Lumina 750
Basic working principles
2.4.3
Circulation control
The Lumina 750 controls the circulation by speed of the fan. The circulation control has the following functions:
●
Correct air distribution in the tunnel,
●
Bringing or keeping the temperature differences in the compost within acceptable limits,
●
Ensuring a more intensive heat exchange between the air and the compost if there are too high compost
temperatures.
Control options
How the circulation is controlled is determined by one of four fan control options, namely:
%
,
m3/h
,
m3/h/t
and
%/
t
. One of these is selected during installation (see the Installation manual).
The Lumina 750 determines the circulation based on this configuration:
•
%
: Circulation values are set and displayed in %.
•
m3/h
: Circulation values are set and displayed in cubic metre per hour.
•
m3/h/t
: Circulation values are set and displayed in cubic metre per hour. The total amount of tonnage in the
tunnel is used to calculate the minimum and maximum circulation.
•
%/t
: Circulation values are set and displayed in %, but the percentage depends on the tonnage in tunnel. The
percentage is pre-set in the circulation table.
Circulation table
Only the option
%/t
uses the circulation table (see picture below).
The circulation table gives optimal control of circulation. Each phase has a circulation table (pre-phase setting).
The table links the tonnage (
T
) to a certain amount of circulation (minimum, maximum and increase/day in %).
After setting up this table, the Lumina 750 automatically selects the right amount of circulation (
%
) for the tonnage
that is in the tunnel.
The pre-set amounts of compost (
T
) in the circulation table are the same for all pasteurisation phases and all
mycelium phases.
2.4.4
Compost temperature control
The Lumina 750 uses the air temperature to control the compost temperature. If the average compost
temperature is higher or lower compared to the
Compost temperature control value
, the difference can be
corrected by adjusting the air temperature.
A too high compost temperature can be decreased by increasing the fan speed. The fan speed will create a more
intensive heat exchange between the compost and the air.
The compost temperature control can also be used to eliminate differences between compost temperatures. The
fan speed will be used for levelling the compost temperatures.
2.4.5
O2 control
The Lumina 750 controls the O
2
concentration on the basis of the O
2
control value. If the O
2
content drops below
the control value, fresh air will be introduced in the tunnel, even if the air inlet temperature is too low. If the O
2
concentration rises above the control value, the amount of fresh air will be decreased.
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