System and method for treating biomass material

A cleaning system for a biomass material treatment stage in a continuous process system, wherein the biomass material treatment stage includes a hydrolysis or pre-hydrolysis reactor, a feeding arrangement is arranged to continuously feed biomass material to an inlet of the reactor, the reactor includes a reactor screw for moving the biomass material through the reactor and a discharge pipe including a discharge screw for continuously discharging treated biomass material, said cleaning system comprising:

• at least one high-pressure cleaning nozzle arranged inside a housing of said reactor, wherein said at least one high-pressure cleaning nozzle is arranged to eject cleaning agent at predetermined intervals during operation of the reactor and at a pressure within a range of 15-225 bar to the reactor screw during operating of the reactor;
• and
• wherein said at least one high-pressure cleaning nozzle is arranged to eject cleaning agent towards a leeward side of the reactor screw so as to impact a leeward side of screw threads of the reactor screw;
• wherein said at least one high-pressure cleaning nozzle is arranged to eject cleaning agent to the reactor screw with an angle between an inner wall of the housing and a central line of a ray of cleaning agent within a range of 10-170 degrees;
• and
• wherein said at least one high-pressure cleaning nozzle is arranged to deliver cleaning agent at a flow within a range of 1.0-6.0 L/min.