2. Downstream pipe should always be as large or larger than the pipe diameter of the MIXING EDUCTOR
3. Maintain Minimum FT/HD as possible.
4. Install on a level flat surface.
5. Secure skid base to deck.
3. Keep steady pressure above 30 PSI. Back-flow may occur, below 20 PSI. Maintain 40 PSI (92 ft./HD)- 50 PSI (115 ft/HD) across eductor for good performance.
The Lobestar shear mixer is a Venturi device designed on the Bernoulli Principle of "when velocity is high, pressure is low and inversely when pressure is high, velocity is low".
In operation, a centrifugal pump is used to deliver
the pressure energy to the Lobestar shear mixer. The pressurized
liquid is converted into a high velocity stream as it passes through
the converging shape of the jet nozzle. The resulting high velocity
stream generates a low-pressure region around the issuing jet stream
producing a strong suction.
Powders, granular materials and other chemical additives dosed in through
the hopper are drawn-in by the suction and pre-wet under a high "G" force
generated in the Radial Premixer. The slurry then enters the mixing chamber
of the Lobestar Eductor to be dynamically sheared and dispersed. The
blended slurry travels through the diffuser (pressure recover tube) to
gradually convert the high velocity back into pressure at the Eductor
discharge with as efficient pressure recovery as possible.
The Lobestar shear mixer has no moving parts. The four (4) major components of the Lobestar shear mixer are: (1) Hopper, (2) Valve, (3) Radial Premixer, and (4) Lobestar Mixing Eductor. The Lobestar Mixing Eductor is composed of: (1) Jet Nozzle, (2) Suction Inlet, (3) Mixing Chamber and a (4) Conical Diffuser.
The orientation of the Lobestar shear mixer is an important consideration for suitable performance. The direction of flow is from the Jet Nozzle inlet end to the diffuser discharge end. The pressure line (hose or pipe) from the centrifugal pump is connected to the Jet Nozzle end of the Eductor. The Diffuser end of the Eductor is connected to the downstream hose or pipe that is routed to the active fluids system.
The Lobestar shear mixer is designed around a streamline flow stream. A streamline flow is based on a constant uninterrupted flow. This means that any downstream obstruction will decrease the Eductor efficiency.
Installation considerations:
1. Check to see that the pressure
side of the centrifugal pump is connected to the Jet Nozzle end of
the eductor.
2. The suction valve located below the hopper must be in the closed position
before operating the Lobestar shear mixer. When pipe pressure is 25 psi
or more, gradually open valve.
3. The pipe or hose size should be as large or larger than the model
size of the eductor. Model V VE-U-4S/D has a 4" discharge. The downstream
pipe must be 4" or larger.
4. Avoid placing downstream obstruction in the downstream pipe, such
as valves.
5. When installing elbows in the downstream pipe, the first elbow should
be a least four (4)-pipe diameters from the discharge end of the eductor.
2. Close the hopper feed and RADIAL PREMIXER valves.
3. Make sure there are no pipe restrictions or obstruction downstream from the Mixer.
4. In routing the piping downstream of the eductor, the horizontal distance of the first elbow should be a minimum of 4 pipe diameters. Example: If a 4” model eductor is installed, the 1st elbow should be 2’ from the discharge end of the eductor.
2. Check inlet pressure and vacuum gauges.
3. When the pressure reaches its recommended range, (40-50 PSIG) open hopper feed valve.
4. Slowly open RADIAL PREMIXER valve.
5. Look into the hopper throat and adjust valve to develop strong vortex in the RADIAL PREMIXER.
6. The velocity of the vortex can be adjusted by opening or closing the valve.
7. The RADIAL PREMIXER should always be used while mixing chemicals and Bentonite.
8. The RADIAL PREMIXER should be closed when mixing Barite only.
Answer: (1) Restriction in the discharge line, (2) Valve partially closed on feed end, (3) Insufficient pump pressure, (4) Viscosity too high, fluid stall.
2. Problem: Valve hard to open.
Answer: (1) Clean Mixer Hopper after mixing product, (2) Hand grease
valve rubber gaskets, (3) Before installing victaulic gaskets,
spray with WD 40 or equivalent.
3. Problem: Loss of suction.
Answer: (1) Insufficient pump pressure, (2) Plugged or partially plugged
nozzle, (3) High viscosity, (4) Partially plugged lines down stream.
4. Problem: Premixer not performing.
Answer: (1) Insufficient pump pressure, (2) Plug or partially plugged
nozzle, (3) High viscosity, (4) Partially plugged lines down stream.
2. Hopper suction has strong vacuum - care should be taken when mixing chemical, keep hands away from suction throat of hopper.
3. Do not exceed maximum pressure of 80 psi.
4. NEVER! Close a valve down-stream from Mixer, while feed pump is running.
Spray heavy coating of WD 40 on all carbon steel surfaces for protection against severe seawater environment.
All non-metal parts such as urethane are non-corroding and should not need any surface protection.
Before applying oil coating and
storing, wash down equipment with fresh water and use soapy water
to clean internals, then proceed with oily protective coating.
The LOBESTAR NOZZLE,
PREMIXER BODY and DIFFUSER are constructed in high density, high
abrasion resistant urethane and alternatively could be of other materials
. Inspections of these parts, for wear, should be done every
6 (six) months for optimum performance.
An eductor is a pump without moving parts. An eductor is principally synonymous with a jet pump. They operate on the conversion of pressure energy into velocity to produce a low-pressure region.
2) How are they used?
They are used for the conveyance, compression and mixing of liquids,
gases and solids when a gaseous or liquid medium serves as the motive
or primary force.
3) What components make up
an Eductor or Jet Pump?
A. Motive nozzle. B. Induction passage (suction).
C. Mixing chamber. D. Diffuser (pressure recovery tube).
4) How does the LOBESTAR MIXING EDUCTOR differ from a conventional Eductor?
“LOBESTAR” MIXING EDUCTOR differs by using a unique three-dimensional nozzle. The nozzle orifice configuration has a circular core with elliptic shaped lobes around the radius of the circular core. This nozzle geometry generates a coherent turbulent flow pattern that energizes the boundary in the diffuser section of the eductor, providing efficient pressure recovery and intimate mixing in a short time to length scale.
5) How is the efficiency of an Eductor/Jet Pump determined?
A. Vacuum/inlet pressure ratio. B. Pressure recovery.
6) What is the maximum solids-to-liquid
concentration that can be expected?
Several pounds of solids per gallon liquid depending on the flow characteristics,
bulk density and required solubility.
7) What type of valve is
used with an eductor?
Slide gate, ball and butterfly valve are suitable. If powdered polymers
are mixed, slide gate valves are recommended to avoid passage obstruction.
Valves should never be used for dosing or metering control.
8) Why is a valve needed?
A valve is necessary to prevent flow-back caused from blockage or high pressure-drop that may cause "stall" in the downstream flow. It is used in start-up and shut down to prevent surges. It is also needed where the discharge line is at a higher elevation than the eductor.
9) What effect does viscosity of the motive liquid have on the performance of the eductor?
The lower the viscosity the greater the vacuum. Viscosity over 750 centipoises will significantly reduce the suction flow. The vacuum can control the rate of induction of feed and mix.
10) In what ways can an eductor be fed?
A. Manual dosing. B. Volumetric
feeder.
C. Pneumatic feeder. D. Mechanical conveyer.
11) Can a slurry be re-circulated
after mixing?
Yes. Remember, the higher the viscosity becomes, the lower the suction
if powder is continued to be feed into the system.
12) What line velocity should
be used in the downstream pipe?
6-8 ft/sec. should be considered a minimum.
13) What important factors should be considered in successfully operating an Eductor?
A. Matching-up a pump with
the size eductor to be used.
B. Minimize downstream elbows in the piping.
C. Discharge pipe should always be as large or larger than the diameter
of the eductor.
D. Survey piping for restrictions or possible blockage.
14) What is the importance of a centrifugal pre-wet chamber?
A. The centrifugal force
imparted on the mixture prevents lumping and "fisheyes".
B. Maintaining a level of liquid on the induction inlet (suction) that
will create a water seal, reducing air entrainment. When powders or solids
are added through the suction port, free air is entrained into the mixture.
The entrained air bubbles in the mixture will continually expand as the
pressure gradient through the pipe approaches atmospheric, causing larger
and larger bubbles that will effectively limit suction flow rate.
