Rotary Kiln

Just as a heart must never stop beating, so a rotary kiln must never stop turning. Which is why our kilns – whether the two-pier Pyrorapid® or a classic three-pier kiln – are engineered to keep rotating, even in the most challenging of process conditions. So, you can relax with the guarantee of reliable, trouble-free operation, 24 hours a day, seven days a week.

All important kiln components are explained in detail on another page. Head over to the rotary kiln parts page to learn more.

Product Features

A kiln is just a kiln, right? They are all the same. If that’s your attitude, we suggest a rethink.

Product Features

When is a kiln not just a kiln?

A well-performing kiln does not just happen. It is the product of well-engineered and reliable components, mixed with an expert understanding of the cement-making process and long years of experience in the design, installation and support of rotary kilns around the world. Not many companies have all three. But we do. So, when is a kiln not just a kiln? When it’s a KHD kiln.

Product Features

Two pier or three?

We offer two-pier (Pyrorapid®) and three-pier kilns. Both are available in diameters of 3.6 m up to 6 m and for a similar range of capacities (three-pier kilns have a slightly higher top capacity). Choice will depend on your specific plant layout and process conditions, e.g., the use of alternative fuels, the quality of raw materials, or the space available.

With our experience and know-how of the pyroprocess and plant layout, our experts are well qualified to advise you on the best kiln design for your needs. Contact us today to speak with one of the experts.

Comparison of two-pier and three-pier kilns with the same diameter

Pre-calcination well suited ideally suited
Kiln inlet temperature well suited ideally suited
Statically defined system ideally suited well suited
Power consumption ideally suited well suited
Brick lining ideally suited well suited
Alternative fuels well suited ideally suited
Capacity well suited ideally suited
Sintering zone load ideally suited well suited

Kiln type selection depends on various factors including but not limited to alternative fuel use, raw material combustibility, clinker quality and overall pyroprocess.

You can rely on KHD

We have built and upgraded more than 500 kilns worldwide. Over the course of these installations, we have established ourselves as the technical leader not only in kiln manufacturing, but in the design, installation and optimization of the complete pyroprocess. In fact, it is that in-depth knowledge, gained from more than 16 decades in the cement industry, that sets us apart to be your reliable partner for any pyro-related project.

Key Benefits

If you can’t stand the heat, hang up your apron, get out of the kitchen – and leave the job to the professionals.

Key Benefits

Robust, reliable and worry free

  1. Revenue of high availability
  2. Revenue of low availability
  3. Total cost of ownership (OPEX & CAPEX)
  4. Investment

You rely on your kiln to do its job, day in, day out, without trouble. Because if it ever stopped turning, you risk serious deformation of the kiln shell and consequential damage to the major components – tires, roller bearings, girth gear, pinion, inlet and outlet. It’s a nightmare situation.

With our history of engineering excellence and reputation for quality, we provide kilns that bring peace of mind. But you don’t have to take our word for it: the performance and reliability of our kilns have been verified in real-world conditions for decades. It adds up to this simple offer: when it comes to kilns, we know what we are doing, and we lead the industry in doing it.

But even if the nightmare happens and you suffer severe deformation, with a KHD kiln, it’s not the end of the world. The girth gear/pinion transmission on KHD kilns allows high torques to be transmitted without risk of slippage (unlike the friction drives used in some other kilns). As a result, our kilns can be rotated in any condition. And through a careful procedure of turning and tilting the deformed kiln at intervals, we can to a certain degree even reduce shell deformation and straighten the kiln axis.

  1. Revenue of high availability
  2. Revenue of low availability
  3. Total cost of ownership (OPEX & CAPEX)
  4. Investment

Reliability based on proven components

How can we be sure our kilns will keep turning? Because our kiln components have demonstrated their reliability over and over again. Want to know more? We have an extra page all about these industry-standard kiln parts: head on over for the full story.

Key Benefits

Easy to operate, easy to maintain

So, the reactions that go on inside a kiln are pretty intense. You need at least an advanced degree in chemistry to understand them. But that is not true of operating or maintaining our kilns. In fact, we make both as simple and safe as possible – even with complex raw materials and fuels. No PhDs required.

For example, all critical components are easily accessible for inspection and maintenance: a simple daily walk-by is usually enough to notice anything that requires further attention. Lubrication points are also easily accessed.

During normal operation, the kiln operates with minimal attention, leaving your operators free to focus on other, more-complex tasks. Any adjustment that is needed, e.g., of the speed, can be easily made from the central control room. And because of its robust and safe design, when it comes to restarting the kiln after a stoppage, it can be done from nearly any position without special measures.

Performance Range & Data

Is our rotary kiln for you? Check out the performance data below. Or contact us to talk to an expert.

Performance Data

Diameter Range (0.2 m steps) 3.6 m to 6.0 m 3.6 m to 6.0 m
Dimension (length to diameter ratio) ~13 ~16
Capacity 1,500 tpd to 12,000 tpd 2,000 tpd to 14,000 tpd

Performance Range

3-pier kiln

2-pier kiln

The potential output of a kiln depends (amongst others) on clinker quality, fuels, combustibility of raw materials and the overall pyroprocess. However, there is a typical range for each size.

3-pier kiln

2-pier kiln

How it works

Complex chemistry but a simple process. Raw materials enter one end, are heated to 1500 °C+ along the way, and exit as clinker. Job done.

Clinker production in two- and three-pier kilns is based on the same chemical reactions and process zones, but the process zones have different lengths when comparing a traditional and a short kiln.


You have read what we have to say about our rotary kilns. But here is what really counts: our references of success projects.


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