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Pumps Play Critical Role in Zero Discharge

 

Reprinted from Pumps & Systems

Ken Comerford

 

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

bicycle components.

 

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.

(Philadelphia, PA).

 

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

following advantages:

 

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

and re-used.

 

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.

 

Captions:

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.

Copyright 2016 - Vanton Pumps (Europe) Ltd - All rights reserved

About Us

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

mail@vantonpump.com

(+44) 01260 277040

Vanton Pumps (Europe) Ltd.

Unit 4, Royle Park

Royle Street

Congleton CW12 1JJ

UNITED KINGDOM

www.vantonpump.com