What is a rotary kiln? An ultimate beginner’s guide to how to select a rotary kiln. Zhejiang Tongli

A rotary kiln is a common piece of industrial equipment used to process and transform materials at high temperatures. It is a long, cylindrical vessel, usually placed horizontally and mounted at an inclination. The material enters the rotary kiln through the kiln tail and then gradually moves along the axial direction inside the kiln before it is finally discharged through the kiln head. The working principle of the rotary kiln is based on the thermal treatment and transformation of materials at high temperatures. By heating the material inside the rotary kiln, different treatment effects such as drying, calcining, roasting, incineration, smelting, gasification, etc. can be achieved, depending on the needs of the application and the process requirements.

What are the types of rotary kiln?

 According to the feeding method: According to whether the materials entering the kiln contain water, they are divided into dry kilns and wet kilns. Wet kilns can be divided into inflow method and injection method.

 According to the length-to-diameter ratio: The length-to-diameter ratio is the basis for dividing long kilns and short kilns. Generally, dry kilns have fewer working sections and the length-to-diameter ratio is less than 16, which is a short kiln. Wet kilns are generally long kilns. The aspect ratio is between 30 and 40. The drying process in the spray kiln is shortened and is somewhere in between.

 According to kiln type: According to the geometric shape of the cylinder, it is divided into straight barrel kiln, cold end expanded kiln, hot end expanded kiln, firing zone expanded kiln and both ends expanded kiln.

 According to the cooling method of the material: When multiple cooling cylinders are fixed at the hot end of the cylinder, it is called a kiln with a multi-cylinder cooler to distinguish it from a kiln with a separate cooler.

 Rotary kiln based on the transmission type can be separated into girth gear-pinion drive and friction drive rotary kiln, Tongli is an expert in the filed of manufacturing both of them.

 Rotary kiln can also be divided into incineration rotary kiln and material processing rotary kiln based on its function, a material processing rotary kiln serves the function of processing material whereas the incineration rotary kiln is mainly used for waste material disposal.

 According to the heating method, it can be divided into internal heating kiln and external heating kiln. Most kilns are internally heated kilns. In non-ferrous metallurgy and chemical plants, when the materials being processed are highly toxic or when high flue gas concentration and high product purity are required, external heating rotary kilns are also used, using electric heating wires or heavy oil to indirectly heat the materials outside the cylinder. Its diameter is generally small, so it is called a rotary tube.