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Old 2010-03-31, 7:52pm
metalbone metalbone is offline
Kobuki & DIY Homefill Sys
 
Join Date: Apr 30, 2009
Location: socal
Posts: 220
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Quote:
Originally Posted by kbinkster View Post
The Hurricane is, from my understanding, the tweaked guts of medical concentrator(s) put into a new case. I could be completely wrong about this, but that is what I have been told and that is what it looks like when looking at pictures of it with the case off.

When you push too much air through the sieves, the sieve material burns out and the compressor burns out. When you run a certain amount of electronic components on wiring meant to carry only a fraction of that load, your wiring is going to fail (fire hazard). There is a reason that machines are made the way they are by their original manufacturers.

When you want to get more flow at higher pressures, you have to use a larger volume of sieve material. If you pass a larger than intended volume of feed air, or that feed air is pushed through at a higher than intended pressure (and by intended, I mean what was intended by the original manufacturer of the base machine/component) through a normal canister, you will damage the sieve material (resulting in poor purity and dusting - and you do not want sieve dust in your torch valves, it is like ground glass).

There is a higher grade sieve material available, but it is very, very costly (outrageously expensive) and is meant to be used in smaller canisters in smaller machines to get more flow out of a smaller canister (not higher pressure). But, nonetheless, if this higher grade sieve is poured into a regular-sized system meant for the regular sieve, but is simply overrun (a larger than intended volume of feed air is put through or you push the feed air through at a higher than intended pressure) and if the sieve holds up, you will still burn out the compressor.

If you correct this problem by replacing the compressor with a higher grade compressor capable of handling that load, then the price of the machine goes up even more and you will still have the problem with the wiring. If you correct the wiring, then you will then have added on even more to the price of the machine. And then, there is the matter of all the other components of the system and whether or not they can handle the increased work load (like valves and hoses and whatnot). Oh, and then there is the cost of having a special cabinet built to house it all which adds to the cost.

To build a system like this, and build it the right way, is not cheap.

Oh, and there is also the issue of whether or not a system like that can be run for very long at a low flow (small flame). When you run a small flame, you basically backpressure the machine. When the machine is backpressured, the air is held in the sieve canisters longer, giving better separation, and the result is a temporary increase in purity. The problem, though, is that this is hard on the sieve. When you increase the throughput, the problem is exaggerated. So, on these larger machines, there is effectively a minimum flow rate. If you are not made aware of this, and you work with mostly a small flame using a large flame occasionally, you could be damaging your machine.

There are still going to be people flocking to buy these things, knowing that they could be trouble. They're willing to take the time to fix them when they break down and they're willing to put up with the hassle because the upfront cost is low enough to make them attractive (especially when compared to the high cost of a new generator system, when that was all that was available). What people don't usually account for is the value of their time and the value of their wellbeing. If the time spent fiddling with the machine were spent busting out prodo, how much money would that be? If the machine is out of commission waiting to be repaired, how much does that cost (in lost work or tanked oxygen cost while waiting, if available)? If the aggravation did not stifle your creativity or put you in a troubled mood, how much more productive would you have been? Some of that is really hard to measure, but some of it is pretty straight forward. Of course, there are people who enjoy tinkering. If they are using this as a hobby, then the breakdowns are not an inconvenience and they don't mind losing production.

I don't think that anyone knowing all that and still buying one is lacking or anything for going that route (heck, you have to be smart to fix them when they break down). It is a business decision and you have to decide what is best for you at the time. You can only do what you can do. But, what I do want everyone to know is that new and properly reconditioned, non-tweaked used machines do not give this much trouble. I hope that people reading about these Hurricanes and the other UO/EO machines don't think that all machines are like that. They're not. And now that there is another affordable option available for high pressure output, I hope they really understand that.
This is good info, thanks!
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