure difference is lower than the preset threshold (0.3MPa) due to reasons such as insufficient steam consumption, the controller drives the regulating valve on the compressed air pipe to open, and compressed air is introduced to supplement the pressure and increase the pressure difference. When the pressure difference is higher than the threshold (0.4MPa), the regulating valve closes and the supply of compressed air stops. By dynamically adjusting the pressure difference, the efficient discharge of condensate is ensured, while adapting to the steam and compressed air switching requirements during the production of different paper types.

[0037] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. It is understood that those skilled in the art can make equivalent substitutions or modifications based on the technical solution and inventive concept of the present utility model, and all such modifications or substitutions should fall within the protection scope of the present utility model.

Claims

1. A dynamic adjustment and drainage device for differential pressure of a paper machine drying cylinder, comprising a cylinder body and a hollow shaft, characterized in that: A steam pipe is installed inside the hollow shaft, and a drain pipe is installed inside the steam pipe; a differential pressure sensor and a siphon pipe are installed inside the cylinder, and the siphon pipe is connected to the drain pipe; a steam connector is installed at the inlet end of the steam pipe, and a compressed air pipe is connected to the steam connector, and a regulating valve is installed on the compressed air pipe.

2. The paper machine drying cylinder pressure differential dynamic adjustment drainage device according to claim 1, characterized in that: It also includes a controller, which is electrically connected to the differential pressure sensor and the regulating valve respectively. The controller has a preset differential pressure threshold range and can adjust the opening of the regulating valve according to the detection value of the differential pressure sensor.

3. The paper machine drying cylinder pressure differential dynamic adjustment drainage device according to claim 1, characterized in that: The regulating valve is a ball valve.

4. The paper machine drying cylinder pressure differential dynamic adjustment drainage device according to claim 1, characterized in that: The compressed air pipe is also equipped with a one-way valve, which is located downstream of the regulating valve.

5. The paper machine drying cylinder pressure differential dynamic adjustment drainage device according to claim 1, characterized in that: The steam pipe is fitted with an insulating sleeve.

6. The paper machine drying cylinder pressure differential dynamic adjustment drainage device according to claim 1, characterized in that: A carbon ring sealing assembly is provided at the connection between the journal of the hollow shaft and the cylinder block.

7. The paper machine drying cylinder pressure differential dynamic adjustment drainage device according to claim 1, characterized in that: The air inlet of the compressed air pipe is connected to an air source processing unit, which includes a filter, a pressure reducing valve, and an oil mist lubricator connected in sequence.

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