WO1999031441A1

WO1999031441A1 - Venturi apparatus for flow control

Info

Publication number: WO1999031441A1
Application number: PCT/US1998/026476
Authority: WO
Inventors: James L. Mckenney
Original assignee: Jandy Industries, Inc.
Priority date: 1997-12-15
Filing date: 1998-12-14
Publication date: 1999-06-24
Also published as: AU1912599A

Abstract

A venturi apparatus (10) includes a venturi (12) mounted to a plurality of interconnecting conduits (14, 16, 18). The interconnecting conduits include a source conduit (14), an output conduit (16) and a bypass conduit (18). The three conduits (14, 16, 18) meet at a common juncture (20), and the venturi (12) projects into the juncture (20). In one embodiment, the venturi apparatus (10) is incorporated into a heating system (40) which also includes a boiler (46) connected to the source conduit (14) and a pump (44) in the source conduit (14) which draws water from a source (42) through the boiler (46). In this system (40), the venturi (10) permits the control of fluid flow both by permitting flow from the bypass conduit (18) through the output conduit (16) when flow through the output conduit (16) is high and by permitting flow from the inlet conduit (14) through the bypass conduit (18) when flow through the output conduit (16) is low.

Description

TITLE VENTURI APPARATUS FOR FLOW CONTROL

INVENTOR James L. McKenney, a U.S. citizen, residing at 35 Norwell Avenue, Norwell, Massachusetts 02061.

CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority from United States provisional patent application serial number 60/069,635, filed on December 15, 1997.

FEDERALLY SPONSORED RESEARCH Not Applicable.

BACKGROUND OF THE INVENTION

Boiler-based home heating systems are commonplace. Often, the system is designed to provide heat for both domestic hot water and domestic space heating systems. To enable these dual uses, the source conduit, which supplies water from the boiler, is connected to a forked junction. At this junction, a pair of conduits diverge. One leads to a space heating system. The other leads to heat exchanger for a domestic hot water system. Conventional valves are used to control the flow distribution between these two conduits.

DISCLOSURE OF THE INVENTION

Prior art heating systems typically lack a flow control mechanism that will accommodate both low flow and high flow through the outlet to the space heating system while preventing excessive demand of water through the boiler at high flow and providing a bypass conduit for an excess supply of water during high demand. The apparatus of this invention accommodates this need with an absence of moving parts or complicated machinery, making it relatively failsafe. A venturi apparatus includes a venturi mounted to a plurality of interconnected conduits. The interconnected conduits include a source conduit, an output conduit, and a bypass conduit, each meeting at a common juncture. The bypass conduit joins the juncture between the source conduit and the output conduit, and the venturi projects into the juncture. The assembly is such that fluid flow is permitted through the venturi and out the bypass conduit when fluid flow in the output conduit is low and through the bypass conduit and out the output conduit when fluid flow in the output conduit is high.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of the invention will be apparent from the following, more particular description of preferred embodiments of the invention, as illustrated in the accompanying figures. The drawing is not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Figure 1 is a cross-sectional view of a venturi apparatus of this invention.

Figure 2 is a schematic illustration of a home heating system incorporating a venturi apparatus.

Figure 3 is a schematic illustration of a boiler heating system incorporating a venturi apparatus.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The features and other details of the method of the invention will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. Numbers that appear in more than one figure represent the same item. It will be understood that the particular embodiments of the invention are shown by way of illustration and not as limitations of the invention. The principle features of this invention can be employed in various embodiments without departing from the scope of the invention.

Figure 1 illustrates an embodiment 10 of a venturi apparatus for controlling fluid flow. The venturi 12 is mounted at a juncture 20 of a source conduit 14, output conduit 16 and bypass conduit 18. The volume within the juncture 20 of the source conduit 14, output conduit 16 and bypass conduit 18 is designated 20. As shown, the venturi 12 has the shape of a tapered cylinder, wherein the inlet 22 has a larger circumference than the outlet 24. The inlet 22 of the venturi 12 is mounted at the joining end 26 of the source conduit 14. From here, the venturi 12 projects into the juncture 20. The bypass conduit 18 is attached to both the source conduit 14 and the output conduit 16. While the source conduit 14 and output conduit 16 are aligned along a common axis, the bypass conduit 18 projects along an axis perpendicular to that of the source conduit 14 and output conduit 16. Because the venturi 12 projects only partially across the juncture 20, fluid flow is attainable from the source conduit 14 into the bypass conduit 18 as well as from the bypass conduit 18 into the output conduit 16.

In the embodiment shown in Figure 1, the bypass conduit 18 and output conduit 16 are joined as an integral module. The venturi 12 has a flange 28 sized to match a notch 30 within this module. Accordingly, this embodiment 10 is assembled by inserting the venturi 12 into a first end of the module and sliding it through until it abuts the notch 30. The source conduit 14 follows the venturi 12 into the module and pins the venturi 12 against the notch 30.

The venturi apparatus 10 can be incorporated into a variety of fluid-flow systems. The venturi apparatus 10 is particularly useful in a boiler heating system, such as that illustrated in Figure 2. In system 40, a source of water is stored in a storage tank 42. The storage tank 42 acts as a heat sink extending the amount of energy stored within the boiler system 40.

A pump 44 is joined with an outlet of the storage tank 42. The pump 44 is used to pump water from the storage tank 42 to the boiler 46. The boiler 46 is of the type disclosed in U.S. Patent 4,222,350, issued to Pompei, et al., which is hereby incorporated by reference. A distinction between the boiler 46 of Figure 2 and that of the above-referenced patent, however, is that the outlet from the boiler 46 in the above-referenced patent extends from the boiler 46, back down to the storage tank 42. In the embodiment shown in Figure 2, the outlet from the boiler 46 extends upward, away from the storage tank 42 to separate water distribution conduits. The boiler 46 is fueled with natural gas or propane from a gas line 48. A blower 50 feeds the fuel from the gas line 48 into the boiler 46. After a mixture of air and the fuel combust in the boiler 46 to produce heat, the exhaust gases are released through a flue 52.

A series of temperature sensors 54, 56 and 58 are positioned in the line 59 joining the storage tank 42, pump 44 and boiler 46. Each of the temperature sensors 54, 56 and 58 communicate with a controller 60 for controlling the system. The first sensor 54 is positioned in the storage tank 42, where it measures the temperature of the water within the storage tank 42. These measurements are fed to the controller 60 which compares the measured temperature with a trigger value. If the measured temperature is below the trigger value, i.e., the water is too cold, the controller 60 sends a signal to a heater within the storage tank 42 to heat the water. When the measured temperature reaches an upper limit, the controller 60 sends a signal to the heater to shut it off.

The second temperature sensor 56 is positioned between the pump 44 and the boiler 46. The second sensor 56 measures the temperature of the water as it is fed to the boiler 46 and sends the measurement to the controller 60. The controller 60 evaluates this measurement to determine how much heat needs to be supplied by the boiler 46. If the temperature of the water entering the boiler 46 drops, the controller 60 sends s signal to the blower 50 to increase the rate at which fuel is fed to the boiler 46. If the temperature increases, the controller 60 slows the blower 50 to decrease the rate at which fuel is fed to the boiler 46. The third temperature sensor 58 is positioned after the boiler 46. The third sensor 58 likewise transmits its temperature measurements to the controller 60. The controller 60 monitors signals from the third sensor 58 to determine if an upper limit is exceeded so as to prevent overheating. In a preferred embodiment, where water is passed through the system 40, the upper limit is 195°F. If this limit is exceeded, the pump 44 and the blower 50 are shut down to stop the system 40.

After the third sensor 58, the line 59 is bifurcated into a heat-exchange conduit 62 for a domestic hot- water heat-exchanger 66 and a source conduit 14 for a central (or space) heating system 82.

Flow through the heat-exchange conduit 62 is controlled by a first zone valve 64. The first zone valve 64 opens only when hot water is needed. A plate heat exchanger 66 provides the mechanism for transferring heat to a domestic hot water supply circuit 68. After passing through the plate heat exchanger 66, the water within the heat-exchange conduit 62 is directed back to a return line 88 which recycles the water back to the storage tank 42.

Within the domestic hot water supply circuit 68, cold water flows through a supply line 70 to a flow switch 72. The flow switch 72 regulates the rate of flow of water from the supply line 70. From the flow switch 72, the supply line 70 is bifurcated to a bypass conduit line 74 and a line 76 through the heat exchanger 66. Water flowing through the bypass conduit 18 remains cold, while water flowing through the heat-exchanger line 76 is heated with heat exchanged from boiler-heated water in the heat exchange conduit 62. Both of the lines 74 and 76 are connected to a thermostatic mixing valve 78. The thermostatic mixing valve 78 is set to achieve the desired balance of water from each of the lines 74 and 76 to achieve a composite flow of water having the desired temperature, for example 120°F. An outlet line 80 receives the composite flow from the thermostatic mixing valve 78 and delivers the hot water to either a hot water tank or directly throughout the home Meanwhile, the source conduit 14 circulates water to a space heating system 82. The source conduit 14 connects with a venturi 12. The venturi 12 is directed toward an output conduit 16, and a bypass conduit 18 projects radially from the venturi 12 at the junction of the source conduit 14 and the output conduit 16. The output conduit 16 is connected to a space heating system 82. In one embodiment, the space heating system include a plurality of zone heaters, each in a line branching from the output conduit 16. The zone heaters may be equipped with pumps, or a single pump and separate valves, which draw fluid through the output conduit 16, or they may only include valves, with hot water being driven through the zones by the pump 44.

When demand is low or where the heaters within the heating system 82 are shut down, flow through the output conduit 16 is slowed. Flow within the central heating system 82 can also be stopped by closing a second zone valve 83. If the boiler 46 and pump 44 are operating, water is directed from the source conduit 14, through the venturi 12 and into the bypass conduit 18. The bypass conduit 18 is connected to a recycle line 84, where the water joins with that fed from the central-heating outlet 86. The recycle line 84, in turn, is connected to the return line 88 completing a circuit for returning the water to the storage tank 42.

When demand is high and the second zone valve 83 is open, the space heating system 82 may draw water at a rate faster than that at which the pump 44, by its own accord, is sending water to the boiler 46. The venturi apparatus 10 enhances water distribution under these conditions. High water demand in the space heating system 82 will cause a pressure differential among the conduits 14, 16 and 18. When the pressure in the output conduit drops low enough, water will be drawn not only from the source conduit 14 but also from the bypass conduit 18, causing the water within the bypass conduit 18 to flow in a direction reverse from that when demand is low. Figure 3 illustrates a second boiler heating system 100. A boiler 46 for heating the water is connected to a source conduit 14 for distributing the heated water from the boiler 46 to an indirect water heater 66 and a zone heating system 82. The bypass conduit 18 connects with an indirect water heater 66. The source conduit 14 connects with a venturi apparatus 10 with the output conduit 14 feeding to a network of zone space heaters 82. The output conduit 14 branches into a plurality of zone heating lines 102, each controlled with a valve 104.

When the valves 104 are open, a pump 44 drives water from the boiler 46, through the venturi 12, through the output conduit 16 and into the zone heating lines 102. Alternatively, pumps may be placed in the zone heating lines 102 to draw water from the boiler 46. A recycle line 102 is connected with the outlets of the zone heating lines 102. At its opposite end, the recycle line 84 connects with a return line 88, completing a circuit from the boiler 46, through the zone heating system 82 and back to the boiler 46. A pump 44 is placed in the return line 88 to feed the water back through the boiler 46.

When the valves 104 are closed, water flows from the boiler 46, through the venturi 12 and through the bypass conduit 18. The bypass conduit 18 connects with an indirect water heater 66, where heat is transferred from the water entering from the bypass conduit 18 to water in a separate domestic water circuit 68, thereby providing hot water for domestic use. The bypass conduit then connects with the return line 88. Accordingly, when the valves 104 are closed, the flow of water cycles through the bypass conduit 18, through the indirect water heater 66 and back to the boiler 46. Unlike the system 40 illustrated in Figure 2, the system 100 of Figure 3 is not designed to provide fluid flow in a reversed direction from the bypass conduit 18 to the venturi 12. The direction of flow from the venturi 12 is governed by an aquastat within the indirect water heater 66. The aquastat monitors the temperature of the water in the heater 66. If the temperature is too low to provide the desired heat to the domestic water supply 68, the zone valves 104 are closed to stop the flow of water through the output conduit 16 and redirect it through the bypass conduit 18. When the temperature reaches an upper limit, the aquastat reopens the valves 104 to slow or stop the flow of water from the venturi 12 to the bypass conduit 18.

While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention as defined by the appended claims.

Claims

CLAIMSI claim:

1. A venturi apparatus (10) for flow control comprising: a venturi (12) having an inlet (22) and an outlet (24); and a plurality of interconnected conduits including: a source conduit (14) extending from the venturi inlet (22); an output conduit (16) extending from the venturi outlet (24); a bypass conduit (18) between the source conduit (14) and the output conduit (16), wherein the bypass conduit (18) both permits fluid flow through the venturi (12) and out the bypass conduit (18) and permits fluid flow from the bypass conduit (18) into the output conduit (16); and a juncture (20) joining the source conduit (14), the output conduit (16), and the bypass conduit (18), wherein the venturi (12) is mounted to the plurality of interconnected conduits (14, 16, 18) and projects into the juncture (20).

2. The venturi apparatus (10) of Claim 1, wherein the venturi (12) has an exterior shell extending from the inlet (22) to the outlet (24), and the bypass conduit (18) extends in a substantially-radial direction from the exterior shell of the venturi (12).

3. The venturi apparatus (10) of Claim 2, wherein the source conduit (14) and the output conduit (16) extend from the venturi (12) along a common axis.

4. The venturi apparatus (10) of Claim 3, wherein the source conduit (14) is connected to a fluid source (42).

5. The venturi apparatus ( 10) of Claim 4, wherein the output conduit ( 16) is connected to a heating appliance (82).

6. The venturi apparatus (10) of Claim 5, wherein the bypass conduit (18) provides a passage from the outlet (24) to the fluid source (42).

7. A venturi apparatus (10) for flow control comprising: a venturi (12) having an inlet (22) and an outlet (24); and a plurality of interconnected conduits including: a source conduit (14) extending from the venturi inlet (22); an output conduit (16) extending from the venturi outlet (24); a bypass conduit (18) between the source conduit (14) and the output conduit (16), wherein the bypass conduit (18) both permits fluid flow through the venturi (12) and out the bypass conduit (18) and permits fluid flow from the venturi (12) and out the output conduit (16) depending on pressure within the output conduit (16); and a juncture (20) joining the source conduit (14), the output conduit (16), and the bypass conduit (18), wherein the venturi (12) is mounted to the plurality of interconnected conduits (14, 16, 18) and projects into the juncture (20).

8. A heating system (40) comprising: a water source conduit (14); a boiler (46) feeding into the water source conduit (14); a pump (44) in the water source conduit (14) which draws water from a source (42) through the boiler (46); an output conduit (16); a bypass conduit (18) between the output conduit (16) and the water source conduit (14); and a venturi (12) at the intersection of the bypass conduit (18) and the output conduit (16) positioned such that flow from the boiler (46) to the output conduit (16) draws liquid from the source conduit (14) in a first direction through the bypass conduit (18) with high flow through the output conduit (16) but permits recirculation through the bypass conduit (18) in an opposite direction with no flow through the output conduit (16).

9. A method of controlling a fluid flow through a closed system (40) that includes a fluid-receiving apparatus (82) that has a supply conduit (14, 16) that is in fluid communication with a discharge port of a pump (44) and a return conduit (84, 86) that fluidly communicates with an intake port of the pump (44), the system (40) further including a bypass conduit (18) extending between the supply conduit (14, 16) and the return conduit (84, 86) to facilitate fluid flow between the supply conduit (14, 16) and the return conduit (84, 86), said method comprising: pumping an output of fluid from the pump (44) into the supply conduit (14, 16); and restricting the supply conduit (14, 16) at a juncture (20) wherein the bypass conduit (18) adjoins the supply conduit (14, 16) such that when the fluid-receiving apparatus (82) requires a flow of fluid that exceeds said fluid output of the pump (44), fluid is drawn into the supply conduit (16) through the bypass conduit (18) and when the fluid-receiving apparatus (82) requires a flow of fluid that is less than said fluid output of the pump (44), at least some of said fluid output flows through the bypass conduit (18) to the return conduit (84).

10. The method of claim 9, wherein said restricting further comprises gradually reducing an inside diameter of the supply conduit (14, 16) at the juncture (20).

11. The method of claim 10, wherein the supply conduit (14, 16) further comprises a source conduit (14) and an output conduit (16) adjoined to the source conduit (14) and wherein the juncture (20) is formed where the source conduit (14) adjoins the output conduit (16); and wherein said gradually reducing further comprises providing a tapered cylinder (12) having an inlet (22) with an inlet diameter and an outlet (24) having a smaller diameter than the inlet diameter, at least a portion of said tapered cylinder (12) being disposed within the juncture (20).

12. The method of claim 9, wherein the fluid-receiving apparatus (82) is a heating system.

13. The method of claim 9, further comprising controlling flow in the fluid- receiving apparatus (82) by operating at least one valve (83) operably disposed within the return conduit (84, 86).

14. The method of claim 9, further comprising: connecting the supply conduit (14, 16) to a heat-exchange conduit (62); and connecting the heat-exchange conduit (62) to the return conduit (84, 86).

15. The method of claim 11 , further comprising reducing fluid flow in the output conduit (16) to divert fluid from the juncture (20) into the bypass conduit (18).

16. The method of claim 11 , further comprising increasing fluid flow in the output conduit (16) to divert fluid from the bypass conduit (18) into the juncture (20).

17. The method of claim 11 , further comprising directing fluid from the source conduit (14) to the output conduit (16) by disposing the source conduit (14) and the output conduit (16) along a common axis and directing the tapered cylinder outlet (24) toward the output conduit (16).

18. The method of claim 9, wherein said restricting further comprises axially aligning the supply conduit (14) and the output conduit (16).

19. The method of claim 19, wherein said restricting further comprises aligning the bypass conduit (18) perpendicularly to the supply conduit (14) and the output conduit (16).

20. A method of controlling a fluid flow through a closed system (100) that includes a fluid-receiving apparatus (82) that has an output conduit (16) that fluidly communicates with a discharge port of a pump (44) through a supply conduit (14), the fluid-receiving apparatus (82) also fluidly communicating with a return conduit (84, 88) that fluidly communicates with an intake port of the pump (44), the system (100) further including a bypass conduit (18) extending from a juncture (20) between the output conduit (16) and the supply conduit (14) to the return conduit (84, 88) to facilitate fluid flow therebetween, said method comprising: pumping an output of fluid from the pump (44) into the supply conduit (14, 16); and directing said fluid output into the output conduit (16) at the juncture (20) to reduce the amount of fluid output flowing into the bypass conduit (18).

21. The method of claim 20, wherein said directing further comprises : axially aligning the supply conduit (14) and the output conduit (16); and providing a tapered cylinder (12) having an inlet (22) with an inlet diameter disposed at the source conduit (14) and an outlet (24) having a smaller diameter than the inlet diameter, said tapered cylinder outlet (24) projecting into the juncture (20) at least partially beyond the bypass conduit (18).

22. The method of claim 20, wherein the fluid-receiving apparatus (82) is a heating system.

23. The method of claim 20, further comprising connecting the bypass conduit (18) to a second fluid-receiving apparatus (66).

24. The method of claim 20, further comprising reducing fluid flow through the fluid-receiving apparatus (82) to increase fluid flow into the bypass conduit (18) by operating at least one valve (104) connected to the output conduit (16).

25. A closed system (40) comprising: a fluid-receiving apparatus (82); a supply conduit (14, 16) in fluid communication with said fluid- receiving apparatus (82); a pump (44) having a discharge port in fluid communication with the supply conduit (14, 16) and an intake port in fluid communication with a fluid storage tank (42), said pump (44) pumping an output of fluid from said storage tank (42) into said supply conduit (14, 16); a return conduit (84, 86, 88) in fluid communication with said fluid- receiving apparatus (82) and said storage tank (42); a bypass conduit (18) extending between the supply conduit (14, 16) and the return conduit (84, 86) to facilitate fluid flow therebetween; and a T-fitting connecting to said inlet conduit (14), said outlet conduit (16), and said bypass conduit (18) together to form and a juncture (20) therebetween; and a tapered cylinder (12) disposed within said juncture (20), said cylinder (12) having an inlet (22) having an inlet diameter and an outlet (24) having a smaller diameter than said inlet diameter.

26. The system (40) of claim 25, further comprising a valve (83) disposed in said return conduit (86) for controlling fluid flow through said fluid-receiving apparatus (82).

27. The system (40) of claim 25, further comprising a heat-exchange conduit (62) in fluid communication with said supply conduit (14) and said return conduit (84, 88) and a second fluid-receiving apparatus (66) in fluid communication with said heat-exchange conduit (62).

28. The system (40) of claim 27, further comprising a valve (64) disposed in said heat-exchange conduit (62) for controlling fluid flow through said second fluid-receiving apparatus (66).

29. A closed system (100) comprising: a fluid-receiving apparatus (82); a supply conduit (14, 16) in fluid communication with said fluid- receiving apparatus (82); a pump (44) having a discharge port in fluid communication with the supply conduit (14, 16) and an intake port, said pump (44) pumping an output of fluid into said supply conduit (14, 16); a return conduit (84, 88) in fluid communication with said fluid- receiving apparatus (82) and said intake port of said pump (44); a bypass conduit (18) extending between the supply conduit (14, 16) and the return conduit (84, 88) to facilitate fluid flow therebetween; a T-fitting connecting said inlet conduit (14), said outlet conduit (16), and said bypass conduit (18) together to form a juncture (20) intermediate said inlet conduit (14), said outlet conduit (16), and said bypass conduit (18); and a tapered cylinder (12) disposed within said juncture (20), said cylinder (12) having an inlet (22) having an inlet diameter and an outlet (24) wherein said tapered cylinder outlet (24) has a smaller diameter than the inlet diameter.

30. The system (100) of claim 29, further comprising a valve disposed in one of said outlet conduit (16), said return conduit (84), and said fluid-receiving apparatus (82).

31. The system (100) of claim 29, further comprising a second fluid-receiving apparatus (66) in fluid communication with said bypass conduit (18).