Screw Heat Exchanger

For thermal process technology we offer specialized products for each particular field of application and do cover the entire process portfolio: cooling off bulk-solids like for e.g. bed-ashes, drying of sludges or pastures and heating off for e.g. petcoke for the anode-lines of the aluminium-industry.

Based on their design KÖLLEMANN Screw-Heat-Exchangers differ significantly from the standard models on the market, as they use the proven Hollow-Flight-Principle, which encapsulates serveral advantages. The decisive advantage is the achievable power density compared to the energy transfer via shaft tube and trough(housing). Due to the Hollow-Flight-Principle we achieve a multiple of transmission power, which results in a higher efficiency and leads to a smaller machine size which is required for a specific output. Applications in higher performance ranges can only be realized in the first place due to the hollow flight principle.

The temperature range of the KÖLLEMANN Screw-Heat-Exchangers reaches from cooling down from 1200°C up to heating to more than 200°C with heat-transfer-medium temperatures above 350°C.

The main asset is the significantly enhanced heat-exchanging surface, leading to lower thermal-stress on the screw-flight – especially during cooling-applications as well as forced heat-transfer-medium guidance inside the shaft.

KÖLLEMANN produces the Screw-Heat-Exchangers in accordance with standards such as AD2000 or ASME BPVC Sec.8 div.1 to ensure an maximum of safety during the handling of the heat-transfer-medium.

Following thermal processes can be realized with our screw-heat exchangers:

> Cooling of bulk solids and pasty substances of all kinds

Specialised cooling screw conveyor products are available for different application areas and bulk material formulations. It is suitable for all applications where not only careful handling of the bulk product is required but also strict separation of cooling medium and bulk product. KÖLLEMANN cooling screw conveyors can be used in applications by e.g. bottom ash, fly ash, sewage sludge, cement, salts, plastics, pyrolysis waste, cyanide, and pastes of all formulations.

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.
There are hardly any limits to their use – direct removal from the fluidised bed is just as easy for KÖLLEMANN cooling screw conveyors as their use in cooler cascades to gently control the temperature of large volume and mass flow rates.

> Heating, drying or heat treatment of bulk materials of all kinds

By e.g. as petroleum coke, pasty media, dust, pastes and sludges. KÖLLEMANN 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 end a reaction.

One challenge mastered by extensive development is the compensation of the thermal expansion of the worm shaft. It is completely absorbed by the especially developed KÖLLEMANN carbon bearings with the smallest possible maintenance work and costs. The tongue-shaped shaft passages enable individual worm shafts to be replaced easily without dismantling the end wall or the other shafts. This  design leads to significant minimisation of downtime.

Our 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 in the best possible way, a variety of heat sources can be used, such as heat transfer oils, various conditioning of water vapor as well as a purely electric heating.

The proven KÖLLEMANN self-cleaning principle is advisable for use with highly adhesive or pasty bulk materials. Thanks to the perfected shaft geometry, good conveyability of problematic bulk materials and outstanding heat transfer is possible.

Can be used for all bulk solids and temperatures up to 450 C°

Optional modular insulation

Optional with pipings, fittings and valves

Use of proven and tested hollow flights

Safe and reliable separation of heating medium and bulk material

Single or multiple shaft version

According to the hollow-flight principle, screw flights are hollow, so that they provide a path for a cooling or heating medium to flow through. This means that bulk materials that have to be thermally processed, can be cooled, heated or kept at a constant temperature. Screw conveyors with conventional design only allow the heating or cooling medium to flow through the housing and optionally the worm shaft, where as the hollow screw flights of our KÖLLEMANN screw-heat-exhanger are used for heat or cooling transfer by means of a thermal medium along the entire length of the screw. With the active use of the screw flight as heat exchange surface, the efficiency of the thermal heat transfer of a screw heat exchanger increases disproportionately. The hot or cold surfaces of the screw flights are in constant contact with the bulk product and allow an optimum heat exchange .

The screw flight surface makes up more than two-thirds of the entire product-contacting surface of a screw heat exchanger. Thus, compared to conventional products, the Köllemann screw-heat- exchanger has considerably more area per meter of conveying path and thus a considerably higher efficiency.

The supplied heat is utilized to the maximum by minimizing radiation losses. This results in a multiple of the transfer capacity and is the only reason why applications in higher performance ranges can be realised at all. This process  offers great advantages in terms of maintenance, service life, efficiency and space requirements of the machine. This design allows maximum performance in the smallest space.

Your contact partner

Matthias Ginster
Head of Sales