Rieter

Suction system machine

Index

Fig. 42 – Negative pressure drive

The main fan (Fig. 42, 1) sucks the air from each spinning position through negative pressure duct (2) and filter housing (3), thus creating a negative pressure of approx. 60 - 85 hPa at the rotor housing of the  spinning box. Trash, dust and fiber fragments carried by the air current are collected by a filter layer (4) in the filter housing. The layer of fibers, trash and dust is held on the filter by the current of air. However, as the filter becomes increasingly full, the negative pressure inevitably weakens. If the negative pressure then falls below the adjustable limit value (alarm level), the current of air is automatically diverted briefly through a bypass (5). The layer of material on the filter is now no longer held and drops onto the base of the filter housing (6). The negative pressure is thus restored in full.

Another option for offsetting the decline in negative pressure for spinning with increasing filter coating is to keep the negative pressure constant, i.e. fan speed and thus the negative pressure are continuously increased as the filter coating increases. Negative pressure for spinning is continuously monitored by sensors and adjusted according to filter loading. However, power consumption also increases with rising fan output. There are therefore also limits here, and when these are reached the filter coating must be removed manually. The burden on operating personnel is also relieved considerably with this concept by extending the intervals between manual emptying of filters. In addition to negative pressure for spinning, the fan generates the suction required to dispose of the trash removed from the spinning box. The trash resulting from extraction from the spinning box is deposited on a trash conveyor belt and fed to the filter by suction nozzles at the left-hand and righthand ends of the machine. The suction nozzles are controlled in such a way that only the suction nozzle toward which the conveyor belt is moving is operating. If the belt changes its direction of movement, the currently active suction nozzle is closed and the suction nozzle on the opposite side of the machine is switched on.