JPH0127358B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat exchange guarantee device between a gas stream and a heat exchanger.

As energy prices soar, effective use of energy has become important. In various industrial processes, energy transfer between gas streams and heat exchangers is necessary, and it is desirable that this transfer occur as efficiently as possible. Furthermore, once efficient energy transfer is achieved, the energy emitted from various industrial processes can be recovered economically. For example, the temperature of the air exhausted from an industrial process or air-conditioned building may be either higher or lower than the ambient temperature, and this temperature difference indicates the presence of energy that is desired to be recovered.

In particular, painting booths that use water-based paints or water-soluble paints are supplied with air that is regulated at a predetermined temperature and humidity, and this air is further discharged into the atmosphere. Air conditioning a large amount of air inevitably consumes energy. It is therefore desirable to recover this energy from the exhaust gas.

Techniques have also been proposed in which exhaust gas from a paint booth is passed through a heat exchange coil, and a heat transfer medium is caused to flow within the heat exchange coil such that the heat transfer medium is heated or cooled by the exhaust gas. For example, for some purposes, heat exchange coils are passed through condensate from a cooling facility, and the exhaust from the paint booth cools the condensate.

It goes without saying that the heat transfer to and from the heat transfer medium in the heat exchange coil must be carried out as economically as possible.

When exhaust gas is sent to a heat exchange coil, it is known that moistening the coil with liquid increases the heat transfer rate. Therefore, when cooling the heat transfer medium, the liquid on the coil is evaporated and sent into the air passing through the coil. As the liquid evaporates, it absorbs heat from the heat exchange coil.

However, significant heat transfer increases can only be achieved if the coil is completely wet.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a heat exchange guarantee device between a gas flow and a heat exchanger that can efficiently transfer heat.

According to the present invention, a heat exchange guarantee device between a gas flow and a heat exchanger includes: a gas flow generating device that allows dust to flow through the duct; a heat exchanger that is installed in the duct so that the gas flows through the duct; It consists of a device for atomizing the liquid and a throttle arranged in the direction of the gas flow upstream of the heat exchanger and compressing the gas flow so as to generate a gas jet.

The high velocity of the gas jet produced by the compression allows the liquid to be delivered to the heat exchanger, so that the heat exchanger is thoroughly wetted. Because of the power required to create such a high velocity gas flow, it is quite uneconomical to create a very high velocity total gas flow within the duct to achieve a similar effect.

In some embodiments of the invention, compression is achieved by a diaphragm mounted across the duct and having a plurality of passageways extending into the duct. The channels, or some of them, converge in the direction of the gas flow to increase the jet velocity and minimize subsequent contractions. Additionally and/or alternatively, the channel dimensions can be made variable so that the device can accommodate changes in the desired performance of the system in which it is incorporated and/or changes in the variables of the device. .

In one embodiment, the duct extends vertically and air is restricted to flow upwardly through the duct.
A perforated diaphragm extends horizontally across the duct and below the heat exchanger. The periphery of the diaphragm is sealed against the duct. Liquid flowing out from the duct wall and the heat exchanger therefore collects across the diaphragm.
Gas jets formed through the holes direct the liquid collected on the plates into the heat exchanger. Therefore, the surface of the heat exchanger can be reliably moistened with the liquid sent from the diaphragm by the gas flow.

The liquid is preferably atomized from one or more nozzles within the dust and directed into the duct.
Various nozzle shapes can be used. For example, one or more nozzles can be placed below the diaphragm and oriented upwardly towards the heat exchanger, in which case the diaphragm must have appropriate openings aligned with the nozzles. There is. Additionally or alternatively, one or more nozzles may be disposed above the heat exchanger and oriented downwardly towards the heat exchanger. The number, shape, and mounting location of the nozzles are selected depending on the desired heat transfer rate, acceptable gas pressure drop, and heat exchanger dimensions.

In another embodiment particularly useful for energy recovery from airflow, the heat exchanger is a coiled tubular heat exchanger that is divided into two parts: a first main part and a second reserve part. The two parts are mounted in the duct with the main part spaced above the spare part. A perforated diaphragm is mounted between the two parts and a water spray nozzle is arranged to direct water into the main part. The perforated diaphragm thus acts to completely wet the main area. If desired, additional water nozzles may be provided to water the reserve area.
It is not clear that there is a need for an additional perforated diaphragm below the reserve, although such an additional diaphragm could of course be provided.

The two coil sections are coupled together to form part of a common heat transfer medium circuit. The heat transfer medium flows in the opposite direction of the air flow according to well-known principles.

Next, details of the present invention will be explained with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a reliable heat exchange device between a gas stream and a heat exchanger. The device has a duct 2, preferably made of galvanized sheet metal, formed by walls 4 extending approximately vertically. The duct 2 has a rectangular cross section, although a duct having any desired cross section may be provided. The main heat exchanger 6 is installed across the duct 2. The heat exchanger 6 is constituted by a coiled tube 8, and the tube 8 is provided with fins 10 in a known manner. The coiled tube 8 extends through the duct wall 4 and is supported on a support 12 fixed to the outer surface of the wall 4. Therefore, the heat exchanger 6 can effectively use the inner area of the duct. One end 14 of the tube 8 is the inlet for the heat transfer medium, and the other end 16 is the outlet for the heat transfer medium.

The preheat exchanger 18 is installed across the duct 2 and is spaced apart from the main heat exchanger 6.
The preheat exchanger 18 is likewise constituted by a coiled tube 8' with fins 10', the coils of the tube 8' extending through the duct wall 4 and supported on a support 12'. One end of the coiled tube 8' forms the inlet for the heat transfer medium and is connected to the outlet 16 of the main heat exchanger 6. The other end of the coiled tube 8' is an outlet for the heat transfer medium.

A rectangular perforated plate or diaphragm 24 is mounted so as to extend across the duct 2 between and spaced from the two heat exchangers 6 and 18. The diaphragm 24 is supported by a right-angled iron frame 26 fixed to the inner surface of the duct wall 4, for example by welding. The entire periphery of the diaphragm 24 is welded or sealed to the frame 26.

The diaphragm 24 is made of a suitable material and has a suitable thickness so as to have enough rigidity to maintain a horizontal state. For example, it can be made of galvanized metal sheet. If desired, a support (not shown) can be provided below the septum 24. A series of holes 27 (see FIG. 2) are regularly spaced over the entire surface of the diaphragm 24. Preferably, the holes 27 are sized and spaced such that they occupy about 25% of the membrane surface area.

A pipe 28 with an inlet 30 extends across the duct 2 and above the main heat exchanger 6. The plurality of spray nozzles 32 each face the heat exchanger 6 and are attached to the pipe 28. Furthermore, a pipe 34 with an inlet 36 extends below the perforated diaphragm 24 across the duct 2 . The pipe 34 has a plurality of upwardly directed spray nozzles 3
8 and a plurality of downwardly directed spray nozzles 40 aligned with each of these upwardly directed nozzles. Each nozzle 38 extends through a respective opening 27 in diaphragm 24 .

In use, the duct 2 is arranged in such a way that a gaseous body, for example air, from which energy is to be recovered flows upwardly through the duct as indicated by arrow A. For example, the duct 2 can be coupled to receive exhaust air from a paint booth.

A heat transfer medium, such as glycol, flows through two heat exchangers 6 and 18. The heat transfer medium enters the inlet 14 and passes through the coil 18 to the outlet 16. As a result, the medium enters the coil 8' through the inlet 20 and exits through the outlet 22 after passing through the coil 8'.
In this way, the heat transfer medium flows in a direction opposite to the airflow through the duct 2 according to well-known principles.

It will be appreciated that since the heat transfer medium is heated or cooled by the air flow, the energy thus imparted to the air flow can be used as required. For example, if the exhaust gas is cold, it can be used to cool the condensate from the chiller. This condensate becomes a heat transfer medium flowing through the heat exchangers 6 and 18.

It is known that the heat transfer coefficient can be increased by moistening the coils 8 and 8'. Thus, during operation, a liquid, for example water, is supplied to the pipes 28 and 34 so that the nozzles 32, 38 and 40 spray the coiled tubes 8 and 8'.

Water sprayed by nozzles 32 and 38 onto main heat exchanger 6 flows through heat exchanger 6 and duct wall 4 and collects on perforated diaphragm 24 . A high velocity jet of air is created as the air passes through the holes 27 in the diaphragm. These air jets transport water from the plates to the heat exchanger 6 to effectively moisten the surfaces of the coiled tubes 8 and fins 10.

In the first embodiment shown in FIG. 1, several rows of spray nozzles 32, 38 and 40 are provided. However, various nozzle shapes can be used. For example, one or each row of nozzles may be replaced with a row of nozzles extending laterally across the duct. Alternatively, the or each row of nozzles can be replaced with a single nozzle. In each situation, if the nozzle faces the heat exchanger 6 and is separated from the heat exchanger by a perforated diaphragm 24, a suitable opening must be provided in the diaphragm 24 to align with the nozzle. In FIG. 1, each nozzle 38 passes through a respective hole 27 in the perforated septum, but if desired, the septum 24 may include additional openings for passage of the nozzles.

Figure 2 shows a square iron frame 2 welded to a duct wall 4.
6 is a plan view showing an embodiment of a perforated diaphragm 24 fixed to a duct by means of 6; FIG. The plate 24 shown in FIG. 2 is used only if a single spray nozzle 38' pointing upwardly towards the main heat exchanger 6 is provided instead of the series of nozzles 38 shown in FIG. . Diaphragm 24 is provided with a central hole 42 that aligns with nozzle 38'.

FIG. 3 illustrates a second embodiment of the device according to the invention, showing a circulation path for water and a heat transfer medium. Third
In the embodiment shown, a single heat exchanger 44 is mounted across the duct. The heat exchanger 44 is constructed of coiled tubing and has an inlet 46 and an outlet 48 for a heat transfer medium, such as glycol. The glycol sent from heat exchanger 44 is sent to a device 50, such as a cooling condenser, for example, where its energy is used. The glycol is then returned to the reservoir 52 from where it is pumped to the inlet 46 by the pump 54.

In the embodiment of FIG. 3, a single nozzle 56 is located below the perforated diaphragm 24. In the embodiment of FIG. A nozzle 56 facing the heat exchanger 44 is coupled to receive water delivered from the mains by a pipe 58 having a pump 60.

FIG. 4 shows a third embodiment of the device according to the invention, in which a single coiled tubular heat exchanger 44 is shown.
is installed across the vertically extending duct 2. The perforated diaphragm 24 is mounted across the duct 2 above the heat exchanger 44, and water is pumped through the heat exchanger 44 from a single downwardly directed spray nozzle located above the heat exchanger 44. 44 sprayed. In this embodiment, the flow flows downward through the heat exchanger 44, collects at the diaphragm 24, and then flows through the plate 24.
It will be appreciated that the embodiment operates in much the same way as the previous embodiment when the air jet formed by 4 is directed into the heat exchanger to effectively wet its surfaces.

Figures 5 and 6 show the fourth and fifth parts of the device of the present invention.
An example is shown. In the figure, the duct 2 is arranged so as to extend substantially horizontally. In the embodiment of FIG. 5, a vertically extending additional duct 64 is connected to the main duct and one or more spray nozzles 66, which are supplied by a pipe 68, are mounted within the additional duct. . Therefore, water is sprayed downward onto the heat exchanger 44. The perforated diaphragm 24 is spaced apart from the heat exchanger 44 and is mounted across the duct 2 in the air flow direction above it. In this embodiment, water does not collect on the diaphragm 24, but the diaphragm 24 generates a jet of air that flows over the surface of the heat exchanger. These air jets carry the water flowing through the heat exchanger, so
The surface of heat exchanger 44 is effectively moistened.

In the embodiment shown in FIG. 6, one or more nozzles are positioned upstream of the septum 24 and aligned with the openings in the septum.

FIG. 7 is a plan view of a perforated diaphragm 24 secured to the duct wall 4, for example by welding or with a sealant. The seam is sealed by applying a strip 70 of waterproof sealant.

In all of the embodiments described above, the perforated diaphragm 24 is shown as having a series of equally sized circular holes 27 spaced equidistantly over its entire surface. However, other shapes of holes can be provided, for example polyhedral holes, and the dimensions and spacing between each hole can be selected as desired.

FIG. 8 is a plan view of another diaphragm 124 with a series of elongated holes 127 drilled therein.

The perforated diaphragm defines an air compression channel upstream of the heat exchanger, thereby generating a high velocity air jet. 9 and 9A are top and cross-sectional views of another diaphragm 224 having a series of elongated orifices 227. FIG. Each orifice 227 has a diaphragm 22
a flange 22 extending substantially perpendicular to the plane of 4;
8 is extruded from the membrane material. As shown in FIG. 9A, each flange 228
defines a tapered air flow path 229. The diaphragm is
The flow paths 229 are arranged so as to converge in the direction of the air flow. This reduces the airflow profile. The contour is configured to minimize constriction of the air jet passing through channel 229.

It has been found that the mechanical strength of the diaphragm can be maintained even with a large number of continuous slots as shown in FIGS. 10 and 11. 10 and 10A are top and cross-sectional views of a diaphragm having multiple rigid strips 326 defining slots 327. In the embodiment shown in FIG. 10, the edges of the longitudinally extending strips 326
It is entering on the plane of 4. Figures 11 and 11
Figure A is a top and cross-sectional view of another diaphragm 424 having a slot 427 defined by a strip 426. In this embodiment, the edges of the longitudinally extending strips 426 form a flange 428 that extends generally perpendicular to the plane of the diaphragm 426 and defines a tapered channel 429. 11th A
As shown in the figure, the diaphragm 426 is formed so that the flow path 429 converges in the air flow direction.

In the embodiments shown in FIGS. 10 and 11, the number and width of strips 326 and 426 can be selected depending on the desired air flow area. In these embodiments, one or more airflow zones may also be formed to direct the airflow to one or more selected areas of the heat exchanger surface. It is advantageous to vary the temperature difference between the airflow and various regions of the heat exchange coil in this way.

In the embodiment shown in FIGS. 12 and 12A, diaphragm 524 is provided with a series of circular openings 527. A cylindrical wall 528 is secured to the edge of each opening, for example by welding, to define an elongated channel 529 extending perpendicular to the plane of the diaphragm. To obtain optimal results from a device according to the invention, the diaphragm must be spaced from the heat exchanger by a predetermined distance. For example, if the cross-sectional area of the heat exchange coil is approximately 2.2 m ² , it is preferable to space the diaphragm from the heat exchanger by 100 to 120 mm. However, other members may intrude on the orthogonal plane to attach the diaphragm. In such cases, the diaphragm 524 may be mounted further apart from the heat exchanger and the length of the wall 528 may be selected such that its free end lies in a plane at the desired distance from the heat exchanger. I can do it.

Since the exact performance of a device according to the invention may not be predictable, adjustment of performance may be required in light of changes in other variables of the device. Figures 13 and 13A illustrate embodiments of diaphragms that may be used to regulate and control airflow. The diaphragm 624 has a number of rigid strips 626 extending laterally of the diaphragm 624 generally parallel to each other. A spindle 630 is fixed to each end of each strip 626 and is pivotally supported in a respective bearing 632 fixed to the square frame 26. In this way, the strip 626 forms a pivotable damper vane.
A laterally extending securing strip 634 is also provided at each end of the diaphragm and is attached to the square frame 26. The vanes pivot and project out of the plane of the diaphragm so as to create air passages 629 between adjacent strips. As shown in FIG. 13A, every other air flow path 629 converges in the air flow direction, thereby generating a high-velocity air jet. Adjusting the position of the damper vanes adjusts the dimensions of the air flow path, thereby adjusting the air jet velocity and thus the thermal efficiency.

Figures 14 and 14A illustrate an embodiment of a diaphragm 724 that can be used when varying air jet velocity is required. In this embodiment, the diaphragm 7
24 consists of two plates 721 and 722, one mounted on top of the other. The periphery of each plate 721 and 722 is housed in a slotted frame 726 attached to the duct. Upper plate 721 is fixed to frame 726, while lower plate 722 is supported by frame 726 for adjustment relative to upper plate 721. To this end, a number of bolts 730 are provided around the frame 726 to bring the frame 726 into contact with the lower plate 722. When the bolts 730 are loosened, the position of the lower plate 722 is changed to the upper plate 7.
21 and then the lower plate 722 can be held in the adjusted position by tightening bolts 730. Each plate 72
A row of holes 727 are provided throughout the areas 1 and 722. Preferably, the size and distribution of the holes in one plate correspond approximately to the holes in the other plate. The lower plate 722 is the upper plate 72
1, it is obvious that the dimensions of the air flow path formed by the holes 727 change.

In the embodiment of the diaphragm shown in FIGS. 8-14, the diaphragm is provided with a central hole 42 for alignment with a water spray nozzle. Of course, this central hole 42 could be omitted and each spray nozzle aligned with an aperture or pore provided in the diaphragm. Furthermore, in the embodiments shown in FIGS. 8 to 13, the diaphragm is exemplified as being fixed to the duct wall by a rectangular iron frame, but other fixing means may be used as necessary. Of course.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of a first embodiment of the device according to the present invention; Fig. 2 is a plan view showing the first embodiment of the perforated diaphragm of the device of the present invention; Fig. 3 is a heat transfer medium supply and heat transfer A piping diagram showing a second embodiment of the device of the present invention, showing an outline of the circulation path required for water supply to the medium; FIG. 4 is a vertical cross-sectional view of the third embodiment of the device of the present invention; FIG. 5 is a diagram of the device of the present invention Fig. 6 is a longitudinal sectional view of the fifth embodiment of the device of the present invention; Fig. 7 shows a case where the perforated diaphragm shown in Fig. 2 is attached to the duct by another method. Plan view; FIG. 8 is a plan view of the second embodiment of the diaphragm used in the device of the present invention; FIG. 9 is a plan view of the third embodiment of the diaphragm; FIG. 9A is a plan view taken along line AA in FIG. A sectional view of the ivy diaphragm; FIG. 10 is a plan view of the fourth embodiment of the diaphragm; FIG. 10A is a sectional view of the diaphragm along line BB in FIG. 10; FIG. 11 is a plan view of the fifth embodiment of the diaphragm. Figures: Figure 11A is a cross-sectional view of the diaphragm taken along line CC in Figure 11; Figure 12 is a plan view of the sixth embodiment of the diaphragm; Figure 12A is a cross-section of the diaphragm taken along line DD in Figure 12. Figure; Figure 13 is a plan view of the seventh embodiment of the diaphragm having adjustable damper blades; Figure 13A is a cross-sectional view of the diaphragm along line EE in Figure 13; Figure 14 is a diaphragm with adjustable dimensions. Embodiment 8 of a diaphragm having a flow path capable of forming a flow path; FIG. 14A is a cross-sectional view of the diaphragm taken along line FF in FIG. 14. 2... Duct, 4... Duct wall, 6... Main heat exchanger, 8, 8'... Coiled pipe, 10, 10'...
Fin, 12, 12'...Support, 18...Preheat exchanger, 24...Perforated diaphragm, 26...Iron frame, 2
7... Hole, 28... Pipe, 32... Spray nozzle, 34... Pipe, 38, 40... Spray nozzle, 42... Center hole, 44... Heat exchanger, 5
0...Cooling condenser, 54...Pump, 56...Nozzle, 58...Pipe, 60...Pump, 64...
...Additional duct, 66...Nozzle, 68...Pipe, 70...Strip, 127...Opening, 12
4,224...diaphragm, 227...orifice, 2
28...flange, 229,429,529,6
29... Air flow path, 324, 424, 524, 6
24,724...Diaphragm, 326,426,626
...Strip, 327,427...Slot,
527...Opening, 630...Spindle, 632
... Bearing, 634 ... Strip, 721, 72
2... Plate, 726... Groove-shaped frame, 727...
…hole.

Claims (1)

[Claims] 1. A duct 2 capable of generating a gas flow A; and a duct 2 capable of generating a gas flow A;
heat exchangers 6, 44 arranged in the duct 2 so that the gas flows through them; devices 32, 38, 40, 56, 62, 66 for atomizing liquid in the duct 2; a diaphragm 24, 12 arranged to extend across the duct upstream of the exchanger;
4,224,324,424,524,624,
724, a plurality of gas flow paths 229, 42
9,529,629 extends through the diaphragm, the gas flow path forms an air flow restriction to produce a jet flow of gas, and the diaphragm is adjacent to a heat exchanger. 1. A heat exchange assurance device, wherein the jet flow of gas is arranged to convey a sufficient amount of liquid to the heat exchanger to completely wet the entire surface of the heat exchanger. 2. The heat exchange guarantee device according to claim 1, wherein at least one of the gas flow paths converges in the direction of the gas flow. 3. The heat exchange guarantee device according to claim 1 or 2, wherein the diaphragm has a device for adjusting the dimensions of the flow path. 4. The heat exchange guarantee device according to any one of the preceding claims, wherein the diaphragm includes a rigid plate, and the rigid plate has a plurality of openings passing through the rigid plate. . 5. A heat exchange guarantee device according to claim 4, characterized in that the openings in the rigid plate occupy substantially 25% of the total area of the plate. 6. The heat exchange guarantee device according to any one of the preceding claims, characterized in that the diaphragm is spaced apart from the heat exchangers 6, 18, 44. 7 The device that sprays liquid inside the duct is the nozzle 3.
8; 127,227,327,427,
527, 627, 727 are provided in the diaphragm and the nozzles are aligned with the opposing openings. 8. characterized in that the device for spraying liquid into the duct comprises a nozzle, the nozzle being arranged in the duct such that it extends through the opening provided in the diaphragm, the nozzle being oriented in the direction of the heat exchanger 6, 44; A heat exchange device according to any one of claims 1 to 6. 9 A device for spraying a liquid in a duct is provided with a nozzle, the nozzle is provided in the duct between the diaphragm and the heat exchanger 6, 44, and the nozzle is provided in the duct between the diaphragm and the heat exchanger 6, 44.
The heat exchange guarantee device according to any one of claims 1 to 6, characterized in that the heat exchange guarantee device is oriented in the direction of. 10 The device for spraying a liquid into a duct is provided with a nozzle, which nozzle is arranged in the duct downstream of the heat exchanger in the direction of the air flow and is directed towards the heat exchanger. A heat exchange guarantee device according to any one of the preceding claims. 11. The heat exchange guarantee device according to any one of the preceding claims, in which the duct 2 is defined by a vertically extending wall 4, wherein the diaphragm is substantially rigid and the duct 2 is defined by a wall 4 extending vertically. , the periphery of the diaphragm is sealed against the wall 4, and the device for generating the gas flow is arranged to direct the gas flow upward through the duct so that the diaphragm A heat exchange guarantee device characterized in that it is provided below the heat exchangers 6, 44. 12. In the heat exchange guarantee device according to any one of the preceding claims, wherein the duct 2 is defined by a horizontally extending wall surface, the duct 2 is defined by a horizontally extending wall surface.
4,124,224,324,424,524,
A heat exchange guarantee device characterized in that 624, 724 are substantially rigid and extend at right angles to the wall of the duct. 13 The device that sprays liquid inside the duct is the nozzle 6.
13. Heat exchange guarantee device according to claim 12, characterized in that the nozzle 66 has a nozzle 66 arranged above the heat exchanger and is oriented downwardly in the direction of the heat exchanger. 14 A second heat exchanger 18 is provided in the duct for passing the gas flow, and the second heat exchanger is provided upstream of the gas flow and spaced apart from the first heat exchanger 6, 44. A heat exchange guarantee device according to any one of the preceding claims, characterized in that a diaphragm is provided between the first and second heat exchangers. 15. Heat exchange guarantee device according to claim 14, characterized in that the first and second heat exchangers are connected to a common circuit for the supply of heat transfer medium. 16 Each of the first and second heat exchangers has coiled tubes 8, 8', and fins 10, 1 are arranged on the coiled tubes.
16. The heat exchange guarantee device according to claim 14 or 15, wherein the heat exchange guarantee device is provided with 0'. 17 The device that sprays liquid into the duct is the nozzle 4.
0, the nozzle is provided upstream of the diaphragm,
17. Heat exchange guarantee device according to claim 16, characterized in that it is oriented towards the second heat exchanger.