Fluidyne Update December 2004
Hi Gasification Colleagues
I promised to provide regular reports on the Mega Class Gasifier development in Canada, but since and during my September/October visit, the weather has been quite a problem at the installation. With never ending rain, just trying to keep the prepared chip fuel dry in the large quantities that we were using taxed everybody's patience. With winter and snow now present, a fuel preparation building is being constructed and a special high speed docking saw installed to handle another line of waste wood.
We have also located a trailerised hogger, and the reports on its performance indicate a long term solution to fuel chip preparation. I hope to show photos of it in action on site.
During this visit to continue the componentry development for the winter test programme, I built a "Cyclonic" burner nozzle for the oxidation tower. We developed this burner nozzle back in 1984, and by installing this one in the tower, combustion of the gas can be done without soot formation. It runs at about 10 MWt, but it has plenty of scope to increase the output if we push the gasifier harder later in our tests. Although we have run at 2.5T/hr, current testing is being held down to 2T/hr while we monitor the cooling system behaviour, then we will start the maximum output trials next summer.
In the Canadian environment, we have a seasonal climate change that provides the extremes of temperature a gasifier must be able to handle in the different environments of installations. The final design concept has all the gasifier components encased to control heat and air flows in both directions depending on climatic conditions, but we are leaving that until last when we are satisfied with the configuration plans.
On my last visit in June/July 2004, a design for the gas cooler was prepared to add to the first stage of the condenser/cooler. This has now been built and installed and is working to expectations. While cooling technology is well established, cooling producer gas has its own special needs, and off the shelf equipment did not provide an optimised design for our needs. From past experience with small scale systems, an opportunity existed to test a number of ideas within the design to extract the maximum heat out of the gas. This also improves the removal of condensing moisture and the carbon blacks which it carries.
With these major components now in place, emission tests are to be completed before Christmas 2004, and then the final stage of running the multiple engines can proceed. I should mention that winter emission tests are not valid for EPA test procedures and the EPA tests will follow in the summer. We do have a technical hitch with the alternator being 600V, making it difficult to hook into the grid, but steps are being taken to use the power on site to run the timber driers at the adjacent mill.
Photos of the Cyclone Burner can be seen on the Fluidyne Archive - www.fluidynenz.250x.com
These cluster cyclones have been well tested since this photo was taken. The collecting performance matches samples from previous work in Northern Ireland and Germany. The carbon and ash are very fluffy resembling talcum powder (about 10 micron). About 90% of the particles that escape cyclones are sub micron in size, and these have to be removed by other means to prevent their adding to an excessive particle emission count.
This is the 'Cyclomix Burner' which has been designed to slip onto the gas inlet pipe of the oxidation tower, and connect to a fan for combustion air. Air and gas come in from opposing tangents, meeting and mixing just inside the outlet. No diffuser or swirl plates are required to hold the flame onto the burner, in fact the flame is impossible to blow off if gas is present to maintain ignition.
Here is a sample of the wood chip made from the Blow Hog machine. The chip is quite thick compared to that from a drum type chipper.