JPS6335293B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for regenerating an adsorbent in a thermal regeneration type air drying apparatus using a plurality of adsorbent packed columns, and more specifically, the present invention relates to a method for regenerating an adsorbent in a thermal regeneration type air drying apparatus using a plurality of adsorbent packed columns, and more specifically, for the thermal regeneration of the air drying apparatus, high temperature The air after heat regeneration is directly used as air for heat regeneration to perform heat regeneration, and the air after heat regeneration is cooled and dehumidified to become product air. In an air drying device that uses part of the dried air as cooling air for cooling, a necessary amount of adsorbent and heat capacity of sand, steel balls, glass beads, etc. are placed in the adsorbent packing tower. A heat storage material laminated adsorbent packed tower is used, which is filled with a large heat storage material divided into two layers.
In the cooling process, the air drying device obtains highly dry air by transferring the sensible heat stored in the heat storage material and the sensible heat possessed by the adsorbent during heating regeneration and removing moisture remaining in the adsorbent. This invention relates to a method for regenerating an adsorbent.

FIG. 1 is a system diagram of a conventional heat regeneration type air drying apparatus. This will be explained below with reference to the same figure. While one packed tower performs dehumidification for 8 hours, the other packed tower performs heating regeneration using heated air from a blower for 3 hours, and cooling after heating regeneration is performed for 8-3 = 5 hours.
After a certain period of time, both packed towers are switched and operated continuously.

Atmospheric air is sucked from the feed air source blower 1 and the compressed high-temperature air passes through piping 2, three-way valve 3, piping 4, four-way valve 5, and piping 6, enters packed tower 7A, and is adsorbed by adsorbent 8A. The high-temperature air after the separation passes through the piping 9 and the four-way valve 10 and flows to the piping 13, but the same amount of air as that required for cooling, which will be described later, is released from the piping 11 and the solenoid valve 12 into the atmosphere. released to. (At this time, the solenoid valve 33 is closed.) This is to keep the amount of product air constant during heating and cooling. However, it goes without saying that the solenoid valve 12 can be omitted if there is no problem even if the product air amount varies between heating and cooling. The heated and regenerated air, which should become product air, passes through piping 13, check valve 14, and piping 15, and is cooled by a primary cooler 16 that uses cooling water 17 (cooling tower water, etc.). Drain pit 2
It is discharged at 4. The air further passes through piping 18 and is sufficiently cooled by a secondary cooler 19. When the chiller unit 20 is used for cooling, the cold water 21
When the refrigerator 20 is used, the refrigerant 21 is supplied to the secondary cooler 19 and the air is cooled to 2 to 15 DEG C., and the condensed water produced by the cooling is discharged from the drain pipe 23 to the drain pit 24. Sufficiently cooled and dehumidified air passes through piping 25, four-way valve 10, and piping 26, enters one packed tower 7B, and enters adsorbent 8B.
The moisture is dehumidified and becomes dry air by piping 27,
It passes through the four-way valve 5 and piping 28 and becomes product air. The above is the heating regeneration process of the packed tower 7A. Next, the process moves to the cooling process of the packed tower 7A. The three-way valve 3 is switched by a preset timer, and the solenoid valve 12 is switched.
is closed, and at the same time, the solenoid valve 33 is opened.

The high-temperature air sucked and compressed by the blower 1 passes through the piping 2, the three-way valve 3, and the piping 15, and passes through the primary cooler 16, piping 18, and the secondary cooler 19 in the same manner as above, and the sufficiently cooled and dehumidified air passes through the piping. 25,
The air enters the packed tower 7B via the four-way valve 10 and piping 26, and is dehumidified by the adsorbent 8B, passes through the piping 27, four-way valve 5, and piping 28, and becomes product air. On the other hand, the air necessary for cooling the packed tower 7A is supplied from the pipe 28 to the pipe 2.
9, the amount necessary for cooling (1/10 to 1/5 of the product air) is branched, passes through a check valve 30, a pipe 31, and enters a packed tower 7A via a pipe 4, a four-way valve 5, and a pipe 6. The adsorbent 8A and the packed tower 7A after being heated and regenerated are cooled, and at the same time, the equilibrium adsorbed water remaining in the adsorbent 8A is removed using the sensible heat of the adsorbent 8A. The heated air after cooling is transferred to piping 9, four-way valve 10, and piping 3.
2. It passes through the solenoid valve 33 and is released into the atmosphere.

The above is the cooling process of the packed tower 7A, and when the cooling is completed, the entire process of separation and regeneration is completed, and the packed tower is switched to proceed to the dehumidification process. Each packed tower is switched every 8 hours and repeats the dehumidification process, heating regeneration and cooling process to deliver dry product air.

According to the conventional method described above, by using the heated air discharged from the blower for heating regeneration of the adsorbent-packed tower, the air for heating regeneration carried out in general heat regeneration type air drying equipment can be heated to a high temperature. It is possible to omit the need for a heater for heating, reducing the facility cost and operating cost to zero; In conventional systems in which heat is transferred and removed, the temperature of the heated air discharged from the blower is important. The temperature of the air discharged from the blower varies depending on the volumetric efficiency of the blower, but generally it is 100℃ to 130℃ in the case of high pressure.
It is. Therefore, the regeneration temperature in the conventional method is
The temperature will be 100-130℃. This is lower than the general heat regeneration temperature (200°C to 300°C), so there is a lot of moisture remaining in the adsorbent at the end of heating, and even more moisture remains in the adsorbent, especially in a high humidity atmosphere such as in the summer. Under these conditions, the sensible heat of the adsorbent and adsorption tower is insufficient to remove the residual moisture during cooling, resulting in insufficient regeneration and difficulty in obtaining highly dehumidified product air.

The object of the present invention is to improve such drawbacks and to make it possible to obtain stable dry air with a high dew point even under any environment such as summer. That is, in the present invention, the adsorption tower is filled with a required amount of adsorbent and a heat storage material having a large heat capacity per volume, such as sand, glass beads, and steel balls, and is stacked in two layers, and regarding the arrangement of the heat storage materials. By packing and stacking the adsorbent at a certain height on the adsorbent surface layer on the dehumidified air outlet side of the packed tower, that is, on the regenerated air inlet side, the residual moisture during cooling is removed by the sensible heat stored by the heat storage material during regeneration. Compensates for the lack of heat generated during cooling, reduces the amount of moisture remaining in the adsorbent at the end of cooling compared to conventional products, and reduces the amount of moisture remaining in the adsorbent, especially in the surface layer of the adsorbent on the outlet side of the dehumidified air of the adsorption tower. The purpose is to improve the dew point of product air obtained during dehumidification by separating the air, compared to conventional products, and to always obtain product air with a stable high dew point.

The distribution of residual moisture and the dew point of dehumidified air during heating and regeneration in the adsorption tower of the present invention as described above and the dew point of the dehumidified air are qualitatively illustrated in FIG. As shown in the figure, in the conventional case [2], there is a small amount of residual moisture in the adsorbent near the product air outlet even after cooling is finished, but in the case of the present invention [1], which uses a heat storage material, the moisture is completely removed. Therefore, it can be seen that the dew point of the product air during adsorption dehumidification is lower than that in the conventional method, and highly dried product air can be obtained.

An embodiment of the present invention is shown in FIG. 3 below. In Figure 3, while one packed tower performs dehumidification for 8 hours, the other packed tower performs separation regeneration using heated air from a blower for 3 hours, and cooling after heating regeneration is performed for 8-3 hours.
= 5 hours, and after 8 hours, both towers are switched and operated continuously.

To explain in more detail, atmospheric air is sucked and pressurized from a raw material air source blower, and the heated raw material air is passed through piping 2,
It enters the adsorption tower 7A through the 3-way valve 3, piping 4, 4-way valve 5, and piping 6, heats the heat storage material 8A, and further adsorbent 9.
The moisture adsorbed in A is removed, and the air after the separation passes through piping 10 and four-way valve 11, where the same amount of cooling air as in the cooling process described later is transferred to piping 1.
2 solenoid valve 13 to the atmosphere. (At this time, the solenoid valve 34 is closed.) This is to keep the amount of product air constant during heating and cooling, and by doing so, the amount of moisture absorbed during the dehumidification process is reduced. This has the effect of making the packed tower smaller. However, if there is no problem even if the amount of product air fluctuates during heating and cooling, it goes without saying that the air after heating and regeneration will be all product air, and the solenoid valve 13 will be eliminated.

The heated and regenerated air, which should become product air, passes through the pipe 14, passes through the check valve 15, and then passes through the pipe 16.
The water is introduced into a primary cooler 17 using cooling water 18 and cooled. Condensed water generated by cooling is discharged from the drain pipe 23 to the drain pit 25.
The cooled air further passes through a pipe 19 and is sufficiently cooled by a secondary cooler 20, and the condensed water generated by the cooling is discharged from a drain pipe 24 to a drain pit 25. Sufficiently cooled and dehumidified air is supplied to pipes 26 and 4.
The air passes through the one-way valve 11 and the piping 27, enters the packed tower 7B, and is dehumidified by the adsorbent 9B, becoming dry air, passing through the piping 28, the four-way valve 5, and the piping 29, and becomes product air. This step is the heating regeneration step of the packed tower 7A. Next, the process moves to the cooling process of the packed tower 7A. For cooling, a part of the dry product air obtained in the dehumidification process of the packed tower 7B is branched and used as cooling air.

3-way valve 3 by pre-set timer
is switched, the solenoid valve 13 is closed, and at the same time the solenoid valve 34 is opened.

The high-temperature air sucked and compressed by the blower 1 passes through the piping 2, the three-way valve 3, and the piping 16, and is introduced into the primary cooler 17 and cooled in the same manner as described above. Condensed water generated by cooling is drained from pipe 23 to drain bit 2.
It is discharged at 5. The cooled air is introduced into the secondary cooler 20 through the piping 19 and is sufficiently cooled, and the condensed water generated by the cooling is passed through the piping 24 into the drain pit 2.
It is discharged at 5. The sufficiently cooled and dehumidified air then passes through piping 26, four-way valve 11, and piping 27, enters packed tower 7B, and is dehumidified by adsorbent 9B, becoming dry air through piping 28, four-way valve 5, and piping 29. The product becomes air. On the other hand, the air necessary for cooling the packed tower 7A is branched from the pipe 29 to the pipe 30 in an amount necessary for cooling, and the check valve 31, the pipe 32, and the pipes 4, 4.
The heat storage agent 8 enters the packed tower 7A through the direction valve 5 and piping 6.
A and the adsorbent 9A, and the sensible heat of the packed tower 7A is transferred to remove the moisture remaining in the adsorbent 9A, and cooling is performed. In particular, the sensible heat of the heat storage material 8A is used to transfer the sensible heat of the packed tower 7A to the heat storage material layer of the adsorbent 9A. Completely removes residual moisture in the adsorbent on the surface layer that is in contact with it. After cooling, the air is transferred to piping 10, four-way valve 11, and piping 3.
3. It is released into the atmosphere from the solenoid valve 34. The above is the cooling process of the packed tower 7A. When the cooling process is completed, all processes of heating regeneration and cooling process of the packed tower 7A are completed, and at the same time, both packed towers are switched and the same operation as above is performed, and this is switched every 8 hours to continuously send out dry air. It is.

The effects of the embodiments of the present invention will be explained below.
A packed tower with an inner diameter of 40 cm was filled with silica gel as an adsorbent to a height of 100 cm (approximately 100 kg), and then gravel (4 to 6 φ) was selected as a heat storage material and packed and stacked to a height of 20 cm (approximately 40 kg). The total length of the packed bed is 120cm. Using the above packed tower, air at 33°C, 75% R・H (moisture content 28g/Nm ³ ) was supplied as regenerated air using a blower at 1.0kg/
The mixture was pressurized to cm ² , heated to 110° C., heated and regenerated for 3 hours at a flow rate of 209 Nm ³ /h, and cooled after heating and regenerated using dehumidified dry air at 19 Nm ³ /h for 5 hours.

Next, we move on to the dehumidification process, where the raw air is dehumidified at a temperature of 10°C, a pressure of 0.9 kg/cm ² and a flow rate of 190 Nm ³ /h (moisture content: 4.9 g/Nm ³ ), and the dew point of the resulting product air is -70°C.
(moisture content: 0.002 g/Nm ³ ), and the breakthrough time was 12.5 hours.

As shown in the examples above, according to the present invention that uses a heat storage material, dry product air at an exposure temperature of -70°C can be obtained by regenerating only the air discharged from the blower even under high temperature conditions in summer due to the release effect due to heat storage. be able to.

As described above, according to the present invention, it is possible to sufficiently remove residual moisture during cooling during the dehumidification and regeneration process of the adsorbent, and to obtain dry air with a stable high dew point.

[Brief explanation of the drawing]

Fig. 1 is an air system diagram of a conventional heat regeneration type air drying device, Fig. 2 is a characteristic diagram showing the distribution of residual moisture in the adsorption tower and the dew point of dehumidified product air in the conventional one and the present invention. The figure is an air system diagram in an embodiment of the present invention. 1...Blower, 2...Piping, 3...3-way valve, 4
... Piping, 5 ... 4-way valve, 7 ... Adsorption tower, 8 ...
Heat storage material, 9... Adsorbent, 13... Solenoid valve, 17...
...Primary cooler, 18...Cooling water, 20...Secondary cooler.

Claims (1)

[Claims] 1. High-temperature, high-pressure air generated from a high-pressure air source is guided through a cooler to the entrance of a packed tower that is filled with adsorbent and has an air-permeable heat storage material layer that hardly absorbs moisture at the outlet of the inside. , adsorbs moisture in the air through this interior,
For a packed tower that generates dry air and requires regeneration after adsorption, the pipe line from the high-pressure air source is switched to the outlet thereof, and high-temperature, high-pressure air is introduced.
Supply from this outlet for a predetermined heating time,
heating the heat storage material tank and the adsorbent at the outlet, and passing the heated air discharged from the entrance of the regeneration-side packed tower through the cooler and then supplying it as raw air to the entrance of the packed tower during adsorption; Furthermore, after the heating time has elapsed, the pipe line from the high-pressure air source is switched to supply high-temperature, high-pressure air to the cooler, and a portion of the dry air discharged from the outlet of the packed tower during pre-air adsorption is transferred to the The cooled air is guided to the outlet of the heated packed tower and supplied from this outlet during a predetermined cooling period to cool the adsorbent while moving the sensible heat of the heat storage material tank to the inlet side. This is a method for regenerating the adsorbent in an air drying device that exhausts the air to the outside.