KR20030047612A - dehumidifying method and system in cold-hot air dry condition - Google Patents

Abstract

PURPOSE: A dehumidifying method and device in hot and cold air dry condition is provided to reduce drying hours, and improve thermal efficiency. CONSTITUTION: An air compressing pump(b), condensers(a1,a2,a3), a refrigerant compressor, a refrigerant tank, an evaporator, and refrigerant condensers(c,d) are installed in a drying room(s) insulated from the outside. A dehumidifying device compresses air, condenses humidity, and reuses the heat of condensation generated by condensing the humidity as heating.

Description

Dehumidifying method and system in cold-hot air dry condition

Drying is the removal of moisture by applying heat to the dry matter. The method of drying while removing the vaporized vapor from the dry matter is related to the efficiency of heat use in terms of drying time and heat used during drying. It is a direct factor. It is also a problem directly related to drying temperature, the most sensitive part of drying.

In the case of hot air dryers and cold air dryers using air, the method of removing the vaporized water vapor from the dried material is as follows.

The hot air dryer induces evaporation by heating the dry matter while circulating hot air through the blower. At this time, in the removal of the vaporized steam, there is an air opening and closing opening in the upper part of the dryer, by opening the opening and closing the humidified air (including saturated steam) to the outside of the dryer to remove the steam. The drying phenomenon is that evaporation of water vapor occurs in the dried product until the atmosphere around the dry matter becomes the saturated steam pressure corresponding to each temperature.

The hot air dryer is a method of removing the steam by removing the humidified air out of the drying chamber, so that the drying conditions are frequently placed in the atmosphere of saturated steam pressure, in which case the additional vapor of the vapor from the dry matter in the saturated steam pressure atmosphere. Is not done.

When the humidity contained in the air being circulated is low, the moisture contained in the dry matter is well evaporated to dry quickly. In the case of a hot air dryer, a frequent humid air atmosphere is formed, so that the drying time becomes longer. In a humid environment, evaporation of moisture in the dry matter is stopped. In addition, since the opening and closing frequently open to remove the humid air, the heated air is forced out of the drying chamber such as steam, causing unnecessary heat loss.

In terms of energy use, in the case of hot air dryers, the boiler is operated to provide heat for evaporation of water, thereby heating the circulated air to provide heat. The heated air heats the building to generate water vapor, and the generated water vapor is discharged in an evaporated form into the atmosphere outside the drying chamber, so that heat must be continuously supplied, and the heat use efficiency is not more than 35%.

When evaporating 1 kg of water at 55 ° C, the theoretical calorie required (heat required to raise the specific heat from 20 ° C to 55 ° C with a specific heat of 1 + heat of evaporation => 30㎉ + 565㎉) is 595㎉, which is about the hot air dryer. 1605 열 of heat will be used. In other words, the hot air drying method has a problem in that the thermal efficiency is relatively low and the drying time is somewhat longer.

In the case of a cold air dryer, the drying method and drying temperature are as follows. In the drying chamber where air circulates, a refrigerant compressor, a refrigerant evaporator, and a refrigerant condenser are composed of circuits. By passing the circulating air with constant humidification through the refrigerant evaporator, the superheated steam cools the water vapor to condense. The air deprived of heat is dehumidified as much as the air cooled temperature. When the cooled air passes through the refrigerant condenser, it is heated, and the heated air is moved to the space where the object is to be dried to lower the relative humidity of the air circulated by being mixed with the circulated air. This process is continuously carried out to lower the humidity of the air circulated to dry.

The indoor pressure of the cold air dryer is the same as the normal atmospheric pressure, and the air is used as a heat transfer medium under the same atmospheric pressure, and the temperature of the air is reduced by heat exchange in an evaporator or a condenser to condense water vapor or heat the cooled air. Done. In the cold air drying process, the drying temperature condition of the drying chamber should actually be maintained at about 50 ° C or higher.

When the room temperature of the drying room is 32 ° C or lower, it is not easy to remove a certain amount of water vapor contained in this air to maintain a constant humidity in cold air drying conditions. The air containing 32 ° C saturated steam must be lowered to about 10 ° C to remove a certain amount of water, and the drying process can be performed. If a device can be dried to meet these conditions through a cold air dryer, Since the density is low and the heat transfer rate is low, the device of the evaporator and condenser that exchanges heat with air has to be enlarged. In this case, the cost of the device is too high and the economic reality is greatly reduced.

If the dried product containing 440kg of water is dried at 400kg of water under the above conditions, and the drying time is 40 hours, the installation area of the condenser and the evaporator may refer to the following conditions.

10kg of water vapor must be removed in 1 hour, which translates to 167g of water vapor in 1 minute. When 167g is saturated steam at 32 ° C, the pressure is 33.7torr and the volume is about 4.8m 3. However, if the temperature is 32 ° C., the internal steam pressure is about 60% humidity because dehumidified air is introduced. At this time, the water vapor pressure is about 20.2torr, and the volume of air containing 167g of water vapor is about 6.72m3. In other words, if the air with a humidity of 60% of 6.72m3 is lowered from 32 ℃ to 10 ℃ in 1 minute, the pressure of water vapor is lowered to about 9.2torr, and the amount of water vapor (22.8torr-9.2torr) is condensed at 13.6torr. This will be condensed. Therefore, to condense 167 g of water vapor in one minute, the actual amount of air to be cooled is 17.2 m 3 / min. In 1 second, 286 L of air should be lowered from 32 ° C to 10 ° C, and considering the heat transfer of air, it should be known that it should be very large, and it is found that there is no economic reality at all. Therefore, the actual drying temperature used in the cold air dryer is usually more than 50 ℃. There is no case of drying the dried object within 30 ℃ by using a cold air dryer, and it does not mean that the air is dried using cold air as the expression of cold air drying, and it does not supply additional energy. Some products in dry matters are subject to very sensitive drying temperatures. It may have a decisive influence on the quality of the product (nutrition, flavor preservation, pigment preservation), and it may be advantageous to dry it as low as possible, but even cold air drying within 20 ℃ or 10 ℃ in the cold air drying method There is a problem that the process cannot be performed.

In a drying apparatus that uses air in the atmosphere as a heat transfer medium, and circulates the air to heat and dry the dried object, it is generated when condensing in a condenser condensing water vapor by temporarily storing an air compression pump and compressed air in the drying chamber. It is equipped with a cooling device to cool the heat, compresses the air with a certain humidity in the drying chamber to condense a certain amount of water, and reuses the condensation heat generated when condensing to heat the dried material, thereby greatly reducing the drying time. The thermal efficiency is greatly improved, and the drying rate can be reduced by lowering the content rate of water vapor contained in the air during the drying process to any desired content rate, thereby making it possible to dry more than 98% of the moisture contained in the dry matter, and drying temperature 10 Drying is possible even below 占 폚. In addition, the compressor or blower using the electric power is operated in the drying chamber, and the power energy converted into heat during use is used as the drying energy, so that the heat lost by heat transfer to the outside of the drying chamber is used as the heat to be replaced. To minimize losses.

1 and 2 are circuit diagrams of the devices configured in the drying chamber.

Name of each code

a-1, a-2, a-3: condenser b: compression pump c: heat exchanger d: heat exchanger

e: Thermal fluid storage tank f: Circulation pump g: Evaporation chamber h: Blower

i: Steam diffusion port j: Drying chamber wall k: Condensate storage tank l: Compressed air line

m: Thermal fluid connector n: Circulation air connector o-1, o-2, O-3: Solenoid valve

p-1, p-2, p-3: solenoid valve q-1: cooling water inlet connector q-2: water outlet connector

r: Manual valve s: Drying chamber t: Refrigerant evaporator u: Refrigerant compressor

w: refrigerant liquid storage tank

Hereinafter, described in detail by the accompanying drawings as follows.

The cuboid of the rectangular parallelepiped having an internal volume of any desired size is formed by the insulated wall j so that the inside and the outside are completely blocked so that there is no air movement and no heat movement. The following devices are configured. The functions of each configured device have functions that are organically related to each other.

In the dry product containing 440 kg of moisture, 400 kg of dry matter is removed while leaving about 10% of the moisture. The evaporation chamber (g) contains the dry matter stacked in a tray, and the evaporation chamber (g) Air inlets and outlets are connected to the left and right sides of the blower (h) and the heat exchanger (d). In a blower (h) of 3 hp (2.2 kw / h) having a pressure of about 0.3 to 0.8 kg / cm 2, air with a constant pressure is sent to the evaporation chamber (g), In contact with or pass through, it exits through the outlet out of the evaporation chamber. The evaporation chamber (g) is connected as a passage of air and the inside of the pipe circulating only air, while the space inside the drying chamber and the space are not connected. The air exiting the evaporation chamber passes through the heat exchanger (d), passes through the water vapor diffusion port (i), flows back into the blower (h), and circulates. If the drying temperature is 55 ° C, it is important that the temperature of this circulating air is maintained at 55 ° C. The circulating air is continuously circulated until the end of the drying process, while the evaporation chamber (g) collides with the dry matter and passes, while water evaporation occurs in the dry matter and is cooled. The air at 55 ° C is cooled because it loses the heat of evaporation when water vapor evaporates. The function of heating this cooled air to maintain 55 degreeC is a blower and a heat exchanger (d).

The wind energy produced by the blower is converted into frictional heat and the air is heated, or heat is received by the heat exchanger (d). Water vapor contained in the air circulated through the blower (h) is diffused into the space of the drying chamber while passing through the vapor diffusion port (i), whereby the humidity and drying chamber (s) contained in the circulating air The humidity contained in the air is the same. The steam diffusion port (i) serves to keep the humidity constant by mixing the air in the drying chamber (s) and the air in the evaporation chamber (g), while the air passing through the diffusion port (i) passes, while some are in the drying chamber. Air is mixed with the air and discharged into the drying chamber.

The principle that the heat source of the heat exchanger (d) that provides heat to the circulating air is generated as follows.

When water vapor evaporates from the dry matter and diffuses into the drying chamber s, the humidity of the drying chamber s becomes high and the humidity rises by 90% or more. At this time, a compression pump (b) having a suction amount of 2.4 m 3 and a horsepower of 3 hp (2.2 kw / h) is operated to be sent to the condenser (a-1, a-2, a-3) at a pressure of about 8 kg / cm 2. Since the air entering the condenser is pressurized, it reaches a temperature of over 100 ° C. and is cooled to 63 ° C. while staying in the condenser. The heat transfer medium contained in the storage tank (e) flows into the heat exchanger tube formed in the condenser (a-1, a-2, a-3) in accordance with the operation of the circulation pump (f) at a temperature of 55 ℃ In this case, the pressurized compressed air is cooled and raised to 60 ° C. At this time, the circulation pump (f) is operated until the end of the drying process to circulate the heat medium liquid. The compressor (b) condenses a large amount of water vapor and leaves only saturated steam corresponding to 63 ° C. 90% of the water vapor enters the condenser and is reduced in volume by 1/8, so most of it is condensed. For example, at 55 ° C and 90% humidity, if 4 ㎥ of air is compressed to reduce the volume to 500 l, the amount of condensed water vapor and the amount of water vapor remaining are as follows.

Saturated water vapor pressure at 55 ℃: 118torr

90% humidity, pressure: 106.2torr

Water vapor amount at 55 ℃, 90% humidity of 4㎥ volume: 360g

Saturated water vapor at 500 ℃ and 63 ℃: 77g

· The amount of water vapor cooled by condenser after compression: 360g-77g = 283g

(Initial amount of water contained in compressed air-amount of residual water after condensation = amount of water vapor condensed)

Humidity when the water vapor in compressed 500ℓ air is partially condensed and then re-expanded to a temperature of 4㎥ and 55 ℃.

Therefore, the water vapor condensed in the condenser condenses about 81% of the water vapor introduced into the condenser, and the residual amount is 77g and the condensation amount is 283g.

On the other hand, the air cooled in the condenser (a-1, a-2, a-3) passes through the solenoid valve (p-1, p-2, p-3) to the outside of the condenser. As the air expanded while going out of the connecting pipe is expanded and the pressure is lowered, the temperature is drastically lowered, and the low temperature air is passed through the heat exchanger c to raise the temperature. After raising the temperature as described above is sent out to the drying chamber (s). When the humidity of the drying chamber is 40% of the desired humidity, when the temperature reaches 40%, the operation of the compressor (b) is stopped to remove the water vapor from the drying chamber, and after a certain time, when the humidity reaches 90%, the compressor Just run (b) again.

The heat medium liquid circulated through the circulation pump (f) is maintained at 55 ° C in the storage tank (e) and raised to 60 ° C in the condensers (a-1, a-2, a-3), and then blower (h) Heat is supplied through the heat exchanger (d) to the circulating air passing through the evaporation chamber. It provides heat of about 3 to 4 ° C., passes through the heat exchanger (c), provides about 2 ° C. of heat to the cooling air, and enters the storage tank (e). This heat medium liquid is safe to use water.

As the drying process continues, the internal temperature of the drying chamber increases with time. In the use of this device, the heat cannot be released to the outside but stored inside.

Heat is used to evaporate the steam, but when condensing the water vapor again provides heat of condensation to the air of the drying chamber, so that heat does not flow out of the drying chamber, and the heat of condensation is reused as the evaporation heat during drying. Heat is used as air heating heat, which is converted into heat of evaporation of moisture, which is then converted into heat of condensation, which heats the air. Therefore, heat is not lost but can be recycled and reused. The power energy used to drive the blower, the circulation pump and the compressor remains in the drying chamber and is converted into a heating source, thereby increasing the temperature of the drying chamber.

At this time, the function of properly maintaining the temperature allows the cooling water to flow in from the cooling water inlet line (q-1) connected to the storage tank (e), and discharges the water used as the heat medium liquid at 55 ° C of the storage tank (e) to the outside. It is a function of the water outlet line (q-2). Except that there is a small amount of heat loss to the outside air in the drying chamber, the heat generated by the time is not discharged to the outside is as follows.

Circulating pump: 380w / h (electric power equivalent: 326.8㎉ / h)

Compressor: 2.2kw / h (Power equivalent calorie: 1892h / h)

Blower: 2.2kw / h (electric power equivalent: 1892㎉ / h)

Total power equivalent calorie: 4110.8㎉ / h

That is, 4110.8 ㎉ / h is surplus per hour, and in order to solve this problem, 117.5 kg of water, which is a 55 ° C. heating medium liquid, is discharged to the outside of the drying chamber in one hour, and the amount of water is dried at a temperature of about 20 ° C. ) Should be injected. This role is the cooling water inlet line (q-1) and the water outlet line (q-2). It is enough to drain and inflow about 2kg of water per minute.

On the other hand, condensate condensed in the condenser flows into the condensate storage tank (k), and the level of the condensate stored in the tank indicates the percentage of drying.

The air in the drying chamber is compressed by the compressor (b), sent to the condensers (a-1, a-2, a-3), condensed moisture, and then sent out of the condenser again as follows.

The humid air in the drying chamber is compressed by the compressor (b) and sent to the condenser (a-1). This condenser (a-1) is a 300L / min, 8kg / ㎠ performance when the internal volume is 400ℓ, 8kg to the condenser (a-1) through the pipe connected to the solenoid valve (o-1) / Cm2 pressure. At this time, the time that all the air enters the condenser (a-1) takes about 1 minute 20 seconds. When all the air enters, the solenoid valve o-1 is closed. The solenoid valve p-1 is closed. At the same time the solenoid valve o-1 is closed, the solenoid valve o-2 is opened and compressed air enters the condenser a-2. At this time, the air enters the condenser (a-2) at the same speed and takes 1 minute and 20 seconds. When all the air enters the condenser a-2, the solenoid valve o-2 is closed. The function of closing or opening the solenoid valve is by a pressure sensor attached to the condenser. When the internal pressure of the condenser is set to 8kg / ㎠, the solenoid valve is operated.

The solenoid valve (o-2) is closed and at the same time the solenoid valve (p-1) and the solenoid valve (o-3) are opened, and the air contained in the condenser (a-1) is cooled for 1 minute and 20 seconds, In this condensed state to come out to the drying chamber outside the condenser (a-1). At this time, the elapsed time during the exit of the condenser (a-1) is controlled by the discharge amount of air through the manual valve (r) attached to the end of the pipe discharged so as to be within 1 minute. When the air is discharged, the internal pressure of the condenser a-1 is 1 kg / cm 2, and the solenoid valve p-1 is closed. Compressed air enters the condenser (a-3) and the solenoid valve (o-3) is closed.At the same time, the solenoid valve (o-1) opens and the compressed air is introduced again into the condenser (a-1). The solenoid valve p-2 is opened and the air contained in the condenser a-2 is cooled in a state where 1 minute and 20 seconds have elapsed and is discharged to the drying chamber. When air enters condenser a-1, the air in a-3 is exhausted, the air in a-2 is being cooled down, and when all the air in a-1 enters, the air in a-2 is exhausted The air contained in a-3 becomes cooling. As such, the three condensers are alternately introduced and discharged with air.

Thermal efficiency is greatly improved.

When performing a drying process using this apparatus, the heat utilization rate is as follows.

<Use calorie using this apparatus>

(400kg moisture dry weight for 40 hours when dried at 55 ℃)

Initial heating heat (heat to heat the dried product and the peripheral device at 25 ° C to 55 ° C)

Building heating heat

: 530kg × 30kcal (heat value rising from 25 ℃ to 55 ℃) × 1 (specific heat) = 15900kcal

Peripheral Heating Heat: 800kg × 0.3 (Specific Heat) × 30kcal = 7200kcal

Air heating in drying room: 51.7kg × 0.241 × 30kcal = 374kcal

Initial heating heat total: 23474kcal

Power source 4110.8 kcal × 40 hours = 164432 kcal

Total calories: 187906kcal

※ Reference

Initial heating heat refers to heat for heating the air and the dry matter in the drying chamber at 25 ° C. and peripheral devices installed in the drying chamber at 55 ° C.

Removes 400kg of water from 530kg of dry matter

Most dry items have a specific heat of less than 1 Kcal per 1 g, but the specific heat is calculated as 1

Peripheral equipment refers to the devices configured inside the drying room. The weight is less than 800kg and calculated as 0.3cal with 0.107cal or extra amount in 1g of iron specific heat.

When the air in the drying room is 40㎥, the weight is 51.7kg based on 0 ℃.

The power source is the power of two 3 horsepower and one 380 watts converted into calories

Air density is 1.293kg / ㎥ and specific heat is 0.241cal / g at 0 ℃

<Theoretical calories used for drying>

400kg moisture evaporation heat 565kcal

(Evaporation heat of 1kg of water evaporated at 55 ℃) × 400kg = 226000kcal

Initial heating heat (as above): 23474kcal

Total theoretical dry heat: 249474kcal

(Initial heating heat + 400kg moisture evaporation heat = total theoretical dry heat)

In other words, the thermal efficiency is about 130%.

When using this device, in the case of removing the moisture in the drying room, if the humidity is removed in the low humidity state, the driving energy of the compression pump is used more, and the thermal efficiency may be somewhat lower. Since the driving energy of the pump is used less, the thermal efficiency can be increased.

In addition, when the drying temperature is low during the drying process, the heat use efficiency is low, and when the drying temperature is high, the heat use efficiency is increased.

〈The amount of heat used to dry 1kg of moisture when comparing hot air drying to thermal efficiency〉

(When the temperature is 55 ℃)

Hot air dryer: 1605kcal

Theoretical calories: 595kcal

This technology: 469 kcal (under the same conditions as above)

When the drying temperature is 90 ℃ in the drying process, the heat use efficiency is greatly increased and it is as follows.

Since the pressure of the water vapor contained in the space is high, a large amount of water vapor can be condensed in operating the compressor, and the heat of condensation generated at this time can be used as the heat of evaporation.

For example, when a compressor with a discharge amount of 300 l / min / 3 Hp is used to compress and condense 90% of humidity at 90 ° C, the amount of water vapor condensed in one minute and the amount of heat of condensation are as follows.

〈Water vapor condensation and heat of condensation in 1 minute〉

Water vapor pressure: 570torr

Water vapor volume and mass: 2.3㎥ / kg

Volume capacity to condense in 1 minute: 2.4㎥

1 minute condensation: 800g

Non-condensing vapor amount remaining after condensation: 200g

1 minute condensation heat: 452kcal / min

〈Water vapor condensation and heat of condensation in 1 hour〉

Condensation Heat: 27120kcal (452Kcal × 60 minutes)

Water vapor: 48kg (800g × 60 minutes)

When the drying process is performed at 55 ° C., 5650 kcal (calorie amount of heat to evaporate and condense 10 kg of water vapor) per hour is circulated, so that it can be seen that there is a difference that circulates about 4.8 times the amount of energy.

<Thermal efficiency when drying 400 kg of moisture under the above conditions>

(Humidity: 90% Temperature: 90 ℃ Drying Time: 8 hours)

Initial heating heat (heat for heating air and dry items and peripheral devices in a drying chamber at 25 ° C to 90 ° C)

-530kg Heating: (25 ℃ dried) × 65kcal (65 ℃ rising heat) × 1 (specific heat) = 32500kcal

Peripheral device heating heat: 800kg × 65kcal × 0.3 (specific heat) = 15600kcal

-Air heating heat in drying room: (When 40㎥) 51.7kg × 0.241 × 65Kcal = 810kcal

Initial heating heat total: 48910kcal

〈Power amount and calorie converted amount〉

Compressor: 2.2kw × 8h = 17.6kwh (17.6kw × 860kcal = 15136kcal)

Blower: 2.2kw × 8h = 17.6kwh (17.6kw × 860kcal = 15136kcal)

Circulation pump: 380w × 8h = 3.04kwh (3.04kw × 860kcal = 2614kcal)

Total used calorific value: 32886kcal (15136 + 15136 + 2164kcal)

Total calories: 48910kcal + 32886kcal = 81796kcal

(Initial heating heat + total converted heat = total heat)

〈Theoretical calories used for evaporating 400kg at 90 ℃〉

Evaporation heat when evaporating 400kg at 90 ℃: 545kcal / kg × 400kg = 218000kcal

Initial heating heat: 48910kcal

Total theoretical calories: 48910kcal + 218000kcal = 266910kcal

(Initial heating heat + 400kg evaporation heat = total theoretical heat)

The thermal efficiency is about 320% when dried at 90 ° C using this apparatus.

〈Total Heat, Drying Time and Thermal Efficiency when Drying at 55 ℃ and 90 ℃〉

(Removes 400kg of moisture)

When dried at 90 ° C: 80986kcal, 8 hours, 320%

When dried at 55 ° C: 187532kcal, 40 hours, 130%

· The drying time is shortened.

In the hot air drying process, the air containing the humidified saturated steam is dehumidified in a manner that is discharged outside, so that the evaporation of moisture in the dry matter is stopped and the drying is delayed during the air humidified time.

As the humidity increases, the amount of evaporation of water decreases, so keeping the humidity low helps to shorten the drying time. By using this apparatus, when the average humidity is maintained at 50% during the drying process, the drying time can be dried by using 50 to 70% of the time compared to the hot air dryer when the drying time is compared with the hot air drying method. Hot air dryer is used for more than 60 hours when drying at 55 ℃, this device is used for 40 hours.

Low temperature drying is possible.

By applying this device, the drying process can be carried out even if the drying temperature is less than 10 ℃. As shown in Fig. 2, the connecting pipe through which the heat transfer medium flows is passed only through the condenser, and a separate cooling device is added to keep the temperature low. Can be. When the drying process is carried out at a drying temperature of 10 ° C., the saturated vapor pressure at 10 ° C. is 9.2 torr, so in order to condense the compressed air to 8 kg / cm 2 and make it into dry air, the temperature of the heat transfer medium passing through the condenser must be lowered. . In order to lower the humid air having a humidity of 90% and a temperature of 10 ° C to 10% of humidity, it is required to cool it to a low temperature of about 5 ° C while being pressurized at 8kg / cm 2. If the temperature of 5 ℃ is maintained at a pressure of 8kg / ㎠ it can be removed by condensing the moisture contained in the air more than 70%. In order to lower the temperature, the heat transfer medium must be passed through the refrigerant evaporator t configured in the cooling device to maintain the heat transfer medium below 1 ° C at all times. By circulating the heat transfer medium below 1 ℃, it is possible to maintain the compressed air below 5 ℃.

In the cooling system, the refrigerant compressed by the compressor (u) is sent to the condenser, which plays the role of the heat exchangers c and d. The refrigerant is evaporated in the evaporator (t), passes through the compressor (u) and is compressed, and then condenses as it passes through the condensers (c, d). The heat evaporated in the evaporator (t) receives heat transfer through the heat transfer medium circulated through the circulation pump (f), and when the refrigerant is condensed in the condensers (c, d), the heat of condensation is circulated through the air, It is discharged from the condenser (a-1, a-2, a-3) and expanded. By configuring the cooling device to use the cold heat of such a low temperature, it is possible to dry the dry matter even less than 10 ℃.

98% moisture can be removed.

When performing low temperature drying below 10 ℃, a separate cooling device is used. This cooling device is used, and the temperature of the compressed air compressed and condensed using this cooling device is condenser (a-1, a-). If the temperature is kept 0 ° C. or lower in 2, a-3), the air in the drying chamber is circulated in the evaporation chamber g at the end of the drying process as dry air with little humidity. Residual moisture contained in the dry matter is an atmosphere in which the humidity of the ambient air is less than 1%, so that evaporation is easily performed. Here, to keep the air in the condenser (a-1, a-2, a-3) below 0 ° C through the cooling device is to maintain the evaporation temperature of the refrigerant in the evaporator (t) within 0 ° C do. The removal of residual moisture contained in the dry items makes it possible to remove 98% of the water.The higher the drying temperature of the evaporation chamber, the faster the removal of residual water occurs.The difference between the drying temperature of the drying chamber and the condensation temperature condensed in the condenser The greater the temperature difference, the faster the removal of residual moisture.

Claims (2)

In the drying apparatus using air in the atmosphere as a heat transfer medium, the air is circulated to heat and dry the dried object, the air compression pump (b) and the compressed air in the interior (s) of the interior and heat-insulated drying chamber (s) A condenser that temporarily condenses water vapor, and a refrigerant compressor (u), a refrigerant liquid storage tank (w), an evaporator (t), and a refrigerant condenser (c, d), which are cooling devices for cooling the heat generated when condensing in the condenser. A dehumidifying method under cold and hot air drying conditions, wherein the air is compressed to condense a certain amount of moisture in the drying chamber to condense a certain amount of water, and the condensation heat generated when condensing is used to heat the dried material. A cuboid with an internal volume of any desired size is formed to be insulated and enclosed inside so that there is no air movement and heat movement with the outside, and air, which is a heating medium inside the user, is rubbed and contacted with the dry matter. A blower (h) that heats and circulates, an evaporation chamber (g) that is airtight and frictionally contacts and touches the dry matter, and stacks the dry matter therein; A heat exchanger (d) having a heating function and a vapor diffusion port (i) having a function of discharging steam into the drying chamber (s) are connected to the inlet of the blower (h), A compressor (b) for sucking and compressing air in the drying chamber, a condenser (a) having a function of condensing moisture by entering compressed air compressed by the compressor, and a heat exchanger (c) having a function of heating expansion air connected thereto Is composed of The water, which is a heat transfer medium that serves to transfer heat to the heated air circulated to the evaporation chamber (g) after circulating inside the condenser (a) and takes heat, is connected to the condenser (a) and the evaporation chamber (g). Device (d) and a closed circuit which is introduced into the storage tank (e) via a heat exchanger (c) for heating the expansion air and then flows back into the condenser (a) through the circulation pump (f). Dehumidifier in cold, hot air drying conditions, characterized in that configured to circulate in.