JP2000300935A - Dry dehumidifying system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply air with an ultra-low dew point of -80 deg.C or lower to a target space by a little quantity of energy by using a dry dehumidifying device without making the pressure in a rotor negative. SOLUTION: Dry dehumidifying devices 10, 20, 30 are systematically connected in series over three stages and a part of air issuing from the dehumidifying region 11a of a first stage rotor 11 is dehumidified in the dehumidifying region 21a of a second stage rotor 21 and a part of dehumidified air is further dehumidified in the dehumidifying region 31a of a third stage rotor 31 and subsequently heated and cooled to be supplied to a low dew point space S. A part of the remaining air issuing from the dehumidifying region 11a of the rotor 11 is introduced into the purge region 21c of the rotor 21 to be mixed with the air passed through the regenerating region 31b of the rotor 31 to be introduced into the regenerating region 21b of the rotor 21. A part of the remaining air issuing from the dehumidifying region 21a of the rotor 21 is introduced into the regenerating region 31b of the rotor 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dehumidification system used for supplying low dew point air to a target space, and more particularly, to reducing the processing air by passing the processing air through a rotatable rotor. The present invention relates to a dry dehumidification system using a dry dehumidifier.

[0002]

2. Description of the Related Art There is a cooling and dehumidifying method as a commonly used method for dehumidifying air.
Only the above air can be formed, and it cannot cope with a low dew point (−50 ° C. or less). Therefore, a dry dehumidifier using a rotary rotor is used as an air conditioner for supplying such low dew point air. The dry dehumidifier has a honeycomb-shaped rotor impregnated with an absorbing liquid such as lithium chloride or calcium chloride, or a rotor composed of an adsorbent such as silica gel or zeolite, and the air passage area located on the end face of the rotor. That is, for example, the passage area of the air by a partition such as a chamber disposed on the end face of the rotor is divided into a dehumidification area and a regeneration area, and the processing air is passed through the dehumidification area while rotating the rotor to produce dry air, By passing high-temperature regeneration air through the regeneration section, the moisture in the adsorbent is evaporated into the regeneration air, and the dehumidification process is performed continuously.

In this case, when the rotor moves to the dehumidification zone while the temperature is high, the processing air passes through the rotor without dehumidification and raises the dew point. A purge area for cooling the rotor by passing air through the air may be set between the regeneration area and the dehumidification area.

[0004] When a low dew point is obtained by such a dehumidifier using a rotary rotor, since there is a limit in lowering the dew point temperature in one stage, that is, alone, when a lower dew point is obtained, There is known a method of operating a two-stage type, that is, two dry dehumidifiers connected in series. JP-A-1-199621 discloses an example in which a low-dew point is obtained with a single-stage dehumidifier by devising a duct connection using a single-stage rotor. However, the lowest dew point temperatures obtained with these devices are on the order of -80C. That is, hitherto, it has not been possible to achieve a dew point temperature of −80 ° C. or less even with a dry dehumidifier using a rotary rotor.

Therefore, a low dew point lower than that, ie, -80
As a method of obtaining so-called ultra-low dew point air at a temperature of not more than ° C, a method using an adsorption tower called a pressure swing dehumidification method is known. In this method, the raw air is compressed by a compressor to remove the drain in the air, and then passed through an adsorption tower containing an adsorbent. According to a method using a pretreatment device of a cryogenic separation plant, which is an example using this method, the water concentration is adjusted to 10 to 20 pp.
b (the dew point temperature was -101 ° C to -98 ° C).

[0006]

However, in the pressure swing dehumidification method, large power is required to compress air first, and purified air is separately used for regeneration of the adsorbent in the adsorption tower. Energy consumption is large, the equipment is enlarged, and the running cost is very large.

The present invention has been made in view of the above circumstances, and provides a new dry dehumidification system for realizing an ultra-low dew point of -80 ° C. or less with less energy consumption than before and solves the problem. Its purpose is to achieve.

[0008]

According to a first aspect of the present invention, there is provided a system for supplying low dew point air to a target room using a dry dehumidifier, comprising the following arrangement. It is characterized by having. First, dry dehumidifiers for passing process air through a rotatable rotor to dehumidify the process air are connected in series in three stages, and the air dehumidified by the first stage dry dehumidifier is removed by two stages. The air is dehumidified by the dry dehumidifier in the second stage, and the air dehumidified by the dry dehumidifier in the second stage is dehumidified by the dry dehumidifier in the third stage. 2 above
The dry dehumidifiers of the third and third stages each have a configuration in which processing air is passed through a rotatable rotor to dehumidify the processing air, and an air passage area located on an end face side of the rotor. Are divided into a dehumidification zone, a regeneration zone, and a purge zone, and the respective zones are arranged so that the purge zone is positioned before the rotation of the rotor moves from the regeneration zone to the dehumidification zone. The air dehumidified by the first-stage dry dehumidifier is diverted and a part of the air is introduced into the purge zone of the second-stage dry dehumidifier, and the air that has passed through the purge zone is After being mixed with the air that has passed through the regeneration section of the third-stage dry dehumidifier, the mixed air is introduced into the regeneration section of the second-stage dry dehumidifier. Is configured to be introduced into the dehumidification area of the second-stage dry dehumidifier. The air that has passed through the dehumidification area of the second-stage dry dehumidifier is diverted and a part of the air is introduced into the purge area of the third-stage dry dehumidifier, and the air that has passed through the purge area is also separated. Is configured to be introduced into a regeneration area of the third-stage dry dehumidifier, and another part of the diverted air is introduced into a dehumidification area of the third-stage dry dehumidifier. It is configured to: The air passing through the dehumidification area of the third-stage dry dehumidifier is introduced into the target room.

In this case, as described in claim 2, a part of the return air from the destination chamber is separated from the air passing through the dehumidification section of the second-stage dry dehumidifier before the diversion. Or a portion of the return air from the destination chamber is passed through the dehumidification area of the first-stage dry dehumidifier, and may be configured to be mixed. You may comprise so that it may be mixed before the said division | segmentation.

According to the dry dehumidification system having such a configuration,
First, dry dehumidifiers are connected in series in three stages, and the air dehumidified by the first stage dry dehumidifier is dehumidified by the second stage dry dehumidifier, and then the third stage dehumidifier is used. Since the dehumidification is performed by the dry dehumidifier, it is possible to produce air having an extremely low dew point of -80 ° C or less.

In addition, not only the three-stage dry dehumidifier is connected in series, but also the air dehumidified by the first-stage dry dehumidifier is diverted, and a part of the air is divided into the second-stage dry dehumidifier. While being introduced into the purging section of the humidifier, the air that has passed through the purging section is mixed with the air that has passed through the regeneration section of the third-stage dry dehumidifier to regenerate the rotor of the second-stage dry dehumidifier. The air introduced into the section and passed through the dehumidifying section of the second-stage dry dehumidifier is diverted, and a part of the air is introduced into the purge section of the third-stage dry dehumidifier, and The air that has passed through the zone is configured to be introduced into the regeneration zone of the third-stage dry dehumidifier, and another part of the diverted air is reduced by the third stage of the dry dehumidifier. Since it is configured to be introduced into the wet area, the heater for heating the regeneration air It is possible to reduce the amount. In addition, since the humidity of air used for regeneration of the rotor of the second-stage dry dehumidifier is lower than that of the related art, the performance of the rotor of the second-stage dry dehumidifier itself is improved. Therefore, also from this point, it is possible to produce ultra-low dew point air while saving energy.

At the inlet of the regeneration section of each of the second and third dry dehumidifiers, the air that has diverted before passing through the rotor of each stage and passed through the purge section may be directly mixed (2). Since it is introduced into the regeneration zone (third-stage dry dehumidifier) or the regeneration zone (third-stage dry dehumidifier), it is possible to minimize the pressure loss when passing through the rotor. Therefore, as will be described in an embodiment described later, a positive pressure state can be realized at the entrance of the regeneration section. Therefore, it is possible to prevent the invasion of moisture from other parts into the rotors of the second and third stages of the dry dehumidifiers, and to perform a suitable regeneration.
In addition, a decrease in the dehumidifying ability can be prevented.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows a system of a dry dehumidification system according to a first embodiment. This dry dehumidification system includes a target low dew point space S
The system is configured to supply air with an ultra-low dew point of -80 ° C or lower.

The outside air OA as the raw material air is guided to the processing system duct 1, and is first cooled and dehumidified by the outside air processing cooler 2. The cooled and dehumidified air is then mixed with the purged air cooled by the outside air treatment cooler 2 and having passed through the purge section 11c of the rotor 11 of the first-stage dry dehumidification device 10.

As shown in FIG. 2, the first-stage dry-type dehumidifier 10 has chambers 1 at both ends of a rotating rotor 11.
2 and 13 are arranged. Each chamber 1
Each of the partitions 2 and 13 has three partitioning plates 14, 14 and 14 arranged radially therein, and partitions the space inside the chambers 12 and 13 into three. Correspondingly, the dehumidifying area 11a, the regenerating area 11b, and the purging area 1 are arranged on the end face of the rotor 11 in the order of rotation of the rotor 11 as shown by the thin arrows in FIG.
Three air passage areas 1c are defined. A dehumidification outlet 12a, a regeneration inlet 12b, and a purge outlet 12c for connecting to a duct or the like are formed on the outer end surface of the chamber 12 corresponding to each of these sections. The outer end face of the chamber 13 is also provided with a dehumidification inlet 13a, a regeneration outlet 13b, and a purge inlet 13c corresponding to the three areas.
Are respectively formed. The rotor 11 is impregnated with a hygroscopic material used for this type of rotor, such as lithium chloride, silica gel, and zeolite. Rotor 1
1 has a thickness of 400 mm, and the rotation speed of the rotor 11 is 6 revolutions / hour.

As described above, the first-stage dry dehumidifier 1
The air mixed with the purge air of the rotor 11 is supplied by the outside air processing fan 3 to the first-stage dry dehumidifier 10.
For example, through the dehumidification area 11a of the rotor 11, the dew point temperature is reduced to -35 ° C.

The air that has passed through the dehumidifying section 11a of the rotor 11 of the first-stage dry dehumidifier 10 is guided to the processing fan 4, cooled by the pre-cooler 5, and then diverted. It is guided to the purge area 21c of the rotor 21 of the dry dehumidifier 20 of the stage, and then mixed with the air that has passed through the regeneration area 31b of the rotor 31 of the dry dehumidifier 30 of the third stage, as described later. Second stage dry dehumidifier 20
The rotor 21 is guided to the regeneration area 21b. Another part of the diverted air is guided to the dehumidifying area 21a of the rotor 21 of the second-stage dry dehumidifying device 20.

The second-stage dry dehumidifier 20 has basically the same configuration as the first-stage dry dehumidifier 10,
1 are arranged in the order of the rotation direction of the rotor 21 in the dehumidifying area 21a, the regenerating area 21b, and the purging area 21c, which are processing areas.
Are divided into three air passage areas. The air that has passed through the dehumidifying section 21a of the rotor 21 of the second-stage dry dehumidifying device 20 is dehumidified to, for example, air having a low dew point of -75 ° C.

The air that has passed through the dehumidifying section 21a of the rotor 21 of the second-stage dry dehumidifier 20 is then guided to the processing fan 6 and cooled by the precooler 7, and then diverted upstream of the rotor 21. Then, a part thereof is led to the purge section 31c of the rotor 31 of the third-stage dry dehumidifier 30. Another part of the diverted air is
Dehumidification area 31 of rotor 31 of third-stage dry dehumidifier 30
a.

The third-stage dry dehumidifier 30 has basically the same configuration as the first-stage dry dehumidifier 10 and the second-stage dry dehumidifier 20, and the end face of the rotor 31 is In the order of the rotation of the rotor 31, the rotor 31 is divided into three air passage areas, namely, a dehumidification area 31a, a regeneration area 31b, and a purge area 31c, which are processing areas. The air that has passed through the dehumidifying section 31a of the rotor 31 of the third-stage dry dehumidifying device 30 is dehumidified, for example, to an ultra-low dew point of -90 ° C to -110 ° C. ing.

The air that has passed through the dehumidifying section 31a of the rotor 31 of the third-stage dry dehumidifier 30 is heated by a heating coil (not shown) or cooled by a cooling coil (not shown) as required. After being set to the desired temperature by cooling or the like, the air is conveyed to the low dew point space S as the air supply SA through the air supply duct 8.

After being cooled by the precooler 7, the air is branched upstream of the rotor 31 and introduced into the purge section 31 c of the rotor 31 of the third-stage dry dehumidifier 30 to cool the rotor 31. Then, after being heated by the regeneration heater 41, it is guided to the regeneration section 31b of the rotor 31 by the regeneration fan 42, whereby the regeneration of the rotor 31 is performed.

Since the air that has passed through the regeneration section 31b of the rotor 31 of the third-stage dry dehumidifier 30 has low humidity and high temperature, it is used for regeneration of the rotor 21 of the second-stage dry dehumidifier 20. Can be. In the present embodiment, the temperature is further increased by the second-stage regeneration heater 44 to increase the temperature.
As described above, since the air that has passed through the regeneration section 31b has low humidity and high temperature, the capacity of the regeneration heater 44 may be small.

On the other hand, the air guided to the purge section 21c of the rotor 21 of the second-stage dry dehumidifier 20
After being cooled, the air is mixed with the air heated by the regeneration heater 44 and guided to the regeneration area 21 b of the rotor 21 of the second-stage dry dehumidifier 20 by the regeneration fan 45. It is used for playback. As described above, the capacity of the second-stage regenerating heater 44 can be reduced, and the humidity of air used for regenerating can be reduced to 2
Since the rotor 21 of the second-stage dry dehumidifier 20 can be lower than the stage type, the performance of the rotor 21 is improved as compared with the conventional case.

The air that has passed through the regeneration section 21b of the rotor 21 of the second-stage dry dehumidifier 20 and exited from the outlet is heated again by the regeneration heater 46, and is regenerated by the regeneration fan 47. 10 are guided to a regeneration section 11b of the rotor 11 and used for regeneration of the rotor 11, and then the exhaust EA
Is discharged as On the other hand, since the purge air that has passed through the purge section 11c of the rotor 11 is air having a relatively low outlet temperature and low humidity, the purge air is cooled again by using a part of the outside air processing cooler 2 through the purge duct 48. ,
It is mixed with the outside air OA and used as processing air.
D1 to D4 in FIG. 1 are dampers appropriately interposed in the duct to adjust the air volume.

The return air RA1, RA from the low dew point space S
2. RA3 is the corresponding return air duct 51, 52, 53
Respectively, mixed with the introduced outside air OA on the upstream side of the outside air processing cooler 2, mixed with the air dehumidified in the dehumidifying section 11a of the first-stage dry dehumidifier 10, and further dried in the second-stage dry The air is mixed with the air dehumidified in the dehumidifying section 21a of the dehumidifying device 20 and can be freely introduced into the dehumidifying sections of the rotors 11, 21, and 31. These are the dampers D5, D6,
The selection is made by opening and closing D7.

The dehumidification processing system according to the present embodiment is configured as described above. As described above, the air after being cooled and dehumidified by the outside air processing cooler 2 is subjected to the first-stage dry reduction. The dehumidification is performed in the dehumidification section 11a of the wet device 10, and the dew point temperature is reduced to, for example, -35C. Next, after being cooled and dehumidified by the precooler 5, the dehumidification is further reduced by the dehumidification section 21a of the second-stage dry dehumidifier 20, and the dew point temperature is reduced to, for example, -75C. After being cooled and dehumidified again by the precooler 7, the dew point temperature is further lowered to -90 ° C to -110 ° C by the dehumidifying section 31a of the third-stage dry dehumidifying device 30. The air whose dew point temperature has been lowered to the ultra-low dew point as described above is then supplied to the target low dew point space S as an air supply SA after the temperature is adjusted by heating and cooling as required.

Therefore, even a system using a dry dehumidifier using a rotor, which has been impossible so far, can realize such an ultra-low dew point of -80 ° C. or less.

Further, in the present embodiment, before passing through the second-stage rotor 21 and the third-stage rotor 31, the flow is divided and introduced into the purge sections 21c and 31c. Since the air is mixed with the passed air and introduced into the regeneration area 1b of the second-stage rotor 21 or introduced into the regeneration area 31b of the third-stage rotor 31, the wind path is reduced when the rotor passes. The number of passages is small, and the pressure loss is reduced accordingly. Therefore, a positive pressure state can be realized at the entrance of each of the regeneration sections 21b and 31b.

For example, as shown in FIG. 3, after passing through the dehumidifying section 31 of the third-stage rotor 31, it is branched and introduced into the purge section 31c, and then compared with the case where the heating is performed by the regeneration heater 41, Such a result is obtained. Now, the pressure loss of the rotor 31 is set to 450 Pa in the dehumidification section 31a, 500 Pa in the regeneration section 31b, and 350 Pa in the purge section 31c.
In the system shown in FIG. 3, when the pressure of the processing air is 550 Pa when the air is blown by the processing fan 6 and passes through the precooler 7, the pressure becomes 100 Pa when the air passes through the dehumidification area 31 a. After that, the pressure becomes -250 Pa at the time when the gas passes through the purge section 31c, and the pressure becomes negative at the entrance of the regeneration section 31b.
If the pressure is negative, moisture may intrude from the outside and enter, and an ultra-low dew point may not be obtained.

As shown in FIG. 3, in order to maintain a positive pressure at the inlet of the regeneration section 31b using a system that introduces air that has passed through the dehumidification section 31a into the purge section 31c, the dehumidification section 31b is used.
A part of the air that has passed through a may be further diverted and introduced into the regeneration section 31b as it is, but then the air with an ultra-low dew point that has passed through the dehumidification section 31a will be further recycled. Therefore, the air volume must be increased, which results in high energy consumption, which is not practical.

According to this embodiment, the dehumidification area 3
Before the gas is introduced into 1a, the gas is separated and introduced into the purge area 31c. Therefore, when the gas passes through the purge area 31c, the positive pressure is still maintained at 200 Pa. Therefore, there is no possibility that moisture will enter the inside of the rotor 31 from the outside, and an ultra-low dew point can be suitably obtained.

In addition, since the return air from the low dew point space S can be used by being mixed with the processing air, the energy saving effect can be obtained from this point as well.

In the above embodiment, the dry dehumidifiers 10, 20, and 30 in each stage have basically the same configuration. However, the dry dehumidifier 10 in the first stage is exceptional. It is not necessary to use the same dry dehumidifiers 20, 30 in the second and third stages.

[0035]

According to the dry dehumidification system of the present invention, air having an extremely low dew point of -80 ° C. or less can be obtained by using a dry dehumidification device.
It can be manufactured with less energy and compact equipment than before. Further, since the rotor of the dry dehumidifier can be maintained at a positive pressure, there is no risk of moisture entering from the outside, and it is possible to suitably supply ultra-low dew point air.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing a configuration of a dry dehumidification system according to an embodiment of the present invention.

FIG. 2 is a perspective view of a rotor portion of a first-stage dry dehumidifier used in the dry dehumidifier system of FIG. 1;

FIG. 3 is an explanatory diagram showing pressure loss at each point in a system that divides a flow by passing through a dehumidifying section of a rotor.

FIG. 4 is an explanatory diagram showing pressure losses at various points around a third-stage dry dehumidifier in the system of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Dry dehumidifier (1st stage) 11 Rotor 11a Dehumidifier area 11b Regeneration area 11c Purge area 20 Dry dehumidifier (2nd stage) 21 Rotor 21a Dehumidifier area 21b Regeneration area 21c Purge area 30 Dry dehumidifier ( 3rd stage) 31 Rotor 31a Dehumidification area 31b Regeneration area 31c Purge area D1 to D7 Damper S Low dew point space

Claims (3)

[Claims] A system for supplying low dew point air to a target room using a dry dehumidifier, comprising: a dry dehumidifier for passing process air through a rotatable rotor to dehumidify the process air. Are connected in series in three stages, and the air dehumidified by the first-stage dry dehumidifier is dehumidified by the second-stage dry dehumidifier, and the air is dehumidified by the second-stage dry dehumidifier. Is configured to be dehumidified by a third-stage dry dehumidifier. The second-stage and third-stage dry dehumidifiers each pass process air through a rotatable rotor to process the air. The air passage area located on the end face side of the rotor is divided into a dehumidification area, a regeneration area, and a purge area, and the rotation of the rotor shifts from the regeneration area to the dehumidification area. Each of these sections is arranged so that the purge section is located before the first step. The air dehumidified by the humidifier is diverted and a part of the air is introduced into the purge section of the second-stage dry dehumidifier, and the air passing through the purge section is dried by the third-stage dry dehumidifier. After being mixed with the air that has passed through the regeneration section of the humidifier, it is configured to be introduced into the regeneration section of the second-stage dry dehumidifier, and another part of the diverted air is supplied to the second stage. The air passing through the dehumidifying section of the second-stage dry dehumidifier is diverted, and a part of the air is introduced into the third-stage dehumidifying section. The air introduced into the purge zone of the dry dehumidifier and the air having passed through the purge zone is introduced into the regeneration zone of the third stage dry dehumidifier, and the air other than the separated air is A part of the gas is introduced into the dehumidification area of the third-stage dry dehumidifier, The air that has passed through the dehumidification area is configured to be introduced into the destination chamber,
Dry dehumidification system. 2. A part of the return air from the destination chamber is
2. The dry dehumidification system according to claim 1, wherein the dry dehumidification system is configured to be mixed with the air that has passed through the dehumidification section of the stage of the dry dehumidification device before the branch flow. 3. 3. A part of the return air from the destination chamber is
3. The dry dehumidification system according to claim 2, wherein the dry dehumidification system is configured to be mixed with the air that has passed through the dehumidification section of the dry dehumidification unit of the first stage before the branch flow.