Rapid cooling equipment for blister tray processing

Abstract

The utility model relates to the technical field of plastic vacuum forming machines, in particular to rapid cooling equipment for processing a plastic vacuum forming disc, which comprises a double-flow-channel water mist cooling spray head arranged right above a mold of a plastic vacuum forming machine, the double-flow-channel water mist cooling spray head comprises a central flow channel for conveying high-pressure gas, an annular flow channel for conveying cooling water, a communicating hole for communicating the central flow channel with the annular flow channel, and an impeller assembly for controlling the communicating state of the communicating hole. When an impeller is driven by airflow to rotate, a convex block periodically extrudes a ball to enable the ball to axially move and form sealing with a conical sealing face; and the communication between the annular flow channel and the central flow channel is cut off, the balls can be reset to the initial position under the action of the pressure of the cooling water, so that the communicating holes recover to an intersection passage of the cooling water and the gas, and therefore, water mist-gas flow alternately cools the plastic uptake plate, a stable and continuous water film layer is prevented from being formed on the surface of the plastic uptake plate, and the heat exchange efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of blister packaging technology, specifically a rapid cooling device for processing blister trays. Background Technology

[0002] Vacuum forming trays are widely used in electronic components, medical devices, food packaging, and other fields. Their production process includes heating, forming, cooling, and demolding. The cooling stage is a crucial step determining production efficiency and product quality. Traditional natural cooling methods are inefficient and prone to problems such as product deformation and uneven shrinkage. Existing vacuum forming machines are equipped with rapid cooling devices that use atomized water, gas, or a combination of both to quickly cool the vacuum forming sheet. This significantly shortens the production cycle while improving product flatness and dimensional accuracy.

[0003] However, existing water-cooled or atomized water plus gas cooling equipment has the following problems when cooling thermoformed panels: When the atomized water flow rate density (water volume per unit area) exceeds the critical evaporation threshold, even if the panel temperature reaches 200-250℃, the latent heat of phase change of water (2260kJ / kg) cannot be absorbed quickly, resulting in some liquid water not evaporating completely; on the other hand, mold release agents or plastic oligomers often remain on the surface of the thermoformed panel, resulting in contact angle hysteresis (alternating between hydrophobic region θ>90° and hydrophilic region θ<30°). At the same time, liquid water diffuses and wets along the micropores or scratches on the thermoformed panel, eventually forming a water film layer (surface wetting film retention) on the surface of the thermoformed panel. The water film layer blocks the direct contact between the atomized water and the surface of the thermoformed panel, preventing heat from being transferred quickly through evaporation, thereby reducing the overall cooling rate. Utility Model Content

[0004] The purpose of this invention is to provide a rapid cooling device for the processing of blister packs using alternating water mist and airflow cooling, in order to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A rapid cooling device for blister packaging includes a dual-channel water mist cooling nozzle positioned directly above the mold of the blister packaging machine. The dual-channel water mist cooling nozzle comprises:

[0007] The central flow channel is used to transport high-pressure gas;

[0008] An annular flow channel, coaxially arranged around the outside of the central flow channel, is used to transport cooling water;

[0009] A connecting hole is evenly opened circumferentially along the side wall of the central flow channel. A conical sealing surface is provided near the inner wall of the central flow channel, and a ball bearing is movably arranged near the conical sealing surface.

[0010] An impeller assembly is disposed inside the central flow channel, including an impeller coaxially disposed with the central flow channel and an annular rotating block driven therefrom, wherein the annular rotating block has evenly distributed protrusions on its outer circumference.

[0011] When the impeller is driven to rotate by the airflow, the protrusion periodically squeezes the ball to move axially and forms a seal with the conical sealing surface, cutting off the connection between the annular flow channel and the central flow channel.

[0012] Preferably, the outlet end of the central flow channel is fixedly connected to a first Venturi tube.

[0013] Preferably, the nozzle assembly is detachably connected to the outlet end of the first venturi tube.

[0014] Preferably, the nozzle assembly includes a distribution cavity, the end face of which is provided with a plurality of tapered holes, the tapered holes being fixedly connected to the nozzle, and the nozzle and the tapered holes forming a second Venturi tube.

[0015] Preferably, a water distribution hole is formed around the connecting hole, and the water distribution hole is inclined and connected to the connecting hole.

[0016] Preferably, the number of circumferentially distributed bumps is an integer multiple of the number of connecting holes, and the working surface of the bumps is provided with a polytetrafluoroethylene wear-resistant layer.

[0017] Preferably, the dual-channel water mist cooling nozzle is connected to the vacuum forming machine via a linear actuator.

[0018] Compared with the prior art, the beneficial effects of this utility model are:

[0019] 1. By setting a central flow channel and an annular flow channel around the central flow channel, and setting an impeller assembly inside the central flow channel, when the airflow in the central flow channel drives the impeller to rotate, the protrusion periodically squeezes the ball bearings to form a seal with the conical sealing surface, cutting off the connection between the annular flow channel and the central flow channel; the ball bearings can be reset to the initial position under the action of cooling water pressure, so that the connecting hole restores the passage for the convergence of cooling water and gas, thereby realizing the alternating cooling of the vacuum forming plate by water mist and airflow, avoiding the formation of a stable and continuous water film layer on the surface of the vacuum forming plate, and improving the heat exchange efficiency.

[0020] 2. Water distribution holes are set around the connecting holes to disperse the water flow into the central channel as much as possible. Under the action of airflow, the water is initially atomized. A first Venturi tube and a second Venturi tube formed by the conical hole and the nozzle are set in series with the central channel to further atomize the water, so that the atomized water particles distributed by the nozzle are small and uniform, thereby improving the evaporation efficiency after contact with the thermoforming panel. Attached Figure Description

[0021] Figure 1 A schematic diagram of the overall structure of this utility model;

[0022] Figure 2 This is a schematic diagram of the structure of the dual-channel water mist cooling nozzle housing after planing.

[0023] Figure 3 This utility model Figure 2 Enlarged view of point A in the middle;

[0024] Figure 4 Cross-sectional view of the connecting hole of this utility model;

[0025] Figure 5 This utility model presents a schematic diagram of the impeller assembly structure.

[0026] In the diagram: 1. Central flow channel; 2. Air inlet; 3. Annular flow channel; 4. Water inlet; 5. Connecting hole; 51. Conical sealing surface; 52. Water distribution hole; 6. Ball bearing; 7. Impeller assembly; 71. Central shaft; 72. Impeller; 73. Annular rotating block; 74. Protrusion; 75. First fixing rod; 76. Second fixing rod; 8. First venturi tube; 9. Nozzle assembly; 91. Distribution chamber; 92. Conical hole; 93. Nozzle; 10. Mold. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0028] This utility model provides a technical solution:

[0029] See Figure 1 and Figure 2 A rapid cooling device for blister packaging includes a dual-channel water mist cooling nozzle positioned directly above the mold 10 of the blister packaging machine. The dual-channel water mist cooling nozzle includes:

[0030] The central flow channel 1 has an air inlet 2 at one end and is connected to an external air source through an air pipe. A regulating valve is installed at the air inlet 2 to regulate the gas flow rate.

[0031] The annular flow channel 3 is coaxially arranged around the outside of the central flow channel 1. The inlet 4 is provided on its circumference and is connected to the water tank through a water pipe. Similarly, a regulating valve is also provided at the inlet 4 to realize the regulation of cooling water flow.

[0032] See Figure 3 and Figure 4The connecting hole 5 is evenly opened along the circumference of the side wall of the central flow channel 1. A conical sealing surface 51 is provided near the inner wall of the central flow channel 1. A ball 6 is movably arranged near the conical sealing surface 51. The ball 6 can roll freely and move axially to approach or away from the conical surface. In this application, the ball 6 is a hollow structure.

[0033] See Figure 5 The impeller assembly 7 is disposed inside the central flow channel 1, including a central shaft 71, an impeller 72 coaxially disposed with the central flow channel 1, and an annular rotating block 73 driven by the impeller 72. The impeller 72 is fixedly connected to the central shaft 71, and the annular rotating block 73 is fixedly connected to the central shaft 71 through a first fixing rod 75. The central shaft 71 is fixedly connected to the inner ring of the bearing, and the outer ring of the bearing is fixedly connected to the inner wall of the central flow channel 1 through a second fixing rod 76. In order to reduce the interaction between the first fixing rod 75 and the second fixing rod 76 and the gas in the central flow channel 1, the cross-sections of the first fixing rod 75 and the second fixing rod 76 are teardrop-shaped. In order to avoid the disturbance generated by the airflow after passing through the second fixing rod 76 from affecting the operation of the impeller 72, the impeller 72 is disposed upstream of the second fixing rod 76 in this application. In addition, the impeller 72 in this application adopts a 6-blade design of NACA 6 series with an installation angle of 12 to 15 degrees. The blades are made of titanium alloy and have a hollow design. While ensuring mechanical strength, the moment of inertia is minimized as much as possible. Of course, other forms of blades in the prior art can also be selected according to the actual situation.

[0034] See Figure 2 , Figure 3 and Figure 5 The outer circumference of the annular rotating block 73 is provided with evenly distributed protrusions 74. The protrusions 74 are part of the annular block arranged concentrically with the annular rotating block 73. The protrusions 74 have a gap with the inner wall of the central flow channel 1 in the radial direction. The beginning and end of the protrusions 74 are smoothly transitioned to the annular rotating block 73 through arc surfaces or inclined surfaces. When the impeller 72 is driven to rotate by the airflow, the protrusions 74 periodically squeeze the balls 6 to make them move axially and form a seal with the conical sealing surface 51, cutting off the connection between the central flow channel 1 and the annular flow channel 3.

[0035] The force exerted by the cooling water in the annular flow channel 3 on the ball 6 must be greater than the force exerted by the gas in the central flow channel 1 on the ball 6, in order to prevent the ball 6 from failing to reset under the pressure of the cooling water. At the same time, the pressure of the cooling water should not be too high, so as to reduce the resistance when the protrusion 74 pushes the ball 6 close to the conical sealing surface 51 to complete the connection of the connecting hole 5.

[0036] See Figure 2 The outlet end of the central flow channel 1 is fixedly connected to the first venturi tube 8, and the nozzle of the first venturi tube 8 further atomizes the water mist.

[0037] The outlet end of the first venturi tube 8 is connected to the nozzle assembly 9 via a thread, which makes it convenient to select the appropriate size nozzle assembly 9 according to the size of the thermoforming plate to be cooled.

[0038] The nozzle assembly 9 includes a distribution chamber 91, with a plurality of tapered holes 92 formed on the end face of the distribution chamber 91. The tapered holes 92 are fixedly connected to the nozzle 93, and the nozzle 93 and the tapered holes 92 form a second venturi tube, which re-atomizes the water mist.

[0039] See Figure 3 and Figure 4 A water distribution hole 52 is provided around the connecting hole 5. The water distribution hole 52 is inclined and connected to the connecting hole 5. The arrangement of the water distribution hole 52 is, on the one hand, to disperse the cooling water entering the central flow channel 1 as much as possible, so as to facilitate the initial atomization by high-speed airflow in the central flow channel 1. On the other hand, when the ball 6 is not in contact with the protrusion 74, the ball 6 is close to the water outlet of the connecting hole 5 under the action of water flow. The inclined water distribution hole 52 is located at one end in the connecting hole 5 near the conical surface, thereby avoiding the ball 6 at this time and reducing the impact of the ball 6 on the water output of the connecting hole 5.

[0040] The number of protrusions 74 distributed circumferentially is an integer multiple of the number of connecting holes 5. When the airflow velocity and pressure in the central hole are stable, that is, when the speed of impeller 72 is constant, the number of protrusions 74 determines the frequency of gas-liquid alternation. The working surface of protrusions 74 is provided with a polytetrafluoroethylene wear-resistant layer.

[0041] The dual-channel water mist cooling nozzle is connected to the vacuum forming machine through a linear actuator, thereby enabling the dual-channel water mist cooling nozzle to move up and down, adjusting the distance between it and the vacuum forming plate during operation. At the same time, it can control the dual-channel water mist cooling nozzle to rise when not in operation to avoid interference with the feeding mechanism or other lateral moving parts. The linear actuator can be a hydraulic or pneumatic telescopic rod, a lead screw or lead screw slider assembly, a gear rack, or other commonly used components in machinery that can control the movement distance.

[0042] It should be noted that this invention has the best cooling effect on male molds used in vacuum forming machines.

[0043] The working process of this utility model is as follows: The vacuum forming machine uses a vacuum system to tightly adhere the sheet material to the mold 10. After vacuum forming is completed, the dual-channel water mist cooling nozzle, driven by a linear actuator, approaches the vacuum forming plate to a set distance. A regulating valve connects and adjusts the flow rates of gas and cooling water to the set values. The gas drives the impeller 72 to rotate through the central channel 1, and drives the annular rotating block 73 to rotate through the central shaft 71. When the protrusion 74 on the annular rotating block 73 is not in contact with the ball bearing 6, the cooling water enters the central channel 1 through the connecting hole 5 and the water distribution hole 52. Under the action of high-speed, high-pressure airflow, it is initially atomized and then enters the first venturi tube 8. The throat of tube 8 undergoes a second atomization, then enters the conical hole 92 and nozzle 93 through the distribution chamber 91, undergoes a third atomization through the second Venturi tube formed by the conical hole 92 and nozzle 93, and is finally sprayed onto the surface of the blister board to cool it. As it rotates, the protrusion 74 on the annular rotating block 73 contacts and squeezes the ball 6, causing the ball 6 to move axially to fit the conical surface of the connecting hole 5, cutting off the connection between the annular flow channel 3 and the central flow channel 1. The gas is then sprayed out through the nozzle 93 to cool the blister board, while simultaneously breaking and dispersing the water film layer formed on the blister board, allowing the water mist of the next cycle to continue to directly contact the surface of the blister board.

[0044] The protrusion 74 periodically squeezes the ball 6 to move it axially and forms a seal with the conical sealing surface 51, cutting off the connection between the annular flow channel 3 and the central flow channel 1, forming water mist-airflow alternating cooling, avoiding the formation of a stable and continuous water film layer on the surface of the thermoformed board, improving heat exchange efficiency and accelerating the cooling efficiency of the thermoformed board.

[0045] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A rapid cooling device for processing blister trays, characterized in that, Includes a dual-channel water mist cooling nozzle positioned directly above the mold (10) of the vacuum forming machine, the dual-channel water mist cooling nozzle comprising: The central flow channel (1) is used to transport high-pressure gas; An annular flow channel (3) is coaxially arranged around the outside of the central flow channel (1) for conveying cooling water; A connecting hole (5) is evenly opened along the circumference of the side wall of the central flow channel (1). A conical sealing surface (51) is provided near the inner wall of the central flow channel (1) of the connecting hole (5). A ball bearing (6) is movably arranged near the conical sealing surface (51). Impeller assembly (7) is disposed inside the central flow channel (1) and includes an impeller (72) coaxially disposed with the central flow channel (1) and an annular rotating block (73) driven therefrom. The annular rotating block (73) has evenly distributed protrusions (74) on its outer circumference. When the impeller (72) is driven to rotate by the airflow, the protrusion (74) periodically squeezes the ball (6) to make it move axially and form a seal with the conical sealing surface (51), cutting off the communication between the annular flow channel (3) and the central flow channel (1).

2. The rapid cooling device for processing blister trays according to claim 1, characterized in that, The outlet end of the central flow channel (1) is fixedly connected to the first venturi tube (8).

3. A rapid cooling device for processing blister trays according to claim 2, characterized in that, The first venturi tube (8) has a detachable nozzle assembly (9) at its outlet end.

4. A rapid cooling device for processing blister trays according to claim 3, characterized in that, The nozzle assembly (9) includes a distribution cavity (91), and a plurality of tapered holes (92) are opened on the end face of the distribution cavity (91). The tapered holes (92) are fixedly connected to the nozzle (93), and the nozzle (93) and the tapered holes (92) form a second Venturi tube.

5. A rapid cooling device for processing blister trays according to claim 1, characterized in that, A water distribution hole (52) is formed around the connecting hole (5), and the water distribution hole (52) is inclined and connected to the connecting hole (5).

6. A rapid cooling device for processing blister trays according to claim 1, characterized in that, The number of the protrusions (74) distributed circumferentially is an integer multiple of the number of the connecting holes (5), and the working surface of the protrusions (74) is provided with a polytetrafluoroethylene wear-resistant layer.

7. A rapid cooling device for processing blister trays according to claim 1, characterized in that, The dual-channel water mist cooling nozzle is connected to the vacuum forming machine via a linear actuator.

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