A ceramic alternative to cast iron inserts at the tubesheet of clinker cooler heat exchangers, from International Cement Review 2014.
Clinker dust turns into the tubes at full speed.
The first inches of each tube take all of it.
This International Cement Review article presents a Blasch ceramic insert as an alternative to Ni-Hard cast iron inserts in the tubesheets of clinker cooler heat exchangers. These exchangers sit downstream of the clinker cooler and ahead of the kiln baghouse, and their tube inlets wear from abrasive clinker dust. A thin walled silicon carbide insert absorbs that wear, protects the tube to tubesheet weld and keeps the exchanger in service.
Once dust erodes through the tube to tubesheet weld, dirty gas leaks into the clean air side, and the repair means cutting tubes out.
The gas leaving the clinker cooler carries hot, abrasive clinker dust. In a gas to air heat exchanger it turns into the tubes at the tubesheet. That turn concentrates wear on the tube inlet and the weld.
Cast iron inserts such as Ni-Hard have been the usual protection, and they wear as well.
Blasch clinker cooler wear inserts are cast with thin walls, flanges and tight tolerances. They sit in the tube inlet, protect the weld and the tube surface and take the abrasion from the hot clinker gas as it enters. Thin walls keep the flow area, so the pressure drop stays low.
The inserts are made in abrasion resistant silicon carbides such as oxide bonded silicon carbide (OXYTRON). Blasch states that they can also seal tubes that already have holes, so the exchanger can stay on line until the next planned stop.
The same design is used in tubular air preheaters of power and industrial boilers, see air heater inserts.
If tubes are plugged or cut out at every shutdown, the inlet is the place to protect. More wear parts for the plant are on cement and heavy industry, and the erosion topic in general on All-Round Ceramic Protection.
Downstream of the clinker cooler and ahead of the kiln baghouse filter, where it cools the exhaust gas.
Silicon carbide resists the abrasion of clinker dust better than metal, so the insert keeps its shape and protects the weld for longer.
Tube outside and inside diameter, tube length at the inlet, tubesheet thickness and the number of tubes.
Send tube size and count and what the inlets look like today. A Blasch engineer sizes the insert and the material.
