Tunnel Kiln vs Shuttle Kiln: The Pros & Cons

If you're looking for an industrial kiln capable of firing products in large volumes, there are two types of kiln that you can choose from: a tunnel kiln or shuttle kiln. In this article we examine how each type works, and the comparative advantages of each.
Shuttle kilns are versatile and are used in many industries, as they offer a good degree of precise temperature and timing control.

In factories, they're often combined with on-rail kiln cars that can ferry a large batch of product into the kiln. The 'shuttle' part of their name comes from the idea that you can simply shuttle kiln cars in and out of the kiln once the firing is completed.

Tunnel kilns work differently. Unfired pieces are loaded onto kiln cars and are slowly pushed through a long-heated chamber. This gradually heats the material until it is fired in the central part of the chamber.

They are commonly used to make mass-produced, high volume products such as heavy clay bricks and tiles, sanitary ware, tableware and many other products. Due to their sheer size, tunnel kilns are often housed in their own building.

What Are The Advantages & Disadvantages Of Using Each?

Shuttle Kilns

Shuttle kilns, also known as batch kilns or intermittent kilns, should be your first choice if you're running a business specialising in the rapid production of artisan pottery, tableware, sanitary or cladding tiles, and heavy clay products. They can be designed with capacities from 1m³ up to 400 m³. This means that a commissioned shuttle kiln can be adapted to the precise volume of work that you need to process and scaled up as appropriate with the addition of further shuttle kilns as capacity increases. They're typically less energy-efficient than a tunnel kiln; however, they offer more flexibility for both product and firing cycles.

We often recommend a shuttle kiln to growing businesses to allow them to build up capacity until volume necessitates an investment in a tunnel kiln.

When it comes to smaller pieces and diverse workloads, shuttle kilns are extremely flexible and can be reprogrammed with each batch to suit the needs of a specific type of product. The multiple control zone structure of the combustion system means that a uniform set temperature is applied evenly to all the pieces in one batch of products. Strict incremental increases in temperature can also be provided by this system, allowing for enhanced precision.

However, shuttle kilns probably aren't the best choice for high volume manufacturing. It may also prove more efficient and economical to use a tunnel kiln if you have to fire a constant flow of products over a long period of time. Shuttle kilns are better for smaller quantities of varied product mixes. However the processing time is longer than tunnel kilns, as the operative will need to wait until the kiln has completed its firing cycle and cooling cycle in order to unload the product.

Tunnel Kilns

A tunnel kiln should be used when you're producing a constant, high-volume production line. The variable cycle time of tunnel kilns makes them ideal for integration into a continuous and/or automated production line. Tunnel kilns are low maintenance and require less manual labour to operate, freeing up employees. They are generally maintained on an annual or bi-annual basis during shutdown periods.

With a tunnel kiln, the price per piece investment cost in terms of energy and equipment are also lower for high volume production.

The capital investment to build a tunnel kiln is higher than that of shuttle kilns. Please be aware that you'll also require a larger building footprint to accommodate the tunnel kiln and any loading/unloading tracks.

Bespoke Kilns From Therser

At Therser we design, manufacture, and build furnaces and kilns to suit any requirements. If you’d like to find out more about tunnel or shuttle kilns, and for advice on the type of kiln required for your product and process, please call or email our technical sales team today.