GB670752A - Improved separator for separating solid particles from gases - Google Patents

Abstract

670,752. Centrifugal separators. AKTIEBOLAGET LINDEROTHS PATENTER, and BLOMEN, T. July 18, 1950 [Sept. 14, 1949], No. 23730/49. Class 23 A gas cleaner comprises a conical duct 1, Fig. 2, having louvred openings 2 at an acute angle to the generant of the duct and mounted in a conical casing 10 which forms with the duct 1 a dust-laden gas inlet passage 11 connected to the inlet 7 of the casing 10 and of annular form decreasing in crosssection towards the apex where it provides an outlet 14 for a minor portion of the gas containing the whole of the dust; the base of the passage 1 having guide means, e.g. angled blades 9<1> for imparting spiral motion to the incoming dust-laden gas. The dust-saturated gas portion traverses a cyclone separator 17 and cleaned gas is returned by a fan 13 to the inlet 7. The spiral motion of the incoming gas serves to maintain at a low level the concentration of dust adjacent the openings 2 near the apex of the duct 1 and so reduces the braking effect normally caused by the dust. Uniform distribution of gas traversing the openings 2 is assisted by decreasing the angularity of inwardly directed tongues 18, Fig. 9, as the apex is approached and by the introduction of a frusto-conical baffle 19 within the duct 1. The most favourable separation effect is obtained when the gas current retains its spiral motion upon passing through the openings 2 and to this end the tongues 18 are curved and the angle between the trailing edges of the tongues and the surface of the duct are such that the gas current emanating from an anterior tongue forms a tangent with the posterior tongue. For further assisting the spiral motion of the gas within the duct 1 the openings 2, which are 'elongated, are so arranged that the angle B, Fig. 12 between a tangent a-a of the duct 1 normal to the major axis of the slots and a plane o-o normal to the axis of the duct 1 is smaller than the angle alpha<1> between the gas current directed against the surface of the duct 1 and the said transverse plane; the value of alpha<1>-# decreasing towards the apex of the duct 1. An alternative means of securing uniform distribution of gas through the openings 2 comprises making the ratio of the diameters of the apex and base of the duct 1 equal to the ratio at the base of the rotating component of the gas velocity and its component parallel to the generant. In a modification spiral motion may be effected by disposing the inlet 7 tangentially to the base of the duct 1, and the cyclone 17 is connected directly to the apex of the duct 1 and the cleaned air is returned to the inlet along through a duct located along the axis of the apparatus.