Gas Processing Equipment

Abstract

To provide a gas treatment device which can sufficiently desorb even when only small energy is provided into a regeneration zone and achieve low energy consumption.SOLUTION: In a gas processing device, an adsorption rotor 1 is divided into at least an adsorption zone 2, a preheating zone 5, a regeneration zone 4, and a cooling zone 3 in a written order in its rotation direction. The gas processing device causes a process gas to flow through the adsorption zone 2 and the cooling zone 3 in the same flow direction, supplies the gas which has passed through the adsorption zone 2 to a supply destination as a supply gas, and causes the gas which has passed through the cooling zone 3 to flow into the preheating zone 5 in the same flow direction as the process gas. Then, the gas processing device mixes the gas which has passed through the preheating zone 5 with outside air and causes the mixed gas to flow through a regeneration heater 8 and pass through the regeneration zone 4 in a direction opposite to a process gas flow direction as a regeneration gas.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a gas treatment device that consumes less energy. [Background technology]

[0002] As one type of gas treatment equipment, adsorption dehumidifiers can supply air with a lower dew point than refrigeration dehumidifiers, and are therefore popular in plants that require low dew point air, such as pharmaceutical and lithium battery plants. As this type of equipment becomes more popular, there is also a growing demand for reducing energy consumption, and various improvements have been made to this technology.

[0003] One of the means for reducing energy consumption is to provide a purge zone after the regeneration zone to recover excess desorption energy. The means described in Patent Documents 1 and 2 provide a preheating zone (second purge zone) in addition to a purge zone (first purge zone) (since there are various names for the various zones of the adsorption rotor, the zone where adsorption processing is performed will be referred to as the "adsorption zone" and the zone where regeneration or desorption is performed will be referred to as the "regeneration zone").

[0004] The system described in Patent Document 1 circulates air so that it alternates between air leaving the preheating zone (second purge region) and air leaving the purge zone (first purge region), and uses a portion of the treated air that has been dehumidified and has a low humidity content as regeneration air, thereby reducing the energy required to heat the regeneration air and the energy required to cool the treated air before dehumidification, thereby keeping the energy consumption of the entire system low.A regeneration air flow path is provided for sending a portion of the treated air after dehumidification to the adsorbent rotor as the regeneration air.A regeneration air flow path is provided for sending a portion of the treated air after dehumidification to the adsorbent rotor as the regeneration air.

[0005] In the method described in Patent Document 2, the dehumidification rotor is preheated by air whose temperature has increased by passing through the purge zone, so that sufficient desorption can be achieved even with little energy input into the regeneration zone, resulting in a high energy-saving effect.

[0006] As described above, each of the patent documents discloses that energy saving and efficiency can be achieved by providing zones before and after the regeneration zone. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 6839235 [Patent Document 2] Patent No. 5805978 Summary of the Invention [Problem to be solved by the invention]

[0008] The system described in Patent Document 1 requires a circulation fan (purge fan) to circulate air alternately between the first purge region and the second purge region. In addition, since a preheater is provided before air is introduced into the second purge region, the preheating effect on the second purge region is enhanced, but the cooling effect on the first purge region is sacrificed, and the effect of improving the dehumidification performance of the entire system cannot be expected.

[0009] In the device described in Patent Document 2, the air volume passing through the purge zone, preheating zone, and regeneration zone is the same, so if the optimal air volume required for regeneration and the optimal air volume required for purging differ, one of them must be sacrificed, and maximum dehumidification performance may not be achieved.

[0010] In view of the above circumstances, the problem to be solved by the present invention is to realize the demand for a greater energy saving effect than the techniques disclosed in the above documents. Note that, in this application, dehumidification using an adsorbent that adsorbs moisture in gas is mainly described, but the present invention is not limited to this. By using zeolite or activated carbon that adsorbs volatile organic compounds (VOCs) as the adsorbent, VOCs can be the object of adsorption. In addition, by using an amine-supported solid absorbent or a copper catalyst as the adsorbent, carbon dioxide or oxygen can be the object of adsorption. [Means for solving the problem]

[0011] The present invention is characterized in that it has an adsorption rotor carrying an adsorbent, is divided into at least an adsorption zone, a preheating zone, a regeneration zone, and a cooling zone with respect to the rotation direction of the adsorption rotor, passes a treatment gas through the adsorption zone and the cooling zone in the same flow direction, supplies the gas that has passed through the adsorption zone to a supply destination as a supply gas, passes the gas that has passed through the cooling zone through the preheating zone in the same flow direction as the treatment gas, mixes the gas that has passed through the preheating zone with outside air and passes it to a regeneration heater, passes it as a regeneration gas through the regeneration zone in the opposite direction to the flow direction of the treatment gas, desorbs the adsorption target adsorbed on the adsorption rotor, and releases the regeneration gas to the outside by a regeneration fan, and has a treatment fan that sends the treatment gas to the adsorption zone and the cooling zone of the adsorption rotor. Effect of the Invention

[0012] The gas treatment device of the present invention has the advantage that the adsorption rotor is preheated by the gas whose temperature has been increased by passing through the cooling zone, so that sufficient regeneration can be performed even with only a small amount of energy input into the regeneration zone, thereby contributing to energy savings.

[0013] With the configuration of the present invention, only two fans are required: a treatment fan that sends the gas flowing into the adsorption zone, and a regeneration fan that sends gas to pass the gas that has passed through the cooling zone through the preheating zone and then through the regeneration zone, thereby minimizing increases in costs.

[0014] Since the preheating zone and the cooling zone are provided on either side of the regeneration zone, which is the zone through which the gas with the highest concentration of the substance to be adsorbed passes, even if gas leaks from the regeneration zone, the leaked gas will not enter the adsorption zone. As a result, even if a leak does occur from the regeneration zone, the purity of the gas leaving the adsorption zone is maintained at a low level.

[0015] Furthermore, the adsorption rotor that has passed through the regeneration zone is at a high temperature, and if it enters the adsorption zone as is, it will hinder adsorption. Therefore, a cooling zone is provided after the regeneration zone and before the adsorption zone to purge the gas with a high temperature and high concentration of the adsorbent. Meanwhile, the end of the adsorption zone approaches adsorption saturation, so the concentration of the adsorbent gradually increases. Therefore, a preheating zone is provided after the adsorption zone and before the regeneration zone to cut off the gas with a high concentration of the adsorbent from the adsorption outlet gas and use it as regeneration gas.

[0016] Furthermore, if fans are installed to create positive pressure in the adsorption zone and negative pressure in the regeneration zone, even if a leak occurs in either zone, the gas leaving the regeneration zone will not enter the adsorption zone, and the gas concentration of the material to be adsorbed that has been reduced after leaving the adsorption zone will not increase due to a leak. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a flow diagram showing the gas flow in the gas treatment device according to the first embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing the division of the adsorption rotor into zones on the inlet side of the adsorption zone as viewed from the flow direction of the process gas. [Diagram 3] FIG. 3 is a diagram showing the division of the adsorption rotor into zones on the outlet side of the adsorption zone as viewed from the flow direction of the treated gas. [Figure 4] FIG. 4 is a flow diagram showing another example of the gas treatment device of the present invention. [Diagram 5] FIG. 5 is a flow diagram showing another example of the gas treatment device of the present invention. [Figure 6] FIG. 6 is a flow diagram showing another example of the gas treatment device of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] In the present invention, the adsorption rotor is divided into at least an adsorption zone, a preheating zone, a regeneration zone, and a cooling zone in the order of its rotation, the process gas is passed through the adsorption zone and the cooling zone in the same flow direction, the gas that has passed through the adsorption zone is supplied to the destination as feed gas, the gas that has passed through the cooling zone is passed through the preheating zone in the same flow direction as the process gas, the gas that has passed through the preheating zone is mixed with outside air and passed to the regeneration heater, and passed to the regeneration zone as regeneration gas in the opposite direction to the flow direction of the process gas, thereby achieving the objective of energy conservation with a minimum number of parts. EXAMPLES

[0019] Fig. 1 is a flow diagram showing the gas flow in the gas treatment device of the present invention. 1 is an adsorption rotor, which is already known in the art. This adsorption rotor 1 is divided into an adsorption zone 2, a cooling zone 3, a regeneration zone 4, and a preheating zone 5.

[0020] As shown in Fig. 2, the zones are divided into adsorption zone 2: cooling zone 3: regeneration zone 4: preheating zone 5=6:1:2:1, for example. As shown in Fig. 3, the adsorption rotor 1 rotates in the direction of the arrow.

[0021] The treatment fan 6 has an intake side which communicates with outside air OA and / or return air RA from the supply destination, and a discharge side which is connected to the adsorption zone 2 of the adsorption rotor 1 via an adsorption-side pipe C and a pipe D. The adsorption zone 2 is connected to a supply destination such as a dry room via a supply-side pipe E, whereby the supply gas SA is sent to the supply destination.

[0022] A cooling pipe F branches off from the adsorption side pipe C and communicates with the cooling zone 3. A return pipe G is connected to the outlet of the cooling zone 3, and the outlet of the return pipe G communicates with the inlet of the preheating zone 5.

[0023] A heater pipe H is connected to the outlet of the preheating zone 5. The heater pipe H is connected to an outside air mixing pipe I, which is connected to a regeneration heater 8. The regeneration side pipe J is connected to the regeneration zone 4. The outlet of the regeneration zone 4 is connected to the suction side of the regeneration fan 7 (pipe K), and the gas coming out from the discharge side of the regeneration fan 7 is released to the atmosphere as exhaust EA.

[0024] The first embodiment of the present invention is configured as described above and operates as follows. That is, when the processing gas passes through the adsorption zone 2 by the processing fan 6, the adsorption target material in the processing gas is adsorbed by the adsorption rotor 1 to become purified gas. This purified gas is supplied as a supply gas SA through the supply side pipe E to a supply destination such as a dry room.

[0025] A part of the treated gas is branched off and flows into the cooling pipe F. The cooling zone 3 is located immediately after the regeneration zone 4 and has a high temperature. Therefore, the cooling zone 3 is cooled by a part of the treated gas flowing into the cooling pipe F. The adsorption rotor 1 is cooled in the cooling zone 3 and moves to the adsorption zone 2, thereby increasing the adsorption effect.

[0026] Conversely, the temperature of the gas that has passed through the cooling zone 3 has increased, and this gas passes through return pipe G and enters the preheating zone 5 in the same flow direction as the treated gas. The preheating zone 5 is located immediately after the adsorption zone 2, and since no heat is supplied to the preheating zone other than the heat of adsorption, the temperature therein is not very high. Therefore, the adsorption rotor 1 is heated in the preheating zone 5 by the gas that has passed through the cooling zone 3, and is in a preheated state.

[0027] The gas that has passed through the preheating zone 5 is mixed with the outside air OA (including return air RA from the supply destination, a portion of the supply gas SA that has passed through the adsorption zone 2, and a portion of the regeneration gas that has left the regeneration zone 4) and is heated by the regeneration heater 8 as regeneration gas. The regeneration gas enters the regeneration zone 4 in the direction opposite to the flow of the treatment gas, and this portion is heated to desorb the adsorption targets adsorbed on the adsorption rotor 1. The temperature drops due to this desorption, and the gas, whose concentration has increased with the adsorption targets, is released into the atmosphere as exhaust EA by the regeneration fan 7.

[0028] In the above explanation, the gas that has entered the preheating zone 5 needs to be heated by the regenerative heater 8 to compensate for the thermal energy lost. Therefore, at first glance, it does not seem to save energy. However, in order to fully desorb the substances adsorbed on the adsorption rotor 1, it is necessary to sufficiently increase the temperature of the adsorption rotor 1.

[0029] When a solid is heated by the thermal energy of a hot gas, time is required for the heat transfer. In this respect, in the present invention, the adsorption rotor 1 first exchanges heat with the gas passing through the preheating zone 5, and then exchanges heat again with the gas passing through the regeneration zone 4. This lengthens the heating time of the adsorption rotor 1, i.e., the heat exchange time. In other words, in the case where there is no preheating zone 5, in order to raise the temperature of the adsorption rotor 1 to the same temperature as in the case where there is a preheating zone 5, the temperature of the gas leaving the regeneration heater 8 must be made higher.

[0030] In other words, without the preheating zone 5, the temperature of the gas entering the regeneration zone 4 must be increased, and the temperature of the gas leaving the regeneration zone 4 must also be increased. This increases the energy required for desorption and results in unnecessary energy release.

[0031] If the temperature of the gas leaving the regeneration zone 4 is high, it is necessary to use a regeneration fan 7 that is highly heat resistant, and furthermore, the lubricating oil for the bearings of the motor that drives the regeneration fan 7 will be consumed, resulting in high initial costs as well as high maintenance costs.

[0032] In the present invention, the gas that has passed through the preheating zone as the regeneration gas is mixed with the outside air OA, so that even if the optimal air volume required for regeneration differs from the optimal air volume required for cooling (preheating), the optimal air volume for regeneration can be adjusted. For example, the amount of gas passing through the cooling zone may be set to two-thirds or less of the amount of regeneration gas passing through the regeneration zone.

[0033] In the first place, compared to the known adsorption rotor that does not have a preheating zone and is composed only of an adsorption zone, a purge zone, and a regeneration zone, in the present invention, the adsorption rotor is preheated in the preheating zone before regeneration, so that regeneration can be performed with a smaller regeneration gas air volume. However, the optimal air volume required for regeneration and the optimal air volume required for cooling (preheating) are fundamentally different, and the outdoor air load is also different, especially in summer and winter, making it difficult to optimize the regeneration gas air volume. Therefore, it is significant that the gas that has passed through the preheating zone as regeneration gas can be mixed with the outdoor air OA to delicately adjust the cooling (preheating) air volume and the outdoor air OA introduction volume. Note that when the optimal cooling (preheating) air volume and the optimal regeneration air volume are equal, the outdoor air OA introduction volume may be set to zero.

[0034] As the adsorption rotor rotates, it moves to the preheating zone in a state where the temperature at the outlet side of the adsorption zone is increased by the heat of adsorption, but at the inlet side of the adsorption zone, the temperature remains low when it enters the preheating zone. Therefore, if the gas that has left the cooling zone, i.e., the gas whose temperature has increased due to the heat of adsorption when passing through the cooling zone and the heat from regeneration that remained in the cooling zone, is preheated in the preheating zone in the same flow direction as the processing gas, the preheating effect at the inlet side of the preheating zone (= outlet side of the regeneration zone) can be further enhanced. By supplying the gas whose temperature has increased by passing through the cooling zone to the preheating zone, the temperature of the gas used for preheating can also be increased. This increases the temperature of the adsorption rotor itself, which is expected to increase the amount of desorption in the regeneration zone, and also reduces the energy consumption of the regeneration heater.

[0035] In the cooling zone, the process gas is passed directly in the same flow direction as the process gas, so the adsorption rotor can be cooled with lower temperature gas than when gas that has passed through the adsorption zone is used in the cooling zone, further enhancing the cooling effect. By passing gas in the cooling zone in the same flow direction as the process gas (from the adsorption zone inlet side), the process gas hits the end face of the adsorption rotor, making the flow inside the rotor flutes turbulent, increasing the opportunities for contact between the adsorbent and the objects to be adsorbed, and the cooling effect of the adsorbent is expected to increase the amount of adsorption.

[0036] When the adsorption rotor rotates from the regeneration zone to the cooling zone, the temperature at the outlet side of the cooling zone (= inlet side of the regeneration zone) is high, and the temperature at the inlet side of the cooling zone (= outlet side of the regeneration zone) is low. By passing a low-temperature process gas through the cooling zone in the same flow direction as the process gas, the temperature of the entire adsorption rotor can be lowered while maintaining the temperature gradient across the width of the adsorption rotor. In the preheating zone, if gas is passed through in the same flow direction as the process gas, the adsorption rotor can be preheated while maintaining the temperature gradient across the width of the adsorption rotor.

[0037] By passing the gas in the same flow direction through the adsorption zone, preheating zone, and cooling zone, gas with a high concentration of the substance to be adsorbed that has left the regeneration zone does not enter the adsorption zone, further reducing the impact of leakage on the clean gas that has left the adsorption zone.

[0038] A portion of the treatment gas passed through the adsorption zone 2 is branched off and introduced into the cooling zone 3, but it is not necessary to install partition plates at the inlet sides of the adsorption zone 2 and the cooling zone 3 to separate the zones, which reduces costs.

[0039] Furthermore, by providing a sensible heat exchanger 9 and exchanging heat between the regeneration zone outlet exhaust gas EA and the outside air OA introduced into the regeneration zone, further energy savings can be achieved (Fig. 4). Note that the sensible heat exchange may be performed between the regeneration zone outlet exhaust gas EA and the gas that leaves the preheating zone before being mixed with the outside air OA (Fig. 5), or between the gas that leaves the preheating zone and flows to the regeneration fan after being mixed with the outside air OA (Fig. 6), or any combination of these may be used.

[0040] Table 1 shows an example of operating conditions for adsorbing and dehumidifying water in the air according to the first embodiment. [Table 1]

[0041] As described above, the adsorption rotor 1 is divided into at least the adsorption zone 2, preheating zone 5, regeneration zone 4, and cooling zone 3 in that order relative to its rotation direction, the treatment gas is passed through the adsorption zone 2 and the cooling zone 3 in the same flow direction, the gas that has passed through the adsorption zone 2 is supplied to the destination as feed gas, the gas that has passed through the cooling zone 3 is passed through the preheating zone 5 in the same flow direction as the treatment gas, the gas that has passed through the preheating zone 5 is mixed with outside air and passed to the regeneration heater 8, and passed to the regeneration zone 4 as regeneration gas in the opposite direction to the flow direction of the treatment gas. Therefore, even if the temperature of the gas that has passed through the regeneration zone 4 is lowered, sufficient removal performance can be exhibited, and the energy saving effect is high. [Industrial Applicability]

[0042] In a gas treatment device using an adsorption rotor, it is possible to reduce energy consumption without impairing the ability to remove substances to be adsorbed. [Explanation of symbols]

[0043] 1 Adsorption rotor 2 Adsorption Zone 3 Cooling Zone 4. Play Zone 5 Preheat Zone 6 Processing Fan 7. Play Fan 8 Regenerative Heater 9. Sensible heat exchanger

Claims

1. A gas treatment device comprising an adsorption rotor carrying an adsorbent that adsorbs moisture, the device being divided into at least an adsorption zone, a preheating zone, a regeneration zone, and a cooling zone relative to the direction of rotation of the adsorption rotor, air as a process gas being passed through the adsorption zone and the cooling zone in the same flow direction, gas that has passed through the adsorption zone being supplied as a supply gas to a destination, gas that has passed through the cooling zone being passed through the preheating zone in the same flow direction as the process gas, gas that has passed through the preheating zone being mixed with outside air and passed to a regeneration heater, and gas being passed through the regeneration zone in the opposite direction to the process gas as a regeneration gas, and moisture as an object to be adsorbed that has been adsorbed by the adsorption rotor being desorbed, thereby cooling the adsorption rotor in the cooling zone and preheating it in the preheating zone while maintaining a temperature gradient in the width direction of the adsorption rotor, in which the temperature on the outlet side of the cooling zone is high and the temperature on the inlet side of the cooling zone is low, a regeneration fan for discharging the gas that has passed through the regeneration zone to the outside, and a treatment fan for sending the treatment gas to the adsorption zone and the cooling zone, A gas treatment device characterized in that the treatment fan is installed on the inlet side of the adsorption zone so that the adsorption zone is under positive pressure, and the regeneration fan is installed on the outlet side of the regeneration zone so that the regeneration zone is under negative pressure.

2. 2. The gas treatment apparatus according to claim 1, wherein the amount of gas passing through said cooling zone is set to 2 / 3 or less of the amount of gas passing through said regeneration zone.

3. 3. The gas treatment device according to claim 1, further comprising a sensible heat exchanger for exchanging heat between the exhaust gas at the outlet of the regeneration zone and outside air to be introduced into the regeneration zone, and / or the gas leaving the preheating zone before being mixed with the outside air, and / or the gas leaving the preheating zone and mixed with the outside air and flowing to the regeneration fan.

Images