GB764408A - Fly-ash injection apparatus - Google Patents

Abstract

764,408. Sorting solid materials; magnetic separators. RILEY STOKER CORPORATION. Jan. 10, 1955, No. 683/55. Class 117 [Also in Group XII] In the boiler furnace installation shown, com bustion products dis charged therefrom are passed to the stack 33 via a fly-ash collecto: 31. From this collecto: the ash gravitate downwardly through a gravity separating ap paratus 43, a magnetic separator 47 and a limit ing apparatus 50 the larger particles of asl which are stated to be of high carbon content) which finally pass through the duct 52 being injected by steam or air into the furnace through the nozzle 56. It is stated in the Specification that large particles of fly-ash are of high carbon content and non-magnetic whilst the small particles are of low carbon content and magnetic. The first of these properties is used in the apparatus 43 the large particles being compelled to pass to the duct 46 whilst duct 44 carries the smaller ones. In the magnetic separator magnetic particles are attracted down the duct 48 whilst the non-magnetic ones pass to a limiting apparatus 50. This ensures that the duct 52 is always full compelling the overflow to pass to the duct 51. All rejected ash is collected at 57 and eventually ejected into the ash pit 25. Fig. 2 shows a form of gravity separator 43, fluting 74 being so arranged in a casing 72 that small particles are caused to pass to the reject duct 73 whilst the larger ones travel via duct 77 to the magnetic separator. In the separator of Fig. 5 an intermittently operated electromagnet 96 causes magnetic particles to be attracted to the reject duct 94 leaving the non-magnetic ones to pass to the limiting apparatus via duct 95. Alternatively, the particles falling down a duct 101, Fig. 6, are deflected by a vane 104 and the magnetic particles are attracted by an electromagnet 105 and fall into a duct 103. In the separator of Fig. 7 the particles are carried by a current of air through a duct 110 and the magnetic particles are deflected by an electromagnet 113 into a duct 112. Fig. 8 shows electromagnetic coils 124 surrounding a duct 121 through which the particles flow in a gas stream from the left; magnetic particles are attracted towards the duct walls and pass into a duct 122, whereas the non- magnetic particles pass into a branch 123. In the apparatus of Fig. 4, separation of fly-ash is effected by the smaller particles being caused to flow around a vane 86 into a hopper 84 by the suction on a conduit 85 brought about by the action of the ejector to the ash pit.