Air bellow unit of film transverse stretching drying oven
By designing an airflow distribution chamber and a centrifugal fan impeller structure in the transverse stretching oven for thin films, the problem of unequal air pressure between the lower and upper air boxes was solved, ensuring uniform air pressure and temperature, and improving the quality and effect of thin film stretching.
Patent Information
- Application Number
- CN202422663527.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-01
- Publication Date
- 2025-10-31
- Estimated Expiration
- 2034-11-01
AI Technical Summary
In the current transverse stretching process of film, the unequal air pressure between the lower and upper air boxes causes the film to vibrate up and down in various parts, affecting the stretching quality and effect.
A wind box unit for a transverse stretching oven for thin films is designed, employing an airflow distribution chamber and a centrifugal fan impeller structure to ensure equal air pressure output from the lower and upper wind boxes. An arc-shaped air guide plate reduces airflow turbulence, and the air outlet design avoids longitudinal airflow, thus achieving uniform air pressure and temperature.
This method achieves uniformity of wind pressure and temperature during film stretching, avoids vertical shaking of different parts of the film, and improves stretching quality and effect.
Smart Images
Figure CN223493866U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the technical field of film stretching equipment, and particularly relates to a wind box unit of a film transverse stretching oven. Background Technology
[0002] After the film is produced, it needs to be stretched laterally. During the lateral stretching process, an oven is used to heat the film. The oven contains multiple air box units, with two air box units forming a group. Each group of air box units is responsible for a corresponding stretching stroke of the film. Each air box unit includes a lower air box and an upper air box. The top of the lower air box has an upward-facing air outlet, and the bottom of the upper air box has a downward-facing air outlet. During the lateral stretching process, the film is located in the oven and moves forward, passing between the lower and upper air boxes. While moving forward, the film is stretched laterally using a stretching device. The direction of the lateral stretching is perpendicular to the direction of travel. In existing technology, the lower and upper air boxes are each equipped with a centrifugal fan, which delivers hot air through corresponding air ducts connected to the inner cavity of the air box. However, since the wind pressure of the fan will fluctuate, even if the fan power and model corresponding to the lower and upper wind boxes are the same, it is difficult to ensure that the wind pressure output by the lower and upper wind boxes is equal at every moment. If the wind pressure output by the lower and upper wind boxes is not equal, it will cause the membrane to shake up and down, affecting the stretching quality and effect. Utility Model Content
[0003] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a wind box unit for a film transverse stretching oven, which can ensure that the air pressure output by the lower wind box and the upper wind box is equal at every moment, and avoid the film from shaking up and down during the stretching process.
[0004] The objective can be achieved as follows: a wind box unit for a film transverse stretching oven, comprising an upper wind box and a lower wind box, wherein the bottom of the upper wind box has a downward-facing air outlet, and the top of the lower wind box has an upward-facing air outlet; the length of the lower and upper wind boxes is longitudinal; a centrifugal fan and an electric heating element are also provided, the centrifugal fan comprising a fan body and an impeller, characterized in that: a cuboid-shaped airflow distribution chamber is further provided, the vertical dimension of the airflow distribution chamber being greater than its longitudinal dimension, the airflow distribution chamber being located on the transverse side of the lower and upper wind boxes, and the airflow distribution chamber having a top wall, a bottom wall, an inner side wall, an outer side wall, a front side wall, and a rear side wall. The airflow distribution chamber is further divided into an air intake chamber by four partitions. The four partitions are an upper partition, a lower partition, an inner partition, and an outer partition. The longitudinal dimension of the air intake chamber is equal to the longitudinal dimension of the airflow distribution chamber, the lateral dimension of the air intake chamber is smaller than the lateral dimension of the airflow distribution chamber, and the vertical dimension of the air intake chamber is smaller than the vertical dimension of the airflow distribution chamber. Air intake windows are respectively opened at positions corresponding to the air intake chamber on the front and rear side walls. The air intake windows are equipped with mesh covers, and the electric heating element is attached to the mesh cover.
[0005] The main body of the centrifugal fan is installed on the outer side of the outer side wall of the airflow distribution chamber. The impeller of the centrifugal fan is installed inside the airflow distribution chamber and located between the outer side wall and the outer side partition. An air inlet is provided in the center of the outer side partition, and the air inlet is directly facing the center of the impeller of the centrifugal fan.
[0006] The space above the centrifugal fan impeller and the space between the top wall and the upper partition in the airflow distribution chamber form the upper air intake channel of the upper air box. The space below the centrifugal fan impeller and the space between the bottom wall and the lower partition in the airflow distribution chamber form the lower air intake channel of the lower air box. The upper part of the inner wall is provided with an upper air outlet aligned with the inner cavity of the upper air box, and the lower part of the inner wall is provided with a lower air outlet aligned with the inner cavity of the lower air box.
[0007] An arc-shaped air guide plate is also installed next to the impeller of the centrifugal fan.
[0008] The bellows unit consists of two units forming a group; in each group of bellows units, the air outlet at the uppermost position is tilted downwards, and the air outlet at the lowermost position is tilted upwards.
[0009] When describing the orientation of the components in the airflow distribution chamber, the term "inner side" refers to the side closer to the bellows in the lateral direction, and the term "outer side" refers to the side farther away from the bellows in the lateral direction. The inner wall refers to the side wall of the airflow distribution chamber closer to the bellows in the lateral direction, and the outer wall refers to the side wall of the airflow distribution chamber farther away from the bellows in the lateral direction. The inner baffle refers to the baffle of the air intake chamber closer to the bellows in the lateral direction, and the outer baffle refers to the baffle of the air intake chamber farther away from the bellows in the lateral direction.
[0010] This utility model has the following advantages and effects:
[0011] First, the airflow generated by the centrifugal fan impeller is symmetrically directed towards the upper and lower air inlet channels, thus ensuring that the air pressure output from the lower and upper air boxes is equal at all times, preventing vertical shaking of the membrane during the stretching process. Furthermore, since the air in both the lower and upper air boxes is heated by the same heating element, the temperature of the airflow output from both boxes is also ensured to be equal.
[0012] Second, an arc-shaped air guide plate is installed next to the impeller of the centrifugal fan. This can prevent the airflow thrown out by the centrifugal fan from hitting the corners of the airflow distribution chamber and generating large turbulence. This is conducive to the smooth airflow and makes the wind blown by the bellows towards the membrane closer to a calm wind.
[0013] Third, in each group of bellows units, the air outlet at the uppermost position is tilted downwards, and the air outlet at the lowermost position is tilted upwards. In this way, the air blown out at the tilted air outlets will create an air curtain effect, preventing the air blown out of the bellows unit from flowing longitudinally upstream or downstream. This ensures that most of the air blown out of each group of bellows units is discharged laterally, rather than longitudinally (in the upstream and downstream direction of the membrane operation), thus minimizing the interference with the temperature of the upstream and downstream bellows units. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the overall structure of a specific embodiment of the present utility model.
[0015] Figure 2 yes Figure 1 A front view schematic diagram of the structure shown.
[0016] Figure 3 yes Figure 2 Schematic diagram of the AA section structure.
[0017] Figure 4 yes Figure 3 Schematic diagram of the cross-sectional structure of the middle BB.
[0018] Figure 5 yes Figure 1 A three-dimensional structural diagram of the airflow distribution chamber in the structure shown.
[0019] Figure 6 yes Figure 5 The diagram shows a three-dimensional structure of the airflow distribution chamber after the cover and heating elements have been removed.
[0020] Figure 7 yes Figure 6 A front view schematic diagram of the structure shown.
[0021] Figure 8 yes Figure 7 Schematic diagram of the cross-sectional structure of the middle CC.
[0022] Figure 9 yes Figure 8 Schematic diagram of the cross-sectional structure of FF.
[0023] Figure 10 This is a schematic diagram of the airflow direction during the use of the airflow distribution chamber.
[0024] Figure 11 This is a schematic diagram illustrating how two bellows units are paired together to form a set.
[0025] Figure 12 yes Figure 11 Schematic diagram of the cross-sectional structure of the EE.
[0026] Figure 13 yes Figure 12 A magnified schematic diagram of part of G.
[0027] Figure 14 yes Figure 12 A magnified view of part H in the middle. Detailed Implementation
[0028] Figure 1 , Figure 2 , Figure 3 The air box unit of the transverse stretching oven shown includes an upper air box 51 and a lower air box 52. The bottom of the upper air box 51 is provided with an air outlet 50 facing downward, and the top of the lower air box is provided with an air outlet 50 facing upward. The lower air box 52 and the upper air box 51 are longitudinally oriented. A centrifugal fan and an electric heating element are also provided. The centrifugal fan includes a fan body 61 and an impeller 62.
[0029] Figure 1 , Figure 3 , Figure 6 , Figure 5 , Figure 7 , Figure 8As shown, a cuboid-shaped airflow distribution chamber 1 is also provided. The vertical dimension of the airflow distribution chamber 1 is larger than its longitudinal dimension. The airflow distribution chamber 1 is located on the lateral side of the lower air box 52 and the upper air box 51. The airflow distribution chamber 1 is provided with a top wall 11, a bottom wall 12, an inner side wall 13, an outer side wall 14, a front side wall 15, and a rear side wall 16. The airflow distribution chamber 1 is further divided by four partitions to form an air intake chamber 2. The four partitions are an upper partition 21, a lower partition 22, an inner partition 23, and an outer partition 24. The longitudinal dimension of the air intake chamber 2 is equal to the longitudinal dimension of the airflow distribution chamber 1, the lateral dimension of the air intake chamber 2 is smaller than the lateral dimension of the airflow distribution chamber 1, and the vertical dimension of the air intake chamber 2 is smaller than the vertical dimension of the airflow distribution chamber 1. The front sidewall 15 and the rear sidewall 16 are respectively provided with air intake windows 8 at positions corresponding to the air intake chamber 2. The air intake windows are equipped with mesh covers 80, and the electric heating element is attached to the mesh cover 80. The fan body 61 of the centrifugal fan is installed on the outer side of the outer sidewall 14 of the airflow distribution chamber, and the impeller 62 of the centrifugal fan is installed on the outer sidewall 14. The air distribution chamber 1 is located between the outer wall 14 and the outer partition 24. An air inlet 240 is centrally located on the outer partition 24, directly facing the center of the centrifugal fan impeller 62. The space above the centrifugal fan impeller 62 and between the top wall 11 and the upper partition 21 within the air distribution chamber 1 forms the upper air intake channel 31 of the upper air box. The space below the centrifugal fan impeller 62 and between the bottom wall 12 and the lower partition 22 within the air distribution chamber 1 forms the lower air intake channel 32 of the lower air box. The upper part of the inner wall 13 has an upper air outlet 41 aligned with the inner cavity of the upper air box, and the lower part of the inner wall 13 has a lower air outlet 42 aligned with the inner cavity of the lower air box. An arc-shaped guide plate 25 is also provided next to the centrifugal fan impeller 62 to prevent the airflow ejected by the centrifugal fan from hitting the corners of the air distribution chamber 1 and generating significant turbulence. The airflow direction is as follows: Figure 8 As shown by the curved arrow.
[0030] The bellows units are arranged in pairs; in each pair of bellows units, the uppermost air outlet 50 is tilted downstream, such as... Figure 14 Air outlet 50 Figure 4 Air outlet 50 Figure 12 As shown in the image on the left, the downstream air outlet 50 is tilted upstream, as... Figure 12 Air outlet 50 on the right side of the middle image Figure 13 The air outlet 50 is shown in the diagram. The upstream and downstream directions are distinguished by the direction of movement of the membrane 9; the membrane 9 moves from upstream to downstream. Figure 12 In the diagram, the direction of travel of the thin film 9 is shown by the dashed arrow V, which indicates that it is produced by... Figure 12 Move the image from left to right. Figure 12 , Figure 13 , Figure 14The solid arrows in the diagram represent the orientation of the air outlet 50, and also the direction of the airflow blown out by each air outlet 50.
[0031] The usage process and principle of the above embodiments are as follows:
[0032] During operation, the two bellows units form a group, with the two bellows units facing opposite directions. The airflow distribution chamber 1 of one bellows unit is located to the left of the corresponding upper bellows 51 and lower bellows 52, while the airflow distribution chamber 1 of the other bellows unit is located to the right of the corresponding upper bellows 51 and lower bellows 52. The direction of travel of the membrane 9 (e.g., Figure 12 (As indicated by the dashed arrow) is longitudinal and passes between the lower wind box 52 and the upper wind box 51, as shown in the image. Figure 11 , Figure 12 , Figure 13 , Figure 14 As shown; air enters the airflow distribution chamber 1 through the air inlet windows 8 on both the front and rear sides, flows to the centrifugal fan through the air inlet 240 of the outer partition 24, and then flows to the upper air inlet channel 31 and the lower air inlet channel 32 under the centrifugal force of the centrifugal fan, as shown. Figure 10 As shown, the airflow from the upper air intake channel 31 flows into the inner cavity of the upper air box 51 through the upper air outlet 41, and the airflow from the lower air intake channel 32 flows into the inner cavity of the lower air box 52 through the lower air outlet 42. Finally, the airflow is blown towards the membrane 9 through the air outlets 50 of the upper air box 51 and the lower air box 52, respectively. The direction of the airflow from the air outlets 50 is as follows: Figure 12 , Figure 13 , Figure 14 As shown by the solid line arrow.
Claims
1. A wind box unit for a transverse stretching oven for thin films, comprising an upper wind box and a lower wind box, wherein the bottom of the upper wind box has a downward-facing air outlet, and the top of the lower wind box has an upward-facing air outlet; the length of the lower wind box and the upper wind box is longitudinal; further comprising a centrifugal fan and an electric heating element, the centrifugal fan comprising a fan body and an impeller, characterized in that: A rectangular airflow distribution chamber is also provided, with its vertical dimension greater than its longitudinal dimension. The airflow distribution chamber is located on the lateral side of the lower and upper air boxes. The airflow distribution chamber has a top wall, bottom wall, inner side wall, outer side wall, front side wall, and rear side wall. Inside the airflow distribution chamber, an air intake chamber is formed by four partitions: an upper partition, a lower partition, an inner partition, and an outer partition. The longitudinal dimension of the air intake chamber is equal to the longitudinal dimension of the airflow distribution chamber, while the lateral dimension of the air intake chamber is smaller than the lateral dimension of the airflow distribution chamber, and the vertical dimension of the air intake chamber is smaller than the vertical dimension of the airflow distribution chamber. Air intake windows are respectively opened at positions corresponding to the air intake chamber on the front and rear side walls, and the air intake windows are fitted with mesh covers. The heating element is attached to the mesh cover. The main body of the centrifugal fan is installed on the outer side of the outer side wall of the airflow distribution chamber. The impeller of the fan is installed inside the airflow distribution chamber and located between the outer wall and the outer partition. An air inlet is provided in the center of the outer partition, which is directly opposite the center of the centrifugal fan impeller. The space above the centrifugal fan impeller and the space between the top wall and the upper partition in the airflow distribution chamber form the upper air intake channel of the upper air box. The space below the centrifugal fan impeller and the space between the bottom wall and the lower partition in the airflow distribution chamber form the lower air intake channel of the lower air box. The upper part of the inner wall is provided with an upper air outlet aligned with the inner cavity of the upper air box, and the lower part of the inner wall is provided with a lower air outlet aligned with the inner cavity of the lower air box.
2. The air box unit of the film transverse stretching oven according to claim 1, characterized in that: An arc-shaped air guide plate is also installed next to the impeller of the centrifugal fan.
3. The air box unit of the film transverse stretching oven according to claim 1 or 2, characterized in that: The bellows unit consists of two units forming a group; in each group of bellows units, the air outlet at the uppermost position is tilted downwards, and the air outlet at the lowermost position is tilted upwards.