User Tools

Site Tools


projects:air-for-workshops

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revisionPrevious revision
Next revision
Previous revision
projects:air-for-workshops [2011/08/05 15:29] – [The solution] spineryprojects:air-for-workshops [2014/04/02 06:57] (current) – external edit 127.0.0.1
Line 1: Line 1:
-====== Summary of the problem ====== +Disregard that, must do more research
- +
-I have limited experience with pneumatics, so it would be pretty nice if someone could read this and provide some criticism. If the opinion is positive, I will build this system, and publish the results, performance and issues that arise with it. +
- +
-I was researching the possibility of most cost-effective, expandable and flexible application of pressurized air in a workshop oriented around multiple tasks, such as a Hackerspace. I want to use this for: +
- +
--pneumatic tool operation (better than electric - lighter, more powerful, less moving elements, easier to provide air than electricity) +
- +
--sanding (most universal abrasive processing method) +
- +
--vacuum generation (electronics, but also moulding) +
- +
--injection (moulding, oiling) +
- +
--spray-coating +
- +
--hi-quality spray painting +
- +
--refrigeration through vortex tube +
- +
-I want this to be as simple as possible, with fewest elements, and ability to power the setup through different means (in case there is no electricity available) +
- +
-Generation of huge volumes of air require a lot of power, and use of screw compressors. They are good for continuous work, and the variable rotation speed compressors are prohibitively costly. Additionally, some screw compressors have only one screw powered, the other being powered by friction from the first one, increasing wear. I can;t be bothered to research which are which. For on/off work, we should use a piston compressor. It is also the easiest to service, and most machine shops can manufacture parts (even more durable than the originals). +
- +
-I decided to go a different path - contain huge volumes of highly compressed air, generated by underloaded hi-pressure compressor. +
- +
-====== The solution ====== +
- +
-The solution fits within 16000 PLN net sum total. +
- +
-Compressor: Atlas Copco LT 3-30 or 4-30 (10000-12000 PLN, 2000 PLN net price difference, higher model has doubled FAD (Free Air Delivery - the amount of air the compressor can generate))(brochure: http://www.trident.on.ca/PDF/AtlasCopco/L_Series.pdf) +
- +
-Why: It's an industrial compressor, fit for continuous work. It should last forever in our application, when it works under maximum loads only on certain occasions (sanding, refrigeration, vacuum). It generates 30 bars of pressure, and the FAD is 0.17 and 0.29 square metres per minute @30bar. It can be powered with a variety of means, including belt drive. +
- +
- +
-Tank: http://www.komnino.com.pl/of1.asp 300 litre 35 bar tank, vertical, 140 Kg of weight, ø612 x 1530, 3700 PLN. It gets filled by the compressor to 30 bar in 2 minutes (LT3), or 1 minute(LT4). It is lighter than 25 bar tank, I assume a different alloy/steel type is used. +
- +
-Why: The tank is relatively small (compared to the volume of air it can house), and is relatively mobile - two people (or a single stron person) can load it onto a vehicle in a horizontal position by simply tipping it. It is not the best money/capacity ratio, which is reached around 400-700 litres, but these are cumbersome. What is really impressive is the amount of air it can contain in its volume. Under 6-8 bar, the pressure for pneumatic power tools, it can sustain a continuous operation at 220L/min (180mm angle grinder, full power) for about four minutes, without the necessity to turn on the compressor +
- +
-Benefits: +
--Dry air. The pressure in the installation is suited for power tools and other general tasks, therefore it's lower than the pressure in the tank. Because the pressure is reduced, the water is not gathering in the pneumatic plumbing/installation, because air does not contain enough water for condensation. The tank serves the purpose of a desiccant, without moving parts. +
--No air pulsation +
--If inlet of air is at the bottom of the tank, the water present in the tank will act as a filter. +
--Heavier particles (oil) will have time to settle down into the water during the time the tank is unused. +
- +
-Additional elements: Tank exit air warming. +
-The working air that exits onto your tools is heated up with heat from compression, that is normally wasted, therefore it does not cool to below atomspheric temperature during decompression, increasing efficiency of the whole system. Heat recuperation is used in some desiccant devices, so it's nothing new. An insulated oil container can be used as a way to hold heat when the compressor is not used simultaneously with working air. +
- +
-The aim of this setup should allow for a very good performance in short tasks, and relatively cheap expandability if prolonged use is required (buying additional tanks). +
- +
-Additionally, it is breakdown-proof. If your main compressor breaks down, and you cannot afford to repair it, but still need to use compressed air, you can still run on the capacity of the tank(s) with a borrowed or used compressor. We're basically focusing on accumulation of air rather than generating huge amounts of it quickly, on-demand. +
- +
-Opinions please.+
projects/air-for-workshops.1312558150.txt.gz · Last modified: 2014/04/02 06:57 (external edit)

Donate Powered by PHP Valid HTML5 Valid CSS Driven by DokuWiki