Screw heat exchanger

Screw heat exchanger

We offer specialized products for each particular field of application related thermal process technology and do cover the entire process portfolio: cooling off bulk-solids like for e.g. ashes, cement raw meal, drying of sludges or pastures and heating off for e.g. petroleum coke for the anode production lines of the aluminium-industry.
The application areas of screw heat exchangers is from power stations, cement, aluminium and the chemical industry through to the food industry.
The temperature range of the screw heat exchanges extends from 1200°C (cooling) to over 220°C (heating) with heat transfer media temperatures above 350°C. With KOELLEMANN screw heat exchangers, bulk materials receive the perfect thermal treatment.

KOELLEMANN self-cleaning screw heat exchangers differ with their special design from the standard models available on the world market. The proven hollow flight principle in combination with the well-proven self-cleaning system is key to the success of our product.

As some bulk products tend to form adhesions and tend to be bridging, they often build an insulating layer on the hollow flights. Depending on the condition of your bulk product, sludge or paste, the self-cleaning provides a proven, reliable option for the screw heat exchanger, which ensures uniformly clean hollow flight surfaces. As these constitute the main surfaces for heat transfer, efficient operation can thus be ensured.

By using a special geometry, the gap in-between the hollow flights is nearly eliminated and a high relative speed is generated between the surfaces of the screw shafts. This in turn has a cleaning effect; it removes adhering bulk materials and results in greater efficiency. Only our self-cleaning technology allows the use of screw heat exchangers when processing adhesive and pasty bulk materials.

We can offer single, double and multiple-shaft screw heat exchanger in a wide range of trough designs in the form of cooling or heating screws. We also provide screw heat exchangers in different styles for various types of applications.

Available trough-shapes for screw heat exchangers


Pipe Trough screw heat exchanger:

– Cost-efficient at high process room pressure


 U-trough screw heat exchanger:

– Easy to maintain

– Small space required for replacement of shafts

– Space for additional aspiration air


 Ꞷ-Trough screw heat exchanger

– High capacity density

– Application in case of problematic conveying characteristics


ꞶꞶ-Trough screw heat exchanger

– Maximum thermal capacity and compact design

Screw heat exchanger data

– Forced mechanical cleaning
– High shear forces
– Clean surfaces ensure efficient energy transport
– Speed ratio of the shafts 2:1 (same rotational direction)
– Conveyed material consistence up to Vaseline-like/silicone



KOELLEMANN preheaters are used to heat up petroleum coke. Petroleum coke is a residue formed as a by-product of petroleum refining and is made of almost pure carbon. KOELLEMANN preheaters perform the heating process and heat the product from at least 0°C to approx. 200°C. The heated petroleum coke is then mixed with hot pitch in a kneader. The paste formed is then pressed into a block shape. These blocks are then baked and represent the anode, which is used in the Hall-Héroult process (electrolysis) for the reduction of aluminium.

Heating screw conveyors

Heating screw conveyors

Heating screw conveyors are typically used for heating, drying or heat treatment of all types of bulk products such as petroleum coke, pasty media, dusts, pastes or slurries. Our heating screw conveyors introduce a defined quantity of heat into the product to heat or melt it, to evaporate liquid components or to start or stop a reaction.

The product range extends from heating screw conveyors and dryers with a throughput rate of a few kg/h up to 60t/h – on request, the delivery is completed by including especially adapted piping with modular insulation, which enables connection to a central inlet and outlet point.

All necessary valves, flow meters and temperature measurement devices are optionally already installed upon delivery as part of the scope of supply.

To integrate the heating screw conveyors into the planning of your plant, you can use a variety of heat sources such as heat transfer oils, various steam conditioning systems and purely electric heating.


Heating screw conveyors data:

– Temperatures up to 450°C

– Use of proven and tested hollow flights

– Single or multiple shaft version

– Safe and reliable separation of heat transfer medium and bulk material

– Suitable for all bulk materials

– Optional modular insulation

– Optional with piping, fittings and valves


Cooling screw conveyors

Cooling screw conveyors

KOELLEMANN Cooling Screw Conveyors have their field of application within the cooling of bulk-solids, pastures as well as sludges and slurries. For each special application and bulk-solid condition, we offer a custom-tailored variation. KOELLEMANN Cooling Screw Conveyors represent the ideal solution for any application, where gentle handling and rigid separation of the bulk-solid and coolant is mandatory. KOELLEMANN Cooling Screw Conveyors are universally usable for bed-ashes, flue-dust, sewage-slurries, cements, salts, plastics, pyrolysis residues, cyanide or pastures in every kind of condition.

The application and temperature range of the cooling screw conveyors extends up to 1,200°C. Through active cooling of all surfaces touched by the product, long service life and low material impact can be achieved.


Cooling screw conveyors data:

– Suitable for temperatures up to 1200°C

– Single or multiple shaft version

– Suitable for all bulk materials

– Use of proven and tested hollow flights

– On request, with piping, fittings and valves

– Safe and reliable separation of heat transfer medium and bulk material

Typical applications for cooling screws:

– Cooling screws for cooling cement raw meal from 900°C to 150°C

– Cooling screws for cooling pyrolysis residues from 560°C to 60°C

– Cooling screws for cooling ashes from 850°C to 150°C

– Cooling screws for cooling activated coal granule from 700°C to 40°C

– Cooling screws for cooling activated coal granule from 700°C to 40°C

– Cooling screws for cooling sludge granule from 120°C to 32°C

– Cooling screws for cooling metal oxides from 500°C auf 50°C

– Cooling screws for cooling plastics from 120°C to 40°C

– Cooling caustic soda flakes from 85°C to 60°C

Your System Supplier for Complex Solutions

Whether it is components, systems or complete turnkey solutions “as a service”: Let our chlor-alkali and bulk material experts advise you on your challenges.