JPS6274435A - Air drying apparatus - Google Patents

Abstract

PURPOSE:To reduce required heat energy, by connecting a regenerating air take-in pipe and an exhaust pipe of high humidity air after regeneration action and mixing the open air with high humidity air after regeneration. CONSTITUTION:In a rotary dehumidifier, the place 28 ahead of the heater 22 of the regenerating air take-in pipe 21 of a dehumidifying rotor 1 is connected to the place 29 behind the blower heater 24 of an exhaust pipe 23 of high humidity air after having passed through a regeneration zone 2 by a connection pipe 27 and dampers 25, 26 are respectively provided to both pipes 21, 33. The taken-in open air Ao and high humidity air Aw to be exhausted are mixed in a desired ratio to be introduced into the heater 22 and heated to form regenerating air AH which is, in turn, passed through the regeneration zone 2. The high humidity air Aw after passed through the regeneration zone 2 is exhausted through the exhaust pipe 23 and a regenerating air blower 24 but a part thereof is guided to the take-in pipe 21 through the connection pipe 27 by the action of the dampers 26, 25 and mixed with the open air Ao to form mixed regenerated air AM.

Description

[Detailed Description of the Invention] Industrial Field of Use This invention can be used for dehumidifying air in rooms, factories, warehouses, etc., drying conveyed air, drying foods, medicines, electrical products, etc., and preventing moisture in articles. This invention relates to a particularly suitable air drying device.

A conceptual diagram of an air drying device using a conventional rotary dehumidifier is shown in FIG. It is provided with a regeneration air intake hopper 4 and a regeneration air discharge hopper 5, between which regeneration air heated by a heater passes through the rotor to regenerate the moisture absorbent.

The remaining part inside the rotor is moisture absorption zone 3.

Inside the moisture absorption rotor 1, activated carbon sheets with excellent adsorption properties are housed in a honeycomb shape as a moisture absorption body. The humid air Bw is introduced into the moisture absorbing sheath 73 of the dehumidifying rotor 1 through the filter 8, absorbs moisture and becomes dry air ad, which is drawn to the main blower 33 and circulated. The dehumidifying rotor 1 is rotated by a motor 6 and a belt 7 in the direction of arrow R in the figure, and the moisture absorbing bodies pass one after another through the regeneration zone 2 between the hoppers 4 and 5 and are regenerated.

On the other hand, the outside air Ao for regeneration is heated by the heater 22, passes through the regeneration zone from the regeneration air intake hopper 4, goes to the discharge hopper 5, is drawn to the regeneration air blower 24, becomes humid air AV, and enters the atmosphere. released.

FIG. 2 is an explanatory diagram of air flow in a conventional device, and the same reference numerals as in FIG. 1 represent the same parts. To explain the operation of the air drying device while showing an example of the air condition, assume that the outside air Ao has a temperature of 33°C and an absolute humidity of 19f, and the heater 22
Heated air for regeneration Ah (140℃19y/Kg(D
A)), the humid air passes through the regeneration zone 2 of the dehumidifying rotor 1 and after the regeneration action Aw(95℃30y/Kf(D
A)), which is drawn by the regeneration air blower through the exhaust pipe 23 and discharged into the atmosphere.

The air should be further dried (10℃, 51/Kz(
DA)) enters the moisture absorption zone 3 of the dehumidifying rotor 1 through the intake pipe 31, and the dry air ad(25°C, 1.3y/~(D
A)), which flows through the reflux pipe 32 by the main blower 33 and is refluxed into the room, warehouse, etc.

Outside air temperature tAh of regeneration air Ah N Absolute humidity "Ah Temperature t of humid air Aw after regeneration action, absolute humidity "Ay
'Temperature of the air aw to be dehumidified1.・Absolute humidity "aw"
``If the temperature of the dry air ad after dehumidification is 4, the absolute humidity is
xAWh is 30 p/Kf(DA), t is 10℃, xaW is 5W f/Kf(DA), t is 25℃, is 1.3f/a
d xad K9 (DA). (The amount of heat heated by the blower is small and can be ignored.) The relationship tA, -tAw 25-10 holds true.

In this conventional example, humid air after regeneration is released into the atmosphere5, which has the disadvantage of requiring a large amount of energy for heating and the like.

Means for Solving the Problems In the present invention, in order to eliminate the above-mentioned drawbacks, the part of the regeneration air intake pipe in front of the heater is connected to the humid air discharge pipe after the regeneration action, A damper is installed in each of the intake pipe and the discharge pipe to guide the regeneration air, which is a mixture of outside air and humid air after regeneration at the desired ratio, to the heater, making it an extremely energy-saving air dryer. The device was obtained.

Embodiment FIG. 3 is an explanatory diagram of the flow of air in the air drying apparatus 10 of the present invention, and the same reference numerals as in FIGS. 1 and 2 represent the same parts. In this invention, a portion 28 of the regeneration air intake pipe 21 in front of the heater 22 and a portion 29 of the humid air discharge pipe 23 after the blower 24 are connected by a connecting pipe 27, and the respective pipes are connected as shown in the figure. Damper before and after point 25.26
The outside air AO taken in and the humid air AW to be discharged are mixed in a desired ratio to produce mixed regeneration air AM.
It is introduced into the heater, heated by the heater 22, becomes regeneration air AH, passes through the regeneration sea 72, and becomes multi-sea air Aw.
The air is discharged through the exhaust pipe 23 and the regenerated air blower 24, but due to the action of the damper 26.25, a portion enters the intake pipe 21 through the connecting pipe 27 and mixes with the outside air Ao to form a mixed regenerated air bottom. . The position of the damper may be any position including (26') indicated by the dotted line in the figure. Further, the blower 24 may be installed before entering the dehumidifier.

To give an example of numerical values, Ao is 33℃, 19F/Kg (D
A) The temperature reached is 80.5℃, 55? /KLI(DA)
The temperature is 140℃, 55 f/KLl (DA), and the temperature is 95℃, 66 y/Kg (DA). In other words, in the conventional device, the outside air Ao was directly heated, so the temperature was 140℃-33℃.
'C=107℃, but in this invention, the mixed air AM
140℃-80.5℃=59.5℃59
．． 5, and the heating capacity is / = 0.556, which is 55.6% of that of the conventional device.

As mentioned above, this regenerated drying system is a dehumidifier drying system, and its drying rate is expressed by the formula % (1) where W: Dry moisture content t: Time h k: Partial pressure group Single substance 9/'tT in the transfer coefficient? h m H
g: Surface area of the object to be dried - P': Water vapor pressure Hg corresponding to the wet bulb temperature of air P: Water vapor partial pressure of air mHg.

In equation (1), kX'' is a constant for the object to be dried, so the drying power of the air is expressed as (p'-p).
Showing the difference between '-P, P' (Ah) = 71.90 P (Ah) = 22.5
3P'(Ah)-P(Ah)=49.37p'(AI(
)=108.3 P(AH)=61.741'(A
H) - P (AI) = 46.56 Therefore, the drying power of AH is 94.3% of Ah, but the heating energy is <55.6% as mentioned above, resulting in extremely energy saving as a whole. .

Next, assume that the dehumidification load for setting Bw to ad becomes %. In the conventional device, Ah is 110° C. in such a case. Since the outside air AO was set to 33℃, the amount of heating was 110-33=
77, and when the dehumidification load is 1 as mentioned above, Ah is 14
Since the temperature is 0°C, 140-33=107, and even if the dehumidification load is %, the heating energy is 77/1o7=0.
At 72, it only goes down to 72%. However, with the device of this invention, the temperature reached is 80.5°C, so 110-80.5=2
9.5: 29.5/77 Ki: 0.4, approximately 40% of conventional equipment
That's fine.

In general, if controllability is poor at partial loads, energy consumption will increase. Electric heaters and steam heaters are used as heaters.

In the case of a steam heater, proportional control is possible, but in the case of an electric heater, either on/off control or step control is performed. In the case of on/off control, the temperature of the regeneration air is repeatedly changed between 140° C. (Ah or AH) and the outside air temperature (Ao), and the state of the dehumidified air is repeatedly changed from one extreme to another. In this invention, AH (
140℃) to Aw (80,5tZ”) and gradually 0
approach. If the two Dans and ξ- shown in FIG. 3 are closed and all the air is circulated, the temperature will be kept at about AM, and so-called heat shock can be alleviated.

Effects As described above, the air drying apparatus of the present invention has a simple structure and can reduce the required thermal energy without reducing the drying capacity.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an air drying apparatus, FIG. 2 is an explanatory diagram of the air flow in the conventional apparatus, and FIG. 6 is an explanatory diagram of the air flow in the apparatus of the present invention. Explanation of symbols 1...Moisture absorption eater, 2...Regeneration zone, 3.
・・Moisture absorption zone 4・・Intake hot spring 2-15・・
・t5t[j4:tsu, e-16...motor, 7...
・Belt, 8...Filter, 21...Intake pipe, 2
2...Heater, 26...Discharge pipe, 24...Blower 125, 26...Dan/e-127...Connecting pipe, 31...Intake pipe, 32...Recirculation pipe. \-111-n Figure 1 5 2 Drawing procedure amendment January 6, 1986

Claims (1)

[Claims] In an air drying device using a rotary dehumidifier, connect the regeneration air intake pipe in front of the heater and the regeneration air exhaust pipe, and connect the regeneration air intake pipe and the regeneration air exhaust pipe. An air drying device characterized in that a damper provided in a pipe guides regeneration air, which is a mixture of regenerated air and outside air in a desired ratio, to a heater.