Patent GB-992386-A (GB)
Title: Method for separating particles of dust or liquid from gases and cyclone collector orprecipitator for carrying out the method
IPC: B01D45/12
Filed: 1964-04-27
Abstract: 992,386. Cyclone separators; electrostatic precipitators. SCHUCHTERMANN & KREMER-BAUM A.G. FUR AUFBEREITUNG. April 27, 1964 [May 14, 1963 ; Feb.14, 1964], No. 17428/64. Headings B2J and B2P. [Also in Division G3] In a cyclone for separating dust or liquid particles from a gas, Fig. 1, at least two axially spaced inlet ducts 4, 5 open out tangentially and in the same tangential direction into the cyclone turbulence chamber 1, the duct 4, which is adjacent the particle-collecting chamber 2 at one end of the turbulence chamber, feeding particle-laden gas to the turbulence chamber and the duct 5, which is adjacent a purified gas central outlet 3 at the other end of the turbulence chamber, feeding to the turbulence chamber an auxiliary gas current for the purpose of accelerating the rotation of purified gas currents so that any fine particles entrained therein are separated before discharge through the outlet 3. The auxiliary gas may be pure or particle-laden gas. A plurality of inlet ducts may be distributed at regular intervals over the periphery of the turbulence chamber at the levels of ducts 4, 5. In the dust separator shown, the kinetic energies of the dust-laden and auxiliary gas currents may be adjusted to each other in such a manner that the auxiliary gas current predominates and thus displaces into the dust-collecting chamber 2 the total current which carries with it the separated dust. Alternatively, the kinetic energies are adjusted in such a manner that in the space between the ducts 4 and 5 in the chamber 1, a neutral zone x is formed in which the axial components of motion of the two gas currents balance each other out so that the dust ejected by centrifugal action accumulates to form a rotating dust ring a from which, when saturation is reached, dust drops into the collecting chamber 2 as more dust is fed with the dust-laden gas. In order to maintain the neutral zone x between the ducts 4 and 5, the pressure ratio of the dustladen and auxiliary gas currents in the ducts is kept constant by an automatic control device shown in Fig. 2. Throttling members 14, 15 provided in the ducts 4, 5 are operated by a piston 16 controlled by pressure calibrators 17, 18 responsive to the pressures in the ducts 4, 5. The diaphragms of the calibrators engage the free ends of a balance beam 23 in opposition to springs 21, 22 which are adjustably tensioned to give the desired pressure ratio in the ducts. Baffle plates 24, 25 secured to the beam 23 control the discharge from nozzles 26, 27, of fluid supplied by a conduit 29 to the working spaces in the cylinder 28 on both sides of the piston 16. In operation, should, for example, the pressure in the duct 5 increase, the balance beam 23 rotates, from its neutral position shown, in a clockwise direction causing the baffle plate 24 to move closer to the nozzle 26 whereupon pressure increases in the left-hand working space of the cylinder and the piston 16 is displaced to the right with the result that the duct 5 is throttled to an increased extent by the member 15 with simultaneous reduced throttling action of the member 14 in the duct 4. As soon as the pressure ratio beyond the throttling members 14, 15 is restored, the balance beam 23 resumes its neutral position with the piston remaining in its new position. The separation of the dust may be improved by providing: (a) a rod-shaped discharge electrode 6 in the turbulence chamber the wall of which is earthed at 8 so as to function as a collecting electrode; (b) nozzles 9, 10 for spraying water into the rotating dust ring a and/or into the dust-laden gas current.