AU600356B2 - A flow equalization device - Google Patents

Description

AU-AI-15400/88 P T WORLD INTELLECTUAL PROPERTY ORGANIZATION PCT nternq,"*na1 R ."u INTERNATIONAL APPLICATION PB I D DE H5 TE6 COOPERATION TREATY (PCT) (51) International Patent Classification 4 (11) International Publication Number: WO 88/ 07231 7/01 Al (43) International Publication Date: 22 September 1988 (22.09,88) (21) International Application Number; PCT/AU88/00079 (81) Designated States: AT (European patent), AU, BE (European patent), CH (European patent), DE (Euro- (22) International Filing Date: 18 March 1988 (18.03.88) pean patent), FR (European patent), GB (European patent), IT (European patent), LU (European patent), NL (European patent), SE (European patent), US.

(31) Priority Application Number: PI 0986 (32) Priority Date: 20 March 1987 (20.03.87) Published With international search report.

(33) Priority Country: AU (71)(72) Applicant and Inventor: PAIN, John, Ronald [AU/ AU]; Bannons Lane, Yarrambat, VIC 3091 (AU).

7 NOV 1988 (74) Agents: PRYOR, Geoffrey, C. et al,; Davies Collison, I Little Collins Street, Melbourne, VIC 3000 (AU).

AUSTRALIAN

OCT i988 PATENT

OFFICE

(54) Title: A FLOW EQUALIZATION DEVICE (57) Abstract A flow equalization device for equalizing flow between an inlet and two outlets (16, 18). The device includes a slidable orifice plate assembly (40) which Is normally centrally located so that flow from the outlets (16, 18) is equal. When however there is a pressure build up in one of the outlets, the assembly (40) will move so as to restore equal flow from the outlets (16, 18), i i p -i WO 88/07231 PCT/A U88/00079 1 A FLOW EQUALIZATION DEVICE The present invention relates to a flow equalization device particularly adapted to divide ar: inlet stream of fluid into two discharge streams at substantially equal flowrates.

One known device for dividing an inlet stream of fluid into two outlet streams comprises a tee piece having a single inlet and two outlets. A disadvantage with the tee piece is that it is not adapted to compensate for changes in fluid pressure downstream of the tee piece which cause differences V "in the flowrates in the outlet streams. This is a SUBSTITUTE

SHEET

T9 WO 88/07231 PCT/AU88/00079 2 particularly significant disadvantage when the tee piece is used to divide the flow of non-Newtonian fluids to parallel tube heat exchangers used in the food processing industry. In such situations it is important that there be equal flowrates of fluid through each of the heat exchangers in the parallel tube heat exchangers. With the use of the tee pieces variations of pressure within the heat exchangers causes differences in flowrates through the outlets to the heat exchangers. Rather than being self regulating the pressure imbalances between the heat exchangers tend to increase until eventually the majority of the flowrate through the tee piece is diverted through one outlet and heat exchanger and the other heat exchanger shuts down.

An object of the present invention is to at least alleviate the disadvantage of the prior art outlined in the preceding paragraphs.

According to the present invention there is provided a flow equalization device comprising: a housing defining a chamber,a fluid inlet through which fluid may be introduced into said chamber, first and second fluid outlets through which fluid may be discharged from said chamber at respective predeterm$.Jed flowrates, and flow equalization means within the chamber, said means being responsive to changes in pressure, in use, downstream of either one of the fluid outlets, which pressure change varies the flowrates to the predetermined flowrates.

n WO 88/07231 PCT/A U88/00079 3 Preferably the pressure responsive means comprises, an orifice plate positioned across each outlet, each orifice plate having an orifice through which fluid may flow from said chamber at the respective predetermined flow rate, said orifice plates being interconnected and movable within said chamber in response to pressured changes downstream of said orifice plates, the flow equalization means responsive to movement of said orifice plates to vary the flow of fluid to said orifice plates, whereby a change in pressure downstream of one of said orifice plates varies the flow rate of fluid from both said fluid outlets from said predetermined flow rates and causes said orifice plates to move within said chamber such that said flow equilization means increases the flow of fluid to the one orifice plate and reduces the flow of fluid to the other orifice plate thereby to restore the flow rate of the fluid through said fluid outlets to the predetermined flows rates.

Preferably the orifice in each orifice plate in use promotes turbulent flow in the fluid.The present invention also provides a parallel tube heat exchanger system comprising a plurality of tube heat exchangers arranged in parallel, and at least one device, described in the foregoing connecting the heat exchangers to a single feed supply of fluid.

Further detailed description of a preferred embodim ent of the device of the present invention and a parallel tube heat exchanger system of the present invention incorporating the valve assembly is provided with refcerence to the following drawings in 7 WO 88/07231 PCT/AU88/00079 4 which: Figure 1 is a longitudinal section through a flow equalization device formed in accordance with the present invention, Figure 2 shows the device with the orifice plate assembly is a different position, and Figure 3 is a schematic view illustrating a parallel tube heat exchanger incorporating the device shown in Figures 1 and 2.

The flow equalization device illustrated in Figures 1 and 2 comprises a cylindrical housing 4, which is formed with a spigot 6 which functions as a fluid inlet 8 for communication with an inlet chamber The device includes end plates 12 and 14 and four tension bolts 13 which are clamped against end faces of the housirg 4, The end plates 12 and 14 include centrally located outlet openings 16 and 18 which are surrounded by a outlet spigots 20 and 22 for coupling to pipe work or other equipment (not shown), Axially disposed within the housing 4 is a spindle 24 which includes first and second recesses 26 and 28 extending inwardly from opposite ends of the spindle. The ends of the spindle 24 are clamped against the end plates 12 and 14, O-rings 28 are located in recesses in end faces of the housing 4 to seal against the plates 12 and 14. 0-rings 30 are located in annular recesses in the ends of the spindle 22 so as to also seal against the plates 12 and 14. The spindle 22 includes a pair of axially I ;I -c -i 1 WO 88/07231t PCT/A U88/00079 extending slots 32 and 34 which communicate respectively with the recesses 24 and 26. The slots 32 and 34 provide fluid communication between the recesses 24 and 26 and respective end chambers 36 and 38.

The device includes an orifice plate assembly 40 which is slidably mounted on the spindle 22, The assembly 40 includes a hollow shaft 42 which is mounted on the spindle 22. Orifice plates 44 and 46 are located at respective ends of the tube 42. The plates 44 and 46 includes orifices 48 which provide fluid communication between the central chamber and the end chambers 36 and 38. The size and number of the orifice chambers 48 is the same in both plates so that provided there are no obstructions, flow into the inlet 8 will be equal through the orifices 48 and hence through the respective outlet openings 16 and 18.

In operation if the spigot 6 is connected to an inlet conduit, flow into the inlet 8 will be split uniformly between the outlets 16 and 18, owing to the symmetry of the arrangement. If however one of the outlets is obstructed either internally of the device or downstream in the conduits connected to the outlets, the orifice plate assembly 40 will operate so as to tend to equalize the flow between the outlets 16 and 18. Assume for instancG that the conduit coupled to the outlet 16 becomes partially obstructed, the flow through the orifices 48 in the plate 44 will initially tend to decrease hence the pressure drop across that plates will decrease compared to the pressure drop across the orifices in I_ _I WO 88/07231 PCT/ALU88/00079 6 the plate 46. As a consequence, the resultant forces acting against the plate 46 are greater than those acting against the plate 44 which causes the assembly to move towards the right, as shown in Figure 1.

This movement causes the slots 34 to be progressively reduced in their effective size for fluid communication between the central chamber 10 and the end chamber 38. At the same time, the slots 32 at the other end of the spindle will be puogressively opened so as to increase the effective size of the slots for communication between the chambers 10 and 36. This has the effect of impeding flow from the outlet 18 and increasing the flow through outlet 16. Movement of the assembly 44 continues until once again the flow rates from the outlets 16 and 18 are substantially restored to equilibrium.

Many modifications to this arrangement are possible. For instance alternative arrangements are disclosed in the specification of application no. PI 0986/87, the disclosure of which is incorporated herein by cross reference.

In illustrated arrangement, provision is made for in situ cleaning of the device. In this respect shaft 42 includes a pair of openings 50 which communicate with the interior of the shaft. The spindle 22 includes pairs of openings 52 and 54 which open into the respective recesses 24 and 26. In the central position of the device, as shown in Figure 1, there would be relatively minimal flow of fluid through the openings 50 into the openings 52 and 54 owing to the relatively close tolerance between the inner diameter of the shaft 'i2 and the spindle 22 WO 88/07231 PCT/A1L88/00079 7 (for instance .2mm). When however the assembly 40 is moved fully to the left, as shown in Figure 2, the openings 50 aligned with the openings 52 so that a purging or cleaning fluid can be passed from the inlet 8 to the oi.ulet 16 (and connected passages) so as to clean that part of the device. A similar effect can be achieved by moving the assembly 40 fully to the right so as to align the openings 50 with the openings 54. Mechanical, electrical or pressure operated means could be provided to move the assembly to one or other of its positions for cleaning.

The device 2 is particularly suited for use in the food pocessing industries as a flow divider for feeding non-Newtonian fluids, such as orange pulp or tomato paste, to parallel heat exchangers. In one arrangement, shown diagramatically in Figure 3, orange pulp is forced at a constant flowrate from a supply 33 by a positive displacement pump 35 into the inlet 8 of the device. The device divides te orange pulp into two streams discharging from the outlets 16 and 18 at equal flowrates into the parallel heat exchangers 35a, 35b, The exchanges have heat transfer fluid inlets 37 and outlets 39. The streams of orange pulp discharging from the heat exchangers 35a, are recombined into a single stream for further processing as required.

The device 2 has been found to be successful in maintaining equal flowrates of orange pulp and tomato paste to each heat exchanger notwithstanding variations in pressure conditions within the heat exchangers. The device has been found to be responsive to minor changes in pressure with the heat

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WO 88/07231 PCT/AU88/00079 8 exchangers to equal flowrates through each of the heat exchangers. In this regard, it has been found that the response of the device to pressure changes is improved by constructing the orifice plates to be large in cross-section compared to the cross-sectional area of the shaft and by selecting the parameters of the orifices to promote turbulent flow of orange pulp from the central chamber through the orifices, Furthermore, the device tends to automatically clear blockages of the orifices. In this regard, in the event that fibrous materials in the orange pulp blocks the orifices in one of the annular plates the flow will be momentarily stopped resulting in movement of the assembly 40 to increase the flow path and thus assist to pass the plug of fibrous material Many modifications will be apparent to those skilled in the art without departing from the spirit and scope of the invention,

I

Claims (9)

1. A flow equilization device comprising a housing having an inlet which communicates with a chamber (10,36,38) first and second fluid outlets (16,18) from the chamber, flow equilization means (40,32) within the chamber, said means being responsive to changes in pressure, in use, downstream of said outlets (16,18) and being operable to partially restrict the fluid flow path to one or other of the outlets to thereby substantially maintain equal flow rates from the outlets.

2. A device as claimed in claim 1 wherein said flow equilization means comprises an orifice plate assembly said assembly comprising first and second plates (44,46) connected together by connecting means each plate including at least one orifice said assembly (40) being slidably moveable in said chamber.

3. A device as claimed in claim 2 wherein the chamber includes an inlet chamber (10) which is located generally between the plates (44,46) and first and second outlet chambers (36,38) which are located adjacent to the first and second plates and communicate with the first and second outlets respectively, the orifice plate assembly being operable, when one of the outlets chambers has increased pressure therein, to move away from the outlet of said one outlet chamber.

4. A device as claimed in claim 3 wherein the connecting means comprises a shaft (42) and movement II -T WO 88/0)7231 PCT/A U88/00079 thereof causes variations in the fluid flow paths from the inlet to the first and second outlets, A device as claimed in claim 4 wherein including a spindle (22) which extends through said chambers (10,36,38), the spindle including first and second, recesses (24,26) which communicate with the first and second outlets respectively said spindle including first and second openings (32,34) which provide fluid communication between the first and second recesses (24,26) and first and second outlet chambers (36,38) respectively and wherein said shaft (42) is hollow and is mounted for sliding movement on said spindle (22).

6. A device as claimed in claim 5 wherein the first and second openings comprise slots (32,34) which extend axially of the spindle the arrangement being such that the position of the Soriice plate assembly (40) varies the effective size Of the slots (32,34) which provide the fluid flow paths from the first and 'second outlet chambers to the first and second outlets respectively,

7. A device as claimed in claim 5 or 6 wherein the housing comprises a hollow cylindrical body (4) and first and second and plates (12,14) which include the first and second outlets.

8. A device as claimed in claim 7 including tension bolts (13) which extend between the end plates and clamp the hollow cylindrical body therebetween. I 7 WO 88/07231 PCT/AU88/00079

9. A device as claimed in claim c in 0-rings (28,30) are provided in the end es of the hollow cylindrical body and spindle to seal against the end plates. A device as claimed in claim 5, 6, 8 or 9 including first and second cleaning openings (52,54) which communicate with the inner ends respectively of the first and second recesses (24,26) and wherein the said hollow shaft (42) includes at least one third cleaning opening (50) which can be selectively aligned with the first and second clearing openings for passage of a cleaning fluid,

11. A flow equilization device as claimed in any preceding claim in combination with first and second heat exchangers (35a,35b) coupled to the first and second outlets (16,18) respectively, 61M.-