Patent GB-300194-A (GB)
Title: An improved process and apparatus for the production of a puffed product and the product obtained therefrom
IPC: A23L1/00
Filed: 1928-08-23
Abstract: 300,194. Anderson Puffed Rice Co., (Assignees of Anderson, A. P.). Nov. 8, 1927, [Convention date]. Extrusion machines.-A puffed product is made by applying heat and pressure to moisture-containing material reduced to a state in which it will flow under pressure, the treated material being released through an annular orifice to permit the moisture to vaporize and so puff the product. The continuous tube so formed may be cut up into short lengths in such a manner that the ends of the pieces are simultaneously closed and these pieces may then be toasted. The materials treated may be cereals, tubers, fruits such as green bananas, or non-edible material. The material, admixed with a vaporizable liquid and, if desired, impregnated with a gas under pressure, is placed in a container 30 from which it is forced by mechanical pressure into tubes 41 extending through a steam heated cylindrical steel shell 42. From the tubes 41 the material passes into cooking tubes 53, preferably of slightly smaller diameter, encased in a steam-jacket 50 fed with steam under pressure through pipes 57, and escapes into a header where the individual strips issuing from the several pipes mix and pass into a single outlet pipe 56. The header is shaped to prevent accumulation of material in " dead " spots. The pipe 56 feeds the material to an extruding nozzle 60 contained in a chamber 70 that is substantially square in cross-section and is heated up to about. 575‹ F. by a current of hot air, electric resistances or by hot gases or steam passing through hollow walls. The extruding nozzle 60 is formed with two chambers 62, 63, connected by a narrow slot 64 to ensure that the material is intimately mixed, the lower chamber being provided with an annular outlet 65. A pin 69 forming the centre portion of the annular outlet is held in position by a pin 66 and protuberances 67 and is made hollow at its lower end. The nozzle is formed of bronze or nickel and may be plated upon its exterior with a non-corrodible metal such as gold, platinum or chromium. The screws holding the parts of the nozzle together are of steel to ensure a tight joint by reason of the difference in the coefficients of expansion of steel and of bronze. The initial pressure given to the material is about 5000 lbs. per square inch and this pressure falls to about 4000 lbs. per square inch at the slot 64. The extruded material falls through a funnel 71 into a second funnel 72 which can be turned by a. handle to direct the material through a door in the side of the chamber 70. Glass doors are provided to permit observation of the material in the chamber. The extruded tubes are cut into lengths and closed by a cutting roller 111 working against a platen roller 110 the bearing blocks of both the rollers being adjustable by springs and screws to enable them to be accurately positioned. The roller 111 carries a number of knives 112 supported by springs 114 in slots. The Specification as open to inspection under Sect. 91 (3) (a) states also that the extrusion nozzle may be so shaped that the extruded material is round, square, polygonal, oval or rectangular instead of annular in cross-section. This subject-matter does not appear in the Specification as accepted.