Processing Technologies & Equipment Flashcards
6 cards from real CRP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Processing Technologies & Equipment flashcards as text
What is the primary function of an eddy current separator in a MRF?
Answer: To repel and separate non-ferrous metals (primarily aluminum) from the conveyor stream using a rapidly alternating magnetic field
An eddy current separator creates a rapidly alternating magnetic field that induces repulsion in non-ferrous metals like aluminum, ejecting them away from non-metallic materials.
Which MRF equipment uses near-infrared (NIR) technology to identify and sort materials?
Answer: Optical sorter
Optical sorters use NIR spectroscopy to identify polymer resin types and paper grades by their unique light absorption signatures, then use air jets to divert target materials.
What is a 'trommel screen' used for at the front end of a MRF sorting line?
Answer: Screening out small fines, broken glass, and contaminants that would interfere with downstream sorting equipment
Trommel screens rotate a drum with holes that allow small materials (fines, broken glass, dirt) to fall through, cleaning the stream before it reaches optical sorters and other sensitive equipment.
What is the purpose of a 'ballistic separator' in a single-stream MRF?
Answer: To separate 2D flat materials (paper/cardboard) from 3D containers using spinning paddles that throw lighter flat items up and roll heavier containers down
Ballistic separators use rotating elliptical paddles that propel flat 2D materials (like paper) up a screen while 3D containers roll down and off, separating these two major stream components.
Which MRF processing problem is most directly caused by 'tanglers' such as plastic bags, hoses, and wire?
Answer: Wrapping around rotating equipment shafts and screens, causing jams and requiring costly manual cleaning downtime
Flexible film and wire tanglers wrap around the shafts and paddles of screens, balers, and conveyors, causing frequent jams that require workers to shut down and manually cut material free.
What is the 'residue rate' at a MRF, and why is it a key performance indicator?
Answer: The percentage of incoming material that cannot be recycled and is sent to disposal, indicating overall sorting efficiency
Residue rate measures what percent of total incoming material ends up as landfill-bound waste after sorting, directly reflecting the MRF's efficiency and the cleanliness of the incoming stream.