GB2251061A - Apparatus for heat exchange between different liquid media - Google Patents

Abstract

Apparatus for transfer of heat between different liquid media, such as for example sludge, sewage water, industrial process water or the like allows the transfer of heat between two polluted media. from a polluted medium to a clean medium or vice versa. A number of generally planar, parallel panels (A) are disposed one above the other. Suitably disposed partitions form intermediate, sinuous ducts. The ducts can be arranged in parallel or in series. They can be of a variable dimension, depending on instant placement and number of partitions determining the cross-sectional area of the duct. Hot and cold medium ducts (C, D, respectively) are arranged such that the flow of the two media takes place in a cross- and a counter-flow fashion along the ducts. The transfer of the respective medium (C; D) from one plane of the respective duct to another is carried out by means of end boxes (E). The partitions of the ducts, straight or curved, are detachably clamped by a suitable framework (G). <IMAGE>

Description

APPARATUS FOR HEAT EXCHANGE BETWEEN DIFFERENT LIQUID MEDIA The present invention relates to an apparatus for heat exchange between different liquid media, such as sludge, sewage water or industrial process water.

The transfer of heat may be arranged to take place between two or more polluted media, from a polluted medium to a clean medium, or vice versa.

There already exists air-to-air apparatus for heat exchange as described, for example, in U.S. patent 4,141,412.

A preferred embodiment of the present invention may be an apparatus which is compact, and able to provide effective heat exchange, and which has a relatively low risk that its passageways become clogged.

According to the invention, there is provided a panel heat exchanger for liquid media comprising an array of panels; guide partitions disposable between adjacent panels to form flow channels; connecting channels disposed in use at edges of the panels; and a framework by which the partitions are firmly but detachably clampable between the panels. Thus it can be arranged that the position and size of the partitions relative to the panels of a given frame work is variable. A preferred form is apparatus for heat exchange between different liquid media, such as sludge, sewage water, industrial process water or the like, wherein the heat exchange takes place either between two or more polluted media or between a polluted medium and a clean medium.

The apparatus presents a combination of a plurality of flat parallel sheets disposed one above the other to form a plurality of generally planar duct sections. A system of partitions disposed between each pair of adjacent sheets forms a duct. The intermediate duct panels can be arranged either in parallel or in series relative to each other. The apparatus further comprises means for conducting a hot and a cold medium, respectively, over the sheets such that the flow of hot and cold media takes place in cross- and counter-flow fashion along ducts.

The partitions combining with the sheets to form the ducts, are detachable, and may be straight or curved.

They are clamped on by means of a frame in a liquid- and air-tight fashion.

The invention will now be described in more detail and with reference to the accompanying drawing, in which FIGURE 1 is a simplified, diagrammatic perspective view, showing an embodiment of the apparatus with certain parts broken away or removed for clarity; and FIGURES 2 and 3 are diagrammatic plan views showing two alternatives of the partitions as mentioned above.

FIGURE 1 shows an apparatus in which a hot and a cold medium, respectively, are conducted over a number of flat parallel sheets A. In the shown embodiment, the sheets A are horizontal and are located one above the other. The flow of a hot medium through duct C and a cold medium through duct D, respectively takes place in cross- and counter-flow fashion. The transfer of the hot medium and the cold medium from one sheet plane or duct section to another takes place by means of four end boxes E.

The ducts C, D can be produced in different ways.

They can be connected in parallel or in series. In the shown embodiment, the ducts C on the hot side and ducts D on the cold side, respectively, are located at right angles to one another. Thus, all ducts C on the hot side and on the cold side respectively are cleanable and accessible from two separate directions upon removal of cleaning door B. There may be such doors on all sides.

The length, width and height of the ducts can be varied at both the hot and the cold side. The length, width and height of the ducts does not have to be the same at the hot side as that of the cold side. Alternate spaces (between adjacent sheets A) will generally accommodate ducts of alternating series (C, D,), so that thermal transfer can occur through the sheets.

The speed of the medium flow in duct bends G may be varied in relation to the speed of the medium in the straight section H of the same duct. This is accomplished by the partitions forming the ducts being detachable from the panels A.

The partitions I are firmly clamped to the adjacent panels A by means of a frame J (shown only diagrammatically by a broken line) to provide a sealed arrangement. The partitions I can be arranged, for example, in the form of either one of the alternatives shown in FIGURES 2 and 3. These provide an inter-panel space with a duct composed of parallel straight duct portions connected in a serpentine array.

The design of the apparatus or the heat exchanger permits heat exchange from one medium to one medium or from a plurality of media to one medium in one and the same apparatus. For example, cold sewage sludge entering the apparatus can be placed into heat exchange relationship with outgoing hot sewage sludge to a certain technical/economic limit. Subsequently, the remaining amount of energy in the outgoing hot sewage sludge can be utilized by transfer of heat to, for example, a glycol circuit which, in turn, preheats cold incoming ventilation air by means of a glycol/air battery. The cold medium can be finally heated to the required extent, for instance by hot water from a boiler or heat pump.

The transfer of heat between sludge and glycol, and between hot water and sludge, respectively, takes place in the same manner as in the case of a sludge/sludge application, and all transfer of heat thus takes place in the same apparatus or heat exchanger. It is, of course, an easy matter to arrange the apparatus so that there are intermediate inlets and outlets so that, for example, a first cold medium can be passed through ducts defined in the first, third, and fifth interpanel spaces while a second cold medium can be simultaneously passed through ducts defined in the seventh, ninth, and so on spaces.

An alternative with a heat pump would also be feasible. In such a case, the heat pump may utilize the outgoing hot sludge as heat source. The heat from the heat pump can either heat the cold medium on the apparatus or heat exchanger or transfer the heat to some other application, such as heating of water, heating of air or the like.

The invention is obviously not limited to the described embodiment, but can naturally be varied within the scope of the present invention.

Claims (17)

Claims

1. A panel heat exchanger for liquid media comprising guide partitions disposed between adjacent panels of the heat exchanger to thus form flow channels, connecting channels disposed at edges of the panels and a frame work by which the partitions are firmly clamped between the panels, characterized in that the position and size of the partitions relative to the panels of a given frame work is variable.

2. A heat exchanger as claimed in claim 1, wherein the channels are accessible through cleaning doors.

3. Apparatus for heat exchange between liquid media comprising, in combination a plurality of flat parallel sheets or panels disposed one above the other; duct means for conducting a hot medium and a cold medium, respectively, over the sheets such that the flow of hot and cold media takes place in cross- and counter-flow fashion, the transfer of the respective medium from one sheet or panel to another sheet or panel being provided for by at least two end boxes; each duct means being defined by a pair of said sheets or panels disposed one next to the other, and by straight or curved partitions detachably clamped in a liquid and air-tight fashion to said pair of sheets or panels by means of a clamping device.

4. An apparatus according to claim 3, wherein the sheets or panels are rectangular and form a rectangular prism-shaped stack; the partitions are straight; the duct means on a hot side and on a cold side of the apparatus, respectively, are coextensive with generally vertical planes disposed at right angles relative to each other, and four cleaning doors are removably engaged in air and liquid tight fashion to the sheets or panels and to ends of the respective partitions, one at each side of the stack, whereby the respective duct means is cleanable and accessible simultaneously from two opposed directions upon opening or removal of the opposed doors.

5. An apparatus according to claim 3, characterized in that the speed of the medium in bends of the duct means is variable in relation to the speed of the medium in straight portions of the duct means.

6. Heat exchange apparatus for effecting heat exchange between first and second liquids, comprising: a multiplicity of panels disposed in a spaced superposed array so that respective liquid flow spaces are defined between adjacent panels; partitions disposed between adjacent panels and arranged to define with them liquid ducts providing flow pathways repeatedly traversing the flow spaces; and duct connector means for communicating liquid ducts of different flow spaces; the assembly providing at least two flow paths for different liquids and permitting thermal transfer between them.

7. Apparatus according to claim 6 wherein said two flow paths comprise arrays of said ducts connected by respective connector means, said ducts and connector means being arranged so as to allow for cross- and counter-flow of different liquids.

8. Apparatus according to claim 6 or claim 7 wherein the flow paths for different liquids comprise liquid ducts of different respective flow spaces.

9. Apparatus according to claim 8 wherein at least some panels permit thermal transfer and are located between flow spaces through which, in use, different liquids flow.

10. Apparatus according to any of claims 6-9 wherein the connector means comprise end boxes extending across the ends of the array of panels.

11. Apparatus according to any of claims 6-10 wherein the connector means are arranged so that ducts of even-numbered flow spaces are mutually connected, as are ducts of odd-numbered flow spaces.

12. Apparatus according to any of claims 6-11 having at least two sets of ducts, the ducts in each set being connected by the connector means either in series or in parallel.

13. Apparatus according to any of claims 6-12 wherein the partitions are detachable, and the assembly of panels and partitions is held together sealedly and demountably by clamping means.

14. Apparatus according to any of claims 6-13 wherein the panels are substantially rectangular and the partitions and ducts extend parallel to edges of the panels, the ducts in a given flow space being parallel to a given edge; the array of panels having end doors which are removable to facilitate cleaning of the ducts.

15. Heat exchange apparatus such as herein described with reference to and as illustrated in the accompanying drawings.

16. A method of effecting heat exchange between liquid media comprising flowing said media through apparatus according to any preceding claim.

17. A method according to claim 16 wherein the media comprise one or more of sludge, sewage, and industrial process water.