Industrial engineers and anyone in the business of manufacturing understand the importance of consistency. Quality control is everything in these sectors. One of the biggest quality control hurdles in industrial manufacturing is temperature. How do you sustain a specific temperature? If you can’t even do that, how can you create a reliable temperature profile that heats your product to certain key temperatures at the right time and for the right duration?
Roller kilns are your answer. They are fine-tuned for temperature control. Better yet, they use less fuel on average than a standard kiln or furnace due to their continuous operation and long shape that cuts down on wasted heat.
What Are Roller Kilns?
Have you ever seen a pizza cooked in a commercial conveyor oven? You put the raw pizza in one end where it slowly rolls through the oven where it arrives on the other end, fully cooked and ready to be boxed up. The same idea is applied in a roller kiln, which is why it’s sometimes referred to as a “tunnel kiln”. The material being fired is fed through one end, it rolls through the tunnel oven, and eventually comes out of the other side completely fired.
There are clear benefits to this method of firing. For one, roller kilns (or “roller hearth kilns”) are much more energy-efficient due to the ability to multilaterally heat your product (less waste heat is produced). Because a roller kiln is long it gives the operator the ability to create a “temperature profile” wherein the hottest temperature is in the middle of the kiln and the amount of heat decreases at either end. This gradual heating gives you complete temperature control. Best of all, roller kilns are fast.
Which Industries Use Roller Kilns?
Many industries benefit from the use of roller kilns. Because a roller kiln production process is energy efficient, fast, and extremely controllable, it is simple to fit this setup into a mass production line. These are just a few of the industries taking advantage of the roller kiln:
⦁ Advanced and technical ceramics
⦁ “Sanitaryware” like labware and medical ware
⦁ Tableware and general-use ceramics
⦁ Terra cotta
⦁ Abrasives, grinding media, powers, and pigments
⦁ Bulk firing
As you can see, roller kilns benefit any industry that relies on ceramics, either traditional or advanced. Your terracotta flower pots from the big box hardware store in your garden were more than likely fired on a roller kiln!
What Are Ceramic Rollers?
Roller kilns rely on a sequence of ribbed rollers to move product from one end of the oven to the other while in operation. These rollers must be made of a durable material that can withstand a constant high temperature while also withstanding the thermal shock produced when they leave their heat source and rapidly cool.
It makes sense that the rollers installed inside of a roller kiln would be made of ceramic. In most cases, the ceramic used is an "advanced ceramic" enhanced with a material such as alumina, silicon carbide, or fused silica. This fusion gives the ceramic better temperature resiliency, higher resistance to thermal shock, and a denser, hardier composition to better withstand general wear-and-tear.
Types of Industrial Ceramic Rollers
The three most popular types of industrial ceramic rollers are considered “advanced ceramics”, meaning they’ve been enhanced by other materials to amplify their natural properties. Let’s break down the three most popular types:
Alumina: enhanced by aluminum oxide (Al2O3), alumina is highly resistant to temperatures of up to 1,400C. It’s one of the most popular varieties of engineered ceramic on the market.
Silicon Carbide: also known as “carborundum", silicon carbide is a powdered concoction of both silicon and carbon. When used to enhance ceramic it resists temperatures of up to 1650C while making the ceramic operate almost like a metal; less brittle and much denser.
Fused Silica: made of super-heated silica grains, fused silica ceramic becomes a new material that is impervious to temperatures of up to 1,150 while being highly resistant to thermal shock and regular wear-and-tear.
Roller Kilns: Fast, Efficient, Highly Controllable
The manufacturing industry has known for some time that roller kilns are the way to go when you want to mass-produce a product under specific conditions. From medical supplies to home goods, the roller kiln is here to stay as the go-to method for firing ceramic in an industrial setting.
Thanks to advanced ceramics, industrial ceramic rollers are a perfect fit for the roller kiln. They won’t break easily; they’ll withstand the high temperatures of a kiln as well as the sudden drop in temperature that is normal during the firing process. As far as kilns go, the modern roller kiln is a jack-of-all-trades machine that will suit any industrial setting perfectly.