ES374861A1 - Pneumatic fiber conveying system - Google Patents

Abstract

Fibres carried by an air stream are distributed to a plurality of machines from a main trunkline 101 via a plurality of branch ducts, such as 102, the fibres being diverted into the branch duct 102 by means of a gas jet 128 disposed upstream of the branch duct and arranged to direct a jet of air against one wall of the trunkline 101. The fibres can be fed to opening, blending, cleaning, carding and random web-forming machines. As shown, an adjustable air jet 128 is arranged at an interaction chamber 120 of enlarged cross section in the trunkline 101. The fibres diverted into the branch duct 102 are collected in the trumpet shaped area between adjustable metering roll 107 and plate 108, then fed to foraminous condenser drum 100 and then to a web forming machine via roll 119, 121. The fan 105 used to generate the suction in condenser drum 100 is used to feed the air jet 128. As the fibres collect in the duct above the metering roll 107 the output of the fan 105 is reduced and less fibres are diverted into the duct 102, thereby automatically maintaining duct 102 full. The metering roll may be omitted with the trumpet shaped area being formed by the condenser drum (Fig. 11). The wall of the branch duct may be flexible to assist control of the fibre flow (Fig. 12). The fibre stream diverting jet can be arranged to divert the fibre stream into either of two secondary branch ducts upon passing a single air pulse through one of two control jets (Fig. 3). Alternatively, two fibre streams can be passed to one of two respective branch ducts depending upon whether control pulses are present at one or both of the respective control jets. (Fig. 4). The outlets can be combined to blend the output fibres. Alternatively, one fibre stream diverting jet (80 or 84) can also control a second diverting jet. The second diverting jet has a further independent control port 88, (Fig. 5). The fibre feed to the main trunkline can be via a pneumatic conveyor (126) feeding a spiked opener (138) via a tapering hopper having vertical wall (133) moving downwardly over a section box. The fibres are blown off the opener into the main trunkline by fan (139). The return duct 140 from the main trunkline feeds into a similar hopper and brush wall opener which passes surplus fibre back to the trunkline. An electrical metering device (158) positioned upstream of both opener outlets determines the rate of feed of new fibres from the hopper feeding the opener (138).