GB2227285A

GB2227285A - Fluid flow accelerator

Info

Publication number: GB2227285A
Application number: GB8828053A
Authority: GB
Inventors: Anthony William Ward
Original assignee: WARDTEC Ltd
Current assignee: WARDTEC Ltd
Priority date: 1988-12-01
Filing date: 1988-12-01
Publication date: 1990-07-25
Anticipated expiration: 2008-12-01
Also published as: GB8828053D0; GB2227285B

Abstract

An accelerator device 22 for use in a fluid flow system has a first inlet 29, second inlet 30 and an outlet 25, the second inlet and the outlet being disposed perpendicular to one another and the first inlet extending parallel with the outlet and affording a constriction 35 such that fluid flow downstream of the first inlet is accelerated relative to the rate of fluid flow upstream of the first inlet. The constriction 35 is bounded by diverging portions on either side. <IMAGE>

Description

Title: "Accelerator devised in or for a fluid flow system" Description of Invention This invention relates to an accelerator device in or for a fluid flow system and particularly, but not exclusively, a central heating system of the kind, hereinafter referred to as the kind specified, comprising a circuit including a heater and a first heat exchanger through which water is circulated by a pump and there being a second heat exchanger connected in parallel with the first heat exchanger. Usually the heat exchanger is a boiler which can be fired by gas, or solid fuel, or any other suitable fuel, the first heat exchanger comprises at least one radiator and the second heot exchanger comprises a cylinder for storing water heated by the circulating hot water of the circuit and is disposed at a level above the level of the heater.The pump is preferably disposed in a return conduit from the first heat exchanger to the heater and an inlet of the second heat exchanger may be connected to a supply conduit from the heater to the first heat exchanger whilst an outlet of the second heat exchanger is connected to the return conduit between the pump and the heater.

An object of the invention is to provide a new or improved accelerator device in for a fluid flow system.

According to one aspect of the present invention we provide an accelerator device in or for a fluid flow system, the accelerator comprising a body having first and second inlets and an outlet, the first inlet being connected in communication with an accelerator nozzle disposed so as to accelerate the flow of liquid from the second inlet through the device wherein the accelerator nozzle comprises a reduced cross-section neck portion bounded by diverging portions on each of the upstream and downstream sides of the smallest cross-section part of the neck portion.

The diverging portion on said downstream side may be curvilinear in longitudinal cross-section and may be generally bell-mouthed.

The nozzle may have a rectilinear longitudinal axis which may be eccentrically disposed relative to a rectilinear longitudinal axis of the outlet.

The second inlet may be orthogonally disposed relative to said longitudinal axes.

The accelerator device may be made by performing a forming operation to provide a body having the outlet, the second inlet and an opening, and securing a tube in the opening, for example by soldering or brazing, to project into the body, the tube providing the first inlet and the accelerator nozzle.

At least one of the first inlet, second inlet and the outlet may be provided with a circumferentially extending inwardly opening groove in which a solder or like composition is disposed.

According to a second aspect of the present invention we provide an accelerator device in or for a fluid flow system, the accelerator comprising a body having first and second inlets and a outlet, the first inlet being connected in communication with an accelerator nozzle disposed so as to accelerate the flow of liquid from the second inlet through the device wherein at least one of the first inlet, second inlet and the outlet is provided with a circumferentially extending inwardly opening groove in which a solder or like composition is disposed.

The area of the smallest cross-section of the injector nozzle may be less than the area of the outlet or the second inlet.

The invention will now be described by way of example with reference to the accompanying drawings wherein: FIGURE I is a diagrammatic view of a central heating system embodying the present invention, FIGURE 2 is a cross-sectional view, to an enlarged scale, through an injection device of Figure I, and FIGURE 3 is a cross-sectional view showing a modification of the injection device of Figure 2.

Referring to Figures I and 2 of the drawings, a central heating system comprises a circuit 10 comprising a boiler II connected by a supply conduit 12 to a radiator 13 which is connected by a return conduit 14 to the boiler I I.

Disposed in the return conduit 14 between the radiator 13 and the boiler I I is a circulating pump 15. An indirect cylinder ló having an internal coil 17 is connected to the supply conduit 12 by a secondary supply conduit 18 and to the return conduit 14 by a secondary return conduit 19, which is connected to the return conduit 14 downstream of the pump 15. The indirect cylinder I 6 is provided, in conventional manner, with cold water from a tank 20 and is provided with an outlet conduit 21 which provides water, at a desired location, heated as a result of flow of hot water from the boiler 11 through the coil 17.

If desired, the circuit may include more than one radiator 13 and the boiler II may be fired in any desired manner, for example it may be gasfired, oil-fired, or solid fuel-fired. Alternatively, instead of a boiler II the circuit may include another form of heater, such as an electrical heater.

The secondary conduit 19 is connected to the return conduit 14 by means of an accelerator device 22 which is shown in cross-section in Figure 2.

The accelerator device 22 comprises a body, made of copper and comprising two perpendicularly disposed and intersecting cylindrical parts 24a, 24b. The cylindrical part 24a provides an outlet 25 whilst the cylindrical part 24b has an opening 26 therein in which is secured, by brazing, a tube 27 which provides an accelerator nozzle 28 and a first inlet 29. The longitudinal axis X-X of the tube 29 is rectilinear and is disposed eccentrically relative to the central longitudinal rectilinear axis Y-Y of the part 24.

The cylindrical part 24b of the body provides at one end a second inlet 30 and at its other end has a threaded boss 31 brazed therein to which a drain plug or blanking cap may be connected. The body parts 24a, 24b and the tube 27 adjacent to the free ends thereof are provided with a circumferentiolly extending inwardly open groove 32, 33, 38 respectively which is filled with solder S in conventional manner. Preferably the solder is a lead free solder.

The tube 27 is of cylindrical configuration externally of the body 23 whilst internally of the body 23 it provides a reduced cross-sectional area neck portion 34 having a smallest cross-sectional area portion 35 bounded on the downstream side thereof by a bell-mouthed diverging part 36 and on the upstream side by a diverging frusto-conical part 37. The area of the smallest cross-sectional part 35 is less than the cross-sectional area of the second inlet 30 and outlet 25.

The device is made in conventional manner by performing a pressure forming operation on a suitable blank of copper, or other suitable metal, and securing the tube 27 and boss 31 in position by brazing. If desired, however, the tube 27 may be secured in any other suitable way. The forming operation also forms the circumferentially extending recesses 32 which are then filled with solder in conventional manner.

In use, water flowing downwardly through the secondary return conduit 19 from the cylinder 16 enters the accelerator device 22 via the second inlet 30 and flows therefrom through the outlet 25 and thence to the boiler II.

However, when the pump 15 is operating the accelerator nozzle 28 has a venturi effect which increases the speed of the water in the return line 14 on the downstream side of the accelerator device 22 compared with the speed on the upstream side thereof and in addition entrains the water entering the accelerator nozzle from the cylinder 16 via the second inlet 30 and increases the velocity of this liquid also.

By providing the nozzle with a diverging part of curvilinear configuration in cross-section downstream of the smallest cross-sectional part 35, an improved acceleration is achieved with the avoidance of turbulence.

Although in this example the tube 27 has been described as being eccentrically disposed relative to the axis Y-Y, if desired it may be disposed so that the longitudinal axes X-X and Y-Y coincide.

By providing the grooves 32, 33, 38 filled with solder, connection of the device in a central heating circuit is facilitated, since it is simply necessary for a plumber to heat the device in the region of the grooves 32, 33, 38 to cause the solder to melt and form a liquid tight joint to the relevant conduits of the circuit.

If desired the accelerator device may be used in any desired fluid flow system where acceleration and entrainment of fluid is required.

Figure 3 shows an alternative configuration and the same reference numerals have been used as were used in connection with Figure 2 to refer to corresponding parts.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, or a class or group of substances or compositions, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAIMS:

An An accelerator device in or for a fluid flow system, the accelerator comprising a body having first and second inlets and an outlet, the first inlet being connected in communication with an accelerator nozzle disposed so as to accelerate the flow of liquid from the second inlet through the device, wherein the accelerator nozzle comprises a reduced cross-section neck portion bounded by diverging portions on each of the upstream and downstream sides of the smallest cross-section part of the neck portion.
2. An accelerator device according to claim I in which the diverging portion on the downstream side is curvilinear in longitudinal crosssection.
3. An accelerator device according to claim I or claim 2 in which the diverging portion on said downstream side is generally bell-mouthed.
4. An accelerator device according to any one of the preceding claims in which the nozzle has a rectilinear longitudinal axis which is eccentrically disposed relative to a rectilinear longitudinal axis of the outlet.
5. An accelerator device according to claim 4 in which the second inlet is orthogonally disposed relative to said longitudinal axes.
6. An accelerator device according to any one of the preceding claims which is made by performing a forming operation to provide a body having the outlet, the second inlet and an opening, and securing a tube in the opening to project into the body, the tube providing the first inlet and the accelerator nozzle.
7. An accelerator device according to any one of the preceding claims in which at least one of the first inlet, and the outlet are provided with a circumferentially extending inwardly opening groove in which a solder or like composition is disposed.
8. An accelerator device in or for a fluid flow system, the accelerator comprising a body having first and second inlets and a outlet, the first inlet being connected in communication with an accelerator nozzle disposed so as to accelerate flow of liquid from the second inlet through the device wherein at least one of the first inlet, second inlet and the outlet is provided with a circumferentially extending inwardly opening groove in which a solder or like composition is disposed.
9. ' An accelerator device according to any one of claims I to 8 in which the area of the smallest cross-section of the accelerator nozzle is less than the area of the outlet or the second inlet.
10. An accelerator device substantially as described hereinbefore with reference to the accompaning drawings.

II. Any novel feature or combination of features disclosed herein.