KR100976553B1 - Method for regenerating adsorbent by heating of absorption type air drying system - Google Patents

Abstract

The present invention relates to an adsorption dehumidification system, and more particularly, heating of an adsorption dehumidification system using compressed heat, which can greatly reduce energy consumption by efficiently controlling the heating of regeneration air necessary for the regeneration process of the adsorption dehumidification system. It relates to a regeneration method.

The heating and regenerating method of the adsorption type dehumidification system using the heat of compression according to the present invention includes a first step of circulating the regeneration air to one of the first and second adsorption towers by the regeneration direction switching valve; A second step of selectively driving the heater according to a temperature state in the adsorption tower; And a third step of allowing the regeneration air to pass through the adsorption tower to be heated and regenerated.

Adsorption, dehumidification, heating, regeneration, heater

Description

Heat recovery method of adsorption type dehumidification system using compressed heat {METHOD FOR REGENERATING ADSORBENT BY HEATING OF ABSORPTION TYPE AIR DRYING SYSTEM}

The present invention relates to an adsorption dehumidification system, and more particularly, heating of an adsorption dehumidification system using compressed heat, which can greatly reduce energy consumption by efficiently controlling the heating of regeneration air necessary for the regeneration process of the adsorption dehumidification system. It relates to a regeneration method.

As is well known, the dehumidification system for removing moisture contained in the air is widely used in various automated equipments requiring dry air, semiconductor manufacturing processes, and production lines of chemical processes that cause chemical reactions in contact with moisture.

The dehumidification system is a refrigeration dehumidification system that lowers the temperature of the compressed air by using a refrigeration compressor and then dehumidifies by condensing moisture contained in the compressed air, and air contained in humid air by using an adsorbent (or a dehumidifying agent or a desiccant). It is divided into adsorption type dehumidification system which adsorbs and dehumidifies.

Of these, referring to the general configuration and function of the adsorption-type dehumidification system related to the present invention as follows.

The above-mentioned adsorption type dehumidification system includes a pair of adsorption towers containing an adsorbent, a direction change valve for changing the direction of compressed air so that dehumidification and regeneration processes are alternately performed in the pair of adsorption towers, and operation of the direction change valve. It consists of a control unit including a solenoid valve and a timer to control the.

The adsorption dehumidification system is classified into a heat adsorption dehumidification system for regenerating the adsorbent using a predetermined heat source and a non-heat adsorption dehumidification system for regenerating the adsorbent using only regeneration air according to the regeneration method of the adsorbent. In particular, the non-heat adsorption dehumidification system requires a heater for heating the temperature of the regeneration air to a temperature suitable for regeneration (approximately 170 ~ 200 ℃), accordingly, by continuously operating the heater during the regeneration process The temperature of the regeneration air has been heated to a temperature suitable for regeneration.

However, the conventional adsorption type dehumidification system using the heat of compression has a disadvantage in that the energy is wasted as the heater is continuously driven during the regeneration process.

The present invention has been made in view of the above, the adsorption dehumidification system using the heat of compression that can significantly reduce energy consumption by sensing the temperature in the adsorption tower during the regeneration process of the adsorption dehumidification system to properly control the driving of the heater. The purpose of the present invention is to provide a heating and regeneration method.

In order to achieve the above object, a preferred embodiment of the present invention includes a compressor for sucking and compressing external humid air, first and second adsorption towers, and installed under the first and second adsorption towers for dehumidifying air and regeneration. The first direction switching valve for switching the conveying direction of the air for air, The second direction switching valve is installed on top of the first and second adsorption tower to switch the conveying direction of the dehumidifying air and the regeneration air, The first and second Adsorption dehumidification comprising a regeneration directional valve connected to the two direction switching valve for circulating the regeneration air to the first and second adsorption tower, a heater installed on the pipe in communication with the upper portion of the first and second adsorption tower, In the system,

A first step of circulating the regeneration air to one of the first and second adsorption towers by the regeneration direction switching valve;

A second step of selectively driving the heater according to a temperature state in the adsorption tower; And

It is to provide a heat regeneration method comprising a third step of passing the regeneration air to the inside of the adsorption column to heat regeneration.

The second step,

Step 2-1 of detecting the temperature in the adsorption tower in which the regeneration process is performed among the first and second adsorption towers;

Step 2-2 of determining whether the sensed temperature corresponds to the compression heat temperature of the compressor; And

When the temperature in the adsorption tower corresponds to the compression heat temperature of the compressor, the second step is performed by heating the regeneration air to the regeneration temperature by driving the heater.

In the step 2-1, the lower temperature in the adsorption tower is detected by a temperature sensor.

In step 2-2, the compression heat temperature of the compressor is 90 ~ 150 ℃.

In step 2-3, the regeneration temperature is 170 ~ 250 ℃.

The present invention as described above has the advantage that the energy consumption can be significantly reduced by driving the heater only when the temperature in the adsorption tower in which the heat regeneration process is performed corresponds to the compression heat temperature of the compressor.

In addition, the present invention has the advantage that the heating and regeneration efficiency can be significantly improved by precisely and accurately controlling the temperature of the regeneration air.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2 show an adsorptive dehumidification system of an exemplary form according to the present invention.

The adsorption type dehumidification system according to FIG. 1 includes first and second adsorption towers 112 and 114 for performing alternate dehumidification and regeneration, a compressor 120 for compressing external humid air, and one of the adsorption towers 112 and 114. The first and second directional valves 260 for switching the dehumidifying air and the regeneration air to the conveying direction to the regeneration directional valve 190, the first and second adsorption towers 112, 114 for circulating the regeneration air. , 270, and a heater 210 installed in the regeneration line of the redirection valve 190 for regeneration.

The first and second adsorption towers 112 and 114 are formed in a closed cylindrical shape having a predetermined length, and an adsorbent is filled therein, and upper and lower inlets and outlets used to replace the adsorbent are respectively. Is installed. Adsorbents filled in the adsorption towers 112 and 114 include activated alumina, silica gel, alumina silica gel, and molecular sieves.

The compressor 120 is for compressing the wet air introduced from the outside to a predetermined pressure (about 7.0 kg / cm 2), and a conventional screw compressor or turbo compressor is used. For example, a screw compressor produces about 150 [deg.] C. of compression heat during compression, and a turbo compressor produces about 120 [deg.] C. during the compression. That is, the compressor 120 preheats the wet air with a compression heat of about 90 to 150 ° C., and the compressed wet air has a temperature of about 90 to 150 ° C.

The first branch point 130 is located at the discharge port of the compressor 120, and the first branch point 130 is a point where the compressed humid air is branched into the dehumidifying air and the regeneration air, and the branched regeneration air is a total. It is preferably about 30-40% of air.

The first cooler 140 is installed on the pipe in which the dehumidifying air is transferred among the pipes branched from the first branch point 130, and the first cooler 140 sets the dehumidifying air at high temperature and high pressure to about 40 ° C. or lower. Cool.

The first water separator 150 is installed at the discharge port of the first cooler 140, and the first water separator 150 separates moisture from the humid air cooled by the first cooler 140.

The pretreatment filter 160 is installed at the discharge port of the first water separator 150, and the pretreatment filter 160 once again removes foreign substances (water or oil, dust, etc.) that were not removed from the first water separator 150. do.

The second branch point 170 is located at the discharge port side of the pretreatment filter 160, and the second branch point 170 is a point for separating the dehumidifying air and the regeneration air again, wherein the renewed air is separated from the pretreatment filter 160. ) Is preferably about 30 to 40% of the wet air from which foreign matter is removed. At this time, the ratio of the dehumidifying air and the regeneration air branched from the second branch point 170 is adjustable by the flow control valve 180.

The flow control valve 180 is installed on one side of the second branch point 170, that is, the pipe through which the dehumidifying air is transferred, and adjusts the ratio of the dehumidifying air and the regeneration air branched from the second branch point 170. . That is, the ratio of the dehumidification air and the regeneration air is adjusted so that the amount of regeneration air used at the time of regenerating the adsorbent is always kept constant. When the inlet pressure of the flow control valve 180 increases, the amount of regeneration air decreases, and when the inlet pressure decreases, the amount of regeneration air increases.

The regeneration direction switching valve 190 is for regenerating the adsorbent by circulating the regeneration air branched from the first branch point 130 and the regeneration air branched from the second branch point 170, the regeneration line of the regeneration air First to fourth on / off valves 192, 194, 196, and 198 provided on the upper surface, and controlling the opening and closing of the adsorbents to regenerate heat or cool.

The heater 210 installed on the regeneration line of regeneration air is for heating the regeneration air transferred to the first or second adsorption tower 112 or 114, and a conventional electric heater is used. At this time, the regeneration air transferred to the heater 210 is a regeneration air of a high temperature (about 90 ~ 150 ℃) branched from the first branch point 130, up to a regeneration temperature (approximately 170 ~ 200 ℃) suitable for regeneration Not much energy is consumed for heating. In other words, it is possible to heat the air for regeneration to the required temperature even with little energy, so the energy consumption is low. Thus, the heater 210 used in the present invention may have a small capacity and a short running time of the heater.

Here, the temperature of the regeneration air heated by the heater 210 depends on the type of adsorbent. For example, regeneration air of about 185 ° C to 205 ° C is required to regenerate activated alumina by heating, and regeneration air of about 120 ° C to 150 ° C is required to heat regenerate silica gel. In order to do so, regeneration air of about 210 to 230 ° C is required.

The second cooler 220 and the second water separator 230 are installed on the regeneration line of the redirection valve 190 for regeneration, and the second cooler 220 is configured to connect the first or second adsorption tower 112 or 114 to the regeneration valve. It is for cooling the regenerated air that has passed, and is cooled to a temperature of about 40 ° C. or less as in the first cooler 140.

The second water separator 230 is installed at the discharge port side of the second cooler 220, and the second water separator 230 separates the water contained in the regeneration air cooled by the second cooler 220.

In addition, an aeration point 250 is positioned at a portion where the downstream of the flow control valve 180 and the downstream of the second water separator 230 intersect, and the aeration point 250 is a dehumidification that has passed through the flow control valve 180. The air and the regeneration air passing through the second water separator 230 is a point to join.

The first directional valve 260 is connected to the regeneration line of the regeneration air, the lower portion of the first and second adsorption tower (112, 114) flows into the first and second adsorption tower (112, 114) or the first and second 2 The transfer direction of the dehumidifying and regenerating air discharged from the adsorption towers 112 and 114 is switched.

The second diverter valve 270 is connected to the upper part of the first and second adsorption towers 112 and 114, the regeneration line of the regeneration air, and flows into the first and second adsorption towers 112 and 114, or the first and second 2 The transfer direction of the dehumidifying and regenerating air discharged from the adsorption towers 112 and 114 is switched.

The first and second directional valves (260, 270) is composed of four on-off valves (262, 264, 266, 268; 272, 274, 276, 278), respectively, when combining the opening and closing of the dehumidifying air And the first and second adsorption towers 112 and 114 alternately mutually dehumidify and regenerate by selectively intermitting the transfer of the regeneration air.

The dry air dehumidified by the first and second directional valves 260 and 270 is removed once more by the aftertreatment filter 280 and then discharged to various places of use.

On the other hand, the adsorption type dehumidification system according to Figure 2 has a discharge means 240 for discharging the regeneration air discharged from the second separator 230 to the outside on the discharge port side of the second separator (230). The discharge means 240 includes a pair of open / close valves 242 and 244 having different discharge amounts, and a silencer 246 coupled to the discharge port side of the open / close valve, and the pair of open / close valves 242 and 244. Are connected in parallel.

The discharge means 240 configured as described above is to select and operate the adsorption type dehumidification system in a purge method or a non-purge method according to the amount of dry air to be produced. That is, when the amount of air (dry air) to be produced is small, the discharge means 240 is opened to discharge the regeneration air discharged from the second separator 230 to the outside so as to be operated in a purge manner. If the amount of air (dry air) is large, the discharge means 240 is closed so that the regeneration air discharged from the second separator 230 is joined with the dehumidifying air at the aeration point 250 and the non-purging method. To be operated. Therefore, good energy efficiency can always be obtained regardless of the amount of air (dry air) to be produced. In addition, it is a matter of course that the amount of compressed air compressed by the compressor can be applied to other early or mid-stage operation. In particular, when a plurality of open / close valves 242 and 244 having different discharge amounts are connected in parallel, the amount of regeneration air discharged to the outside can be finely adjusted at a time when the operation method (purge method or non-purge method) is changed. The fall of energy efficiency can be prevented.

And, the adsorption type dehumidification system according to Figures 1 and 2 has a dew point control device (290). Dew point controller 290 is installed on the circulation line of the regeneration air extending to the lower side of the first and second adsorption tower (112, 114) detects the temperature of the recirculation air circulating and uses the shut-off valve described below A temperature controller 292 for regulating the temperature, a shutoff valve 294 for circulating and blocking regeneration air, and an upper portion of the first and second adsorption towers 112 and 114 by being opened and closed by the temperature controller 292. It includes a dew point measuring device 296 installed on one side of the pipe extending to the side.

The dehumidification and regeneration (heating and cooling) process of the adsorption type dehumidification system according to FIGS. 1 and 2 will be described. In this case, it is assumed that dehumidification and regeneration are simultaneously performed in each adsorption tower 112 and 114, and dehumidification is performed in the second adsorption tower 114 in the first adsorption tower 112.

First, the dehumidification process is as follows.

After the humid air introduced from the outside is compressed by the compressor 120 to a high temperature (about 90 ~ 150 ℃) and high pressure (about 7.0kg / ㎠), through the first branch point 130, dehumidification air and regeneration air And dehumidifying air in the air separated from the first branch point 130, passes through the first cooler 140, the pretreatment filter 160, the first water separator 150, and then the second branch point 170. Through the dehumidification and regeneration air.

The dehumidifying air branched from the second branch point 170 is transferred to the first direction switching valve 260 via the flow control valve 180, and the first and fourth switching valves of the first direction switching valve 260 ( The dehumidifying air is introduced into the first adsorption tower 112 by opening the 262 and 268 and closing the second and third on / off valves 264 and 266.

The dehumidifying air introduced into the first adsorption tower 112 is contacted with the adsorbent therein to become dry air from which water is completely removed, and then discharged to various places of use. In this case, the first and fourth on-off valves 272 and 278 of the second direction switching valve 270 are closed, and the second and third on-off valves 274 and 276 are opened to discharge the dehumidifying air to the outside. To help.

And, look at the heating regeneration process as follows.

Regeneration air (about 30 to 40% of the amount of air discharged from the compressor) separated at the first branch point 130 passes through the heater 210 installed on the regeneration line of the redirection valve 190 for regeneration. After heating to ℃, it is introduced into the second adsorption tower 114 through the first opening and closing valve 192 of the regeneration direction switching valve 190. At this time, as in the dehumidification process, the first and fourth on-off valves 272 and 278 of the second direction switching valve 270 are closed, and the second and third on-off valves 274 and 276 are opened, and for regeneration. The third and fourth on-off valves 196 and 198 of the direction change valve 190 are closed.

The regeneration air introduced into the second adsorption tower 114 desorbs moisture of the adsorbent charged therein, and the fourth opening / closing valve 268 of the first direction switching valve 260 and the direction switching valve 190 for regeneration. It is transferred to the second cooler 220 through the second opening and closing valve 194 of the, and after cooling to about 40 ℃ through the second cooler 220, to remove foreign substances including water in the second water separator (230). do.

Regeneration air from which foreign matter, including moisture, is removed through the second water separator 230 is discharged to the outside through the discharge means 240 when operated in the adsorption type dehumidification system of FIG. If so, the air may be joined to the dehumidifying air through the aeration point 250 and introduced into the first adsorption tower 112.

The cooling and regeneration process is as follows.

The regeneration air branched from the first branch point 170 (about 30 to 40% of the dehumidifying air from which the foreign matter is removed from the pretreatment filter 160) is the third opening / closing valve 196 of the redirection valve 190 for regeneration. And it is introduced into the second adsorption tower 114 through the fourth opening and closing valve 268 of the first direction switching valve 260. At this time, as in the dehumidification process, the first and fourth on-off valves 262 and 268 of the first direction switching valve 260 are opened, and the second and third on-off valves 264 and 266 are closed, and for regeneration. The first and second on-off valves 192 and 194 of the direction switching valve 190 are closed.

The regeneration air introduced into the second adsorption tower 114 desorbs the moisture of the adsorbent charged therein, and the second opening / closing valve 278 of the second direction switching valve 270 and the direction switching valve 190 for regeneration. It is transferred to the second cooler 220 through the fourth opening and closing valve (198) of the, and after cooling to about 40 ℃ through the second cooler 220, foreign matter containing water in the second water separator (230). Remove

In addition, in the adsorption dehumidification system of FIG. 2, the regeneration air in which foreign matter including moisture is removed through the second water separator 230 is discharged to the outside through the discharge means 240 when the adsorption dehumidification system is operated in a purge manner. In case of being operated in a non-purging manner, the air may be joined to the dehumidifying air through the aeration point 250 and introduced into the first adsorption tower 112.

On the other hand, Figure 3 shows a heating regeneration control method of the adsorption type dehumidification system according to the present invention.

As shown, the heating regeneration control method of the adsorption-type dehumidification system according to the present invention, the first step (S1) circulating the regeneration air to any one of the adsorption tower (112, 114), the temperature in the adsorption tower (112, 114) A second step S2 of selectively driving the heater 210 according to a state, and a third step S3 of heating and regenerating the regenerated air through the adsorption towers 112 and 114.

The wet air compressed by the compressor 120 is heated and discharged by about 90 to 150 ° C. by the heat of compression of the compressor 120, and the heated wet air is separated into regeneration air at the first branch point 130. Air is circulated to the adsorption tower of any one of the first and second adsorption towers 112 and 114 through the redirection valve 190 for regeneration (S1). At this time, the heater 210 heats the regeneration air heated to about 90 ~ 150 ℃ to a regeneration temperature of about 170 ~ 250 ℃, the regeneration air having a suitable regeneration temperature in the upper portion of the adsorption tower (112, 114) By passing downward, the inside of each adsorption tower 112 and 114 can be appropriately recycled.

On the other hand, in the heating regeneration control method of the present invention, if the heater 210 is continuously driven during the heating regeneration process, waste of energy due to the continuous driving of the heater 210 is increased, resulting in an increase in the overall operating cost.

Accordingly, according to the present invention, after the temperature state in the adsorption towers 112 and 114 is properly sensed (S2-1), the temperature in the sensed adsorption towers 112 and 114 becomes the compression heat temperature of the compressor 120 (approximately 90 to 90 °). 150 ° C.) (S2-2), the heater 210 is selectively driven to heat the regeneration air to a regeneration temperature of approximately 170 to 250 ° C. (S2-3).

In particular, it may be desirable to more accurately control the regeneration temperature of the regeneration air by sensing the lower temperature in the adsorption tower (112, 114) by the temperature sensor.

In this way, the heater 210 is selectively driven according to the temperature in the adsorption towers 112 and 114, thereby allowing regeneration air having an appropriate regeneration temperature (about 170 to 250 ° C) to pass through the adsorption towers 112 and 114. The heating regeneration process is performed (S3).

1 is a view showing an example of an adsorption type dehumidification system.

2 is a view showing another example of a dehumidification system at the time of adsorption.

Figure 3 is a flow chart illustrating a heating and regenerating method of the adsorption type dehumidification system according to an embodiment of the present invention.

4 is a flowchart illustrating a heater driving step in the heating regeneration method according to the present invention.

Brief description of symbols for the main parts of the drawings

112 and 114: first and second adsorption towers 120: compressor

210: heater 190: direction change valve for regeneration

260, 270: first and second directional valve

Claims (5)

delete Compressor for sucking and compressing the external humid air, the first and second adsorption tower, the first direction switching valve installed in the lower portion of the first and second adsorption tower to switch the transfer direction of the dehumidifying air and regeneration air, the first A second diverter valve installed at an upper portion of the first and second adsorption towers to switch the transfer directions of the dehumidifying air and the regeneration air; In the adsorption dehumidification system including a redirection valve for recirculation to the adsorption tower, a heater installed on the pipe communicating with the upper portion of the first and second adsorption tower, the control unit, A first step of circulating the regeneration air to one of the first and second adsorption towers by the regeneration direction switching valve; A second step of selectively driving the heater according to a temperature state in the adsorption tower; And A third step of heating and regenerating the regenerated air through the adsorption tower; The second step, Step 2-1 of detecting the temperature in the adsorption tower in which the regeneration process is performed among the first and second adsorption towers; Step 2-2 of determining whether the sensed temperature corresponds to the compression heat temperature of the compressor; And If the temperature in the adsorption column corresponds to the compression heat temperature of the compressor, the heating and regeneration method of the adsorption-type dehumidification system using the heat of compression is characterized in that it comprises a second step of heating the regeneration air to the regeneration temperature by driving the heater. . The method of claim 2, Step 2-1, the heating and regeneration method of the adsorption-type dehumidification system using the heat of compression, characterized in that for detecting the lower temperature in the adsorption tower by a temperature sensor. The method of claim 2, In the step 2-2, the heat of compression of the compressor is heat regeneration method of the adsorption type dehumidification system using the heat of compression, characterized in that 90 ~ 150 ℃. The method of claim 2, In the step 2-3, the regeneration temperature is heat regeneration method of the adsorption type dehumidification system using the heat of compression, characterized in that 170 ~ 250 ℃.

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