JP2673300B2 - Low concentration gas sorption machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to a gas which reversibly absorbs or adsorbs moisture (hereinafter referred to as gas) or other active gas (hereinafter referred to as gas) in a rotor having a large number of small through holes. A low-concentration gas sorption machine which is formed of a sheet containing a sorbent, and through which a processing gas and a regeneration gas are alternately passed through the small through-holes to obtain a gas removed by sorption, for example, dry air It is a thing.

2. Description of the Related Art A rotor having a large number of small through holes, that is, a honeycomb rotor is formed by using a hygroscopic agent that reversibly adsorbs moisture, two rotors are used, and a gas to be treated is used as a first stage rotor. After passing through dehumidification, it is cooled and then passed through the second stage rotor to be further dehumidified, and the regeneration gas is passed through the regeneration zone of the second stage rotor and then heated and passed through the regeneration zone of the first stage rotor. Dew point-
A method for obtaining an ultra-low humidity gas at 80 ° C. or lower is disclosed in JP-A-61-71821.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the above method, two dehumidifying rotors are operated in parallel, and along with this, rotor drive devices, pipes, seal plates, etc.
Since it is necessary for a vehicle, the structure is complicated, a large installation area is required, maintenance is complicated, and manufacturing costs and operating costs are inevitable.

Means for Solving the Problems The present invention eliminates the above-mentioned drawbacks and impregnates with a gas sorbent or has a gas sorbent exposed on the surface thereof. A honeycomb rotor formed so as to have holes is formed, and each fan-shaped portion of the rotor has a first stage sorption zone, a second stage sorption zone, a precooling zone,
The two sorption zones are separated by a sector provided in the casing so as to sequentially act as a regeneration zone, and the sorption zones of the two parts form a flow passage for the gas-containing gas in series. It is configured to wear clothes. The number of stages of the sorption zone and the regeneration zone is further increased, and the first stage, the second stage,
It may be divided into the third stage.

Example 1 A kraft paper was molded to obtain a cylindrical honeycomb structure having a large number of small through holes penetrating both end surfaces, and a dehumidifier element impregnated with about 8% by weight of lithium chloride was prepared. To do.

Sectors are attached to both end surfaces of this rotor or element 1 to divide into first stage absorption zone 2, second stage absorption zone 3, precooling zone 4 and regeneration zone 5 as shown in FIG. A low-concentration gas absorber which is connected with an introduction fan 6, an air supply fan 7, a heater 8 for heating the regenerated air, a fan 9 for introducing the regenerated air, and a treatment air cooler 10 as shown in the drawing. An example of the width of each zone, that is, the central angle is the first-stage absorption zone 120, the second-stage absorption zone 120, the pre-cooling zone 30, and the regeneration zone 90.

Example 2 A low-density paper containing inorganic fibers as a main component was molded to obtain a cylindrical honeycomb structure having a large number of small through holes penetrating both end surfaces thereof, and a hygroscopic powder such as zeolite was uniformly dispersed in the honeycomb structure. A dehumidifying rotor in which the magnesium silicate aerogel formed is firmly fixed integrally is obtained. In this dehumidifying rotor, magnesium silicate aerogel acts as a gas adsorbent having a normal gas adsorbing ability, and powder such as zeolite acts as a gas adsorbent having an extremely high gas adsorbing ability with respect to a gas having a low gas concentration.

Sectors S shown in FIG. 3 are attached to both end faces of the rotor 1, and as shown in FIG. 2, a first stage adsorption zone 2, a second stage adsorption zone 3, a precooling zone 4, a first stage regeneration zone 5, a second stage
It is divided into a step-regeneration zone 11, and each of these zones is provided with a treated air introduction fan 6, an air supply fan 7, a regeneration air heating heater 8,
12, a low-concentration gas adsorber in which a fan 9 for introducing regenerated air and a treatment air cooler 10 are connected as shown in the drawing. Incidentally, as an example of the width of each zone, that is, the central angle, the first stage adsorption zone 120, the second stage adsorption zone 120, the precooling zone 40, the first stage regeneration zone 40, the second stage regeneration zone 40, Is.

Example 3 A low-density paper containing inorganic fibers as a main component was molded to obtain a cylindrical honeycomb matrix having a large number of small through holes penetrating both end surfaces, and this matrix is shown in a and b of FIG. As shown, it is divided into two parts, with the matrix of inorganic fiber as the core
A part is a dehumidifying rotor in which a synthetic zeolite is dispersed in magnesium silicate erogel, and a part b is a magnesium silicate erogel integrally formed.

Sectors S shown in FIG. 3 are attached to both end faces of the rotor 1, and as shown in FIG. 4, a first stage adsorption zone 2, a second stage adsorption zone 3, a precooling zone 4, a first stage regeneration zone 5, a second stage
It is divided into a step-regeneration zone 11, and each of these zones is provided with a treated air introduction fan 6, an air supply fan 7, a regeneration air heating heater 8,
12, a low-concentration gas adsorber in which a fan 9 for introducing regenerated air and a treatment air cooler 10 are connected as shown in the drawing. The size of each zone is almost the same as that of the second embodiment.

Operation of the Invention The process of dehumidifying air will be described with reference to the case of the first embodiment. The treated air TA to be dehumidified is dehumidified by the fan 6 into the first stage sorption zone 2 of the rotor 1, and then preferably the treated air is cooled. After passing through the vessel 10 and cooling with the cooling water 13, it is led to the second-stage sorption zone 3 to carry out the second dehumidification to obtain dehumidified air with a low dew point.
Is supplied as air supply SA.

Explaining the process of water removal or regeneration of the rotor, precooled air PA, preferably dehumidified air obtained by the above dehumidification process.
After a portion of SA is passed through the pre-cooling zone 4 to pre-cool the rotor, it is heated by the heater 8 for heating the regenerated air and is passed through the regeneration zone 5 as regenerated air RA of high temperature and low humidity to remove the moisture adsorbed on the rotor and regenerate it. .

In the case of the second and third embodiments, that is, the reproduction zone is the first.
When divided into the stage regeneration zone 5 and the second stage regeneration zone 11, precooled air PA, preferably part of the dehumidified air SA obtained by the above dehumidification process is first passed through the precooling zone 4 to precool the rotor. After being heated up to about 180 ° C. by the heater 8 for heating the regenerated air and passed through the first-stage regeneration zone 5 as the regenerated air RA ₁ of high temperature and low humidity, the moisture adsorbed on the rotor is removed,
The sorption moisture is expelled by passing the regenerated air RA ₂ whose temperature has dropped to about 100 ° C. or lower and the humidity is high, but still having the regenerating ability, through the second stage regeneration zone 11. In this case, the regeneration air can be reheated by the regeneration air heating heater 12 to improve the regeneration efficiency. That is, the relative humidity of the regenerated air RA ₁ , RA ₂ can be controlled by increasing or decreasing the temperature of the heaters 8, 12.

The above has traced how the treated air and the regenerated air interact with the rotor parts when passing through the rotor parts. In the following, it will be described how a certain part of the rotor makes one rotation in the direction of the arrow in the drawing. The third embodiment, that is, the example of FIG. 4 will be described from the viewpoint of interaction with air and regeneration air.

The rotor portion desorbed the adsorbed moisture in the regeneration zones 11 and 5 and cooled in the precooling zone 4 by the low temperature precooled air at room temperature or slightly higher than room temperature is first cooled in the second stage adsorption zone 3 after the first stage adsorption step. The treated air (Example 30 ° C.) is further dehumidified mainly by zeolite, that is, a hygroscopic agent having an extremely high adsorption performance to be air having an ultralow dew point, and then the treated air is treated in the first-stage adsorption zone 2 such as The outside air at a temperature of 20 ° C is dehumidified mainly by the metal silicate aerogel. Thus, the rotor portion which has adsorbed moisture and has a slightly elevated temperature regenerates the metal silicate aerogel by desorption and regeneration with the regeneration air RA _{2 at} about 120 ° C in the second stage regeneration zone 11, and then at about 180 ° C in the first stage regeneration zone 5. Zeolite, that is, a hygroscopic agent having a high regeneration temperature is desorbed and regenerated by the regenerated air RA ₁ , and then cooled in the precooling zone 4 to room temperature or a temperature close to room temperature through a part of precooled air, preferably dehumidified air supply SA, Repeat the process of.

In Examples 2 and 3 above, magnesium silicate aerogel is used as a gas adsorbent having ordinary gas adsorption performance, and zeolite, alumina gel, etc. is used as a gas adsorbent having an extremely high gas adsorption performance with respect to a gas containing a small concentration of gas. Using the combination of both gas adsorbents, explained an example of obtaining air with an ultra-low dew point by adsorbing moisture in the air, but instead of the magnesium silicate aerogel as a gas adsorbent having normal gas adsorption performance Aluminum silicate aerogel,
It is also possible to use silica erogel or the like and use a combination of this with zeolite, alumina gel or the like. Zeolite as a gas adsorbent, activated carbon instead of alumina gel,
Activated clay or the like may be used and such a solid adsorbent may be combined with an erogel of a silicate such as aluminum, magnesium or calcium. Further, silica gel, alumina gel and other solid adsorbents described above may be used alone.

On the other hand, as the inert gas, there are nitrogen, argon, etc. in addition to the above-mentioned air, and as the active gas to be removed contained in the inert gas, carbon monoxide, sulfur oxides, ammonia, sulfide other than the above-mentioned water vapor. There are hydrogen, organic solvent vapor, and various other odorous substances. It is possible to use only one type of gas sorbent or a combination of three or more types of gas sorbents depending on the type of the active gas in the inert gas to be sorbed and removed, and the sorption zone in three stages. It is also possible to perform a multi-stage sorption operation by classifying the above. On the other hand, the playback zone is 1
Although only one part may be used, energy can be saved as will be described later if it is divided into two or more parts and the regeneration temperature is sequentially increased to perform multi-stage regeneration.

In Example 3 above, a small amount of organic synthetic fiber was added to the paper: silica / alumina-based ceramic fiber, and the apparent specific gravity was 0.3 to 0.45, and the thickness was 0.15 to 0.
Paper made into 25 mm corrugated: 3.2 mm pitch x 1.8 mm wave height Dehumidifying rotor width: 400 mm Dehumidifying rotor diameter: 320 mmφ Temperature of treated air at inlet of 1st stage adsorption zone 15 ° C Temperature of treated air at inlet of 2nd stage adsorption zone 11 ° C Temperature of the regenerated air at the inlet of the first and second regeneration zones
150 ℃ Air velocity of treated air 1.5m / sec. Wind velocity of regenerated air 1.5m / sec. Dehumidifying rotor rotation speed Data of dehumidifying air at 3.5 rpm is shown in Fig. 6. In the figure, the horizontal axis represents the absolute humidity [g / kg] of the treated air TA at the inlet of the first-stage adsorption zone, and the vertical axis represents the dew point [° C] and the temperature [° C] of the supply air SA at the outlet of the second-stage adsorption zone.
An example of the data is shown on the next page.

EFFECTS OF THE INVENTION Since the present invention has the above-described configuration, it is not necessary to arrange two sorption rotors in parallel as in the conventional method to perform a two-step sorption operation, and a drive device, a casing, a seal, and a piping It is possible to obtain a gas in which the active gas in the process gas is sorbed and removed until the required low concentration is obtained by simply installing the above. For example, when the same moisture absorbent is used and the rotor pore size and thickness, and the air volume per unit time of the treated air and the regenerated air are the same, a conventional method yields an ultra-low dew point of -80 ° C or less. Dehumidification operation that requires two 500mm diameter rotors
It can be performed with one rotor having a diameter of 50 mm, the structure is simple and accordingly the cost can be reduced, and the power cost can be greatly saved, the installation area can be reduced, and the maintenance cost can be reduced.

In the dehumidification operation, when the temperature of the rotor is high in the dehumidification operation, the moisture absorption capacity of the rotor decreases. Therefore, the rotor portion after desorption / regeneration is precooled in the precooling zone 4 at a pre-cooled air PA, preferably an extremely low humidity. A part of the dehumidified air SA is pre-cooled and then dehumidified. Here, as the pre-cooled air PA, outside air, preferably outside air of low temperature and low humidity, may be partly added.

In the dehumidification operation, first, low-humidity air in the second-stage dehumidification zone 3, that is, air that has undergone a considerable dehumidification treatment in the first-stage dehumidification zone 2 is dehumidified to the required low dew point, and then the sorbed amount at that time is slightly reduced. Of the moist rotor portion may sorb a sufficient amount of moisture from the process air in the first stage dehumidification zone 2.

Next, in the regenerating operation, if the dehumidified air that has been used for pre-cooling and the temperature of which has been raised as a result is heated by the regeneration air heating heater 8 and used as the regeneration air RA, only the outside air is heated and used as the regeneration air. In comparison, its relative humidity is low, so the regeneration effect is great. Regeneration may be performed in one stage as shown in Example 1, but this is changed to two stages, and as in Examples 2 and 3, the second stage reproduction zone 11 and the first stage reproduction zone 5 are provided to provide two stages. If the desorption regeneration is carried out in the second stage regeneration zone, the considerably high temperature regeneration exhaust gas discharged from the first stage regeneration zone 5 is further discharged.
It can be used for regeneration in 11, saving heat energy. Further, when two kinds of sorbents are used in combination as in Example 2 above, the temperature is slightly low and the humidity is high at first, but the temperature and the dryness are sufficient for normal level regeneration. A sorbent, such as magnesium silicate aerogel, which can be desorbed and regenerated at a relatively low temperature, for example, 80 to 110 ° C. by the regeneration exhaust of the first stage regeneration zone, is used in the second stage regeneration zone 11
In the first stage regeneration zone 5, sorbents such as zeolites, which require high temperatures for regeneration, can be regenerated primarily using the exhaust from the precooling zone 4 at high temperature and low relative humidity. Example 1 in the case of one sorbent or in the case of the combined use of two or more sorbents having almost the same regeneration temperature
As shown in FIG. 1, the reproduction zone may be limited to one copy.

In the first and third embodiments (Figs. 1 and 4), the processing air is shown to flow from the bottom to the top, and the regeneration air is shown to flow from the top to the bottom in the rotor in the reverse direction. Can be selected as appropriate. However, in terms of utilization of waste heat, dehumidification efficiency is improved when the flows of the treated air and the regenerated air are reversed.

Further, looking at the flow of the regenerated air in the rotor, the temperature of the regenerated air is considerably lowered while passing through the regeneration zone as indicated by the line 5 in FIG. 7, and the regeneration capacity is rapidly weakened near the outlet. Therefore, as shown in FIG. 2, the reproduction zone is divided into a first-stage reproduction zone 5 and a second-stage reproduction zone 11,
When the flow of the regenerated air in both regeneration zones is reversed, the temperature drop of the regenerated air in each zone becomes as shown by the solid line 5 (RA ₁ ) and the chain line 11 (RA ₂ ) in Fig. 7, which shows the heating effect of both. When combined, the entrance (exit) to the exit (entrance)
Playback is performed substantially uniformly throughout the entire area without extremely decreasing until the end.

In the sorption process, for example, when one type of sorbent is used to dehumidify relatively humid air,
The cross-sectional area of the first-stage sorption zone 2 is wide, and the second-stage sorption zone 3
The cross-sectional area of the first stage is narrowed, and the treated air is first passed through the first-stage sorption zone 2 at a low speed to absorb almost all the moisture, and then the treated air with low humidity is fed into the second-stage sorption zone 3 at a high speed. By sorbing a small amount of moisture remaining in the through-process air,
Dry air can be efficiently obtained without using the cooler 10.

Further, as described in the third embodiment (FIGS. 4 to 5), the rotor 1
The lower part of the main component is a magnesium silicate aerogel, that is, an adsorbent having a normal dehumidifying performance and a relatively low desorption / regeneration temperature, and the upper part has a hygroscopic performance with respect to the air having a low humidity such as the magnesium silicate aerogel and zeolite. When it is used in combination with a hygroscopic agent that has an extremely high desorption / regeneration temperature and a relatively high temperature, when the treated air is fed from below in the dehumidification process, considerable moisture is adsorbed and removed by magnesium silicate aerogel in the lower part. After that, since the residual water vapor is further adsorbed mainly by zeolite or the like in the upper part, it is possible to further adsorb and remove the moisture in the air to an ultra-low dew point, and in the desorption process, when regenerated air is introduced from above, The temperature of the regeneration air gradually drops while passing through the small through holes of the rotor, but the desorption regeneration temperature is relatively high in the upper part due to the high temperature regeneration air. Zeolite or the like can be played slightly temperature decreased relatively low magnesium silicate erotic gel desorption regeneration temperature by regeneration air of the lower portion after playing, it can effectively utilize the regenerative heat energy.

In general, gas sorption by solid sorbents, including the case of dehumidification, becomes higher as the temperature becomes lower, and the higher the temperature becomes, the more difficult the sorption becomes and the desorption reaction tends to proceed. In the case of gas sorption, the same effect can be exhibited by selecting a sorbent or a combination thereof suitable for each sorption gas.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an example of the low-concentration gas sorption machine of the present invention, FIGS. 2 and 4 are explanatory views showing other examples of the low-concentration gas sorption machine of the present invention, and FIG. 2 and 4 are perspective views of the sector S used in the low concentration gas sorber, FIG. 5 is an explanatory view of the rotor 1 in FIG. 4, and FIG. 6 is dehumidification of the dehumidifier of the third embodiment. FIG. 7 is a graph showing the performance, and FIG. 7 is a graph showing the temperature distribution of the regeneration air in the regeneration zone. 1 to 4, 1 is a low-concentration gas sorption rotor, 2 is a first-stage sorption zone, 3 is a second-stage sorption zone, 4 is a pre-cooling zone, 5 and 11 are regeneration zones, 6, Reference numerals 7 and 9 are fans, and 8 and 12 are heaters for heating regenerated air.

Claims (6)

(57) [Claims] 1. A gas sorption rotor having a large number of small through holes extending from one end surface to the other end surface of a cylinder and having a gas sorbent on the surface of each of the small through holes. Each part is configured so as to sequentially act as a sorption zone of 2 or more parts, a precooling zone of 1 part, a regeneration zone of 1 part or more, and the sorption zones of 2 or more parts form a series of gas-containing gas flow passages. A low concentration gas sorber configured to form. 2. The low-concentration gas sorber according to claim 1, wherein the gas is water vapor and the gas sorber is a dehumidifier. 3. The low-concentration gas sorber according to claim 1 or 2, wherein the gas sorbent is a gas sorbent. 4. The low-concentration gas sorber according to claim 1 or 2, wherein the gas sorbent is a gas adsorbent. 5. A gas adsorbent having a normal gas adsorbing performance as a gas adsorbent and a gas adsorbent having an extremely high gas adsorbing performance for a gas having a low concentration of contained gas are used together. Low concentration gas sorption machine. 6. A gas adsorbent having ordinary gas adsorbing performance is silica erogel or a metal silicate erogel, and a gas adsorbent having extremely high gas adsorbing performance for a gas having a low gas concentration is zeolite. Low-concentration gas sorption machine according to claim 5.