Vacuum dryer that does not require a vacuum pump

Abstract

A vacuum dryer that does not require a vacuum pump according to an embodiment of the present invention includes a drying chamber having a drying table and an exhaust valve on the outside of one side that communicates with the inside; a steam generator located outside the drying chamber, having a water tank, and connected to a steam inlet; a condenser provided in a high-temperature region; a first heat exchanger connected to the condenser outside the drying chamber; an evaporator provided in a low-temperature region; a second heat exchanger connected to the evaporator outside the drying chamber; a compressor connecting the first heat exchanger and the second heat exchanger; and a heat pump provided in conjunction with the inside and outside of the drying chamber, the heat pump including an expansion valve connecting the condenser and the evaporator.

Description

Technical Field

[0001] The present invention relates to a vacuum dryer that does not require a vacuum pump. After saturating the inside of the drying chamber with water vapor, the volume rapidly decreases during the process of lowering the temperature and causing the water vapor to undergo a phase transition to a liquid, and a mechanism is utilized to form a vacuum inside the drying chamber, and it relates to an apparatus that can perform vacuum drying without using a vacuum pump, a heater, and a heat medium.

[0002] More specifically, the vacuum dryer of the present invention that does not require a vacuum pump is provided with a condenser that forms a high-temperature region and an evaporator that forms a low-temperature region interconnected inside a drying chamber having a sealed shape. The condenser and the evaporator are respectively connected to a first heat exchanger and a second heat exchanger, and the first heat exchanger and the second heat exchanger are connected to a compressor so that the heat exchange capacity can be varied. A steam generator is provided outside the drying chamber so that water vapor can be supplied to the inside of the drying chamber.

[0003] After loading an object to be dried inside the drying chamber, injecting water vapor into the drying chamber, and saturating the inside of the drying chamber with water vapor by discharging air with an interlocking exhaust valve, the heat pump is driven with the heat exchange capacity of the first heat exchanger set to the maximum value to release the heat of the first heat exchanger to the outside of the drying chamber. At the same time, the inside of the drying chamber is cooled at the decreasing temperature of the condenser, and the water vapor undergoes a phase transition to water or ice in the evaporator, and the pressure decreases to reach a vacuum state. Then, the heat exchange capacity of the first heat exchanger is reduced to supply heat to the condenser to form a high-temperature region and dry the object to be dried. In the evaporator, the water vapor liquefies or sublimes to form a low-temperature region, and by maintaining the vacuum state inside the drying chamber, it relates to a vacuum dryer that does not require a vacuum pump and can perform vacuum low-temperature drying to produce high-quality dried products.

Background Art

[0004] The history of food drying dates back to a time as far back as the history of humanity. Drying (Disiccation) is defined as an operation to remove the moisture contained in a substance. Drying has the purpose of improving the storability of the object to be dried, facilitating handling and transportation, and increasing its value. Drying can be regarded as one of the processing means or processing steps to achieve such purposes.

[0005] There are various drying methods. Typical ones include airflow drying where hot air is applied to the object to be dried, radiation drying where infrared rays or the like are irradiated in the case of objects to be dried that are prone to scattering such as powders, dehumidification drying where the object to be dried is placed in a dryer containing a desiccant such as concentrated sulfuric acid or silica gel in the case of objects to be dried that should be dried at low temperatures, vacuum drying where the inside of the dryer is evacuated to make it easier for the moisture in the object to be dried to evaporate, and further, freeze-drying where the object to be dried is frozen and dried in the case of objects to be dried that are easily decomposed by heat or prone to deterioration at normal temperature, and vacuum freeze-drying where the inside of the frozen dryer is evacuated to directly sublimate and remove the ice in the object to be dried in order to increase the drying speed, etc.

[0006] Even for the same food, its quality changes depending on the drying method applied. Until now, technology has been improved according to traditional experiential drying methods of wind (blowing), humidity (dehumidification), and temperature (heating), but recently, next-generation integrated dryers based on basic technologies such as conduction, convection, radiation, and pressure have been actively researched and sold.

[0007] In the case of food, the lower the drying temperature and the shorter the drying time, the better the quality of the dried food. However, the lower the drying temperature, the longer the drying time, which is accompanied by a quality decline. For example, in the case of drying chili peppers, except for sun-dried chili peppers, usually, drying is carried out in a chili pepper dryer at around 55°C for about 40 hours (about 2 days). If the drying temperature is lowered to 35°C under the same conditions, the drying time will be extended to around 160 hours (about 7 days). In this case, the appearance of the dried chili peppers is very good, but when the chili peppers are cut, it can be seen that the inside is full of mold and is unusable as food. That is, as drying progresses, deterioration also progresses. In Korea, there used to be shade-dried chili peppers that were dried in a well-ventilated shaded area and were of better quality than sun-dried chili peppers (sun-dried), but due to the difficult drying method, long time required, and low yield, they are no longer seen now.

[0008] In the case of livestock and seafood products, which are more perishable than agricultural products, drying is even more difficult. This is also the reason why, until now, there were only methods such as removing internal organs or blanching through primary processing before drying, or drying in winter to maintain quality. To overcome this, methods such as salting using salt and smoking using hot smoke have been developed and have come to be developed.

[0009] Currently, although there are vacuum freeze-dryers that solve the above problems, due to the high price of the equipment itself, the complexity of operation, and the high operating costs required for drying, they are only used for pharmaceuticals and high-end foods. In the case of general foods, it is difficult to apply due to the price increase of dried products.

[0010] Dryers are typical energy-consuming equipment, and most of the energy used is consumed as the heat of vaporization, that is, latent heat, for moisture evaporation in the drying process and is released into the atmosphere and wasted. Recent energy-saving dryers save energy by recovering and reusing the latent heat of water vapor discarded into the atmosphere with a heat pump.

[0011] To improve dryers, various technologies that pursue energy-saving technologies, improvement of drying efficiency and drying quality have been proposed and developed. In food drying, if food is rapidly frozen and then dried using the sublimation phenomenon, the food can be dried with the highest quality. Therefore, technologies such as low-pressure drying, vacuum drying, vacuum freeze-drying, and vacuum heating drying have been continuously developed and improved by applying this method. In order to improve the quality of dried foods, it is necessary to achieve a high drying speed at a low temperature. Therefore, dryers in this field generally have an almost similar configuration with essential elements such as a drying chamber for storing the material to be dried, a vacuum pump section, a rapid freezing section, a heater, and a heat medium section.

Prior Art Documents

Patent Documents

[0012]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0013] Conventional vacuum dryers have a vacuum pump for maintaining the vacuum inside the dryer, a heater for supplying drying heat to the material to be dried, and a heat medium section. Since the configuration of the dryer becomes complicated, there are disadvantages such as high price and high operating cost of the dryer.

[0014] The present invention was created to solve the above-mentioned problems in the prior art. After saturating the inside of the drying chamber with water vapor, the temperature is lowered to cause the water vapor to undergo a phase transition to a liquid, during which the volume rapidly decreases, and a mechanism is utilized to form a vacuum inside the drying chamber so that vacuum drying can be performed without a vacuum pump. The object is to provide a vacuum pump-free vacuum dryer that can create a vacuum state in the drying chamber.

[0015] The present invention is provided with a condenser that forms a high-temperature region and an evaporator that forms a low-temperature region interconnected inside a drying chamber. The condenser and the evaporator are respectively connected to a first heat exchanger and a second heat exchanger. The first heat exchanger and the second heat exchanger are connected to a compressor so that the heat exchange capacity can be varied. A steam generator is provided outside the drying chamber so that water vapor can be supplied into the drying chamber.

[0016] After loading an object to be dried inside the drying chamber and injecting and saturating the drying chamber with water vapor, the heat pump is driven with the heat exchange capacity of the first heat exchanger set to the maximum value to release the heat of the first heat exchanger outside the drying chamber. At the same time, the inside of the drying chamber is cooled at the decreasing temperature of the condenser, and a phase transition of water vapor to water or ice occurs in the evaporator, and the pressure decreases to reach a vacuum state. After that, the heat exchange capacity of the first heat exchanger is reduced to supply heat to the condenser to form a high-temperature region to dry the object to be dried. In the evaporator, water vapor liquefies or sublimes to form a low-temperature region, and the vacuum state inside the drying chamber is maintained so that the object to be dried is dried in a vacuum state. The purpose is to provide a device that can construct and drive a vacuum dryer without using a vacuum pump, a heater, and a heat medium, which have been essential elements of vacuum dryers until now.

[0017] The above objects and various advantages of the present invention will become more apparent to those skilled in the art from the preferred embodiments of the present invention.

Means for Solving the Problems

[0018] The present invention is for achieving the above object.

[0019] The vacuum dryer according to an embodiment of the present invention forms a sealed internal space, is provided with a drying table inside, has a steam inlet linked to an exhaust valve provided on one inner side, and is provided with an exhaust valve linked to the steam inlet on the outside of the other side. It includes a drying chamber, a steam generator located outside the drying chamber and equipped with a water tank and connected to the steam inlet, and a heat pump provided in conjunction with the inside and outside of the drying chamber to form a high-temperature region and a low-temperature region inside the drying chamber. When the steam generator saturates the inside of the drying chamber with water vapor, the heat pump is characterized by including forming a vacuum state by lowering the temperature inside the drying chamber to liquefy or sublimate the water vapor and reduce the volume.

[0020] According to one embodiment, the heat pump further includes a condenser provided in the high-temperature region, a first heat exchanger connected to the condenser outside the drying chamber, an evaporator provided in the low-temperature region, a second heat exchanger connected to the evaporator outside the drying chamber, a compressor connecting the first heat exchanger and the second heat exchanger, and an expansion valve connecting the condenser and the evaporator.

[0021] According to one embodiment, it further includes a conical cyclone configured in a shape surrounded by the evaporator, a blower inserted and mounted in a cylindrical portion at one end of the cyclone, and a motor mounted on the upper end of the blower. The cyclone has an internal space formed and connected from a tubular suction port provided in the cylindrical portion at one end to the conical portion at the other end. The blower is provided with an exhaust port on the side, and the lower end is connected to the inside of the cyclone. It is further included that the blowing generated by the motor is configured to communicate with the exhaust port and the conical portion.

[0022] According to one embodiment, it further includes a storage tank connected to the conical portion of the cyclone. The storage tank is connected to a discharge pump outside the drying chamber, and the discharge pump is connected to the water tank by a pipe. Water vapor generated in the high-temperature region of the drying chamber is condensed by the cyclone and discharged in the form of water or ice, forming a circulation structure in which it is recovered by the storage tank.

[0023] According to one embodiment, it further includes a check valve at the part where the storage tank and the discharge pump are connected outside the drying chamber to prevent the condensate in the storage tank from flowing back into the storage tank.

[0024] Specific matters of other embodiments are included in the detailed description and the drawings.

Advantages of the Invention

[0025] According to the vacuum dryer that does not require a vacuum pump of the present invention, the following effects can be obtained.

[0026] First, after saturating the inside of the drying chamber with water vapor, by using a mechanism that allows a vacuum to be formed inside the drying chamber while the volume rapidly decreases during the process of lowering the temperature and causing the water vapor to undergo a phase transition to a liquid, vacuum drying can be performed with the drying chamber in a vacuum state without using a vacuum pump, a heater, or a heat medium.

[0027] Second, since direct heat exchange is performed inside the drying chamber without using a vacuum pump, a heater, or a heat medium, which are essential elements of a vacuum dryer, the structure of the dryer becomes very simple, and the durability and reliability of the dryer are improved.

[0028] Third, due to the characteristics of this vacuum dryer that operates only by driving a heat pump, the failure rate is significantly lower compared to conventional complex vacuum freeze dryers, and maintenance becomes easier.

[0029] Fourth, since the price of the dryer is reduced and the drying cost of food is also reduced, general foods that were difficult to use due to the price and operating cost of the dryer can now be dried with high quality using this dryer, and the dried food culture in Korea can be fundamentally upgraded by one level.

[0030] Fifthly, in addition to saving the driving energy of the vacuum pump, due to the high coefficient of performance of the heat pump and the fact that the heat of the heat pump circulates solely through heat generation (drying) and heat absorption (condensation) inside the drying chamber, no energy loss other than drying occurs, and the energy efficiency is extremely high. That is, since all heat transfer involved in drying is not lost to the outside within the drying chamber, very high-efficiency energy conservation is achieved.

[0031] Sixthly, throughout the entire drying process, since the material to be dried is sealed from the outside, clean drying without contamination by external substances such as PM2.5 is carried out.

[0032] Seventhly, this enables the simplification of the system and energy conservation, allowing the launch of a competitive dryer in the market and fundamentally upgrading the Korean dried food culture by one level.

Brief Description of the Drawings

[0033]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0034] To fully understand the present invention, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

[0035] In the description of the present invention, the following specific structural or functional descriptions are merely exemplified for explaining embodiments according to the concept of the present invention. Embodiments according to the concept of the present invention may be implemented in various forms and should not be construed as being limited to the embodiments described in detail below.

[0036] In addition, the embodiments according to the concept of the present invention may be subject to various modifications and may have various forms. Therefore, specific embodiments are illustrated in the drawings and described in detail herein.

[0037] However, this does not limit the embodiments according to the concept of the present invention to a specific disclosed form, and it should be understood to include modifications, equivalents, or alternatives included in the spirit and technical scope of the present invention.

[0038] This embodiment is provided to more fully explain the present invention to those having average knowledge in the art. Therefore, the shapes of elements in the drawings may be exaggerated for clearer illustration.

[0039] Note that in each drawing, the same members may be denoted by the same reference numerals. A detailed description of known functions and configurations that are determined to unnecessarily obscure the gist of the present invention is omitted.

[0040] FIG. 1 is a schematic configuration diagram of a vacuum dryer that does not require a vacuum pump according to an embodiment of the present invention, FIG. 2 is a configuration diagram of a vacuum dryer that does not require a vacuum pump according to another embodiment of the present invention, and FIG. 3 is a state change curve of water according to pressure and temperature, which is the principle applied to the vacuum dryer that does not require a vacuum pump according to the embodiment of the present invention.

[0041] A vacuum dryer 10 that does not require a vacuum pump according to a preferred embodiment of the present invention includes a drying chamber 200, a heat pump 100, and a steam generator 300.

[0042] The drying chamber 200 is in the form of a case that forms a sealed internal space and can function as a space for arranging and drying an object to be dried.

[0043] The interior of the drying chamber 200 may be divided and set into a high-temperature region 220 and a low-temperature region 230, which is not an artificial partition by a device or component, but can be identified as a space divided by the function driven by the heat pump 100.

[0044] When visually observing the drying chamber 200 from the side, a steam inlet 210 may be provided at the lower end of the drying chamber 200, and an exhaust valve 211 may be provided at the upper end.

[0045] At this time, the positions of the steam inlet 210 and the exhaust valve 211 may be configured at any position as long as it is suitable for optimizing the function of the present invention.

[0046] The steam generator 300 provided outside the drying chamber 200 can be connected to the inside of the drying chamber 200 through the steam inlet 210 at the lower end of the drying chamber 200.

[0047] When the steam generator 300 generates water vapor and supplies the water vapor to the inside of the drying chamber 200 through the steam inlet 210, the drying chamber 200 is filled with water vapor. At this time, by adjusting the opening and closing of the exhaust valve 211, the function of discharging or sealing the air and water vapor inside the drying chamber 200 can be achieved.

[0048] A water tank 310 may be connected to the steam generator 300 to generate water vapor, and a drain 311 may be attached to the water tank 310 to allow water to be injected and discharged.

[0049] The exhaust valve 211 is provided outside the upper end of the drying chamber 200 and functions to discharge or block the air or water vapor inside the drying chamber 200. An exhaust check valve 212 may be provided at the lower end of the exhaust valve 211 to prevent external air from flowing back into the inside of the drying chamber 200.

[0050] At this time, the exhaust valve 211 and the exhaust check valve 212 are connected vertically, but the exhaust valve 211 is provided outside the upper end of the drying chamber 200, and the exhaust check valve 212 has a shape provided inside the upper end of the drying chamber 200.

[0051] The drying chamber 200 is provided with a drying table 213 inside to spread the object to be dried.

[0052] The drying table 213 may be provided in the form of a wire net through which hot air and air pass or an iron plate with excellent conductivity, and can be located in the high-temperature region 220 inside the drying chamber 200 to maximize the drying effect. Specifically, it is preferably located above the condenser 110 of the heat pump 100 described later and is provided so as to be directly exposed to the heat and high temperature dissipated from the condenser 110.

[0053] The drying table 213 may be composed of a single layer or multiple layers, and its shape and number of layers can be variably designed and applied according to the shape of the entire drying chamber 200 and the installation location and usage of the dryer.

[0054] The drying chamber 200 may be provided with a lid. As a preferred embodiment of the present invention, the lid can be located at the upper end of the drying chamber 200.

[0055] The lid of the drying chamber 200 can be opened to load or remove the object to be dried, and the devices located inside the drying chamber 200 can be inspected or repaired.

[0056] When the lid is attached to the drying chamber 200, a sealed state can be formed, and the sealed drying chamber 200 can have a structure that communicates with the outside through the steam inlet 210 and the exhaust valve 211.

[0057] The heat pump 100 may be provided in conjunction with the inside and outside of the drying chamber 200.

[0058] After evacuating the inside of the drying chamber 200, the heat pump 100 can perform the core function of maintaining an environment in which the object to be dried can be dried in a vacuum state by drying the object to be dried and maintaining a heat circulation and a heat balance state.

[0059] Therefore, the heat pump 100 may include a condenser 110, an evaporator 120, an expansion valve 140, a compressor 130, a first heat exchanger 131, and a second heat exchanger 132.

[0060] The condenser 110, the evaporator 120, and the expansion valve 140 may be located inside the drying chamber 200, and the compressor 130, the first heat exchanger 131, and the second heat exchanger 132 may be located outside the drying chamber 200.

[0061] The condenser 110 may be located in the high-temperature region 220 inside the drying chamber 200 and may be connected to the first heat exchanger 131.

[0062] The condenser 110 serves to condense the refrigerant and dry the object to be dried. Therefore, it may be formed in any form and at any position. However, according to a preferred embodiment of the present invention, it is in a pipe shape and is wound round like a coil in the high-temperature region 220 and can be located below the drying table 213.

[0063] One end of the condenser 110 may be connected to the first heat exchanger 131 in a pipe shape, and the other end may be connected to the evaporator 120 in a pipe shape.

[0064] The evaporator 120 is located in the low-temperature region 230 inside the drying chamber 200.

[0065] The evaporator 120 can function to liquefy or sublimate the water vapor inside the drying chamber 200. Therefore, it may be applied in any form and at any position. However, according to a preferred embodiment of the present invention, it can be configured in a coiled shape wound round like the condenser 110.

[0066] The configurations of the condenser 110 and the evaporator 120 may be, for example, as shown in FIG. 1, where the condenser 110 is located at the lower part of the drying chamber 200 and the evaporator 120 is located at the upper part. The drying chamber 200 may be formed in the vertical direction. As shown in FIG. 2, the drying chamber 200 may be formed in the horizontal direction, the condenser 110 may be located on one side inside the drying chamber 200, and the evaporator 120 may be located on the other side and arranged side by side.

[0067] At this time, an expansion valve 140 may be provided at the connection part between the condenser 110 and the evaporator 120.

[0068] The expansion valve 140 functions to reduce the pressure of the high-temperature and high-pressure refrigerant compressed and condensed in the condenser 110 to the pressure that causes evaporation. Also, the expansion valve 140 can function to adjust the flow rate of the refrigerant and supply it to the evaporator 120.

[0069] After the high-temperature and high-pressure refrigerant in the condenser 110 is rapidly decompressed to a low pressure through the expansion valve 140 and then discharged to the evaporator 120 to form a low-temperature cooling state, the expansion valve 140 can be a reference point that divides the high-temperature region 220 by the condenser 110 and the low-temperature region 230 by the evaporator 120 inside the drying chamber 200.

[0070] One end of the evaporator 120 may be connected to the condenser 110, and the other end may be connected to the second heat exchanger 132.

[0071] The storage tank 124 is located inside the drying chamber 200. The upper end of the storage tank 124 is connected to a cyclone 121 (to be described later), and the condensed water that has undergone a phase transition to water or ice liquefied or sublimated by the evaporator 120 is transmitted and stored. The lower end is connected to a discharge pump 150 outside the drying chamber 200 and can function to discharge it to the outside.

[0072] A pipe is connected to the lower end of the storage tank 124, penetrates the lower part of the drying chamber 200, and is connected to the discharge pump 150 provided outside the drying chamber 200. The discharge pump 150 can function to discharge the condensed water from the storage tank 124.

[0073] At this time, in order to prevent the condensed water from flowing back from the discharge pump 150 to the storage tank 124, a check valve 151 may be provided adjacent to the discharge pump 150 in the outer section of the drying chamber 200 between the discharge pump 150 and the storage tank 124.

[0074] The compressor 130 may be formed in a structure where one end is connected to the first heat exchanger 131 and the other end is connected to the second heat exchanger 132. Eventually, the refrigerant compressed by the compressor 130 is transmitted to the condenser 110 through the first heat exchanger 131, and forms a circulation structure that is connected from the condenser 110, through the expansion valve 140, the evaporator 120, the second heat exchanger 132, and back to the compressor 130 again.

[0075] In summary, it circulates in the order of the compressor 130 → the first heat exchanger 131 → the condenser 110 → the evaporator 120 → the second heat exchanger 132 → the compressor 130.

[0076] From the above structure, it can be seen that no vacuum pump is configured, nor is a heater or a heat medium used. When the inside of the drying chamber is saturated with water vapor in this state and then the temperature is lowered, the water vapor rapidly decreases in volume while undergoing a phase transition to a liquid or a solid. As a result, the inside of the drying chamber becomes a vacuum state. Therefore, a low-temperature vacuum state can be formed with the above-described components without a vacuum pump, a heater, or a heat medium, and the drying quality of the object to be dried can be improved by performing rapid drying at a high temperature.

[0077] Looking at the detailed operation of the vacuum dryer 10 that does not require the vacuum pump of the present invention based on the above simple description, it is as follows.

[0078] First, the steam generator 300 uses the water stored in the water tank 310 to generate water vapor, and injects the water vapor into the inside of the drying chamber 200 through the steam injection port 210.

[0079] At this time, open the exhaust valve 211 at the upper end of the drying chamber 200 to discharge the air inside the chamber, so that the air inside the drying chamber 200 is replaced by water vapor.

[0080] When the inside of the drying chamber 200 is saturated with water vapor, close the exhaust valve 211 and the steam inlet 210 to seal the drying chamber 200.

[0081] Next, after setting the heat exchange capacity of the first heat exchanger 131 to the maximum value, drive the heat pump 100.

[0082] The heat pump 100 releases heat to the outside of the drying chamber 200 through the first heat exchanger 131. At the same time, due to the external dissipation of heat, the compressed refrigerant is supplied to the condenser 110, so that the drying chamber 200 saturated with water vapor begins to cool.

[0083] As the drying chamber 200 cools, in the low-temperature region 230, the water vapor is phase-transitioned and condensed into water or ice by the evaporator 120, so the pressure inside the drying chamber 200 decreases.

[0084] Ultimately, an initial vacuum state can be formed inside the drying chamber 200 without a vacuum pump.

[0085] When the inside of the drying chamber 200 becomes a low-temperature vacuum state, reduce the heat exchange capacity of the first heat exchanger 131 and start supplying the heat dissipated to the outside to the condenser 110.

[0086] In this process, adjust the capacity of the first heat exchanger 131 to adjust the heat generation amount of the condenser 110, and adjust the capacity of the second heat exchanger 132 to adjust the heat absorption amount of the evaporator 120, so as to adjust the heat balance between the high-temperature region by the condenser 110 and the low-temperature region by the evaporator 120 in the drying chamber 200.

[0087] The heat supplied to the condenser 110 forms a high-temperature region 220 inside the drying chamber 200 and dries the object to be dried spread on the drying table 213 located above the condenser 110.

[0088] This state has a structure that dries only the area where the object to be dried is located at a high temperature while the inside of the drying chamber 200 is in a low-temperature vacuum state.

[0089] Therefore, in a vacuum state, the evaporation of moisture from the object to be dried occurs more easily, and rapid drying at a low temperature improves the quality of dried foods. When drying is performed in the above-mentioned low-temperature vacuum state, it becomes possible to have the highest drying quality, and it can be seen that this process is possible with a simple configuration without heat media such as a vacuum pump and a heater.

[0090] On the other hand, looking at the inside of the drying chamber 200 during drying, in the high-temperature region 220, heat is continuously supplied from the condenser 110 to the object to be dried, and drying is continuously performed. In the low-temperature region 230, water vapor is condensed (liquefied) or deposited (sublimated) in the evaporator 120 to change into water or ice, and the vacuum state inside the space is continuously maintained.

[0091] Also, although a thermally unbalanced state in which the low-temperature region 230 continues to be cooled and the high-temperature region 220 continues to be heated persists, the total entropy of the entire inside of the closed drying chamber 200 maintains a thermal equilibrium state that is kept almost constant, and a state in which drying continuously progresses is maintained.

[0092] As shown in FIG. 3, looking at the state curve of water, it can be seen that water boils at 100°C at 1 atm, but boils at about 70°C at 0.3 atm, about 60°C at 0.2 atm, and about 46°C at 0.1 atm. This is because the vapor pressure of water changes in proportion to the temperature.

[0093] Saying that water boils means the same as that very rapid drying is performed.

[0094] There are low-temperature and low-pressure dryers on the market that utilize this principle, but in order to maintain the low pressure inside the drying chamber 200, it is necessary to install a blower 123. Since it is a blower that operates under atmospheric pressure, the pressure difference at both ends of the blower 123 during driving becomes larger as the pressure inside the drying chamber 200 becomes lower.

[0095] Therefore, a general blower 123 cannot be used, and it can be seen that the actually used low-temperature and low-pressure dryer is equipped with a high-performance ring blower or turbo blower with a very large negative pressure.

[0096] The vacuum dryer 10 that does not require a vacuum pump according to an embodiment of the present invention can increase the internal pressure and temperature of the dryer when increasing the heat supply into the drying chamber 200 through the first heat exchanger 131, and can decrease the internal pressure and temperature of the dryer when reducing the heat supply.

[0097] This is also applied in the low-temperature region 230.

[0098] Therefore, it is possible to freely set and operate the operation mode from the low-temperature and low-pressure drying region (Region B in FIG. 3) to the vacuum freeze-drying region (Region A in FIG. 3) without the need for a high-performance blower 123 or a vacuum pump, and it is possible to flexibly change the operation mode as needed even during the operation of the dryer.

[0099] Elements closely related to drying include temperature, humidity, and blowing.

[0100] As shown in FIG. 3, it can be said that the effect of blowing is slight in the vacuum freeze-drying region, but when the pressure becomes high at a low pressure, blowing becomes an element that cannot be ignored and affects drying.

[0101] That is, in the low-temperature and low-pressure drying region, blowing begins to emerge as a significant element.

[0102] To compensate for this, the vacuum dryer 10 that does not require a vacuum pump according to an embodiment of the present invention is improved by installing a blower 123 and a cyclone 121 in the evaporator 120 in the low-temperature region 230 where water vapor condensation or freezing occurs, so as to increase the drying speed.

[0103] The cyclone 121 may be conical and configured in a form surrounded by the coiled evaporator 120. In one embodiment of the present invention, the wide cylindrical portion at one end may be directed upward, and the narrow conical portion at the other end may be directed downward.

[0104] At one end of the cyclone 121, a pipe may protrude horizontally in a chimney shape from the side surface of the cylindrical portion toward the high-temperature region 220 to form a suction port 121a.

[0105] The water vapor that has passed through the high-temperature region 220 through the suction port 121a flows into the cyclone 121, and the cooling action is continuously performed by the evaporator 120 surrounding the cyclone 121. As a result, the water vapor that has flowed into the cyclone 121 undergoes a phase transition to water or ice by condensation or coagulation and is collected in the storage tank 124.

[0106] A blower 123 may be provided at the cylindrical portion at one end of the cyclone 121 to cover the upper end of the cyclone 121 corresponding to the shape of the cylindrical portion, and a discharge port 123a may be provided on the side surface of the blower 123.

[0107] Also, a motor 122 may be mounted on the upper end of the blower 123, and the operation of the motor 122 can discharge the water vapor in the blower 123 to the outside through the discharge port 123a.

[0108] In summary, in one embodiment of the present invention, the evaporator 120 in the low-temperature region 230 is provided with a cyclone 121 in the inner space formed in a coil shape, the blower 123 and the motor 122 are continuously in contact with each other above the cyclone 121, and a storage tank 124 is connected below the cyclone 121 to form a configuration.

[0109] The water vapor in the drying chamber 200 flows into the suction port 121a of the cyclone 121 and is cooled by the evaporator 120 surrounding the cyclone 121, condensed or solidified, and collected in the storage tank 124 as water or ice. At this time, a small amount of water vapor that is not condensed is discharged through the discharge port 123a of the blower 123 by the air flow generated by the motor 122.

[0110] That is, when the water vapor flowing into the cyclone 121 undergoes a phase transition to water or ice, it descends into the storage tank 124, and the water vapor remaining in the vapor state without undergoing a phase transition will go through the process of being discharged back into the drying chamber 200 again.

[0111] Since the operating environment of the blower 123 is in a very low pressure region below atmospheric pressure, a general blower 123 with appropriately designed blade shapes can be used.

[0112] The suction port 121a of the cyclone 121 can be geometrically formed and appropriately arranged so as to effectively collect the water vapor generated in the high temperature region 220 as shown in FIG. 2.

[0113] According to the kinetic theory of gases, the pressure of a gas is defined as the force with which molecules collide with the walls of the container. Even in the vacuum freeze-drying region where sublimation occurs at a pressure of 0.006 atmospheres, the number of water vapor molecules per liter is an astronomical number, so it can be seen that the effect of the air flow is significant.

[0114] The ice condensed in the cyclone 121 can be collected in the storage tank 124 by using a defrost heater or by the defrost operation of the heat pump 100.

[0115] The condensed water in the form of water or ice collected in the storage tank 124 through the cyclone 121 can be discharged by the operation of the discharge pump 150 connected to the cyclone 121 and provided outside the drying chamber 200, and can be recovered in the water tank 310 through a pipe.

[0116] The discharge pump 150 can function to extract condensed water from the storage tank 124 using suction force and send it to the water tank 310.

[0117] At this time, a check valve 151 is provided at the connection part between the discharge pump 150 and the storage tank 124, which can prevent the condensed water from flowing back into the storage tank 124.

[0118] The condensed water recovered in the water tank 310 is regenerated into water vapor by the steam generator 300, saturates the inside of the drying chamber 200, and then circulates through the process of being cooled and condensed and discharged.

[0119] In this way, it is possible to ensure the maximization of the recycling efficiency of resources through the process of reusing water resources without waste.

[0120] On the other hand, the refrigerant that has been depressurized from the condenser 110 through the expansion valve 140 and then transmitted to the evaporator 120 is transmitted along the pipeline outside the drying chamber 200 through the evaporator 120 while maintaining the low-temperature and low-pressure state inside the drying chamber 200, and is transmitted to the second heat exchanger 132.

[0121] The second heat exchanger 132 can function to convert the incoming high-pressure refrigerant into a low-pressure refrigerant through a heat exchange action and then prepare it to be compressed again into a high-pressure refrigerant by the compressor 130 through the first heat exchanger 131.

[0122] As a result, the heat of the heat pump 100 generated by the compressor 130 being compressed to high temperature and high pressure in the first heat exchanger 131 is circulated to the second heat exchanger 132 through the process of heat generation (drying) in the high-temperature region 220 and heat absorption (condensation) in the low-temperature region 230 inside the drying chamber 200. Therefore, no energy loss other than drying occurs and the energy efficiency becomes very high.

[0123] That is, since all heat transfer involved in drying is carried out inside the drying chamber 200 without loss to the outside, very high-efficiency energy saving is possible.

[0124] And, in the heat transfer process and the drying process, since no vacuum pump is configured and no heat generating medium such as a heater is provided, it not only has a simple configuration but also can have the advantage of being able to produce high-quality dried products.

[0125] Based on the above description, looking at the usage example according to a preferred embodiment of the vacuum dryer 10 that does not require a vacuum pump of the present invention, it is as follows.

[0126] First, the user opens the lid of the drying chamber 200 and places the object to be dried on the drying table 213 in the drying chamber 200.

[0127] Next, close the lid of the drying chamber 200 and set the heat exchange capacity of the first heat exchanger 131 to the maximum value.

[0128] Then, open the steam inlet 210 and the exhaust valve 211. After connecting the steam generator 300 to the steam inlet 210, operate the steam generator 300 to inject steam into the drying chamber 200.

[0129] At the same time as steam is injected into the drying chamber 200, the air inside the drying chamber 200 is discharged to the outside of the drying chamber 200 through the exhaust valve 211.

[0130] Throughout this process, replace the inside of the drying chamber 200 with steam instead of air. When the steam saturates the drying chamber 200, close the exhaust valve 211 and the steam inlet 210.

[0131] Then, drive the heat pump 100.

[0132] Since the heat pump 100 operates while releasing heat to the outside of the drying chamber 200 via the first heat exchanger 131, the condensation process is performed in the condenser 110 inside the drying chamber 200, the pressure is reduced through the expansion valve 140, and in the low-temperature region 230 where the heat generator is located, water vapor is phase-transitioned to water or ice and condensed. As a result, the pressure inside the drying chamber 200 decreases, and the inside of the drying chamber 200 becomes a vacuum state even without a vacuum pump.

[0133] When the operating mode of the desired pressure and temperature is reached by the user, the heat exchange capacity of the first heat exchanger 131 is reduced, and heat supply to the condenser 110 of the heat pump 100 is started.

[0134] At this time, by adjusting the capacity of the first heat exchanger 131, the heat generation amount of the condenser 110 and the heat absorption amount of the evaporator 120 are adjusted so that thermal equilibrium can be achieved inside the drying chamber 200.

[0135] As a result, drying of the object to be dried is performed on the drying table 213 located in the high-temperature region 220 where the condenser 110 generates heat. In this state, since the inside of the drying chamber 200 is in a vacuum state as a whole and the evaporator 120 maintains a low temperature through the liquefaction or sublimation process in the low-temperature region 230, drying of the object to be dried can be rapidly performed in a low-temperature vacuum state.

[0136] Therefore, the object to be dried in the best state can be obtained.

[0137] When the drying is completed, the operation of the heat pump 100 is stopped, the exhaust valve 211 is opened, and then the lid can be opened to take out the object to be dried.

[0138] Through the above procedure, the drying process of the object to be dried can be advanced using the vacuum dryer 10 that does not require a vacuum pump of the present invention.

[0139] Summarizing the above process and summarizing the features of the present invention, it is as follows.

[0140] One mole of water weighs 18 grams. When it evaporates under standard conditions and turns into water vapor, it becomes 22.4 liters at 1 atmosphere. Therefore, in the case of water, when in the liquid or solid state, a volume change of about 1,200 times occurs compared to the gaseous state.

[0141] That is, if a 22.4-liter sealed space is filled with water vapor at 1 atmosphere and heat is removed from the inside to condense the water vapor, the water vapor undergoes a state change to 18 cc of water. As a result, the pressure in the sealed space drops to about 1 / 1,200 (below 0.001 atmosphere).

[0142] Since drying is an operation to remove the moisture contained in a substance, a new vacuum dryer can be constructed by utilizing such physical properties of water.

[0143] That is, after filling the inside of the sealed drying chamber 200 with water vapor and then driving the heat pump 100 inside the drying chamber 200, the water vapor is condensed in the evaporator 120 area, causing the pressure inside the drying chamber 200 to drop. The heat recovered by the evaporator 120 is supplied to the object to be dried as drying heat in the condenser 110 area.

[0144] Looking at this process, it can be seen that by simply driving the heat pump 100 inside the drying chamber 200, there is no need to configure a vacuum pump, and the evaporation and condensation of moisture can be continuously carried out while maintaining a vacuum.

[0145] Also, by appropriately adjusting the evaporator 120 and the condenser 110, the pressure can be set and maintained from low-pressure drying to vacuum drying, and the temperature can be set and maintained from low-temperature drying to freeze-drying. Thus, it can be understood that an innovative dryer with various functions can be constructed.

[0146] The embodiments of the present invention described above are merely exemplary, and it will be well understood by those of ordinary skill in the technical field to which the present invention pertains that various modifications and equivalent other embodiments will be possible hereinafter.

[0147] Therefore, it can be understood that the present invention is not limited to the forms mentioned in the above detailed description. Thus, the true technical protection scope of the present invention should be defined by the technical idea of the appended claims.

[0148] In addition, the present invention should be understood to include the spirit of the present invention defined by the appended claims and all modifications, equivalents, and alternatives within the scope thereof.

Explanation of Reference Numerals

[0149] 10 Vacuum dryer that does not require a vacuum pump 100 Heat pump 110 Condenser 120 Evaporator 121 Cyclone 121a Suction port 122 Motor 123 Blower 123a Discharge port 124 Storage tank 130 Compressor 131 First heat exchanger 132 Second heat exchanger 140 Expansion valve 150 Discharge pump 151 Check valve 200 Drying chamber 210 Steam inlet 211 Exhaust valve 212 Exhaust check valve 213 Drying table 220 High-temperature region 230 Low-temperature region 300 Steam generator 310 Water tank 311 Drain

Claims

1. A drying chamber that forms a sealed internal space, is provided with a drying rack inside, has a steam inlet linked to an exhaust valve on one inner side, and an exhaust valve linked to the steam inlet on the outside of the other side, A steam generator that is located outside the drying chamber, has a water tank, and is connected to the steam inlet, A heat pump that is provided in conjunction with the inside and outside of the drying chamber and forms a high-temperature region and a low-temperature region inside the drying chamber, When the steam generator saturates the inside of the drying chamber with water vapor, the heat pump drops the temperature inside the drying chamber to liquefy or sublime the water vapor and reduce its volume, thereby forming a vacuum state inside the drying chamber, The heat pump further includes a condenser provided in the high-temperature region, a first heat exchanger connected to the condenser outside the drying chamber, an evaporator provided in the low-temperature region, a second heat exchanger connected to the evaporator outside the drying chamber, a compressor connecting the first heat exchanger and the second heat exchanger, and an expansion valve connecting the condenser and the evaporator, A conical cyclone configured in a shape surrounded by the evaporator, a blower inserted and mounted in the cylindrical portion at one end of the cyclone, and a motor mounted on the upper end of the blower, The cyclone has an internal space formed and connected from a tubular suction port provided in the cylindrical portion at one end to the conical portion at the other end. The blower is provided with a discharge port on the side, and the lower end is connected to the inside of the cyclone. The air blown generated by the motor is configured to communicate with the discharge port and the conical portion. A vacuum dryer that does not require a vacuum pump, characterized by further including the above.

2. Further including a storage tank connected to the conical portion of the cyclone, The storage tank is connected to a discharge pump outside the drying chamber. The discharge pump is connected to the water tank by a pipe. The water vapor generated in the high-temperature region of the drying chamber is condensed by the cyclone and discharged in the form of water or ice, and is recovered in the storage tank, further including forming a circulation structure, characterized by the vacuum dryer according to Claim 1 that does not require a vacuum pump.

3. Further including a check valve at the site where the storage tank and the discharge pump are connected outside the drying chamber to prevent the condensed water in the storage tank from flowing back into the storage tank, characterized by the vacuum dryer according to Claim 2 that does not require a vacuum pump.

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