KR100789215B1 - A vacuum freeze drying device using binary refrigeration and heat pump methods - Google Patents

Abstract

A vacuum freeze-drying device is provided to freeze dry a material to be dried in a process chamber at ultra-low temperature and save the energy required for sublimation of moisture. In a conventional freeze-drying device which uses sublimation in a high vacuum state, includes a process chamber(200) equipped with a heat plate and a condenser chamber(300) connected to the process chamber through a pipe and equipped with a cold trap(550), a freezing cycle of the device comprises a self-freezing circuit in which a first compressor(510), a first condenser(520), a first expansion valve(530), a heat plate(540) and the first compressor are connected, a circuit for increasing temperature of the heater plate and maintaining the temperature of the cold trap in which the first compressor, the heater plate, a second expansion valve(531), the cold trap and the first compressor are connected, and a circuit for cooling the cold trap and the maintaining the temperature in which the first compressor, the first condenser, the second expansion valve, the cold trap and the first compressor are connected, a by-pass valve(C2) is equipped with an outlet side of the first compressor to constantly maintain the refrigerant outlet pressure, and a check valve(710) is included in the freezing cycle to prevent the counter-current of the refrigerant between the conversion of the circuits.

Description

A vacuum freeze drying device using binary refrigeration and heat pump methods}

1 is a schematic view showing a circuit of a conventional freeze drying apparatus

2 is a perspective view showing a schematic configuration of a freeze-drying apparatus according to the present invention

Figure 3 is a perspective view showing a process chamber and the like of the freeze-drying apparatus according to the present invention

Figure 4 is a side view showing the first door side of the freeze drying apparatus according to the present invention

5 is a left and right side view of the freeze drying apparatus according to the present invention

6 is a cycle schematic diagram of the two-way refrigeration and heat pump type freeze drying apparatus according to the present invention

7 is a schematic diagram of the self-freezing mode cycle of the freeze drying apparatus according to the present invention

8 is a schematic view of the hot plate temperature rise and cold trap temperature holding mode cycle of the freeze drying apparatus according to the present invention

9 is a cold trap cooling and temperature holding mode cycle of the freeze drying apparatus according to the present invention

10 is a temperature graph for explaining a control algorithm according to the present invention

11 is a configuration diagram showing a second embodiment of the freeze drying apparatus according to the present invention

12 is a configuration diagram showing a third embodiment of the freeze drying apparatus according to the present invention

Figure 13 is a block diagram showing a fourth embodiment of the freeze drying apparatus according to the present invention

Figure 14a, b is a block diagram showing a fifth embodiment of the freeze-drying apparatus according to the present invention

<Explanation of symbols for the main parts of the drawings>

110: body 130: conduit

140: vacuum pump 150: control unit

200: process chamber 210: lathe

300: condenser chamber 400: low temperature cycle

410: second compressor 440: third evaporator

500: cryogenic cycle 510: first compressor

512: oil separator 511: liquid separator

521: second condenser 540: hot plate

550: cold trap 570: temperature sensor

580: solenoid valve 600: counter flow heat exchanger

The present invention can realize the ultra low temperature of the process chamber in a short time by using the two-way refrigeration and regeneration cycle, energy saving in the sublimation of minutes by adopting the heat pump temperature rise cycle of the heat pump method, defrost of the cold trap In addition, the present invention relates to a vacuum freeze drying apparatus in which a separate device is unnecessary by using a refrigerant gas having a high temperature and high pressure.

In general, many materials need to maintain 2% w / w or less of residual moisture upon drying for stable storage and transport. Freeze-drying is widely used as a method of drying foods, drugs, or cells in food processing, pharmaceutical, and biological fields. After freezing an object at a low temperature, the pressure in the process chamber in which the object is loaded is lower than the triple point of water. It is a drying method in which the frozen water is directly sublimated with water vapor and dried at a state lowered to about 6 millibars or less. Moisture in the dry object in the form of ice is not liquefied due to low water vapor partial pressure below the triple point as the hot plate in the process chamber is gradually heated, leaving a myriad of spaces in the material. The porous object dried by the lyophilization method can be completely and quickly rehydrated, and even if the material is sensitive to heat, damage can be minimized and deactivated.

Conventional freeze dryers for drying agricultural products and the like typically have a configuration as shown in FIG. The dry object 1 is placed on the shelf 12 in the chamber 11 and maintained airtight, and the compressor 22, the condenser 23, the expansion valve 26, and the evaporator and the refrigerant pipe joined to the bottom of the shelf 12 are provided. It is frozen by the refrigeration cycle consisting of (21). On the other hand, the chamber 11 is connected to the steam condensation chamber 42 having a cooling coil 43 by a conduit 41, the steam condensing chamber 42 is connected to the vacuum pump 52 again It is kept in vacuum during the sublimation work. The cooling coil 43 of the steam condensing chamber 42 is cooled by a partial cycle branched into a part of the refrigeration cycle and kept at a low temperature to collect sublimed water. If the sublimation of moisture in the state in which the chamber 11 is maintained at a low partial pressure is required to supply an appropriate energy, which is supplied by the circulation cycle 33 of brine using the electric heater 31. That is, the dry matter 1 accumulated on the shelf 12 is frozen at low temperature and sublimates by obtaining heat from the brine of the circulation cycle 33 flowing down the shelf 12. The sublimed water is transferred to the steam condensation chamber 42 through the conduit 41 and implanted in the cold cooling coil 43 of the steam condensation chamber 42. After the ice is completely dried, it is melted by batch water and discharged to the outside.

However, the conventional lyophilizer as shown in FIG. 1 has a disadvantage in that rapid freezing is impossible by using a single freezing cycle. In general, rapid freezing is allowed to pass through the freezing point temperature zone for about 30 minutes to produce fine ice crystals in the material, so that the cell structure of the dry matter is almost completely maintained. While keeping room temperatures down to -40 degrees Celsius, a single refrigeration cycle was in fact difficult given the realistic compressor capacity and manufacturing costs. In addition, the conventional lyophilizer uses a heater and brine circulation cycle or sprays hot water in the supply of energy required for sublimation of water and the defrost of the steam condensation chamber. There was also a disadvantage that the production cost is high.

The present invention is to solve the above problems, it is possible to cryogenic fast freezing of the dry matter in the process chamber, to save energy in the supply of energy required for the sublimation of moisture, defrost of cold trap is also low cost It is an object of the present invention to provide a vacuum freeze drying apparatus capable of energy.

In order to achieve the above technical problem, the present invention uses a sublimation in a high vacuum state, has a process chamber and a condenser chamber leading to the process chamber and a conduit, the process chamber is provided with a hot plate in the form of a shelf, and the condenser chamber is cold. In the conventional freeze-drying apparatus provided with a trap, the freezing cycle of the freeze-drying apparatus includes a self-freezing circuit leading to a first compressor, a first condenser, a first expansion valve, a hot plate, and a first compressor; A hot plate temperature rising and cold trap temperature holding circuit leading to the first compressor, the hot plate, the first condenser, the second expansion valve, the cold trap, and the first compressor; A first trap, a first condenser, a second expansion valve, a cold trap, and a cold trap cooling and temperature holding circuit leading to the first compressor, wherein the bypass valve of the first compressor maintains a constant refrigerant outlet pressure. Is provided, the refrigeration cycle provides a vacuum freeze-drying apparatus employing a heat pump method, characterized in that the check valve for preventing the reverse flow of the refrigerant between the switching of the circuit.

In addition, the freeze-drying apparatus further includes a temperature sensor and a control unit disposed on the hot plate, and the control unit controls the temperature of the hot plate by PID control by inputting the temperature of the temperature sensor, The temperature is controlled to cascade.

In addition, the upper side of the shelf is provided with a plurality of protrusions, and further includes a tray for storing the object to be spaced apart from the shelf by the protrusion.

In addition, a second condenser is further provided at a portion directly connected to the first condenser in each circuit of the freezing cycle of the freeze-drying apparatus; The second compressor, the third condenser, the third expansion valve, the third evaporator, and further comprises a low temperature cycle circuit continuously connected to the second compressor, the second condenser and the third evaporator is a counter flow heat exchanger mutually Heat exchange takes place.

In addition, a second evaporator is further provided immediately in front of the first compressor in each circuit of the freezing cycle of the freeze-drying apparatus, and the second evaporator and the first condenser constitute a regeneration cycle by mutual heat exchange.

In addition, the third condenser of the low temperature cycle circuit is installed in contact with each other to exchange heat with the second evaporator of each circuit of the refrigeration cycle.

In addition, the self-freezing circuit of the freeze-drying device of the freeze-drying device is specifically a first compressor, p1 pipe, p2 pipe, A1 solenoid valve, p3 pipe, p4 pipe, the first condenser, p5 pipe, the second condenser, p6 pipe, The A2 solenoid valve, the first expansion valve, the hot plate, the p8 piping, the A3 solenoid valve, the p9 piping, the p10 piping, the second evaporator, the p11 piping, and the first compressor are continuously connected.

In addition, the hot plate temperature rise and cold trap temperature holding circuit of the freeze-drying device of the freeze-drying apparatus is specifically, the first compressor, p1 pipe, p2 pipe, B1 solenoid valve, p12 pipe, hot plate, p8 pipe, B3 solenoid valve, p13 pipe , p4 piping, first condenser, p5 piping, second condenser, p6 piping, B2 solenoid valve, second expansion valve, p14 piping, cold trap, p15 piping, p10 piping, second evaporator, p11 piping, back to the first compressor It has a configuration that continues in succession.

In addition to the above, the cold trap cooling and temperature holding circuit of the freeze drying device of the freeze-drying apparatus is specifically a first compressor, p1 piping, p2 piping, A1 solenoid valve, p3 piping, p4 piping, the first condenser, p5 piping, The second condenser, the p6 pipe, the B2 solenoid valve, the second expansion valve, the p14 pipe, the cold trap, the p15 pipe, the p10 pipe, the second evaporator, the p11 pipe, and the condenser are continuously connected to the first compressor.

As another aspect of the present invention, the refrigeration cycle of the lyophilization device is further provided with a cold trap defrost cycle, the defrost cycle is the first compressor, C1 valve, p24 pipe, p14 pipe, cold trap 550, p15 Provided is a vacuum lyophilization apparatus employing a heat pump method characterized in that the pipe, p10 pipe, the second evaporator 560, p11 pipe, the first compressor continuously connected to.

2 is a perspective view showing a schematic configuration of a freeze drying apparatus according to the present invention, Figure 3 is a perspective view showing a processor chamber and the like of the freeze drying apparatus according to the present invention, Figure 4 is a first view of the freeze drying apparatus according to the present invention It is a side view which shows the door side, and FIG. 5 is a left and right side view of the lyophilization apparatus which concerns on this invention. In addition, Figure 6 is a schematic diagram of a two-way refrigeration and heat pump type freeze drying apparatus according to the present invention. In the drawings, parts that are not essential are not shown in order to clarify the understanding of the technical gist of the present invention, and the omitted parts are according to a conventional freeze-drying apparatus.

Hereinafter, the present invention will be described in detail with reference to Examples.

(First embodiment)

The first embodiment of the freeze drying apparatus according to the present invention will be described with reference to FIGS. 2, 5 and 6 as follows. In the freeze-drying apparatus 100 of the present invention, a condenser chamber 300 for collecting sublimed water and a processor chamber 200 in which a dry matter is placed in the cylindrical body 110 are disposed adjacent to the partition wall 120. The conduit 130 is configured to communicate with each other. The first door 220 is formed at one side of the process chamber 200 to allow the carrying of the dry goods, and the first observation window 230 is provided at the center of the first door 220 to perform a drying process. It can be monitored. The second door 320 and the second observation window 330 are also provided at one side of the condenser chamber 300, respectively. Each door is firmly in close contact with the body 110 to maintain high vacuum due to the operation of the vacuum pump 140. The process chamber 200 includes a shelf 210 for depositing a dry object, which simultaneously acts as a hot plate 540 of the cryogenic cycle 500 which will be described later. Shelf 210 is typically provided with a plurality of so as to enable the stacking of the dry matter. At the front and rear ends of the shelf 210 as the hot plate 540, refrigerant pipe connection parts 250a and b are respectively provided to connect the refrigerant pipe of the cryogenic cycle 500 to each other. The lower side of the process chamber 200 is further provided with a first drain pipe 240 serves to drain water generated in the process chamber 200 by the cleaning or malfunction of the chamber. The first drain pipe 240 is also provided to enable a high degree of sealing to maintain a high vacuum in the chamber. A part of the shelf 210 is attached to a temperature sensor 570 as a monitoring means for temperature control of the shelf 210 and the temperature of the shelf 210 measured by the temperature sensor 570 is a controller 150 (not shown). Is delivered.

The condenser chamber 300 collects water vapor generated while sublimation of ice in the form of ice, which is frozen inside the object in the process chamber. This sublimated water vapor may be discharged to the outside by the vacuum pump 140 installed to form a vacuum in the condenser chamber 300, but since 1 ml of ice is at least 1,000,000 ml of steam at a pressure of a general freeze-drying process. Discharging to the vacuum pump 140 is uneconomical. In addition, since the exhausted water may cause the vacuum pump 140 to age, most of the steam is re-frozen by using the cold trap 550 of the cryogenic cycle 500 located in the condenser chamber 300, and after the drying is completed, defrosting. To discharge to the outside. The cold trap 550 of the cryogenic cycle 500 is disposed in the center of the condenser chamber 300. At both front and rear ends of the cold trap 550, coolant pipe connection parts 350a and b are connected to the refrigerant pipe of the cryogenic cycle. The lower portion of the condenser chamber 300 serves as a storage portion of water generated when ice cubes implanted on the cold trap 550 are defrosted, and the defrosted water is provided in the second drain pipe 340 provided in the lower portion of the condenser chamber 300. Is drained to outside. The second drain pipe 340 may also be closely closed, so there is no effect on the high vacuum in the chamber by the vacuum pump 140. On the other hand, the upper side of the condenser chamber 300 includes an exhaust line connecting portion 360 of the exhaust line 141 connected to the vacuum pump 140. The capacity of the vacuum pump 140 is set so that the target pressure of the process chamber 200 and the condenser chamber 300 can be achieved within about 20 minutes. The cold trap 550 may be additionally provided with a temperature sensor as needed, and the measured temperature value may be transmitted to the controller 150 to be used for monitoring and controlling the entire drying process. As is clear from the above description, the process chamber 200 and the condenser chamber 300 are connected in free communication with the conduit 130 so that the water sublimated in the dry matter in the process chamber 200 is free of the condensation chamber 300. It is implanted in the trap 550. Conduit 130 is usually provided in the form of a tube, but the shape is not limited, such as can be changed to a structural change, that is, the fallopian tube shape, etc. to keep the idea constant. In addition, a heater is additionally provided around the conduit 130 to prevent clogging of the conduit 130 due to the implanted moisture.

Next, the refrigeration cycle of the binary freezing and heat pump type vacuum freeze drying apparatus according to the present invention will be described using FIGS. 6 and 7 to 9. Parts not described below are well known in the art and may be omitted by those skilled in the art because they may be applied in combination without great difficulty within the scope of not impairing the technical gist of the present invention.

The refrigeration cycle of the present invention introduces a two-way refrigeration and heat pump method in a conventional freezing cycle for freezing. Binary refrigeration is a type of refrigeration that is employed to maintain the temperature in the target chamber at about -50 ° C., which has been mainly used for commercial or chemical purposes. In general, when a single compressor is used, the temperature of the evaporation side is determined according to the compressor capacity, the type of refrigerant, and the temperature of the condensation side, but the capacity of the compressor which is economically meaningful is limited, and the selection of the refrigerant that can be employed is limited. In general, since the temperature of the condenser is at room temperature, the target temperature that can be lowered to the maximum is also limited. One way to solve this problem is to introduce a dual refrigeration cycle that operates the refrigeration process step by step, ie, combines two or more refrigeration cycles operating in succession. The binary refrigeration cycle is combined with the condensation part of the low temperature side cycle (hereinafter referred to as "ultra low temperature cycle 500") and the evaporation part of the high temperature side cycle (hereinafter referred to as "low temperature cycle 400") to exchange heat with each other. Evaporator temperature of 500 is to allow the temperature to go down to very low temperatures. Binary refrigeration cycles reduce the work of the compressor, while increasing the refrigeration capacity, resulting in an improvement in the coefficient of performance. In the present invention, the cryogenic cycle 400 is used as a low temperature refrigerant, and the cryogenic cycle 500 uses an ultra low temperature refrigerant (boiling point -82 degrees) having excellent cryogenic characteristics, that is, the evaporation part of the cryogenic cycle 500, that is, the process chamber 200. ) It is designed to cool down the temperature to about -50 degrees.

6, the low temperature cycle 400 includes a second compressor 410, a p17 pipe, a third condenser 420, a p18 pipe, a third expansion valve 430, a third evaporator 440, and the like. p19 pipes are connected in sequence. An oil separator, a liquid separator, a control valve, etc. may be disposed in the path of each pipe of the low temperature cycle 400 as necessary. The third condenser 420 is in a room temperature state to exchange heat with the outside air by a fan, and the third evaporator 440 is a state in which the second condenser 521 and the refrigerant of the cryogenic cycle 500 are not mixed with each other. Combination is arranged in the form of counterflow heat exchanger 600 so that heat exchange occurs in the. The heat exchange capacity of the third condenser 420, the design of the heat exchange area of the counterflow heat exchanger 600, or the operation control method of the low temperature cycle 400 can be determined without particular difficulty using well-known techniques well known in the art. Can be done. Insulation of the counter-current heat exchanger 600 must be firmly maintained so that all heat transferred to the third evaporator 440 of the low temperature cycle 400 is transferred from the second condenser 521 of the cryogenic cycle 500. The low temperature cycle 400 of the two-way refrigeration system is operated at all times during the operation of each of the ultra-low temperature cycle 500 mode to realize the sex energy.

Next, the ultra low temperature cycle 500 will be described. The cryogenic cycle 500 includes a self-freezing mode 501, a hot plate temperature rise and cold trap temperature holding mode 502, and a cold trap cooling and temperature holding mode 503. First, the self-freezing mode 501 will be described with reference to FIG. The self-freezing mode 501 is a cycle in which the article is lowered to a target temperature after the article is loaded in the process chamber 200. In the self-freezing mode 501, the coolant is not circulated in the cold trap 550, and the hot plate 540 in the process chamber 200 serves as an evaporator, and the surface temperature of the shelf 210 is at least -50 degrees or less. Freeze rapidly to dry. The cycle configuration of the self-freezing mode 501 is the first compressor 510, p1 piping, oil separator 512, p2 piping, A1 solenoid valve, p3 piping, p4 piping, the first condenser 520, p5 piping, 2 condenser 521, p6 pipe, A2 solenoid valve, first expansion valve 530, hot plate 540, p8 pipe, A3 solenoid valve, p9 pipe, p10 pipe, second evaporator 560, p11 pipe continuously This is the configuration that follows. As shown in FIG. 7, at this time, the B1 solenoid valve leading from the p2 pipe and the B3 solenoid valve leading from the p8 pipe and the B2 solenoid valve leading from the p6 pipe should be closed. It is controlled by a control program mounted on the central processing unit. The oil separator 512 is provided in the discharge stage of the first compressor 510 and serves to filter the compressor oil discharged by the discharge pressure and return it through the p16 pipe. At the inlet end of the first compressor 510, a liquid separator 511 is attached to the p11 pipe and prevents liquid refrigerant from flowing into the first compressor 510. The low-temperature low-pressure saturated steam refrigerant is isotropically compressed into an ideal refrigerant of high temperature and high pressure by the first compressor 510, passes through the first condenser 520 and the second condenser 521, and is in a high temperature and high pressure saturated liquid state. It becomes The refrigerant in the saturated state passes through the first expansion side 530 and is throttled so that the pressure drops to the evaporator pressure. The refrigerant entering the hot plate 540 in a low dry saturated mixture is then evaporated by absorbing heat in the process chamber 200. At this time, the evaporation temperature of the refrigerant is set to be lower than the target temperature of the space to be refrigerated at about -40 ° C to -70 ° C, depending on the type of the dry matter. However, the cold trap temperature is set below -70 ° C. Some of the saturated liquid refrigerant not completely evaporated passes through the second evaporator 560 and is completely evaporated to return to the first compressor 510 in the saturated vapor state to complete the cycle by the self-freezing mode 501. As described above, since the second condenser 521 exchanges heat with the third evaporator 440 of the low temperature cycle 400 in the form of the counterflow heat exchanger 600 by the two-way refrigeration mode, condensation of the self-freezing mode 501 is performed. The temperature is sufficiently lower than normal outdoor temperature conditions, whereby the temperature of the evaporation unit of the ultra low temperature cycle, that is, the surface temperature of the hot plate 540 can be maintained at an extremely low temperature.

The regeneration cycle of the cryogenic cycle 500 will be described. As shown in FIG. 7, the first condenser 520 and the second evaporator 560 of the self-freezing mode 501 are disposed adjacent to each other to allow mutual heat exchange. Although the drawings are shown as stacked up and down, any structure can be used as long as the structure allows mutual heat exchange such as a counterflow method. By allowing heat exchange between the first condenser 520 and the second evaporator 560, the waste heat that should be discarded by the first condenser 520 is regenerated by the second evaporator 560. By the regeneration cycle, the high-pressure gas phase refrigerant is cooled more and the temperature flowing into the first expansion edge 530 is lowered. As a result, the outlet temperature of the first expansion edge 530 is also lowered, so that the temperature of the hot plate 540 is lowered. do. As a result, there is an advantage that the cryogenic realization in the process chamber 200 can be realized as compared to the conventional refrigeration cycle. The above matters regarding the regeneration cycle are also applied to the hot plate temperature rise and cold trap temperature holding mode 502 and the cold trap cooling and temperature holding mode 503 described below.

Next, the hot plate temperature rise and cold trap temperature holding mode 502 will be described with reference to FIG. 8. When it is confirmed by the self-freezing mode 501 that the dry matter in the process chamber 200 is lowered to the target temperature and completely frozen, the process chamber 200 is maintained in a high vacuum state and then drying is performed by sublimation. When heat energy is added to the hot plate 540 at a pressure below the triple point of water, the transferred heat is used as a latent heat of change in the state of moisture in the building and the sublimation action of the ice is immediately converted into water vapor. The evaporated water is collected by the cold trap 550 provided in the condenser chamber 300. Therefore, while the heat is supplied to the hot plate 540, the surface temperature of the cold trap 550 should be kept at an extremely low temperature. The heat pump temperature rise and cold trap temperature maintenance mode 502 of the heat pump method capable of the above operation is disclosed. The hot plate temperature rise and cold trap temperature maintenance mode 502 of the present invention, as shown in Figure 8, the first compressor 510, p1 piping, oil separator 512, p2 piping, B1 solenoid valve, p12 piping, Hot plate 540, p8 piping, B3 solenoid valve, p13 piping, p4 piping, first condenser 520, p5 piping, second condenser 521, p6 piping, B2 solenoid valve, second expansion valve 531, p14 The pipe, the cold trap 550, p15 pipe, p10 pipe, the second evaporator 560, p11 pipe, the first compressor 510 has a configuration that continues in succession. At this time, the A1 solenoid valve, the A3 solenoid valve, and the A2 solenoid valve must be kept closed. It is sufficient to toggle the opening and closing of the respective solenoid valves A1, A2, A3, B1, B2, and B3 in order to switch from the self-freezing mode 501 to the hot plate temperature rise and cold trap temperature holding mode 502. As can be seen by comparing FIG. 7 and FIG. 8, the hot plate 540 acts as an evaporation part of the cryogenic cycle 500, and acts as a condensation part into which a high-temperature, high-pressure steam refrigerant is introduced by mode conversion. Supply the latent heat necessary for sublimation. On the other hand, in the hot plate temperature rise and cold trap temperature maintenance mode 502, the cold trap 550 acts as an evaporation unit and the surface temperature is lowered to collect moisture introduced by the sublimation in the process chamber 200 by implantation. Will be. The effects of binary cooling by the low temperature cycle 400 or by the interaction of the first condenser 520 and the second evaporator 560 are the same in the hot plate temperature rise and the cold trap temperature maintenance mode 502.

The advantages of the heat pump method in sublimation of the vacuum freeze dryer will be described. As described above, in the related art, a brine circulation cycle 33 using a boiler or an electric heater 31 is used to supply energy required for sublimation. However, according to exergy theory, the electric heater 31 needs at least as much energy as the sublimation energy in order to supply the same amount of sublimation energy to the building, but the performance of the heat pump when the heat pump method is used. Assuming a coefficient of 3, it is known that about 1/3 of the energy is sufficient. This is beyond the conventional electric heater 31 which converts electrical energy introduced from the outside into thermal energy and delivers it to the object to be dried, by turning the first compressor 510 with less energy to process heat in the condenser chamber 300. This is what happens by moving to 200. Therefore, the sublimation process by the heat pump method of the present invention can not only be excellent in the supply efficiency of energy but also maintain the cold trap 550 at a very low temperature at the same time can be said to be excellent in energy efficiency.

Next, the cold trap cooling and temperature holding mode 503 will be described with reference to FIG. 9. When the temperature of the hot plate 540 continuously rises, the sublimation of the dry item is not made smoothly, and thus, the structure of the dry item is destroyed, thereby causing a drying accident. Thus, the hot plate temperature rise and the cold trap temperature maintaining mode 502 are performed. Cannot be operated continuously. That is, it is necessary to continuously regulate the thermal energy given to the hot plate 540. Of course, the temperature of the cold trap 550 at this time should be kept low to collect the moisture. In order to achieve this specific purpose, a cold trap cooling and temperature holding mode 503 is proposed. Cold trap cooling and temperature holding mode 503 is, as shown in Figure 6, the first compressor 510, p1 piping, oil separator 512, p2 piping, A1 solenoid valve, p3 piping, p4 piping, the first condenser 520, p5 piping, second condenser 521, p6 piping, B2 solenoid valve, second expansion valve 531, p14 piping, cold trap 550, p15 piping, p10 piping, second evaporator 560, The p11 pipe is configured to continuously connect to the first compressor 510. At this time, B1 solenoid valve, B3 solenoid valve, A2 solenoid valve, A3 solenoid valve should be kept closed. Pipes corresponding to other operation modes are shared in common, and the hot plate temperature rise and cold trap temperature maintenance mode 502 and the cold trap cooling and temperature maintenance mode 503 are switched by the controller 150 as necessary. . Switching of both modes is made possible simply by alternately toggling the A1 solenoid valve and the B1 solenoid valve, and controlling the B3 solenoid valve accordingly. As can be clearly seen in FIG. 9, in the cold trap cooling and temperature holding mode 503, the cold trap 550 is kept at a low temperature to continuously capture moisture, while the heat plate 540 has no energy transfer, so that sublimation is partially. There is a delayed effect. The effects of two-way refrigeration by the low temperature cycle 400 or by the interaction of the first condenser 520 and the second evaporator 560 are the same in the cold trap cooling and temperature holding mode 503.

Next, with reference to Figure 10 will be described the operation and control of the vacuum freeze drying apparatus employing a binary refrigeration and heat pump method according to the present invention. First, the user opens the first door 220 of the process chamber 200 to deposit the dry matter on the shelf 210. When the stacking is completed, the first door 220 and the second door 320 of the condenser chamber 300 are closed, and the valves such as the first drain pipe 240 and the second drain pipe 340 provided in each chamber are locked tightly. Keep it. Next, press the switch provided on the control panel to perform self-freezing. The object to be dried is rapidly frozen by the self-freezing mode 501 performed by the control of the controller 150. The freezing temperature of the dry matter to be finally frozen falls to approximately -40 degrees when the temperature of the hot plate 540 is maintained at about -50 degrees. A circulation fan, which is conventionally employed, may be employed to help fast freeze the object. Appropriate control is possible using the temperature sensor 570 provided on the hot plate 540, and the temperature difference between the object to be dried and the hot plate 540 should be maintained within -10 degrees to enable desirable heat transfer. When the self-freezing is determined to be complete, the cold trap is cooled to cryogenic temperature and vacuum evacuation is started after the cooling is completed. The controller 150 operates the vacuum pump 140 to vacuum the inside of the chamber at a pressure below the triple point of water. At this time, the pressure is appropriately about 0.01 Torr ~ 0.1 Torr. When the vacuum is completed, the vacuum state is maintained in the open state in the exhaust line 141. If necessary, the exhaust line 141 may further include a solenoid valve and a pressure gauge electronically controlled by the controller 150, and maintain high vacuum using PID control. In the high vacuum state, the controller 150 proceeds with the hot plate temperature rise and the cold trap temperature maintenance mode 502. Heat energy is transferred to the hot plate 540 acting as a condensation unit and used for sublimation of ice condensed on the dry matter, and the sublimed water is implanted in the cold cold trap 550 acting as the evaporation unit. A preferred temperature control embodiment of the hot plate 540 is shown in FIG. 10. The hot plate temperature rise and cold trap temperature maintenance mode 502 may vary depending on the amount of the dry goods, but may be continued for approximately one hour until the temperature of the hot plate 540 becomes -30 degrees. After that, the temperature is maintained for about 1 hour. The constant temperature maintenance process is possible by switching between hot plate temperature rise and cold trap temperature maintenance mode 502 and cold trap cooling and temperature maintenance mode 503 by PID control. That is, as described above, it is a step of controlling the supply of thermal energy to the hot plate 540 by simply toggling the solenoid valve. PID control is performed by using the temperature of the hot plate as an input using the temperature sensor 570 provided in the hot plate 540. By the constant temperature holding process, the dry matter partially having a temperature gradient is equilibrated to a constant temperature. Accordingly, the sublimation process is smooth without any imbalance, and drying accidents are prevented. Next, the hot plate temperature rise and cold trap temperature maintenance mode 502 proceeds for about 2 hours so that the temperature of the hot plate 540 reaches -10 degrees, and the hot plate temperature rise and cold trap temperature maintenance mode 502 and cold are performed. The process of maintaining a constant temperature by switching the trap cooling and temperature holding mode 503 is followed. As described above, the stepped PID temperature control is performed by the controller 150. After about 72 hours, the building reaches 60 degrees, and the remaining water in the building reaches about 4-6% w / w. Drying is complete. FIG. 10 shows only one embodiment of temperature control, and the temperature control of the present invention is not limited to that shown in FIG. 10. As the drying is completed, the user opens the valve provided in the vacuum exhaust line 141 to release the vacuum state, and opens the first door 220 to remove the dry object. The ice that has been implanted in the cold trap 550 may be naturally melted and removed, and may be removed using a spraying and defrosting cycle as necessary. Also mechanical removal is preferred. Water melted naturally or by watering and defrosting cycles is discharged to the outside through the second drain pipe 340 provided in the lower portion of the condenser chamber 300.

Second Embodiment

A second embodiment of the freeze-drying apparatus according to the present invention will be described with reference to FIG. 11 as follows. The second embodiment is related to the removal of moisture that is implanted in the cold trap 550, and is similar to the first embodiment except for this. According to the second embodiment of the present invention, the water trapped on the cold trap 550 is removed using a high temperature and high pressure steam type refrigerant naturally occurring in the cryogenic cycle 500. As described above in the hot plate temperature rise and cold trap temperature maintenance mode 502, the heat trap method is used in the defrost of the cold trap 550, and thus the energy efficiency is higher than that of the conventional electric heater. The defrost cycle 504 of the second embodiment will be described with reference to FIG. In addition to the first embodiment in order to realize the defrost cycle 504, a p21 pipe is further provided between the p15 pipe and the contact site where the cold trap 550 is connected from the contact site where the p12 pipe and the hot plate 540 are connected. The p21 piping is provided with an A4 solenoid valve and a third expansion valve 532. In addition, between the contact point of the p14 pipe and the cold trap 550 and the p6 pipe is further provided with a C4 solenoid valve and a p22 pipe, the B4 solenoid valve is further provided in the existing p15 pipe. The defrost cycle 504 will be described in more detail. The refrigeration cycle includes a first compressor 510, a p1 pipe, an oil separator 512, a p2 pipe, an A1 solenoid valve, a p3 pipe, a p4 pipe, and a first condenser 520. , p5 piping, second condenser 521, p6 piping, C4 solenoid valve, p22 piping, cold trap 550, p15 piping, p21 piping, third expansion valve 532, A4 solenoid valve, hot plate 540, p8 The pipe, the A3 solenoid valve, the p9 pipe, the p10 pipe, the second evaporator 560, the p11 pipe, and the first compressor 510 are continuously connected. A1 solenoid valve, B3 solenoid valve, A2 solenoid valve, B2 solenoid valve, and B4 solenoid valve which are not mentioned in the defrost cycle 504 should be kept closed. Also in the defrost cycle 504, the effects of dual cooling by the low temperature cycle 400 or by the interaction of the first condenser 520 and the second evaporator 560 are the same. As can be clearly seen from FIG. 8, the cold trap 550 acts as a condenser and the hot plate 540 acts as a cooling part, is a heat pump cycle, and the heat energy of the process chamber 200 is controlled by the heat pump. 550) to give a defrosting effect. As a result, the energy efficiency is drastically increased as compared with the conventional defrosting of the electric heater system. Defrosted water is discharged to the outside through the second drain pipe 340 provided under the condenser chamber 300.

(Third Embodiment)

A third embodiment of the freeze drying apparatus according to the present invention will be described with reference to FIG. 12. The third embodiment is similar to the first embodiment except that the position of the third condenser 420 of the low temperature cycle 400, which is at room temperature and is intended to be exchanged with the outside air by the fan, is changed. In general, when a liquid refrigerant is introduced into the compressor of the refrigerant, breakage of the compressor designed to handle only the refrigerant in the gas phase becomes a problem. Therefore, in the art, it is solved by installing a liquid separator 511, but in the third embodiment of the present invention, the third condenser 420 of the low temperature cycle 400 is the second evaporator 560 of the cryogenic cycle 500. This is solved by installing adjacent to allow heat exchange with. That is, the liquid refrigerant passing through the second evaporator 560 may be introduced into the first compressor 510 in a completely vaporized state by heat transfer from the third condenser 420 of the low temperature cycle 400, whereby Prevention of overcooling and breakage of the compressor can be prevented. In addition, according to the third embodiment of the present invention, the effect of the regeneration cycle may be doubled. In other words, the waste heat that should be discarded by the third condenser 420 is regenerated by the second evaporator 560.

(Example 4)

A fourth embodiment of the freeze-drying apparatus according to the present invention will be described with reference to FIG. In the fourth embodiment, a check valve 710 is installed at the rear end of the B3 solenoid valve to prevent the backflow of the refrigerant, and is connected between the p2 pipe connected to the outlet side of the first compressor 510 and the p11 pipe connected to the inlet side. It is similar to the first embodiment except that the pressure control bypass valve C2 and the solenoid valve C3 are connected to the p30 pipe. As shown in FIG. 8, the B3 solenoid valve is operated by intermittent operation when the freeze-drying apparatus is switched to the hot plate temperature rise and the cold trap temperature maintenance mode 502, and the refrigerant flows back in the process of switching to the self-freezing mode 501. Problems may arise. Since the switching between the two modes occurs frequently in accordance with the temperature change in the drying process, if the backflow of the refrigerant occurs, there is a problem that the drying performance can be sharply reduced. Therefore, in the fourth embodiment of the present invention, the check valve 710 is provided at the rear end of the B3 solenoid valve. The check valve 710 is known in the art to prevent a reverse flow in the direction of the B3 solenoid valve, while installed on the other side to the smooth flow.

In addition, in the fourth embodiment, a pressure regulating bypass valve C2 is provided between the outlet and the inlet of the first compressor 510. The bypass valve C2 prevents excessively high pressure of the refrigerant flowing into the B1 or A1 solenoid valve side. That is, when the outlet pressure of the first compressor 510 is higher than the set pressure value, the bypass operation is performed to maintain the pressure constant. The p30 pipe connecting the p2 pipe and the p11 pipe may further include an expansion tank 700 and a solenoid valve C3.

(Example 5)

The fifth embodiment of the freeze-drying apparatus according to the present invention will be described with reference to FIGS. 3 and 14A and b. The fifth embodiment is similar to the first embodiment except that the tray 211 is provided on the shelf 210 provided for the accumulation of the dried object in the cylindrical body 110 so as to be spaced apart from the shelf 210. . In the freeze-drying apparatus of the present invention, the self-freezing mode 501 and the hot plate 540 or the shelf 210 act as a condenser to operate the hot plate 540, that is, the shelf 210 as an evaporator, for smooth drying as described above. A switching operation is performed between the hot plate temperature rise and the cold trap temperature maintenance mode 502. When the shelf 210 acts as an evaporator and then as a condenser, the temperature of the surface of the shelf 210 is dramatically changed. That is, there is a sudden change between the evaporation temperature and the condensation temperature on the refrigerating cycle of the cryogenic cycle 500. In the hot plate temperature rise and the cold trap temperature holding mode 502, the refrigerant hot gas does not return by freezing. Failure to do so may occur. This is because the lyophilizer is switched to hot plate temperature rise and cold trap temperature holding mode 502 so that the shelf 210 is at the condensation temperature, while the dry matter stored on the shelf 210 is maintained at a temperature similar to the evaporation temperature. Because. That is, due to the low temperature of the dry matter, the refrigerant hot gas passing through the shelf 210 is frozen and the frozen refrigerant cannot be returned, thereby disturbing the entire cycle. In order to eliminate this problem, the fifth embodiment of the present invention includes a tray 211 formed to form a plurality of protrusions 212 on the upper surface of the shelf 210 and to be placed on the protrusions 212. As a result, the low-temperature dry matter is deposited on the tray 211 without being directly in contact with the shelf 210, so that the problem that the refrigerant hot gas is frozen does not occur. The dry items are stacked in a tray 211, frozen and evaporated by heat radiation.

By the vacuum freeze-drying apparatus employing the binary freezing method of the present invention as described above, it is possible to realize ultra low temperature in the process chamber, and energy saving by improving the coefficient of performance is possible.

In addition, the vacuum freeze-drying apparatus of the present invention has a merit that it is easy to realize ultra low temperature because the regeneration cycle is used as part of the ultra low temperature cycle. Rapid freezing of the dry objects by the realization of cryogenic is also possible.

In addition, the vacuum freeze-drying apparatus of the present invention has the advantage that the energy required by the shape of the coefficient of performance is possible because the supply of energy required for sublimation of water by using a two-way refrigeration and heat pump method.

In addition, the vacuum freeze-drying apparatus of the present invention has an advantage that the energy energy according to the shape of the performance coefficient is possible because the dual cooling and the heat pump method are used to supply the energy required for the defrost of the cold trap.

In addition, the vacuum freeze-drying apparatus of the present invention has the advantage of preventing damage to the compressor and heat regeneration by sufficiently heating the refrigerant entering the compressor of the cryogenic cycle using the heat of condensation of the low temperature cycle.

In addition, the vacuum lyophilization apparatus of the present invention can prevent the backflow of the refrigerant which may occur between mode switching, and prevent the excessive refrigerant pressure from occurring at the compressor outlet.

In addition, the vacuum lyophilization apparatus of the present invention has an effect of preventing hot gas freezing of the refrigerant that may occur between mode switching.

Claims (10)

A conventional lyophilization apparatus using a sublimation in a high vacuum state, having a process chamber and a condenser chamber leading to the process chamber and a conduit, wherein the process chamber is provided with a hot plate in the form of a shelf, and the condenser chamber is provided with a cold trap. The freezing cycle of the freeze-drying apparatus includes: a self-freezing circuit leading to a first compressor, a first condenser, a first expansion valve, a hot plate, and a first compressor; A hot plate temperature rise and cold trap temperature maintenance circuit leading to the first compressor, the hot plate, the first condenser, the second expansion edge, the cold trap, and again to the first compressor; A first trap, a first condenser, a second expansion valve, a cold trap, and a cold trap cooling and temperature holding circuit leading back to the first compressor, the bypass of the first compressor being bypassed to maintain a constant refrigerant outlet pressure. Valve is provided, the refrigeration cycle vacuum freeze-drying apparatus employing a heat pump method characterized in that the check valve for preventing the back flow of the refrigerant between the switching of the circuit The method of claim 1, The freeze-drying apparatus further includes a temperature sensor and a control unit disposed on the hot plate, and the control unit controls the temperature of the hot plate by PID control by inputting the temperature of the temperature sensor, but the temperature of the hot plate according to time in PID temperature control. Freeze-drying apparatus adopting the heat pump method characterized by controlling the stepping The method of claim 1, A plurality of protrusions are provided on the upper side of the shelf, and the vacuum freeze-drying apparatus employing the heat pump method is characterized in that it further comprises a tray for storing the workpieces spaced from the shelf by the protrusions. The method according to any one of claims 1 to 3, A second condenser is further provided at a portion directly connected to the first condenser of each circuit of the freezing cycle of the freeze-drying apparatus; A second compressor, a third condenser, a third expansion valve, a third evaporator, and a low temperature cycle circuit continuously connected to the second compressor are further configured, and the second condenser and the third evaporator are counterflow heat exchangers. Vacuum lyophilizer adopting heat pump method characterized by mutual heat exchange The method according to any one of claims 1 to 3, A second evaporator is further provided immediately in front of the first compressor in each circuit of the freezing cycle of the freeze-drying apparatus, and the second evaporator and the first condenser are heat-exchanged with each other to form a regeneration cycle. One vacuum lyophilizer The method of claim 5, In the freezing cycle of the freeze drying device, the self-freezing circuit may include a first compressor, p1 pipe, p2 pipe, A1 solenoid valve, p3 pipe, p4 pipe, first condenser, p5 pipe, second condenser, p6 pipe, and A2 electron. Vacuum freezing employing a heat pump method characterized by a continuous configuration of the valve, the first expansion valve, the hot plate, the p8 pipe, the A3 solenoid valve, the p9 pipe, the p10 pipe, the second evaporator, the p11 pipe, and the first compressor. Drying device The method of claim 5, The hot plate temperature rise and cold trap temperature maintaining circuit of the freeze-drying device of the freeze-drying apparatus is specifically designed for the first compressor, p1 pipe, p2 pipe, B1 solenoid valve, p12 pipe, hot plate, p8 pipe, B3 electron valve, p13 pipe, p4 Piping, 1st condenser, p5 piping, 2nd condenser, p6 piping, B2 solenoid valve, 2nd expansion valve, p14 piping, cold trap, p15 piping, p10 piping, second evaporator, p11 piping, again to the first compressor Vacuum freeze drying apparatus employing a heat pump method characterized by having a subsequent configuration The method of claim 7, wherein Cold trap cooling and temperature holding circuit of the freeze-drying device of the freeze-drying apparatus is specifically a first compressor, p1 pipe, p2 pipe, A1 solenoid valve, p3 pipe, p4 pipe, the first condenser, p5 pipe, the second condenser, The heat pump method is characterized by having a configuration continuously connected to the p6 pipe, the B2 solenoid valve, the second expansion valve, the p14 pipe, the cold trap, the p15 pipe, the p10 pipe, the second evaporator, the p11 pipe, and the first compressor. One vacuum lyophilizer The method of claim 1, The freeze cycle of the freeze-drying apparatus is further provided with a cold trap defrost cycle, the defrost cycle is continuously connected to the first compressor, the first condenser, the cold trap, the third expansion valve, the hot plate, and again to the first compressor. Vacuum lyophilizer adopting the characteristic heat pump method The method of claim 5, The third condenser of the low temperature cycle circuit is a vacuum freeze-drying apparatus employing a heat pump method characterized in that the contact is installed so as to exchange heat with the second evaporator of each circuit of the refrigeration cycle.

Images