November 1, 2001
Fines Separator DesignedTo Remove Light ImpuritiesFrom Coarse Plastics
T&T's high-capacity gravitational Fines-Sep BULK series is turnkey-engineered and designed to operate without water, moving parts or vibration. Units in the series range in capacity from 5000 to 40,000 lb/hr.
According to T&T's Bernhard Groth, the impact that fines can have on a process is usually dependent on humidity and vibration. Thus, in the past, only sporadic symptoms of fines build-up alerted the processor to evaluate his plant-wide material handling methods.
Fines particulate can be as diverse as snakeskin, angle hair, dust, fluff, cardboard or paper. Typical problems associated with fines include the attraction of moisture, airborne contaminant particles, build-up of static electricity, uneven melt distribution, black spots in the finished product and clogged vacuum filters and dryer desiccant beds.
Groth says the Fines-Sep BULK series gently air-washes and separates particles with high surface areas from particles with low surface areas. A manual airflow adjustment version is a standard feature. An ac inverter-powered version is optional.
Depending on the electrical properties of the plastic to be processed (known as surface resistivity), the use of T&T's Static-Sep add-on module will further enhance the dry separation process. By continuously releasing free ions into the air stream of the fines separator, the Static-Sep module is designed to ensure that the electrostatic bondage between the heavy and the light particulate can be mostly abated. Thus an optimal efficiency with sharp separation effectiveness of up to 99.99 % can be achieved.
Applications and benefits cited for the T&T Fines-Sep BULK system include:
Virgin material: same grade from different lots. Virgin pellets originating from the same supplier should be fines-free. Unfortunately, this is not always the case, particularly due to friction of brittle plastics shipped in bulk trucks or rail cars and sometimes in Gaylords
Virgin material: equal type and grade but from different suppliers. By applying the T&T fines separation method, a processor can quickly compare particle distribution, possible fall-off in molecular weight and other issues that result when material is received from different vendors.
Use of regrind: For various reasons, not every processor makes use of in-house regrind. It is known that granulated material will never have the uniform particle size of virgin pellets. This affects the bulk density and the feeding characteristics in processing. Large particles are difficult to feed, particularly in small-diameter screws, where channel depth is not adequate enough to accommodate the size of large particles.
The Fines-Sep BULK system comprises the following components:
An aerodynamically designed air-washing compartment with a dual-cascade assembly. Each cascade assembly is equipped with a set of ambient air inlet slots, and a set of exit air slots for the air-washed airborne impurities.
A dual digital gage to precisely monitor the air flow volume during the air-washing process. It is equipped with manual air flow adjustment and an ac inverter-powered version is optional.
A PLC-powered central control panel.
An assembly of a single-stage, reverse-flow fines cyclone receivers, a 'whisper-quiet' industrial suction fan and a dust collector.
A top-mounted rotary airlock assembly with 'Y' tube material distribution channels.
A stainless steel surge bin with material level indicator and bottom-mounted rotary airlock assembly.
Options include: electro-staticneutralizing module operating without water, vacuum pressure loading and unloading system and an environmentally friendly central bag house tosafeguard plant air from possible excess fines-laden air.
T&T Technology & Trade, Inc.
Chicago, IL Circle 111
You May Also Like