GB1595889A

GB1595889A - Dust extractor fan

Info

Publication number: GB1595889A
Application number: GB1828378A
Authority: GB
Original assignee: Charbonnages de France CDF
Current assignee: Charbonnages de France CDF
Priority date: 1977-05-13
Filing date: 1978-05-08
Publication date: 1981-08-19
Also published as: DE2820234A1; FR2390194A1; FR2390194B1; BE866766A

Description

(54) A DUST EXTRACTOR FAN (71) We, CHARBONNAGES DE FRANCE, a Public Institute organised and existing under the laws of France, of 9 Avenue Percier, 75008 Paris, (Seine) France, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a dust extractor fan.

U.S. Patent Specification No. 2,342,469 describes a device which is composed of a bowl in which a porous disc rotates, water being sprayed along the axis of the disc.

This device, which is intended for the airconditioning of a room, is not suitable for dust extraction, particularly when substantial extraction of dust requiring a large flow of water is involved.

It is an object of the invention to provide a fan which can withstand large flows of atomised water for the purpose of depositing large amounts of dust or other particles, such as may be encountered in mines, underground excavations, or industrial works.

According to the present invention there is provided a dust extractor fan comprising a substantially cylindrical casing having a suction opening, liquid atomisation means supported near said suction opening, a rotor disposed coaxially of said casing, and a substantially annular collector for the liquid on the inner wall of said casing coaxially thereof and aligned with said rotor, wherein a plurality of helicoidal ribs are provided on the inner wall of said casing on at least one side of the collector, said ribs being directed obliquely towards the collector in the direction of the rotation of the rotor.

In an embodiment the inner wall of the casing has, on each side of the collector, a plurality of ribs directed obliquely towards the collector in the direction of rotation of the rotor, and each part of the wall of the casing which is provided with helicoidal ribs is frustoconical and divergent in the direction of the collector.

Preferably, the collector is in the form of a spiral or a volute.

The dust extractor fan may also be provided with horizontal installation means for the casing.

The characteristics of the invention can be applied to dust extractor fans in which the rotor is a porous mass, whether they are of the suction type having an air delivery opening on the opposite side of the rotor to the suction opening, or whether they are of the mixing air-conditioning type in which the casing is in the form of a bowl whose opening serves sumultaneously for suction and for air delivery.

Embodiments of the present invention will hereinafter be described, by way of example, with reference to the accompanying drawings, in which: FIGURE 1 shows diagrammatically an axial section of a dust extractor fan of one embodiment of the invention, FIGURE 2 shows a perspective view of a part of a nozzle wall on each side of a collector of the fan of Figure 1, and FIGURE 3 shows diagramraatically an axial section of a fan of a further embodiment of the invention.

The apparatus shown in Figures 1 and 2 is a dust extractor fan of the suction type in which the suction aperture is on the left in the drawing and the air delivery opening is on the right. The fan has a cylindrical casing 1 in the general form of a nozzle formed by rigidly joining together three coaxially aligned sleeves 2, 3 and 4, each sleeve being open at both ends. The sleeve 2 has a suction opening 5 and supports at the centre of the opening 5 a water atomiser 6 connected to a water supply pipe 7. The sleeve 3 contains a thick coaxial rotor 8 composed of a cylindrical mass of open-pore foam mounted on a plate 9 by means of a screw 10 and a stop washer 11. The plate 9 is rotated by a shaft 12 driven by a motor 13 fixed in the sleeve 4 by means of three fastening brackets 14. All the rotating parts are centred on the axis of the nozzle 1. The sleeve 4 has an air delivery opening 15 at the opposite end to the suction opening 5.

The dust extractor fan shown in Figure 1 can be used for blowing air free from dust into a gallery either directly or through a ventilation shaft.

The sleeve 3 contains a collector 16 which is in the form of a spiral or a volute and which extends peripherally in the direction of rotation of the rotor 8 as far as an outlet pipe 17, as can be seen in Figure 2 which shows the sleeve 3 separately.

As is known per se, the inside face of the spiral collector 16 is set back in relation to the inner surface of the sleeve 3. On each side of the spiral 16 the sleeve 3 is provided with a number of regularly spaced helicoidal ribs directed towards the collector in the direction of rotation of the rotor, that is to say in the clockwise direction in Figure 2 and as viewed from the right in Figure 1 (arrow f). The space between any two ribs 18 serves as a guide passage for water thrown off by centrifugal force from the rotor against the inside wall of the nozzle.

In this way the water, which may be charged with dust, is directed more quickly towards the collector 16 so that for an equal instantaneous flow the spiral collector may be of smaller dimensions.

The sleeve 3 has the shape of two truncated cones 19, 20, which may or may not be symmetrical and whose larger bases are turned towards the spiral collector 16. The centrifugal force of the water which forms a vortex on the inner walls of the sleeve is thus fully utilised for accelerating the collection of water by the spiral collector 16.

Finally, the apparatus has a horizontal suspension ring 21.

The porous mass 8 acts as a suction means for dust-laden air.

At the same time a certain amount of water is introduced into it in the form of fine droplets. The mixture of air and water passes through the porous mass and is violently thrown against the walls of the nozzle with a radial movement because of the centrifugal force and a tangential movement because of the driving torque. Dust or other particles are either retained in the porous mass or entrained by the water thrown off against the walls and discharged through the spiral. The liquid thrown off in this manner is entrained by the ribs disposed regularly on the inner surface of the nozzle towards the spiral collector. Air completely free of dust is then blown though the opening 15.

Figure 3 shows a further embodiment in which, as is known per se, the opening 5 serves at the same time for suction through the centre and for delivering air in the form of an annular curtain on the periphery. This apparatus is a dust extractor fan acting through the stirring of air. It comprising a sleeve 22 very similar to the sleeve 2, a sleeve 23 of which the part at the opposite end of the sleeve 22 is a closed end 25 at the centre of which the shaft 12 driving the rotor 8 passes through its plate 9. The sleeve 23 surrounding the rotor is provided with a spiral collector 16 which is in contact with the end 25 and discharges into a pipe 17. The sleeve 23 is however frustoconical with its large base starting from the end 25 and has only one set of helicoidal ribs 18 directed towards the spiral obliquely in the direction of rotation of the rotor.

The sleeve 25 is a simple casing containing the motor 13.

The sleeve 3 has been shown separately as part of the apparatus of Figure 1. It could obviously be mounted on the apparatus shown in Figure 3, while similarly the sleeve 23 could be mounted on the apparatus shown in Figure 1.

The spiral collector 16 could have any suitable variation of section, and may or may not widen from its starting point near the pipe 17 to its outlet leading to the latter.

Having regard to the provisions of Section 9 of the Patents Act 1949, attention is directed to the claims of British Patent No.

1,501,473.

WHAT WE CLAIM IS:- 1. A dust extractor fan comprising a substantially cylindrical casing having a suction opening, liquid atomisation means supported near said suction opening, a rotor disposed coaxially of said casing, and a substantially annular collector for the liquid on the inner wall of said casing coaxially thereof and aligned with said rotor, wherein a plurality of helicoidal ribs are provided on the inner wall of said casing on at least one side of the collector, said ribs being directed obliquely towards the collector in the direction of the rotation of the rotor.

2. A dust extractor fan as claimed in Claim 1, wherein a plurality of helicoidal ribs are provided on the inner wall of said casing on each side of the collector, said ribs being directed obliquely towards the collector in the direction of rotation of the rotor.

3. A dust extractor fan as claimed in Claim 1 or 2, wherein each part of the wall of the casing which is provided with helicoidal ribs is frustoconical and divergent in the direction of the collector.

4. A dust extractor fan as claimed in any preceding Claim, wherein the collector is in the form of a spiral or a volute.

5. A dust extractor fan as claimed in any preceding Claim, further comprising means for mounting the casing so that the longitudinal axis thereof extends substantially horizontally.

6. A dust extractor fan as claimed in any

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. the opposite end to the suction opening 5. The dust extractor fan shown in Figure 1 can be used for blowing air free from dust into a gallery either directly or through a ventilation shaft. The sleeve 3 contains a collector 16 which is in the form of a spiral or a volute and which extends peripherally in the direction of rotation of the rotor 8 as far as an outlet pipe 17, as can be seen in Figure 2 which shows the sleeve 3 separately. As is known per se, the inside face of the spiral collector 16 is set back in relation to the inner surface of the sleeve 3. On each side of the spiral 16 the sleeve 3 is provided with a number of regularly spaced helicoidal ribs directed towards the collector in the direction of rotation of the rotor, that is to say in the clockwise direction in Figure 2 and as viewed from the right in Figure 1 (arrow f). The space between any two ribs 18 serves as a guide passage for water thrown off by centrifugal force from the rotor against the inside wall of the nozzle. In this way the water, which may be charged with dust, is directed more quickly towards the collector 16 so that for an equal instantaneous flow the spiral collector may be of smaller dimensions. The sleeve 3 has the shape of two truncated cones 19, 20, which may or may not be symmetrical and whose larger bases are turned towards the spiral collector 16. The centrifugal force of the water which forms a vortex on the inner walls of the sleeve is thus fully utilised for accelerating the collection of water by the spiral collector 16. Finally, the apparatus has a horizontal suspension ring 21. The porous mass 8 acts as a suction means for dust-laden air. At the same time a certain amount of water is introduced into it in the form of fine droplets. The mixture of air and water passes through the porous mass and is violently thrown against the walls of the nozzle with a radial movement because of the centrifugal force and a tangential movement because of the driving torque. Dust or other particles are either retained in the porous mass or entrained by the water thrown off against the walls and discharged through the spiral. The liquid thrown off in this manner is entrained by the ribs disposed regularly on the inner surface of the nozzle towards the spiral collector. Air completely free of dust is then blown though the opening 15. Figure 3 shows a further embodiment in which, as is known per se, the opening 5 serves at the same time for suction through the centre and for delivering air in the form of an annular curtain on the periphery. This apparatus is a dust extractor fan acting through the stirring of air. It comprising a sleeve 22 very similar to the sleeve 2, a sleeve 23 of which the part at the opposite end of the sleeve 22 is a closed end 25 at the centre of which the shaft 12 driving the rotor 8 passes through its plate 9. The sleeve 23 surrounding the rotor is provided with a spiral collector 16 which is in contact with the end 25 and discharges into a pipe 17. The sleeve 23 is however frustoconical with its large base starting from the end 25 and has only one set of helicoidal ribs 18 directed towards the spiral obliquely in the direction of rotation of the rotor. The sleeve 25 is a simple casing containing the motor 13. The sleeve 3 has been shown separately as part of the apparatus of Figure 1. It could obviously be mounted on the apparatus shown in Figure 3, while similarly the sleeve 23 could be mounted on the apparatus shown in Figure 1. The spiral collector 16 could have any suitable variation of section, and may or may not widen from its starting point near the pipe 17 to its outlet leading to the latter. Having regard to the provisions of Section 9 of the Patents Act 1949, attention is directed to the claims of British Patent No. 1,501,473. WHAT WE CLAIM IS:-

1. A dust extractor fan comprising a substantially cylindrical casing having a suction opening, liquid atomisation means supported near said suction opening, a rotor disposed coaxially of said casing, and a substantially annular collector for the liquid on the inner wall of said casing coaxially thereof and aligned with said rotor, wherein a plurality of helicoidal ribs are provided on the inner wall of said casing on at least one side of the collector, said ribs being directed obliquely towards the collector in the direction of the rotation of the rotor.

6. A dust extractor fan as claimed in any

preceding Claims, wherein said rotor is composed of a substantially cylindrical porous mass.

7. A dust extractor fan as claimed in any preceding Claim, further comprising an air delivery opening on the opposite side of the rotor to the suction opening.

8. A dust extractor fan as claimed in any of Claims 1 to 6, wherein said suction opening is also arranged to act as an air delivery opening.

9. A dust extractor fan substantially as hereinbefore described with reference to and as illustrated in Figures 1 and 2 of the accompanying drawings.

10. A dust extractor fan substantially as hereinbefore described with reference to and as illustrated in Figure 3 of the accompanying drawings.