Continuous automatic blending of gear
oils is accomplished
by synchronizing a
series of pumps and
meters so that desired
proportions of ingredients are fed to
a blender or
homogenizer where the
mixing is completed. Such a
blender is of rather
small cubical capacity, perhaps holding
a barrel of
fluid; therefore , the
entire system contains
a minimum of fluid at any one time.
For this reason changes from one grade to another necessitates very little
rejection of oil. Several equipment manufacturers
offer systems to
accomplish the above purpose
and most compounders rely
on such firms
rather than design their
own blending equipment. Details of such systems, which
include “Bowser Blending Systems”, “Cornell Proportioning Units” or “Proportioneers Oils Bending Unit”, can be
obtained from the distributers.
One such unit which is used for
blending gear oils is shown. In this
instance the supply
of oil comes from storage tanks outside
the building, and the
pumps at the tanks are remotely controlled at the blending
unit. The oil passes through air eliminators, pressure controlled, and
automatic temperature compensating proportioning meters. From the
three meters the
fluid goes into a
common header, through a
master meter, and then
into the blender from which it can
go to storage or
through a small surge tank
to package. This unit is installed over
a great which
allows any spillage
to drain to a waste tank
in the basement of the building. With such
systems two to
six or eight
different components can be blended. While there
are variations in the
different systems, a typical one
uses a series of
positive displacement piston
type meters in which a
selector at the top of
the meter sets a train
of gears to
determine the delivery. The flow rates of a ¾ in. meter can
be varied from 0.4 to 15 gpm and of a 3 in. size from 10 to 250
gpm.
Where a
single additive is to be
introduced into an oil
and no further blending
is desired, a continuous
system of injection mixing can be used. One of the
most positive means for
injection mixing is to
use an injection
pump driven by a
motor which is controlled
by an interlocking
switch connected to that
of the oil line pump
motor. The injection pumps
are generally adjustable
over a 10 to
1 capacity range and have capacities varying from 5 cc/min to 40 gpm. No pump is required
if the additive is introduced by the pressure of a closed tank. In this case
a flow indicator, such as a “Rotometer ,” can
be included in the additive
line and a
calibration point arrived at by
checking the consumption
of the additive
over a given period
with the gallonage
of oil pumped.
In these
automatic blending units
provision is made to
either stop the
flow or continuously
recycle the mixture
without delivery if
the flow of
one or more
of the ingredients cease. Also,
when changing blends
the mixer can
be either sucked
or blown dry to prevent
contamination. Since
continuous automatic blending
of gear oils decreases
the labor and
supervision of such operations
and also affords
considerable saving in space
requirements, such methods should
have consideration in all
new installations of any
magnitude.
