Tube end inserts for the heat exchanger behind the clinker cooler, as an alternative to cast iron inserts.
Clinker dust wears the tube ends of the cooler heat exchanger first.
Silicon carbide inserts take that wear.
In the heat exchanger that cools the exhaust air of a clinker cooler, silicon carbide tube end inserts extend the life of the tubes and the tubesheet. They sit in the tube inlets, take the abrasion from clinker dust and protect the tube end and the weld. Blasch designed them as an alternative to Ni-Hard cast iron inserts and casts them in alkali and abrasion resistant OXYTRON and NITRON silicon carbide.
The heat exchanger sits downstream of the clinker cooler and ahead of the kiln baghouse filter. It cools the exhaust air before it reaches the filter, and that air still carries fine, hard clinker dust.
The dust hits hardest where the air turns into the tubes. Without protection, the tube ends and the welds at the tubesheet wear first. A common protection there is an insert of Ni-Hard cast iron in each tube end. Blasch developed a silicon carbide insert to replace it and to extend the life of the exchanger.
The tube end insert is the smallest part of the heat exchanger, and it decides how long the tubes behind it last.
The inserts are cast to the tube, with thin walls, flanges and tight tolerances, in grades chosen for cement plant conditions.
Silicon carbide holds up to the hard, fine clinker dust that the cooler exhaust air carries into the tubes.
OXYTRON and NITRON are chosen for resistance to alkali attack as well as to wear.
The thin cast wall keeps the tube opening wide, so the exchanger loses little flow area.
Where tube ends already have holes, an insert can often close them and keep the exchanger running until the outage.
Blasch described the insert and its savings in the article Extended Heat Exchanger Life, published in International Cement Review in February 2014. The article is in the technical library.
Clinker and cement dust wear more than the cooler. Abrasion resistant precast ceramic parts are an alternative to expensive metal shapes or cast refractory across cement equipment, as the article All-Round Ceramic Protection explains. Silicon carbide dust collector components follow the same idea for multicyclones. More on parts for heavy industrial processing and on nitride bonded silicon carbide.
The same insert principle protects tube ends in boilers that burn abrasive fuels: see air heater inserts and the overview of all ferrules and tube inserts.
They work on the same principle: a thin silicon carbide sleeve in the tube end. Grade and geometry are chosen for clinker dust and the conditions of the cooler exhaust air.
That is what they were developed for. The fit is checked against the tube dimensions of your exchanger.
Tube outside and inside diameter, the length of tube to protect, the insert you use today and how it is fixed. No drawing is needed.
Send the tube size and the insert you run today. A Blasch engineer designs the silicon carbide insert for your exchanger.
