US2919114A

US2919114A - Indirect heat exchanger

Info

Publication number: US2919114A
Application number: US705837A
Authority: US
Inventors: Ljungstrom Ake Birger
Original assignee: Rosenblads Patenter AB
Current assignee: Rosenblads Patenter AB
Priority date: 1957-01-07
Filing date: 1957-12-30
Publication date: 1959-12-29
Anticipated expiration: 1976-12-29
Also published as: GB826888A

Description

Dec. 29, 1959 AKE B. LJUNGSTROM 2,919,114

INDIRECT HEAT EXCHANGER Filed Dec. 30, 1957 2 Sheets-Sheet 1 /4/1E B/RGER LJUNGSTR OM INVENTOR.

w zQ a A 7 TOR/V5).

1959 I AKE B. LJUNGSTROM 2,919,114

INDIRECT HEAT EXCHANGER 2 Sheets-Sheet 2 Filed Dec. 30, 1957 A KE B/RGE/E L JUNGS re 0 INVENTOR.

ATTORNEY United States atent Ofiice 2,9

l

9,1 14 Patented Dec. 29, 1959 INDIRECT HEAT EXCHANGER Ake Birger Ljungstriim, Stockholm, Sweden, assignor to Aktiebolaget Rosenblads Patenter, Stockholm, Sweden, a corporation of Sweden Application December 30, 1957, Serial No. 705,837

Claims priority, application Sweden January 7, 1957 1 Claim. (Cl. 2571) It is previously known in indirect heat exchangers having two separate passage systems to which two heatexchanging media are supplied from an outer pipe-line system with detachable connections to the heat exchanger, to arrange the heat exchanger in such a manner that, after disconnection, it can be turned from a certain connecting position in relation to this outer pipeline system into a new connecting position in relation to the pipe-line system, whereby the medium which was previously directed through one passage system, in the new connecting position is passed through the other passage system and vice versa, so that a so-called passage changing will take place. If one medium is apt to precipitate sediments, for example incrustations in the heat exchanger which may be dissolved by the other medium, the sediments can be periodically removed by such a passage changing before they have had time to collect in too troublesome quantities.

It is also known that if a heat-exchanging medium precipitates sedimens or deposits, for example fibres, sludge, etc., which is apt to become caked in the passage system of the heat exchanger the best way to remove these deposits by mechanical flushing is by passing the flushing medium through the passage system in a different direction to that in which the deposits have become caked. In many cases it is not necessary to have resort to flushing with any special medium if the depositing medium is passed periodically in dilferent directions through the passage system.

The main object of the present invention is to provide an arrangement for carrying out change of passages by turning the heat exchanger so that any of its passage systems simultaneously with the change of passages will be passed by fiuid in a dilferent direction to that which existed before the change of passages.

The main characteristic feature of the invention is that there are arranged in fixed connection to the heat exchanger an inlet and an outlet for one of the passage systems as well as an inlet and an outlet for the other passage system, each of said inlets and outlets, four in all, being connected by four detachable pipe-connections to one of four pipes associated with an outer, fixed pipe-system, in which two pipes serve to convey one medium and two pipes to convey the other medium respectively to and from the heat exchanger, which is mounted to turn around a revolving axis around which the four detachable pipe-connections are arranged in a circuit in such a way that in this circuit every alternate pipe-connection connects one pipe for one medium to one passage system, while alternate pipe-connection connects a pipe for the second medium to the second passage system through the said inlets and outlets.

Some embodiments of the invention will now be described with reference to the accompanying drawings in which Fig. 1 shows a heat-exchanger in lateral section arranged according to the invention,

Fig. 2 shows a top view of the arrangement in Fig. 1,

Figs. 3, 4 and 5 show the same arrangement with the heat exchanger in difierent turning positions as compared with Fig. 1,

Fig. 6 shows a side view of another type of heat exchanger according to the invention,

Fig. 7 shows the arrangement according to Fig. 6, in section along the line VIIVII in the latter figure,

Fig. 8 shows the arrangement according to Fig. 6 in section along the line VIII-VIII in the latter figure.

Figs. 9 and 10 show the arrangement according to Fig. 6 with the heat exchangers in different turning positions as compared with Fig. 6, and

Fig. 11 shows the heat exchanger according to Fig. 6 arranged in a modified manner according to the invention, and in a different oscillating position from that in Fig. 6.

Identical details are indicated in the different figures with the same reference characters.

The illustrations are diagrammatic and are only intended to serve as examples. Thus, two different types of heat exchangers are shown, for example, although any kind of two-passage type whatsoever can be arranged in conformity with the invention.

1 is a tubular heat exchanger in which

pipes

2a and 2b having connecting flanges 4a and 4b respectively communicate with the tubes 6, and the

pipes

3a and 3b having connecting

flanges

5a and 5b respectively communicate with the chamber 7 surrounding the tubes. The connecting

flanges

4a, 4b, 5a and 5b are detachably connected with

other flanges

10a, 10b, 11a and 11b respectively, associated with

outer pipes

12a, 12b, 13a, and 13b respectively. The heat exchanger is mounted to turn on pivots 8 in bearings 9 in a frame, and the points of connection between the flanges are arranged in square formation in relation to one another in a plane perpendicular to the revolving axis and symmetrically in a circuit round this axis. Two heatexchanging media are conveyed through the outer pipes and flanged pipe connections to and from the heat exchanger through this respective pair of flange connections arranged diagonally opposite one another in the formation, one medium flowing through the two

pipes

12a and 12b and the other medium through the two

pipes

13a and 13b. It is assumed in the following that the direction of flow is from a to b in each pair of pipes, although item also be in the opposite direction in either or both pairs.

As a result of the symmetrical square grouping of all flanges around the pivot axis of the heat exchanger the latter can be connected to the outer pipes by means of these flanges in four dilferent turning positions of the heat exchanger, illustrated in Figs. 1, 3, 4 and 5 respectively.

In the turning position according to Fig. 1 the heat exchanging media will flow along the following courses: Medium 1; from the outer pipe line 12a through pipe line 2a, the tubes 6 downwards and through the pipe line 2b to the outer pipe 12b. Medium 2; from the outer pipe 13a through the pipe line 3a, the chamber 7 round the tubes and pipe line 3b to the outer pipe line 13b.

In the turning position according to Fig. 3, to the right in relation to the position according to Fig. 1, the courses will be as follows:

Medium 1; from the outer pipe line 12a through pipe line 311, the chamber 7 round the tubes and through pipe line 3b to the outer pipe line 12b.

Medium 2; from the outer pipe line 13a through pipe line 2b, the tubes 6 and the pipe line 2a to the outer pipe line 13b.

' Thus in this position the heat-exchanging media have changed courses with one another through the heat exchanger compared with the position according to Fig. 1, that is to say a so-called changed of passages has been effected. Moreover, the media pass through the tubes in the reverse direction, that is to say from pipe 2b to pipe 2a instead of in the opposite direction according to Fig. l.

' The same change of passages arises also in the turning position according to Fig. 4, 90 to the left in relation to that in Fig. 1, but here the medium through the space around the tubes passes in the opposite direction from pipe 3b to pipe 3a instead of in the oppostie direction according to Fig. 1.

In the turning position according to Fig. 4, finally, 180 in relation to that in Fig. 1, the pipes 211 and 2b, on one hand, and the pipes 30 and 3b, on the other hand, only have'exchanged places. There has been no change of passages. Both passage systems, on the other hand, are passed by the media in reverse direction, that is to say from pipe 2b to pipe 2a and from pipe 3b to pipe 3a respectively instead of in the opposite direction according to Fig. 1.

Starting from the position according to Fig. 1, the position according to Fig. 3 consequently implies a change of passages with reversed direction of flow in one passage system of the heat exchanger, the position according to Fig. 4 a change of passages with a reversal fiow in the second passage system of the heat exchanger, and the position according to Fig. 5 a reversed direction of flow in both passage systems without any change of passages.

With this arrangement it is therefore possible to run the heat exchanger with a periodical change of passages in combination with reversed flow in either of the two passage systems of the heat exchanger, or with periodical reversing of the flow simultaneously in both passage systerns.

Such an arrangement in heat exchangers of another type is exemplified by Figs. 6, 7 and 8. In principle it is analogous to the arrangement just described, as far as pipe-connections and the turning of the heat exchanger are concerned. The difi'erence is that the heat exchanger 1 is exchanged for a heat exchanger 1a of the crosscurrent type with plane heat transmitting walls 14, which form between them slot-

like passages

6a and 7a respectively for the heat-exchanging media. The

pipes

2a and 2b communicate with the passages 6a instead of with the passages 6 of the tube in the preceding example, and the

pipes

3a and 3b communicate with the passages 7a instead of with the space 7 round the tubes in this example. One medium is conveyed through the heat exchanger from pipe 12a to pipe 12b from above and downwards in the figure as shown by the dash-line arrow, and the second medium from pipe 13a to pipe 13b from left to right in the figure as shown by the full-line arrow.

In turningposition of the heat exchanger according to Fig. 6 the medium flowing in the direction of the dash-line arrow will pass through the passage 6a, and the medium flowing in the direction of the full-line arrow will pass through the passages 7a.

In the turning position according to Fig. 9, 90 to the right of the position in Fig. 6 (see character 15) a change of passages is effected in the same way as in turning of the heat exchanger 1 from the position in Fig. 1 to the position in Fig. 3, and in addition thereto the passage system 6a will be passed by the medium in the reverse direction to the case before the turning.

The same change of passages is efiected in the turning position according to Fig. 10, 90 to the left from the position in Fig. 6, and in addition the passages system 7a will be passed by the medium in the reverse direction to that before the turning.

Finally, in the turning position according to Fig. 11, 180 from the position in Fig. 6 there will be a complete turn round of the directions in which both passage systems are passed by the media without any change of passages.

Fig. 11 shows in addition how the connections between the outer pipes and the pipes which move together with the heat exchanger can be arranged in a radial instead of an axial direction as in the other figures. In this case the flanges have cylindrical connection surfaces with a radius equal to the distance to the turning axis of the heat exchanger so that the turning can be carried out without difiiculty, but other arrangements may be imagined, such as detachable spacing pieces, etc. Instead of flanges other types of pipe joints can of course be used.

When, as shown in the figures, the detachable pipe connections are arranged exactly symmetrically in square formation round the turning axis of the heat exchanger in one and the same plane at right angles to this axis, the parts of the heat-exchanger connections in each of the turning positions spaced at an angle of will occupy exactly exchanged positions. The outer pipe-lines can consequently be rigid and yet adapted to be connected in every such turning position.

If these pipe-lines are flexible, or in the extreme case consist of a hose or include a hose section, the requirement of an exact exchange of positions between the parts of connections of the heat-exchanger can, however, be more or less mitigated, that is to say large or small deviations may be made from the square formation, symmetry or the mutual plane individually or jointly without abandoning the possibility of connection in the different turning positions. The essential thing is that the detachable joints are arranged in their circuit around the turning axis in such a way that every second connection (in the square formation the diagonally opposite connections) connects an outer pipe for one medium to one of the passage systems of the heat exchanger and every second connection connects such a pipe for the other medium to the other passage system of the heat exchanger.

What I claim is:

Arrangement in indirect heat exchangers comprising in combination two separate passage systems for two heat exchanging media, a first inlet and a first outlet for one of said passage systems firmly connected to the heat exchanger and at opposite sides thereof, a second inlet and a second outlet for the other passage system firmly connected to the heat exchanger and at oppositely sides thereof, four detachable pipe connections for connecting the individual inlets and outlets, four in all, to one each of four pipes associated to an outer, fixed pipe system, two pipe lines of which are arranged to convey one medium and the other two pipe lines of which are arranged to convey the other medium to and, respectively, from the heat exchanger, said detachable pipe connections, facing in approximately one and the same Plane, being arranged in square formation as viewed against that plane and supporting means arranged to permit turning of the heat exchanger supported by said means around a revolving axis perpendicular to said plane.

References Cited in the file of this patent UNITED STATES PATENTS 2,508,119 Lockman May 16, 1950