A raw material drying device for producing a photovoltaic thin film
By combining external jacket hot air heating with internal stirring shaft and hollow paddle heat transfer oil heating, the problem of uneven hot air distribution and agglomeration of EVA particles in existing equipment is solved, achieving efficient and uniform drying effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHE JIANG GUANG HUI DA XIN CAI LIAO KE JI YOU XIAN GONG SI
- Filing Date
- 2025-08-28
- Publication Date
- 2026-08-04
AI Technical Summary
Existing drying equipment suffers from uneven hot air distribution, low drying efficiency, high energy consumption, and inconsistent drying levels between the surface and core of EVA particles. Furthermore, some equipment has a complex structure and lacks dedicated stirring and heat conduction structures, which makes EVA particles prone to clumping.
It adopts a three-dimensional heating mode that combines external jacket hot air heating with internal stirring shaft and hollow heat-conducting oil heating in the blades. The frame-type stirring blades agitate the EVA particles to ensure uniform heating and drying in a vacuum environment.
This process ensures uniform heating of EVA particles, prevents clumping, improves drying efficiency, and guarantees a large heat conduction area, resulting in a highly efficient drying effect without any dead spots.
Smart Images
Figure CN224593660U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of drying technology, specifically to a raw material drying device for producing photovoltaic thin films. Background Technology
[0002] EVA is a key raw material for producing encapsulating films for photovoltaic modules, but it has a strong water absorption capacity. If the water content in the raw material is too high, the water will vaporize and form bubbles during the subsequent high-temperature melt extrusion film formation process, leading to defects such as pinholes and white spots in the film, which seriously affects the light transmittance, insulation, and encapsulation life of the film. Therefore, EVA particles must be thoroughly dried before feeding and extrusion.
[0003] Currently, most common drying methods are ordinary hot air circulation drying, which suffers from problems such as uneven hot air distribution, low drying efficiency, high energy consumption, and inconsistent drying levels between the particle surface and core. Although some equipment uses vacuum drying, its complex structure and lack of dedicated stirring and heat transfer structures for EVA granules make the material prone to clumping, resulting in unsatisfactory drying effects. Utility Model Content
[0004] To address the shortcomings of the existing technology, this utility model proposes a raw material drying device for producing photovoltaic thin films.
[0005] To achieve the above-mentioned technical effects, the present invention adopts the following solution: A raw material drying device for producing photovoltaic thin films includes a drying host, a heating system, a vacuum system, and a control system. The drying host includes a sealed drying chamber with a feed inlet and a vacuum outlet at the top and a discharge outlet at the bottom. An insulation jacket is provided around the outer periphery of the chamber. A drive shaft driven by a drive motor is vertically positioned at the center of the drying chamber, and several layers of frame-type stirring blades are fixedly mounted on the drive shaft. The drive shaft has a hollow internal channel for heat-conducting oil, with its top and bottom ends connected to an external heat-conducting oil circulation loop via rotary joints. The frame-type stirring blades are hollow, and their internal cavities are connected to the heat-conducting oil channel of the drive shaft.
[0006] In a preferred embodiment, the frame-type stirring blade includes a central collar fixed to the drive shaft and multiple hollow support arms radiating outward from the central collar. Scrapers are connected between adjacent hollow support arms, and the outer edge of the scraper is adapted to the shape of the inner wall of the drying chamber and maintains contact or a small gap.
[0007] In a preferred embodiment, the drying chamber has a circular cross-section, and the frame-type stirring blades have a cross-shaped or star-shaped structure.
[0008] In a preferred embodiment, a pneumatic butterfly valve is provided at the discharge port.
[0009] In a preferred embodiment, the heating system includes a heating element and a hot air circulation fan disposed within the insulation jacket.
[0010] In a preferred embodiment, the inner wall of the drying chamber, the outer surface of the drive shaft, and the surface of the frame-type stirring blades are all coated with an anti-stick coating.
[0011] Compared with existing technologies, the beneficial effects are: This utility model has a simple structure and is easy to use. It adopts a combination of external jacket hot air heating and internal stirring shaft and blade hollow heat-conducting oil heating to form a three-dimensional heating mode from the outside to the inside and from the inside to the outside. It has a large heat conduction area and high efficiency, ensuring that the EVA particles are heated evenly and without any drying dead corners. Attached Figure Description
[0012] Figure 1 This is a schematic diagram of the structure of this utility model.
[0013] Reference numerals: 1. Drying chamber; 2. Feed inlet; 3. Vacuum port; 4. Discharge port; 5. Insulation jacket; 6. Drive shaft; 7. Drive motor; 8. Frame-type stirring blade; 9. Heat transfer oil circulation loop; 10. Pneumatic butterfly valve; 11. Heating element; 12. Hot air circulation fan. Detailed Implementation
[0014] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.
[0015] A raw material drying device for producing photovoltaic thin films includes a drying host, a heating system, a vacuum system, and a control system. The drying host includes a sealed drying chamber 1, with a feed inlet 2 and a vacuum port 3 at the top and a discharge port 4 at the bottom. A heat-insulating jacket 5 is provided on the outer periphery of the chamber. A drive shaft 6 driven by a drive motor 7 is vertically arranged at the center of the drying chamber 1. Several layers of frame-type stirring blades 8 are fixedly arranged on the drive shaft 6. The drive shaft 6 has a hollow heat transfer oil channel inside, and its top and bottom ends are connected to an external heat transfer oil circulation loop 9 through rotary joints. The frame-type stirring blades 8 have a hollow structure, and their internal cavities are connected to the heat transfer oil channel of the drive shaft 6.
[0016] In a preferred embodiment, the frame-type stirring blade 8 includes a central collar fixed to the drive shaft 6 and a plurality of hollow support arms radiating outward from the central collar. Scrapers are connected between adjacent hollow support arms, and the outer edge of the scraper is adapted to the shape of the inner wall of the drying chamber 1 and maintains contact or a small gap.
[0017] The unique frame-type stirring blades 8 can fully agitate EVA particles during rotation, preventing them from clumping and exposing all particle surfaces to the vacuum environment, facilitating moisture escape. The scrapers on the outer edge of the blades can remove material that may adhere to the inner wall of the chamber, keeping the wall clean and ensuring heat transfer efficiency.
[0018] In a preferred embodiment, the drying chamber 1 has a circular cross-section, and the frame-type stirring blade 8 has a cross-shaped or star-shaped structure.
[0019] In a preferred embodiment, a pneumatic butterfly valve 10 is provided at the discharge port 4.
[0020] In a preferred embodiment, the heating system further includes a heating element 11 and a hot air circulation fan disposed within the insulation jacket 5.
[0021] The system combines external jacketed hot air heating with hollow heat-conducting oil heating of the internal stirring shaft and blades to form a three-dimensional heating mode from the outside to the inside and from the inside to the outside. This results in a large heat transfer area and high efficiency, ensuring that the EVA particles are heated evenly and without any dead spots in the drying process.
[0022] In a preferred embodiment, the inner wall of the drying chamber 1, the outer surface of the drive shaft 6, and the surface of the frame-type stirring blade 8 are all coated with an anti-stick coating.
[0023] In the description of this utility model, it should be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this utility model and simplify the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.
[0025] Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.
Claims
1. A raw material drying apparatus for producing photovoltaic thin films, characterized in that, The system includes a drying host, a heating system, a vacuum system, and a control system. The drying host includes a sealed drying chamber (1), with a feed inlet (2) and a vacuum port (3) at the top and a discharge port (4) at the bottom. A heat insulation jacket (5) is provided on the outer periphery of the chamber. A drive shaft (6) driven by a drive motor (7) is vertically arranged in the center of the drying chamber (1). Several layers of frame-type stirring blades (8) are fixedly arranged on the drive shaft (6). The drive shaft (6) has a hollow heat transfer oil channel inside, and its top and bottom ends are connected to the external heat transfer oil circulation loop (9) through rotary joints. The frame-type stirring blades (8) have a hollow structure, and their internal cavities are connected to the heat transfer oil channel of the drive shaft (6).
2. The raw material drying device for producing a photovoltaic film according to claim 1, characterized by, The frame-type stirring blade (8) includes a central collar fixed to the drive shaft (6) and multiple hollow support arms radiating outward from the central collar. Scrapers are connected between adjacent hollow support arms. The outer edge of the scraper is adapted to the shape of the inner wall of the drying chamber (1) and maintains contact or a small gap.
3. The raw material drying device for producing a photovoltaic film according to claim 2, wherein The drying chamber (1) has a circular cross-section, and the frame-type stirring blade (8) has a cross-shaped or star-shaped structure.
4. The raw material drying device for producing a photovoltaic film according to claim 1, characterized in that, A pneumatic butterfly valve (10) is provided at the discharge port (4).
5. The raw material drying device for producing a photovoltaic film according to claim 1, wherein The heating system also includes a heating element (11) and a hot air circulation fan disposed within the insulation jacket (5).
6. The raw material drying device for producing a photovoltaic film according to claim 1, wherein The inner wall of the drying chamber (1), the outer surface of the drive shaft (6), and the surface of the frame-type stirring blade (8) are all coated with an anti-stick coating.