Yesterday (November 02, 2008) the boiler shutdown. I opened it up and discovered a different clog then I previously enjoyed. Normally the clog has been on the air slots on the combustion head; the clog has historically been a part-pasty, part-crispy mess (I call it coke). This clog was the same consistency as usual but now around the circumference of the burner's secondary air supply holes. There are about 10 or 12 1/4" holes around the combustion head that supply additional air to the fire. A few of these holes were obscured with the coke. It appears the Delevan nozzle I'm using (instead of the Hago nozzles I used last winter) put the coke in a different spot. This coke was easier to remove then the previous mess on the retention head; this is progress.
I have still not put in my Delevan Pro-Tek nozzle valve, I want to see how the non-valved nozzle behaves and if the check is necessary. So far it does not appear to be a needed thing; winter is here so we'll see more soon.
Monday, November 3, 2008
Thursday, September 25, 2008
Shutdown, clogged nozzle
One day after setting up the boiler (cleaned fire side, new rayon pre-filter, same old spin on filter, same nozzle from March, 2008) the boiler shutdown. I reset it and observed a very weak flame. I diagnosed the issue as a clogged nozzle. Tomorrow I will buy a new felt pre-filter, a new spin on filter and new nozzle) and install them and reset the boiler. Below is a picture of one day's worth of operation on the combustion head (I cleaned it thoroughly yesterday).
Here is a picture of the back of the combustion head (I did not clean this yesterday, it hasn't been clean since March, 2008).
Here is a picture of the back of the combustion head (I did not clean this yesterday, it hasn't been clean since March, 2008).
Annual boiler cleaning
I cleaned the boiler on September 23, 2008
Here is a picture of a new type of brush I picked up this summer; it is much improved over round brushes I used in the past. It is a wire brush and its shape is optimized for the space between the pins.
Here is a picture of all the soot knocked down from the upper section of the boiler; I do not know how much is from last winter's B100 and how much is from the previous home owner's lack of maintenance. Next autumn will be telling.
Here is a picture of the combustion head before cleaning; it wasn't too bad with coke, but not perfect either.
Below is a picture of the top of the boiler after cleaning. You can see on the left side the fiber rope is missing, gone. The features where the smoke hood (not seen in this picture) flange down onto the cast iron have rusted away. It looks to me like there was a long-term leak from above down into this area of the boiler and the iron and sheet metal smoke hood rusted away.
Here is a picture of the tapered nylon I like to use after the steel brush is done, it knocks of the dust nicely (the steel brush does a great job of knocking the heavy soot off).
Here is a picture of the brush, it is not round, which makes it much easier to use; a real improvement over other brushes I have used.
Part of the cleaning included a new pre-filter upstream of the spin-on filter. As a reminder I was running a 50 micron felt pre-filter (General 1A canister type) and then a 10 micron spin on filter. At the supply house I saw they offered a 50 micron felt unit or a 20 micron rayon unit. I bought the rayon element.
Before I put the element in, I consulted with my excellent B100 dealer. He suggested rayon would not be compatible with B100. I decided to install it as an experiment; we are only using the boiler for hot water right now and our electric unit is still hooked up, just valved out.
After the cleaning I did combustion testing and set the boiler up; 350 gross stack temperature and 11% CO2 (good for 83.2% efficiency, NICE!). At the same time, I finished up the domestic hot water piping and we started using the boiler/water heater for DHW.
Here is a picture of a new type of brush I picked up this summer; it is much improved over round brushes I used in the past. It is a wire brush and its shape is optimized for the space between the pins.
Here is a picture of all the soot knocked down from the upper section of the boiler; I do not know how much is from last winter's B100 and how much is from the previous home owner's lack of maintenance. Next autumn will be telling.
Here is a picture of the combustion head before cleaning; it wasn't too bad with coke, but not perfect either.
Below is a picture of the top of the boiler after cleaning. You can see on the left side the fiber rope is missing, gone. The features where the smoke hood (not seen in this picture) flange down onto the cast iron have rusted away. It looks to me like there was a long-term leak from above down into this area of the boiler and the iron and sheet metal smoke hood rusted away.
Below is a close up of the sections post-cleaning. Nice.
Here is a picture of the tapered nylon I like to use after the steel brush is done, it knocks of the dust nicely (the steel brush does a great job of knocking the heavy soot off).
Here is a picture of the brush, it is not round, which makes it much easier to use; a real improvement over other brushes I have used.
Part of the cleaning included a new pre-filter upstream of the spin-on filter. As a reminder I was running a 50 micron felt pre-filter (General 1A canister type) and then a 10 micron spin on filter. At the supply house I saw they offered a 50 micron felt unit or a 20 micron rayon unit. I bought the rayon element.
Before I put the element in, I consulted with my excellent B100 dealer. He suggested rayon would not be compatible with B100. I decided to install it as an experiment; we are only using the boiler for hot water right now and our electric unit is still hooked up, just valved out.
After the cleaning I did combustion testing and set the boiler up; 350 gross stack temperature and 11% CO2 (good for 83.2% efficiency, NICE!). At the same time, I finished up the domestic hot water piping and we started using the boiler/water heater for DHW.
Wednesday, April 9, 2008
Tank acclimation?
So with the newest two week operability information in hand, we discussed the situation with the chemist-entrepreneur-biodiesel provider. Since the last shutdown we cleaned the combustion heat and ran two weeks, then a shutdown (clogged combustion head, see other posts). After that cleaning we ran two more weeks (no shutdown). We opened the boiler up and it was nearly whistle-clean (why are whistles considered clean?).
In discussing this with the chemist, he opined our tank acclimated to B100 and stopped sending gunk into the burner. We like this idea and will keep our eyes on the situation in coming months. Perhaps the B100 puzzle is beginning to unravel:
When switching to B100:
1. Put the better filter in.
2. Install the line heater.
3. Use a smaller nozzle and jack up the pressure.
4. Suffer some pain with shutdowns as the tank's existing junk stop reacting with the B100.
Of course we don't know if this will work, but we are hopeful (less for us, more for others to start using B100).
In discussing this with the chemist, he opined our tank acclimated to B100 and stopped sending gunk into the burner. We like this idea and will keep our eyes on the situation in coming months. Perhaps the B100 puzzle is beginning to unravel:
When switching to B100:
1. Put the better filter in.
2. Install the line heater.
3. Use a smaller nozzle and jack up the pressure.
4. Suffer some pain with shutdowns as the tank's existing junk stop reacting with the B100.
Of course we don't know if this will work, but we are hopeful (less for us, more for others to start using B100).
Monday, March 31, 2008
Process flow diagram
OK, a favorite chemical engineer of ours asked for a process flow diagram. I hope this chemical engineer wants a schematic of our oil supply system. If that engineer wants a PFD of the biodiesel conversion, she will have to contact our biodiesel supplier or perhaps crack a chemical engineering textbook from that engineer's fancy engineering college (Go Bears!).
Here is a hand-done schematic of our oil supply system. Obviously our ability to burn B100 is not related to penmanship.
Here is a hand-done schematic of our oil supply system. Obviously our ability to burn B100 is not related to penmanship.
Monday, March 17, 2008
Another shutdown, clogged flame retention head
Tonight the boiler shutdown. I opened it up and discovered the expected coked up flame retention head. I cleaned it with some acetone, a gasket scraper, a small wire
brush and a flattened piece of 10 AWG solid copper wire. After 20 minutes of cleaning, I closed the door, started the boiler up again and had good flame.
brush and a flattened piece of 10 AWG solid copper wire. After 20 minutes of cleaning, I closed the door, started the boiler up again and had good flame. We went from March 01, 2008 to today (March 17, 2008) before needing to clean. That is not really improved since the before the nozzle check valve and nozzle heater.
Next I will order a Delevan nozzle check valve and try that with a new Delevan nozzle. The two pictures on top are the "post" cleaning and the four pictures on bottom are the "pre" cleaning.
We will keep trying and monitoring.
Monday, March 3, 2008
Why did the nozzle clog?
The clogged nozzle mystery. I discussed this with the refiner/seller. His thoughts include:
1. The adhesive in the cardboard spin on oil filter (10 micron unit) may dissolve in the B100, then clog the nozzle.
2. The epoxy coating in the spin on filter can may dissolve in the B100, turning into shellac in the nozzle after shutdown, clogging the nozzle.
3. The refinery filters are not as good as they think they are. The refiner is in the process now of particle size testing and filter upgrades.
One easy solution is to put a bigger nozzle in and lower the pressure. I do not like this solution. The current scientific plan between the refiner and me is to keep the nozzle size the same (0.65 GPH, 60 degree, semi-solid) and see if the first nozzle clog was a fluke, or if it happens again. The refiner will also try to rig up an experiment with the filter and a pump. He will run the B100 through the filter for days on end, then compare that oil with un-circulated oil in his "GC." If you are cool like me, you know GC means gas chromatograph. If you don't know what a GC is, look it up on wiker-pedier. We'll find out if the filter is causing nozzle clogs.
Here are some pictures to enjoy.
Here is the combustion head after cleaning (the chemist/refiner/retailer) suggested acetone; it worked great.
Another shot of the cleaned head.
Here is complete assembly, ready to go back in the boiler
. Those of you in the know will spot the oil line heater.
. Those of you in the know will spot the oil line heater.Timeline, some tribulations
We purchased our first 250 gallons of B100 in January 2008. The refiner/seller gave this advice, which we followed:
1. Replace the oil pump with one that is B100-compatible. B100 is very rough on rubber (my rubber gloves disintegrated working with it). The new oil pump has Viton seals instead of Nitrile.
2. Add a 10 micron oil filter, downstream of the 50 micron unit. Why? B100 may cloud (imagine congeal) below about 50 degrees, forming biowax. These biowax particles will clog your nozzle. Also, putting B100 in an old oil tank will dissolve everything in the tank and push all the sludge into your nozzle. The 10 micron filter will help protect your nozzle.
3. Change the flame detector to one with a wider band. The standard flame detector does not see the B100 flame the same and may cause nuisance trips of the flame safety.
4. Downsize the nozzle and raise the pressure, to decrease oil droplet size in the furnace section, for better combustion. We did not do this at first, we did not have new nozzle.
We put the new pump and filter in-place and set the burner up. Our refiner is still new in this business and is learning along with us. We are a "high-beta" site for him. I really like our refiner, he is a chemist by training, but is really a startup business person. I believe in his product and I want to make it work for me and him.
After running a few weeks with this setup, we experienced the expected afterdrip problem. In running any fuel, there is always a tiny little drip of fuel that drips out of the nozzle after cutoff. Even with a perfectly functioning pump cutoff (or in our case, oil solenoid valve), there is a little bit of unburned fuel that falls out of the nozzle. With fossil fuel, this drip burns off right away, but the viscosity and combustion properties of B100 does not let it burn right off. Instead it turns into a sticky, crusty mess of coke on the flame retention head. Eventually the coking closes enough of the air slots in the retention head and prevents combustion, causing flame failure. This happened to us.
I was away on business when the flame failure happened (about January 30, 2008). With clear telephonic instructions, she was able to open the boiler door, chip off the crud and restart the boiler. Jen is an awesome mechanic.
After returning from that trip, I put the smaller nozzle at higher pressure in the boiler. This was on a Sunday evening (February 17, 2008) before another trip (in real life I have a job that currently requires a bit of travel). On Monday evening after landing in an airport, I receive a message "no heat, call right away." Turns out when I adjusted the burner the day before, I forgot to tighten the screw on the secondary air band, so in 24 hours it loosened up and went out of adjustment, causing a no-flame condition. With more telephonic instruction, Jen was able to relight the boiler, adjust the flame by eye and tighten the band down.
The following Monday (February 25, 2008) we awoke to no heat. This time I went downstairs and watched it go (after resetting the primary control). The flame lit, ran weakly then extinguished. The nozzle was evidently clogged with something (more on that mystery later). I changed the nozzle and restarted, no problem. Nozzles should last longer than 8 days though.
That Friday (February 29, 2008) we purchased 110 gallons of B100. We also bought a line heater and a shut-off valve for the nozzle. The line heater goes on the oil line, inside the blast tube, just upstream of the electrode holder. This 12 watt heater works to warm the oil line to 140 degrees F. We gain a few things with hot oil. We have lower viscosity (better atomization) and will "remix" any clouded components of the oil (from traveling across the state in cold weather).
We also added a Hago oil shutoff valve (medium pressure, MC). This valve is supposed to close below 135 psig, reducing the amount of afterdrip, hopefully expanding the time between services. We'll watch closely.
Bill N.
1. Replace the oil pump with one that is B100-compatible. B100 is very rough on rubber (my rubber gloves disintegrated working with it). The new oil pump has Viton seals instead of Nitrile.
2. Add a 10 micron oil filter, downstream of the 50 micron unit. Why? B100 may cloud (imagine congeal) below about 50 degrees, forming biowax. These biowax particles will clog your nozzle. Also, putting B100 in an old oil tank will dissolve everything in the tank and push all the sludge into your nozzle. The 10 micron filter will help protect your nozzle.
3. Change the flame detector to one with a wider band. The standard flame detector does not see the B100 flame the same and may cause nuisance trips of the flame safety.
4. Downsize the nozzle and raise the pressure, to decrease oil droplet size in the furnace section, for better combustion. We did not do this at first, we did not have new nozzle.
We put the new pump and filter in-place and set the burner up. Our refiner is still new in this business and is learning along with us. We are a "high-beta" site for him. I really like our refiner, he is a chemist by training, but is really a startup business person. I believe in his product and I want to make it work for me and him.
After running a few weeks with this setup, we experienced the expected afterdrip problem. In running any fuel, there is always a tiny little drip of fuel that drips out of the nozzle after cutoff. Even with a perfectly functioning pump cutoff (or in our case, oil solenoid valve), there is a little bit of unburned fuel that falls out of the nozzle. With fossil fuel, this drip burns off right away, but the viscosity and combustion properties of B100 does not let it burn right off. Instead it turns into a sticky, crusty mess of coke on the flame retention head. Eventually the coking closes enough of the air slots in the retention head and prevents combustion, causing flame failure. This happened to us.
I was away on business when the flame failure happened (about January 30, 2008). With clear telephonic instructions, she was able to open the boiler door, chip off the crud and restart the boiler. Jen is an awesome mechanic.
After returning from that trip, I put the smaller nozzle at higher pressure in the boiler. This was on a Sunday evening (February 17, 2008) before another trip (in real life I have a job that currently requires a bit of travel). On Monday evening after landing in an airport, I receive a message "no heat, call right away." Turns out when I adjusted the burner the day before, I forgot to tighten the screw on the secondary air band, so in 24 hours it loosened up and went out of adjustment, causing a no-flame condition. With more telephonic instruction, Jen was able to relight the boiler, adjust the flame by eye and tighten the band down.
The following Monday (February 25, 2008) we awoke to no heat. This time I went downstairs and watched it go (after resetting the primary control). The flame lit, ran weakly then extinguished. The nozzle was evidently clogged with something (more on that mystery later). I changed the nozzle and restarted, no problem. Nozzles should last longer than 8 days though.
That Friday (February 29, 2008) we purchased 110 gallons of B100. We also bought a line heater and a shut-off valve for the nozzle. The line heater goes on the oil line, inside the blast tube, just upstream of the electrode holder. This 12 watt heater works to warm the oil line to 140 degrees F. We gain a few things with hot oil. We have lower viscosity (better atomization) and will "remix" any clouded components of the oil (from traveling across the state in cold weather).
We also added a Hago oil shutoff valve (medium pressure, MC). This valve is supposed to close below 135 psig, reducing the amount of afterdrip, hopefully expanding the time between services. We'll watch closely.
Bill N.
Introduction, why B100, our setup
We decided to use 100% biodiesel in our home heating system this year. We buy our fuel from a local refiner who converts waste or used vegetable oil into biodiesel (B100). Lots of people burn B5 (meaning 95% fossil fuel, 5% biodiesel). Some people think they are doing good with B20. We decided to go all out and burn B100.
Why?
1. Shell Oil and Exxon-Mobil do not operate refineries in our state. Burning B100 puts jobs here.
2. There are lots of studies and anecdotal evidence to show burning B100 is cleaner/better than fossil fuel (carbon in the air, particulates, renewable, recycle used oil, etc).
3. It is about 20% less expensive then fossil fuel. We just bought 110 gallons for $2.80 a gallon. Cash price in the New York metro area (cheaper than what we could buy it for) is $3.40 a gallon.
There are problems with B100. I hope to share our experience and perhaps inspire you to burn B100 instead of fossil fuel.
Our setup:
We use our boiler to provide space and domestic hot water heating. The domestic is not hooked up yet, but sometime this winter it will be (we have an Ergomax water heater). The house is divided into seven zones (two zones are off, they are the basement and the garage).
The boiler is in the garage, next to the oil tank. We have no chimney (we have a sideshot induced draft fan). Currently we use indoor air for combustion, the future hope is to use outside air, after the boiler room wall is built.
We have a Burnham V8 boiler with a Beckett AFG burner. The "design" nozzle for this unit is 1.1 GPH, 60 degree, B at 140 psig. I believe this is too big, espicially considering our tiny zones (all zones never, ever call at once). We have a "V1" combustion head.
We currently are running a 0.65 GPH, 60 degree, semi-solid at 180 psig. Our B100 refiner believes increasing the pump pressure is important (B100 is about two times as viscous as #2 oil at any temperature) to decrease droplet size.
Bill N.
Why?
1. Shell Oil and Exxon-Mobil do not operate refineries in our state. Burning B100 puts jobs here.
2. There are lots of studies and anecdotal evidence to show burning B100 is cleaner/better than fossil fuel (carbon in the air, particulates, renewable, recycle used oil, etc).
3. It is about 20% less expensive then fossil fuel. We just bought 110 gallons for $2.80 a gallon. Cash price in the New York metro area (cheaper than what we could buy it for) is $3.40 a gallon.
There are problems with B100. I hope to share our experience and perhaps inspire you to burn B100 instead of fossil fuel.
Our setup:
We use our boiler to provide space and domestic hot water heating. The domestic is not hooked up yet, but sometime this winter it will be (we have an Ergomax water heater). The house is divided into seven zones (two zones are off, they are the basement and the garage).
The boiler is in the garage, next to the oil tank. We have no chimney (we have a sideshot induced draft fan). Currently we use indoor air for combustion, the future hope is to use outside air, after the boiler room wall is built.
We have a Burnham V8 boiler with a Beckett AFG burner. The "design" nozzle for this unit is 1.1 GPH, 60 degree, B at 140 psig. I believe this is too big, espicially considering our tiny zones (all zones never, ever call at once). We have a "V1" combustion head.
We currently are running a 0.65 GPH, 60 degree, semi-solid at 180 psig. Our B100 refiner believes increasing the pump pressure is important (B100 is about two times as viscous as #2 oil at any temperature) to decrease droplet size.
Bill N.
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