Attn: S & M members...we have a job....

Alright, we seem to have a full complement of staff here at S & M that are chomping at the bit for a project. I would like to enlist the help of all the staff on a project that I need to be working on but just don't know which way to proceed.

I am working on a digester tank system that has multiple tanks,"x", each of which needs to be separately monitored for temp, PSI, amount of gas in and out, and level. Some may also need other sensors, such as COD or BOD, Turbidity, etc.

This is a Pilot system, so I must collect as much data, of the right type, as I can.

Oh, and the tank system produces CO2, hydrogen sulfide, and methane gases, so the data network will be in a potentially explosive atmosphere.

My question is : What are my options for this type of system?

Lets see how good S & M really is!!!!

David ( AKA: Suds Walla):site:

Well First thing we will have to do is set up a sub committee to establish the parameters of the fees..If this goes well then another committee will put together a proposal for billing dates and milestones..Only once that has been approved by the customer..and the 90% down payment has been received and cleared by the bank we can proceed further..Dont worry about the specs of the job..we will make them up and change them as required..

Darren. (Executive President of Growth)

What a scenario. Acid gas is methane gas that can have hydrogen sulfide, and other content which needs to be removed before use. When burned methane (natural gas) releases CO2 and H2O (water).

Will the CO2 tank be at ambient temperature?

Thats about as far as my chemistry goes for now except those 3 would make a very dangerous greenhouse.

I do not have a clue if this scenario is real but am would like to see a discussion as if it were. Is this an experiment using sheep droppings?

This is a real project, and yes, it involves sheep poop.

David

I would like to appoint myself as chief accountant and would therefore request all down payments concerning this project be forwarded to me.

First things first

Before you can begin, you must first determine the electrical classification of the area. This should be done by someone or some group that is qualified. The rating of the area will have a large effect on the type and cost of the instruments you can use. Class I Div. I, is a lot harder to deal with than Class I Div. II. Many of the industrial data networks are not suited for explosive atomsphere's without a lot of extra effort. This application is not that unique in it's hazards, chemical companies handle similar hazards day in and day out. However, it will make the cost much more.

As an aside, will this system require a safety interlock system? Has a Hazop (Hazardous operability) or PHA (process hazard analysis) been preformed? What about air permits? How many tanks, when you reach certain quantities additional regulations kick in, such as OSHA PSM (process safety management).

Just a few things to chew on.

Ian

Sorry, there won't be any down payments. That comes from geese and ducks. All you'll get here is **** payments.

Ken

rsdoran said:

When burned methane (natural gas) releases CO2 and H2O (water).

Click to expand...

Somebody mention burning? Count me in.

Burnerman
Combustion Engineer
(legalised arsonist)

darrenj said:

Well First thing we will have to do is set up a sub committee ...
then another committee will
..and the 90% down
..we will make them up
Darren. (Executive President of Growth)

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Hum, Ottawa - Canada.

Now they all know why we have so high taxes

I am working on a digester tank system that has multiple tanks,"x", each of which needs to be separately monitored for temp, PSI, amount of gas in and out, and level. Some may also need other sensors, such as COD or BOD, Turbidity, etc.

Click to expand...

Methane is flammable and hydrogen sulfide is flammable and toxic. I do not know at what "level" flammable becomes explosive so an assessment would be needed to determine the Hazardous rating.

That aside since all 3 are gases I do not get the need for "level" because gas expands to fill a container equally. In some cases if pressure is high enough there can be a liquid state but I am not sure how relevant that could be....for CO2 its over 5 atmospheres.

I do not know enough about the process but would probably have flowmeters for both in and out, this works with temperature and pressure to offer accurate measurements.
http://www.omega.com/toc_asp/frameset.html?book=Green&file=MASS_FLOW_REF

Turbidity I dont know, thought that was normally done on soil/water.

B.O.D., isnt that biological oxygen demand? How is that relevant?
COD I do not have a clue at this time what it means.

Based on where the non-hazardous area is related to the hazardous area you may want to look at ControlNet (over copper) with a barrier. I have used that in an explosives mfg area and it works well with the 1797 FLEX EX I/O. Just some general comments is to locate the power supplies as close to the FLEX EX blocks as possible (right next to point of use would be best). Also read the tech documents. The number of supported nodes decreases as the length of the network increases. If you need long distances then you will need to use fiber controlnet and of course the cost goes up, but the barriers for the standard copper controlnet works well, just read the instalation documents before designing system.

At least I think I have seen you posting a lot on the A-B related items. If not, then you should look more to Foundation Field bus. There are some solutions for that that will work in a hazardous area. I'll have to look around to see what we have used last.

Darren

I think we should focus our attention on a sheep that doesn't poop.

A 'poopless' sheep would continue to expand, thus providing more surface area for wool. What a concept. And when it finally dies then there would be so much more sheepskin for diploma mills.

er...(ahem!) does anyone else find the title of this thread a little um...well...you know.

maybe my minds just in the gutter ( ok, i'm a guy. my mind is always in the gutter ) but this line really did me in. =]

Lets see how good S & M really is!!!!

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sorry david. i just couldn't help myself. =]

Hi group...Sorry it has taken me so long to get back here...we are in the middle of a major tear-down and rebuild of one of our plants, and have not had much time to get o-line.

Ron, the tanks are about 3/4 full of a slurry of mixed poop and water, not just the gas mix.

I will respond more later today, when I get back to the shop and can get on DSL again...this dial-up is about the worst I have ever had to put up with in a long time........
David