Air heaters

Air heaters type NPA

NPA air heaters are designed to produce hot process air and are mainly used in grain or herb dryers. They are also used to heat large storage facilities, plastic tunnels, greenhouses, etc.

The machines are adapted to work with grain dryers, like, for example, Araj, Riela, Drzewicz, etc. They may be used wherever it is possible to use renewable fuels, often inutilely lost.

A BRIEF DESCRIPTION OF THE MACHINE

NPA air heaters use a counter current biomass combustion system with adjustable and properly arranged air blow enabling the achievement of better performance of the combustion process. This process is as follows: the air blowing fan to the combustion chamber, controlled by a microprocessor controller, sucks in air and feeds it to the combustion chamber to the places of the combustion of the charge. The heat produced as a result of the combustion is released into the air supplied by the air blowing fan. Then, the hot air can pass to the receiver through the duct system. The air is heated in exchangers directly from the heat generated during the combustion of straw (without a medium, like, for example, oil or water). This design enables the achievement of the increased efficiency of the machines and higher air temperatures.

In order to obtain an optimum exhaust composition it is advisable to use seasoned straw with a moisture content of up to 15%. NPA air heaters are not subject to Technical Inspection and registration at the Inspectorate of Technical Inspection.

FUEL

The basic fuel for firing NPA air heaters is pressed straw of four types of grain and rape with a moisture content of up to 15% in the form of bales with dimensions of fi1500x1200 mm. The combustion of straw with a higher moisture content will reduce thermal efficiency and accelerate the wear of the heater and the chimney installation. The combustion of straw seasoned less than a year may accelerate the corrosive wear of the heater. Moreover, the combustion of straw with a moisture content of above 30% is energetically unacceptable and economically unjustified. Where necessary, an alternative fuel may be wood waste and branches.

ADVANTAGES:

  • -efficiency of about 75%
  • cheap fuel (straw, hay, etc.) 4 kg straw= 1 litre of heating oil
  • easy operation
  • compact design
  • environmentally-friendly combustion of straw


Each heater has CE marking, the construction meets the requirements of European Union Directives.

It is possible to produce heaters with parameters other than those listed above.


Details Unit NPA 250 NPA 350 NPA 600 NPA 850 NPA 1100 NPA 1300 NPA 1600 NPA 2400
Boiler power rating* kW 250 350 600 850 1100 1300 1600 2400
Heated air temperature C 110 105
Heated air flow rate m3/h ~7000 ~10000 ~18000 ~22000 ~36000 ~40000 ~54000 ~72000
1 bale fi 1 bale fi 2 bales fi 2 bales fi 3 bales fi 3 bales fi 3 bales fi 4 bales fi
Fuel load 120x120 150x120 150x120 150x120 150x120 150x120 180x120 180x120
Straw moisture % 15
Weight of one charge kg ~140-170 ~240-250 ~480-500 ~480-500 ~720-750 ~720-750 ~960-1000 ~1200-1400
Weight of unit with ceramics (gross) kg ~7000 ~9000 ~11000 ~13000 ~19000 ~21000 ~25000 ~30000
Required exhaust draft Pa ~55 ~65 ~75 ~85 ~95
Chimney height m 12 15 16 20 22 24 24
Chimney section fi 300 350 450 500 600 600 800 900
Thermal efficiency % ~75
Installed capacity kW ~9 ~9 ~14 ~18 ~29 ~29 ~44 ~49
Heater length ** mm A 3100 3550 4740 5260 6250 6250 6250 8200
with fan ** 4500 4700 7000 7800 8800 8800 9200 11200
Heater width ** mm B 1700 2100 2100 2100 2100 2100 2400 2400
with control box ** 2350 2450 2450 2450 2450 2450 2750 2750
Heater height ** mm H 2180 2575 2590 2700 2700 2800 3200 3300