Feuerfeste Verankerungen are critical components that ensure the stability and durability of the refractory linings within cement plants. Acting like a “skeleton,” they secure refractory materials—such as castables—to the equipment’s outer shell, enabling them to withstand high temperatures, chemical corrosion, and mechanical stress.
Key performance requirements for anchors include:
Effectively securing the refractory lining
Resisting thermal stress, mechanical stress, and thermal expansion
Preventing refractory materials from spalling or developing defects
Enhancing the lining’s resistance to static loads, thermal stress, and vibration
The application of anchors in cement plants spans nearly all critical thermal processing equipment; their proper selection directly impacts the stable operational cycle of the equipment:
Rotary Kiln Systems: Support the lining and are widely used in high-stress zones such as the kiln inlet, kiln hood, and burner areas.
Preheaters and Calciner Furnaces: Used in high-temperature sections—such as discharge chutes and conical sections—to secure castables and other monolithic refractory materials.
Grate Coolers: Employed in wear-prone areas, such as retaining walls; specially designed metal anchor studs are often utilized here to enhance the stability of precast refractory blocks.
Tertiary Air Ducts: Used to secure wear-resistant linings in sections subjected to erosion by high-temperature, dust-laden airflow.
Discharge Chutes and Elbows: At pipe bends characterized by high airflow velocities and heavy dust loads, anchors effectively prevent the lining from eroding or spalling.
A correct construction process is the decisive factor in ensuring the performance of anchors. Based on industry best practices, the following are key steps and considerations:
Pre-construction Preparation: Before casting, it is essential to complete the welding of anchors, the installation of calcium silicate boards (for thermal insulation), and the erection of formwork.
Anchor Welding: Prior to welding, remove any surface dust or debris; ensure the weld bead is full and robust (requiring welding on all four sides); after welding, tap the anchor with a hammer to verify its firmness.
Thermal Expansion Compensation: Welded anchors must undergo thermal expansion treatment—such as applying bituminous paint, wrapping with tape, or sheathing with plastic tubing—to prevent high-temperature expansion from damaging the surrounding castable refractory material. Expansion Joint Provision: A clearance gap (≤ 50 mm × 50 mm) must be left in the calcium silicate board surrounding the anchors. This serves a dual purpose: it provides thermal insulation and prevents hot gases—should the refractory castable crack—from burning through the anchors.
Quality Inspection: Prior to casting, the type, dimensions, layout, and weld quality of the anchors must be verified. In particular, it is essential to confirm that the metal anchors have undergone the necessary expansion compensation treatment.