Patent GB-898899-A (GB)
Title: Improvements in and relating to installations and apparatus for washing, cleansing or extracting dust from gases
IPC: B01D45/12
Filed: 1958-06-23
Abstract: 898,899. Centrifugal separators. DE LA FOURNIERE, M. M. P. R. June 23, 1958 [June 21, 1957], No. 19972/58. Class 23. [Also in Group XII] An apparatus for removing entrained dust particles from gases comprises a set of two chambers each having a side a contour of which is substantially that of the logarithmic spiral, one of the two horizontal surfaces of each chamber being provided with a central orifice the centre of which is substantially the pole of the spiral, the chambers being in communication through these orifices and each being provided with a further orifice remote from the scroll axis, so that the gas stream entering one of the chambers through the remote orifice thereof will be shaped into a vortex the tangential speed of which decreases from the periphery to the axis with a corresponding pressure drop, which vortex will flow through the central orifices out of the chamber and into the other chamber, the apparatus also being provided with a duct whereby suitable treating liquid may be discharged through an orifice into the vortex. In one embodiment (see Figs. 1-3) gas to be cleaned enters chamber 11 through tangential pipe 17 and leaves through the aperture 12 in the form of a whirling stream, passing into apertured pipe 14 so that the dust particles are thrown by centrifugal force into the outer pipe 15 and are removed through 16. The gas stream then passes into spiral cavity 5 and travels in the direction shown by the arrows, dust particles passing through perforated wall 8 into pipe 9 while the stream of cleaned gas issues from pipe 6. Cleaning liquid is lead into chamber 1 and 11 by means of pipes 18 and 19 situated along the axis of the logarithmic spirals. In the embodiment shown the logarithmic walls of the chambers are of opposed hands, but if preferred the apparatus may be so constructed that these logarithmic walls are of the same hand. In the embodiment shown in Figs. 6 and 7, logarithmic chamber 11b is connected to logarithmic chamber 1b by the unperforated pipe 14b, the outlet pipe 6b of chamber 1b being unperforated, and connected to the inlet end of a cyclone 23 having at its upper part a central outlet pipe 24, so that liquid and dust collects in the bottom of the cyclone 23 and is evacuated by means of pipe 25 while cleansed gas leaves cyclone 23 through exit pipe 24. In a further embodiment illustrated in Figs. 8 and 9, the first logarithmic chamber 11c is connected by means of conical pipe 14c to the second logarithmic chamber 1c, in which is disposed a fan 31 driven by motor 33; dust particles pass through the perforated wall of logarithmic chamber 1c into pipe 9c while dust freed gas leaves the apparatus through exit pipe 6c. In the embodiment shown in Figs. 10 and 11, the apparatus of Figs. 1-3 is disposed within a casing 41 which is divided by partition 42 into two compartments. Dusty gas entering inlet pipe 17d entrains liquid through pipe 19d from a reservoir, the cleaned gas eventually leaving the tank through tangential pipe 43, while the liquid and dust particles are thrown by centrifugal force against the walls of the upper part of tank 41 and thence pass by means of pipe 44 to the reservoir in the lower part of the tank.