JPH0673610B2 - Adsorption device for gas separation - Google Patents

Description

Description: FIELD OF THE INVENTION This invention uses an adsorbent, preferably activated carbon, for the adsorption of radioactive krypton and / or xenon, in which case the tube containing the adsorbent is thermally insulated. The present invention relates to an adsorption device for gas separation, which is vertically arranged in a closed container and has an adjacent heating device and refrigerant. The invention also provides an adsorption device suitable for the treatment of carbon dioxide and / or nitric oxide, and in some cases also for the separation of water, in which case zeolites are advantageously used as adsorbents. ) Concerning.

[Prior Art] In the case of an adsorber which is known from DE 3214825 DE and which is intended to separate krypton by activated carbon, not only the cooling of the adsorbent necessary for the adsorption but also the accumulation of krypton The heating of the adsorbent required for purging is also unsatisfactory due to the significantly uneven temperature distribution. This non-uniformity results in thermal stresses and thus constant fluctuating stresses. This is because gas separation using an adsorption device requires a continuous conversion between cooling and heating.

Special magazine "Kerntechnik", 1974, Volume 12,
In the fission gas separator described on pages 528 to 532, since the container is filled with liquid nitrogen that acts as a refrigerant, the adsorbent cartridge suspended on the container lid,
The area around the tube heater and level detector is washed. For desorption, the tube heater must first vaporize the nitrogen and the activated carbon trap must be heated to 300 ° C. by thermal radiation. This is very energy consuming and not easy from the point of view of the device. A rapid conversion between adsorption and desorption is practically impossible.

[Problems to be Solved by the Invention] The present invention achieves a uniform temperature distribution with a small cost of equipment, and as a result, frequent operation changes are possible due to small thermal stress, and even when the number of units is small, it is industrial. An object of the present invention is to provide an adsorption device that can be favorably used in production.

[Means for Solving the Problems] This object is based on the present invention. A refrigerant is contained in a pipe device that extends along almost the entire length of the adsorbent pipe, and a gas circulation device is arranged in the container. And the gas flow is distributed over the entire length of the heating device, cooling pipe and adsorbent pipe.

In the present invention, both the cooling device and the heating device are aligned as individual components to the adsorbent tube and are installed together with the adsorbent tube in the container. With such a configuration, it is possible to maintain a practically uniform temperature along the adsorbent tube with a very small temperature difference in the direction perpendicular to the adsorbent tube bundle. Since the heat exchange between the adsorbent tubes and the cooling or heating device is strongly carried out by the circulating gas, preferably helium, a uniform temperature distribution and, in addition, a significant reduction in energy consumption are achieved. The gas circulation rate is advantageously 100 times or more per hour.

The concentric serpentine of the cooling device can be oriented vertically parallel to the vertically extending tube bundle of the adsorbent tubes, while the heating device need only extend over a portion of the height of the tube bundle and the serpentine. Advantageously, a ventilator can be placed in the remaining space.
Since the gas circulation is driven by the fan, more rapid heat transfer is achieved.

Since the aerator is arranged behind the heating and cooling elements in the flow direction, a homogenization of the temperature of the simultaneously circulating gas stream in addition to gas transport is achieved before the gas stream enters the adsorbent tube bundle, The occurrence of veins with different temperatures is reliably prevented.

Further, when passing through the adsorbent tube bundle, a pressure loss of, for example, two times or more, or several times the pressure loss of the remaining flow path is generated.
The pressure drop in the gas circulation should be chosen. This achieves a substantially uniform inflow velocity of the adsorbent tube bundle, which prevents various thermal material stresses and sorption differences in the adsorbent.

The drive motor of the fan can advantageously be arranged outside the container so that it operates at normal temperatures. It is not necessary to dissipate the heat loss at that time via the cooling device. The drive motor can then be surrounded by a gas-tight capsule, which at the same time acts as a cooling jacket and is flanged to the container. This avoids heat loss along an axis that can be guided through the container wall.

In a particularly advantageous embodiment of the adsorption device according to the invention,
The tube bundle, the flexible tube and the heating device are connected to each other and are suspended in the container as a unit. The container is advantageously provided at the upper end with an opening of the same cross section as the internal space and is closed by a flanged lid. Through this opening the unit can be integrated as a whole and taken out again if necessary. As a special advantage, a relatively small pressure drop is obtained by incorporating all the necessary functional elements in the container, so that the temperature is remarkably homogenized with low energy consumption, for example a gas circulation rate of 1000 times per hour or more is realized. it can.

The adsorption device according to the invention can be advantageously adopted for various purposes due to its advantageous structural form and the resulting cost savings. However, the use in an installation with at least two branches in parallel is particularly advantageous, in which one adsorber acts as an adsorber and at the same time the other adsorber is regenerated. Although each adsorption device operates stepwise during such usage, the equipment can be continuously operated. At that time, the combined gas circulation (helium combined gas circulation) transfers the energy (heat quantity / cooling heat quantity) accumulated in the adsorption device from one branch to another branch arranged in parallel, thereby recovering heat. Energy use of formula is performed. Energy consumption by about 30 or
It can be reduced by 50%. Such uses are particularly suitable in nuclear technology, for example in the reprocessing of nuclear fuels in which the krypton and / or xenon nuclides are separated from the gas mixture and stored separately. However, it can accordingly be used particularly advantageously in the purification and / or drying of mixed gases by adsorption of nitric oxide, carbon dioxide and water.

Embodiments Next, the present invention will be described in detail with reference to the drawings showing a plurality of embodiments of the adsorption device according to the present invention.

The adsorption device 1 according to the invention comprises a container 2 having a metallic outer wall 3 and a heat insulating layer 4, the cross-section layer 4 being constructed as solid insulation or vacuum insulation. The container 2 has, for example, a diameter of 2 m and a height of 3 m. The upper side is configured as a lid 6 fixed by a flange joint 7. The opening closed by the lid as shown has the same cross section as the internal space 8 of the container 2.

Below the lid 6, a fixture 10 projects from the lid 6 into the internal space 8. The fixture 10 holds an adsorption unit, which is generally designated by 11, and comprises a tube bundle 12, a cooling device 9 and a heating device 14.

The tube bundle 12 consists of a number of vertically arranged tubes 16 which are arranged parallel to one another on an annular surface. The inner diameter of this ring is, for example, 1 m. Pipes 16 at the top and bottom are pipe end plates 17,
Ring plates 19, 20 which are fitted in 18 and which are inflated in a circle to form collecting chambers 21, 22 are fixed on the tube end plates. The tube 16 has, for example, a diameter of 35 mm and contains activated carbon having an apparent specific gravity of 0.45 kg / 1. The tubes are tightly packed so that the spacing between the tubes 16 is less than the tube diameter.

The cooling device 9 includes a flexible tube 13 inside the tube bundle 12. The flexible tube 13 can be formed in a single layer in a cylindrical shape. The end of the flexible pipe 13 is connected to external connecting pipes 27 and 28 led out from the container 2 via an inflow conduit 25 and an outflow conduit 26. The connecting pipe 28 leads to a refrigerator (not shown), by which liquid nitrogen as a secondary refrigerant can be introduced into the container internal space 8 in order to generate a temperature lower than -130 ° C. The flexible tube 29 has a diameter of 20 mm, for example. The spacing between the flexible tube 13 and the inner diameter of the tube bundle 12 is of similar size.

The heating device 14 is arranged in the center of the inner space 8 of the container, and thus inside the tube bundle 12 and the flexible tube 13. The heating device 14 comprises electric heating rods 30, which extend parallel to one another and vertically upwards from a lower support plate 31. The support plate 31 consists of one piece with the lower tube end plate 18 of the tube bundle 12. The support plate 31 holds a heating rod, and the heating rod is gathered inside the flexible tube 13 in an annular shape with the same interval as the thickness of the heating rod.

The height of the heating rod 30 is smaller than the height of the tube bundle 12 and the flexible tube 13.
Therefore, a space 35 is formed inside, and a ventilator 36 is arranged in this space 35. The ventilator 36 can also be arranged above the bundle of tubes and below the container lid. The ventilator 36 is a star-shaped holder
Mounted in cover 38 by 37. A drive shaft 39 is guided upward from the holder 37 through the container 2 to the drive motor 40, and the drive motor is fixed on the lid 6 outside the container 2. The electric motor 40 is surrounded by a gas-tight capsule 41, which is gas-tightly fixed on the lid 6 by a flange connection 42. The capsule 41 is configured as a double-walled cooling jacket 43 for dissipating the waste heat of the electric motor, and has a refrigerant inlet 43a and a refrigerant outlet 43b.

The internal space 8 of the container 2 contains, for example, helium having a pressure of 1 bar. Helium serves as a heat transfer medium and is circulated in the container interior 8 in the direction of arrow 44 by the fan 36. During circulation, the helium passes through the tube bundle 12 and is cooled by the flexible tube 13 or heated by the heating device 14. Circulation speed is 1000 per hour
More than once.

When the gas mixture to be purified is introduced into the tube bundle 12 via the connecting tubes 46, 47, the activated carbon in the tube 16 of the tube bundle 12 enhances the accumulation of dilute Gascriptin and xenon by cooling.
The purified gas is drawn out through gas outlets 50, 51 provided in front of or behind the plane of the drawing. Then, krypton and xenon can be expelled by heating the activated carbon with the heating device 14 after the accumulation. The heat of the heating device is likewise transferred to the pipe 16 by means of the fan 36.

FIG. 2 shows an adsorption facility 55 operating almost continuously in order to separate xenon and krypton from the fission gas produced during nuclear fuel reprocessing. The installation 55 comprises two identical systems 56, 57 which are connected in parallel with each other to an inlet 58 for the gas to be purified and an outlet 59 for the noble gas, while the purification 54 is indicated. A gas outlet is provided.

Both systems 56 and 57 have the same configuration and the precooler 6
With 0, 60 ', these precoolers can be separated by valves 61, 61'. Inlet 63 for carrier gas,
Lines 62, 62 'with 63' and valves 64, 64 'lead to adsorbers 66, 66' configured like the adsorber shown in FIG. Adsorption devices 66, 66 'are interconnected via valves 67, 67'. Adsorption device 66, 66 'is further ventilator 68
The ventilator 68 can be shut off by means of a valve 69. Therefore, by appropriate sequence control and feedback control, the equipment 55 can perform heating / cooling operation and heat exchange through the circuit 70 in opposite directions between the adsorbing devices 66 and 66 '.

The adsorbers 66, 66 'are followed by intercoolers 72, 72', which can be shut off via valves 73, 73 'and by-pass with valves 75, 75'. It is bridged by pipes 74 and 74 '.

Behind the intercoolers 72, 72 'is a second adsorption device 78, 78'.
Is provided. Between the adsorbers 78 and 78 'a valve 7
A circuit 62 is connected via 9, 79 'and a ventilator 80 having valves 81, 81' connected to the front and rear thereof, and this circuit serves as an adsorption device 78.
A heat exchange with 78 'can be performed.

Each line 56, 57 can be shut off at the end via valves 84, 84 '. A bypass line 86 with valves 87, 87 'in front of these valves,
86 'branches and the bypass lines 86, 86' lead to the precoolers 60, 60 '. A system that acts as an adsorber via line 86 (here
The gas purified in 56) is led to the outlet 54.

At the same time, the line 57 is regenerated. While continuously heating the adsorption devices 66 ', 78', these devices are supplied with a cleaning gas, such as helium, which is fed into the inlet 63 '. The cleaning gas flows through the adsorbers 66 ', 78', the intercooler 72 'being bypassed via the line 74'. Then, the rare gas is carried out by the cleaning gas through the outlet 59.

FIG. 3 shows an adsorption facility 90 that is operated almost continuously to separate water and nitrogen oxides from the solvent exhaust gas or the shielded concrete room exhaust gas generated during the nuclear fuel reprocessing. The equipment 90 can be connected as a pre-adsorbed adsorption system to the adsorption equipment 55 constructed according to FIG. 2 for noble gas separation, or used in closed circulation operation for purification of the atmosphere in a shielded concrete room. it can.

The installation comprises two identical systems 91, 92, which are connected in parallel with each other to an inlet 93 for the mixed gas to be purified and an outlet 94 for the purified mixed gas, while An inlet is provided for the cleaning gas used for regeneration shown at 95, and an outlet for the cleaning gas is provided at 96. The outlet 94 is optionally connected to the inlet 58 of the adsorption facility 55 shown in FIG.

The systems 91 and 92 have the same configuration and each have one adsorption device 97, 9
7 ', the structure of these adsorption devices corresponds to the adsorption device 1 shown in FIG. 1 or the adsorption device shown in FIG. 4 and described later. At that time, zeolite is used as an adsorbent.

From the inlet 93, the pipes 98 and 98 'pass through the valves 99 and 99' and the adsorption device 9
7 and 97 'and from there through valves 101 and 101' to outlet 94. Furthermore, the adsorption devices 97, 97 'are connected to the heating device 105 via lines 102, 102' with valves 103, 103 '.
A ventilator 106 is connected in front of the heating device 105, which ventilator can be shut off by means of a valve 107 and is connected to the cleaning gas inlet 95. It is connected via a line 110, 110 'with a valve 111, 111' to a cooler 113 and a subsequent cleaning gas outlet 96.

While one system (here, 91) is operating in the gas purification operation by adsorption, the valves 99 and 101 are opened and the gas flows through this adsorption system from the inlet 93 to the outlet 94. The heat of adsorption radiated at this time is released through the cooling device 9 shown in FIG. 1 and incorporated in the adsorption device 97, and the adsorbent filling section is maintained at a predetermined temperature of, for example, 10 ° C. Valve 10
3, 111 are closed. At the same time, the parallel system 92 is reproduced. For this purpose, the adsorption device 97 'is supplied with the cleaning gas taken in at the inlet 95 by the ventilator 106 and the heating device 105 while opening the valves 103' and 107. At that time, the adsorption device 97 'is heated to a regeneration temperature of, for example, 250 ° C. by the heating device 14 shown in FIG. After flowing out of the adsorption device 97 ', the cleaning gas is led to the cooler 113 via the opened valve 111' and the line 110 ',
It is then carried out via outlet 96 with the water and nitrogen oxides still present behind the cooler.

The outlet 96 can be connected to a process unit connected in series with the adsorption facility 90, in which desorbed nitric oxide is recycled.

The cleaning gas inlet 95 is connected to the outlet 54 of the adsorption facility 55 shown in FIG. 2 so that the cleaning gas supply of the adsorption facility 90 can be carried out particularly advantageously with the purified gas from the adsorption facility 55 shown in FIG.

FIG. 4 shows a tube bundle 12 different from the adsorption device shown in FIG.
An adsorption device 120 is shown, where 1 is not configured as a torus. The shape of the tube bundle 121 is configured as a square or rectangular portion of the tube bundle shown in FIG. A guiding device for guiding the heat carrier gas circulated in the container interior space 122.
123 is provided, which guide ensures a horizontal flow into the tube bundle 121 in the direction of the arrow 124.

The heat carrier medium circulated here is cooled by a cooling device 126, which consists of heat exchange consisting of finned tubes 127 which extend vertically parallel to the adsorbent tube bundle 121 and guide the refrigerant. Alternatively the heat carrier medium is an electric heating device 128.
The connecting wire is led out by the bushing 129.

The adsorbent tube bundle 121 again has a heating device 128 and a cooling device 127.
And together with the guide device 123 as a unit 130 suspended in a container 131. The unit 130 is held via a fixture fixed to the container lid 133 and a gas inflow / outflow conduit 132.

The adsorber container 131 is configured as a double-walled vacuum insulating container, and the container lid 133 is filled with a powdery inorganic insulating material 134. The adsorber 120 can advantageously be used for the purification of mixed gases in the case of small to medium volume flows of eg 50 m ³ / h. If a relatively large volume of adsorbent is required to purify a relatively large volumetric flow rate, the adsorbent should be in a tube with a square cross section as shown in the cross-section of FIG. 5, rather than in a cylindrical tube.
Can fit in 135. In this case, the long sides of the plurality of tubes 135 are arranged parallel to the gas flow. Before the gas stream hits the cooling device 126 and the heating device 128, these tubes are blown with gas on their long sides along the entire length of the tube.

FIG. 6 shows another embodiment of the adsorbent tube bundle 141,
An adsorber 140 is shown having the advantage of incorporating all functional elements such as heating 142, chillers 143 and gas circulation 144 inside a thermally insulated container 145.

A heat carrier medium such as helium or nitrogen is circulated in the vessel interior space 147 in the direction of arrow 146 by a fan 144,
At this time, the adsorbent tube bundle 141 flows under the action of the guide plate 148. The cooling device 143 is provided as a flexible tube that is concentrically guided around the tube bundle. The heating device 142 penetrates the container lid 149 from the outside in the form of an electric heating rod and is fixed to the lid by a flange 150.

The drive unit 151 of the ventilator 144 is attached to the lid 149 outside the container 145. The drive unit acts via the electromagnetic coupling 152. An electromagnetic coupling 152 fixed to the ventilator shaft 153 to prevent outward leakage through the ventilator shaft 153.
Half of the inside is mounted inside a gastight capsule 154,
The capsule is flanged to the container lid 149.

[Brief description of drawings]

1, 4, and 6 are longitudinal sectional views of different embodiments of the adsorption device according to the present invention, and FIG. 5 is a transverse sectional view of a modified example of the adsorption device shown in FIG. 4, and FIG. Fig. 3 is a pipeline diagram of an example of a rare gas separation facility that uses an adsorption device and that has two branches. Fig. 3 is a pipeline diagram of an example of a facility that recovers nitrogen oxide and moisture that has two branches that uses an adsorption device. Is. 2 …… Container 6 …… Container lid 8 …… Internal space 10 …… Fixing tool 11 …… Unit 12 …… Adsorbent tube (tube bundle) 13 …… Cooling tube (snake tube) 14 …… Heating device 35 …… Remaining Space 36 …… Ventilator 39 …… Ventilator shaft 40 …… Drive motor 41 …… Capsule 46, 47 …… Inflow line 50, 51 …… Outflow line 55, 59 …… Equipment 56, 57, 91, 92… … Branch 66, 66 ′, 97, 97 ′ …… Adsorption device 70 …… Heat exchange circuit

Claims (18)

[Claims] Claim: What is claimed is: 1. An adsorbent tube for gas separation, wherein a tube containing an adsorbent is vertically arranged in a thermally insulated container, and the adsorbent tube is provided with a heating device and a refrigerant adjacent to each other. A refrigerant is contained in a pipe device (13) extending over the entire length of the pipe near the (12), a gas circulation device (36) is arranged in the container (2), and the gas flow thereof is a heating device. (14) An adsorption device for gas separation, which extends over the entire lengths of a cooling pipe (13) and an adsorbent pipe (12). 2. The gas flow leaving the gas circulation device (36) first flows through the adsorbent pipe (12) and then through the heating device (14) and / or the cooling pipe (13). Item 1
The described device. 3. Device according to claim 1, characterized in that the adsorbent tube (12) has a rectangular cross section, the long sides of which are oriented in the direction of the gas flow. 4. The device according to claim 1, wherein the gas circulation rate is 100 times or more per hour. 5. An adsorbent tube forms a tube bundle (12) having an annular cross section, and a cylindrical flexible tube (13) is concentrically arranged in this tube bundle (12), and this flexible tube guides a refrigerant to form a tube bundle. 5. Device according to one of the claims 1 to 4, characterized in that an electric heating device (14) is arranged in the center of the (12) and / or the coil (13). 6. The pipe bundle (12) is supplied with circulating gas by horizontal inflow, and the pressure loss when passing through the pipe bundle (12) is at least twice the pressure loss of the remaining gas circulation passages. 6. The device of claim 5, wherein the device is. 7. The heating device (14) comprises a tube bundle (12) and a flexible tube (1).
3) extending only part of the height of the rest of the space (3
7. Device according to claim 6, characterized in that a ventilator (36) is arranged in 5). 8. Device according to claim 7, characterized in that a fan (36) is arranged in the container lid (6) just above the tube bundle (12). 9. Device according to claim 7 or 8, characterized in that the drive motor (40) of the fan (36) is arranged outside the container (2). 10. Device according to claim 9, characterized in that the drive motor (40) is surrounded by a gas-tight capsule (41) which is flanged to the container (2). 11. Device according to claim 10, characterized in that the capsule (41) is constructed with an intermediate space in the double wall, in which the refrigerant circulates. 12. An electromagnetic joint is arranged between the drive motor (40) and the fan (36), and the electromagnetic joint is formed by the fan shaft (3).
Device according to claim 9 or 10, characterized in that it acts via a capsule which surrounds 9) and is flanged to the container (2). 13. The tube bundle (12), the flexible tube (13) and the heating device (14) are connected to each other and are suspended in the container (2) as a unit (11). The apparatus according to any one of Items 1 to 12. 14. Device according to claim 13, characterized in that the unit (11) is suspended from a fixture (10) which projects into the internal space (8) of the container (2). 15. Device according to claim 14, characterized in that the unit (11) is suspended from the lid (6) via the inlet pipe (46, 47) and the outlet pipe line (50, 51). . 16. Device according to claim 1, characterized in that the internal space (8) of the container is connected to a pressure-regulating chamber arranged outside the container (2). 17. At least two branches in parallel (56, 57,
Used in equipment (56, 90) equipped with 91, 92) so that one adsorption device (66, 97) acts as an adsorption device and at the same time the other adsorption device (66 ', 97') is regenerated. Device according to one of claims 1 to 13, characterized in that 18. A heat exchange circuit (70) is provided between the adsorbers (66, 66 ', 97, 97') of the parallel branches (56, 57, 91, 92). 18. The device according to claim 17.