JPS647810B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an adsorbent, and more particularly to a heating regeneration gas supply apparatus for an adsorption tower, which regenerates an adsorbent by a heating regeneration method.

Adsorption methods that remove impurities using adsorbents such as silica gel, activated alumina, or zeolite are widely used in various fields because they can remove impurities at extremely low temperatures. In such adsorption methods, it is important to operate the plant while repeatedly regenerating the adsorbent. Therefore, many studies have been conducted on the regeneration of the adsorbent in the adsorption tower, and a typical example is pre-preparation. Examples include the shear swing method and the heat regeneration method.

However, the pressure swing method has the disadvantage that running costs (power amount) increase because the raw material is pressurized. Furthermore, the heating regeneration method requires cooling after heating, which increases the size of the apparatus. Moreover, due to the uneven temperature distribution within the adsorption tower that occurs during thermal regeneration, the temperature at the inlet side of the heated regeneration gas becomes higher, especially when using high temperature regeneration gas to shorten the regeneration time. There is a risk of thermal deterioration of the adsorbent. If a heat source is provided inside the column, it is possible to make the temperature distribution uniform and increase the regeneration rate, but in this case, the so-called wall effect causes pass-through and impurities are not sufficiently desorbed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a heated regeneration gas supply apparatus for an adsorption tower that can overcome the drawbacks of the prior art and efficiently regenerate adsorbent in a short time by uniform heating.

The present invention has a gas inlet for thermal regeneration of the adsorbent on one side and an outlet for the gas after the thermal regeneration containing the adsorbed substance removed from the adsorbent on the other side, A heated regeneration gas supply device for an adsorption tower, which has a raw material gas supply port to be treated on the exhaust port side of the finished gas, and has a treated raw material gas discharge port on the heated regeneration gas introduction port side, wherein the adsorption tower an outer cylinder is provided on the outer periphery of the cylinder, a supply source of heating regeneration gas is connected to the raw material gas supply port side of the gap between the outer cylinder and the adsorption tower, and the heating regeneration gas is connected to the other side of the gap between the heating and regeneration gas. It is characterized in that the outlet side of the heating regeneration gas sent from the supply source is connected to the heating regeneration gas inlet to the adsorption tower.

Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 1 is an explanatory diagram showing the direction of gas flow in a general adsorption step and heating regeneration step in an adsorption tower for dehumidifying moisture in the air, for example. During the adsorption (dehumidification) process, humid air 3 is pumped to the adsorbent 2 packed in the adsorption tower 1 in the lower part of the tower (A).
The dry air 4 is introduced from the upper side (B side) in the figure.
side). On the other hand, in the regeneration process, gas (heated air) 5 for heating regeneration is charged into the adsorption tower 1 from the B side in the figure, and after removing the adsorbed moisture of the adsorbent 2 and performing regeneration, the gas (heated air) 5 is It is discharged as humid air 6 from the side A in the figure. This is because an adsorption zone is formed on the inlet side of the adsorption tower 1 by moisture in the humid air 3 during the adsorption process, so the gas for heating and regeneration is passed in the opposite direction to facilitate desorption (dehumidification). be.

In the following embodiments of the present invention as well, the heating regeneration method is carried out by the flow of gas in this direction.

The adsorption tower in this example is shown in the second section
As shown in the figure, an outer cylinder 10 is provided with a gap 9 in the radial direction from the outer peripheral surface of an adsorption tower 8 containing an adsorbent 7 therein.
A supply source (not shown) of gas (heated air) 11 for heating regeneration is connected to the lower opening corresponding to the upper side (B side) of the adsorption tower 8 in the gap 9.
The upper opening corresponding to the side) is connected to the gas inlet for heating and regeneration of the adsorption tower 8.

In the adsorption tower of this embodiment, similarly to the adsorption tower shown in the first diagram, in the adsorption process, humid air 12 is introduced from below (side A) of the adsorption tower 8 as the raw material gas to be treated, and the treated raw material is Gas or dry air 13
is discharged from above (B side) of the adsorption tower 8.
In the regeneration process, the heated air 11 is first sent to the lower A side of the gap 9 between the adsorption tower 8 and the outer cylinder 10, and rises in this gap 9 while heating the outer peripheral wall of the adsorption tower 8 to the upper B side. is introduced into the adsorption tower, and after regenerating the adsorbent 7, the humid air 14 is introduced into the adsorption tower.
It is discharged from the lower side A of the adsorption tower 8 as a gas.

In the apparatus shown in Fig. 2, activated alumina is used as an adsorbent, and after saturated air is adsorbed onto the activated alumina, heated air 11 at 300°C is heated at SV=200h ^-1 (SV: space velocity, gas flow rate/column content). The distribution of the tower internal temperature T (°C) in the tower height H direction after 1 hour of introduction at
As shown in the figure.

As is clear from Figure 3, the distribution (curve) of the temperature inside the column in the example of the present invention is significantly improved compared to the distribution (curve) of the temperature inside the column in the conventional general adsorption tower shown in Figure 1. has been done.

In other words, as mentioned above, inside the adsorption tower, more water is generally adsorbed on the tower inlet side.
It is preferable to raise the heating temperature in this part, but in the case of conventional adsorption towers, the temperature is higher at the upper part of the tower, and as it goes towards the lower part, the temperature drops rapidly due to heat absorption. Therefore, the regeneration efficiency becomes extremely insufficient.

On the other hand, in the case of this embodiment, the heated air 11 for heating regeneration is first introduced from the part corresponding to the lower part of the adsorption tower in the gap 9 between the adsorption tower 8 and the outer cylinder 10, and the adsorption tower 8 is It rises while heating from the outer wall. Therefore, the lower part of the adsorption tower (side A), which has the most amount of water to be desorbed, is heated more strongly, and effective heating regeneration is performed with uniform temperature distribution.

After heating and regenerating for 2 hours in this way, air containing 2 and 4% V moisture was passed through each adsorption tower at SV = 1000 h ^-1 to check the regeneration state of the adsorbent. did. The breakthrough curve obtained in this experiment is shown in Figure 4 (the horizontal axis in the figure is the air volume V
The vertical axis shows the humidity content P (%V). As is clear from FIG. 4, the adsorption amount (curve) in the case of the example of the present invention is significantly larger (about 3 times) compared to the case (curve) of the conventional example shown in FIG. It has been shown that the regeneration efficiency is extremely high.

As described above, in the embodiment of the present invention, heated air 11 for heating and regeneration is introduced from below to above the outer peripheral surface of the adsorption tower 8 through the gap 9 between the adsorption tower 8 and its outer cylinder 10. Then, since the adsorption column is passed from above to below, the temperature distribution inside the column is improved and the regeneration efficiency can be significantly increased.

In the present invention, the temperature distribution can be further improved by adding a heating source, and FIG. 5 shows another embodiment of this kind. In the figure, adsorption tower 1
A heat source 19 that is heated by a power source 18 is provided in a gap 17 provided between the outer cylinder 16 and the outer cylinder 16 . Air 20 for heating and regeneration is in gap 1
7, it is heated by a hot wire 19 to a predetermined temperature for thermal regeneration, and then passes through the adsorption tower 15 from the top to the bottom in the figure.

The temperature distribution inside the column in this example is shown as a curve in FIG. 3 above. The breakthrough curve for the adsorbent regenerated in this apparatus is shown by the curve in FIG. As is clear from these figures, according to this example, the temperature distribution in the column during thermal regeneration of the adsorbent is further improved, and based on this, the regeneration efficiency is further improved.

FIG. 6 shows a flowchart of a dehumidification plant equipped with two adsorption towers according to the embodiment of the present invention shown in FIG. 2, which alternately perform adsorption and desorption processes.

An adsorption tower 21A shown on the left side of the figure is filled with an adsorbent 22A and has a gap 23A on its outer peripheral surface.
An outer cylinder 24A is provided via the outer cylinder 24A. Further, on the right side of the figure, similar adsorption towers are provided, each of which is designated by a corresponding reference numeral 21A to 24A.

Each adsorption tower 21A and 21B is provided with valves 25A, 26A and 27A, 28A, 2 for alternately switching between an adsorption process and a desorption process.
9A and valves 25B, 26B and valve 27B,
28B and 29B are provided, and valves 30A and 30 are further provided for supplying dry air from one adsorption tower during the adsorption process to the other adsorption tower during the desorption process.
B is provided. Valves 25A to 3 of each of these groups
0A and 25B to 30B are electromagnetically switched every 4 hours in this example by a timer (not shown) (valves shown in white in the figure are open, and valves shown in black are in the closed state).

In the illustrated state, the adsorption tower 21A on the left side is in the adsorption process, and moist air from the air pump NP is pumped into the valve 21A.
5A, and after dehumidifying it, the valve 26
Dry air DA is discharged through A. Valves 27A, 28A, and 29A for the desorption stroke are closed. On the other hand, the adsorption tower 21B on the right side is in the desorption process.
A part of the dry air from the left adsorption tower 21A during the adsorption process is heated by the heater HE supplied with power from the power source PW, and the air is heated in the gap 23 between the adsorption tower and the outer cylinder.
It is supplied to B. The heated air flows through this gap 23B.
The air is introduced into the adsorption tower 21B via the valve 28B, regenerates the adsorbent 22B, and then discharged as humid air MA via the valve 29B. After 4 hours, each valve is switched by a timer (not shown) to alternate between the adsorption process and the desorption process, and thereafter dehumidification is performed in the same manner.

In such a device, atmospheric air is introduced from the air pump NP at SV = 1000h ^-1 , and dry air heated by the heater HE is heated to a temperature of 300°C and SV =
It was supplied to the desorption process at 200 h ^-1 , regenerated for 2 hours, and cooled for the remaining 2 hours. The moisture content of the dry air dehumidified using the regenerated adsorbent obtained in this way is 2 ppm, compared to 100 ppm (this value increases with time) in the case of the conventional device used for comparison. It has shown a remarkable effect on Comparing the degree of regeneration that provides a predetermined amount of moisture, in the case of this embodiment, the time required for regeneration is significantly shortened compared to the conventional case.

Furthermore, when the adsorption tower used in the plant shown in Fig. 6 was replaced with the adsorption tower shown in Fig. 2 and equipped with the heating source shown in Fig. 5, even better results were obtained, and even better results were obtained under the same conditions. The water content was 1 to 2 ppm.

As described above, according to the present invention, excellent regeneration efficiency can be obtained in a short time by making the temperature distribution inside the adsorption tower uniform during the heating regeneration process of the adsorption tower.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the principle of the conventional heating regeneration system, Fig. 2 is an explanatory diagram showing the outline of the embodiment of the present invention,
3 and 4 are explanatory diagrams showing the operating characteristics of an embodiment of the present invention, FIG. 5 is an explanatory diagram showing an outline of another embodiment of the present invention, and FIG. 6 is an explanatory diagram showing the outline of another embodiment of the present invention. It is a flow diagram. 7... Adsorbent, 8... Adsorption tower, 9... Gap, 10... Outer cylinder, 11... Heated air, 14... Humid air.

Claims (1)

[Scope of Claims] 1. Having a gas inlet for thermal regeneration of the adsorbent on one side, and having an outlet for the heated regeneration-completed gas containing the adsorbed substance removed from the adsorbent on the other side, In a heated regeneration gas supply device for an adsorption tower, which has a raw material gas supply port to be treated on the exhaust port side of the heated and regenerated gas, and has a treated raw material gas discharge port on the heated regeneration gas inlet side, An outer cylinder is provided on the outer periphery of the adsorption tower, a supply source of heating regeneration gas is connected to the raw material gas supply port side of the gap between the outer cylinder and the adsorption tower, and the heating of the other side of the gap is performed. A heated regeneration gas supply device for an adsorption tower, characterized in that an outlet side of the heated regeneration gas sent from a regeneration gas supply source is connected to an inlet for the heated regeneration gas into the adsorption tower.