FI118826B - The heat recovery tower - Google Patents

Abstract

The invention relates to a heat recovery tower for recovering heat energy from the gas generated in an industrial plant. The-heat recovery tower according to the invention is characterized in that it comprises a number of units that are arranged one on top of the other and detachably connected to each other, with at least two of them having been selected from: bottom basin, air/air-heat exchanger unit, scrubber unit, and air/water-heat exchanger unit. The invention also relates to a unit designated to be operating as a part of a heat recovery tower as well as a method for constructing a heat recovery tower for recovering the heat energy from the gas generated in an industrial plant.

Description

Ή 8826

HEAT RECOVERY TOWER

VÄRMEÄTERVINNINGSTORN

The invention relates to a heat-recovery unit 5 according to the preamble of independent claim 1 for at least partial recovery of the heat energy contained in the industrial air or other gas. Tom has at least one or more heat exchangers and other equipment needed in the process.

Many industrial processes generate enormous amounts of thermal energy which, for economic reasons, needs to be recovered where possible and used for other processes or otherwise. Many processes, especially the wood processing industry and downstream processing, produce moist and hot gases and vapors with significant amounts of water and often other substances. The heat recovery of such gases and gas volumes requires large-scale equipment which occupies quite a lot of the factory floor space. For example, in dryers used in papermaking 15, warm damp air is led along the pipelines to a fan with a high volume of heat exchanger, and only at the end of the process is the medium treated to the tower portion where the treated gas is vented to the roof of the building.

WO 98/56986 discloses a heat recovery apparatus with different temperatures! 1]: 20 exhaust air streams can be treated separately in the same heat recovery apparatus without mixing. US 4,591,462 again discloses an arrangement in which the heat exchange units are secured by means that melt when burned: and thus allow the heat exchange units to fall out of the fire area. EP 371 475, FR 276 6264, JP 60232491 and JP 9042863 disclose the state of the art in general.

GB 1 220 885 discloses an evaporative condenser. However, the publication does not

air / air heat exchangers or washer blocks are not shown. In US

m ·]. No. 4,774,033 discloses a tom structure for a gas-liquid interaction. According to an embodiment of the · ·· * shown, the structure has a bottom-up water collection chamber 30 (160), an interaction unit (18), a washer unit (130) and a droplet separator • 1 ·· (150) (column 14, lines 3-25). Thus, air / air heat exchangers and the first washer block are not disclosed.

2 118826

FR 125 3765 discloses a cooling tom for cooling liquids by evaporation. There are no air / air heat exchangers or washer blocks. GB 2 365 956 again discloses a device for cooling a liquid. Again, this unit does not have air / air heat exchangers or washer blocks.

It is an object of the invention to provide a heat recovery tomato which has a significantly lower floor space requirement than previous similarly efficient arrangements, whereby the total area of new buildings may be smaller than with conventional technology. It is also an object of the invention to provide a heat recovery tomato which is of such a small floor area that several such towers can be placed close to the origin of air or gas, thus avoiding long and large diameter pipelines, which are expensive and in many respects cumbersome. It is also an object of the invention to achieve a short installation time, in which case, for example, in the case of new plant projects in an old plant, the downtime in this regard is short. A further purpose is also to simplify the construction of the foundation, since such a 15 tower only needs a rather small but even stronger foundation to distribute the weight over a relatively small area. Another object of the invention is to simplify transportation. Since most of the practical applications of the tower of the invention are intended to be made suitable for road transport, the disadvantages of oversized transportation will not be apparent. For overseas destinations, standard 20-sea containers can be used, which is significantly inexpensive for special transports. pared. At the factory, the installation is to be done without the so-called. hauling, ie / using a larger mobile crane, units overlapping their installation location in the • • ♦; * roof opening of the factory. It is a further object of the invention to provide a sealing structure which in practice has a tight seal and a long-lasting sealing structure, thus not having the usual disadvantages - poor sealing capability of the flat seal in a flange assembled by two units with lu-V * * [[: usually leaks and stripes on the outside. The object of the invention is generally to avoid the use of bolts in outwardly visible structures as far as possible. a lot because bolted joints have known disadvantages. Purpose of the invention. 30 illustrates a structure that can be used to retrofit old plants so that the heat recovery efficiency and / or heat recovery capacity, respectively, * * ** "increases significantly compared to previous equipment, usually 5 to 15%, even more.

*: **: It is also a further object of the invention to provide a heat recovery unit which is uniform and clear, which is also simple and clear in piping, and which is easy and hassle-free to maintain. A further object of the invention is to avoid the use of undesirable substances such as sealant silicone pulp. It is also intended to provide a low-cost heat recovery tube that can be industrially manufactured in series, thereby achieving the benefits of the sax. It is a further object of the invention to provide a heat recovery tomato which is so modular that the desired number of units can be superimposed to achieve the desired function, efficiency and height for each operating state.

The object of the invention is achieved as disclosed in independent claim 1 and other claims. In the industrial plant, heat recovery units are generally used for at least partial recovery of the thermal energy contained in the warm air or other gas produced. The tom includes at least one or more heat exchangers 10 and at least one separating device for separating water from the moist air or vapor passing through the heat recovery tomato. If the equipment of the heat recovery tomato comprises a plurality of stackable units connected to the lower and upper units by means of the guiding means, so that during the installation step the unit is positioned by its guiding means 15 and its unit is lowered by your guiding elements, is quite quick to install at the installation site in its final form. The guiding members and their counterparts place the layers quickly and accurately as needed for the design.

20 If at least most of the superimposed units have at least • equal horizontal dimensions and shapes, they can be transported • over two, up to three overlaps, eg on a pallet or in a transport container, saving even during transport. . In the manufacturing process, ····· at the factory, the savings are due to the fact that one can make, for example, welding jig single junction ropes, since all come in the same tower. The ropes are of uniform cross-sectional shape and size.

* »• Il

If the heat recovery section has a horizontal cross-sectional appearance that is at least approximately rectangular, units of different power may be formed, in particular by choosing the longer side of the rectangle in high power single-. ·); 30 ropes quite large in relation to the other side. For example, if the shorter side is, for example, about 2.45 · ··] m long that fits inside the shipping container, the longer side may be, for example, less than 6 m, making it suitable for a 20-foot shipping container. Larger fits in 30 or 40 foot sea containers.

• ♦ • · i ♦ Il

If at least the majority of said superimposed units each form an entire layer of heat recovery tom, one complete unit manufactured from the 4 118826 units will provide one complete layer for on-site installation into a single layer. This is also a very strong structure because it is a uniform, closed ring. The structure can also easily provide a fairly accurate dimension.

If the outer wall plates of the layer forming unit are connected to each other by only 5 welding joints, bolt joints and their problems are completely avoided - sealing difficulties, tightness problems and appearance problems in the event of leakage. The welding joint is also strong and beautiful and simple compared to flanged seams

If the lower and upper layer unit are locked together by two or more so-lips or similar locking members at the guiding members, a very simple and quick connection locking structure is obtained. Opening is also easy if such an operation sometimes needs to be performed. Such a locking structure is also cheap to manufacture.

If a seal is used between the lower and upper layers which is compressed only by a selected distance when the upper unit is lowered into place on the lower unit, a sealing solution is obtained in which the seal function is ideal.

Compression takes place due to proper design and fabrication and no excessive compression can occur. In such cases, even the so-called. sealant or additives such as, for example, silicone pulp which has many known disadvantages.

It is recommended that said seal comprises at least two ridges in the transverse direction of the seal. In this case, at least the two sealing points are obtained, in which case leakage of the seal is quite unlikely.

• · • * · • M • ·. ···. If the lowest unit of the heat recovery tomato includes adjustable support legs that allow the heat recovery tomato to be adjusted as horizontally as possible, it provides a very easy and quick installation of the bottom part of the tomato structure, which can be easily mounted horizontally in both • • * ··· * you. In this case, even the foundation may be at least somewhat uneven and there is no harm in doing so.

• · 30 If the outer surfaces of the heat recovery tomato have stiffeners on which the guiding members of the upper unit are supported, a structure is obtained in which the stiffeners function not only as traditional stiffening components but also as interlayer, greatly facilitating and accelerating alignment.

5 118826

If the heat recovery unit includes at least one treatment level at a height above the floor, maintenance and repairs can be done safely and quickly from the treatment level without the use of separate structures or lifting baskets, which may not even work in the immediate vicinity of the heat recovery unit.

5 If at least one of the maintenance levels of the heat recovery tomato is supported by brackets at the stiffeners on the outside of the tower, the design of the maintenance level is clear, while providing a strong and stable attachment.

If the treatment platform bracket is secured to at least and preferably with only one bolt or the like in said stiffener, the installation and removal of the treatment platform is a 10 very quick operation.

If the heat recovery unit extends through the opening of the roof of the room above the ceiling, the floor space can be utilized efficiently, since a large number of units are located in the upper part of the room, which is generally poorly utilized. It is important that the outlet is provided on the roof and through it without special staging of the open air.

If the units of the heat recovery tomato include at least a basin, at least one heat exchanger and a scrubber device, a reattachment according to the invention can provide a convenient and functional but floor space-saving heat recovery tomato. Generally, the heat recovery tomato also includes one or more extensions, a silencer and a reducer with exhaust pipes.

• »S • · · · · · · · The invention will now be described in more detail with reference to the accompanying drawing, in which: - Figure 1 schematically illustrates a known and typical heat recovery apparatus ····· in a three-dimensional direction: - Figure 2 schematically shows a heat recovery apparatus according to the invention # · v *. Fig. 3 is a schematic exploded view of the heat recovery and .. ^ exhaust air blower of Fig. 2 in a three-dimensional direction, - Fig. Fig. 5a schematically illustrates a cross-sectional joint structure between the blocks in a partially cross-sectional view ·: ··· 30 - Fig. 5b schematically shows the structure of Fig. 5a joined together .. * with gaskets, • · \ "- Fig. 6 schematically shows a lower section Fig. 7 schematically shows the so-called AHR heat recovery block during the replacement of the honeycomb plate, and - Fig. 8 schematically shows the attachment of the treatment level to the side reinforcement profile of the heat recovery tom block.

5

In Figure 1 of the drawing, reference numeral 1 denotes a known heat recovery apparatus for recovering energy from air or gas, which is usually treated at least several cubic meters per second and generally tens of cubic meters per second in large units. The medium to be treated is introduced into the apparatus in a large tube shown by arrow 2, to a pretreatment apparatus 3, which typically has filters, water separation apparatus, and at least one heat exchanger for heating the medium with a fluid flow, e.g. Reference numeral 4 denotes an electric motor driven fan which blows air out of the apparatus. The heat exchanger 5 recovers the heat and finally the gas is blown up through the roof of the factory line which extends in the direction of the arrow 6 sufficiently high. The equipment is based on steel tube racks 7 and 8 standing on the floor. The fan 4 and the large pipes 2 and 3 are also supported from the floor. Thus, the floor has numerous bases, usually about ten, for such a heat recovery apparatus 1 over a wide area. In some previous solutions, the fan has been located on the roof of the factory to suck air through the system.

The heat recovery tomato 9 according to the invention shown in Figure 2 is mounted on the floor 10 of the factory and the tower 9 extends through the roof 11 of the factory. Usually the floor 10 and the ceiling: * ·. * 25 11 has a spacing of 5 - 10 m but it can be more, even more than 12 m. Heat recovery- * «. · **, totomi 9 is rectangular in horizontal cross section and assembled from modular units , sections made of sheet steel, most often stainless or stainless steel by welding. Blocks are available for different applications and sizes to achieve the desired performance. Tomato widths can be, for example, 1.70 m, 2.05 m and 2.45 m, whereby the widest of them can be carried by conventional means of transport, such as road transport or sea containers. *: * ·; The length of the modules can be constant, e.g. 4.20 m, so there are no transport problems in this respect too, however 4.20 m is already quite *, "large for many applications. Height can also vary, usually between 0.50 - 1 , 50 m. The transport • · t * · #i 35 can sometimes be overlapped by up to three blocks, if the transport space permits, and it is clear that the performance of the block is at least approximately directly proportional to the horizontal cross-sectional area of the block. Of course, there is no block spacing in Figure 2. For clarity, the heat recovery unit occupies a maximum floor area of 2.45 mx 4.20 m if the above dimensions are maintained, of course, other dimensions can be used if required. 5 a hall 4 driven by an electric motor 12 mounted on a support bracket 13. A gasket collar 14 is used to penetrate the roof. and the maintenance levels and the stairs connecting them with railings. The blocks and their structures will be explained in more detail later.

Fig. 3 is an exploded view of the heat recovery tomato 9 and the exhaust air blower 4 showing the positioning of the blocks in the tower and the positioning of partly adjacent devices such as the exhaust air blower 4 with electric motors 12 and support nozzles 13. The bottom module 17 of horizontally on the factory floor 10 feet 18 by. It should be noted that the mass of the heat recovery tomato 9 is usually several tens of tons. A reactive silencer may be used as a spacer unit between the bottom 17 and the fan 4. Reference numerals 19a and 19b show the so-called. CHR cells or air-to-air heat exchangers. The number of these can vary, usually at least one, typically two, even three or more can be selected as needed. The next block is the so-called. washer block 20, followed by usually two so-called "wash" blocks. AHR-20 cells 21a, 21b or air-to-water heat exchanger. The number may also vary. . at least in the range 1-3, although more can be selected as needed. Next, * / tower 9 upwards generally uses a washer block 22, above which is itself · · ·; · * Empty extension blocks 23a, 23b to reach the ceiling of the factory hall 11, above which the roof sealing collar 14 is used. The upper part is next provided with a silencer 24, above which is a contraction cone 15 and a tube 16 from which • «V ·· ty air is freely released into the atmosphere.

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Fig. 4 shows three-dimensional directions of factory-mounted parts of the factory, which are a fan 4, an electric motor 12 on a bracket 13 and a base 17 with a foot 18. The reactive damper 25 is disposed between and 4 between the fan 4 and the base 17; The purpose is to dampen the noise generated by the fan. The reactive damper 25 has a damping chamber separated by a hole in the central flow opening. In general, a relatively short reactive damping device, / 25, is used, e.g. in a flow direction about 0.7 m long. It is important that the joints are • tightly sealed to prevent leaks and the resulting damage.

Figure 5a shows the interconnection structure between the blocks in a three-dimensional direction and cut before the upper block 27 is lowered to its final position. Reference numeral 8 118826 26 denotes a lower section whose wall plate is bent outwards to the horizontal by a distance, e.g. 5 cm, and further upwards by a distance, e.g. 5 cm. The lower part of the upper block 27 is first bent outwards to a level approximately 5 cm and then upwards to 4 cm. The lower part 5 of the upper block has guide wedges 38 which act as guide means for mounting the upper and lower blocks. The guide wedge 38 rests on the guide surfaces of the side reinforcement profile 33. By welding all the vertical joints in the block, vertical flange joints are completely avoided. This also avoids crossing flange joints which have been known to have problematic sealing. At such sites, there has been ai-10 more tendency to use a sealing compound, e.g. a silicone compound, which may be dispensed with in the structures of the invention. The gasket will remain well in place during installation, since during installation the upper block will be lowered onto the lower block and the gasket will not be exposed to any lateral load. Since the fastening screws are not located on or near the sealing surface, the fastening screws do not clamp the seal 15 as was often the case in previous structures, so that little deformation of the structure occurs and thus no risk of leakage. Finally, a pin (not shown) or the like is threaded through the holes 31a and 31b to lock the two blocks together.

In Fig. 5b, the upper block and the lower block are already attached to each other, i.e. in place. The mass above the heat recovery tom 9 is provided by the press 28 of the seal 28. . The seal 28 is compressed by about 20-35% thinner than the original thickness [I ", whereby the seal 28 functions as a sealing member in the correct manner. The additional • · t | · 'crossing is prevented by a structural solution such that the side reinforcement profiles:. the ends meet each other at the point when the compression of the gasket 28 is suitable.

• ·, ·. Fig. 6 shows the angular structure of the upper section 26 of the lower block 26 with its seal 28. The outer corner of the block · · · · has a vertically welded corner reinforcement profile 32. The corners of the seal t · 28 are cut to 45 degrees and vulcanized together to 90 degrees.

“It is recommended that the seal is taped in place, for example, with double-sided adhesive tape, when the seal is in place and protected during transport and •« ... ...

* ··· * 30 during installation, as the flange prevents the seal from being damaged. It should be noted that: * ·. * The flange also forms a fairly rigid structure, so the flange has a clearly stiffening effect. Thus, no silicone mass is required for further sealing.

Fig. 7 shows the so-called. AHR block 21a while cell replacement is in progress. Module 21a has conventional corner reinforcement profiles 32 according to the invention at all four corners on the outer surface and furthermore vertical side reinforcement profiles 33 on all sides, with a mutual spacing of up to about 1 m is recommended.

9 118826 In the AHR block, the heat energy contained in the upstream medium, moist air, is recovered by heating water, which is circulated in the heat exchanger plate of the heat exchanger. The AHR block 21a has at its end a manifold 34 for supplying water to the heat exchanger plates, one of which plate 35 is removed for replacement from the AHR block head service port 36b. The number of disks is usually several dozen in one AHR block. The other service openings 36a and 36c are located in the areas between the head reinforcement profiles. For commissioning, the service doors 37a-37c are secured in place to seal the service ports 36a-36c. It should be noted that maintenance work can be performed through the block end apertures 36a-36c without disassembling the co-10 co heat exchanger. Figure 7 also shows guide wedges 38 at the ends of each corner reinforcement profile 32 and side reinforcement profile 33. In Fig. 7 they are placed at the lower ends, but an alternative upper end installation is also possible. The purpose of the guide wedges 38 is to assist in the installation step, since when the wedge 38 hits a corresponding hole in the reinforcement profile in the lower block 15, the upper block is well guided and the sealing points also fit well. Since the block is many meters long, the support bars 39 are used to keep the long side walls at a proper distance from each other. Transverse support members, such as draw bars (not shown), can also be used, if necessary, to maintain the horizontal section of the block in rectangular form.

Figure 8 shows the attachment of a treatment level bracket to the side reinforcement profile 33. It is,. it is necessary to equip the heat recovery tom 9 at some sides and at some height ♦ · · "with maintenance levels that greatly facilitate inspection, kayaking and maintenance work.

• · * * · * Side reinforcement profiles 33 are strong enough to withstand the stresses of care and maintenance: V men. The service platform bracket 40 is made of sheet steel ***** 25 by cutting and bending and thus only in one piece. The upper pole 41 is of the desired length, e.g. 0.7 m, to support a sufficiently wide treatment level. The upper beam 41 is: ***: of the vertical members bolted by nuts 42 from the hole 42 to the side reinforcement profile 33, and the lower arm 43 resting somewhat on the same side reinforcement profile 33, e.g. 0.3 m below. The lower beam 43 is inclined upwardly away from the block, such that at the outer end of the bracket 40 the lower beam 43 and the upper beam 41 are approximately 0.15 · · **. ' m apart in height. Near said outer end, the upper beam *. ** has a hole 44 for securing the railing post. The handrail structure shown is ***** extremely simple to fabricate and install, as well as robust and durable. It can also be dismantled very quickly if necessary. The level of care itself may be a grate known per se * »35 · or equivalent.

• ·· • «118826 ίο

The heat recovery tomato 9 according to the invention operates by blowing the damp air 4 through the pipelines in the recovery process. The noise of the fan 4 is reduced by the attenuator 25. The heat recovery unit 9 is superimposed on the desired units, which include at least heat exchangers, washers, water collector 5 nozzles, droplets, if necessary extensions, and a silencer and contraction cone at the top. Generally, the heat recovery tomato includes at least one separating apparatus for separating water from the moist air or steam which is passed through the heat recovery tomato. With the above-mentioned volume measurements, the flow rate is usually 35 to 50 m3 / s and the discharge mass flow rate 10 is usually 20 to 40 kg / s dry air. Tom typically has a mass of 15-50 tonnes. The solution according to the invention typically saves 20 -50% of the total cost of the factory project, manufacturing, transporting and installing the tower compared to prior art. The heat recovery unit 9 is assembled from standardized standard components for which tests have already been carried out at the manufacturer's 15 factories. As a result, delivery-specific tower design is completely eliminated. It is also important to keep the tower tight, as leaks cause at least aesthetic damage even in a relatively short period of time.

The invention is not limited to the appended embodiment, but many variations thereof are conceivable within the scope of the appended claims.

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Claims (7)

1. Heat recovery apparatus for at least partial recovery of heat energy from hot air or other gas formed in an industrial plant, to which includes at least one or more heat exchangers, to which the equipment for heat recovery (9) belongs to the following units, which are located from below in storage on each other, and which carry themselves and the load directed at them - a bottom pool (17), - one or more air / air heat exchangers (19a, 19b), - a wash block (20), 10. one or more air / water heat exchanger (21a, 21b), - a wash block (22), - alternatively one or more extension blocks (23a, 23b), and a sealing cuff (14), a silencer (24), a diminishing cone (15) and a sealing tube (16). 15 2. A heat recovery body according to claim 1, characterized in that there are 1 to 3 pieces of said air / air heat exchangers (19a, 19b). Heat recovery body according to claim 1 or 2, characterized in that there are 1-3 pieces of said air / water heat exchangers (21a, 21b). . . 4. A heat recovery body according to any of the preceding claims, characterized in that at least most of the units placed on each other by means of control means, between themselves, are at least approximately equal in size: V applies to their horizontal outer dimensions and outer shapes. * · A heat recovery body according to any of the preceding claims, characterized in that the horizontal cross-section of the heat recovery body (9) in its outer shape is at least close to the shape of a rectangle.