Technical Specifications
- Weight: 5–80 tons (customizable)
- Diameter: ≥1.8 meters (customizable)
- Materials: ZG310-570, ZG35CrMo, ZG42CrMo, ZG45
- Surface Hardness: ≥HB170
- Heat Treatment: Normalizing, tempering, quenching + tempering
- NDT Methods: UT (ultrasonic), MT (magnetic particle)
- Application: Cement rotary kilns, lime kilns, activated carbon kilns, rotary dryers
- Customization: Yes, according to customer drawings
Rotary Kiln Riding Ring for Cement & Lime Kilns
The rotary kiln tyre (also called the riding ring, rolling ring, or kiln tire) is one of the most important components of a rotary kiln. It is a large annular steel casting mounted on the kiln shell. Think of it as the “track” that the kiln rides on. It supports the entire weight of the rotating kiln—including the shell, refractory bricks, internal devices, and materials—and transfers it to the support rollers below.
The tyre does more than just carry weight. It also strengthens the kiln shell and helps keep it round. Without a strong, properly fitted tyre, the kiln shell could deform, the refractory lining could fail, and the whole production line could stop.
AGICO has been manufacturing rotary kiln tyres for over 20 years. We supply high-quality tyres for cement plants, lime kilns, and other rotary processing systems worldwide. Our rotary kiln tyres are made from high-strength cast steel and are custom-made according to your drawings and specifications.
Rotary Kiln Tyre Working Principle
The rotary kiln tyre is mounted on the kiln cylinder. As the kiln rotates, the tyre rotates with it. The tire sits on top of support rollers and rotates against them. The support rollers bear the full weight of the rotating kiln — which can be hundreds of tons.
Think of it like a train wheel on a track. The tyre is the wheel, and the support rollers are the track. The tyre transfers all the weight of the kiln cylinder — including the refractory bricks, internal devices, and materials — to the support rollers. This allows the kiln to rotate smoothly and stay in alignment.
Thermal Expansion:
During operation, the kiln shell can reach 300–400°C while the tyre runs cooler. A small gap is left between the tyre and the shell to allow for thermal expansion. This gap — called “creep” or “clearance” — is normal and necessary. Without it, the tyre could crack from thermal stress. When the shell expands from heat, the gap closes. This allows the tyre to “float” on the shell and prevents damage.
Types of Kiln Tyre Rings – By Cross-Section Shape
There are two main types of rotary kiln tires, classified by their cross-sectional shape:
Rectangular (Solid) Tyre
The cross-section is a solid rectangle. It has a simple shape, which makes casting easier and reduces the risk of cracks. Its service life is generally longer than the box type, and it is widely used in rotary kilns. However, it has less rigidity than the box type and uses more material.
Get a QuoteBox (Hollow) Tyre
The cross-section is a hollow box. It has higher rigidity and better thermal conditions and uses less material than the solid type. However, the shape is more complex, and cracks are more likely to form during casting.
Get a QuoteAGICO can produce both types according to your requirements. The rectangular type is more common and recommended for most cement kiln applications.
Rotary Kiln Tyre Materials
The material of the kiln tyre determines its strength, toughness, and service life. Because the tyre bears hundreds of tons of weight and operates at high temperatures, it must have both high strength and good toughness.
AGICO offers the following main material options:
| Material | Strength | Toughness | Best for |
|---|---|---|---|
| ZG310-570 | High | Medium | Standard cement kilns |
| ZG35CrMo | Very High | High | Heavy-duty kilns, high-temperature conditions |
| ZG42CrMo | Very High | High | Heavy-duty kilns, best wear resistance |
| ZG45 | High | Medium | General applications, good cost performance |
How to Choose the Right Material
- For standard cement kilns: ZG310-570 is sufficient. It offers good strength at a reasonable cost.
- For heavy-duty or high-temperature kilns: Choose ZG35CrMo or ZG42CrMo. These alloy steels offer higher strength and better heat resistance.
- For general applications with good cost performance: ZG45 is a good choice.
AGICO can also cast tires with customer-specified materials. Just provide your requirements.
Rotary Kiln Tire Mounting – The Floating Design
AGICO uses the floating (loose) tire design, which is the industry standard for modern rotary kilns. In this design, the tyre sits on floating pads that are not welded to the shell. This allows the tyre to “float” and move slightly, creating a small gap (creep) between the tyre and shell for thermal expansion.
The floating pads serve two important functions:
- They protect the shell from direct contact with the tyre
- They form natural ventilation channels between the tyre and shell, helping to cool the shell
Axial stops (small metal tabs welded to the shell) keep the tyre from sliding sideways along the shell while still allowing it to move freely during thermal expansion.
Note: Other mounting methods exist, but they are rarely used in modern cement kilns. Fixed mountings cannot accommodate thermal expansion. Splined systems are complex and typically found only in specialized high-end equipment.
Advantages of AGICO Cement Rotary Kiln Part Tyre
High Strength and Good Durability
AGICO tyres are made of high-quality cast steel (ZG310-570, ZG35CrMo, ZG42CrMo). These materials provide high tensile strength and toughness, so the tyre can bear heavy loads without cracking.
Advanced Heat Treatment – Even Hardness, Long Life
AGICO uses normalizing and tempering (or quenching and tempering) heat treatment. The surface hardness of the working part is at least HB170. This ensures the tyre has uniform hardness, good wear resistance, and high toughness. It can adapt to various harsh working environments.
Precision Machining – Smooth Surface, Accurate Fit
We use large vertical lathes and other advanced equipment for precision machining. The surface is smooth, and the machining deviation is small. This ensures the tyre fits the kiln shell properly and rotates smoothly.
Complete Inspection – No Hidden Defects
Every tyre undergoes non-destructive testing (ultrasonic testing, magnetic particle testing) to check for cracks, inclusions, and pores. We also use a German spectrometer to test the chemical composition of the molten steel. Each tyre comes with a full material test report.
Custom-made according to your drawings
AGICO can produce kiln tyres of various sizes, weights, and materials according to customer drawings. Just provide us with detailed CAD or PDF drawings, and we will do the rest.
One-stop service – from design to delivery
AGICO provides a complete service: casting simulation, pattern making, pouring, heat treatment, machining, testing, and packaging. We handle everything under one roof, so you don’t need to deal with multiple suppliers.
Manufacturing Process
AGICO follows a strict manufacturing process to ensure every kiln tyre meets the highest quality standards:
- Drawing confirmation
- CAE casting simulation
- Wooden pattern making
- Pit sand mold preparation
- Smelting in electric arc furnace
- Molten steel testing (spectrometer)
- Pouring
- Sand cleaning
- Rough machining
- Non-destructive testing (UT, MT)
- Defect repair (if needed)
- Heat treatment (normalizing, tempering, Q&T)
- Finishing machining (CNC)
- Final inspection
- Packaging and delivery
Applications
- Cement plants – Rotary cement kilns
- Lime plants – Lime rotary kilns
- Chemical industry – Activated carbon rotary kilns
- Metallurgical industry – Various rotary kilns
- Other rotary equipment – Rotary dryers, rotary coolers
Common Problems & How AGICO Solves Them
| Problem | Why It Happens | AGICO Solution |
|---|---|---|
| Surface spalling | Excessive contact stress causes surface fatigue | High-quality alloy steel + proper hardness control |
| Radial cracks | Thermal fatigue or casting stress release | CAE simulation to prevent defects + UT/MT testing before delivery |
| Excessive creep | Worn backing plates, loss of shell constraint | Design the tyre and gap according to your specific kiln conditions |
| Ovality (loss of roundness) | Incorrect tyre clearance | Precision machining for accurate fit + proper gap design |
FAQ about Rotary Kiln Tyre
Q1: What is the difference between kiln tyre and riding ring?
A: They are the same part. “Kiln tyre” and “riding ring” are two names for the same component.
Q2: Why is there a gap between the tyre and the kiln shell?
A: During operation, the kiln shell expands from the heat while the tyre stays cooler. The gap allows for this thermal expansion. Without it, the tyre could crack from the stress. This gap is called “creep” and is a normal part of kiln operation.
Q3: What is the service life of an AGICO kiln tyre?
A: With proper maintenance, AGICO kiln tyres typically last 15–25 years. The actual life depends on operating conditions, temperature, and load.
Q4: What materials are AGICO kiln tyres made of?
A: We use ZG310-570, ZG35CrMo, ZG42CrMo, and ZG45 cast steel. We can also use customer-specified materials.
Q5: What is the hardness requirement for a kiln tyre?
A: The surface hardness of the working part is typically HB 170–240. AGICO tyres guarantee a surface hardness of not less than HB170.
Q6: What is the difference between rectangular and box tyres?
A: Rectangular tyres have a solid cross-section—simpler to cast, longer life, but less rigid. Box tyres have a hollow cross-section—higher rigidity, less material, but harder to cast.
Q7: Can AGICO produce a kiln tyre according to my drawing?
A: Yes. AGICO accepts custom orders based on customer drawings. Just provide us with detailed CAD or PDF drawings.
Q8: What is the lead time for a kiln tyre?
A: The lead time depends on the size and specifications. Typically 45–90 days. Contact us for a specific quote.
Q9: Do you supply other rotary kiln spare parts?
A: Yes. AGICO supplies a complete range of rotary kiln spare parts, including support rollers, thrust rollers, girth gears, kiln shells, and sealing devices.
