Refrigerated Coolant Chilling systems

Modern Manufacturing technology uses sophisticated machines, designed to work at high spindle speeds, high feeds depth of cuts ensuring precision of highest quality. As  a result of this there is a huge amount of heat generated at the work piece / tool interface due to friction. This heat will reduce the tool life and also affects the quality of work. Hence it becomes imperative to reduce the heat generated at the work piece, tool interface. This is accomplished by means of a fluid known as coolant.

Function of coolant in machining / grinding operation.

1. It cools the tool by absorbing the heat & hence enhances tool life.
2. It provides lubrication to the tool & work piece interface
3. It protects the machined surface from corrosion
4. Reduce the cutting forces & hence the Power Consumption

Importance of Coolant Chiller:

As the coolant comes in contact continuously with the tool & work piece it absorbs heat and hence the temperature of the coolant rises. With the rise in coolant temperature its heat absorbing capability diminishes and hence it further cannot cool the tool. Hence it becomes vital to cool the coolant and maintain its temperature and other physical & chemical properties within prescribed limits. This is accomplished by means of a Coolant chiller. 
A Coolant chiller performs this function by exchanging the heat gained by the coolant with a refrigerant which is at lower temperature in a suitable heat exchanger.

Brief Description

Werner Finley made chillers typically come as complete packaged closed loop systems including all the components such as compressor, condenser, condenser fan, evaporator, evaporator fan, expansion valve, accumulator, the necessary refrigeration controls & accessories.
In any application the Coolant Chiller works in tandem with a Filtration system
to deliver clean & cool coolant at constant temperature to the machining process.

Classification

1. Based on the type of Heat Exchanger (Evaporator)
   • Immersion Type
   • Shell & Tube Type
   • Plate Heat Exchanger
2. Based on the type of Refrigerant
   • R22
   • R134a      (Eco – Friendly)
   • R407C     ( Eco – Friendly)

Working Principle
A Coolant chiller works like any other chiller. The coolant after coming out of contact with the Tool/Work piece interface is generally passed to a filtration system. The filtration system cleans the coolant by segregating the fine dust, chips & foreign particles from the coolant. This filtered coolant is allowed to enter the chiller where the coolant exchanges heat in the evaporator with the refrigerant and hence becomes cool. This cool coolant is pumped to the process & the cycle repeats

Typical Coolant Chiller application in tandem with a Filtration System