Propane fired Vitodens....(revisited)......hb

[Deleted User]

I have seen this on a few munchkins i have installed. I thought that it was burnt up pvc from not getting all the burs off the pipe before instalation but we make sure to cut pipe with a chop saw and debur everthing. Now that it is happening to other wallies maybe it is a gas byproduct.

<A HREF="http://www.heatinghelp.com/getListed.cfm?id=396&Step=30">To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"</A>

heatboy

It's all in the fuel.

After dismantling all of my Vitodens for service, I have found that the propane fired ones are the ones with coffee grounds in them. My NG ones are groundless, since the quality of NG here in my area is very good. I saw a chart somewhere (Viessmann, I believe) that rates the quality of natural gas in the USA. I don't remember who has the best, but Colorado has the absolute worst in the country (by far). Sorry ME, but you undoubtedly know this already.

hb

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

S Ebels

I concur HB

I have only one natural gas Vitodens installed, all the rest are LP. The natural gas fired unit was as clean as a whistle when we did maint on it this summerand it's going on 3 years of operation. The LP fired units on the other hand absolutely, positively MUST be cleaned every year. One unit in particular was to the point of locking out the burner after only 10 months of operation. The owner switched brands of LP and the gunk subsided to a more normal level. I have to wonder how much more of this we are going to see if gas quality/btu content becomes more inconsistent.

ALH_4

Same here

LP with a Vitodens has alwaye been more tempermental in addition to the "coffee grounds". It would be nice if Propane was a little more consistent.

-Andrew

hr

With imported NG

I suspect quality and calorific content will vary quite a bit. I know the guys in Utah have already struggled with imported gas being blended in with local stuff.

hot rod

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Constantin

More importantly...

... if the source of the coffee grinds is in the gas, is there a way to filter the gunk out? I.e. would a filter dryer for a HVAC system, for example, do an adequate job of capturing and retaining such particles (if they are particles!).

Or are we observing a non-solid that becomes solid as a result of combustion?

hr

At first

I thought the "grounds" were caused by the intake air they breath. My first run in was at a store with a very dusty parking lot. But the more I see and hear it seems to be an LP issue.

It been seen in a number of brands now according to posts and pics here at the wall.

Maybe it's the odorent they adds to the LP ?

hot rod

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Ron Schroeder

Maybe those LP

units need some cafine in the morning to get them going. Seriously Mercaptan is used in both LP and NG so I would dought that is the issue.

Bruce

Cosmo_3

hmm is that Colombian or Kenyan

Yeah I have seen it in the LP fired Vitodens also. Maybe someone who knows exactly what is in LP can tell us what it is.

How is LP made? Could be that when it is processed from crude oil these are the impurities that remain in solution compared to naturally occurring Nat Gas?


Cosmo

[Deleted User]

More information than you ever wanted to know about propane...

http://en.wikipedia.org/wiki/Propane

We had to have Viessmann come down and change out the copper gas trains on 3 boilers we installed in GrandJunction. Seems something in the gas was reacting with the copper and causing an oxide that plugs up the super fine inlet screen to the gas valve.

Also had three 199 Munchies that kept loading up their gas valves with gunk on natural gas in Downtown Denver. Local utility admitted that it was "dirt" in their mains causing the problem and offered to install a filter on the incoming service. THey didn't offer however to pay for my having to replace the gas valves on the boilers...

Yeah, you could say we have crap gas around here, for sure.

ME

Perry_2

Chemistry of LP and Natural Gas

"Natural Gas" is typically a mix of methane - the lightest hydocabon (CH4) and ethane the next lightest hydrocarbon (C2H6), with faint trace amounts of butane and propane. It remains a gas at fairly high pressues and low temperatures, and is cooled to below -256 F in order for transportation in the liquid form. As such, it cannot carry any significant amount of impurities. Occasionally when there are shortages they will blend in a small percentage of propane(C3H8) to streach the methane supply. This is done at regional distribution points during peak demand periods. Normally the propane level will be no more than 10% in the distribution pipeline when it is being used to streach "Natural gas" supplies.

LP gas is mainly a either a mix of propane (C3H8) and butane (C4H10), or just mainly propane depending on the part of the country and weather. Because these easily liquify (and even freeze) at low temperatures and pressures they often can have a lot more impurities in them.

LP tanks are actully full of liquid LP that remains liquid as long as pressure is maintained in the tank. The gas evaporates to replace the gas that just flowed out of the top of the tank to various appliances or burners.

For people in the northern areas - or mountains; you will have essentially pure propane LP gas for at least the cold months; because butane would feeze in the outdoor tank (have you ever seen a butane lighter freeze). During summer you may get a 50/50 mix of propane and butane. For those down south where it is always warm - expect to get mainly butane LP gas during the winters when the propane is shipped to the cold areas unless there is a surplus of propane.

Thus, LP gas can have substaintial changes in its properties based on season and demands - and can carry a lot heavier impurities with it because it is a lot heavier than methane or ethane.

Hope this helps,

Perry

Cosmo_3

Thanks

To Mark and Perry

Good info

Cosmo

Perry_2

and cars run on Octane

Gasoline is a mix of a variety of hydrocabons; but the original designation and concept (from a research perspective) was Octane which is C8H18.

It cost to much to separate out all the various hydrocarbon fractions arround Octane for it ever to be used as production gasoline. Just thought you would like to know what the model was - and why we measure gasoline performace by "octane" (100 Octane gas performs as if it were pure octane).

With gasoline with a higher concentration of lighter hydrocarbon contents you can get better than 100 octane; and a higher concentration of heavier hydrocarbons produce octane ratings less than 100.

Perry

paul lessard_3

on natural gas too

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

ALH_4

SS

We were in Waterloo last year, and they informed us all the new Vitodens were getting stainless tube instead of copper. Apparently they had enough problems that it seemed to be a pressing issue at that time. The last big stocking order we got while I still worked at RE in 2005 had a mix of copper and stainless. I presume they are all stainless by now.

-Andrew

heatboy

I suspect........

.....it is just a by-product of combustion. The strainers are absolutely clean when I check them. The same thing happens in a standard CI boiler, it's just the heat exchanger is 10 times larger, so you don't even notice it. Boilers need to be serviced every year anyway, so this seems to be a non-issue, if it is maintained.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Dave Yates (GrandPAH)_1

same here

NG - no grounds & remains clean as a whistle.

LP - Must clean every year to remove grounds that foul the HX over time. They don't dissolve in the acidic condensate either, so traps must be flushed to prevent clogs.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Mike T., Swampeast MO

Here (southeast MO) with natural gas as well.

Plumdog_2

Excell Gas

Engineer at excell energy told me the purity and the sulfide content of NG arriving in Colo. from the southern pipeline is well monitored; but when local gas is blended in when demands are reduced, crapola gets in with the good stuff. Anyone else find the oily residue that can fill up your gas lines and ruin gas valves? This is with LP gas.

Ron Schroeder

Oily LP

There is oil in LPG to help lubricate gas valves as I have been told, now those oils will collect in the bottom of tanks, and after many years there is quit a build up and it stinks a very rawnchy smell. How do I know? I had a customer flip one upsidedown an got oil all through the lines and valve, a nightmare to clean and the smell lasted on my hands for days. I was not well rercieved in AC class that night.

Bruce