GB2183175A - Device for producing smoke or mist - Google Patents

Abstract

The device has generally a cylindrical metal block 1 containing a heater 2, the metal block 1 acting as a heat sink and being surrounded by an outer sleeve 3 defining with the block 1 a slim annular heating chamber 4 therebetween, the chamber 4 having a fluid inlet 5 and downstream thereof bores 6 leading into an annular expansion chamber 7 with a plurality of outlets 8 leading therefrom to the atmosphere. <IMAGE>

Description

SPECIFICATION Device for producing a smoke or mist effect This invention relates to a device for producing a smoke or mist effect.

Such devices are known particularly to produce theatrical effects. Hitherto, such devices have only been normally provided with a single smoke outlet and, if more than one outlet was desired, either a multi-block device, i.e. a device with two or more heater blocks in it was used, with the obvious disadvantage of duplication of parts, or conduits with junction pieces had to be attached to the device and the increased length of travel thereby produced lessened the smoke effect once it had reached its ultimate outlets. Alternatively, more than one device had to be provided to produce the desired effect.

According to the present invention, there is provided a device for producting a smoke or mist effect, the device including a generally cylindrical metal block containing heating means, the metal block acting as a heat sink and being surrounded by an outer sleeve defining with the block a slim cylindrical heating chamber therebetween, said chamber having a fluid inlet and downstream thereof bores leading into a substantially annular expansion chamber with a plurality of outlets leading therefrom to the atmosphere.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawing, in which the single Figure is a diagrammatic sectional view of a device for producing a smoke or mist effect according to the invention.

The drawing shows a generally cylindrical metal block 1 containing heating means which may be in the form of an electric heater 2, the block 1 acting as a heat sink. Closely surrounding the metal block 1 is a metal outer sleeve 3 which defines with the block 1 a slim cylindrical heating chamber 4 therebetween.

The heating chamber 4 has a fluid inlet 5 which leads through the block 1 about one third of the way down the block into the chamber 4, a tortuous path being provided to achieve optimum heating of the fluid.

At a downstream end of the heating chamber 4, bores 6 in the block 1 lead from the chamber 4 into a single, substantially annular expansion chamber 7. The expansion chamber 7 slants downwardly towards the end of the block 1 and from that chamber 7 a plurality of outlet bores 8 are provided. Threaded brass tubes 9 are screwed into the base of the block 1 to meet the bores 8, the tubes 9 constituting outlet nozzles protruding slightly from the end of the block 1. A heavy weld 10 is provided to secure the sleeve 3 and block 1 together, the weld being a heavy one ing order to withstand thermal shock.

In use, a fluid suitable for generating smoke or mist is forced under pressure into the inlet 5, for example by means of a small pump to produce the required pressure or by means of an aerosol canister, control of the entry of fluid being achieved by a fluid valve or a solenoid, and the fluid is forced down the heating chamber 4, which has been previously heated to the desired temperature (preferably about 260-280"C) by the heating means 2. The pressure for forcing the fluid into the chamber 4 can also be provided by using a pressurised "inert" gas such as CO2 or air.The narrow space forming the chamber 4 causes the fluid to build up to a high pressure which is then expelled through the bores 6 and into the expansion chamber 7, where the pressure and temperature lowers to produce the smoke or mist, which is then expelled via the multiple bores 8 from the nozzle tubes 9 into the atmosphere. The tubes 9 are as short as practicable in order that they may be kept hot to retain optimum smoke producing effect.

Preferably, four smoke outlets are provided, these being equally angularly spaced around the base of the cylindrical block so that, when the device is, for example, suspended from a ceiling, the smoke is expelled uniformly from the four nozzles in four different directions.

1. A device for producing a smoke or mist effect, the device including a generally cylindrical metal block containing heating means, the metal block acting as a heat sink and being surrounded by an outer sleeve defining with the block a slim cylindrical heating chamber therebetween, said chamber having a fluid inlet and downstream thereof bores leading into a substantially annular expansion chamber with a plurality of outlets leading therefrom to the atmosphere.

2. A device as claimed in claim 1 wherein the heating means is electrical and adapted to raise the temperature of the metal block to about 280"C.

3. A device as claimed in claim 1 or claim 2 wherein the fluid inlet is about one third of the way down the block toward the fluid outlets.

4. A device as claimed in any of the preceding claims wherein the outer sleeve is welded to the metal block.

5. A device as claimed in any one of the preceding claims wherein four fluid outlets are provided mutually at right angles.

6. A device as claimed in any one of the preceding claims wherein the expansion chamber is formed within the metal block.

7. A device as claimed in any one of the preceding claims wherein the fluid outlets are formed within the metal block.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (9)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Device for producing a smoke or mist effect This invention relates to a device for producing a smoke or mist effect. Such devices are known particularly to produce theatrical effects. Hitherto, such devices have only been normally provided with a single smoke outlet and, if more than one outlet was desired, either a multi-block device, i.e. a device with two or more heater blocks in it was used, with the obvious disadvantage of duplication of parts, or conduits with junction pieces had to be attached to the device and the increased length of travel thereby produced lessened the smoke effect once it had reached its ultimate outlets. Alternatively, more than one device had to be provided to produce the desired effect. According to the present invention, there is provided a device for producting a smoke or mist effect, the device including a generally cylindrical metal block containing heating means, the metal block acting as a heat sink and being surrounded by an outer sleeve defining with the block a slim cylindrical heating chamber therebetween, said chamber having a fluid inlet and downstream thereof bores leading into a substantially annular expansion chamber with a plurality of outlets leading therefrom to the atmosphere. For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawing, in which the single Figure is a diagrammatic sectional view of a device for producing a smoke or mist effect according to the invention. The drawing shows a generally cylindrical metal block 1 containing heating means which may be in the form of an electric heater 2, the block 1 acting as a heat sink. Closely surrounding the metal block 1 is a metal outer sleeve 3 which defines with the block 1 a slim cylindrical heating chamber 4 therebetween. The heating chamber 4 has a fluid inlet 5 which leads through the block 1 about one third of the way down the block into the chamber 4, a tortuous path being provided to achieve optimum heating of the fluid. At a downstream end of the heating chamber 4, bores 6 in the block 1 lead from the chamber 4 into a single, substantially annular expansion chamber 7. The expansion chamber 7 slants downwardly towards the end of the block 1 and from that chamber 7 a plurality of outlet bores 8 are provided. Threaded brass tubes 9 are screwed into the base of the block 1 to meet the bores 8, the tubes 9 constituting outlet nozzles protruding slightly from the end of the block 1. A heavy weld 10 is provided to secure the sleeve 3 and block 1 together, the weld being a heavy one ing order to withstand thermal shock. In use, a fluid suitable for generating smoke or mist is forced under pressure into the inlet 5, for example by means of a small pump to produce the required pressure or by means of an aerosol canister, control of the entry of fluid being achieved by a fluid valve or a solenoid, and the fluid is forced down the heating chamber 4, which has been previously heated to the desired temperature (preferably about 260-280"C) by the heating means 2. The pressure for forcing the fluid into the chamber 4 can also be provided by using a pressurised "inert" gas such as CO2 or air.The narrow space forming the chamber 4 causes the fluid to build up to a high pressure which is then expelled through the bores 6 and into the expansion chamber 7, where the pressure and temperature lowers to produce the smoke or mist, which is then expelled via the multiple bores 8 from the nozzle tubes 9 into the atmosphere. The tubes 9 are as short as practicable in order that they may be kept hot to retain optimum smoke producing effect. Preferably, four smoke outlets are provided, these being equally angularly spaced around the base of the cylindrical block so that, when the device is, for example, suspended from a ceiling, the smoke is expelled uniformly from the four nozzles in four different directions. CLAIMS

1. A device for producing a smoke or mist effect, the device including a generally cylindrical metal block containing heating means, the metal block acting as a heat sink and being surrounded by an outer sleeve defining with the block a slim cylindrical heating chamber therebetween, said chamber having a fluid inlet and downstream thereof bores leading into a substantially annular expansion chamber with a plurality of outlets leading therefrom to the atmosphere.

2. A device as claimed in claim 1 wherein the heating means is electrical and adapted to raise the temperature of the metal block to about 280"C.

3. A device as claimed in claim 1 or claim 2 wherein the fluid inlet is about one third of the way down the block toward the fluid outlets.

4. A device as claimed in any of the preceding claims wherein the outer sleeve is welded to the metal block.

5. A device as claimed in any one of the preceding claims wherein four fluid outlets are provided mutually at right angles.

6. A device as claimed in any one of the preceding claims wherein the expansion chamber is formed within the metal block.

7. A device as claimed in any one of the preceding claims wherein the fluid outlets are formed within the metal block.

8. A device as claimed in any one of the preceding claims when adapted to be suspended from a ceiling with the fluid outlets positioning obliquely downwardly.

9. A device as claimed in claim 1 substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.