Californian Shasta 2 Gasifier and Boiler
In the two years since the beginning of the all new linear hearth Shasta
Class Gasifier project, we have shown the progress of the development
work at CalForests in California. As much as one might appreciate,
design in it's self, as is innovation, provides no guarantee that it
will actually work reliably in a commercial situation. As the testing
hours gradually accumulated, so did the incident of component failure,
but not always the components that we built, because some very expensive
bought in assemblies, failed in their application when exposed to the
extremes of a gasification system. Testing to destruction has been a key
driver behind the evolving design of the Mk 2 Shasta Class system,
which after another eight months testing to an open flare, has now begin
the testing the next phase of this programme, fuelling a hot water
Unfortunately, a operating gasifier has little to see by way of moving parts, as the only thing moving is the fuel supply system, and even that is stationary most of the time as part of a timed cycle. However, a video of the Laimet Screw chipper has be made during this latest set of photos to supplement the information about this form of fuel chip preparation. http://youtu.be/9DRnfXQas9M
As all the installation is located out in an open environment, freezing Winter conditions still sees huge amounts of waste heat available from the gasifier casing so the Mk 3 Shasta will incorporate water jacketing, probably fed from the colder return line of the water circulation from the greenhouse. Now that the boiler is operational and the radiator heat exchangers are in place, the need for heating begins in earnest during February. In this respect, the maximum heating output from the system potential has not been established, other than it is more than the output of the five installed heat exchangers installed for this glasshouse. A plan is in place to extend the hot water pipes to ground heat a large outside area adjacent to the end of the greenhouse, further improving the growing options.
It is appropriate to say that the uncertainty of supply and higher price of LPG at this time in Northern California, is indicating a saving over costs of around US$300>/day. The economics are like the gasifier and need to be tested, but can only happen as their order in the project comes into effect.
Finally, I should remind those following this project, that this blown hot gas gasifier, has only high performance gas cleaning cyclones, and no ceramic candle filtration is used for the boiler. This now requires a further round of emission testing which is easy to do, now that the testing equipment has been purchased for this seasons heating programme.
|This shows the hot water boiler (insulated square grey box) now connected to the previously open flare of the gasifier. Under ground isolated pipes take the water to the greenhouse seen in the rear of the photo. The black hole on the end of the boiler box is the missing flu connection.|
|View of the combustion chamber through the inspection port of the boiler during the first start-up of the boiler 14th January 2014.|
|In start-up mode on a very cold morning, flu gas is exiting as condensing steam from the boiler flu connection port.|
|Now at operating temperature, the heated flu gas is well above the steam condensing temperature, and nothing moves until the next refuelling cycle.|
|The hot water is piped to the Greenhouse underground where the circulating water pump station can distribute the flows to the overhead radiators.|
|Mounted over head next to older LPG heaters, the new hot water radiators supplied from flexible piping make it easy to retrofit for this application. There are five of these new radiators installed for this Winter heating test programme.|
|Now seen after operating for a few days, the very fine carbon blacks remaining in the gas, combust into very fine white ash. This was expected, and is catered for with ash blower ports adjacent to these cast projections, but the cleaning cycle has yet to be established. It is expected that particulate emissions will be below the allowable thresh-hold.|
A quick puff and the ash deposits are cleared from the cast projections, a system that will be automated at a later date. For this heating season regular visual inspection will establish how these surfaces coat across the automated variable heating output of the boiler.