[k_v]

Hey guys, we've been tasked with providing solutions for reducing coolant consumption by our client using automation. One of those is a system to reclaim the coolant dripped off of the chips from a Chip Trolley in a CNC Machine. Around 15-20 Litres of coolant+water emulsion is wasted everyday, even more on certain machines. And this data is for one machine. Considering the total number of machines in our client's Machine Shop, we believe this would go some way in solving coolant consumption issues for them.

So basically we have designed a Venturi Injector. This was designed by taking some inspiration from existing Venturi designs from the internet. I am in no way an expert on Fluid Mechanics or CFD. The motive liquid in the injector is the Coolant pumped by the Coolant Pump (The unit is connected to the discharge of the pump by a Tee). In the suction port, we have connected a 6mm OD PU Tube and at the other end of the tube is a Suction Block with filters. This block is to be placed on the Chip Trolley. Please see attached file for the drawings.

So in this lockdown, since it is difficult to visit clients, we took trials with our own small pump used for transferring water in our office. We connected the flexible hose from the discharge of the pump into the inlet of the Venturi with a Hose Nipple & Clamp. Our small pump is a 0.5 HP domestic pump that discharges approx. 35 LPM. We placed the Suction Cup into a box with some amount of water.

What we saw was the venturi worked to some extent, as in it sucked the water through the cup, but it would stop sucking liquid after a point. And this happened in multiple trials. We even changed the 6mm OD tube into a 8mm OD tube, but the result was the same. We need the system to reclaim all the water (or coolant). Also we noticed that the outlet of water from the venturi would fluctuate i.e the flow-rate of water kept varying as the suction was taking place. Maybe the flow-rate from the pump is not constant, I need to verify that.

Yes I know I would probably need to take more trials with a bigger pump, but I was wondering if you guys could let me know if I am going wrong anywhere and if there were some immediate changes I can make to achieve this goal. I have filmed one of the trials which can be found on this link - https://photos.app.goo.gl/LLWaS6m3QR4aEqPp6
Maybe that might help you'll get a better idea of what I am doing.

Any advice would be great. Thanks.