GB890459A - Sealing means for floating roof tanks - Google Patents

Abstract

890,459. Tanks. WYATT INDUSTRIES Inc. May 18, 1960, No. 17520/60. Classes 54 and 69 (1). Sealing means for a floating roof tank 20 has a sealing element which closes the space between the roof and wall of the tank and which is urged into sealing engagement by bowing a flexible beam 84 by expanding means which reacts on the beam's ends. The tank 20 is cylindrical and the roof comprises a thin conical raft supported by an annular caisson around its edge (Fig. 1, not shown). The caisson is divided into bulkheads whose outer walls form the inner wall of a crawl-gallery to whose outer wall 75 and roof 79 are bolted at 104 and 105 the edges of a sheet of rubber fabric sealing material 27-49-28 (Fig. 8). Part 49 of the fabric is held against the tank wall by a series of spaced flexible metal plates 85 mounted on shoes 40 which are on pivoted arms 72 spring- loaded at 76. Alternatively, to the spring 76, the space inside the crawl-gallery may be ballasted with fluid whose pressure holds the shoes and the fabric against the wall (Fig. 10, not shown). Alternatively also, the outer side of the fabric in the region of the shoe 40 may have externally fluid-filled hollow contact ribs circumferential of the tank (Fig. 11, not shown). The beams 84 are carried between vertical rollers 82 and clips 68 bolted on to the shoes 40, Fixed inside the wall of the tank and evenly spaced between sets of shoes are six vertical rails 35, shown in section in Fig. 3 on which guide-boxes 36 can rise or fall to conform with the fluid level in the tank. The boxes 36 are expansibly connected to the roof by H beams which project radially inwards from them and are held between two pairs of vertically superimposed rollers 55 and 56 which suspend below the floor of the crawl-gallery (Fig. 4, not shown). Other rollers 50, 51 centre the boxes 36 on the racks. The boxes also confine resilient blocks 44, 45 which anchor the ends 48 of the fabric 49 and whose sides are urged inwards by leaf springs (Fig. 7, not shown) to grip the rail. Fluid motors 94 are pivoted on either side of a plate 97<SP>1</SP> on each box 36 and connect with the ends 90 of the beams 84, where they are supported by a roller 89 running along rails extending laterally from the shoes 40. Fluid pressure is supplied from a source on the roof (Fig. 1, not shown) to cause the rams 92 of the motors to bow the beams 84. In another embodiment (Fig. 14, not shown), pairs of motors are mounted, connected back-to-back, on adjacent shoes and the rails 35 and boxes 36 are omitted. In another embodiment the beams are supported against the tank wall on arms which are pivoted to the roof top and are carried in the inwardly directed channels of shallow U-girders running right round the tank sides. In this instance the beam is bent by pressure from multiple coil springs which are pivoted at their fixed ends to the roof of the tank.