JP4336289B2 - Method for adjusting gas concentration in dehumidification of compressed gas and dehumidifier for compressed gas - Google Patents

Description

  The present invention relates to a gas concentration adjusting method and a compressed gas dehumidifying device in compressed gas dehumidification using an adsorbent.

Conventional adsorbent dehumidifiers (also referred to as “heatless dryers”) continuously discharge and supply dry gas (air), so adsorbents such as activated alumina, silica gel, synthetic zeolite, or lithium chloride Are provided with two adsorption towers (tubular containers).
Wet compressed air is introduced into one adsorption tower to perform adsorption drying, and the obtained dry air is supplied to a predetermined supply destination. At the same time, a part of the obtained dry air is guided to the other adsorption tower, and moisture is desorbed from the adsorbent with reduced moisture absorption capacity in the previous drying process, and this moisture is purged from the adsorption tower. Then, the adsorbent is regenerated. In this regeneration step, generally, about 20% of the obtained dry air is released into the atmosphere.
The drying process of the compressed air in one adsorption tower and the regeneration process of the adsorbent in the other adsorption tower are simultaneously performed in parallel. These drying and regeneration steps are alternately performed between the two adsorption towers. For example, the switching valve connected to both adsorption towers is switched every predetermined time. Thereby, dry air can be continuously supplied to a predetermined supply destination as product air.

A specific example of such a heatless dryer apparatus has already been proposed by the present applicant. (See Patent Document 1).
JP 2000-350917 A (first page)

The configuration of this heatless dryer apparatus will be described below with reference to FIGS. FIG. 12 is a cross-sectional view for explaining a main part of the heatless dryer apparatus, and FIG. 13 is a circuit diagram of the heatless dryer apparatus of FIG.
This apparatus includes a first adsorption tower 10 and a second adsorption tower 20 which are two adsorption towers. In each of the adsorption towers 10 and 20, the adsorbent 1 is filled between the upper and lower porous plates 2a and 2b.
Compressed air is introduced into each of the adsorption towers 10 and 20 through the switching control valve 50 configured as a five-port valve from the compressed gas introduction path 40 through the compressed air introduction port 40a.
The switching control valve 50 is provided with a first port a, a second port b, a third port c, a fourth port d, and a fifth port e in order from the left side to the right side of the figure. As the valve body f moves (slides), the ports a to e are switched to each other. The valve body f is driven by a solenoid 50a. The solenoid 50a is electrically connected to the control circuit 60 and is driven and controlled. The solenoid 50a may be appropriately controlled via a control circuit 60 that receives a signal from the humidity sensor 61 as in the specific example of FIG.

In the state of FIG. 12, the compressed air introduction port 40 a communicates with the second suction passage 21, and the compressed air is introduced into the second adsorption tower 20. The compressed air is dried by the adsorbent 1, and the dry air is discharged to the product air discharge collecting path 42 through the second discharge passage 22 which is also the valve chamber of the check valve 27. When the valve body f slides to the right side in the drawing, the compressed air introduction port 40a and the first suction passage 11 communicate with each other and the compressed air is introduced into the first adsorption tower 10. At that time, the dry air is discharged to the product air discharge collecting passage 42 through the first discharge passage 12 which is also the valve chamber of the check valve 17.
In parallel with the process of discharging the dry air, which is the product air, a process for regeneration of the adsorbent 1 is performed. In the state of FIG. 12, a part of the compressed air dried in the second adsorption tower 20 is introduced into the first adsorption tower 10 through the inter-adsorption tower connection path 30 provided with the purge orifice 31. The compressed air introduced in this manner regenerates the adsorbent 1 and then the first purge exhaust passage 13 and the purge exhaust from the first intake passage 11 functioning as the purge air exhaust passage via the switching control valve 50. The exhaust gas passes through the collecting passage 34 and is further exhausted through the purge opening / closing valve 32 and the purge silencer 33. When the valve element f slides to the right in the figure, the second suction passage 21, the switching control valve 50, the second purge exhaust passage 23, the purge exhaust collecting passage 34, the purge on-off valve 32, and the silencer Exhaust through 33.

By the way, the quality of the compressed air discharged from the heatless dryer described above can satisfy the required air cleanliness by adding a device such as a filter when clean air is required.
However, since the gas concentration at the outlet (also referred to as “gas concentration”) depends on the adsorption characteristics of the adsorbent, the gas concentration at the outlet can be appropriately controlled only by the configuration of the conventional compressed air dehumidifier. could not.
For example, a heatless dryer apparatus that can obtain dry air with a dew point of −60 ° C. and can stably supply oxygen at 21% does not exist as a single apparatus. This is because, in a heatless dryer device that obtains dry air with a dew point of −60 ° C., nitrogen gas is adsorbed by the adsorbent, so that the oxygen gas concentration of the outlet air (product air) relatively increases. For this reason, there exists a problem that dry air (product air) provided with a fixed property cannot be supplied continuously.
On the other hand, conventionally, a diversion system using a heatless dryer device and a gas adjusting device has been often used to control the gas concentration. That is, a method of adjusting the gas concentration with respect to the air after the outlet of the heatless dryer device has been adopted.

The problem to be solved regarding the gas concentration adjusting method and the compressed gas dehumidifying device in the dehumidification of the compressed gas is that the conventional gas concentration adjusting method requires a heatless dryer device, various gas generators and mixing devices. The apparatus becomes complicated and large, and the cost increases.
Therefore, an object of the present invention is to provide a gas concentration adjusting method and a compressed gas dehumidifying device in dehumidification of compressed gas that do not require various gas generators and mixing devices.

The present invention has the following configuration in order to achieve the above object.
According to one mode of the gas concentration adjustment method in the dehumidification of compressed gas according to the present invention, the compressed gas is guided to one of the two adsorption towers filled with the adsorbent, and the moisture of the compressed gas is adsorbed and dehumidified. A drying process for discharging the dry gas, and a part of the compressed gas dried by the drying process is led to the other adsorption tower where the moisture of the compressed gas is adsorbed and dehumidified in the previous process, thereby reducing the adsorption capacity The moisture is desorbed from the exhaust gas and exhausted to regenerate the adsorbent in parallel. The drying step and the regeneration step are performed alternately between the two adsorption towers for drying. In the gas concentration adjustment method in the dehumidification of the compressed gas that continuously discharges the gas, in order to adjust the component concentration of the dry gas that is changed by the gas other than moisture being adsorbed by the adsorbent in the drying step, The drying Characterized by evacuating the part of the body.

  Moreover, according to one form of the gas concentration adjusting method in the dehumidification of the compressed gas according to the present invention, the gas is air, and each drying step discharged from each adsorption tower in order to make the oxygen concentration constant. It is possible to exhaust the initial dry air.

  Further, according to one embodiment of the compressed gas dehumidifying device according to the present invention, the compressed gas is guided to one of the two adsorption towers filled with the adsorbent, and the moisture of the compressed gas is adsorbed and dehumidified. A drying means for performing a drying process for discharging a dry gas, and a part of the compressed gas dried by the drying process is led to the other adsorption tower in which the moisture of the compressed gas is adsorbed and dehumidified in the previous process, thereby reducing the adsorption capacity Regeneration means for regenerating the adsorbent by desorbing moisture from the adsorbent and exhausting the adsorbent in parallel with the drying step, and the drying step and the regeneration step are substantially performed between the two adsorption towers. In the compressed gas dehumidifying device comprising the drying means and the control means for controlling the regeneration means so as to continuously discharge the dry gas by alternately performing, the gas other than moisture in the drying step Adsorbed by the adsorbent To adjust the component concentration of the dry gas to be varied by a, characterized in that it comprises a concentration adjusting means of the gas component for exhausting a portion of the drying gas.

Further, according to one embodiment of the compressed gas dehumidifying device according to the present invention, a first adsorption tower and a second adsorption tower filled with an adsorbent that adsorbs and dehydrates the moisture of the introduced compressed gas, and A first suction passage for guiding compressed gas to the first adsorption tower; a second suction passage for guiding compressed gas to the second adsorption tower; a first discharge passage for discharging dry gas from the first adsorption tower; A second discharge passage for discharging dry gas from the second adsorption tower, a connection path between the adsorption towers communicating the first adsorption tower and the second adsorption tower, and a part dried by the second adsorption tower A first purge exhaust passage for exhausting compressed gas which is guided to the first adsorption tower through the connection path between the adsorption towers and desorbs moisture from the adsorbent to regenerate the adsorbent; and the first adsorption tower Part of the dried product is led to the second adsorption tower via the connection path between the adsorption towers and adsorbed. A second purge exhaust passage for exhausting the compressed gas that has been desorbed from moisture and regenerated the adsorbent, the first suction passage, the second suction passage, the first discharge passage, the second discharge passage, the first In a compressed gas dehumidifying device comprising an opening / closing means for opening and closing each of the purge exhaust passage and the second purge exhaust passage, and an opening / closing control means for controlling the opening / closing means, the dry gas of the first adsorption tower A first opening that is connected so as to communicate with the discharge side and is opened and closed is configured to exhaust a part of the dry gas discharged from the first adsorption tower when adjusting the component concentration of the dry gas. Concentration adjusting exhaust passage, and connected to the dry gas discharge side of the second adsorption tower so as to be opened and closed, and discharged from the second adsorption tower when the dry gas component concentration is adjusted Exhaust some of the dry gas A second concentration adjusting exhaust passage that is opened in this manner, an opening / closing means for opening / closing each of the first concentration adjusting exhaust passage and the second concentration adjusting exhaust passage, and an opening / closing control means for controlling the opening / closing means. It can be characterized by comprising.

  Further, according to one embodiment of the compressed gas dehumidifying device according to the present invention, the first suction that is connected to the first suction passage and the first purge exhaust passage and switches between opening and closing of the both passages as the opening / closing means. A side control valve, a second suction side control valve connected to the second suction passage and the second purge exhaust passage to switch between opening and closing of both passages, the first discharge passage, and the first concentration adjusting exhaust. A second discharge side control valve that is connected to the passage and switches between opening and closing of the both passages; and a second discharge side control that is connected to the second discharge passage and the second concentration adjusting exhaust passage and switches between opening and closing of both passages. And a valve.

Moreover, according to one form of the compressed gas dehumidification apparatus concerning this invention, the said opening / closing control means is equipped with the control apparatus which controls the opening / closing timing of the said opening / closing means by the set time interval, It is characterized by the above-mentioned. it can.
Further, according to one embodiment of the compressed gas dehumidifying device according to the present invention, the opening / closing control means includes a gas concentration sensor for measuring a gas component concentration, and the opening / closing means based on information from the gas concentration sensor. And a control device for controlling the opening / closing timing.

  According to the gas concentration adjusting method and compressed gas dehumidifying device of the present invention for dehumidifying compressed gas, it is possible to obtain product air having a desired dryness and gas component concentration without requiring various gas generators and mixing devices. Can do. Therefore, there is an advantageous effect that the apparatus does not become complicated and large, and the cost does not increase.

Hereinafter, an example of the best mode of a dehumidifying device for compressed gas according to the present invention will be described in detail with reference to the accompanying drawings (FIGS. 1 to 8). FIG. 1 is a circuit diagram illustrating a compressed gas dehumidifier according to the present invention. FIG. 2 is a time chart of the embodiment of FIG. 3 to 8 are circuit diagrams for explaining the operating state of the embodiment of FIG.
10 is a 1st adsorption tower, 20 is a 2nd adsorption tower. Hereinafter, in order to simplify the description, the first adsorption tower 10 may be referred to as “A tower” and the second adsorption tower 20 may be referred to as “B tower”. The first adsorption tower 10 (A tower) and the second adsorption tower 20 (B tower) are filled with an adsorbent that adsorbs and dehumidifies the moisture of the introduced compressed gas.

Reference numeral 11 denotes a first suction passage, which is a passage that guides compressed gas to the A tower. Reference numeral 21 denotes a second suction passage, which is a passage for guiding compressed gas to the B tower.
Reference numeral 12 denotes a first discharge passage, which is a passage through which dry gas is discharged from the A tower. Reference numeral 22 denotes a second discharge passage, which is a passage through which dry gas is discharged from the B tower.
The first suction passage 11, the second suction passage 21, the first discharge passage 12, and the second discharge passage 22 have opening / closing means (described later) for opening / closing the passages, and opening / closing for controlling the opening / closing means. Control means 55 (connection state not shown) is provided.
Thus, there is provided a drying means for performing a drying process in which the compressed gas is guided to one of the two adsorption towers 10 and 20 filled with the adsorbent and the moisture of the compressed gas is adsorbed and dehumidified to discharge the dry gas. It is configured.

Reference numeral 30 denotes a connection path between the adsorption towers, which is a passage that connects the A tower and the B tower. This inter-adsorption tower connection path 30 is connected to the side where the discharge passages 12, 22 of the respective adsorption towers 10, 20 are communicated. This is because, instead of the compressed air that has just been sucked into the adsorption towers 10 and 20 and contains moisture, the dried compressed gas is guided from one adsorption tower to the other adsorption tower.
Further, a purge orifice 31 is provided in the inter-adsorption tower connection path 30 as means for adjusting the gas flow rate. Thereby, the compressed air of a fixed flow volume passes.
Reference numeral 13 denotes a first purge exhaust passage, and a part dried in the tower B is led to the tower A via the inter-adsorption tower connection passage 30 to desorb moisture from the adsorbent and regenerate the adsorbent. It is a passage for exhausting compressed gas. Reference numeral 23 denotes a second purge exhaust passage, and a part of the air dried by the tower A is led to the tower B via the inter-adsorption tower connecting passage 30 to desorb moisture from the adsorbent and regenerate the adsorbent. It is a passage for exhausting compressed gas.
Each of the first purge exhaust passage 13 and the second purge exhaust passage 23 is provided with opening / closing means (described later) for opening / closing each passage, and an opening / closing control means 55 for controlling the opening / closing means. .
As a result, a part of the compressed gas dried in the drying process is led to the other adsorption tower where the moisture of the compressed gas is adsorbed and dehumidified in the previous process, and the moisture is desorbed and exhausted from the adsorbent whose adsorption capacity is reduced. The regeneration means for regenerating the adsorbent is performed in parallel with the drying process.

Reference numeral 14 denotes a first concentration adjusting exhaust passage, which is a passage for exhausting a part of the dry gas discharged from the tower A in order to adjust the component concentration of the dry gas. Reference numeral 24 denotes a second concentration adjusting exhaust passage, which is a passage for exhausting a part of the dry gas discharged from the tower B in order to adjust the component concentration of the dry gas.
Each of the first concentration adjusting exhaust passage 14 and the second concentration adjusting exhaust passage 24 is provided with opening / closing means (described later) for opening and closing each passage, and an opening / closing control means 55 for controlling the opening / closing means. .
Thereby, by exhausting a part of the dry gas, the gas component concentration adjusting means for adjusting the component concentration of the dry gas which is changed by adsorbing the gas other than moisture by the adsorbent in the drying process. It is configured.

Next, the opening / closing means of this embodiment will be described in detail.
Reference numeral 15 denotes a first suction side control valve which is connected to the first suction passage 11 and the first purge exhaust passage 13 and serves as an opening / closing means for switching between opening and closing of both passages. It is connected to the compressed gas suction side of Tower A.
Similarly, reference numeral 25 denotes a second suction side control valve which is connected to the second suction passage 21 and the second purge exhaust passage 23 and serves as an opening / closing means for switching between opening and closing of both passages. It is connected to the compressed gas suction side of the B tower.
Reference numeral 16 denotes a first discharge side control valve which is connected to the first discharge passage 12 and the first concentration adjusting exhaust passage 14 and serves as an opening / closing means for switching opening and closing of both passages. It is connected to the compressed gas discharge side of the A tower.
Similarly, reference numeral 26 denotes a second discharge side control valve which is connected to the second discharge passage 22 and the second concentration adjusting exhaust passage 24 and serves as an opening / closing means when switching between the two passages is switched. It is connected to the compressed gas discharge side of the B tower.

By the first suction side control valve 15, the second suction side control valve 25, the first discharge side control valve 16, and the second discharge side control valve 26, the first suction passage 11, the second suction passage 21, and the first discharge are described. Opening / closing means for opening / closing the passage 12, the second discharge passage 22, the first purge exhaust passage 13, the second purge exhaust passage 23, the first concentration adjusting exhaust passage 14, and the second concentration adjusting exhaust passage 24 Is configured.
Further, the opening / closing means and the opening / closing control means 55 for controlling the opening / closing means are such that the drying process and the regeneration process are alternately performed between the two adsorption towers so that the drying gas is continuously discharged. The control means controls the reproduction means. The opening / closing means and the opening / closing control means 55 are also control means for controlling the gas component concentration adjusting means.

Next, based on FIG. 1, other configurations attached to the present embodiment and details of each communication path will be described.
Reference numeral 40 denotes a compressed gas introduction path, which is a gas passage connected to the compressed gas generation source side to guide the compressed gas. The compressed gas introduction passage 40 is branched to form a first suction passage 11 and a second suction passage 21.
A suction-side on-off valve 41 is connected to the middle part of the compressed gas introduction path 40. The suction side on-off valve 41 is controlled to open when the dehumidifying device of the present embodiment starts operation, and to close when the operation is stopped, and to manage the introduction of compressed gas into the adsorption towers 10 and 20. It is a valve.
11a is a 1st suction | inhalation side communication path, and is connected so that the 1st suction | inhalation side control valve 15 and A tower may be connected. The first suction side communication passage 11a is a part of each of the first suction passage 11 and the first purge exhaust passage 13, and is a shared passage.
Similarly, 21a is a 2nd suction | inhalation side communication path, and is connected so that the 2nd suction | inhalation side control valve 25 and B tower | tube may be connected. The second suction side communication passage 21a is a part of each of the second suction passage 21 and the second purge exhaust passage 23, and is a shared passage.

Moreover, 12a is a 1st discharge side communication path, and is connected so that the 1st discharge side control valve 16 and A tower may be connected. The first discharge side communication passage 12a is a part of each of the first discharge passage 12 and the first concentration adjusting exhaust passage 14, and is a common passage.
Similarly, 22a is a 2nd discharge side communication path, and is connected so that the 2nd discharge side control valve 26 and the B tower may be connected. The second discharge side communication passage 22a is a part of each of the second discharge passage 22 and the first concentration adjusting exhaust passage 24, and is a shared passage.
Reference numerals 17 and 27 are check valves, which are provided in the middle of each of the first discharge passage 12 and the second discharge passage 22. The check valves 17 and 27 are check valves that prevent the dry gas discharged as the product gas from being suitably discharged and prevent backflow.

Reference numeral 42 denotes a product gas discharge collecting passage, which is a passage in which the first discharge passage 12 and the second discharge passage 22 are gathered. The dry gas is supplied to a predetermined supply destination through the product gas discharge collecting path 42.
Reference numeral 43 denotes a discharge-side on-off valve, which is connected to a middle portion of the product gas discharge collecting passage 42 and is an electromagnetic valve that is controlled and operated so as to manage the discharge of the product gas. In the present embodiment, the opening / closing control means 55 controls to close for a predetermined time at the beginning of operation until stable product gas is discharged. In addition, the predetermined time of the predetermined time at the start of operation is a time until exhaust for concentration adjustment is performed once from both of the adsorption towers 10 and 20 at a time.
Reference numeral 44 denotes a discharge port orifice, which is provided in the product gas discharge collecting passage 42 as means for adjusting the discharge flow rate of the dry gas (product gas). Thereby, a product gas having a constant flow rate is discharged.

Reference numeral 32 denotes a purge opening / closing valve which is connected to the first purge exhaust passage 13 and the second purge exhaust passage 23 and is operated by being controlled by the opening / closing control means 55 so as to manage the purge exhaust. is there.
Reference numeral 34 denotes a purge exhaust collecting passage, which is a passage in which the first purge exhaust passage 13 and the second purge exhaust passage 23 are gathered. That is, the purge exhaust collecting passage 34 constitutes a part of each of the first purge exhaust passage 13 and the second purge exhaust passage 23.
Reference numeral 33 denotes a purge silencer, which is connected to the exhaust side of the purge opening / closing valve 32. It is provided to mute the exhaust sound during purging.

Reference numeral 35 denotes a concentration adjusting exhaust collecting passage, which is a passage in which the first concentration adjusting exhaust passage 14 and the second concentration adjusting exhaust passage 24 are gathered. In other words, the concentration adjusting exhaust collecting passage 35 constitutes a part of each of the first concentration adjusting exhaust passage 14 and the second concentration adjusting exhaust passage 24.
Reference numeral 36 denotes a concentration adjusting exhaust orifice, which is provided in the concentration adjusting exhaust collecting path 35 as means for adjusting the concentration adjusting exhaust flow rate. As a result, the exhaust gas for adjusting the concentration at a constant flow rate passes.
A concentration adjusting exhaust silencer 37 is connected to the end of the concentration adjusting exhaust collecting path 35. It is provided to mute the exhaust sound at the time of exhaust for concentration adjustment.

Next, the operation of the present embodiment will be described in detail with reference to FIGS.
The time chart of FIG. 2 shows the passage of time and changes in the energization state (ON / OFF state) applied to the solenoids that actuate each control valve and each on-off valve, and the passage of time and product air (when dehumidifying compressed air) Shows the difference between the adsorption towers discharging the gas to a predetermined supply destination, the passage of time, and the change in oxygen concentration in the towers A and B (when dehumidifying compressed air).
Moreover, the circuit diagrams of FIGS. 3 to 8 sequentially show operating states that change with time.
In the state shown in FIG. 1, all the solenoids are not energized, and the control valves and on-off valves are in an OFF state. That is, the entire apparatus is in an OFF state.
In addition, when the operation of the dehumidifying device of the present embodiment is started, the suction side on-off valve 41 is in a state where electricity is turned on (ON), and the valve is opened, and remains on during the operation. Further, the discharge-side on / off valve 43 is in the OFF state for a predetermined time at the beginning of the operation, but continues to be in the ON state thereafter.
As described above, the suction-side on-off valve 41 and the discharge-side on-off valve 43 are not shown in the circuit diagrams of FIGS. Hereinafter, with reference to FIGS. 3 to 8, the first suction side control valve 15, the second suction side control valve 25, the first discharge side control valve 16, the second discharge side control valve 26, and the purge opening / closing valve 32 are focused on. The operation of the embodiment will be described.

As shown in the time chart of FIG. 2, when one cycle immediately after the start of operation is completed and the discharge side on-off valve 43 (see FIG. 1) is turned on and the product gas discharge collecting passage 42 is opened. At the same time, the solenoid of the first discharge side control valve 16 is energized, and the first discharge side control valve 16 is turned on. Further, the first suction side control valve 15 is turned off.
Then, as shown in FIG. 3, the first suction passage 11 is opened by the first suction side control valve 15, the compressed gas is guided to the A tower, and the drying process is started. Further, the flow path is switched by the first discharge side control valve 16 so that the first concentration adjusting exhaust passage 14 is opened, and the dry gas discharged from the tower A is exhausted.
At this time, since the second suction side control valve 25, the second discharge side control valve 26, and the purge opening / closing valve 32 are OFF, the second suction passage 21 and the second discharge passage 22 are opened, and the second The first purge exhaust passage 13 and the second purge exhaust passage 23 are closed. For this reason, the dry gas discharged through the B tower is discharged through the second discharge passage 22 as a product gas.

The dry gas exhausted from the first concentration adjusting exhaust passage 14 when the first discharge side control valve 16 is ON is obtained by drying the initial compressed gas immediately after the compressed gas is introduced to the A tower. is there.
According to this, as shown in FIG. 2, the dry gas in which the specific gas component density | concentration changed in A tower can be exhausted suitably. Thereby, the gas component density | concentration of dry gas can be stabilized. When the compressed gas is compressed air and the adsorbent is synthetic zeolite, dry air at the initial stage of each drying step discharged from the adsorption towers 10 and 20 (drying with a high oxygen concentration as shown in FIG. 2) The oxygen concentration can be made constant by exhausting the air.

By the way, for example, when adsorbing moisture in dehumidification of compressed gas, the adsorbent may adsorb a specific gas component (gas component) and change the gas component concentration at the same time.
For example, when the synthetic zeolite is used as an adsorbent for dehumidifying compressed air, the present inventor has found a special characteristic relating to a phenomenon of adsorbing nitrogen gas in the air.
This adsorption phenomenon is that nitrogen gas is selectively adsorbed within a short time immediately after the synthetic zeolite is regenerated in the above-described regeneration step. However, the capacity capable of adsorbing the nitrogen gas is small, and the adsorption capacity with respect to the nitrogen gas rapidly decreases within a short time. According to this, although temporarily, the oxygen concentration rapidly increases, the gas component concentration is changed. From this phenomenon, as described above, the oxygen concentration of the product air can be stabilized by exhausting the dried air in a short time immediately after the drying process is started in each of the adsorption towers 10 and 20.
The present invention is not limited to this, and in the case of other conditions such as other target gases or other adsorbents, part of the adsorbed gas (dry gas) corresponding to the adsorption characteristics of each gas component is used. If the timing of exhausting and the length of time are selectively set, a product gas composed of a desired gas component can be obtained.

  Next, as shown in FIG. 2, the first discharge side control valve 16 is turned OFF, and the second suction side control valve 25 and the purge opening / closing valve 32 are turned ON. Then, since the second purge exhaust passage 23 is opened as shown in FIG. 4, a part of the compressed gas dried in the A tower is led to the B tower, and the regeneration process of the B tower starts. At the same time, the dry gas that has passed through the tower A (dry air when processing compressed air) is discharged through the first discharge passage 12 as product gas (product air). At this time, the oxygen concentration in the tower A has already returned to the original state as shown in FIG. 2, and product air with a constant oxygen concentration is discharged.

  Next, as shown in FIG. 2, when the purge on-off valve 32 is turned off, both the second purge exhaust passage 23 and the second suction passage 21 are closed as shown in FIG. Thereby, a part of the compressed gas dried in the A tower is not exhausted for purging but is led to the B tower so as to increase the pressure in the B tower in advance. In addition, the dry gas which passed A tower is continuously discharged through the 1st discharge passage 12 as product gas.

Next, as shown in FIG. 2, the second suction side control valve 25 is turned OFF and the second discharge side control valve 26 is turned ON. Then, as shown in FIG. 6, the second suction passage 21 is opened and the compressed gas is guided to the B tower, and the second concentration adjusting exhaust passage 24 is opened and discharged from the B tower. The dry gas is exhausted.
The dry gas (for example, dry air) exhausted from the second concentration adjusting exhaust passage 24 is obtained by drying the initial compressed air immediately after the compressed gas (for example, compressed air) is introduced into the B tower. According to this, as shown in FIG. 6, the dry air whose oxygen concentration increased in the B tower can be suitably exhausted. Thereby, the gas component density | concentration of dry air can be stabilized. The dry air that has passed through the tower A is continuously discharged through the first discharge passage 12 as product air.

  Next, as shown in FIG. 2, the second discharge side control valve 26 is turned OFF, and the first suction side control valve 15 and the purge opening / closing valve 32 are turned ON. Then, since the first purge exhaust passage 13 is opened as shown in FIG. 7, a part of the compressed gas dried in the B tower is led to the A tower, and the regeneration process of the A tower starts. At the same time, the dry gas (dry air) that has passed through the tower B is discharged through the second discharge passage 22 as product gas (product air). At this time, the oxygen concentration in the column B has already returned to the original state as shown in FIG. 2, and product air with a constant oxygen concentration is discharged.

  Next, as shown in FIG. 2, when the purge on-off valve 32 is turned OFF, both the first purge exhaust passage 13 and the first suction passage 11 are closed as shown in FIG. Thereby, a part of the compressed gas dried in the tower B is not exhausted for purging but is led to the tower A so as to increase the pressure in the tower B in advance. In addition, the dry gas which passed the B tower is continuously discharged through the 2nd discharge passage 22 as product gas.

And in this embodiment, 1 cycle is complete | finished by the process of FIGS. 3-8 demonstrated above, and the same cycle is performed sequentially continuously. That is, the control valves 15, 25, 16, 26 and the purge on / off valve 32 are opened / closed at predetermined intervals by the on / off control means 55 to perform continuous operation. The opening / closing control means 55 includes a control device that controls the opening / closing timing of the opening / closing means (each control valve and each opening / closing valve) at a set time interval.
The time for one cycle may be set to about 4 minutes, for example.

According to this embodiment, when processing compressed air by controlling the opening / closing means (each control valve and each opening / closing valve), high oxygen concentration air that has passed through the adsorbent is released into the atmosphere, and oxygen in the outlet air An increase in concentration can be prevented. Thereby, the air which satisfy | fills the conditions of the dryness of dry air and gas concentration (air with constant oxygen concentration) simultaneously can be obtained.
2 and 3-8, during the operation of this embodiment, dry air is discharged (discharged) as product air from either the A tower or the B tower. That is, dry air can be continuously supplied to a predetermined supply destination as product air.
As described above, according to the gas concentration adjusting method and the compressed gas dehumidifying device in the dehumidification of the compressed gas of the present embodiment, a dry gas having a stable gas concentration component can be continuously produced without the need for various gas generators and mixing devices. Can be supplied.
Therefore, according to this embodiment, there is an advantageous effect that the apparatus can be manufactured at a low cost without being complicated and enlarged.

A compressed gas dehumidifier according to a first embodiment of the present invention will be described with reference to the accompanying drawing (FIG. 9). FIG. 9 is a circuit diagram of a compressed gas dehumidifier according to the first embodiment. In addition, about the structure same as the structure of the said embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.
Reference numeral 45 denotes a gas concentration sensor, which is attached to the product gas discharge collecting passage 42 and measures the gas component concentration. In the case of the present embodiment, the sensor measures the oxygen concentration.
A control device 56 is electrically connected to the gas concentration sensor 45, and controls the opening / closing timing of the opening / closing means described above based on information (signal) from the gas concentration sensor 45. As described above, the gas concentration sensor 45 and the control device 56 constitute the open / close control means 55. The gas concentration sensor 45 and the control device 56 may use known techniques as appropriate.

Further, the form of the gas concentration sensor 45 may be a system in which the gas in the product gas discharge collecting path 42 is directly measured, or a system in which the gas is sampled and measured by a predetermined suction pipe.
According to this configuration, it is possible to measure the oxygen concentration of the product gas (air) and control the opening and closing of the discharge side control valves 16 and 26 according to the change in the air concentration. According to this, unnecessary dry air having a high oxygen concentration can be exhausted at an appropriate time and period. Therefore, while maintaining the quality of the dry air discharged as product air suitably, the amount of dry air exhausted can be reduced and product air can be supplied efficiently.
In the case of controlling by measuring the gas concentration, the time for exhausting through the discharge side control valves 16 and 26 is constantly changed and becomes constant, but the drying process, the regeneration process and the exhaust process (gas concentration adjustment process) are performed. The fact that the adsorption towers 10 and 20 are substantially alternate is not changed.
Reference numerals 18, 28, and 46 are pressure sensors, which are generally provided for confirming the operation status of the present apparatus. The pressure sensors 18, 28, and 46 are electrically connected to the opening / closing control means 55 (not shown), and the apparatus is controlled based on information detected by these pressure sensors.

A compressed gas dehumidifying device according to a second embodiment of the present invention will be described with reference to the accompanying drawings (FIGS. 10 and 11). FIG. 10 is a circuit diagram of a compressed gas dehumidifier according to the second embodiment. Moreover, FIG. 11 is a time chart of Example 2, and the process of processing compressed air is shown. In addition, about the structure same as the structure of background art mentioned above, embodiment, and Example 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.
A direction control valve 52 is connected to the outlet side of the product gas discharge collecting passage 42a, and supplies product air (dry air) to a predetermined supply destination or exhausts part of the dry air. It is a switching valve.

Next, the operation of the second embodiment will be described in detail based on FIG. 10 and FIG.
In the time chart of FIG. 11, the passage of time and changes in the ON / OFF states applied to the solenoids of the control valves and the on-off valves are shown.
In the state shown in FIG. 10, all the solenoids are not energized, and the control valves and the on-off valves are in an OFF state. That is, the entire apparatus is in an OFF state.
When the operation of the dehumidifying device for compressed air is started, the intake side on-off valve 41 is switched on (ON) and the valve is opened, and that state is maintained during operation. Further, the discharge-side on / off valve 43 is in the OFF state for a predetermined time at the beginning of the operation, but continues to be in the ON state thereafter.
Thus, the suction side on-off valve 41 and the discharge side on-off valve 43 do not open and close at a constant cycle. Therefore, in the following, the operation of the second embodiment will be described focusing on the switching control valve 50, the purge on-off valve 32, and the direction control valve 52.

As shown in the time chart of FIG. 11, after the operation is started and one cycle immediately after the start is completed, the discharge-side on / off valve 43 is turned on and the product gas discharge collecting path 42 is opened. At this time, all of the switching control valve 50, the purge on-off valve 32, and the direction control valve 52 are in an OFF state. Therefore, the gas (dry air) that has passed through the B tower is exhausted through the direction switching valve 52 and the concentration adjusting exhaust silencer 37.
When the solenoid of the switching control valve 50 is energized and turned on after a predetermined time, the switching control valve 50 opens the first suction side communication passage 11a and the compressed air is guided to the A tower to start the drying process. Further, since the directional switching valve 52 continues to be in the OFF state, the dry air discharged from the tower A is exhausted. That is, the initial dry air discharged from the tower A is exhausted and does not become product air.
Further, the purge on-off valve 32 is turned on a little after the switching control valve 50 is turned on, and the regeneration process of the B tower is executed in parallel.
Next, the direction control valve 52 is turned ON, and dry air that is product air is supplied to a predetermined supply destination. At this time, the dry air is discharged from the A tower.
Thereafter, the purge opening / closing valve 32 is turned OFF, and the purge in the regeneration process of the B tower is completed.

Next, the switching control valve 50 and the direction control valve 52 are turned off. As a result, the second suction side communication passage 21a is opened by the switching control valve 50, and the compressed air is guided to the tower B to start the drying process. Moreover, since the direction switching valve 52 is in the OFF state, the dry air discharged from the B tower is exhausted. That is, the initial dry air discharged from the tower B is exhausted and does not become product air.
Further, the purge on-off valve 32 is turned on a little after the switching control valve 50 is turned on, and the regeneration process of the A tower is executed in parallel.
Next, the direction control valve 52 is turned ON, and dry air that is product air is supplied to a predetermined supply destination. At this time, the dry air is discharged from the B tower.
Thereafter, the purge on-off valve 32 is turned off, and the purge in the regeneration process of the A tower is completed.
Then, the switching control valve 50 is turned on and the direction control valve 52 is turned off.

Thus, one cycle from when the previous switching control valve 50 is turned on to when the switching control valve 50 is turned on again is completed, and thereafter the same cycle is successively executed. That is, the switching control valve 50, the purge opening / closing valve 32, and the direction switching valve 52 are opened / closed at predetermined intervals by the opening / closing control means (not shown), and continuous operation is performed.
According to the second embodiment, when used for the treatment of compressed air, the air of high oxygen concentration that has passed through the adsorbent is released into the atmosphere by the control of the opening / closing means (each control valve and each valve), and the outlet An increase in the oxygen concentration of air can be prevented. Thereby, the air which satisfy | fills the conditions of the dryness of dry air and gas concentration (air with constant oxygen concentration) simultaneously can be obtained.

In Example 2, product air is intermittently discharged, but dryness and gas concentration of dry air can be obtained with suitable quality. Therefore, according to this, it is possible to suitably supply dry air having a stable gas concentration component without requiring various gas generators and mixing devices.
Further, in order to continuously supply the product air in the second embodiment, the product air may be supplied to the pressure chamber (chamber) and retained. In this case, a chamber is required, but it can be easily provided as compared with various gas generators and mixing devices.
Therefore, according to the second embodiment, there is an advantageous effect that the apparatus can be manufactured at a low cost without being complicated and enlarged.

  As described above, the present invention has been variously described with reference to preferred embodiments. However, the present invention is not limited to these embodiments, and it is needless to say that many modifications can be made without departing from the spirit of the invention. That is.

It is a circuit diagram showing one embodiment of a dehumidifying device for compressed gas according to the present invention. It is a time chart of embodiment of FIG. It is a circuit diagram which shows the operation state of embodiment of FIG. It is a circuit diagram which shows the operation state of embodiment of FIG. It is a circuit diagram which shows the operation state of embodiment of FIG. It is a circuit diagram which shows the operation state of embodiment of FIG. It is a circuit diagram which shows the operation state of embodiment of FIG. It is a circuit diagram which shows the operation state of embodiment of FIG. It is a circuit diagram which shows Example 1 concerning this invention. It is a circuit diagram which shows Example 2 concerning this invention. 6 is a time chart of Example 2. It is sectional drawing explaining a prior art. It is a circuit diagram of the prior art of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 1st adsorption tower 11 1st suction passage 12 1st discharge passage 13 1st purge exhaust passage 14 1st concentration adjustment exhaust passage 15 1st suction side control valve 16 1st discharge side control valve 20 2nd adsorption tower 21 Second suction passage 22 Second discharge passage 23 Second purge exhaust passage 24 Second concentration adjusting exhaust passage 25 Second suction side control valve 26 Second discharge side control valve 30 Adsorption tower connection passage 32 Purge opening / closing valve 41 Suction side open / close valve 43 Discharge side open / close valve 45 Gas concentration sensor

Claims (1)

A drying step of discharging the dry gas by introducing the compressed gas to one of the two adsorption towers filled with the adsorbent and the moisture of the compressed gas being adsorbed and dehumidified;
A part of the compressed gas dried in the drying step is led to the other adsorption tower where the moisture of the compressed gas is adsorbed and dehumidified in the previous step, and the moisture is desorbed and exhausted from the adsorbent whose adsorption capacity is reduced. In parallel with the regeneration process to regenerate the adsorbent,
By continuously performing these drying steps and regeneration steps alternately between the two adsorption towers, the dry gas is continuously discharged,
Gas concentration adjustment method in dehumidification of compressed gas for exhausting a part of the dry gas in order to adjust the component concentration of the dry gas which is changed by adsorbing gas other than moisture in the adsorbent in the drying step The gas in the dehumidification of compressed gas, wherein the gas is air and the initial dry air of each drying step discharged from each adsorption tower is exhausted to make the oxygen concentration constant. Density adjustment method.

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