GB515442A - Improvements in or relating to gas-proof shelters - Google Patents

Abstract

515,442. Construction and ventilation of gasproof shelters. ATWILL & SON, Ltd., R., HOLFORD PROCESSES, Ltd., HOLFORD, H. J., and WHITE, H. F. June 1, 1938, No. 16428. [Classes 20 (i) and 137] The shelter is provided with air-tight doors and air circulating and filtering means extending within the chamber, an induction fan associated with the filter in the inlet and an extraction fan arranged in the air outlet. A gas proof, and blast proof air raid shelter, adapted also for use as a garage has a pyramidal roof 11, and is mounted on a concrete raft 12, the sides being made of reinforced concrete, and the interior covered with moisture absorbent material such as wall-board. A vestibule 13 is provided at one side, and at the opposite side are, armour plated doors 16 are lined with " Plymax " and packed with silicate cotton and activated charcoal for insulation. The vestibule has inner and outer doors 20, 18 between which are arranged fireproofed blanket - screens' 22. Windows 23 are constructed of glass bricks of " Insulite," and an air inlet and outlet 32, 36 with armour plate covers are provided, the inlet having a cylindrical metal housing containing two filters 46, and a fan 40 which induces filtered air into the shelter. Fig. 5 shows an assembly of fans and filters in the outlet and in the inlet opening, one fan 56 drawing in air through a filter 62 and delivering-filtered air through a pipe 64 and branch 66, the extraction fan 68 removing air by pipe 76, and delivering it through a filter 78 and outlet 36. The fans may be driven either by a motor 88 or by pedal drive 90, or by both. The driving means are both reversible so that the fans may be driven in opposite directions to facilitate the changing of the filters, each of which may comprise a frame 98 and gauze 100, Fig. 8, enclosing the activated charcoal and asbestos-merino wool. A colour changing gas indicator 104 shows when replacement is necessary. The activated charcoal and wool may be supplied in a carton 106, Fig. 9, having perforated sides. Provision is made for bye-passing the filters so as to supply unfiltered air when required, and an air-flow meter 118 is provided, with a counterbalanced float 122 in the air inlet pipe.