O'Green Hydraulic Compressor

[CraziFuzzy]

I have discovered that the ecofueler guys have seemingly developed a hydraulic compressor for home CNG use, and will be making it available for owners of their ever so ugly CNG Roadster. This compressor is manufactured by O'Green Compressors, but o'green does not have any information on the home-sized unit on their web site. For those not compressor saavy, a hydraulic compressor actually seems to make the most sense for CNG apps (we used a very similar compressor for hydrogen fueling at the plant i worked at). Instead of a high speed electric motor spinning the crank on small low-capacity cylinders, thereby making for a lot of noise, a hydraulic compressor uses a simple hydraulic oil pump, (much more steady, and controllable noise levels) and uses that hydraulic pressure to push a very slow, much larger CNG cylinder. Parts manufacture is a lot cheaper, as components are much larger. Tollerances would be easier to. Safety would be theoretically improved, as the gas side could be completely remote from the electric side (only connected by the hydraulic lines).

I actually feel bad that I had planned on developing a similar product, based solely on my dislike for the fuelmaker designs. Missed my patent on that one i suppose.. Any opinions/buzz on this compressor?

[freedml]

Re: O'Green Hydraulic Compressor

If the compressor is on the same production schedule as the motorcycle, don't hold your breath! Makes the Phill roll-out look lightning-like.

The big problem with this type of compressor is that you're introducing oil into the equation, which will kill your injectors and perhaps the regulators, too. Fuelmaker may be noisy, but it is oilless.

[TheBundo]

Re: O'Green Hydraulic Compressor

Shouldn't need oil in the compression area, use ceramics or something

[CraziFuzzy]

Re: O'Green Hydraulic Compressor

If the compressor is on the same production schedule as the motorcycle, don't hold your breath! Makes the Phill roll-out look lightning-like.

The big problem with this type of compressor is that you're introducing oil into the equation, which will kill your injectors and perhaps the regulators, too. Fuelmaker may be noisy, but it is oilless.

I don't believe the oil comes into contact with the gas at all. in most hydraulic compressors, the oil is in a seperate cylinder, providing the force on the gas compression cylinder. If you know more about this particular compressor, and that it is NOT in fact a standard hydraulicly driven reciprocating compressor, then i stand corrected.

[Curtis]

Re: O'Green Hydraulic Compressor

When I spoke to them last they claimed a 25 yr service life on the compressor with virtually no service. The unit turned at 25rpm. They would only include it with the trike and they wanted $100k for a compressor that would handle my station.

[CanAm]

Re: O'Green Hydraulic Compressor

There are other companies that do hydraulic compressor of this type. I believe CompAir do them.

[cowboy]

Re: O'Green Hydraulic Compressor

why whould any one want a oiless compresser whould you drive your car without oil? that is why they put rings on the pistons to keep the oil in the crankcase if oil gets in your gas something is wrong I use a davey compresser 15 scfm to fill my pick up it is twisted by a 2 cylinder hatz diesel it uses about 1 gallon to fill my pu to go 900 miles for a cost of2.25 cents per mile for compressing and I use well head gas which is free road tax is 18.90 add that to 4.00 doller diesel is 22.90 to go 900 miles not bad I dont worry about my compesser as it is up to just over 4000 hours and it calls for rebuild at 25000 hr by that time I will be in the ground with dirt in my face I do not understand how one can justify a phil unit as I use 30 to 40 gge a day it cant do the job and no oil they wearout and cost to much and the phil fokes dont want you to use well head gas I think big oil and big goverment do not want any change they just let us play as it is a joke to have 6 or 7 gge tanks and it is doable now to go many miles on cng with bigger tanks they just what us to go away as for carb and epa any cng motor will burn cleaner than gas or diesel just look at the ex pipe on a cng motor I even changed my fork lift to cng as it is cleaner than propane that it came with no more headace from fumes must be clean

[ziba]

Re: O'Green Hydraulic Compressor

I am looking for information on how these hydraulic drive compressors work.
and also which companies have designed and used these compressors for CNG.

[cngmike]

Re: O'Green Hydraulic Compressor

Every thing is a trade off. Oil less and oil free compressors have a shorter time for rebuild. A Sulzar or Arial compressor have a 10,000 hour top end rebuild time. Corken has a 5,000 hr. top end rebuild time. A fuelmaker 4,000 total rebuild time. With the first 3 you have to be fanatical about oil carry over, most station operators are not. The Fuelmaker is very cheap up front and on initial maintenance but cost you down the road. It is also the quietest package on the market. The one trap all packagers fall into is the marketing guys pushing the RPM for more through put. Thus driving up maintenance and shortening rebuild times. To my knowledge there has only one commercially operated station with a hydraulic compressor as the driver. I have no idea how it performed. The station is closed the operator was no where near dedicated.

[Amfuel]

Re: O'Green Hydraulic Compressor

The home sized hydraulic compressor would not be able to compress any faster than the Phill if certified to be mounted inside the garage. The NFPA regulates the output to 50scf/hr. Outdoor systems can operate at higher rates but I haven't looked up the max for residential. I suspect the 120scf/hr though. That would put it in line with a FMQ-2. These things have all been thought out in advance of manufacture.

I studied the hydraulic system concept a while back and it looks like a great concept. The hydraulic pressure matches the gas pressure so theoretically there is no blow by. There are large systems out there. Big comes with a big price as usual for any system.

What is nice about the FM Q series systems is the modular design that allows adding volume and/or storage so the system can be expanded as needed, when needed and not having to replace a compressor with a larger one. The Q-8 uses 4 compressors in a module so if one compressor fails the rest keep operating and the system is not dead in the water like other brands.

Noise? The Phill outputs 45db, about as much noise as a window a/c unit. The Q-2 is at 65 db still pretty darn quiet. The Q-8 is noisy and your neighbors would not like you anymore.

[CraziFuzzy]

Re: O'Green Hydraulic Compressor

Some of the advantages of a hydraulic compression system is the leverage of off-the-shelf hydraulic components. You can save a significant amount of money on a medium sized system due simply to the fact that most the components are already mass produced. The specialized machining required to manufacture a hydraulic compression system is FAR less than that required to manufacture a reciprocating compressor block, and the hydraulic system and all electronics can be remote from the gas, thereby limiting the requirements for expensive intrinsically safe components. Using side ports to operate the hydraulic supply valves can actually result in NO electronics required at the site.
Simplified drawing of a hydraulic compressor. Discharge pressure is controlled completely by peak hydraulic supply pressure, and the ratio of hydraulic to gas piston diameters. Flowrate of the gas is actually controlled by flowrate/capacity of the hydraulic system.

[Amfuel]

Re: O'Green Hydraulic Compressor

Thanks for the picture. From my reading I was under the impression that the design was a single cylinder with gas on one side of the piston and oil pressure on the other side. Gas in/out valves at the top and hydraulic push/pull at the other end. Hmmm. I think I like my impression better as there is only the one piston ring/seal and equal pressure on both sides.

Just an opinion of course. If there are any inventors out there you can send me a really, really nice gift after you get rich.

[CraziFuzzy]

Re: O'Green Hydraulic Compressor

The O'Green compressor is as you discuss, a single cylinder with a floating piston. the picture I posted was of a more conventional compressor system... The advantage of the split system is the fact that the hydraulic pressure does not have to be the same as the gas pressure. The advantage of the single cylinder is that the leakage by the piston is minimized, as the pressure is near the same at all times.

O'green's larger compression systems (the non home-sized units) are 3 stage. First stage is seperated, as shown here, and 2nd and 3rd are single cylinder style.

For an example of the split system, check http://www.hydropac.com

[cowboy]

Re: O'Green Hydraulic Compressor

lets build one of these things without the pump mount it in the trunk and power it from the power steering pump than all one would need to refuel would be a hose and a friendly gas meter just hook the hose up blead air fip deverter valve just let it idle soon the car would be full no high pressure to handle or just hook up a hydraulic pump at home and plug wet line in at same time as low pressure ng line and one could put a ball valve on the meter at say moms house now you would have return fuel

[Amfuel]

Re: O'Green Hydraulic Compressor

Hahaha, Let me know when your ready, I'll plug my ears.