KR20190105559A - Infrared freeze drying system - Google Patents

Abstract

The present invention relates to an infrared freeze drying system. The purpose of the present invention is to increase a sublimation dry speed by radiant energy while maintaining vacuum by having an infrared lamp in a freeze dryer. According to an embodiment of the present invention, the infrared freeze drying system includes: a drying chamber accommodating an object to be frozen and dried; a vacuum pump enabling the drying chamber to be in a vacuum state; a freezing trap connected between the drying chamber and the vacuum pump and absorbing moisture of the inside of the drying chamber; an infrared lamp installed in the drying chamber and providing radiant heat to the object; a drying period sensing unit for sensing time in which a constant-rate drying period on the object is changed to a falling-rate drying period; and a lamp operation control unit controlling the operation of the infrared lamp in accordance with a sensing result of the drying period sensing unit.

Description

Infrared freeze drying system {INFRARED FREEZE DRYING SYSTEM}

The present invention relates to an infrared freeze drying system.

Freeze drying is a technology widely used in the production of foods and medicines, and unlike hot air drying using high temperature, the technology of drying by preliminary freezing (-30 ~ -50 ° C) through sublimation under vacuum (4.58 torr or less) to be.

Freeze-dried foods and medicines do not use heat, so they do not destroy useful ingredients, nutritional and sensory values in foods and medicines. In this case, the restoration rate is restored to its original state and is very excellent, and it is widely used for making noodles, such as cup soup or instant soup.

The freeze-drying technique has the advantages as described above, but the problem is that the drying time is much longer than 48 hours, the disadvantage is low productivity and significant cost.

In the early stage of freeze-drying, sublimation drying occurs on the surface as a rate drying process, and the sublimation drying rate tends to be high. Since the beginning of the rate reduction drying process, since the internal moisture is sublimated while moving to the outside shows the rate reduction drying process (48 hours or more) is slow.

If the sublimation heat can be supplied during the rate reduction drying process, the drying rate can be increased very rapidly. The supply of sublimation heat should be careful not to thaw the pre-frozen food while maintaining the vacuum. It is not available because it has low delivery efficiency and can thaw food.

An alternative method is to provide the sublimation heat through the infrared lamp, but the infrared lamp provides the radiant energy in the vacuum state during the freeze-drying process to supply the sublimation heat at an appropriate intensity, so that the frozen food does not thaw. .

An embodiment of the present invention provides an infrared freeze-drying system that can install an infrared lamp inside the freeze dryer to maintain a vacuum and increase the sublimation drying rate by radiant energy.

Infrared freeze drying system according to an embodiment of the present invention, the drying chamber for receiving a lyophilized object; A vacuum pump for vacuuming the interior of the drying chamber; A freezing trap connected between the drying chamber and the vacuum pump to absorb moisture in the drying chamber; An infrared lamp installed inside the drying chamber and providing radiant heat to the object; A drying period detecting unit for detecting a time point of switching from the constant drying period to the reduction rate drying period for the object; And a lamp operation control unit controlling an operation of the infrared lamp according to a detection result of the drying period detection unit.

In addition, the drying period detection unit, the electronic scale for measuring the weight of the object is installed inside the drying chamber; A PID (Proportional Integral Derivative) controller which calculates a differential coefficient by differentiating an amount of change of the weight of the object measured through the electronic balance into a drying time; A data collector configured to collect data on the differential coefficients calculated by the PID controller and detect whether the differential coefficients are reduced by a predetermined value or more; And a deceleration drying time determination unit for determining a reduction time of the differential coefficient as a transition time from the constant drying period to the deceleration drying period when the differential coefficient is detected to be reduced by a predetermined value or more through the data collection unit.

The lamp operation control unit may control the operation of the infrared lamp in a PID (Proportional Integral Derivative) method when the switching from the constant drying period to the reduction rate drying period is detected through the drying period detecting unit.

The apparatus may further include the temperature sensor installed inside the drying chamber and measuring the temperature inside the drying chamber and transmitting the temperature sensor to the drying period detecting unit. The lamp operation controller may include a temperature value received through the drying period detecting unit in advance. When the set temperature is equal to or greater than the first reference temperature value, the operation of the infrared lamp may be stopped, but may be stopped until the preset second reference temperature value or less is reached.

In addition, the first reference temperature value may be set higher than the second reference temperature value.

The lamp operation controller may adjust the first reference temperature value and the second reference temperature value by adjusting the supply voltage of the infrared lamp.

According to the present invention, by installing an infrared lamp inside the freeze dryer, it is possible to maintain the vacuum and increase the sublimation drying rate by the radiant energy.

1 is a block diagram showing the overall configuration of an infrared freeze drying system according to an embodiment of the present invention.
2 is a graph showing the switching time between the period drying period and the reduction rate drying period according to an embodiment of the present invention.
3 is a photograph of an infrared freeze drying system implemented according to an embodiment of the present invention.
Figure 4 is a photograph showing the power consumption according to the use of the infrared freeze drying system according to an embodiment of the present invention through an electric charge meter.

Terms used herein will be briefly described and the present invention will be described in detail.

The terms used in the present invention have been selected as widely used general terms as possible in consideration of the functions in the present invention, but this may vary according to the intention or precedent of the person skilled in the art, the emergence of new technologies and the like. In addition, in certain cases, there is also a term arbitrarily selected by the applicant, in which case the meaning will be described in detail in the description of the invention. Therefore, the terms used in the present invention should be defined based on the meanings of the terms and the contents throughout the present invention, rather than the names of the simple terms.

When a part of the specification is said to "include" any component, this means that it may further include other components, except to exclude other components unless specifically stated otherwise. In addition, the terms "... unit", "module", etc. described in the specification mean a unit for processing at least one function or operation, which may be implemented in hardware or software or a combination of hardware and software. .

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

1 is a block diagram showing the overall configuration of the infrared freeze drying system according to an embodiment of the present invention, Figure 2 is a graph showing the switching time between the period drying rate and the rate reduction drying period according to an embodiment of the present invention, Figure 3 Is a photograph of an infrared freeze drying system implemented according to an embodiment of the present invention.

1 to 3, the infrared freeze drying system 100 according to an embodiment of the present invention is a drying chamber 110, vacuum pump 120, freezing trap 130, infrared lamp 140, drying period detection The unit 150, the lamp operation control unit 160 and the temperature sensor 170.

The drying chamber 110 provides a sealed space for receiving the freeze-dried object 10, the inside may be provided with a shelf that can accommodate the freeze-dried object (10) or a support means that can be mounted. In the present embodiment, the freeze-dried object 10 may be a pre-frozen food, but is not limited thereto and may apply various objects.

The vacuum pump 120 is a means for discharging the gas inside the drying chamber 110 to make the interior of the drying chamber 110 in a vacuum state, and may control to make a predetermined degree of vacuum. As the vacuum pump 120, various vacuum pumps, such as a rotary pump or a dry pump, may be used.

The freezing trap 130 may be installed in the exhaust path between the drying chamber 110 and the vacuum pump 120, so that more water vapor present in the drying chamber 110 can be collected.

The infrared freeze drying system 100 of the present embodiment operates the vacuum pump 120 to make the interior of the drying chamber 110 in a vacuum state, and the freeze-drying object 10 is dried by sublimation to generate moisture. The moisture may be moved to the freeze trap 130 to dry the freeze-dried object 10.

The infrared lamp 140 may be installed inside the drying chamber 10 and may provide radiant heat to the lyophilized object 10. In FIG. 1, the infrared lamp 140 is illustrated as being installed in the ceiling of the drying room, but the present invention is not limited thereto, and the infrared lamp 140 may be installed at various locations. The plurality of infrared lamps 140 may include a lamp operation controller 160. Can be controlled by the on / off, and the number, time and pattern of the lamps on / off may also be controlled.

In addition to the function of controlling the on / off by the lamp operation control unit 160, the infrared lamp 140 may control the voltage intensity applied to the infrared lamp 140 according to the set temperature.

The drying period detecting unit 150 may detect a time point of switching from a constant rate of drying to a falling rate drying period for the object. To this end, the drying period detection unit 150 may include an electronic balance 151, a PID (Proportional Integral Derivative) controller 152, a data collection unit 153, and a reduction rate drying time determination unit 154.

The electronic balance 151 may be installed in the drying chamber 110 to measure the weight of the object 10. The electronic balance 151 may be connected to the PID controller 152 to transmit real-time weight data of the object 10 to the PID controller 152.

The PID controller 152 may calculate a differential coefficient by differentiating an amount of change in the weight of the object 10 measured by the electronic balance 151 as a drying time. That is, the PID controller 152 calculates the slope of the change in weight of the object 10 relative to the drying time.

The data collection unit 153 may detect whether the differential coefficient is reduced by a predetermined value or more by collecting data on the differential coefficient calculated by the PID controller 152. For example, if 100 g of sample is dried, the slope (derived coefficient) calculated during the constant drying period is Y = -0.2 · X + 100, and the slope (derived coefficient) is Y = -0.03 at the start of reduction rate drying The slope may be abruptly reduced to X + 100, and when the decrease of the slope is detected, the detected data (the differential coefficient value or the slope value) may be transmitted to the rate reduction dry point determining unit 154.

When the deceleration coefficient is determined to be reduced by more than a predetermined value through the data collection unit 153, the deceleration drying time determination unit 154 converts the decrement time from the constant drying period to the deceleration drying period. You can judge. In this way, it is possible to more accurately determine the time of transition to the reduction rate drying period by setting the reference variation amount of the derivative.

The lamp operation control unit 160 may control the operation of the infrared lamp 140 according to the detection result of the drying period detecting unit 154. More specifically, the lamp operation control unit 160, when the conversion from the constant drying period to the reduction rate drying period is detected or determined through the drying period detecting unit 150, the operation of the infrared lamp 140 PID (Proportional Integral) Derivative) can be controlled on / off.

In addition to the on / off control, the PID method may control the intensity and temperature of the lamp by adjusting the voltage value in the on state.

The temperature sensor 170 is installed in the drying chamber 110, and measures the temperature inside the drying chamber 110 and transmits the temperature to the drying period detecting unit 150. In order to prevent thawing of food due to excessive sublimation heat during the infrared freeze-drying period, when the internal temperature of the drying chamber 110 is measured by the temperature sensor 170 and the predetermined temperature is higher than the predetermined temperature, the infrared lamp 140 is controlled through the lamp operation control unit 160. By adjusting the on / off and the voltage value can be adjusted so as not to provide excessive sublimation heat to the lyophilized object (10).

In this case, the lamp operation controller 160 stops the operation of the infrared lamp 140 when the temperature value received through the drying period detecting unit 1 is equal to or greater than the first reference temperature value, and the preset second reference temperature. It can be stopped until it is below the value. Here, the first reference temperature value may be set higher than the second reference temperature value, which is to ensure a sufficient temperature difference between the on / off and voltage regulating operation of the infrared lamp 140. The lamp operation control unit 160 may adjust the supply voltage of the infrared lamp 140 to set the first reference temperature value and the second reference temperature value to be adjustable during operation of the infrared lamp 140.

Figure 4 is a photograph showing the power consumption according to the use of the infrared freeze drying system according to an embodiment of the present invention through an electric charge meter. More specifically, (a) of FIG. 4 is a photograph of measuring power consumption of the vacuum pump 120 and the freezing trap 130 of the infrared freeze drying system 100, and (b) of the infrared lamp 140. This picture shows the power consumption.

Infrared freeze drying system 100 according to the present embodiment can reduce the drying speed more than two times compared to the conventional drying system, and in the economic analysis of power consumption, as a result of the experiment, when operating the 24-hour infrared freeze dryer, vacuum While the pump 120 and the refrigeration trap 130 consumed 13.3 kWh of power, the infrared lamp 140 consumed 0.5 kWh of power, and thus the power consumption of the infrared lamp 140 is negligible. Since it is low, the economics of operation of a device can be improved.

What has been described above is just one embodiment for carrying out the infrared freeze drying system according to the present invention, and the present invention is not limited to the above embodiment, and as claimed in the following claims, the gist of the present invention Without departing from the scope of the present invention, any person having ordinary skill in the art will have the technical spirit of the present invention to the extent that various modifications can be made.

100: infrared freeze drying system
110: drying chamber
120: vacuum pump
130: Frozen Trap
140: infrared lamp
150: drying period detection unit
151: electronic balance
152: PID controller
153: data collector
154: rate reduction drying point determination unit
160: lamp operation control unit
170: temperature sensor
10: lyophilized object

Claims (1)

A drying chamber for receiving a lyophilized object;
A vacuum pump for vacuuming the interior of the drying chamber;
A freezing trap connected between the drying chamber and the vacuum pump to absorb moisture in the drying chamber;
An infrared lamp installed inside the drying chamber and providing radiant heat to the object;
A drying period detecting unit for detecting a time point of switching from the constant drying period to the reduction rate drying period for the object; And
And a lamp operation control unit for controlling the operation of the infrared lamp according to the detection result of the drying period detecting unit.

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