DGX now selling Lenhardt & Wagner compressor

[iain/hsm]

Anyway, back to the thing here, is there any data to suggest that the filter life for the L&W is materially worse than other competing compressors in the same size range? Most of the small, portable compressors have a short filter column, which leads to an extremely poor filter life.

Finally back on topic thanks.
And yes I think there are a number of design considerations that L&W didnt employ non of which I will discuss. As for my document evidence on this specific product it was as follows

1. The chemical filter life at 35C of five hours life. The document I referenced was from the workshop manual.
2. The metal filter tower for 300 bar filling needing replacing at 1100 hours. Again from L&W documents. Regarding maximum load cycle questions calculations page 65
3. Ditto for the oil contents and varied changes for oil life from 500 hours back to 250 also from L&W documents
4. Ditto for the pricing discount of 30% also from L&W documents.

As for your question on the chemical used by L&W itself Good point this is also worth investigating,

Molecular sieve 13X or commonly known as zeolite is a pure clear white structure and is brilliant white. The more it is "cut" the darker "Tan" coloured it becomes. Those darker colours show that "Binders" have been used in the process and the supply with the most binders is most evident from zeolite imported from China and the far east.

These binders are carcinogenic so much that even Bauer have warnings printed on the filter cartridge used in the P41 and P61 large filter towers.

In addition to the carcinogenic properties the binders can be up to 30% by volume of the total chemical weight thus in effect making the chemical "charge" at least 30% less efficient when compared to other grade molecular sieve used in say oil free medical hyperbaric chamber compressors, pure air compressors and military missile guidance air compressors all use alternative 100% zeolite (pure white) with no binder, no inert carcinogen material and put another way gain 30% more efficient weight for weight (we have discussed this before).

The filter design itself is also worth investigating including the chemical grain size against the diameter of the cartridge internal diameter and length to evaluate what is called dwell time again something we should discuss in detail on another separate post IMHO

The other considerations are back pressure settings and the filter cartridge "Jet Effect"

As for the compressor chemical filter design there is a little known gem called the 'Kepler Principle" but that is way above the requirements of divers in a public forum IMHO
Everything else is fair game.

 

[C Dub]

So.....Bauer K14?

 

[rjack321]

Anyway, back to the thing here, is there any data to suggest that the filter life for the L&W is materially worse than other competing compressors in the same size range? Most of the small, portable compressors have a short filter column, which leads to an extremely poor filter life.

I dont know the specifics of the L&W but I can say that the little P0 filters which are used on the Bauer junior and my Alkins last about 10 hrs in my summer conditions. Then my RH rapidly goes >20% (within a tankful). In winter (4-8C running conditions) it lasts 20-22 hours. My summer temps are usually around 30C. I use AC and 13x from lawrence factor, its tiny there's no room for monoxycon in there. My installation is quite cool in a large detached garage with the 2 extra fans one on the 3rd stage and one on the 2nd stage head. I run a second 16" tower which I use as a polishing / backup filter. I use a triplex cartridge in that and change it annually, but it never receives gas which hasn't been prefiltered by the primary P0 filter. It never has even been close to used up.

While the RPMs are slow compared to the bauer junior, bearing design on the Alkins 31 that I have is not that great. I do fill banks with it, but try to be modest in my runtimes and do fills on cooler days. The oil sump is tiny and needs frequent changing. Overall its been good to me for the price I paid and considering I have close to 900 hrs with no significant service requirements.

 

[tbone1004]

I will say this you have to be very careful adding water cooling to an air cooled compressor design.

From my position too much cooling at the approach side (or the intake side of the interstage valve) off the cooling coil can cause water condensing inside the valve itself so much so that hydraulic forces can push the head off the compressor or in a process called hydraulic lock.

The correct compressor design allows for a little heat in the heads to avoid water condensing in them and also the heat ensures long valve life. It’s a question of design and balances.

Cooling and condensing water interstage is fine but needs careful consideration and water separation prior to the interstage inlet valves. Although cooling on the after cooler side downstream before the final chemical filter is fine the cooler the better as described above. But I just wanted to raise awareness that its not as easy as you may at first think. And its way off this topic

I have interstage drains on my Rix , but yes, would definitely need some way of getting rid of the condensate that you're generating.

 

[2airishuman]

So.....Bauer K14?

Yeah. The new magnesium model they're coming out with. Two people can lift it.

That's the problem, K14s are great, I've seen them for sale locally, but they are so heavy that I would have to hire a rigger (or a football team) to get one moved.