27
26
FLOW DIVIDERS
Delta Power Company
4484 Boeing Drive - Rockford, IL 61109
WARNING:
The specifications/application data shown in our catalogs and data sheets are intended only as a general guide for the product described
(herein). Any specific application should not be undertaken without independent study, evaluation, and testing for suitability.
Phone: (815) 397-6628
Fax: (815) 397-2526
E-mail:
Application Data
The Delta flow divider is a positive displacement flow dividing or proportioning apparatus. It will divide the flow from one
source into two or more equal or proportionate circuits, and intensify or reduce the pressure level as required. Note that
these flow dividers will operate in reverse in a combine mode, but in that mode, the accuracy likely would be significantly
reduced.
In its basic configuration, the unit consists of a number of inter coupled gear type hydraulic pump motors. Each section
must be capable of performing the pumping or motoring function. The section have a common inlet and separate outlets.
Fluid from a prime source, such as pump, supplies the motive power to the flow divider. No energy is added to the fluid in
the device, although each outlet may have an energy level difference than any other section. When the sections are of like
size, the function is to divide the total flow into equal increments of flow, and when the sections are of unlike size, the
function is to divide the flow into proportionate increments relative to the chosen geometric displacements.
Since the flow divider is a positive displacement machine, it will accomplish its function over a wide range of pressure of
viscosity differentials. Nevertheless, certain limits are imposed due to slip characteristics and torque losses in the
machine. Therefore, the performance criteria in this paper will be developed around a unit of average tolerance allowance.
The data, so derived, will be averaged. Be aware that these units can require a certain amount of break-away pressure. It
is recommended that operation at low pressures (< 100 PSI) is not attempted without consultation with the factory.
General Relationships
In any unit, neglecting any losses, there exists the relationship that
Q
i
= Q
1
+ Q
2
+ …. Q
n
;
Where Q
i
is the flow into the unit and Q
1
, Q
2
and Q
n
are the displacements out of each section. Since no energy is added
and if none were lost, it follows that
P
i
Q
i
= P
1
Q
1
+ P
2
Q
2
+ …. P
n
Q
n
;
Where P
i
is the pressure into the unit and P
1
, P
2
and P
n
are the pressure levels out of each section.
In a unit consisting of any number of/or sizes of sections
P
1
Q
1
+ P
2
Q
2
+ …. P
n
Q
n
P
i
=
Q
i
In any actual case, the above theoretical observations must be corrected to encompass the pressure drop and slip losses
in the flow divider. The pressure drop is primarily a function of the amount of fluid and viscosity. At the usual viscosities
(100 to 300 SSU) encountered in hydraulic systems, the pressure drop
∆
P
p
, can be approximated by the relationship,
where n is the number of sections,
6Q
i
∆
P
P
≅
+25
n
Since the flow divider itself is a parallel circuit, the actual pressure P
ia
into the unit is
P
1
Q
1
+ P
2
Q
2
+ …. P
n
Q
n
P
ia
≅
+
∆
P
P
Q
i
Page 37
FLOW DIVIDERS
Delta Power Company
4484 Boeing Drive - Rockford, IL 61109
WARNING:
The specifications/application data shown in our catalogs and data sheets are intended only as a general guide for the product described
(herein). Any specific application should not be undertaken without independent study, evaluation, and testing for suitability.
Phone: (815) 397-6628
Fax: (815) 397-2526
E-mail:
Slip is a function of the viscosity, pressure differential and clearance and can be estimated from the following chart:
Model
Displacement
Gal./Rev./Sect.
Slip/100 PSI
(GPM)
Max. Flow/Sect.
(GPM)
PM2 .00047
.03
2.0
PM6 .00137
.04
5.5
P21 .00178
.06
7.6
P23 .00304
.07
12
P25 .00425
.08
17
P26 .00531
.10
20
P27 .00633
.11
25
P43 .01020
.15
35
P47 .01690
.22
50
The slip function increases or decreases the flow from a section, dependent on whether the pressure differential is
positive or negative across that section.
The performance of a system would be determined in the following manner.
1. Determine the size of the sections that will best give the required flow and pressure. The displacement from each
section will be the fractional proportion of the sectional displacement versus the sum of the displacements of all
the sections. That fraction multiplied by the input flow gives output displaced by each section.
6Q
i
2. Determine
∆
P
p
from
∆
P
P
≅
+25
n
P
1
Q
1 +
P
2
Q
2
…. P
n
Q
n
3. Determine P
ia
from P
ia
≅
+
∆
P
P
Q
1
4. Determine the pressure differential
∆
P
1,
∆
P
2,
∆
P
n
across the individual section where
∆
P
1
=
∆
P
ia
-
∆
P
1,
etc., and
from this value, determine the slips S
1
, S
2
, S
n
.
5. Determine Q
1a
, Q
2a
, Q
na
from Q
1a
= Q
1
+ S
1
, etc.
The foregoing description is intended as an aid in determining the results of a flow divider system. Any specific application
should not be undertaken without independent study, evaluation and testing for suitability. Exceeding the specifications
could result in equipment malfunction, property damage, serious injury or death.
Page 38
POSI LOCK®
100-TON & 200-TON
Hydraulic Puller Systems
Flow Dividers
POSI LOCK®
100-TON & 200-TON
Hydraulic Puller Systems
Flow Dividers
