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Counterflow coolers and dryers for feeds, pellets from biomass, RDF, SRF. 

Coolers and dryers for wood pellets.

Cooler for pellet mill


Indispensable element of any industrial pelleting line

NPT manufactures a complete capacity range of counterflow coolers for granulated feeds and pellets from other raw materials. The efficient operation of the cooling system allows the pellets to be cooled to a temperature of only 5°C - 10°C above the ambient temperature. In addition, the pellets gain resistance to mechanical damage. Due to the reduction of humidity, the calorific value of energy pellets increases (from wood, agricultural biomass, RDF / SRF / ASR, etc

Modern and safe design

  • Anticorrosive construction made of stainless steel: cover, walls, discharge, fire valve, air outlet

  • Smooth internal surfaces: elimination of pellets and dust retention and fouling contamination (or other raw materials),

  • Durable mechanical structure guarantees many years of use,

  • Minimization of external surfaces on which dust and dirt can settle, where difficult to clean,

  • Quick and thorough cleaning of all internal and external surfaces,

  • Full emptying of the cooler from every feed mixtures,

  • The minimum gap between the moving and fixed floor ensures tightness and uniformity of cooling and drying, also for micropellets 1.8 - 2.2 mm.

  • Large inspection doors allow easy access to the interior of the cooler,

  • As standard equipment, stainless aspiration lock with drive,

  • It is possible to adjust the shape of the discharge to individual requirements,

  • On request, it is possible to change the standard discharge height,

  • On request, an individual service platform with stairs,

  • Integration with the crumbler (working in tandem) allows to reduce the necessary height of the cooling-crushing unit.

A complete system for removing moist air

  • Adjusting the air flow: fans controlled by an frequency inverter or a manual air damper,

  • Efficient and economical fans with power from 5.5 kW to even 45 kW,

  • Stainless steel pipes with a diameter from 400 mm to 900 mm, flange connection,

  • Single cyclones made of stainless steel with aspiration lock,

  • Insulation of pipes and cyclone (insulation mats) protects the installation against precipitation of water in case of temperature differences (it is not necessary to use expensive air heaters),

  • Roof hood made of stainless steel.


Floor and outlet

  • Optimal regulation of cooling level and humidity reduction,

  • Possibility of programmable floor gap adjustment (3 programs available in AIAC)

  • The possibility of an optimal adjustment of the cooling time of individual feed mixtures or other raw materials guarantees optimal granulating treatment

  • Continuous operation (instant discharge) or step mode,

  • The radiator floor and grate are designed to prevent pellets from being crushed. This increases the efficiency of the entire pelleting line by significantly reducing dust and sifting,

  • The floor movement is implemented via 2 pneumatic actuators,

  • In the event of a power failure, the discharge mechanism is automatically closed, which protects the next device from backfilling.

  • Available electric version of the drive,


Internal pellets distributor

  • Standard equipment in coolers with floors from 2.4 x 2.4 m up.

  • Each radiator can be equipped with a pellets distributor,

  • Guarantee of equal distribution of pellets on the entire surface of the cooling table,

  • Single drive and simple, rugged construction ensure long life

  • Easy operation with access through inspection doors,

Work and production safety

  • Level sensors Endress + Hauser in the cooling chamber (3 pcs.)

  • Level sensor on the discharge in the funnel,

  • One level sensor in the cooling chamber with adjustable mounting height,

  • Rack temperature sensor [mounted in the floor],

  • Ambient air temperature sensor,

  • Inductive sensor for opening inspection doors [coupled with line visualization],

  • Transport lock flow sensor,

  • Temperature sensor at the air outlet signals the possibility of fire hazard,

  • Air temperature sensors inside the chamber [depending on the size of the chamber: 2 or 4] coupled with the MBS negative pressure transducer,

  • Fire-resistant air damper with immediate shut-off of air intake, reduces to a minimum the possibility of spreading fire,

  • The pneumatic air damper drive works even when the power supply is cut off,

  • Water extinguishing system (manual or automatic) with two spraying nozzles,

  • The discharge outlet can be equipped with a flow scale, which gives real values ​​of the production volume.

  • Design and production in accordance with CE and ATEX safety standards,

  • Explosion proof membrane protects the pelleting line and operators against uncontrolled explosion,

  • The AIAC system reacts immediately when the temperature is exceeded and starts emergency procedures,

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