Abstract:
Coolants are used to negate or minimize the thermal stresses developed during any machining process. However, some environmental and health issues are associated with traditional coolant. Documented health issues include Cancer, Dermatitis, Respiratory irritation, Asthma and Hypersensitivity Pneumonitis. In this experimental study, the effect of Ranque-Hilsch vortex-tube generated cold air/hot air is observed in a machining process as a replacement for traditional liquid coolant. The optimum dimension for maximum energy separation is obtained by trial method using computational fluid dynamics (CFD). For available compressed air of 6-8 bar, the optimum dimensions and geometry of the vortex-tube are: length (L) 300 mm, tube diameter (D) 20mm, cold outlet diameter (dc) 6mm, inlet nozzle diameter (din) 5mm, angle of control valve (φ) 50
degree. Temperatures in the hot outlet and cold outlet are Thot= 33℃ and Tcold = 14℃ are observed
in the CFD model. Optimized vortex-tube outputs are then used as input parameters in AdvantEdge 3D software for studying post-machining characteristics of the workpiece. The chief parameters representing the machining quality are stress developed in the tool and workpiece and chip thickness. Machining quality with vortex-tube supplied air, conventional coolant and no coolant are then compared.
