A plant replaced metallic arrowhead nozzles in its bed with reaction bonded silicon carbide.
Bed nozzles sit in hot, moving sand and ash for the whole campaign.
Metal arrowheads erode there, ceramic ones are built for it
In this case a plant with a fluidized bed replaced its metallic arrowhead nozzles with arrowheads cast by Blasch from InVinCer reaction bonded silicon carbide. Blasch summarized the result as a clear gain in service life over the metal parts the plant had used before.
Arrowheads are the nozzle caps on the air distribution grid of a fluidized bed. Combustion air leaves through them sideways and keeps the bed moving. The same bed material that they fluidize grinds against them, at furnace temperature, every hour the boiler runs.
Fabricated and cast metal arrowheads wear thin, lose their outlet shape and start to distribute air unevenly. Worn nozzles also let bed material fall back into the air box. Each change means an outage and work inside the furnace on the grid.
A fluidized bed is only as even as its nozzles, so a nozzle that keeps its outlet shape keeps the whole bed running the way it was designed.
The plant switched to arrowheads in InVinCer RB, a reaction bonded silicon carbide that Blasch uses for parts under combined abrasion and heat. The arrowheads are cast close to final shape with the Blasch process, so outlet bores and seats need no machining.
Blasch bubble caps, arrowheads and tuyeres are co-patented designs. They are made for both circulating and bubbling fluidized beds, can be welded or bolted to the grid, are designed against plugging and can be walked on during outages.
Bed nozzles, bubble caps, arrowheads and tuyeres in silicon carbide grades.
InVinCer RB, the grade used for these arrowheads.
Wear and heat parts for boilers that burn coal, biomass and other abrasive fuels.
Yes. The arrowheads are cast to the dimensions of the existing nozzles and can be welded or bolted to the grid.
It combines high hardness with resistance to heat and thermal shock, which is the load case of a nozzle sitting in a hot, moving bed.
Both. Blasch makes bed nozzles, bubble caps, arrowheads and tuyeres for circulating and bubbling fluidized beds.
Send the nozzle type, the grid layout and the fuel. A Blasch engineer looks at which grade and shape fit your bed.
