For a better understanding of the invention and to show how the same may be carried into effect reference is now made by way of example to the accompanying drawings in which:
Fitted over the impeller 4 is a housing 5, which is mounted to the driving motor 1 by a rear plate 11, through which the drive shaft 2 extends. The housing 5 is circular in cross-section (in a plane orthogonal to the rotational axis of the impeller 4) and is positioned concentrically with the impeller 4 and the drive shaft 2. A mechanical seal 3 is disposed between the rear plate 11 and the drive shaft 2, to isolate the housing 5 from vibrations of the motor 1, drive shaft 2 and impeller 4. The housing 5 defines an intake port 12 and an outlet port 13, and passages connecting the ports 12, 13 with the impeller 4. The intake port 12 and the outlet port 13 lie substantially in the same plane. In this example, the intake port 12 is positioned concentrically within the outlet port 13, the outlet port 13 surrounding the inlet port 12 and being annular in shape.
The housing 5 includes a central tube 7 of circular cross-section that extends along the longitudinal axis defined by the drive shaft 2, from the intake port 12 to an entrance region of the impeller. The tube defines an intake passage, along which air is drawn from the intake port 12 to the impeller 4. Thus, the intake passage directs air form the intake port 12 to the impeller 4.
The housing 5 also comprises a tubular outer wall 14 and a tubular inner wall 15, each arranged coaxially with the central tube. The outer wall 14 surrounds the inner wall 15, which in turn surrounds the central tube 7. The outer wall 14 and the inner wall 15 are spaced apart from one another, the space therebetween defining an outlet passage 6 which extends from a discharge region of the impeller 4 to the outlet port 13. Air leaving the impeller 4 is thereby directed from the impeller 4 to the outlet port 13. The outlet passage 6 is shaped such that its first end adjacent to the impeller 4 is positioned around the outside perimeter of the impeller blades, and its second end, which defines the outlet port 13, surrounds the central tube 7. In this example, the impeller 4 has a greater diameter than the central tube 7, so to achieve the described configuration of the outlet passage, the inner wall 15 and the outer wall 14 have a decreasing outer diameter as they extend from the impeller 4 to the outlet port 13. In other examples, however, the walls may have a substantially constant or even an increasing diameter.
The central tube 7 is held in place within the inner wall 15 by plates 16 that extend between the two parts.
The front end of the blower 20, being in the plane containing the intake port 12 and the outlet port 13, is provided with an annular connection flange 8 that surrounds the outlet port 13. The flange 8 allows the blower 20 to be connected to a textiles processing machine, for example by bolts or rivets extending through holes in the flange 8 and fastened to a wall of the machine, or to an end of a pipe that leads into the machine.
Each of the circular passages 10 has a cross-sectional flow area (the area through which air can flow from the impeller 4) that increases along the length of the passage 10. As can be seen in
The cross-sectional flow area of the spiral passages 9 similarly increases along the length of the spiral passages 9 from the circular passages 10 to the outlet port 13.
To operate the blower, the motor 1 is activated to rotate the impeller 4. Rotation of the impeller produces a pressure differential between its entrance region and its discharge region, and hence between the intake port 12 and the outlet port 13 which are respectively in communication with those regions by virtue of the inlet passage 7 and the outlet passage 6. The pressure differential, and negative pressure at the entrance region of the impeller 4 causes air to be drawn in through the intake port 12 and to travel along the central tube 7 to the impeller 4. The rotation of the impeller 4 imparts centrifugal force to the air, which passes across the impeller 4, and is forced into the outlet passage 6. The air then travels to the outlet port 13 by way of the circular passages 10 and the spiral passages 9; upon reaching the outlet port 13 it is discharged as a jet or air. The described arrangement of the inlet port 12 and the outlet port 13 are such that the air is drawn in and subsequently discharged along directions which are opposite but substantially parallel. The direction of air flow from intake to discharge is shown by arrows in
The increase in the flow area along the lengths of the circular paths 10 and the spiral paths 9 slows down the speed of air flow inside the paths, converting part of the kinetic energy of the propagating air to an increase in pressure, in accordance with Bernoulli's law. This pressure increase allows the air to be discharged as a jet, suitable to be directed into a textile machine for the loosening of fabric being dyed therein.
The housing can be made from any material suitable for use in the environment of a textiles processing machine and which can be formed into the desired shape, such as a metal, including steel, stainless steel or aluminum, or a moulded plastics material.
The blower of the present invention is not limited to the example shown in
Although the use of a separate blower for every tube is of particular benefit, blowers as described herein may also be associated with more than one tube in a machine, including the use of a manifold, if desired. The smaller size of such blowers as compared to known blowers still offers advantages.
Although the described blowers are particularly suited for use with textiles processing machines, particularly dyeing machines, the invention is not so limited. The blowers may be used for other applications in which the described arrangement of taking in and discharging air along parallel but opposite directions is found to be beneficial.
Number | Date | Country | Kind |
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06255093.4 | Oct 2006 | EP | regional |