JP3300565B2 - Low dew point air supply system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low dew point air supply system.

[0002]

2. Description of the Related Art For example, in a semiconductor manufacturing process,
The demand for dry and low dew point dry room equipment is increasing. And in this type of conventional dry room,
A low dew point air supply system as shown in FIG. 3 is used. The following system is an example in which the dry-bulb temperature in the dry room R is 23 ° C. and the dew point temperature is −32 ° C.

[0003] That is, the introduced outside air (QOA) is cooled by the first pre-cooler 101 and then cooled by the first dehumidifier 1.
02 and the second by the dehumidifying blower 103
It is transferred to the precooler 104. Then, the dehumidified processing air is further transferred to the second dehumidifier 106 by the dehumidification blower 105 and subjected to dehumidification processing. Thereafter, a part of the dehumidified air (QDA) that has passed through the second dehumidifier 106 is returned to a purge section 106c of the second dehumidifier 106, which will be described later, as purge air (QP). After the temperature is adjusted by the aftercooler 107, the air is supplied to the dry room R, which is the destination room.

[0004] The dehumidified air supplied to the dry room R is:
Part of it (pressurized P: amount of air to keep the room at positive pressure)
Is discharged outside the room, and the remainder is transferred to the second pre-cooler 104 as return air (QR).

The first dehumidifier 102 is a rotary dry dehumidifier having a large dehumidifying capacity, and includes a honeycomb-shaped rotor impregnated with an absorbing solution such as lithium chloride or calcium chloride;
The end face of the rotor made of an adsorbent such as silica gel or zeolite is partitioned into a dehumidification area 102a and a regeneration area 102b.
The dry air is produced by passing the treated air through the air, and the high-temperature regenerated air is passed through the regenerating section 102b, thereby evaporating the water in the absorbent and the adsorbent into the regenerated air, thereby continuously reducing the humidity. It is configured to perform processing. Also, the second dehumidifier 106 basically has the structure of a rotary dry dehumidifier having the same operation and effect as the first dehumidifier 102. 106 is a purge zone 1 in addition to the dehumidification zone 106a and the regeneration zone 106b.
06c.

[0006] The purge zone 106c is provided in the regeneration zone 10
6b and the dehumidification area 106a, and according to the rotation direction of the rotor, as shown in FIG.
The configuration is such that the rotor elements correspond in the order of the purge area 106c → the dehumidification area 106a. Therefore, the residual heat of the high-temperature absorbent and the adsorbent immediately after passing through the regeneration section 106b is removed by the purge air (QP) in the purge section 106c.

The purge air (QP) heated through the purge section 106c is divided into four parts, and a part of the purge air (QP) is mixed with the dehumidified air that has passed through the first dehumidifier 102 by a regeneration blower 108. Then, it is transferred to the inlet side of the second pre-cooler 104, partly mixed with introduced outside air (QOA) at the inlet side of the pre-cooler 101, and partly supplied to the regeneration heater 109 by the regeneration blower 108. And transferred
The remaining part is transferred to the regeneration heater 110. Then, the air heated through the regeneration heater 109 is regenerated air (QRH1) as regeneration air (QRH1) in the regeneration zone 10 of the second dehumidifier 106.
6b. On the other hand, the air heated through the regeneration heater 110 is supplied as regeneration air (QRH2) to the regeneration section 102b of the first dehumidifier 102, and the air whose temperature has decreased is dehumidified as exhaust gas (EA). The water is discharged to the outside by the regenerating blower 111 together with the moisture.

[0008]

However, in the conventional low dew point air supply system, in addition to the second dehumidifier 106 for circulating air in the dry room R, regeneration air (QRH1) and regeneration air (QRH2) are used. And purge air (Q
P) And a first dehumidifier 102 for pre-dehumidifying the pressurized amount P for the dry room R is provided. This type of rotary dehumidifier is expensive, so that initial costs such as equipment costs have risen. In addition, the flow rates of the regeneration air (QRH1) and regeneration air (QRH2) for regenerating these two dehumidifiers are the same as those of the original purpose, that is, the circulation dehumidification air (QDA) for supplying to the dry room R. The air volume reaches about 40% of the air volume, and the air volume of the purge air (QP) also increases with the regeneration air (QRH1) +
Since half of the regeneration air (QRH2) was required, the energy consumption as a whole was extremely large. Further, in the conventional system, since the regeneration air (QRH1) (a part of the purge air (QP)) for regeneration of the first dehumidifier 102 is exhausted, the air amount of the introduced outside air is increased by the pressurized amount. It is necessary to add P to the amount of the exhaust gas (EA).

The present invention has been made in view of the above points, and in a low dew point air supply system for supplying to a dry room or the like, the efficiency of a dry dehumidifier is improved and the effective use of purge air is improved. It is therefore an object of the present invention to provide a system that can simplify the equipment to reduce the number of dehumidifiers (the number of stages) and also reduce the energy consumption required for dehumidification, and to solve the above problem. I do.

[0010]

According to the present invention, there is provided a system for supplying low-dew point air to a target room using a rotary dry dehumidifier. The dehumidifier has an air passage area located on the rotor end face,
In the order of rotation of the rotor, it is divided into a regeneration zone, a high-temperature purge zone, a low-temperature purge zone, a dehumidification zone, and a regeneration entrance zone, and the target chamber is configured to be supplied with air that has passed through the dehumidification zone. A portion of the low-humidity return air from the destination chamber is configured to pass in the order of the high-temperature purge section → the regeneration inlet section → the low-temperature purge section of the rotary dry dehumidifier,
The low dew point is characterized in that the air that has passed through the low-temperature purge zone is mixed with the introduced outside air and used again as processing air that passes through the dehumidification zone of the rotary dry dehumidifier. An air supply system is provided.

In such a low dew point air supply system,
As described in claim 2, the regeneration air passing through the rotary dry dehumidifier is configured to circulate in a system different from the system of the air passing through the high-temperature purge section or the like. This moisture may be removed by a cooling and dehumidifying device provided in the regeneration air system.

[0012]

According to the present invention, a part of the return air from the target chamber, that is, a part of the low dew point air, passes as the purge air in the order of the high temperature purge area, the regeneration inlet area, and the low temperature purge area of the rotary dry dehumidifier. It is configured as follows. Therefore, when passing through the high-temperature purge section, the residual heat of the dehumidifier, which has become high in the regeneration section, is first removed. Then, the purge air heated by the heat exchange at this time passes through the regeneration inlet area of the dehumidifier, and the heat is used as preheating before entering the regeneration area. Thereafter, the purged air having passed through the regeneration inlet section and having a lowered temperature is subjected to heat exchange when passing through the low-temperature purge section, and the residual heat is further removed before the rotor element enters the dehumidification section. Therefore, the dehumidifying efficiency in the early stage of the dehumidifying zone is improved, and the regenerating efficiency in the initial stage of the regenerating zone is improved, so that the efficiency of the whole rotary dry dehumidifier is improved. The air that has passed through the low-temperature purge zone is, for example, cooled and mixed with the introduced outside air, so that the air can be effectively used without being exhausted.

According to the present invention, the regeneration air is circulated in a system different from the system of the air passing through the high-temperature purge section or the like, and the moisture in the regeneration air is provided in the regeneration air system. Was removed by the cooling and dehumidifying device.
There is no need to introduce outside air to heat the regeneration air. In addition, a regeneration inlet section is provided in front of the regeneration section, through which the heated purge air is passed and preheated, so that the energy required for heating the regeneration air can be reduced.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows a low dew point air supply system according to the present embodiment. The present embodiment is configured as a system for supplying low dry point air to the dry room R. The system according to the present embodiment is an example in which the dry bulb temperature in the dry room R is 23 ° C. and the dew point temperature is −32 ° C.

First, the introduced outside air (OA) is cooled through the pre-cooler 1 and then transferred to the dehumidification section 3a of the dehumidifier 3 by the dehumidification blower 2. As shown in FIG. 2, the dehumidifier 3 is a rotary dry dehumidifier having a large dehumidifying capacity by rotating a rotor 4. The rotor 4 is made of an absorbent such as lithium chloride or calcium chloride. May be impregnated to form a honeycomb shape, or an adsorbent such as silica gel or zeolite may be housed inside the rotor 4. In any case, the air passing through the dehumidifying section 3a of the dehumidifier 3 is configured to be dehumidified by the absorbing liquid, the adsorbent, and the like.

As shown in FIG. 2, the dehumidifier 3 has five air passage areas. That is, in the order of the rotation direction of the rotor 4, the regeneration section 3b through which the regeneration air passes, the high-temperature purge section 3c, and the low-temperature purge section 3
d, the above-mentioned dehumidification area 3a, and the regeneration entrance area 3e.

The dehumidified air (QDA) dehumidified by passing through the dehumidification section 3a is cooled to a predetermined temperature, for example, 3 ° C. to 12 ° C. in the aftercooler 5, and then supplied to the dry room R. You. A part of the pressure P, which is a part of the pressure, is discharged outside the room. The remaining part is transferred to the pre-cooler 1 as return air (QR), and the other part is transferred to the high-temperature purge section 3c of the dehumidifier 3 as purge air (QP).

The return air having a low dew point, that is, the purge air (QP) transferred to the high-temperature purge section 3c of the dehumidifier 3 removes residual heat of the rotor 4 which has a high temperature in the regeneration section and purge air. (QP) itself is heated by the heat exchange at that time, and is then transferred to the regeneration inlet section 3e of the dehumidifier 3.

In the regeneration inlet section 3e, the rotor 4 is preheated by the passage of the heated purge air (QP) before entering the regeneration section 3b, and the temperature of the purge air (QP) decreases by heat exchange at that time. Then, it is transferred to the low-temperature purge section 3d of the dehumidifier 3 this time. Then, in the low-temperature purge section 3d, residual heat in the low-temperature portion of the rotor 4 is removed by passing the purge air (QP) whose temperature has been lowered.

Thereafter, the purge air (QP), which has been heated by passing through the low temperature purge section 3d, is sent by a purge blower 6 to, for example, a cooling water coil 7 of a cooling tower, and is supplied to the cooling water coil 7 for about 40 minutes.
Cool down to ° C. That is, the purge air (QP) is heat-exchanged by the cooling water coil 7 of the cooling tower with the return-radiated cooling water on the return side. Then, the purge air (QP) air cooled by the cooling water coil 7 is returned to the inlet side to the preceding precooler 1. By thus lowering the temperature of the purge air (QP) before returning to the precooler 1, efficiency is further improved. In such a case, by using the cooling water of the cooling tower as in the present embodiment, the purge air (QP) is cheaper than using, for example, the cold water of a refrigerator.
Temperature can be lowered. The cooling tower itself,
What is used for the refrigerator used for cooling the refrigerant such as the precooler 1 can be used. When the temperature of the purge air (QP) is reduced before returning it to the precooler 1, another cooling means, for example, an air-cooled heat exchanger can be used.

On the other hand, the regeneration air of the dehumidifier 3 circulates in a system different from the circulation system of the dry room R described above. That is, the regeneration air (QRH) heated by the regeneration heater 11 is supplied to the regeneration section 3 b of the dehumidifier 3.
And transferred to a heat exchanger, for example, a rotary total heat exchanger 13 by a regenerative blower 12. The regenerated air (QRH) cooled down through the rotary total heat exchanger 13 is further cooled by the cooling dehumidifier 14 to remove water.
Then, the regenerated air (QRH) cooled there is transferred to the rotary type total heat exchanger 13, where the heat is exchanged and the temperature is raised. Then, the regenerated air (QRH) is transferred to the regenerating heater 11 and circulates. I have.

The low dew point air supply system according to the present embodiment is configured as described above. According to the knowledge of the inventor, the same level of dry room R as that of the system according to the above-described prior art is provided at the same level. It has been found that this embodiment can sufficiently supply air with a low dew point.
In the system according to the present embodiment, the dehumidifier has a single-stage configuration, and the equipment costs and the like are lower than before by that much. The removal of the moisture dehumidified by the dehumidifier 3 is based on the cooling dehumidifier 14 provided on the outlet side of the regeneration air.
The recycled air is recycled without being discharged.
Therefore, the energy required for regeneration is lower than that of the conventional system. The amount of regeneration air (QRH)
1/3 to 1/5 of dehumidified air (QDA), purge air (Q
The amount of P) is half the amount of regeneration air (QRH), and the system can be operated.

In particular, the dehumidifier 3 divides the air passage area into five areas, and the regeneration area 3b, the high temperature purge area 3c, the low temperature purge area 3d, the aforementioned dehumidification area 3a, and the regeneration inlet area through which the regeneration air passes. 3e, and has a low dew point return air from the dry room R as a purge gas.
Since the gas passes through the high-temperature purge section 3c, the regeneration inlet section 3e, and the low-temperature purge section 3d, the dehumidification efficiency in the dehumidification section 3a is improved, and the regeneration efficiency in the regeneration section 3b is also improved. Therefore, the efficiency of the dehumidifier 3 is higher than that of the conventional dehumidifier, and a low dew point air supply system having a one-stage dehumidifier configuration can be realized.

The system of the regenerating air is different from the system of the circulating air in the dry room R.
Since P) is not exhausted to the outside and its effective utilization is achieved, the amount of air of the introduced outside air (QOA) may be only the pressurized amount P after all. Therefore, the amount of introduced outside air can be smaller than that of the above-described conventional technology.

[0025]

According to the present invention, the efficiency of the rotary dry dehumidifier is improved, and its effective use can be achieved without introducing outside air as purge air. In the case where it is necessary to use a rotary dry dehumidifier in two stages to supply low dew point air, this can be reduced to one stage. Therefore, the equipment is simplified, the equipment cost can be reduced, and the energy consumption can be reduced. In particular, in the case of claim 2, the system is configured to circulate the regeneration air in a system different from the system of the air passing through the high-temperature purge zone or the like, and the moisture in the regeneration air is provided in the regeneration air system. Since it was removed by a cooling and dehumidifying device, introduction of outside air as regeneration air was unnecessary,
In addition, since the regeneration inlet section is provided before the regeneration section and is preheated, the amount of energy required for heating the regeneration air can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing a configuration of a low dew point air supply system according to an embodiment of the present invention.

FIG. 2 is an axial front view of a dehumidifier used in the low dew point air supply system of FIG.

FIG. 3 is an explanatory view schematically showing a configuration of a low dew point air supply system according to a conventional technique.

FIG. 4 is an axial front explanatory view of a dehumidifier used in the low dew point air supply system of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Precooler 3 Dehumidifier 3a Dehumidification area 3b Regeneration area 3c High temperature purge area 3d Regeneration inlet area 3e Low temperature purge area 11 Regeneration heater 14 Cooling dehumidifier R Dry room

Claims (2)

(57) [Claims] 1. A system for supplying air having a low dew point to a target room by using a rotary dry dehumidifier, wherein the rotary dry dehumidifier has an air passage area located at an end face of the rotor, the air passage area of the rotor being It is divided into five sections of a regeneration section, a high-temperature purge section, a low-temperature purge section, a dehumidification section, and a regeneration entrance section in the direction of rotation, and the target chamber is supplied with air that has passed through the dehumidification section. A part of the return air from the chamber is configured to pass in the order of the high-temperature purge section → the regeneration inlet section → the low-temperature purge section of the rotary dry dehumidifier, and the air that has passed through the low-temperature purge section is introduced outside air. A low dew point air supply system, wherein the low dew point air supply system is configured to be used as process air that is mixed with water and passed again through the dehumidification section of the rotary dry dehumidifier. 2. The regeneration air passing through the rotary dry dehumidifier is configured to circulate in a system different from the air system passing through the high-temperature purge section or the like, and the moisture in the regeneration air is
The low dew point air supply system according to claim 1, wherein the system is configured to be removed by a cooling and dehumidifying device provided in the regeneration air system.