EP0021007B1 - Device for separating cleaning bodies - Google Patents

Description

The invention relates to a device for branching discrete cleaning bodies carried in a fluid flowing through a tubular heat exchanger from the main flow of the fluid, consisting of a branch housing through which axial flow flows and a separating sieve device arranged therein with at least one sieve surface arranged obliquely to the flow a branch pipe ends, which is guided through the housing wall to the outside, the sieve surface being pivotable for cleaning purposes to such an extent that the sieve surface side previously located in the upstream direction comes to lie in the downstream direction and the sieve surface ends downstream near the housing wall and there a throat with the housing wall forms. Such a device is known from Japanese utility model 43-21002 / 1968.

A similar construction is also shown in US-A-4 135 574 and DE-B-2612905, which is parallel to it, although in these latter publications the separating screen cannot be pivoted within the housing.

However, the prior art has disadvantages. For example, both the US-A-4135-574 and DE-B-2 612-905, but also the Japanese utility model 43-21002 / 1968, always require a special design of the branch housing.

In DE-B-2 612 905 in particular, this results in a very high production outlay, since separation and welding work are cumbersome in order to achieve the required slots and swirl spaces, and the oblique cutting of the housing also impairs its compressive strength. In addition, in many cases an auxiliary water flow to produce the swirl effect is apparently required for proper functioning, see column 2, lines 49 to 52 of DE-B-2 612 905. This auxiliary water flow is shown in US Pat. No. 4,135,574 in FIG. 2 also drawn. Such an auxiliary water flow requires additional pump devices.

Due to the complicated pipe wall shape of the branch housing in the prior art, any plastic coating that may be required (e.g. with sea water as the heat exchange medium) is very difficult to apply.

The object of the invention is to improve the device according to the prior art in such a way that without the strength of the branch housing wall weakening slots the self-locking effect of cleaning bodies in the throat area between the branch housing wall and screen surface is eliminated.

This object is achieved in that in the area of the throat formed between the screen surface and the housing wall, a flat or curved edge plate (or kink) of the screen surface fastened to the housing wall or screen surface is provided, with the fillet angle between the edge plate (or kink) in the case of a flat edge plate. and the housing wall and / or between the edge plate (or kink) and the sieve surface is at least 90 ° and, in the case of a curved edge plate, the radius of curvature at the transition between the edge plate (or kink) and the housing wall and / or between the edge plate (or kink) and the sieve surface is greater than that half the diameter of the cleaning body is.

The possibly appropriate application of plastic coatings on the pipe wall is also possible without problems.

Advantageous further developments are proposed in the subclaims, so in claim 3 the arrangement of two screens to reduce the overall height of the device according to the invention, in claim 4 the rigid connection of these screens to reduce the number of actuation axes, which on the one hand simplifies the construction and on the other hand the number the required axis seals within the pipe wall are reduced.

In claim 6 it is shown that the screen surface, edge plate and housing wall expediently form a kind of funnel which opens at its narrower end on the branch connector, which in turn is guided through the housing wall to the outside. A second lower sieve can be arranged between this funnel end and the branch connector, which can be essentially funnel-shaped and is arranged in such a way that it forms a funnel continuation.

It may also be expedient to arrange this lower sieve (in the case of two or more discharge nozzles, there may also be more sieves) in accordance with claim 7, so that this sieve can also be cleaned by backwashing. In order not to have to pass a second actuation axis through the housing wall, a drive lever is articulated at one end at the narrow end of the lower sieve, the other end of which is connected to an inward projection of the free end of the upper sieve, such that that when the upper sieve is pivoted from the working position into the cleaning position, the lower sieve is also pivoted from the working position into the cleaning position. Alternatively, the lower sieve could also be rigidly connected to an associated upper sieve and pivotable with it, as stated in claim 9.

This would ensure that all screens of the arrangement, be it a lower and an upper screen or also several upper screens and one or more lower screens, each with only a single actuation axis for cleaning purposes, so that under certain circumstances only one Breakthrough would be arranged in the housing wall.

The already mentioned arrangement of 4 discharge ports, two each at the downstream end of each of the screen surfaces forming a roof, enables a further reduction in the overall length, in particular if lower screens are present. In addition, a pipe partition can be provided with four discharge ports, which divides the upper roof-shaped sieve into two halves, which increases the stability of the arrangement and also enables the actuating shaft to be additionally supported in this pipe partition.

By means of this additional storage, it is even possible to also divide the actuating shaft and to divide the entire arrangement into two branch halves which can be backwashed independently of one another.

Four, two “roofs” forming upper sieves can also be individually pivoted next to one another, the inner upper sieves opening in a lower, funnel-shaped sieve and opening into one (or more) discharge pipe. The lower screen could be rigidly connected to the adjacent screen surface and pivotable with it, or it could consist of several, e.g. there are two parts, one part being connected to an adjacent upper sieve, the other part being connected to the other upper sieve or also to the exhaust pipe or the housing wall.

The edge plate will usually consist of sheet metal, especially if the other parts of the device, such as the housing and / or sieve, are also made of metal, but it can of course also be e.g. be constructed from a plastic body, which is particularly useful if the device or parts thereof are also made of plastic.

The invention is explained in more detail below on the basis of exemplary embodiments which are illustrated in the drawings.

• Figur 1 einen schematischen Längsschnitt durch eine Vorrichtung zum Abzweigen von Reinigungskörpern mit dem erfindungsgemäßen Randblech, wobei diese Ausführungsform ein verschwenkbares Einzelsieb besitzt ;
• Figur 2 eine Dateilansicht des erfindungsgemäßen Randbleches ;
• Figur 3 eine ähnliche Konstruktion wie Fig. 1, jedoch mit zwei Abzweigstutzen und zwei zueinander dachförmig angeordneten Trennsieben ;
• Figur 4 eine ähnliche Konstruktion wie Fig. 3, jedoch mit einstückig angeordneten Sieben zwecks gemeinsamer Verschwenkung um nur eine Achse ;
• Figur5 eine Anordnung ähnlich der Fig.4, jedoch mit zusätzlich angeordneten und zusammen mit den oberen Sieben verschwenkbaren unteren Sieben ;
• Figur 6 eine schematische Draufsicht auf die Anordnung der Fig. 5 ;
• Figur 7 eine Anordnung der Fig. 5 in einer Stellung, in der die Siebe zur Rückspülung verschwenkt sind ;
• Figur 8 eine schematische Draufsicht auf eine Anordnung ähnlich der der Fig. 5, jedoch mit jeweils zwei trichterförmigen unteren Sieben auf jeder Seite zum Zwecke der Baulängenverkürzung ;
• Figur 9 eine Darstellung ähnlich der Fig. 8, jedoch mit zusätzlicher Rohrtrennwand ;
• Figur 10 eine Darstellung ähnlich der Fig. 6, jedoch mit verringerter Firstbreite des dachförmigen Siebes zur Vergrößerung des erreichbaren Schwenkwinkels ;
• Figur 11 eine Darstellung ähnlich der Fig. 3, jedoch mit vier oberen Trennsieben und mittig angeordnetem unteren Sieb ; und
• Figur 12 eine Darstellung ähnlich der Fig. 3, jedoch mit zusätzlich angeordneten und mit den oberen Sieben starr verbundenen unteren Sieben.

It shows :

• 1 shows a schematic longitudinal section through a device for branching off cleaning bodies with the edge plate according to the invention, this embodiment having a pivotable individual sieve;
• Figure 2 is a file view of the edge plate according to the invention;
• 3 shows a construction similar to that of FIG. 1, but with two branch connections and two separating screens arranged in a roof-like manner with respect to one another;
• FIG. 4 shows a construction similar to that of FIG. 3, but with sieves arranged in one piece for the purpose of joint pivoting about only one axis;
• Figure 5 shows an arrangement similar to Figure 4, but with additional arranged and pivotable together with the upper sieves lower sieves;
• Figure 6 is a schematic plan view of the arrangement of Fig. 5;
• Figure 7 shows an arrangement of Figure 5 in a position in which the screens are pivoted for backwashing;
• Figure 8 is a schematic plan view of an arrangement similar to that of Figure 5, but with two funnel-shaped lower sieves on each side for the purpose of shortening the overall length;
• FIG. 9 shows a representation similar to FIG. 8, but with an additional pipe partition;
• FIG. 10 shows a representation similar to FIG. 6, but with a reduced ridge width of the roof-shaped sieve in order to enlarge the achievable swivel angle;
• FIG. 11 shows a representation similar to FIG. 3, but with four upper separating sieves and a centrally arranged lower sieve; and
• FIG. 12 shows a representation similar to FIG. 3, but with lower sieves additionally arranged and rigidly connected to the upper sieves.

1 shows a particularly simple form of the device 10 according to the invention for branching off discrete cleaning bodies 1 from the main stream of a medium flowing through a heat exchanger, the flow of this main stream being indicated by the arrows 12. As already stated at the outset, the cleaning bodies 1 serve to free the tubes of the heat exchanger (not shown) from deposits, or to prevent their formation at all, so that the medium containing the cleaning elements causes the system to self-clean. The cleaning bodies usually consist of sponge rubber balls with a diameter that is slightly larger than the diameter of the heat exchanger tubes to be cleaned. Of course, other materials can also be used for the cleaning bodies, for example plastic foam material. It is only important that the cleaning bodies have approximately the same specific weight during operation as the heat exchange medium, so that undesired segregation processes do not occur. The branching device 10 according to the embodiment shown in Fig. 1 comprises a cylindrical branch housing 2, which advantageously has the same diameter as the line coming from the heat exchanger (not shown) to which the upper end (inlet end) of the branch housing 2 by means of a Flange connection 14 can be applied pressure-tight. The lower end (outlet end) of the housing 2 is also connected in a pressure-tight manner via a flange connection 16 to a line of the same diameter, which represents a continuation of the heat exchanger circuit.

To divert the cleaning elements 1 carried in the heat exchanger medium, a separating screen 3 is used, which is arranged in the axial housing at an angle to the flow 12 in such a way that the cleaning bodies 1 are guided in the direction of a branch pipe 4, from which they are drawn off by means of arrangements, not shown can. The The shape of the separating sieve 3 is elliptical in order to obtain an exact adaptation to the cylindrical housing wall of the branch housing 2. The separating sieve 3 has openings which are so small that the cleaning elements 1 cannot pass through the openings, even taking into account their flexibility. On the other hand, the permeability of the sieve should be so large that there is no significant impediment to the axial flow 12 through the sieve 3.

During the course of operation, foreign bodies can get caught on the sieve surface, which leads to an increase in flow resistance, which impair operation. In order to be able to remove these foreign bodies, the separating sieve 3 can be pivoted about an actuating shaft 5 into a backwashing position (not shown), in which the sieve surface 18 pointing in the upstream direction during normal operation comes into an outflow position, while at the same time the sieve surface 20 previously located in the downstream direction comes into the upstream position is coming. The flow directed through the sieve reverses its direction and flushes away the foreign bodies deposited on the surface 18. Then the sieve 3 is brought back into the normal position, which is shown in FIG. 1.

So that the fillet angle between the screen surface 18 and the inner wall surface of the branch housing 2 does not lead to jamming and deposition of cleaning bodies 1, a transition surface in the form of an edge plate 6 between the screen surface 18 and the inner housing wall 22 is now provided according to the invention such that between the on the upstream sieve surface 18 and on the upstream edge sheet metal surface on the one hand and between this edge sheet surface and the housing wall surface 22 on the other hand a too acute fillet angle is prevented. A fillet angle of at least 90 ° is selected. Such a fillet angle prevents with certainty that cleaning bodies 1 get stuck in the withdrawal area of the screen surface 18, see also FIG. 2, which shows this area in greater detail. The edge plate can be flat or curved, the radius of curvature being greater than the radius of the largest cleaning body to be branched off. The flat or curved transition surface in the manner specified can also be formed instead of an edge plate by kinking the sieve surface or by a curvature or fillet on the edge of the sieve surface (not shown).

The construction shown in Fig. 1 has the disadvantage that it has a relatively large length. 3 shows a construction which is improved in this respect and which, instead of only one separating screen 3, now has two separating screens with corresponding branch branches 4 and edge plates 6. The two separating screens 3 can be pivoted independently of one another about axes 5 and, in normal operation, are arranged such that they form a roof with a roof ridge 24 pointing in the countercurrent direction. Otherwise, the method of operation is quite analogous to that which has been described with reference to FIG. 1.

The arrangement of the axis 5 is expediently carried out so that the pressure created by the flow 12 and the flow resistance of the sieve 3 is divided equally between both lever arms of the sieve 3, so that essentially no flow about the axis 12 from the flow 3 onto the sieve 3 5 torque is created. The arrangement could also be chosen so that a low torque occurs in the direction in which the screen 3 is rotated into its working position, so that a kind of self-locking of the lever 3 is achieved in the working position. Because of the high flow velocities common today, a slight displacement of the axis 5 from the neutral position is sufficient to achieve the desired self-blocking effect, but on the other hand a change of the sieve 3 in the countercurrent flushing direction without applying large torques to the axis 5 while the medium is flowing through to enable.

As a comparison between FIGS. 1 and 3 shows, the arrangement of two screens allows a considerable shortening of the branch housing 2 with the same housing diameter. The disadvantage that is accepted is that two actuation axes 5 must be provided, which complicates the drive arrangement and also requires the arrangement of at least two breakthrough seals, which increases the susceptibility to maintenance. Fig. 4 shows another embodiment in which these problems are not present. For this purpose, the two individual sieves 3, which can still be seen in FIG. 3, are combined to form a roof-shaped sieve 30, in that the upper ends of the individual sieves 3 are firmly united and the lower ends are held apart by means of a strut 26. Due to the rigid connection of the two sieve parts 3 to a one-piece sieve 30, only a single axis 5 is required, around which the sieve construction 30 can be rotated for the purpose of backwashing. If the screen surface 18a is to be rinsed, the screen 30 is pivoted counterclockwise about the axis 5, to the extent that the surface of the screen 18a comes to lie in the downstream direction. Conversely, the screen 30 must be rotated clockwise if the screen surface 18b is to be cleaned by backwashing. The arrangement of the edge plates 6 is to be carried out in this construction in such a way that the sieve 30 can pivot past the edge plates 6. In addition, the fulcrum 5 must be placed so that the lower end 32 of the two partial screens 3 does not, or at least not yet, touch the inner wall of the housing 2 when the opposite partial screen 3 has just reached the rinsing position. The axis of rotation 5, which is expediently on the bisector of the two surfaces 18a, 18b, must not be too far from that of the two Surfaces 31 connecting imaginary line are distant, on the other hand, the pivot point must not be too close to this line to avoid too large a lever arm.

The construction shown in FIG. 4 also enables the attachment of so-called lower screens, which are advantageous in certain applications and are also already used in the prior art. 5 so that additional pivot axis bushings are not necessary due to the attachment of lower sieves, which should also be backwashable, a lever construction is provided according to FIG. 5, which also pivots when the upper sieve 30 is pivoted for the purpose of backwashing to pivot the lower sieves 32 accordingly leads to the backwash position.

Such lower sieves can also be provided in the construction according to FIG. 3, see FIG. 12, the lower sieves 32 being rigidly connected to the respective upper sieve 3 and being pivotable therewith for the purpose of backwashing. However, the backwash position for the lower sieves is somewhat less favorable here than in the construction shown in FIG. 5, but the arrangement is simpler for this.

In the embodiment shown in FIG. 5 (see also the illustration in FIG. 6) and also in the arrangement shown in FIG. 12, the screen surface 18a or 3 forms together with the inner wall 22 of the housing 2 and the surfaces of the two parts existing edge plate 6 a kind of funnel, which at its lower end merges into a second funnel, which is formed by the sieve surfaces 34 of the lower sieve 32 and by the inner wall 22 of the housing 2 and a further surface 36, which the two sieve surfaces 34 of the lower Siebes 32 supports. This surface 36 can be a closed plate or in turn a sieve surface. The outlet opening of the funnel formed by the lower sieve 32 opens into the discharge nozzle 4.

In the embodiment shown in FIGS. 5 and 6, the surface 36 which supports the sieve surface 34 is pivotally mounted at its one (upper) end via an axis 8, 38 which is suitably fastened to the inner housing wall, while at the other end the Surface 36 a lever 6 is articulated, the other end of which is articulated on a projection 40 of the screen 30. This link connection is made in such a way that when the screen 30 is pivoted by rinsing, for example, the screen surface 18a (see FIG. 7), at least one of the two lower screens (in FIG. 7 it is the lower screen 32b) may reach the backwash position. The other lower sieve (32a) reaches its backwashing position when the upper sieve 30 is pivoted into the washing position in which the sieve surface 18b is cleaned (not shown in FIG. 7).

The construction shown in Fig. 7, which consists of a roof-shaped upper sieve 30 and two funnel-shaped lower sieves 32, can thus be brought into the backwash position by a single pivot axis 5, with either a hand crank 43 being actuated for this purpose or a corresponding one machine drive, not shown, could take place.

It is important that only a single passage in the housing wall of the housing 2 is required to make this drive, while all other bearings can be realized by means of devices attached to the inner wall of the housing which do not require a passage and therefore do not result in any sealing problems.

It should also be pointed out that the surface 36 can have a projection 7 in order to form a rear partition for the discharge pipe 4 when the lower screen 32 is in the working position.

As can be seen in FIG. 6, the sieve surfaces 18a, 18b are not curved at their upper regions lying near the housing wall, but are made in a straight line and a further edge plate is used to close the opening between the edge of the sieve surface 18b and the housing wall 42 is provided so as to enable pivoting in both directions. The pivoting angle can be further increased if, according to FIG. 10, the width of the ridge 24 is reduced and the further edge plates 42 are widened accordingly, which could be necessary in particular with a steeper screen inclination in order to enable screen pivoting into the backwashing position.

As can still be seen from FIG. 7, the lower end of the screen surface 18a (FIG. 4 labeled 32) must be able to pivot freely downwards, which must be taken into account in the construction of the linkage, in particular the connecting lever 9.

The connecting lever 9 may have to have a corresponding curvature in order to allow the screen surface 18a to pivot downward.

A further shortening of the overall length, in particular when using funnel-shaped lower sieves, can be achieved if, according to FIG. 8, two discharge ports 4 are arranged on each side, each of which has its own funnel-shaped lower sieve 32, so that a total of four lower sieves 32 are present are.

This arrangement shown in FIG. 8 can still be removed according to FIG. 9 in that a partition 44 is provided perpendicular to the pivot axis 5 in such a way that it separates the two lower sieves 32 on each side and also the upper sieve 30 in two partial sieves 30a, 30b divides. This construction is particularly advantageous for larger pipe diameters. The illustration in FIG. 9 shows an embodiment with an additional bearing 46 for the shaft 5 in the partition 44, as a result of which the shaft 5 in the region of this bearing 46 could be divided into two shafts 5a and 5b which can be actuated independently of one another. Self a continuous shaft 5 with only one drive is understandably possible.

The construction according to FIG. 11 also shortens the overall length, in which four upper sieves 3 are arranged next to one another and in this way form two roofs. The two inner upper sieves 3i open into a lower sieve 32i which narrows downwards in a funnel shape in cross-section, at least in the direction of the pivot axes. Except for one side wall 50 is rigidly connected to an inner upper sieve 3i and can be pivoted with it, while the side wall 50 either with the other inner upper sieve 3i or, more simply, with the housing wall or with the exhaust pipe 4i for the lower sieve 32i collecting cleaning body can be connected.

Instead of edge plates 6, other arrangements can also form a transition surface between sieve 3 and housing wall 22, which prevent jamming of cleaning bodies, such as bulging of the inner tube wall, kinking of the sieve edge and the like. the like

Claims (18)

1. A device for separating from a main fluid flow discrete cleansing particles (1), carried along in a fluid flowing through a tubular heat-exchanger, said device consisting of a separator casing (2) through which an axial flow passes, and of a screen (3) located therein, with at least one screen surface (18) arranged obliquely to said flow, said surface (18) terminating at the downstream end in a branch nozzle (4) which passes outwards through the casing wall (22), the screen surface (18) being pivotable for cleaning purposes to such an extent that the side of the screen previously facing upstream now faces downstream, the screen surface (18) terminating on the downstream side in the vicinity of the casing wall (22), the screen surface (18) forming at that point a groove with said casing wall (22), characterised in that there is provided, in the region of the groove formed between the screen surface (18) and the casing wall (22), a planar or curved rim plate (6) fastened to the casing wall (22) or screen surface (18) (or bend in the screen surface (18)) ; when the rim plate is planar, the groove angle between rim plate (6) (or bend) and the casing wall (22) and/or between rim plate (6) (or bend) and screen surface (18) is at least 90° and, when the rim plate is curved, the radius of curvature at the transition between rim plate (6) (or bend) and the casing wall (22) and/or between rim plate (6) (or bend) and screen surface (18) is greater than half the diameter of the cleansing particles (1).

2. A device according to Claim 1, characterised in that the rim of the screen surface (18a, 18b) consists of rectilinear segments, and there are provided, between the rim of the screen surface and the casing wall (22), outwith the region of the branch nozzle, rim plates (6) attached to the rim of the screen surface.

3. A device according to Claim 1 or 2, characterised in that two screens (3) are provided, which form a roof configuration with the ridge facing contrary to the direction of flow.

4. A device according to Claim 3, in which the rim plate (6) is attached to the casing wall (22), characterised in that the two screens (6) are rigidly connected together, and are rotatable about a common axis (5), said axis lying substantially on the bisector of the angle formed by the two screen surfaces (18a, 18b).

5. A device according to Claim 4, characterised in that the free ends (32) of the screens (3) which are arranged at an angle to one another, are connected together by braces (26) which support the axis (5).

6. A device according to one of Claims 1 to 5, in which screen surface (18), rim plate (6) and casing wall (22) form a hopper opening at its lower end into the branch nozzle (4) which passes outward through the casing wall, characterised in that there is located between the end of the hopper and the branch nozzle (4), a lower, substantially funnel-shaped screen (32), forming a continuation of the hopper, and its outlet end opening into the branch nozzle (4).

7. A device according to Claim 6, characterised in that the wider end of the lower screen (32) is mounted to pivot about an axis (38) attached to the casing wall and lying parallel to the pivotable axis (5) of the upper screen (3 ; 30).

8. A device according to Claim 7, characterised in that, at the narrow end of the lower screen, there is articulated by one end a drive lever (9), whose other end is connected to an inwardly- directed lug (40) on the free end of the upper screen (3, 30) in such a way that, when the upper screen is pivoted from its operational position into the cleaning position, the lower screen (32) also pivots from its operational position into the cleaning position.

9. A device according to Claim 6, charactetiseõ" in that the lower hopper-shaped screen (32) forms a rigid unit with the upper screen (3), and is pivotal along therewith (e.g. Fig. 12).

10. A device according to one of Claims 3 to 9, characterised in that there are provided, at the downstream end of each of the screen surfaces (18a, 18b) forming a roof configuration, two branch nozzles (4) respectively.

11. A device according to Claim 10, characterised in that a hopper-shaped lower screen (32) is provided for each branch nozzle (4).

12. A device according to Claim 10 or 11, characterised in that a tube partition wall (44) divides the upper roof-shaped screen into two screen halves (30a, 30b).

13. A device according to Claim 12, characterised in that the partition wall (44) has a bearing (46) for the actuating shaft (5).

14. A device according to Claim 13, characterised in that the actuating shaft (5) is divided in the region of the bearing (46), resulting in two independent rotatable actuating shafts (5a, 5b) for independent back-rinsing of the upper screen halves (30a, 30b) and if necessary of the lower screens (32).

15. A device according to one of Claims 1 to 2, 5 to 6, 9 to 10, 12 to 14, characterised in that, in all, four individual screen surfaces (18) are provided, and form a roof configuration during the separating operation, the two inner screen surfaces (18d, 18c) opening into a second screen (32i) having a hopper-like profile in the pivotal axis direction and having, vertically thereto, a hopper-like or rectangular profile, the end of the hopper opening into a branch nozzle (4i) for the cleansing particles.

16. A device according to Claim 15, characterised in that the second screen (32i) is rigidly connected to one of the screen surfaces (18c).

17. A device according to Claim 15, characterised in that the second screen (32i) is rigidly connected to the branch nozzle (4i).

18. A device according to Claim 15, characterised in that the second screen (32i) is in several parts, one part being connected to one inner screen surface (18c), and other parts (e.g. 50) being connected to the other inner screen surface (18d), the branch nozzle (4i) or the casing wall (22).

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