2014-08-19 10:10:00
#1
Cooling water flow rate required for injection mould
Is there any formula or thumb rule for calculating the cooling water flow rate required for a particular injection mould? Pls advise
2014-08-19 14:43:00
Top #2
Hello
as a rule of thumb you should keep your flow turbulent, for that you need to calculate the Reynolds number (http://en.wikipedia.org/wiki/Reynolds_number) and make sure it is well above 10,000
more rigorouly you should treat your mold as a heat exchanger, it is usually a quite simple heat exchanger with text book solutions. any chemical or mechanical engineer should be able to give you a good solution easily.
for very precise requirements use a consultant and run CFD analyses.
as a rule of thumb you should keep your flow turbulent, for that you need to calculate the Reynolds number (http://en.wikipedia.org/wiki/Reynolds_number) and make sure it is well above 10,000
more rigorouly you should treat your mold as a heat exchanger, it is usually a quite simple heat exchanger with text book solutions. any chemical or mechanical engineer should be able to give you a good solution easily.
for very precise requirements use a consultant and run CFD analyses.
2014-08-19 16:47:00
Top #3
Is very important to get turbulent flow in cooling lines. Reynolds Number is 3600XGPM / Cooling line diam. * KV, where KV is kinetic viscosity, but an approach normally used on the field is: Water Flow required in GPM=3.5 * Internal diam. of water line.
With this approach if cooling line has an internal diam. of 1/2".
Water Flow in GPM=3.5 * 0.500
Water Flow in GPM= 1.75 to get turbulent flow.
Thank you
Francisco Gallegos
Carling Technologies
With this approach if cooling line has an internal diam. of 1/2".
Water Flow in GPM=3.5 * 0.500
Water Flow in GPM= 1.75 to get turbulent flow.
Thank you
Francisco Gallegos
Carling Technologies
2014-08-19 19:29:00
Top #4
To be practical you need a inlet and outlet device to meassure pressure drop and temperature change. For pressure less than 3 bars and for temperature no more than 2 degrades celsius. narcisolopez at moldeofacil
2014-08-19 21:49:00
Top #5
Narciso I agree have a flow meter from press to press and verify tempeture including flow, we just installed new chillers and looking for a proven way in how the chiller helped I have done this before, but looking for a better way or scientific how its now called.
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2022-07-15 17:05:00
Top #6
Manpreet, Every tool and it's Cooling Line design is different. You can get lost in the numbers trying to calculate what the efficiency of your design is and how the variables of water temperature and flow rates can lead you down a dead end road. Without getting into detail of Mold Material, Cooling Line Size and Design, Water Input Temperature and other variables, I would suggest that you understand the Water Flow Rate and be able to adjust it to meet the requirement of your molding process. It has been my experience that the people looking to solve cooling by calculations usually come up with answers by Reverse Engineering----After collection of data on a running tool. A good tool designer will pay attention to the most cooling that can be routed around all of the Part geometry in a tool-----this is typically in the final stages of tool design and most often IS NOT the most effective cooling design. Also, in many Multi-Cavity tools, the Water Line routes may be designed in series----thus a rise in water temperature from cavity to cavity----and an unbalanced process. Many things to consider.
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