Silicon carbide spray nozzles for desulfurization absorbers, gas cooling and reagent injection.
SO2 removal depends on the spray pattern in the absorber.
The pattern depends on an orifice that slurry wears every hour.
FGD spray nozzles resist slurry erosion when the orifice and the swirl surfaces are cast from a dense, abrasion resistant silicon carbide, because limestone slurry wears softer materials until the spray angle and droplet size drift. Blasch casts FGD and ceramic spray nozzles in NITRON nitride bonded, OXYTRON oxide bonded and InVinCer reaction bonded silicon carbide, as spiral, tangential hollow cone and special designs. They come threaded, flanged or combined with a metal assembly to fit the existing spray headers.
Spiral nozzles: the slurry leaves along a cast spiral that breaks it into concentric cone sheets, with an open path that resists plugging.
Tangential and hollow cone nozzles: the slurry enters a swirl chamber from the side and leaves as a hollow cone, with the inlet and chamber cast as one piece.
Special nozzles: internal vanes and complex bores are formed in the mold, not machined, so even small series keep the same geometry.
Threaded and flanged ends: threads and flanges are cast in, so the nozzle bolts or screws onto the header like the part it replaces.
An FGD absorber removes SO2 only as well as its nozzles spread the slurry, so a worn orifice shows up in the stack readings before anyone sees it in the header.
Limestone slurry in a wet scrubber carries hard particles at high velocity through a small orifice. The wear concentrates where the flow is fastest: at the outlet edge, on the spiral and in the swirl chamber.
As the orifice grows, flow rises and pressure falls. Droplets get larger, the spray angle narrows and parts of the absorber cross section lose coverage. The result is lower SO2 removal at the same pump power, or more pump power for the same removal.
That is why FGD nozzles are often replaced on a fixed schedule. A material that wears more slowly stretches that interval and keeps the spray closer to its design until the next outage.
| Grade | Bond | Strength in FGD service |
|---|---|---|
| NITRON | nitride bonded silicon carbide | abrasion resistance and toughness for spiral and cone nozzles |
| OXYTRON | oxide bonded silicon carbide | thermal shock resistance where hot gas meets the spray |
| InVinCer RB | reaction bonded silicon carbide | dense, very hard wear surfaces |
The same nozzles run in gas cooling, NOx reduction, particulate removal and other injection duties, wherever an abrasive or corrosive liquid has to be sprayed into hot gas. Nitride bonded silicon carbide
Blasch nozzles are cast to the connection of the nozzle in service, threaded, flanged or held in a metal assembly. A drawing is not required: the current nozzle or its dimensions and the spray data are enough.
The absorber is not the only place in the flue gas path where slurry and ash wear steel.
Ceramic linings for scrubber and cyclone sections that see the same abrasive flow.
Silicon carbide tips and linings for the burners of the boiler upstream of the absorber.
Precast abrasion resistant parts as an alternative to metal shapes and cast refractory in cement production.
Silicon carbide is far harder than the limestone particles in the slurry and resists the absorber chemistry, so the orifice keeps its size longer.
Yes. The nozzle is cast to the geometry and connection of your current part. Send the nozzle or its dimensions and the spray data.
Yes. Spiral and tangential hollow cone designs are cast with their internal shape in one piece.
No. They are used wherever gas is scrubbed, cooled or treated with an injected liquid, in power, cement and other heavy industries.
Send the nozzle type, its dimensions and the slurry conditions. A Blasch engineer proposes a grade and the connection.
