Patent GB-386132-A (GB)
Title: Improvements in or relating to apparatus for straining liquids or gases
IPC: B01D35/12
Filed: 1932-01-27
Abstract: 386,132. Filters. VICKERS - ARMSTRONGS, Ltd., Vickers House, Broadway, Westminster, and WARDLE, J., 44, Hawcoat Lane, Barrow-in-Furness. Jan. 27, 1932, No. 2490. [Class 46.] In apparatus for straining liquids or gases a chamber within or surrounding a cylindrical strainer is divided into sections by one or more partitions or vanes and means are provided for effecting relative movement between one or more of the partitions and the surface of the chamber so as to reduce the capacity of one or more of the sections and cause a reverse cleansing flow without reducing the normal flow through the other sections. As shown in Figs. 1 and 2, the space within a cylindrical strainer A is divided into sections Bl .. B<4> by blades b<1>, carried in slots in vanes b on a spindle b<x> eccentric to the strainer and pressed outwardly by springs b<3>. The normal flow of fluid is from an inlet E<4> inward into the strainer A and out of the sections B<2>, B<4>, to an outlet E<1> through apertures b<2>, b<4> in a plug b<5>, fixed to the spindle b<x>. On rotation of the spindle b<x> by means of a handle c<2> the capacity of certain of the sections is reduced and there is a reverse flow through the corresponding parts of the strainer. The strainer itself may be rotated by means of a pinion A<4> gearing with peripheral teeth on the strainer. A scraper D engages the outer surface of the strainer. A modification is described in which the strainer is rotated about a fixed spindle b<x>. Fig. 15 shows a form intended for use as a petrol filter. The spindle C turns in a headplate which is formed with inlet E<4> and outlet El. In apparatus shown in Figs. 7 and 8, a strainer A is mounted on a spindle C so that it can be turned eccentrically to the outer casing. The normal flow is outwards through the strainer. The space outside the strainer is divided into sections by blades bl which are yieldingly mounted in slots in the outer casing. As shown in Figs. 9 and 11, a piston b moves in a cylinder F inside the strainer A, the space between the cylinder and strainer being divided into sections B<1>, B<2> by partitions b<9>. The interior of the cylinder communicates with the sections B<1>, B<2> through slots F, Fl respectively. When the strainer and cylinder F are turned by the spindle C, the piston is caused by pegs H<1> engaging inclined slots in the cylinder to move longitudinally. With the parts in the position shown the normal flow of fluid takes place through the section B<2>, the fluid passing away through an aperture A<12> to the outlet El. As it rises the piston forces liquid above it through the slot F<2> and causes reverse flow through the part of the strainer corresponding to the section B<1>. When the parts are turned to bring an aperture All to communicate with the outlet E<1>, the piston descends and forces liquid below it through the slot Fl to give a reverse flow from the section B<2>. In a modification of this form the communication of the apertures All, A<12> with the outlet E4 is so arranged that there is a filter flow through both sections except during periodic cleansing. The strainer shown in Fig. 12 is formed by winding a wire helically on a grooved body, the grooves being divided by a rib A<9> into two sections which communicate through apertures A<10>, A<11> respectively with upper and lower sections B<1>, B<2> of the body. The sections are separated by a piston b carrying a central tube J<2>. With the piston in the position shown normal filtering flow takes place through both sections, but when it is moved longitudinally by the spindle C the tube J<2> slides within an upper tube J or a lower tube J<1> and cuts off the upper or lower section from the outlet so that a reverse cleansing flow takes place through the section cut-off. Fig. 18 shows a straining cylinder suitable for use in the arrangement shown in Fig. 1. The strainer is formed by a helical coil A<1> on a body A which is ribbed and perforated. The fluid straining into the sections B2, B4 passes along directly through apertures b2, b4 while that straining into the sections B<1>, B<3> passes. through pairs of apertures r<1>, r<2>, normally opposite blades b<1>, into the sections B<2>, B<4> respectively. Figs. 18a and 21 show apparatus comprising a number of cylindrical strainers clamped between a headpiece Q and a baseplate Q<1> about a central cylinder M into which the filtrate passes from the strainers through apertures M<1>, M2. The cylinder is provided with blades b<1>. Grooves R<2>, R<3> allow of communication between the sections B2, B3 and the sections Bl, B<4> respectively.