quote:

Originally posted by 51fitter:
Not if the heat exchanger is built right, mine has a 6" tube with 1/8 inch wall on the inside, the flame is in this tube, the outer tube is 12" tube with 1/8" wall, in between the two tubes there is a helicle ramp the goes from the bottom to the top that forces the oil to travel round and round the inner tube about 20 times to the top where it exits, inside the flame tube there are half discs that cause the flame to travel a zig-zag up the tube, most of my heat is transfered into my oil.

I wasn't talking about the heat exchanger, I was refering to Glycol which will decrease efficiency if it is run through the boiler itself. And might I add with my "30 yrs plus experience" running glycol through a boiler is not all that uncommon. Example: when heating natural gas before it is sent through the meter runs it is first sent through a boiler filled with propylene glycol. The reason for heating the gas is after it is measured in the meter runs, it then goes through the regulators this rapid release brings the gas temprature way down, during a high demand peak period the regulators could easily freeze up and stay stuck in there position.(no more regulation!)

Example 2: when converting LNG back to a gas form, the LNG is run through a Propylene glycol bath boiler and then sent out for distribution to homes and bus.. This concept has been used for decades!


But getting back to the original thread the man is trying to use a conventional house boiler to heat his oil I'm just trying to help I have been doing this kind of work in the industrial environment all my life, this is my bread and butter, I will not be offended if someone does not want to use my advice. Be safe ......happy brewing![/QUOTE]

No harm no foul, I also believe a residential type boiler would be a bad idea.

quote:

Originally posted by fabricator:
A water heater either electric, gas or oil will take forever to heat 220 gallons of oil, just trying to make it circulate semi evenly would be quite a feat.

Got a suggestion on how to heat it. I have considered 2 4500 watt inline heater. I feel that my mixing will suffer slowing down the pump volume. I have considered idea of 3 4500 watt in tank chromalox heating elements. I have done the math ant this will bring the tank if insulated up to 140 degree's in 5-6 hours and 195 degree's in 16-18 hours. The idea of a boiler is foreign to me but I have considered a separate circulation and pump system for each system, the oil and antifreeze to circulate through a heat exchanger.A domestic water heater with antifreeze heated to 240 degree's with 2 4500 watt heater elements and a 20% efficiency loss in a heat exchanger would bring the oil up to 195 degree's in 22-24 hours. I use the fuzzy math concept(round number's and guessing at the variables)the advantage over in tank heaters is not having to drain the tank during mid processes and start over to change the heater elements because of the crust building up and killing the elements( have had a lot of experience with this in the damn Appleseed ). I have almost all the equipment in place but this is the next decision to make for the build.

quote:

I have considered idea of 3 4500 watt in tank chromalox

I'm sure you already know that you will need 60 amps @ 240V for that arrangement, make sure you have that kind of power available where you process. If I am stating the obvious just give me the word
Jon

My current biodiesel reactor is right beside the 300 amp commercial service where it comes into my business. With a dedicated 100 amp disconnect box and room for 10 breakers in it. My thinking is if I use electric heating elements I will save about 30-40% on electricity use. By doing 1 220 gallon batch as opposed to doing 4 seperate 50 gallon batches.

Yep, sounds like you've got it covered!
Jon

There is no question that electric elements are by far the easiest route, they just add a little extra cost per gallon, I use the folded 5500 watt eleemnt in my still and have never had one burn out, if you have a good flow rate it should no be a problem, what is the gpm of the pump you will be using?

using the 1-1/2 murphay pump projecting 70-94 gpm in my configuration is there any advantage in an electric boiler setup

That should be sufficient flow, no, there is no advantage to an electric boiler, if you just use elements in the processor you are heating the oil directly, if you go to a boiler you are losing efficiency by going from the elements to the heat transfer fluid to the oil, if you have elements in the processor you have 100% heat transfer.
One way to make the elements last longer would be to put the elements in the discharge plumbing of the pump, that way they always have have a high oil flow, if you had a series of Tees plumbed like stairs, you would use the Tee as an elbow with the element threaded into one of the straight through holes, the oil flows up the stairs and the elements are constantly bathed in a flow of oil.
You could put valves on each end to isolate the elements in case yoy need to change one.

the disadvantage of the inline heater is for every 90 you use there is the resistance in flow equivalent to 10(?) feet of pump head pressure added. I just had a great idea! My boiler idea was going to use a separate circulatory system why not use the same secondary circulatory system for an inline heating system and improved mixing as a bonus!! I agree that insufficient circulation contributes to element failure. Usually when I change elements I have to vacuum out 4-5 gallons of sludge that has accumulated in the bottom of the Appleseed.

That'll work fine, I've built several processors that had seperate heating circuits.

quote:

My boiler idea was going to use a separate circulatory system why not use the same secondary circulatory system for an in-line heating system and improved mixing as a bonus!!

Here is a great little hermetically sealed flow switch that will work great inline of your heater circuit, no flow no heat, works great...
Flow Switch
Jon

Hello, My solution to heating 400 gallons of WVO outside, works like this.
My raw oil heater tank is a former 500 gallon fuel tank, with a 275 gallon fuel tank, now used as a wood fire box, with one side cut out of it, welded directly to the bottom of the 500 gal. tank. These two tanks are mounted on a farm running gear, with four wheels and a towing bar to be mobile. It has a 12" dia. smoke stack coming out of the wood fire box.
The 500 gal. tank is insulated, just on the top half of tank, with fiberglass insulation and covered with sheet metal.
It has 2-Fill holes on top, 3-2" side outlets and 1-2" bottom drain outlet, each with 2" ball valves. Pack with wood and start the fire and you have all the BTU's you need. We load and unload oil with 1" diaphram pumps and fuel suction/delivery hose with cam locks. No vinyl hoses that can burst under pressure and burn you with hot oil. (I'm getting smarter lately.)
Main cost; Our own labor
other costs; Old Running gear = free
500 gal. fuel tank =$250
275 gal. fuel tank =free
4-2"Stainless ball vales $160.00 on e-bay
insulation =$30
sheet metal=$45.00
Heating 1200 gallons of cold oil takes alot of energy. My system works great outdoors. The fire hazard is limited to the tank of oil itself, since it is way out back. Any flat bottom steel tank could be welded on top of a wood fired, steel box for maximum heat. Electric heat was way too slow for me. This system is the next best thing to a fire-in-tube heater tank. I looked at the portable asphalt tanks that are used on the highway, they use gas/fuel fired torches on some designs. My first choice would have been a steam coiled tank, but that required a boiler or steam source. I used this style on a semi tanker to heat molten sulfur at Exxon Mobil. Steam coils running inside the bottom of a tank are clean and really put out the heat. Anyway, my goal here was a low cost heater tank and this works great. We heat oil outside and pump it inside building, into the processor already hot.

quote:

CSCHAEFER

Do you have a picture of your setup? Sounds interesting but just can't visualize what you're describing.

Our Heat Exchangers are probably a large source of heat loss, they're made out of 3/4" black iron, and are about 6-8 feet long, 1' wide section arranged like a ladder.

So let's say that I'm trying to get to 220F, and reasonably quickly (hours not days), for 1000 gallons of oil... you guys think Steam boiler, and about how big of a steam boiler?


This residential boiler is cute and all, but getting tired of the fooling around !

If anyone can lend an ear to where I can locate a good used steam boiler, and all that I need, I'd appreciate it.


Thanks for all of the replies and insight, I love the pursuit of knowledge

I use an emerald residential boiler, 140,000 BTU unit. I run oil directly through it and can heat 500 gallons of oil from 60 degrees F to 140 degrees F in two hours. That is also including heating the steel of the processor.

After several thousand gallons of bio, I have yet to have a problem with it.

I did originally use a heat exchanger, what a waste of time.