Lorentz PS200 Instructions For Installation Operation Service page 57

Principles of Operation continued
HELICAL ROTOR MODELS ONLY
Motor with
helical
rotor
attached,
stator
housing
removed.
Sealed cavities trap water and
progress toward the outlet
helical rotor
rubber stator
Positive displacement action The helical
rotor pump differs from centrifugal pumps in
that it maintains high efficiency and lift
capacity even at low rotational speeds and
low flow rates. This allows the pump to work
with a small, inexpensive solar array, and to
function in low sunlight conditions.
The helical rotor pump has only one moving
part. It produces a smooth flow and requires
no valves to function. It is far more reliable
than diaphragm and piston-type solar
pumps.
Self-cleaning action
full surface of the rubber stator with every
turn. It is impossible for deposits to accumu-
late. Solid particles tend to roll away from the
contact area, making the pump extremely
resistant to abrasion. Particles that are
trapped against the rubber are tolerated by
the flexibility of rubber.
Some history Helical rotor pumps have
been used in the oil industry for over 60
years. They are used to pump concrete! They
have been used for solar pumping since the
1980's, but were very expensive until the
LORENTZ helical rotor pump was intro-
duced.
The rotor sweeps the
is a test specimen
is almost like new,
Close-up of the
same rotor. This
that pumped
extremely sandy
water for 500
hours in the test
lab. The surface
and the pump
performs to full
specifications.
57