Swarf and Turnings Degreasing and Washing Machines
Swarf produced from machining operations is contaminated with oils, emulsions, metal dust and water, to reprocess and recycling the swarf it needs to be clean and dry. Rotajet manufacture size reduction, washing and degreasing systems. Typically Rotajet supplies the swarf recycling systems for processing high value super alloys. The systems are used to size reduce, degrease and dry the alloys prior to processing in vacuum furnaces.
Size reduction and chipping of Swarf and turnings:
The swarf is normally tangled together and generally acts as a bulk mass. To process the swarf, the material needs to be sized reduced into 10-20mm chips, this not only allows the material to be easily conveyed and process, but also increases bulk density. The size reduction is carried out using a Four shaft shredder fitted with high torque motors and hardened blades. The four shaft shredder is fitted with easy to change screens. Once the material is swarf is shredded, the chips fall through the screen onto a Rotajet swan neck conveyor. The Rotajet swan neck conveyor is fitted with a flighted belt, and Rotajet overband magnet. The overband magnet is used for the removal of any ferrous contamination from the super alloy chips. The shredder and speed of the swan neck conveyor is controlled via. central PLC. The metal chips are fed from the swan neck conveyor onto a Rotajet vibro feed hopper; this ensures the chips are uniformly fed into the Rotajet Swarf washing machine.
Swarf and turnings washing and degreasing:
The Rotajet RJ-PWW2000 is designed to degrease and wash swarf and metal chips, the machine uses a high pressure and high volume heated aqueous detergents. The swarf is transferred through the washing machine using a inclined screw conveyor, as the material is transferred up the screw, the wash detergent is sprayed at high pressure onto the swarf via. 45o knife spray nozzles. The swarf is cleaned by both chemical cleaning action and also the impingement from the force of the spray nozzles. The used cleaning solution is then transferred to a bulk storage vessel for reheating and filtration before being recirculcated for reuse. The degreased swaf then is rinsed in a Rotajet RJ-PWR2000 for rinsing, the RJ-PWR200 works operates in the same way as the RJ-PWR2000, only uses fresh water to remove any of the remaining degreasing solution. The RJ-PWR2000, uses a recirculation rinse and a final fresh water rinse to ensures the swarf is free from grease and cleaning solution.
Once, rinsed the swarf is fed into a RJ-PWD2000 dryer, this machine can be heated via electric or gas. The machine is fitted with a high volume recircualting air system, in which the heated air is blown onto the wet swarf typically between 150-200°C, at these temperatures any moisture is rapidly removed. Once dried the clean, dry swarf is loaded into bulk bags.
Traditionally vapour degreasers were used for degreasing and cleaning swarf and turnings, below is a link to a government website, which outlines the legislation when using this degreasing technology.
Information regarding solvent vapour degreasing plants http://www.hse.gov.uk/pubns/eis47.pdf