Critical selection factors
for thermoplastic pumps
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Pumps Play Critical Role in Zero Discharge
Reprinted from Pumps & Systems
The pumps used in the recovery system behind this nickel/chromium
plating operation must handle acidic and alkaline plating and cleaning
solutions over a broad pH range, commingled chemical waste streams,
and DI high purity water recovered from the ion exchange system.
Here's how they do it.
When the process engineers at Columbia Manufacturing, Inc. (Westfield,
MA) decided to upgrade their chromium plating line, they were
determined to take advantage of the latest and most innovative
developments in quality manufacturing procedures while
simultaneously serving the growing demand to protect the environment
by minimizing or eliminating the discharge of chemical wastes.
According to Ali Salehi, senior vice president of manufacturing and
engineering, the company set these specific goals:
Find a way to recover and reuse a major portion of the 150,000-gpd of
municipal water required for cleaning, plating and rinsing the thousands
of feet of metal tubing used in the manufacture of school furniture and
Install process systems to recover and reuse the costly chemicals
required for the chromium and nickel plating solutions involved in
applying decorative and corrosion resistant coatings to the structural
tubular components of the products.
Create a waste treatment system that would eliminate costs related to
securing and maintaining exemption from the Massachusetts DEP air
and wastewater discharge permits.
These goals have been consistently met by the installation of an
automated, return-type nickel/chromium Napco plating system, and a
"zero discharge" resource recovery treatment system designed, built
and installed by CASTion Corporation (Worcester, MA) and Columbia.
This system is a custom-engineered Controlled Atmosphere Separation
Technolog (CAST) packaged concentrated wastewater and valuable
chemicals recovery system. CAST can be furnished as a stand-alone
wastewater and chemical recovery system, or as part of an integrated
plant-wide program to minimize or completely eliminate costly disposal
of hazardous waste or process effluent.
This patented program recovers close to 100 percent of valuable
chemical resources or wastewater and permits their immediate
recycling or reuse at the facility. Because of the wide variety and pH
values of process chemicals and waste fluids being treated and
transferred, pump design and material selection are critical and must be
integrated into the specifications of the custom-engineered wastewater
and chemistry recovery system.
Critical to the success of the innovative design features of this new
system was the ability to achieve safe and dependable recovery and
recirculation of the many costly chemicals used in the automated
plating systems, substantial reduction in the huge volume of municipal
water required in cleaning and rinsing operations, and the capability of
economically providing the large quantities of distilled water required
fro the counter current ion exchange system. The pumps selected had
to be able to handle acidic and alkaline plating and cleaning solutions
over a broad pH range commingled chemical waste streams, and DI
high purity water recovered from the ion exchange system.
To handle this variety of aggressive fluids, including sodium hydroxide,
hydrochloric acid, sulfates, dissolved inorganic contaminants, distilled
water and other waste chemicals, the system designers ruled out metal
pumps and specified that the pump casing, impeller, flanges and other
components coming in contact with the fluids must be made of solid
homogeneous Kynar® polyvinylidene fluoride (PVDF) from Arkema, Inc.
The specific pump construction selected for handling these corrosive
and aggressive fluids was the Chem-Gard CGA horizontal centrifugal
design from Vanton Pump & Equipment (Hillside, NJ) that meets
ANSI-B-73 and international DIN standards for process pumps.
These end suction centrifugal pumps combine low maintenance
centerline discharge and back pullout features and are constructed with
a unique wide open seal, sliding bar pedestal configuration that
simplifies seal inspection and maintenance.
The system utilizes three of these ANSI thermoplastic centrifugal
pumps: one pump for flows of 400-gpm against a 100-ft total dynamic
head, and two other pumps for flows of 200-gpm. All fluid contact
components are made of Kynar PVDF. Even the stainless steel shafts in
these pumps are isolated from the corrosive fluids by thick shaft sleeves
made of the same chemically inert thermoplastic.
The turnkey wastewater and product recovery system has resulted in the
All recovered wastewater is returned to the rinse baths, and plating
solutions that are recovered are returned directly to the plating tanks.
Concentrated wastewater from the cleaning and plating lines have their
own CASTion ion-recovery systems and are recovered as DI water and
are then recycled for use in the rinse tanks.
98 percent of the nickel and chromic acid platin chemicals are recovered
There is no discharge into sewer or air, so the company needs no
permits from DEP, and is exempt from RCRA permits.
Six hundred pounds of chromium trioxide are recovered each week and
returned to the plating tank.
As a result of these changes and installation of the recovery systems.
Columbia dramatically reduced its overall municipal water use from
150,000-gpd to 3000-gpd. The completely automated process and
wastewater treatment systems, using rugged, nonmetallic,
chemically-inert thermoplastic recirculation pumps, have substantially
increased productivity while reducing maintenance costs.
This closed loop plating facility and the CASTion zero-discharge flash
distillation wastewater and chemistry recovery system not only resulted
in appreciable cost savings, but also brought the company the
Governor of Massachusetts "Green Seal" award for service to the state
in its drive to improve the environment.
One of the three centrifugal pumps used to circulate corrosive fluids at
Columbia Manufacturing. All fluid contact parts, including the shaft
sleeve isolating the stainless steel, are made of Kynar® PVDF.
Diagram of the CASTion zero-discharge flash distillation system installed
at Columbia Manufacturing.
In the 1950, Vanton developed a revolutionary all-plastic pump for use in conjunction with the first heart-lung device. The design limited fluid contact to only two non-metallic parts: a plastic body block and a flexible liner. This was the birth of our Flex-I-Liner rotary pump. Its self-priming sealless design made it an industry standard for the handling of corrosive, abrasive and viscous fluids as well as those that must be transferred without contaminating the product. Vanton now offers the most comprehensive line of thermoplastic pumps in the industry.
Stay in touch
(+44) 01260 277040
Vanton Pumps (Europe) Ltd.
Unit 4, Royle Park
Congleton CW12 1JJ