I. Precision Water Chiller for High-speed Motorized Spindle
1. Model Selection
(1) Water temperature: about 25℃
(2) Water pressure: about 0.2MPa
(3) Heating power calculation of motorized spindle
P (Heat)= P (Motor)· η
P (Heat) ———Spindle heating value (kW)
P (Motor)———Spindle driving motor power (kW)
η———Spindle heat loss efficiency
When calculating heat loss efficiency, η=30% for a high-speed motorized spindle (general domestic motorized spindle: η=30%; Taiwan motorized spindle: η=25%; motorized spindle in German, Switzerland and Japan: η=20%).
MCW-35C has a cooling capacity of 3.8 kW under water temperature 25℃ and ambient temperature 30℃, which is greater than spindle heating power, making it a perfect choice. When water supply pressure stands at 0.2MPa, flow will be 23L/min.
II. Water chiller dedicated for low-speed EDM cutting machines
1. Model Selection
(1) Heating power is calculated on the basis of running power
P (Heat) = η·P Powering on
P (Heat)———Heating value (kW)
P (Powering on)———Running power (kW)
η――Heat loss efficiency
Low-speed EDM cutting machine: η≈20%
(2) Heating power can be calculated based on rate of water temperature rise
P熱= CP ·m·ΔT/t
P (Heat)———Heating power (KW)
1 kW =860 kcal/h
1 kcal/h =1.16x10-3 KW
CP ———Specific heat at constant pressure (KJ/Kg·℃)
Specific heat at constant pressure (Water) 4.18 KJ/Kg·℃
m——Total water tank volume (kg)
ΔT——Temperature rise per unit time (℃)
T(t)——Time (S)
e.g. For a low-speed EDM cutting machine with effective water volume standing at 400kg, water temperature rises from 25℃ to 29℃ after working normally for 40 min. You can select a model as follows:
P(Heat)= 4.18×400×(29-25)/(40×60)=2.79 kW
Cooling capacity of precision water chiller should be 20% greater than the calorific value. MCW-35A or MCW-35B will be a perfect choice.
2. Schematic Diagram
Notes:
1. When connecting precision water chiller and the machine tool, you are suggested to install a filter on the water pipeline, as shown in the above figure.
2. Precision water chiller shall be used in a well-ventilated place without dust and corrosive gas. Do not place any sundries around the chiller.