GB1465938A - - Google Patents

Abstract

1465938 Circular tunnel kiln for concrete products BESSER CO 29 Aug 1974 [5 Sept 1973 1 Aug 1974] 37730/74 Heading F4B A circular tunnel kiln K (Fig. 1) for curing moulded concrete products has bulkheads 14- 22 which divide the kiln into compartments 23-30. Mounted around the circular base 13 (Fig. 3) of the kiln are pedestals 31 with rollers 34 and 35 that support a circular chassis assembly C (Fig. 1) that is indexed round the kiln a distance d (Fig. 6) by two hydraulically operated units I (Fig. 1) in uniformly timed manner. The chassis assembly C is constructed of arcuate sections A (Fig. 9) secured together. The sections A comprise tubular members 36 and 37 joined by channel members 37a and 37b and with bar members 38 and 39 including thrust blocks 41 for engagement with indexing units I secured to the undersides of members 37a and 37b. Wedge-shaped racks R (Fig. 6) with solid top and bottom plates 45 and 46, solid end plates 45a and 46a and a solid partition 47 are secured to the channel members 37a. The racks R have shelf members 47a (Fig. 3) to support pallets P which in turn support the concrete products which are loaded and unloaded at the stations L and U (Fig. 1). At each end of the bulkheads 14-22 are wiper blade assemblies W, with resilient wiper units (50), (51), Figs. 7 and 8 (not shown), that engage the solid plate surfaces of the racks R as they pass through. The wiper blade assemblies are so constructed in relation to the dimensions of the racks R and the indexing distance d that as the racks move round the kiln a seal is always maintained between the wiper blade assembly and one of the racks, thus ensuring a seal between the individual compartments 23-30. Hot oil from the heating unit 79 is supplied via the manifold 81 to the air supply heater assemblies H (Fig. 2). Air for compartments 23 and 24 is heated in the units H and circulated round by fans 84 which are thermostatically controlled to maintain the compartments at the desired temperature. Compartments 25-28 are similarly supplied with thermostatically controlled hot air, but in addition a humidistat controls a supply of steam which is injected into the air stream by nozzles 89. Compartment 29 is a bleed off chamber for steam vapour and no heater unit is utilized and compartment 30 is cooled by ambient air from the fan 90. An improved version of the invention has wear strips (100), Fig. 14 (not shown), welded to the lower surfaces of the circular chassis assembly tubular members 36 and 37 and the rollers 34 are mounted in pairs with restricted universal movement.