Method and regulation arrangement for controlling dewatering profile of a former

A method for controlling the dewatering profile in a former of a paper or board machine, comprising the steps of:

• removing water from a web between a first forming wire formed into a first loop and a second forming wire formed into a second loop, wherein a forming roll is placed within the first forming wire loop, and a blade element is placed within the second forming wire loop, the blade element extending transversely across the web with respect to the running direction of the wires;
• measuring the cross-direction profile of a flow channel defined between the forming roll and the blade element by passing an alternating current of low frequency through a current rail situated in the blade element and measuring the strength of the magnetic filed generated by the rotation of the forming roll by at least two measuring devices;
• and
• adjusting the location of the blade element based on the measurement result in order to regulate the thickness profile of a stock flow.

A regulation arrangement for controlling the dewatering profile in a former of a paper or board machine, the arrangement comprising:

• a first forming wire loop;
• a second forming wire loop, wherein the first forming wire loop and the second forming wire loop have dewatering elements placed inside them, wherein at least one os said dewatering elements comprises a blade element which extends transversely across the web with respect to the running direction of the forming wire loops and is in contact with one of the forming wire loops;
• members for measuring the cross-direction profile of a flow channel defined between a first dewatering element situated inside the first forming wire loop and a second dewatering element situated inside the second forming wire loop;
• and
• members for adjusting the location and/or the position of the blade element based on the result of measurement of the profile of the flow channel.