JPS63294922A - Structure of adsorption tower in psa-type adsorbing method - Google Patents

Abstract

PURPOSE:To reduce purging loss by dividing the inside of an adsorption tower into two parts with a partition plate or a double-pipe structure, and providing fins to the partition plate or the inner pipe, and providing the outlet and inlet nozzles of gas to the top side of the tower and an installation side respectively. CONSTITUTION:An adsorption tower 1 is divided into two parts with a partition plate 2 and the bottom part of the tower is opened and an adsorbent 3 is closely packed excepting the vicinities of an inlet nozzle 4 of gas, an outlet nozzle 5 of gas and gas diffusers 6. The rodlike fins 7 are fitted to the partition plate 2 and heat transfer effect is raised and the temp. distribution of a packed layer is eliminated. Dead space is made small by the structure of such the adsorption tower as this and purging loss is reduced. A double-pipe structure can be adopted instead of the partition plate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to gas separation by a PSA adsorption method, and particularly to an adsorption tower structure suitable for reducing dead space.

[Conventional technology]

In conventional equipment, gas is supplied from the bottom (or top) of the column, and the product is extracted from the top (or bottom). In this case, supports are attached to support the adsorbent, especially on the bottom side of the tower, which creates a considerable dead space, causing a large purge loss. In addition, as the column diameter increases, heat absorption and desorption heat accumulates, and the temperature at the bottom of the column decreases and desorption performance decreases, while the temperature rises at the top of the column and adsorption performance decreases, leading to a decrease in overall performance. It was waking up.

Note that related devices of this type include, for example,
JP-A-56-163753, JP-A-57-10722
Examples include No. 5.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology does not take into consideration the reduction of purge loss, which is a problem with the PSA adsorption method, and has the problem of placing a load on the vacuum pump and blower (increasing the M unit and cost).

In addition, as the column diameter increases, the temperature distribution in the packed bed increases, and there are few measures to eliminate this progress distribution, resulting in a decrease in performance.

The purpose of this invention is to reduce purge loss, eliminate temperature distribution in the packed bed, and eliminate filler support and the like.

[Means for solving problems]

The above objective can be achieved by dividing the inside of the adsorption tower into two parts using a partition plate or double pipe structure, installing fins on the partition plate or inner pipe, and installing gas outlet and inlet nozzles on the top side of each tower. nru.

[For production]

The partition plate or inner tube within the adsorption tower divides the adsorption tower into two parts, allowing gas to be supplied and discharged at the top of the tower, and also serves as a heat transfer plate and a gas distribution plate. Therefore, by attaching, for example, fins to these, the heat transfer effect and gas dispersion effect are further improved.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. Figure 1 is a vertical cross-sectional view of the adsorption tower in PSA adsorption, Figure 2
The figure shows a cross-sectional view taken along the line A-A in FIG. 1, FIG. 3 shows a detailed view of the gas distributor, and FIG. 4 shows a detailed view of the gas distribution plate. In the figure, an adsorption tower 1 is divided into two at the center by a partition plate 2, and the bottom of the tower is open (not partitioned). The adsorbent 3 is densely packed except in the vicinity of the gas inlet/outlet nozzle (gas inlet nozzle 4, gas outlet nozzle 5) and the gas distributor 6. The partition plate 2 is thin (except for the space).
It's good. Further, a type of rod-shaped fin 7 is attached to the partition plate 2 to improve the heat transfer effect and the gas dispersion effect. Furthermore, a dispersion plate 8 is attached to the opening at the bottom of the column to prevent the gas from passing through. In addition,
The nozzle 9 at the bottom of the column is an adsorbent outlet, and the nozzle 10 at the top of the column is an adsorbent inlet. The initial height of the adsorbent 3 is set to be 1.5 m at maximum here since PSA cannot perform high-pitched operation due to unsteady operation and is limited to a maximum of 3 m. The raw material air (gas) is sent to the adsorption tower from the gas inlet nozzle 4! The gas is supplied under pressure into the adsorbent 3, is uniformly dispersed by the gas distributor 6 (see FIG. 3), and passes through the adsorbent 3. At this time, H2O1N in the air (gas)
2 (adsorbed substance) is adsorbed by the adsorbent 3, and 02 (product gas) is gradually concentrated to become a product gas of about 90% concentration at the outlet nozzle 5.

On the other hand, regeneration of the adsorption tower 1 (desorption and removal of adsorbed H2O and N2 (adsorbed substances)) was carried out under reduced pressure.
, N2 (adsorbed substance) is discharged to the outside of the adsorption tower 1 from the gas inlet nozzle 4 (at this time, the gas outlet nozzle 5 is closed).

During adsorption and regeneration, the larger the dead space inside the adsorption tower, the more purge loss occurs due to pressure changes, resulting in an increase in raw material gas and exhaust gas. Costs and basic units will increase. Here, when we compared the purge loss between the conventional adsorption tower and the present adsorption tower 1, we found that on the conventional basis, the adsorption pressure was 1.5 ata, the degassation pressure was 350 Torr (0.48 ata), the switching cycle was 1 minute, and the feed air (gas) was 10 ,00ONm”/H,
Adsorption tower diameter 3m.

When calculated as a 2:1 elliptical mirror, the purge loss is 15 or more of the feed air (gas), whereas the purge loss of the adsorption tower 1 according to this embodiment (with the same operating conditions and 100 g of the disperser 6)
It was found that when the adsorbent 3 was filled to below 0 and the column diameter was 4.2 m and a 10% flat type mirror was used, the amount was 5% or less. Comparing No. 20 in terms of raw material air (gas) amount, it was confirmed that the amount was 91% or less compared to conventional methods.

In addition, in this series of operations, adsorption is an exothermic reaction and desorption is an endothermic reaction, and due to heat transfer by the gas flow, the adsorbent humidity on the gas inlet side decreases and the adsorbent humidity on the gas outlet side increases. , the low temperature part (gas inlet nozzle 4 side absorbent 3) and the high temperature part (gas outlet nozzle 5 side absorbent 3) are adjacent to each other with a partition plate 2, and the rod-shaped fins 7 further reduce the temperature difference. It became possible to make it smaller. By the way,
In the conventional method, in this class (1o, ooo Ni/H raw air (gas) humidity 20°C), the temperature difference (axial temperature difference) is below 10°C at the bottom of the column and above 30°C at the top. 2
In this example, the temperature was 0°C or higher.

The difference in temperature (between the gas inlet and outlet sides) is now 10°C or less, making it possible to significantly reduce performance deterioration due to temperature.

Historically, in this embodiment, it is also possible to alleviate the uneven flow of gas flowing through the adsorbent 3 by the fractional effect (see Fig. 4) by using the rod-shaped fins 7 to increase the heat transfer effect. It is now possible to improve the effectiveness of 3.

Next, as another embodiment of the present invention, one having a double pipe structure will be described with reference to FIGS. 5 to 158.

FIG. 5 is a vertical sectional view of an adsorption tower having a double pipe structure, FIGS. 6 and 7 are detailed views of the gas distributor, and FIG. 8 is a detailed view of the dispersion plate. In the figure, an adsorption tower 11 is partitioned by an inner pipe 12.
It is divided into two sections (the cross-sectional areas of the inner tube 12 and the outer tube are equally divided), and the bottom of the column is open. The adsorbent 13 is inserted into the gas inlet nozzle 14. It is densely packed except around the gas outlet nozzle 15 and the gas distributor 16,17. Rod-shaped fins 18 are attached to the inner and outer surfaces of the inner tube, and a dispersion plate 19 is further installed inside the bottom of the column. In the above configuration, the function of the present adsorption tower is the same as that explained in Figs. S1 to 4. However, the shapes of the gas distributors 16 and 17 and the distribution plate 19 are different. Although the reduction in purge loss is almost the same as in the previous example, the present adsorption tower 11 has further improved the uniformity of the 5 m degree distribution.

According to this embodiment, it is possible to reduce the purge loss and to reduce the degree of separation in the adsorption towers 1 and 11, so that the effect of maintaining performance can be expected.

〔Effect of the invention〕

According to the present invention, since the purge loss of the PEA type adsorption tower can be reduced, the load on the vacuum pump and blower can be reduced, and there is an effect of reducing the basic unit and cost.

Furthermore, since the moisture distribution within the adsorption tower can be made smaller, it has the effect of alleviating performance deterioration. Fig. 1 is a vertical cross-sectional view of an adsorption tower that does not include an embodiment of the present invention, and Fig. 2 is a cross-sectional view of A in Fig. 1. -A line sectional view, Figure 3 is a detailed view of the gas distributor in Figure 141, Figure 4 is a detailed view of the dispersion plate in Figure 1, and Figure 5 is a longitudinal cross-section of an adsorption tower showing another embodiment of the present invention. 6 and 7 are detailed views of the gas distributor shown in FIG. 5, and FIG. 8 is a detailed view of the distribution plate shown in FIG. 5.

l...Adsorption tower, 2...Partition plate, 3...
...Adsorbent, 4...Gas inlet nozzle, 5.
... Gas outlet nozzle, 6 ... Gas distributor, 7 ... Bar-shaped coin, 8 ...'' Dispersion plate,
11...Adsorption tower, tube...Inner pipe, 13.
...Adsorbent, Fig. 11/--In-house 5---Fj output rouletter--/Thrui Fig. 3 Fig. A4

Claims (1)

[Claims] 1. In gas separation by PSA adsorption method, a partition member that communicates only with the bottom of the tower is installed in the adsorption tower, fins are provided on both sides of the partition member, and an inlet disperser is provided on one of the tops of the tower. PSA characterized in that the other side is provided with an outlet disperser
Adsorption tower structure in formula adsorption method. 2. The adsorption tower structure in the PSA adsorption method according to claim 1, characterized in that the partition member is a partition plate. 3. The adsorption tower structure in the PSA adsorption method according to claim 1, characterized in that the partition member is an inner tube. 4. The adsorption tower structure in the PSA adsorption method according to claim 1, characterized in that a dispersion plate is provided at the bottom of the partition member.