Chemical Engineering September 2023 - 55

Water Management 2023 Special Advertising Section
Static mixers with low pressure drop
Ross LPD Low Pressure Drop Static Mixers are ideal for effective fluid mixing in water and
wastewater treatment processes
he Ross Low Pressure Drop (LPD) Static
Mixer enables more efficient dosing
of flocculants, disinfectants, neutralizing
T
agents and pH conditioners into a water
stream. This simple-to-install heavy-duty
device completely mixes treatment chemicals
within a short length of pipe. When
used in conjunction with automated instrumentation,
the LPD delivers predictable
quality control based on a virtually maintenance-free
operation.
The LPD Static Mixer consists of a series
of baffles or " elements " discriminately positioned
in series. Each element comprises a
pair of semi-elliptical plates set 90 degrees
to each other. The next element is rotated
90 degrees about the central axis with respect
to the previous baffle set, and so
on. For even lower pressure drop, an LLPD
model is also available, in which the plates
of each element are oriented at 120 degrees
relative to each other.
As the fluid moves through each LPD
Four or six mixing elements are usually
more than sufficient for effective mixing
under turbulent flow conditions, Ross says.
Diameters range from 1 in. through 48 in.
or LLPD element, flow is continuously split
into layers and rotated in alternating clockwise
and counterclockwise directions.
This method of subdividing the stream
and generating striations leads to highly
efficient and repeatable mixing with minimal
pressure loss. During turbulent flow,
the baffles enhance the random motion
of molecules and the formation of eddies.
In most water and wastewater processes,
four or six elements are more than sufficient
to completely disperse treatment
chemicals and create a very uniform solution
or suspension.
Small LPD/LLPD mixers of 1 in. through
2.5 in. in diameter are welded to a central
rod, while larger elements are welded to
four outside support rods for maximum
rigidity and stability. Available in a wide
range of sizes up to 48 in. in diameter, these
mixers can be supplied as pipe inserts or as
complete modules with housing and injection
ports.
In addition to Static Mixers, Ross also
manufactures High Shear Mixers and MultiShaft
Mixers used in the production of
water treatment chemicals. The company
offers no-charge mixer testing services and
an extensive trial/rental program.
www.mixers.com
Peristaltic Dosing Pumps Meet the Challenge of
Delivering Dirty Fluids and Chemicals that Off-Gas
P
eristaltic metering pumps excel at pumping dirty fluids that contain
particulate matter into lower pressure systems because
they have no check valves to clog; and the gentle forces created
during the peristaltic pumping action will not damage delicate fluids
within the tube.
Peristaltic pumps are also extremely effective when pumping fluids
that contain trapped gases. Chemicals such as chlorine and hydrogen
peroxide tend to release absorbed or occluded gases when
subjected to a vacuum or changes in temperatures. With peristaltic
pumps the bubbles are simply pumped through the pump tube,
eliminating the possibility of vapor lock and loss of prime.
In addition, peristaltic pumps are capable of injecting into a
vacuum without the need for metal spring loaded valves. Their output
volume does not change due to changes in system pressure.
Peristaltic pumps easily prime
under maximum pressure, but
can be limited to maximum discharge
pressures of around 125
psi.
An energy company located
in Florida needed pumps to inject
12.5% sodium hypochlorite into
reuse water to prevent biological
build up within the water tubes
of their condenser. Any build
up within the condenser would
greatly reduce efficiency to proCHEMICAL
ENGINEERING WWW.CHEMENGONLINE.COM
duce steam, hence less mechanical
power.
The company chose a CHEMFEED
Duplex Skid System equipped
with two of Blue-White's FLEXFLO
Peristaltic Chemical Dosing Pumps.
The peristaltic pumps maintained
their flow without losing prime.
Although peristaltic pumps require
almost no regular maintenance, pump tubes degrade and
must occasionally be inspected and replaced. Blue-White's exclusive,
patented Multi-Tube Technology provides optimal performance
and tube life while operating at much higher pressures than conventional
single tube designs. The Multi-Tube design delivers tube
life up to four times longer than average single tubes.
All of the company's Peristaltic Pumps are equipped with a patented,
built-in Tube Failure Detection System (TFD). This technology
detects a wide range of conductive chemicals with no false triggering.
If the TFD detects tube failure, the pump will automatically
shut off and energize a relay switch. This permits communication
with external equipment, such as a back-up pump or alarm. It also
serves to prevent chemical spills and added downtime.
In conclusion, peristaltic metering pumps have proven to be accurate,
dependable, and tough in a multitude of commercial, industrial,
and municipal chemical metering applications. They are an
excellent choice when pumping fluids that contain particulates or
trapped gasses.
SEPTEMBER 2023
www.blue-white.com
55

http://www.mixers.com https://www.blue-white.com/industries/industrial/industrial-peristaltic-metering-pumps/ http://WWW.CHEMENGONLINE.COM

Chemical Engineering September 2023

Table of Contents for the Digital Edition of Chemical Engineering September 2023