Defoaming device for vacuum drying of traditional Chinese medicine extract

Abstract

The invention relates to the technical field of traditional Chinese medicine extract drying, and discloses a defoaming device for vacuum drying of traditional Chinese medicine extracts.The defoaming device comprises a vacuum drying box and a material tray, a storage rack is fixedly installed in the vacuum drying box, a plurality of heating plates are fixedly installed in the storage rack, and the material tray is placed on the upper surfaces of the heating plates; the middle area of the bottom surface of the tray is in contact with the upper surface of the heating plate, and a certain gap is kept between the peripheral area of the bottom surface of the tray and the upper surface of the heating plate. The structure of the heating plate is improved, the bottom heating surface of the tray is adjusted, and the periphery of the bottom of the tray is not in contact with a heat source, so that temperature difference is formed between the middle and the periphery of a material in the tray, the liquid level of the middle material is raised due to a boiling state, the material is forced to flow to the low liquid level of the periphery, and the transverse fluidity in the drying process is enhanced; therefore, foam accumulation is reduced, evaporation of moisture of the materials is accelerated, the materials are prevented from overflowing due to continuous accumulation of the foam, and the effects of defoaming and overflowing prevention are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of drying traditional Chinese medicine extracts, and in particular to a defoaming device used for vacuum drying of traditional Chinese medicine extracts. Background Art

[0002] Characteristics of Chinese medicine extracts: There are many types, and the basic commonalities are: fluidity, high viscosity, complex composition of viscous substances, and obvious changes in viscosity with temperature and concentration; the existing static vacuum drying oven drying forms: ordinary vacuum drying ovens and pulsating vacuum drying ovens. This type of equipment is mostly chemical and pharmaceutical raw material drying equipment. Because chemical products are mostly salt-forming crystals, there are no complex component characteristics, and there is no foam or very little foam during the drying process, so the drying process is stable and is widely used.

[0003] Working principle of vacuum drying oven in prior art: the main heat conduction medium for vacuum drying of extract is solid tray and liquid extract. As the moisture content decreases during the drying process, fluidity decreases, and heat conduction of the foam surface is blocked due to sticky substances and foam formation. The foam surface cools down rapidly, and fluidity decreases accordingly, while viscosity increases. The foam continues to increase or become larger. When the amount of foam generated far exceeds the amount of foam rupture, the extract overflows, resulting in material waste and pollution. For example, in the prior art, a patent document with announcement number CN220567688U discloses a pulse-type defoaming and bubble-breaking internal and external heating vacuum drying oven. The gas or hot air flow blown out by the pulse tube can blow through the bubbles generated by the gas discharged during the material drying process, thereby achieving the function of defoaming and bubble breaking. However, the actual use effect is not ideal. Moreover, under a vacuum environment, a large amount of gas enters the drying oven, destroying the stable negative pressure and thus affecting the evaporation of moisture in the material.

[0004] In the industrial production of Chinese herbal medicine extract powder, the current domestic defoaming solutions are: ultrasonic heating can make the material heated evenly and the foam controllable, but it is difficult to pass changes because it is used in drug production risk assessment and cannot be widely used; the current defoaming in the extract drying process mostly uses air or hot air blowing and pulsating vacuum, and the on-site effect can only solve less than 30% of the types of Chinese herbal medicine extracts. As for the best vacuum drying equipment currently available, after material testing, if you want to ensure that the extract does not overflow during the drying process, you can only reduce the amount of material loaded or slowly heat to significantly increase the drying time. No company can accept this ultra-low efficiency solution.

[0005] Based on this, there is a problem of difficulty in defoaming during the vacuum drying process of traditional Chinese medicine extracts, which seriously affects production efficiency and needs to be solved urgently. Summary of the invention

[0006] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a defoaming device for vacuum drying of traditional Chinese medicine extracts.

[0007] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a defoaming device for vacuum drying of traditional Chinese medicine extract, comprising a vacuum drying oven and a material tray, a storage rack is fixedly installed in the vacuum drying oven, a plurality of heating plates are fixedly installed in the storage rack, the material tray is placed on the upper surface of the heating plate, the middle area of ​​the bottom surface of the material tray is in contact with the upper surface of the heating plate, and the surrounding area of ​​the bottom surface of the material tray maintains a certain gap with the upper surface of the heating plate, and is in a suspended state.

[0008] Preferably, a heightening plate is welded to the upper surface of the heating plate, the area of ​​the heightening plate is smaller than the bottom area of ​​the tray, and a plurality of positioning corner blocks are fixedly installed on the upper surface of the heating plate. The bottom of the tray is not in contact with the heat source, so that a temperature difference is formed between the middle and surrounding parts of the material in the tray. The liquid level of the material in the middle is raised due to the boiling state, and the material is forced to flow to the low liquid level around it. The lateral fluidity is enhanced during the drying process, thereby reducing the accumulation of foam.

[0009] Preferably, a bubble breaking component is fixedly installed inside the rack, and the bubble breaking component includes a perforated plate and an infrared heating tube. The perforated plate is fixedly connected to the rack, and the infrared heating tube is fixedly installed on the upper side of the perforated plate. After the material tray is placed on the upper surface of the heating plate, the perforated plate is located on the upper side of the material tray, and the infrared heating tube heats the upper surface of the material in the material tray to enhance the upper and lower fluidity of the material at the end of the drying process.

[0010] Among them, a plurality of through holes are opened on the surface of the orifice plate, and a plurality of reflecting plates are fixedly installed on the upper surface of the orifice plate, and the reflecting plates cover the upper side of the perforations. The infrared heating tube is arranged in the inner cavity of the reflecting plate. The thermal radiation energy of the infrared heating tube is irradiated on the surface of the extract bubble in the form of a point light source, thereby improving the bubble breaking speed.

[0011] Preferably, a heat pipe is fixedly installed in the heating plate, and the heat of the heat pipe is transferred through the heat of the heating plate to heat the material tray and the material inside it.

[0012] The present invention has the following beneficial effects:

[0013] 1. The present invention improves the structure of the heating plate and adjusts the heating surface of the bottom plate of the material tray. The bottom of the material tray is not in contact with the heat source. The purpose is to form a temperature difference between the middle and surrounding parts of the material in the material tray. The liquid level of the middle material is raised due to the boiling state, and the material is forced to flow to the low liquid level around. The lateral fluidity during the drying process is enhanced, thereby reducing the accumulation of foam, accelerating the evaporation of material moisture, and preventing the material from overflowing due to the continuous accumulation of foam, thereby achieving the effect of defoaming and preventing overflow.

[0014] 2. The present invention sets a radiation heating source above the material tray to form a local heat source distribution on the surface of the material, avoiding contact between the heating source and the material, reducing material loss and avoiding material pollution. The principle is to radiate the bubble material with appropriate infrared temperature so that the bubbles formed by it burst quickly due to the interference of thermal infrared, thereby reducing the accumulation of foam.

[0015] 3. The present invention sets a perforated plate, and infrared rays pass through the perforations to concentrate the heat radiation energy locally on the material. The material steam drum is heated and quickly "punctured" by infrared rays to exhaust gas, thereby inhibiting the growth of bubbles, similar to the method of puncturing a balloon, achieving "defoaming" and increasing the defoaming speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the three-dimensional structure of a defoaming device for vacuum drying of traditional Chinese medicine extracts proposed by the present invention (I);

[0017] Figure 2 A schematic diagram of the three-dimensional structure of a defoaming device for vacuum drying of traditional Chinese medicine extracts proposed by the present invention (II);

[0018] Figure 3 This is a schematic diagram of the three-dimensional structure of the storage rack proposed by the present invention;

[0019] Figure 4 This is a schematic diagram of the top view of the heating plate proposed by the present invention;

[0020] Figure 5 This is a schematic diagram of the cross-sectional structure of the material tray proposed in the present invention (a schematic diagram of defoaming during the extract drying process);

[0021] Figure 6 Schematic diagram of defoaming without infrared assistance during atmospheric pressure extract drying process;

[0022] Figure 7 Schematic diagram of infrared-assisted defoaming in atmospheric pressure extract drying process;

[0023] Figure 8 This is a schematic diagram of defoaming in the extract drying process before the heating plate structure is improved;

[0024] Fig. 9 Schematic diagram of defoaming in the extract drying process after the heating plate structure is improved.

[0025] In the figure: 1 vacuum drying oven, 2 material tray, 3 storage rack, 4 heating plate, 5 heightening plate, 6 hole plate, 7 infrared heating tube, 8 perforation, 9 reflection plate, 10 heat conducting tube, 11 extract surface, 12 positioning corner block. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0027] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0028] Reference Figure 1-9 A defoaming device for vacuum drying of traditional Chinese medicine extracts comprises a vacuum drying oven 1 and a material tray 2. A rack 3 is fixedly installed in the vacuum drying oven 1. A plurality of heating plates 4 are fixedly installed in the rack 3. The material tray 2 is placed on the upper surface of the heating plate 4. The middle area of ​​the bottom surface of the material tray 2 contacts the upper surface of the heating plate 4. The surrounding area of ​​the bottom surface of the material tray 2 maintains a certain gap with the upper surface of the heating plate 4, and is in a suspended state.

[0029] Among them, a heat pipe 10 is fixedly installed in the heating plate 4, and the heat pipe 10 can heat the heating plate 4 by electric heating or steam heating. It should be noted that the vacuum drying box 1 is a conventional equipment in the prior art and will not be described in detail here.

[0030] In this embodiment, a heightening plate 5 is welded on the upper surface of the heating plate 4, the area of ​​the heightening plate 5 is smaller than the bottom area of ​​the material tray 2, a plurality of positioning angle blocks 12 are fixedly installed on the upper surface of the heating plate 4, the material tray 2 is made of 304 stainless steel, the heightening plate 5 is laser welded on the upper surface of the heating plate 4, the inner cavity of the material tray 2 is mirror polished, and after the material is filled in the material tray 2, it is placed on the upper side of the heightening plate 5, such as Figure 4 shown.

[0031] In this embodiment, reference Figure 3 A bubble breaking component is fixedly installed inside the rack 3, and the bubble breaking component includes a perforated plate 6 and an infrared heating tube 7. The perforated plate 6 is fixedly connected to the rack 3, and the infrared heating tube 7 is fixedly installed on the upper side of the perforated plate 6. After the material tray 2 is placed on the upper surface of the heating plate 4, the perforated plate 6 is located on the upper side of the material tray 2.

[0032] The surface of the orifice plate 6 is provided with a plurality of through holes 8 , and a plurality of reflective plates 9 are fixedly mounted on the upper surface of the orifice plate 6 . The reflective plates 9 cover the upper sides of the through holes 8 , and the infrared heating tubes 7 are arranged in the inner cavities of the reflective plates 9 .

[0033] A 600mm×400mm×50mm (depth) tray was used to test the extract drying (using a conventional vacuum dryer). The material filling height was 40mm. The material dynamics during the heating process were described in three defined stages. Under normal operation, overflow occurred in stages 1, 2, and 3 when the heating power was controlled, and it was extremely difficult to control the amount of extract foam.

[0034] Experiment on drying process when changing the structure of heating plate 4 and adding infrared foam breaking components: After the test, the extract was dried under normal pressure, and the amount of foam was manually controlled by adjusting the power of the infrared heating tube to achieve no foam or a small amount of foam for the purpose of heating power control. In order to facilitate the analysis of the problem points in the drying process of the extract material, according to the obvious changes in the material state, it is artificially divided into three stages according to time:

[0035] 1. In the first stage, the material evaporates when the density is low, the heat power is large, the evaporation effect is good, the foam is easy to control, and the fluidity is excellent;

[0036] 2. In the second stage, the moisture of the material has evaporated in large quantities. By controlling the appropriate heating power, the foam can still be well controlled. The problem of material overflow is concentrated on the adjustment of the heating amount. Improper adjustment will produce a large amount of foam that has no time to dissipate, and the material liquid level will rise and overflow. The visual fluidity is very good. By adjusting the heating temperature, the amount of foam can be well controlled to prevent overflow.

[0037] 3. In the third stage, the liquid flows slowly. As the water evaporates continuously, the viscosity is high, the foam is not easy to dissipate, the convection speed slows down, the foam accumulates and merges, and the foam persists and does not break, which seriously affects the evaporation and drying of the material. By adjusting the infrared heating power, the infrared rays pass through the perforation 8 to locally heat the persistent foam, forming a puncture effect. After the foam breaks, a large amount of water vapor is continuously vacuumed away, and the drying speed is significantly improved.

[0038] Experimental summary:

[0039] 1. Traditional heating method: foam covers the entire liquid surface (see attached Figure 8 ), the foam is not easy to dissipate during the heating process. Only the middle of the extract tray 2 is directly heated, for example, the 5 cm around the tray 2 is not directly in contact with the heat source. In the three stages of the heating process, the liquid level in the middle of the material is raised due to the increase in internal foam. When the material fluidity is low, a height difference of the liquid level occurs. The height difference of the liquid level forces the flow direction of the viscous material to change, thereby increasing the flow speed, accelerating the heat exchange of the material, and significantly reducing the foam (see attached Fig. 9 ).

[0040] 2. In the third stage, the material has high viscosity and poor fluidity. The heat conduction and convection of the material are weakened. The water at the bottom of the material evaporates quickly to form bubbles wrapped in water vapor. The bubbles move up slowly and then merge multiple bubbles to form large bubbles (such as attached Figure 6As shown in the figure, the temperature difference between the bottom and the top of the material is limited due to the flow, the temperature of the upper material is lower and viscous, forming bubbles that are difficult to break, which seriously affects the evaporation of water and reduces the drying efficiency, which is also the main reason for the overflow of the material.

[0041] 3. In the third stage, infrared radiation is added. When appropriate infrared heats the surface of the material locally, coupled with the infrared's penetrability under vacuum, the material on the upper part of the material is heated, especially the deep heating, its viscosity is weakened, the bubble retention time is reduced, and the bubble accumulation is reduced (such as attached Figure 7 As shown in the figure, the material liquid level increases only slightly, the bubble maintenance time decreases, the water evaporation amount increases, the required drying time is shortened, and the efficiency is significantly improved.

[0042] In summary, the defoaming device for vacuum drying of Chinese medicine extracts proposed by the present invention improves the structure of the heating plate 4, adjusts the heating surface at the bottom of the tray 2, and the bottom of the tray 2 is not in contact with the heat source. The purpose is to form a temperature difference between the middle and the surrounding of the material in the tray 2. The liquid level of the middle material is raised due to the boiling state, and the material on the extract surface 11 is forced to flow to the low liquid level around, and the lateral fluidity is enhanced during the drying process (such as Figure 5 As shown), the accumulation of foam is reduced, the evaporation of material moisture is accelerated, and the material is prevented from overflowing due to the continuous accumulation of foam, thereby achieving the effect of defoaming and preventing overflow; a radiation heating source (infrared heating tube 7) is arranged above the material tray 2, and a local heat source distribution is formed on the surface of the material to avoid contact between the heating source and the material, reduce material loss and avoid material pollution. The principle is that the appropriate infrared temperature radiates the bubble material so that the bubbles formed by it are quickly dissipated due to the interference of the thermal infrared, enhance its upward and downward fluidity at the end of the drying process, accelerate the heat exchange efficiency, reduce the accumulation of foam, and the thermal radiation heat energy of the infrared heating tube 7 is irradiated on the surface of the extract bubble in the form of a point light source, so that the local surface of the extract bubble is quickly heated, the heat fluidity of the extract bubble is enhanced, the bubble is quickly broken and exhausted, the bubble body is inhibited from increasing, and the defoaming speed is increased.

[0043] In industrial applications, the structure of the material tray 2 can be adjusted to raise the middle part that contacts the heating source so that the material tray 2 is suspended on all sides, or the structure of the heating source can be improved so that the material tray 2 is not heated on all sides. This can also achieve a temperature difference in the material in the tray, thereby enhancing its lateral fluidity and thereby eliminating bubbles and preventing overflow.

[0044] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A defoaming device for vacuum drying of Chinese medicine extract, comprising a vacuum drying oven (1) and a material tray (2), characterized in that: A storage rack (3) is fixedly installed in the vacuum drying box (1), and a plurality of heating plates (4) are fixedly installed in the storage rack (3). The material tray (2) is placed on the upper surface of the heating plate (4), and the middle area of ​​the bottom surface of the material tray (2) is in contact with the upper surface of the heating plate (4). The surrounding area of ​​the bottom surface of the material tray (2) maintains a certain gap with the upper surface of the heating plate (4), and is in a suspended state.

2. A defoaming device for vacuum drying of Chinese medicine extract according to claim 1, characterized in that: A heightening plate (5) is welded to the upper surface of the heating plate (4), the area of ​​the heightening plate (5) is smaller than the bottom area of ​​the material tray (2), and a plurality of positioning corner blocks (12) are fixedly mounted on the upper surface of the heating plate (4).

3. A defoaming device for vacuum drying of Chinese medicine extract according to claim 2, characterized in that: A foam breaking assembly is fixedly installed inside the storage rack (3), and the foam breaking assembly comprises a perforated plate (6) and an infrared heating tube (7). The perforated plate (6) is fixedly connected to the storage rack (3), and the infrared heating tube (7) is fixedly installed on the upper side of the perforated plate (6). After the material tray (2) is placed on the upper surface of the heating plate (4), the perforated plate (6) is located on the upper side of the material tray (2).

4. A defoaming device for vacuum drying of Chinese medicine extract according to claim 3, characterized in that: The surface of the orifice plate (6) is provided with a plurality of through holes (8), and a plurality of reflecting plates (9) are fixedly mounted on the upper surface of the orifice plate (6). The reflecting plates (9) cover the upper sides of the through holes (8), and the infrared heating tubes (7) are arranged in the inner cavity of the reflecting plates (9).

5. A defoaming device for vacuum drying of Chinese medicine extract according to claim 4, characterized in that: A heat conducting pipe (10) is fixedly installed inside the heating plate (4).

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