MOULD TO BE USED FOR COMPACTING PELLETS

Abstract: The invention concerns an annular mould (1) for producing pellets in the form of short bars with a triangular cross-section. The pellets are formed by the pressing action of rollers (2) on the inside (3) of the mould (1) where the powdered dry ice (carbon dioxide) is forced through radial holes. The holes have a converging intake, a channel with mainly parallel sides and a widening outlet. It is possible to have partitions with provisions to break the bar into short pellets.

Description: Kould to be used for compactin pellets. The invention concerns ar. annular mould as used in so-called pelietiser where powder through radial holes in the annular mould is pressed rollers. By breaking off the bars which are formed this way short piece with the profile of the hole in the mould are formed. The subject moul of the invention is a special means to compact carbon dioxide powde (solid CO-- at a temperature below minus 56°) into tough bars with triangle cross section. These bars are very suitable to be used fo cleaning surfaces by spraying. It has been proved that the sprayin material stays sharp even when some sublimation occurs by the sprayin action. The treatment of surfaces with carbon dioxide particles is known fro the American patent Nr. US-A-4389820. It is found that the normal proce of compressing and crushing of solid carbon dioxide results in irregula and blunt spraying material. The subject of the invention is a mould to produce small bars of heav compressed carbon dioxide with a triangle cross section. The mould ha the form of a ring and is used in a machine where rollers on the insid of the ring press the powdered carbon dioxide into radial holes. Thes holes are narrowing and converge into a channel with a triangle cros section. The end of the channel carries means to break the bars, The invention is described with the help of the drawings. Fig. 1 shows the mould and the rollers. Fig. 2 shows a cross section of the mould at the position of the holes. Fig. 3 shows the inside of the mould. Fig. 4 shows the outside of the mould. Fig. 5 shows the cross section of the space between two holes, Fig. 6 shows the cross section of the partition between two triangul channels, Fig. 7 shows a pellet produced with the mould. Fig. 8 shows an alternative pattern of hales. In Fig, 1 (1) is the annular mould and (2> the rollers which roll alo the inside (3). Centerlines (4> indicate schematic the position of the holes (5). Fig. 2 shows that the holes (5) have a converging part (6) that converts in a mainly triangle channel (7) with mainly parallel sides (8). At the end of the channel C7) is a widening outlet (9). At (10) is indicated that two holes (5) are connected into one hole while the channels (7) are formed by a partition (11). The partition (11) is chamfered (12 ) at the entry. On the outlet the partition Cll can have a breaking edge (13) which breaks the bars of compressed carbon dioxide. In Fig. 5 is indicated how walls (14) between holes (5) and (10) are chamfered (15). In Fig. 7 is shown a spraying particle (1 ^ produced with a annular mould (1) according to the invention. The pattern of the holes (5) and (10) is concentrated in the middle section (16). The area's (17) along the edge of the inside surface (3) are provided with shallow grooves (18). These grooves (18) prevent jamming of the machine in case of superfluous supply of carbon dioxide. Fig. 8 shows an alternative pattern of singular holes (5),

Claims: Claims. 1] Annular mould for producing by pressing particles meant for cleaning of surfaces by means of spraying characterised in that the mould (1) on the inside (3) is provided of holes (5) and (10) in radial direction which converge to mainly triangle channels (7) with mainly parallel sides (8) which convert into a widening outlet (9) on the outside surface of the mould. 21 Annular mould for producing by pressing particles meant for cleaning of surfaces by means of spraying as in claim 1 characterised in that a part of the holes (5) are combined in two's with a partition (11) between the triangle channels (7) and together with the singular holes (5) form a pattern of nearby placed holes (5), (10) in a disk (16) which is about in the centre of the ring (1). 31 Annular mould for producing by pressing particles meant for cleaning of surfaces by means of spraying as in claim 1 and 2 characterised in that the partition (11) between triangle channels (7) on the side directed to the centre is provided with chamfers (12) and on the side of the outlet (9) is provided with a breaking edge (13). 41 Annular mould for producing by pressing particles meant for cleaning of surfaces by means of spraying as in claim 1, 2 and 3 characterised in. that the inside surface (3) of the ring is provided with grooves (18) which reach from the edge to close to the holes (5), (10), 51 Annular mould for producing by pressing particles meant for cleaning of surfaces by means of spraying as in claim 1, 2, 3, and 4 characterised in that the mould (1) is used to compress dry ice (powdered solid C0 2 ) into short bars (19) with a triangular profile.

Inventors: KONINGS HUIBERT, KONINGS, HUIBERT
Applicants: HARKO BV, HARKO B.V.
Application year: 1991
Main classification: C01B31
IPC codes: B01J2, B24C1, B30B11, C01B31