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Messages - Simtech

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1
Listeroid Engines / Using dessicants to dry fuel
« on: June 16, 2012, 08:44:25 AM »
Through my work I have access to a LOT (5-10 lbs every two months) of silica gel beads.  The beads are fairly large, about 5mm across - they're out of cannisters we use to keep the vent air for the 400 gal hydraulic oil reservoirs dry.  Because of the design of the cannister when the silica gel is used up or contaminated with hydraulic oil fog badly enough they're thrown out. 

I've already figured out how to clean the beads of the hydraulic oil film (a quick bath in acetone) and I know I can regenerate them easy enough, but can I use it to dry out gasoline/diesel/WMO or will the fuels dissolve the silica gel beads and contaminate my fuel.

Thanks

Mods, if this is in the wrong area I apologize.

2
Listeroid Engines / Whats the minimum load a diesel motor should run at?
« on: January 25, 2012, 06:13:14 PM »
How low can you load a listeroid before it begins to cause problems (not getting warm enough, coking up the injectors, etc)?
50%?  25%?  10%?

I've got a possible line on a 12/1 here in my local (ish) area.  Even derating it to 10HP it's putting out ~5000watts at max output.  

At 50% load its about 2500W.

After rectifying and conversion by a (in my case a Midnite Classic 200) charge controller thats:
208A at 12V
104A at 24V
52A at 48V
34A at 72V

At 48V and 72V to a battery bank the charge controller can handle that, but the size of a battery bank to take a 48V/52A or 72V/34A charge as its C/10 rate is rather large (and expensive).

I'm wondering if I reduce the load on the listeroid to match the charging ability of my planned battery bank I'm going to regret it down the road with increased maintenance problems.

I hope that made sense.

3
We're using a system called the Vital 9, its got a bazillion processors on 20"x20" cards feeding five 3-tube RGB projectors, its not quite photorealistic but it looks pretty incredible. 
The program big cheeses have been discussing upgrading to a Vital 10 system, which is PC and gaming video card based, and its less than a 100th the cost...  :o

When flying it on full motion the sim feels absolutely authentic. 

Heh, wandered off topic a bit...

4
I'll never leave the sim world.  Its fun, professionally challenging, I work with a great bunch of guys, and I get to learn something new every day.
I'm getting paid pretty darn good, especially for a Air Force retiree with only an CCAF "underwater basketweaving" (Applied Science - Aeronautics) useless type degree and 1 year into a real BSE degree.

Tell you what though, my first 3 years into this career field blew my hair back in a big way - my learning curve went straight up for 3 years.  Before I was a "computer and networking guy" with tinkering on the side.  Now I'm a "gotta be everything guy".  As of 4 months ago I now also support the maintenance trainers which are basically big chunks of the aircraft in a hanger so now I gotta be a "A&P mechanic" guy too and my learning curve is going straight up again.

I love my job.

5
I started out as a tech for Singer Simulation in the mid 70's, working my way through college. Then helped develop sims for the A-10, F16, TR-1, Advanced Apache while working for various contractors and as a civilian USAF.  What birds are you supporting these days???

I was surprised to read motion bases were there- they were proved unnecessary for training with visual systems in the late 70's, many times over. Our training research lab once had a blow hard General insist that motion was critical, even after several research projects had proved otherwise.  Half way into his flight (F-16 I think) the operators shut down the giant high pressure hydraulic motion system, just leaving the pneumtic G-seat and G-suit simulation systems active. He came out of his simulated mission, still certain in his beliefs, and had no idea that we'd turned it off half way through. Apparently, the irrational, emotional thinking continues!

Bruce M
Concho, AZ
I'm working on the C17 simulators at McChord, there's a pack of 3 full motion sims over here.  Its probably the best job there is, short of working for Mythbusters.  The sheer variety of things I encounter is staggering.

@Tom, We just moved into our house yesterday in Gig Harbor

6
After much thought I'm going with a natural gas backup genny w/ autoswitchover package.  That'll cover 99.5% of the outages.

The listeroid is for my longterm SHTF planning - at least thats my stated reason, mostly though it'll be for the fun tinkering aspect.

7
Listeroid Engines / Re: The best place to get a Listeroid
« on: January 03, 2012, 05:12:09 AM »
The KOELs are the only remaining new 'grandfathered' engines we can offer - only a few available and only in 8/1 configurations. These are of very good quality and will operate just fine straight out of the crate.
Parts kits are less expensive and a good value since most people treat these as complete tear-down projects anyway. They are out of stock except for a few remaining 6/1s.
gary@dieselgen.com
dieselgman

Hey! No touchie! one of those Koels is MINE, mine mine mine mine  ;D 


Just kidding (a little), I do hope there's one still available in a few months for me to order, especially if all that's left is 6/1s in the parts kit.  Definately want a 8/1 with the more robust flywheels.

8
I also posted this on the other forum, thought you might all find this of interest

In my research to find a inexpensive means to clean waste motor oil I found a series of papers written around 1925 on using sodium silicate to clean it.  The gist is that SS of a 1.38 specific gravity is added to WMO at a 1 to 16 ratio.

It'll settle out the particulates to a underlying water layer, evidently with great efficiency and speed.

One paper is here: http://pubs.acs.org/doi/abs/10.1021/ie50181a009

And below is most of the text of another:

Purification of Mineral Oils.

Mineral oils which have been used for lubricating the crank cases of internal combustion engines, for insulating electrical transformers or for oil-immersion switches become contaminated with finely divided carbon which cannot be removed by filtration. The recovery of these oils will, in the future, assume a greater importance than it has in the past.

Van Brunt and Miller found that by agitating mineral oils con-
taining such colloidally dispersed carbon with a relatively concentrated
silicate solution they could cause it to pass completely into the silicate.
As the silicate solution is much heavier than the oil it is a simple matter
to throw the oil upon a body of water and allow the silicate droplets
as they quickly settle out to carry the carbon past the interface into
the aqueous layer, leaving the oil free of suspended matter. It then
remains only to remove the light fractions by heat to obtain an oil ready
for re-use. They worked with oils from the crank case of internal
combustion engines.

Na 2 0, 3.3Si0 2 at various concentrations yielded a sludge which sepa-
rated slowly from the oil at room temperatures, as indicated by Figure
149. It is evident that higher concentrations are more effective. Fol-
lowing this suggestion, Na 2 0, 3.3Si0 2 specific gravity 1.38, was tried in
various amounts. Relations between silicate and oil by volume indicate
that there is nothing gained by using more than 1 : 16 for sedimentation
at ordinary temperatures. Raising the temperature to 80 C. brought the
whole clarification of a 5 cm. layer of oil lying on water within 5-6
minutes and amounts of silicate solution down to 1 per cent were found
to be sufficient for some oils.

Contaminated crank-case oils are not simple suspensions of carbon
in hydrocarbon liquids, and some were found which did not yield to
this treatment, either hy failing to clarify or hy producing a sludge
which was not easily dispersed hy water. All these were brought into
line by adding a mixture of acid manganese resinatc and stearic acid
in the proportion of 1 : 200 and 1 : 1000 respectively, followed by a
1:40 by volume addition of Na 2 0, 3.3Si0 2 , specific gravity 1.38. A
single exception was an excessively dirty sample which required twice
the amount of silicate.

Fig. 149. Reclamation of Crank Case Oil.

Left hand tube Oil poured on water. Center tube After the silicate and
suspended materials have dropped out of the oil and passed into the water layer.
Right Same after settling.

Better dispersion of the sludges and hence easier operation of
mechanical devices was secured by using a still more concentrated sili-
cate, Na 2 0, 1.6Si0 2 , specific gravity 1.67.

The method of agitation found to be most satisfactory is to break
up the silicate into small droplets, just enough to give complete contact,
but not enough to form an emulsion which may occur if too much agita-
tion is used in a relatively clean oil. This can be prevented by adding
carbon black. Air was also found to be essential and must be broken
into fine bubbles during the period of agitation. The authors comment
that this is undoubtedly connected with the fact that not only the more
polar bodies in the oil but also the silicate tend to enter the oil-air
interface. They promise a theoretical discussion of the action of the
silicate solution from the point of view of colloid chemistry.

This should be of great interest. The observation may, however, be
made that the process seems to be essentially a wetting of carbon, col-
loidally dispersed in the oil, by a silicate-soap solution heavy enough
to settle rapidly from the oil and soluble enough to be easily dispersed
in water.

The presence of resin or oleic acid would guarantee the formation
at least of traces of soap and acidic materials ; manganese or other
metallic salts would cause a precipitate in the concentrated silicate
which might, like the carbon black, favor the separation. This, of
course, is not a complete description of the observed phenomena, but
the process affords a striking example of the ability of silicate solutions
to wet surfaces which completely repel water, as well as their part in
suspending carbon after bringing it into water. Soap solutions and
other alkaline salts were tried and found greatly inferior to the silicates.

Other workers have used silicate solutions to wet colloidal carbon
and removed the sludge with the aid of centrifugal apparatus. While
oils of satisfactory quality may thus be produced it is neither so con-
venient nor economical to completely free the sludge from oil as in the Van Brunt method.

9
I read an article on Electrokinetic remediation for contaminated soils and immediately thought of potential use for WMO purification.
http://en.wikipedia.org/wiki/Electrokinetic_remediation

Basically the idea is two conductive plates with a strong DC charge applied and the contaminants move to the plates to be removed. 

I am NOT in any way a chemist/chemical engineer nor do I play one on TV so I have no idea if this would work, but has anybody here ever tried it?  It sounds like a fun experiment to do.

I'd do it myself but I'm in the middle of a move from Tacoma to the outskirts of Gig Harbor and I won't have a workshop set up for months yet.

10
Listeroid Engines / Re: Adhesives and sealants
« on: December 01, 2011, 09:13:45 PM »
Found the perfect sealant:  MAS Flexbond 5000 sold at West Marine or other marine stores.  Its a polyurethane based hybrid, unfortunately it's pretty spendy at $25.00 for a 9.5oz bottle

Service temp is -40F to over 212F with short term surges to 350F.

From all accounts its incredibly strong and will stick anything to anything permanently and adheres to metal particularly well.  One guy described it as "welding out of a plastic tube".

11
Listeroid Engines / Re: Adhesives and sealants
« on: December 01, 2011, 01:56:16 AM »
@Dieselman:
The phase change material is paraffin wax with a ~130F melting point, it'll be in 2-5/8" copper DWV pipe tubes in a horizontal crosshatch grid starting 2/3rds of the way up the tank.  A lot of copper and a lot of wax.  At least it'll displace some of the 75/25 water/proplene glycol mix I'll be using as my working fluid.

I've used wax as a storage medium before in my solar hot water experiments, its amazing how much heat it stores - and it moderates temperature swings, especially during the thermal discharge cycle where a steady ~130F is maintained until its re-solidified.  Its also extremely stable and can undergo thousands of cycles without breaking down.
Gotta be careful filling the tubes though, because wax expands so much when melted it the tubes have to be filled hot with melted wax (leaving 1.5" unfilled at the top) and the cap soldered on immediately.  Its also real easy to screw up a solder joint if wax gets on it.  Its REAL easy to overfill (tube not hot enough and solidifiies the wax during the fillling process) and have a split pipe during its next thermal charge cycle.

@Fabricator
A tranny gasket is only at most a few mm's thick, with supporting metal nearly encapsulating it.  I'm expecting gaps of up to a 1/8".  I just dont think silicon is strong enough, or adheres well enough.  The tank is going to be tall but fairly narrow, its intended to stagnate the water so the incoming heat doesnt mix with the cooler strata.

I think I might just go ahead and spend the money on the flexible epoxy.

12
Listeroid Engines / Re: Adhesives and sealants
« on: December 01, 2011, 12:36:45 AM »
I'm envisioning a compression fit:  Two threaded flanged connections on a threaded piece of pipe that meet in the middle and clamp down to the tank wall.  However I see potential gaps where the flat flanges meet a rounded tank wall.

I'm sure there will be vibration conducted by the radiator hoses, thus the need for a flexible but extremely durable sealant.  From what I understand JB weld and/or other epoxies will eventually crack from the vibration.

So far I've got several loops in/out of the tank:

Engine cooling loop
Exhaust gas heat recovery loop
Excess heat removal loop
Domestic heating loop
Domestic hot water loop

Because they all depend on thermosyphon flows (except for the domestic heating loop) placement of the inside tank pipe ends is critical, thus I cant "re-use" a penetration and have two loops share one hole.

I'm also using a phase change material inside the tank for thermal storage, which complicates the problem even more.  When I get the drawings done I'll post them for comment in a separate thread.

Dave

13
Listeroid Engines / Adhesives and sealants
« on: November 30, 2011, 06:33:49 PM »
I've been designing the cogeneration domestic hot water system and I've realized I need a flexible sealant for the many tank penetrations thats capable of handling water at or near boiling.

The coolant coming from the engine thermostat will be @ ~195 degrees not to mention the heat derived from the exhaust.

Silicone isnt a sealant, its a gasket material:  There's no strength to it at all, however it has excellent chemical and temp resistance.  I dislike silicone immensely - I'd never use it in a permanent installation.

The only two common sealants that I know of are 3M polysulfide and 3M 5200 (polyurethane), both of which I've used on my boats.  (BTW, the boat-life polysulfide is crap - dont ever use it)  Both take up to a week to cure.  Both have excellent adhesion, 5200 is incredibly strong.

3M Polysulfide has a service temp of 180F
3M 5200 has a service temp of 190F

There are some exotic epoxies that I've used professionally like Duralco, but they're fairly expensive.  Duralco has a service temp of 450F and is still very strong yet flexible enough to tie it into a knot.

So, what other commonly available sealants are available that can withstand boiling water?

Thanks

14
Listeroid Engines / Re: KOEL 8/1 completed engines available
« on: November 28, 2011, 06:51:57 AM »
Dang, with only five available they'll be gone by the time I'm ready to purchase one (about 4 months)

Heh, unless you're willing to do a layaway plan....

15
Listeroid Engines / Re: KOEL 8/1 completed engines available
« on: November 23, 2011, 10:17:26 PM »
How many hours (if any) are there on these engines?

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