Micron Technology Turbofan - Manual (Page 9)

DRAFT
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4.2.2 Parallel Connection
The hydraulic motors of the Turbofan are normally connected in parallel.
To calculate the hydraulic flow required for a specific number of heads :-
• each head runs at 4000 rpm
• the oil flow required per motor is 4000 x 2ml/rev = 8 1/min
• add 10% for pump and other hydraulic losses = 8.8 l/min
eg For 6 heads hydraulic flow required = 8.8 x 6 = 52.8 l/min
Alternatively if you know the maximum hydraulic flow available from the tractor or PTO
pump, etc for the Turbofans then :
Maximum number of heads which can be installed = Maximum hydraulic flow available
8.8
eg If flow available = 72 l/min
then maximum number of heads (in parallel) = 72 = 8.18 = 8 heads
8.8
The pressure drop required per Turbofan Sprayhead is 100 bar (1500 psi) therefore the
maximum pressure required by the total hydraulic system for parallel running = 100 bar
(1500 psi).
4.2.3 Series
Connection
The preferred method of running Turbofan Sprayheads is in parallel. However, if more
sprayheads are needed than can be connected in parallel, then series connection can be
used, subject to the following:
• A maximum of two motors must be used in each series chain.
• A hydraulic system with a relief valve setting of 200 bar (or above) is necessary for
series running (i.e. pressure drop of Turbofan unit x 2 = 100 bar x 2 = 200 bar).
• It should be noted that most tractor hydraulic systems operate below this figure and
are therefore unsuitable for running Turbofans in series (i.e. typical tractor hydraulic
systems operate in the range 140 – 180 bar).
It must also be noted that if the hydraulic system is running at 200 bar (or above) then all
of the components in the circuit must be capable of withstanding these pressures.