Process Engineering

Grenzebach is your partner for mechanical and thermal process engineering. For more information, please, contact:

Sectional cooler

Cooling of high-temperature bulk materials (up to 1,400°C) of all kinds in an indirect water cooled rotary tube. Extremely high throughputs are handled safely and reliably.


The Sectional Cooler is an indirect water-cooled cooling device for free-flowing bulk materials (see diagram, items 1,2 and 3). Externally, it is designed as a rotary drum, with the interior being divided into several sections (sectors / diagram, item 4). During the rotational movement cooling water flows through the walls between the sections and through the double-walled drum jacket (diagram, items 5 and 6) in opposite direction to the product flow. Various types of internals in the product chamber ensure proper conveying and mixing of the product.

Design features

The cooling water is supplied to the cooler through a central hollow shaft (diagram, item 7). Having passed through the water channels, the heated water is discharged from the apparatus at zero pressure through a second central hollow shaft (diagram, item 8). Due to this zero-pressure discharge, the sectional cooler is an unpressurised system, i.e. no pressure apparatus as per AD 2000 Code of Practice or TRD (German Boiler Code), and this offers advantages in terms of operation, maintenance, and licensing. Smaller units of this type of apparatus are supported at the ends of the central shaft. Larger units have a tread roller support as it is typical of rotary drums (diagram, item 9). The drive is via chain or girth gear (diagram, item 10). The rotor is closed off at one end by a product feed housing and by a discharge housing at the opposite end (diagram, items 11 and 12). Special seals arranged between these stationary housings and the rotating drum jacket provide for a suitable air seal.


The Sectional Cooler is particularly suitable for such cooling tasks where, for instance, in a convective cooling process ultrafine product would be discharged together with the cooling air flow. Here, the indirect Sectional Cooler offers the advantage of working without any product losses (caused by entrained dust) so that no dedusting system is necessary. Moreover, this cooler can be built in relatively compact dimensions. The sturdy design of the cooling chamber and the geometry of the apparatus also make it suitable for cooling solids containing coarse particles or even agglomerates. The cooling chamber can be inertised (for instance with nitrogen or carbon dioxide, or even as a result of air-tight sealing alone) for cooling reactive products. Another outstanding feature is the good cooling capacity, which allows very high inlet temperatures and high throughput rates to be handled safely. Some 250 Sectional Coolers for a wide range of applications have been supplied since the mid 1960s.

Typical Applications

The Sectional Cooler has proved tried and tested for fine, non-sticking industrial products (such as sodium tripoly phosphate "STPP", kaolin, converter dust), production residues with high inlet temperatures (such as zinc blende, roasted product and pyrites cinders) as well as for reactive products that must be processed in an inert atmosphere (such as petroleum coke). Moreover, soda prills, soda, zeolite, activated carbon, calcium carbonate and many other products are dried in Sectional Coolers.

Limits of Application

Grenzebach BSH builds Sectional Coolers with cooling surfaces of 8 to 1,000 m², removing heat quantities of 25 to 25,000 kW. Product temperatures up to 1,400 °C can be handled.