Particle quantifying apparatus and method

An apparatus for estimating the quantity of particles on at least a first surface of a web traveling through a collecting area, comprising:

• an air suction extractor including a first particle collecting head having an air intake disposed within the collecting area in close proximity to the first web surface and coupled to an output air carrying line connected to an air suction source to convey collected particles through said output line;
• a capturing element handling assembly including first and second stationary elements disposed in a spaced relationship to define a gap therebetween, said stationary elements being provided with respective sets of main apertures disposed in alignment with each other to define a corresponding set of channels extending through the gap, a movable element interposed within the gap and being provided with a plurality of holders capable of receiving a plurality of filter-type particle capturing elements, and an actuator operatively coupled to the movable element for providing controlled movement of the movable element relative to the stationary elements, wherein one said main aperture on the first stationary element defines a first inlet in fluid communication with the output fluid carrying line and one corresponding said aligned main aperture on the second stationary element defines a first outlet for fluid communication with the output fluid carrying line through a corresponding said channel;
• an optical sensing device disposed in alignment with a secondary aperture provided on the first stationary element and extending therethrough to communicate with the gap, for inspecting a selected one of said particle capturing element to generate a measurement signal representative of optical characteristics of the collected particles as captured by the selected element;
• a data processor for analyzing the measurement signal to generate an estimation of the quantity of particles captured by the selected element;
• and
• a controller operatively connected to the actuator to selectively displace the movable element from a first position wherein one of said two holders is aligned with the first inlet and outlet so that correspondingly received said particle capturing element captures the particles during a first predetermined period of time, to a second position where said one holder having the selected capturing element received therein is aligned with the secondary aperture so as to be inspected upon operation of the optical sensing device.

A method for estimating the quantity of particles collected by a suction extractor through an output fluid carrying line provided thereon, comprising the steps of:

• i) interposing a first filter-type particle capturing element within said output fluid carrying line during a first predetermined period of time to capture a corresponding quantity of said collected particles;
• ii) inspecting the particle-capturing element with an optical sensor during a second predetermined period of time to generate a measurement signal representative of optical characteristics of the collected particles as captured by the element;
• iii) analyzing the measurement signal to generate an estimation of the quantity of particles captured by the element;
• iv) circulating a cleaning fluid through the first particle capturing element in a direction so as to remove said quantity of collected particles;
• and simultaneously to said step iv):
• v) interposing a further filter-type particle capturing element within said output fluid carrying line during a further said first predetermined period of time to capture a corresponding further quantity of said collected particles;
• vi) repeating said steps ii) and iii) with the further particle capturing element.

A method for estimating the quantity of particles on at least a first surface of a web traveling through a collecting area, comprising the steps of:

• i) applying suction within the collecting area in close proximity to the first web surface to collect said particles and convey thereof through an output air carrying line;
• ii) interposing a first filter-type particle-capturing element within the output fluid carrying line during a predetermined period of time to capture a corresponding quantity of said collected particles;
• iii) inspecting the first particle-capturing element with an optical sensor to generate a measurement signal representative of optical characteristics of the collected particles as captured by the element;
• iv) analyzing said measurement signal to generate an estimation of the quantity of particles captured by the element;
• v) circulating a cleaning fluid through the first particle capturing element in a direction so as to remove said quantity of collected particles;
• and simultaneously to said step v):
• vi) interposing a further filter-type particle capturing element within the output fluid carrying line during a further said predetermined period of time to capture a corresponding further quantity of said collected particles;
• vii) repeating said steps iii) and iv) with the further particle capturing element.