Adjusting apparatus, adjusting system, crusher, crushing plant and method for adjusting the crusher

A crushing plant comprising:

• a pressing mineral material crusher comprising a crushing chamber, a feed opening of the crushing chamber, and a measuring means for measuring at least one of crushing power used, a crushing pressure and a surface height of mineral material in the crushing chamber, wherein the crusher comprises an adjusting apparatus comprising a body and a plurality of adjusting parts each bearing-mounted at their first ends to the body by rotating axes and second ends of the plurality of adjusting parts are rotatable around the rotating axes, wherein curved front edges of the adjusting parts form a single unitary flow opening having a flow area which is adjustable by moving the plurality of adjusting parts, and wherein the plurality of adjusting parts are arranged such that the curved front edges form a perimeter around the flow area of the flow opening, and the flow area is adjustable by moving the plurality of adjusting parts, and the plurality of adjusting parts are configured to move such that the flow area is decreasing when at least one of the crushing power, the crushing pressure and the surface height measured by the measuring means is increasing and the flow area is increasing when at least one of the crushing power, the crushing pressure and the surface height measured by the measuring means is decreasing.