Epsilon Archive for Student Projects

Abstract

In Sweden, grass is the single largest crop grown. Nearly 1 000 000 Ha grows on the
fields, this is primarily used as feed for livestock. To get a good seed, you need to
handle the crop carefully from planting to delivery. The part that I have been
interested in, is how to dry the harvested seed with out destroying the growth in the
small seed. This is very easily done if you aren't careful during the drying period. To
get a good result you need to spread the seed even over the dryer. You also need to
get an even quality on the stock that is placed on the dryer, this is more important than
in other plant drying. One other difference is the heating of the air used to dry the
crop. This may not be over 8 degrees Celsius otherwise you risk to spoil the growth in
the seed. If you do this, the seed becomes useless and will be rejected by the dealer.
There are no alternative uses for this seed.

I made two different tests according to the drying process, they are:
&#x1000BE Measurements of the static pressure in the main channel, temperature,
storageheight and the evaporation of water from Ryegrass.
&#x1000BE The accuracy of different meters for moisture content.

My tests have resulted in that i have been aware of the meaning the airflow and
pressure has for the affectivity and drying costs. I have also been aware of the
importance of calculating on a dryer to get the most effective drying as possible.

The result of my work was that i learned how important it is to be careful during the
drying procedure. If you don't check the temperature and the moisture in the air, there
is a great risk to make the crop wet again.

The dryer that i have been calculating on, is by my calculations, dimensioned in the
wrong way. But thanks to the farmer's knowledge and big interest, the dryer works
satisfactionaly.

I have also been interested in how the variations between different water meters for
crops variate. My result is that in order to get as right value as possible you must
weigh the crop. The kind of measurer that reads the resistance in the crop is not as
accurate as needed.

Vallen är den största odlade grödan i Sverige i dag med ca 1 000 000 Ha. Till denna
areal behövs ett bra utsäde. För att få detta vallfrö krävs att man hanterar fröråvaran
på ett riktigt sätt, från sådd till leverans.
Det jag inriktat mig på att undersöka är: Hur skall vallfröet behandlas under
torkningsprocessen för att behålla hög kvalitet på fröet. Det viktigaste är att behålla
grobarheten i fröet. Detta kan lätt förstöras om man beter sig på ett felaktigt sätt under
torkningsprocessen.
För ett lyckat torkresultat måste vallfröet fördelas jämnt över torken, man måste även
se till så att man har en jämn kvalitet på partiet som man lägger in. Beroende på de
låga luftflödena är detta viktigare här än i spannmålstorkning. Ytterligare en skillnad
mellan spannmålstorkning och vallfrötorkning är värmetillsatsen. Vid högre
värmetillsats än ca 8 grader i insugningsluften finns risk för att fröets grobarhet
fördärvas och fröet blir därmed odugligt. Alternativa marknader för vallfröet finns
inte. Har man fördärvat grobarheten är fröet värdelöst.
Jag har gjort två försök med anknytning till vallfrötorkning: