GB2189589A

GB2189589A - Plate heat exchangers

Info

Publication number: GB2189589A
Application number: GB08609148A
Authority: GB
Inventors: Alan James Clegg
Original assignee: Bcl Ltd
Current assignee: Bcl Ltd
Priority date: 1986-04-15
Filing date: 1986-04-15
Publication date: 1987-10-28
Also published as: GB2189589B; AU7133187A; EP0242063A2; EP0242063A3; GB8609148D0

Abstract

A plate heat-exchanger which is readily dismantled for cleaning with the minimum of down-time comprises a set of parallel spaced apart heat-conducting plates 10 mounted in a frame member 2 surrounding and engaging the entire peripheries of the plates. The plates are so mounted to the frame member, for example in grooves or in rubber or plastics tracks, that they are readily detached and removed for cleaning and/or replacement when a portion of the frame member is removed e.g. opens upon a hinge. Two separate fluids are introduced into and exhausted from alternating sets of channels formed between the plates through inlet and outlet passages 14, 15 and 16, 17 in the frame member whereby heat- exchange takes place through the plates. The fluids may travel at right angles to each other, co-currently or in counter-current. <IMAGE>

Description

1 GB2189589A 1 SPECIFICATION respondingly rectangular plates are kept

paral lel and separated from each other by their Heat exchangers peripheries being held within grooves formed in the inner surface of the frame member. One This invention is concerned with heat-ex- 70 side of the rectangular frame member is remo changers. Heat-exchangers of conventional vable or preferably hinged so that the plates type comprise two sets of fluid channels se- are exposed and can be readily withdrawn parated by heat conducting walls, such as from the grooves by hand for cleaning or re metal walls, whereby a hot fluid passing placement.

through one set of channels transfers some of 75 The plates are preferably of metal such as its heat through the walls to a cooler fluid aluminium.

passing through the other set of channels. In one form of the invention the first inlet The fluid may be a liquid, a vapour or a gas. passages and the first outlet passages lie on By such means, in industrial and other pro- opposite sides of the frame member and the cesses which use large amounts of energy, 80 second inlet passages and second outlet pas economy in the use of energy can be sages lie on further opposite sides of the achieved by passing hot exhaust liquids, va- frame member such that the fluid flowing in pours and/or gases through a heat-exchanger the alternate flow channels travels at right when heat is extracted and returned to the angles to the second fluid flowing in the inter process, for example, by way of ingoing fresh 85 mediate flow channel.

fluids. In another form of the invention one set of However, one problem which occurs is that the inlet passages are confined to a portion of exhaust fluids often carry additional waste ma- the frame member near one end of the heat terial which deposit upon the heat-conducting exchanger and the corresponding set of outlet walls of the heat-exchanger and reduce the 90 passages are confined to a portion of the op width of the fluid channels as well as interfer- posite side of the frame member near the ing with the heatconducting efficiency of the other end of the heat- exchanger such that separating walls between the channels. Even- fluid passing through the flow channel corre tually, such a contaminated heat-exchanger sponding with the sets of inlet and outlet pas has to be scoured through with cleansing 95 sages travels partly at right angles to and fluids or be discarded. Both prccedures are partly parallel with the fluid passing through expensive and time consuming. the other flow channels.

The present invention is concerned with a The invention will now be more specifically heat-exchanger in which the heat-conducting described by reference to the accompanying walls are readily available for replacement an- 100 drawings, in which:

d/or cleansing of deposits. Figure 1 is a diagrammatic illustration (partly According to the present invention, a heat- exploded) of a heat-exchanger in accordance exchanger comprises a set of parallel,spaceda- with the invention, and part heat-conducting plates defining between Figure 2 is a diagrammatic illustration of a them a set of fluid flow channels, a frame 105 further embodiment of the heat-exchanger.

member surrounding and engaging the entire In Figure 1, the heatexchanger body 1 is peripheries of each of the plates, first inlet box-like in shape, consisting of a rectangular passages through the frame member opening frame member 2, which in turn consists of a into alternate flow channels through which a vertical frame 3, a top frame 4, a bottom fluid may be introduced into the alternate flow 110 frame 5, and a door member 6 hinged to channels, first outlet passages through the frames 3 and 4, and two end members 7,8.

frame member opening into the alternate flow Frames 3,4 and 5 have grooves 9, formed on channels through which the fluid may be dis- the inside to receive the peripheral edges of charged from the alternate flow channels, sec- plain metal plates 10, (for example, of alumi ond inlet passages through the frame member 115 nium) of a series 11 of such plates 10, and opening into intermediate flow channels be- hold within the body 1 the series 11 of plates tween and immediately adjacent to the alter- 10, in parallel spaced relationship, so forming nate flow channels through which a second channels 12, between the plates 10, through fluid may be introduced into the intermediate which fluids can flow as explained below.

flow channels and second outlet passages 120 The door member 6, has rubber strips 13, through the frame member opening into the mounted in such a position as to make con intermediate flow channels through which the tact, on closing, with the exposed edges of second fluid may be discharged characterised the plates 10, so as to ensure that each plate in that each plate is readily detachable from 10 is firmly engaged within the body 1 so its engagement with the frame member and a 125 that each channel 12 is sealed from each portion of the frame member is readily remo- other channel 12.

vable from the frame member whereby the In the frame 4, inlet passages 14, pass plates can be readily withdrawn and replaced. through the frame 4 into each alternate chan In a preferred form of the invention, the nel 12 (designated as 12A) and outlet pas- frame member is rectangular in shape and cor-130 sages 15, pass from each channel 12A 2 GB2189589A 2 through the frame 5. Similarly inlet passages quired to connect with the alternating sets of 16, pass through the frame 3 into channels passages.

12 (designated as 1213) which are between In Figure 2 there is illustrated an alternative and immediately adjacent to the channels construction for achieving a substantially coun 12A, and outlet passages 17, are formed in 70 ter-current flow of the fluid and second fluid.

the door member 6, which open into channels The heat-exchanger 18 of Figure 2, is of simi 12B when the door is closed. lar construction to the heat-exchanger 1 of In operation, when the door member 6' is Figure 1, except that in the frame 3 the inlet closed, hot fluid, for example hot exhaust air passages 16 are confined to a bottom portion from an industrial plant, enters channels 12A 75 of frame 3 while the outlet passages 17 are through the inlet passages 14, from a com- confined to a top portion of door member 6.

mon manifold (not shown) and passes out By these means, access to the channels 12A from the channels 12A through outlet pas and 12B is made through the inlet passages sages 15, to a common exhaust manifold (not 14, 16 and outlet through outlet passages 15, shown). A second fluid passes into the chan- 80 17, by way of simple manifolds 19, 20, 21, nels 12B through the inlet passages 16, and and 22. The direction of the fluid through the out of the outlet passages 17, in a direction channels 12A is vertically downwards while at right angles to the direction of the fluid in the second fluid which passes through the the channels 12A. The second fluid (for channels 12B is partly horizontal but substan- example, fresh air being drawn.into an indus- 85 tially vertically upwards (as shown by the line trial plant) is at a lower temperature than the 23) thus providing the optimum conditions for fluid flowing in the channels 12A and it is an efficient heat-exchange through the plates heated by heat transferred from the fluid in 10.

the channels 12A through the plates 10, into The fluid and second fluid may be a liquid, a the channels 1213. The deposit of any un- 90 vapour or a gas. The heat- exchanger in accor wanted material on the plates 10 from the hot dance with the invention is particularly useful fluid is discouraged by the smooth surface of in taking heat from exhaust gases leaving a the plates and the -washing down- action of stenter used for the orientation of plastic films the fluid passing vertically downwards through and transfering the heat to fresh gases enter- the channels 12A. 95 ing the stenter which are to be used for heat However, despite the self-cleaning effect of treatment of the films. Waste materials carried the fluid passing downwardly in the channels by the exhaust gases which condense on the 12A, in the course of time, deposits do tend plates 10 can readily be removed, from time to collect upon the surfaces of the plates 10 to time, by sliding out the plates 10 and facing into the channels 12A and so constrict 100 either cleaning immediately or replacing by the width of the channels 12A and reduce the clean plates 10.

heat conductivity of the plates 10. When this When it is essential that the plant process happens, the heat-exchanger 1 is rapidly is not brought to a halt, two heat exchangers brought back to high efficient working by in parallel may be installed so that one can be opening the door member 6, sliding out the 105 operating while the other is being cleaned.

plates 10, from the grooves 9, and replacing Although the plates 10 are preferably them with either new or with cleaned plates mounted within grooves formed in the frame 10. On closing the door member 6, the heatmember 2, other mountings, such as rubber exchanger 1 is ready to be brought back into or plastic tracks may be used providing that operation. Due to the novel construction of 110 the plates 10 are readily removable and repla the heat-exchanger 1, the time taken to re- ceable.

plenish the plates 10 by hand is at a mini

Claims

mum. CLAIMS

In the heat exchanger illustrated in Figure 1, 1. A heat-exchanger comprising a set of the fluid passing through channels 12A travels 115 parallel spaced,apart heat-conducting plates at right angles to the second fluid passing defining between them a set of fluid flow through channels 12B ("cross-flow"). A more channels, a frame member surrounding and efficient heatexchange through the plates 10 engaging the entire peripheries of each of the occurs if the fluid in the channels 12A travels plates, first inlet passages through the frame in the same direction as the second fluid in 120 member opening into alternate flow channels channels 12B (-co-current flow") and still through which a fluid may be introduced into more efficiency is achieved if the fluid in chan- the alternate flow channels, first outlet pas nels 12A travels in the opposite direction to sages through the frame member opening into the second fluid in channels 12B (-counter- the alternate flow channels through which the current flow"). In these circumstances how- 125 fluid may be discharged from the alternate ever, passages for introducing or exhausting flow channels, second inlet passages through the fluid and second fluid from the respective the frame member opening into intermediate channels, 12A and 1213, occur in common flow channels between and immediately adja frames (for example frames 4,5) so that corn- cent to the alternate flow channels through plicated sets of manifolds (not shown) are re- 130 which a second fluid may be introduced into 3 GB2189589A 3 the intermediate flow channels and second outlet passages through the frame member opening into the intermediate flow channels through which the second fluid may be discharged characterised in that each plate is readily detachable from its engagement with the frame member and a portion of the frame member is readily removable from the frame member whereby the plates can be readily withdrawn and replaced.
2. A heat-exchanger as claimed in claim 1 in which the frame member and plates are rectangular.
3. A heat-exchanger as claimed in claim 1 or claim 2 in which the plates are held within grooves formed in the inner surface of the frame member.
4. A heat-exchanger as claimed in claim 1, claim 2 or claim 3 in which one side of the frame member it hinged to permit removal of the plates.
5. A heat-exchanger as claimed in any one of the preceding claims 1 to 4 in which the plates have plain smooth surfaces.
6. A heat-exchanger as claimed in any one of the preceding claims 1 to 5 in which the first inlet passages and the first outlet passages lie on opposite sides of the frame member and the second inlet passages and second outlet passages lie on further opposite sides of the frame member such that the fluid flowing in the alternate flow channels travels at right angle to the second fluid flowing in the intermediate flow channel.
7. A heat-exchanger as claimed in claim 6 in which one set of the inlet passages are confined to a portion of the frame member near one end of the heat-exchanger and the corresponding set of outlet passages are confined to a portion of the opposite side of the frame member near the other end of the heat-exchanger such that fluid passing through the flow channels corresponding with the sets of inlet and outlet passages travels partly at right angles to and partly parallel with the fluid passing through the other flow channels
8. A heat-exchanger as claimed in claim 1 substantially as described with reference to Figure 1 or Figure 2 of the drawings.
9. The use of apparatus as claimed in any one of the preceding claims for extracting heat from exhaust gases leaving a stenter used for the orientation of plastic films and transferring the heat to fresh gases entering the stenter which are to be used for heat treatment of the films.

Printed for Her Majesty's Stationery Office by Burgess & Son (Abingdon) Ltd, Dd 8991685, 1987. Published at The Patent Office, 25 Southampton Buildings, London, WC2A l AY, from which copies may be obtained.