Method of controlling a dosing and mixing system of a product with several components, dosing and mixing system of said product, and spraying or extrusion installation comprising such a system

摘要

Control method of a dosing system and mixing of a product composed of two components, namely a first component (4) and a second component (5) intended to be mixed in a mixer (3) at a predetermined dosage rate , the system comprising two pumps, namely a first alternative double acting pump (1) suitable for feeding the first component (4) in the mixer (3), and a second alternative double acting pump (2) suitable for feeding the second component (5) in said mixer (3), the piston displacement of each pump (1, 2) being inverted from a direction of aspiration and expulsion of the corresponding component (4, 5) to a direction of ejection of the component , and vice versa, the process comprising the phases consisting of: - operating the first pump (1) to feed the first component into the mixer (3); - operate the second pump (2) to feed the second component into the mixer (3) · according to said predetermined dosage ratio; - continuously determine the volume remaining in each pump (1, 2), and - activate the reversal of the piston of a pump (1, 2) after determining that the volume remaining in the pump (1, 2) in the direction current of expulsion or aspiration and expulsion is insufficient to ensure said predetermined dosage ratio, and in which - the feeding of the first component (4) in the mixer (3) from the first pump (1) is a feeding continuously ensured during the entire operation of the dosing and mixing system, - the feeding of the second component (5) in the mixer (3) from the second pump (2) is an intermittent supply to carry out feed cycles of dose of the second component, in order to maintain said predetermined dosage ratio, and - the second component (5) is fed by the second pump (2) with an overpressure with respect to the pressure at which the first component It is powered by the first pump (1).