Suction nozzle, jet suction box and jet suction method

A suction-extraction device of a hydroentanglement device for a hydroentanglement of a moving fibrous material web with liquid jets, the suction-extraction device comprising:

• a jet suction box that is intended and configured to suck the liquid jets, which are emitted by the hydroentanglement device and are discharged again from the fibrous material web, in a suction flow, the jet suction box comprising:
• a box casing having at least one slot casing opening leading to a box interior space;
• and
• at least one suction nozzle at the box casing, the at least one suction nozzle comprising:
• a nozzle body arranged above the slot suction opening, with a slot suction opening passing through the nozzle body, the slot suction opening having an inlet side that is directed outwards relative to the box casing and an outlet side directed towards the slot casing opening, wherein the slot suction opening extends along a suction flow direction from the inlet side at a free end of the nozzle body to the outlet side at the at least one the slot suction opening;
• at least one mobile sealing element on the inlet side of the nozzle body, the at least one mobile sealing element being arranged adjacent to the slot suction opening and laterally defining the slot suction opening;
• and at least one resilient expansion device acting on the sealing element, the least one resilient expansion device being configured to push the sealing element away from the outlet side against the suction flow direction;
• and
• a liquid-permeable conveying device for moving to convey the fibrous material web, wherein the jet suction box is arranged relatively stationarily in relation to the conveying device and wherein the at least one mobile sealing element is sealingly in contact, at an outer side of the at least one mobile sealing element, with the conveying device.