Starting a boiler without oil or gas

[athomas236]

I am working on a specification for a 6MWe(net) wood burning plant and the environment permit states that no fuel oil of fuel gas shall be burned on the site.

Two types of boiler have been specified, a vibrating grate and a bubbling fluidised bed.

Without gas and oil, any ideas about how to start the boiler.

In about 1963, I did start a travelling grate shell boiler with a bundle of firewood and a newspaper from the local shop but I thought things maight have moved on.

Regards,

athomas236

 

[MJCronin]

atom.....

I worked on a couple of Waste-to-Energy boiler plants with travelling trash grates...... with the same kind of start-up problem as you have.

The older plants used a case full of railroad flares to get things started. Sometimes they worked.....sometimes not

Recognizing the problems and delays inherent with the flare method, the newer plants has a carefully monitored "startup" gas system.

Because of the agreed upon bookeeping system ,the authorities watched how much gas was consumed to ensure that payments were not made for startup gas instead of trash burned.

-MJC

 

[macmet]

I work for a company that does solid fired boiler systems and we often still use the handmade fires to start. We also sometimes use propane torches to light it through the firedoor or diesel soaked rags. I'm not sure if those methods go against your permits though.

I have seen more and more customers switch over to the natural gas start-up systems like described by MJC.

 

[rmw]

The wood fired (largely sawdust and bark) systems that I worked on that had no auxiliary fuel always typically had a ready supply of dry fuel like planer shavings. They always had to be careful to operate so that at shutdown they ended up with dry shavings in the feeder bins-not wet fuel.

A pile of planer shavings were fed onto the grate and it was started with the aid of some oily rags soaked in diesel. I take the specification to mean that there will be no permanently installed gas or oil systems, not that they can't splash a little diesel on whatever the start up fuel is.

If you don't have planer shavings available, then cobble up a supply of other types of dry wood e.g. busted up pallets, construction wood waste.

It is just like the Boy Scouts; start with dry kindling and build up from there.

rmw

 

[davefitz]

first: find out if they will give you a waiver for firing a biomass-generated oil as startup oil- then you will need to shop around for a supplier of this boutique stuff- and the permit issuer will want to check to see if you are cheating by substituting fuel oil.

second- if the unit is expected to be 2 shift cycled, then a fluid bed unit makes the most sense- during nightly shutdown just slump the bed hot ( 1500 F) and purge using above bed overfire air only. The bed will remain hot overnight - on restart, just feed wood above the bed, then fluff the hot bed to ignite the surface wood, keep repeating until there is enouhg burning wood inventory to sustain normal fluidization.

the initial fires of a cold fluid bed will be a tough nut to crack- may need a special one time per year use of startup oil- may use a biomass oil for that event as well.

 

[DIRTYDAVE]

Scrounging around a construction site gathering scrap lumber and then starting a "campfire" in the furnace was the fun part of being a boiler manufactuer's start up engineer.

 

[boilerone]

The easiest way I believe is to go to your local grocery and get bags of the easy-to-light charcol fuel for BBQ and they will serve the purpose. If need to start up fire frequently then do like the others say so as to save money.

 

[athomas236]

Gentlemen,

Thank you all for your helpful advice and sorry for slow response.

Whatever way you look at it, a boy scout will be useful.

Thanks again.

athomas236

 

[chicopee]

You may want to contact Zurn boiler sales people for such info. Zurn makes wood chip burning WT boilers.

 

[athomas236]

Thanks chicopee

Regards,

athomas236