This paper will give you understanding of how your CNC Plasma Water Table GreenCut® Coolant should operate with the proposed Coolant Circulation System.
First off: Please study the Frequently Asked Questions (FAQ) for CNC Plasma Arc Cutting Tables carefully, found here. The website explains the product in detail, and of course I am available as back-up for technical questions. The picture/video you see on the website, drinking GreenCut Plasma is the undersigned, to show its safety. Please note that it’s safe to breathe as well, see SDS.
I am basing your CNC Plasma Cutting Table Coolant capacity of a 100 US Gal. size: 9′ x 4.5′ x 0.333′ = 13.5 cu. ft. x 7.5 US Gal = 100 US Gallons. At a dilution ratio of 20:1 you will need 5 gal. (one pail) of GreenCut Plasma Cutting Fluid as an initial charge for the table described, plus extra for topping up the GreenCut Plasma as you operate the Plasma Table. Your pH should be 9. This proposal will work for Tables from 50 US Gal. to 400 US Gal, beyond which the pump size should be enlarged. Please contact me for pump sizing, etc. for larger systems.
Yes, you need to circulate the mixed Water/GreenCut coolant, see GreenCut Data Sheet and GreenCut Disposal Sheet Study for details on why and how. Especially so since you are going to circulate and filter the coolant system to eliminate waste particles as well as making the coolant last longer with 5-micron filtration and topping up with the GreenCut Plasma as required per pH readings (always shoot for a pH of 9 or higher, check it weekly). Additionally, you will need more GreenCut Plasma for keeping the table at a pH of 9 (FAQ #14). Suggest you lay in an extra pail of GreenCut Plasma for a new start-up of the Table.
Note: If it is a used Plasma table you will have to drain and discard what is in the tank now, and additionally you will have to scrape the rust and crud out of the Plasma table and start afresh.
Now, as to the circulation equipment required for your plasma table:
Please study the enclosed sketch of a typical plasma table Circulation System, see also FAQ #10 – 12 which includes a triple compartment setup for a large plasma table/tank. You will note that the pump suction is taken off the table near the top of the liquid, to prevent crud from damaging the pump; while the pump discharge(s) is pushed low into the tank to push the existing crud out of the way.
Your pump requirement is 1/25 HP (see below suggested pump detail), providing a circulation frequency up to 4 per day at 0.5 gpm per 100-gallon Plasma table tank. (For a 400 US Gal. tank your circulation frequency would drop to 2 per day). We suggest working with 1/2″ piping for your setup; it’s safer and may outlast the table. For total bath circulation then: you will have 1 only 1/2″ suction with 1/2″ piping and 2 only 1/2″ discharges with one 1/2″ header, pump and filter details below. The below sketch shows how your table should pipe up. We suggest 1/2″ plug valves and 1/2″ sch. 40 steel pipe and fittings, all screwed. 1/2″ piping is fine for table sizes of 50 to 400 US Gallons.
If the Plasma Table is used intermittently, start the circulation pump for about 2 hours every three days or so, to prevent mold formation etc. caused by stagnant coolant. This will assure inter-molecular contact between GreenCut Coolant and bacteria which may try to form as a mold on the coolant surface under moist and warm circumstances.
I assume the CNC Plasma Arc table contains an air bladder for coolant lift right against the plate being cut, or by burying it in the coolant in the case of cutting gauge plate. It is very important for safety and cutting finish reasons to eliminate air gaps between cut plate and coolant, i.e. eliminating any smoke from plasma cutting which should not be breathed. Remember that you are cutting under very hot conditions with the Plasma torch: from 7,000°F to 25,000°F. Under these temperature conditions you are cutting/melting the metal being cut. Plus, you are also vaporizing the metal particles into molecular size which will be in the smoke, that you for sure won’t want to breathe.
If you have further questions, please contact me. I’m here to assist you.
Chief Chemical Engineer
LubeCorp Manufacturing Inc.
Tel: (403) 250-8448
Tel: (800) 661-6100
GreenCut® Plasma Coolant Tank
100 to 400 US gal. Capacity
The proposed Pump: Grundfos 59896341 Brute Three Speed, 1/25 horsepower has a Flow Range: 0-17 GPM, with a Head Range: 0-19.5 Feet.
The proposed Filter: Pentek 150237 Big Blue Filter Housing along with Pentek DGD‐5005 (10″ x 4 1/2″) spun polypropylene filter cartridge is graduated to filter the coolant from 50‐micron down to 5 micron in a graduated filter core, so that the outside gets loaded with coarse material waste prior to penetrating further in the filter core to clean the coolant down to 5 microns in one step.