The present disclosure relates to a catalytic reactor including catalyst carriers inserted into respective channels defined by corrugated fins, and a method for making such a catalytic reactor.
Patent Document 1 describes a catalytic reactor in which the structure of a plate fin heat exchanger is used. This catalytic reactor is configured such that corrugated fins are arranged in respective passages defined by tube plates and brazed to constitute a core, and catalyst carriers are inserted into a plurality of channels defined by the corrugated fins, and is also configured such that a catalytic reaction is caused when a fluid flows through the channels. In the following description, the terms “catalytic reactor” and “core” will sometimes be used as synonyms.
PATENT DOCUMENT 1: Japanese Unexamined Patent Publication No. 2011-62618
PATENT DOCUMENT 2: Japanese Unexamined Patent Publication No. 2002-71288
In a plate fin heat exchanger, a side portion of a passage defined by tube plates facing each other is formed by a side bar arranged between the tube plates. Meanwhile, an end of a corrugated fin adjacent to the side bar may be defined by cutting halfway an upper or lower wall constituting a crest or trough of the corrugated fin. However, cutting at such a halfway point may cause the end portion of the corrugated fin to be caught in the gap between the tube plates and the side bar when the tube plates, the corrugated fin, and the side bar are stacked one upon the other and brazed together.
To solve this problem, the end of a corrugated fin does not have to be defined by cutting the upper or lower wall of the corrugated fin halfway but may be defined by cutting halfway a side wall connecting the crest and trough of the corrugated fin together as illustrated in
However, the present inventors discovered that if such a technique as the one described in Patent Document 2 was applied to a catalytic reactor, the following problem could occur. Specifically, as illustrated in
In view of the foregoing background, it is therefore an object of the present disclosure to avoid such a decline in the performance of a catalytic reactor, including catalyst carriers inserted into a plurality of channels defined by corrugated fins, by reliably securing a cross section, which is wide enough to allow the catalyst carrier to be inserted, for the channel formed between the end portion of each corrugated fin and the side bar.
An aspect of the present disclosure relates to a catalytic reactor. This catalytic reactor includes: tube plates configured to face each other in a first direction with a predetermined gap left between themselves and to define a passage where a fluid flows between themselves; a corrugated fin brazed in the passage defined by the tube plates and configured to partition the passage into a plurality of channels in a second direction orthogonal to the first direction; a side bar brazed between the tube plates facing each other, and adjacent to an end portion of the corrugated fin in the second direction so as to constitute a side wall of the passage; and catalyst carriers configured to be inserted into, and extend along, the plurality of channels defined by the corrugated fin.
The corrugated fin includes horizontal walls brazed to the tube plates facing each other in the first direction, and vertical walls arranged in the second direction at predetermined equal pitches corresponding to a dimension of the catalyst carriers. One end of the corrugated fin in the second direction is located halfway on one of the horizontal walls. One of the vertical walls of the corrugated fin that is adjacent to the side bar is arranged to provide a space where one of the catalyst carriers is insertable between the side bar and that vertical wall of the corrugated fin, and the end portion of the corrugated fin in the second direction is brazed to one of the tube plates between the side bar and that vertical wall of the corrugated fin.
According to this configuration, the end of a corrugated fin, including horizontal walls and vertical walls, in a second direction (i.e., the direction orthogonal to a first direction in which tube plates face each other) is located halfway on one of the horizontal walls.
One of the vertical walls of the corrugated fin that is adjacent to a side bar is arranged to provide a space where one of catalyst carriers is insertable between the side bar and that vertical wall of the corrugated fin.
Also, the end portion of the corrugated fin in the second direction is brazed to one of the tube plates between the side bar and that vertical wall of the corrugated fin. This prevents that end portion from being deformed and separated from the tube plate and distorting the cross-sectional shape of the channel defined between the side bar and that vertical wall of the corrugated fin.
Providing a sufficient space between the side bar and the vertical wall of the corrugated fin and preventing the cross-sectional shape of the channel from being distorted in combination allow for inserting the catalyst carrier as designed into the channel adjacent to the side bar. Thus, this catalytic reactor is allowed to achieve its expected performance with reliability, since the fluid passing through the channel constantly causes a catalytic reaction as expected.
Here, the interval between the side bar and that vertical wall of the corrugated fin may be set to be different from the predetermined pitches of the corrugated fin. In other words, the interval may be greater or less than the predetermined pitches. In this case, a catalyst carrier having a dimension corresponding to the interval is inserted into the channel defined between the side bar and that vertical wall of the corrugated fin. This catalyst carrier has different dimensions from any of the catalyst carriers inserted into the other channels.
Alternatively, the interval between the side bar and that vertical wall of the corrugated fin may be set to be equal to the predetermined pitches of the corrugated fin, and a catalyst carrier having the same dimensions as the catalyst carriers inserted between the vertical walls of the corrugated fin may be inserted between the side bar and that vertical wall of the corrugated fin.
According to such an embodiment, catalyst carriers having the same dimensions may be prepared and inserted into all of those channels. This helps reduce the manufacturing cost.
Another aspect of the present disclosure relates to a method for making a catalytic reactor. This method includes steps of: cutting, to a predetermined size, a corrugated fin, including horizontal walls and vertical walls, halfway on one of the horizontal walls; sandwiching the corrugated fin thus cut between tube plates in a direction in which the horizontal walls are in contact with the tube plates, arranging a side bar between the tube plates so that the tube plate is adjacent to one of the vertical walls in an end portion of the corrugated fin, and brazing the corrugated fin, the tube plates, and the side bar together; interposing, during the step of brazing, a spacer between the side bar and one of the vertical walls of the corrugated fin that is adjacent to the side bar to provide a predetermined space between the side bar and the vertical wall; and inserting, after the step of brazing, a catalyst carrier into a channel defined between the vertical walls of the corrugated fin, and also inserting another catalyst carrier into another channel which is defined between the side bar and that vertical wall of the corrugated fin and from which the spacer has been removed.
When tube plates, a corrugated fin, and a side bar are brazed together, a spacer is arranged between the side bar and an adjacent one of the vertical walls at an end portion of the corrugated fin, thereby reliably providing a predetermined interval there. In addition, the end portion of the corrugated fin is reliably prevented from being caught in the gap between the side bar and the tube plate. The spacer just needs to be a material that is not brazed to any of the side bar, corrugated fin, and tube plates in the brazing step, and for example, may be a slim ceramic bar.
After the tube plates, corrugated fin, and side bar have been brazed together in such a manner, the spacer is removed, and the catalyst carrier is inserted into the space from which the spacer has been removed (i.e., the channel defined by the side bar and that vertical wall of the corrugated fin). By using the spacer, the channel defined between the side bar and that vertical wall of the corrugated fin comes to have a cross section that is wide enough to allow the catalyst carrier to be inserted as described above. Thus, the spacer preferably has a cross section with substantially the same dimensions as the catalyst carrier. This ensures the insertion of the catalyst carrier. In this manner, the catalyst carriers having a predetermined shape are insertable into all of the channels. Consequently, a high-performance catalytic reactor is provided.
Here, the brazing step may be performed with the corrugated fin arranged such that an end of the corrugated fin is out of contact with the side bar. This reliably prevents the side bar from pressing the end portion of the corrugated fin under the influence of heat generated by brazing. As a result, the end portion of the corrugated fin (i.e., a portion of the horizontal wall in contact with the tube plate) is reliably brazed to the tube plate between the side bar and that vertical wall of the corrugated fin. This prevents the cross-sectional shape of the channel defined between the side bar and that vertical wall of the corrugated fin from being distorted, and ensures the insertion of the catalyst carrier having the predetermined shape into this channel. As a result, a high-performance catalytic reactor is provided.
As can be seen from the foregoing description, according to the catalytic reactor, the catalyst carrier is also insertable into the channel defined between the side bar and that vertical wall of the corrugated fin, thereby helping ensure the expected performance of the catalytic reactor. In addition, according to the method for making a catalytic reactor, the use of the spacer ensures the insertion of the catalyst carrier having a predetermined shape into the channel defined between the side bar and that vertical wall of the corrugated fin, thus allowing for making a high-performance catalytic reactor.
Embodiments of a catalytic reactor will now be described with reference to the drawings. Note that the following embodiments are preferred examples.
This catalytic reactor 1 includes a core 2 having basically the same structure as a plate fin heat exchanger. The core 2 includes a plurality of first passages 21 through which a first fluid flows, and a plurality of second passages 22 through which a second fluid flows. As partially illustrated in
As indicated by the solid arrows in
As illustrated in
As conceptually illustrated in
On the inflow surface 31 through which the first fluid flows into the core 2, an inflow header tank 41 is attached to the core 2 in order to distribute the first fluid into the channels of each first passage 21. An inflow nozzle 411 through which the first fluid flows in is attached to the inflow header tank 41. On the other hand, on the outflow surface 32 through which the first fluid flows out of the core 2, an outflow header tank 42 is attached to the core 2 in order to collect the first fluid that has passed through the channels of each first passage 21 and to allow the collected first fluid to flow out. An outflow nozzle 421 through which the first fluid flows out is attached to the outflow header tank 42. An inflow header tank 43 is attached to the inflow surface 33 through which the second fluid flows in, and an outflow header tank 44 is attached to the outflow surface 34 through which the second fluid flows out. The inflow header tank 43 and outflow header tank 44 for the second fluid respectively have the same configuration as the inflow header tank 41 and outflow header tank 42 for the first fluid. An inflow nozzle 431 and an outflow nozzle 441 are attached to the inflow header tank 43 and outflow header tank 44, respectively.
The first corrugated fin 211 in the first passage 21 is configured such that its upper and lower ends are orthogonal to the flow direction of the fluid (i.e., the X direction). A second corrugated fin 213 is arranged between this first corrugated fin 211 and the distributor fin 212.
The second corrugated fin 213 is a fin cut into a triangular shape just like the distributor fin 212, and is configured to partition the first passage 21 into a plurality of channels arranged in the Z direction just like the first corrugated fin 211. This second corrugated fin 213 is arranged to adjoin the first corrugated fin 211, thereby making the channels in the first passage 21 continuous in the X direction.
The first corrugated fin 221 in the second passage 22 is also configured such that its upper and lower ends are orthogonal to the flow direction of the fluid (i.e., the X direction), and although not shown in detail, a second corrugated fin 223 cut into a triangular shape is arranged between the first corrugated fin 221 and the distributor fin 222.
In addition, in the catalytic reactor 1, a catalyst carrier 215 is inserted into each channel in the first passages 21. As conceptually illustrated in
Next, it will be described in detail with reference to
The interval between the side bar 24 and the side wall 2113, 2213 of the first corrugated fin 211, 221 adjacent thereto (i.e., the distance in the Z direction between them) is set to be a predetermined one. This predetermined interval is the one allowing the insertion of the catalyst carrier 215, 225. Specifically, in the example shown in
Next, it will be described with reference to the drawings how to make a core 2 with such a configuration. First, although not shown, corrugated fins 211, 212, 213, 221, 222, and 223 are each formed by cutting a corrugated fin into a predetermined shape. At this time, each of the first corrugated fins 211, 221, in particular, defining a catalyst insertion region in which catalyst carriers 215, 225 are arranged, has its end defined by cutting an upper wall 2111, 2211 or a lower walls 2112, 2212 at a halfway point as described above. As will be described later, the halfway point of the upper wall 2111, 2211 or the lower wall 2112, 2212 just needs to be appropriately set to provide a predetermined interval between a side bar 24 and the side wall 2113, 2213 of the corrugated fin 211, 221 adjacent thereto and to prevent the end of the corrugated fin 211, 221 thus cut from contacting with the side bar 24.
Subsequently, tube plates 23 and side bars 24, which have been separately provided, and the corrugated fins 211, 212, 213, 221, 222, 223 are stacked one upon the other in a predetermined order. At this time, as illustrated in
The first corrugated fin 211, 221 is configured such that neither end thereof contacts with any side bar 24. The interval between the end of the first corrugated fin 211, 221 and the side bar 24 may be set to be an appropriate one.
Then, the tube plates 23, the side bars 24, and the corrugated fins 211, 212, 213, 221, 222, and 223 are brazed together. At this time, each end portion 2114, 2214 of the first corrugated fin 211, 221 is brazed to one of the tube plates 23 between its associated side bar 24 and the side wall 2113, 2213 of the first corrugated fin 211, 221 adjacent thereto. Thus, the core 2 is completed.
When the core 2 is completed, the spacers 216, 226 are removed, and catalyst carriers 215, 225 that have been separately provided are inserted into a channel defined between the side bar 24 and the side wall 2113, 2213 of the first corrugated fin 211, 221 adjacent thereto, and other channels defined between the side walls 2113, 2213 of the first corrugated fin 211, 221. Specifically, the catalyst carriers 215 in each first passage 21 are inserted one to one into the respective channels, which are open through a first fluid inflow surface 31 of the core 2 (i.e., the upper end face thereof), with the inflow surface 31 exposed before the attachment of a header tank 41. Likewise, the catalyst carriers 225 in each second passage 22 are inserted one to one into the respective channels, which are open through a second fluid inflow surface 33 of the core 2 (i.e., the lower end face thereof), with the inflow surface 33 exposed before the attachment of a header tank 43. In this manner, in the catalytic reactor 1 with this configuration, since the catalyst carriers 215, 225 are not fixed in the channels, the carriers are easily replaceable by removing the header tank 41, 43 attached to the core 2 to expose the inflow surfaces 31, 33 of the core 2.
After the insertion of the catalyst carriers 215 and 225, header tanks 41, 42, 43, and 44 are welded to the core 2. Thus, the catalytic reactor 1 is completed.
As can be seen, according to the catalytic reactor 1 with the above-described configuration, the end of the first corrugated fin 211, 221 in the Z direction, defining the catalyst insertion region, is defined by cutting the lower wall 2112, 2212 or the upper wall 2111, 2211 halfway, and a predetermined interval is left between the side bar 24 and the side wall 2113, 2213 of the corrugated fin 211, 221. Also, the end portion of the corrugated fin 211, 221 is brazed to the tube plate 23 between the side bar 24 and the side wall 2113, 2213 of the corrugated fin 211, 221 adjacent thereto. This enables the channel defined between the side bar 24 and the side wall 2113, 2213 of the corrugated fin 211, 221 to have a predetermined cross-sectional shape, thereby ensuring the insertion of the catalyst carrier 215, 225 into this channel. Thus, the catalyst carriers 215, 225 having a predetermined shape are inserted into all of the channels of the core 2. Consequently, the fluid passing through the core 2 is allowed to cause catalytic reactions reliably, thereby ensuring good performance for the catalytic reactor 1.
By using the spacer 216, 226 while making the core 2 by brazing, a predetermined interval is reliably provided between the side bar 24 and the side wall 2113, 2213 of the first corrugated fin 211, 221 adjacent thereto. In addition, the end portion 2114, 2214 of the first corrugated fin 211, 221 is reliably prevented from being caught in the gap between the side bar 24 and the tube plate 23.
Furthermore, since the end of the first corrugated fin 211, 221 is kept out of contact with the side bar 24 during brazing, the side bar 24 is reliably prevented from pressing the end portion 2114, 2214 of the first corrugated fin 211, 221 under the influence of heat. As a result, the end portion 2114, 2214 of the first corrugated fin 211, 221 is reliably brazed to the tube plate 23 between the side bar 24 and the side wall 2113, 2213 of the first corrugated fin 211, 221.
In this case, as long as the interval between the side bar 24 and the side wall 2113, 2213 of the first corrugated fin 211, 221 adjacent thereto is greater than or equal to a predetermined one, the catalyst carrier 215, 225 is insertable into the channel between them. However, if the interval is too wide, the strength of the core 2 will decrease, which is not beneficial. Specifically, the side walls 2113, 2213 of the first corrugated fin 211, 221, which are spaced at predetermined pitches in the Z direction and extend to connect the tube plates 23, 23 together in the stacking direction, function as members with a strength high enough to withstand the internal and external pressures in the core 2. For this reason, if the side wall 2113, 2213 of the first corrugated fin 211, 221 adjacent to the side bar 24 is significantly spaced from the side bar 24, the strength will decrease in this region.
Suppose while the interval between the side bar 24 and the side wall 2113, 2213 of the first corrugated fin 211, 221 adjacent thereto is increased, the cross-sectional area of the catalyst carrier 215 inserted between them decreases. In that case, the channel resistance of that channel becomes lower than that of any other channel. Such a difference in channel resistance between the channels of the core 2 causes a non-uniform flow, i.e., a situation where the flow rate of some of the channels becomes higher than that of the others. This may result in a decline in the performance of the catalytic reactor 1.
Thus, it is recommended that the interval between the side bar 24 and the side wall 2113, 2213 of the corrugated fin 211 be set within the range in which the strength of core 2 does not decrease, and be set according to the dimension of the catalyst carrier 215, 225 inserted into the channel between them. For example, the interval between the side bar 24 and the side wall 2113, 2213 of the first corrugated fin 211, 221 adjacent thereto may be set to be equal to the pitch between the side walls 2113, 2213 of the corrugated fin 211, 221 as illustrated in
Note that in some cases, no catalyst carriers 225 are inserted into the second passage 22, depending on the application of the catalytic reactor 1.
As can be seen from the foregoing description, the catalytic reactor of the present disclosure is useful as a catalytic reactor in various processes, because a catalyst carrier is reliably inserted into a channel defined between a side bar and a vertical wall of a corrugated fin to provide a high-performance catalytic reactor.
1 Catalytic Reactor
21 First Passage
211 First Corrugated Fin
2111 Upper Wall (Horizontal Wall)
2112 Lower Wall (Horizontal Wall)
2113 Side Wall (Vertical Wall)
2114 End Portion (of Corrugated Fin)
215 Catalyst Carrier
216 Spacer
22 Second Passage
221 First Corrugated Fin
2211 Upper Wall (Horizontal Wall)
2212 Lower Wall (Horizontal Wall)
2213 Side Wall (Vertical Wall)
2214 End Portion (of Corrugated Fin)
225 Catalyst Carrier
226 Spacer
23 Tube Plate
24 Side Bar
Number | Date | Country | Kind |
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2013-033775 | Feb 2013 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2014/000824 | 2/18/2014 | WO | 00 |