Choosing equipment for drying and chipping

As is known, the production of pellets and briquettes from wooden waste as well as from other types of biomass needs the raw material to be chipped first and then dried up 10…12% of moisture content. To do this different equipment can be used. In the XX century one of the most well-known complexes with this aim were drying drums and hammer chippers. But in the XXI century it became necessary to reach one more economic purpose – energy efficiency. That is why we created an innovative equipment for drying and chipping Aggregate “AC”. This equipment was presented at the market only in 2008 that is why some may doubt whether to use this equipment or not. Since the best way to make a decision is to compare we decided to compare the named aggregate with other equipment for drying and chipping of wooden waste. The most popular and well-known in this sphere in Russia is complex AVM-1,5 (aggregate for vitamin flour), which was previously installed in all kolkhozes and which is now used to prepare wood and agriculture waste for pelleting and briquetting.
We will start the comparison from one of the most important features – energy intake. Here we provide a table with the information on engine capacities.
Attached electric capacity, kW
Name of the equipment
Working on wood shredding
Working on chips
AVM-1,5 AS-4-1000 AVM-1,5 AS-4-1000
Disintegrator engine - - 55 –
Transporter engine - - 3 –
Drying drum engine AVM-1,5 11 - 11 –
Rotor engine AS - 75 – 110
Classifier AS - 7,5 - 7,5
Fan (fume outlet) 55 22 55 22
Cyclone floodgate engine 3 1,5 3 1,5
Chipper engine 55 - 55 –
Settling cyclone fan 15 - 15 –
Cyclone floodgate engine 1,5 - 1,5 –
Total 140,5 106 198,5 141

As one can see from the table, AC takes 24% less energy than AVM-1,5 when it is working on wood shredding and 29% less when it is working on wood chips. What does this mean in practice? If your work in 2 shifts (18 hours) 22 days a month the difference in kWh will comprise 13 662 and 22 770 correspondingly. Thus, in today’s prices for the energy 5 RUR per kWh using AC instead of AVM-1,5 will economize you 68 000 RUR when working on wood shredding and 114 000 RUR when working on chips, and this is only for one month. Here comes quite a logical question – what brings this economy? The answer is quite simple – correctly organized process of drying and chipping. Everybody knows that it is easier to process wet wood and it is easier to dry chipped wood – and this is the way how Aggregate AC works (in AVM it is done the other way round).
But the advantages are not only about economizing energy. Let’s compare other features.
Feature AVM-1,5 AS-4-1000
Necessary area, minimum, m2 100 10
Necessary height of the building, m 9 7
Cost of the new module building, RUR 3 000 000 1 000 000
Cost of the fundament, RUR 1 500 000 0
Transportation costs, RUR per 1000 km 150 000 25 000
Number of electric engines 6 (8) 4
Number of expensive bearings 8 2
Necessity to change sieves frequently yes no
Possibility to regulate the size of chipped particles remotely no yes
Possibility for quick start and stop no yes
Fire threat very high extremely low
Possibility to move the factory to another place very difficult not difficult
Period of equipment production, months 6 2
Period of installation, months 3 1
Period of commissioning, weeks 4 1
Period of reaching the project capacity, months 3 1
Increase of the productivity of further pressing, % 0 50 and more
We pay your attention to the last line in the table. The dry wood shredding after AS are more plastic than the ones from AVM. As a result a brick press which usually produces 400 kg per hour after AS can make 630 kg per hour and more. We think that now the decision is obvious!