Stock inlet for paper/cardboard pulp delivery has a flexible wall section at the flow channel walls to the outlet gap to compensate for pressure changes to maintain a constant gap width

摘要

The delivery jet (10) of a stock inlet, for the feed of a fiber suspension pulp to a papermaking or cardboard prodn. machine, has a relatively flexible wall section (20) at least at one of the flow guide walls (16,18) across the machine width. It has a bending compensation system to maintain a given delivery gap width, to develop an external force (F1) according to the inner force (P1) in the jet delivery channel (14) and/or at least one support supports the flexible wall section (20) against a relatively rigid base body (24) of the flow guide walls (16,18), to compensate for any bending on either side of the support in the flow direction at the flow gap zone. The flow channel (14) is divided into sections across the machine width, and the external force (F1) is also generated in sections. The flexible wall section (20) is fitted to the base body (24) of a flow guide wall (8) at its end (22) away from the outlet gap (12). The external force (F1) is generated by pressure between the flexible wall section (20) and the base body (24), at the outlet gap zone (12) of the structure. The effect on the flexible wall section (20) can be through a membrane at the base body (24), where a pressure fluid can be introduced between the membrane and the base body. The generated external force (F1) is developed by a control circuit, according to the internal pressure (P1) within the flow channel (14). The wall support is between the flexible wall section (20) and the base body (24), at the outlet gap (12) zone. The support is cylindrical, and pref. a circular cylinder shape, along the line of the machine width.