TL-122

 

The Michoud plant demineralization

installation uses six Vanton vertical

sump pumps. Here, three acid pumps made

of Kynar PVDF are handling ambient H2SO4

at 20 gpm against a 55-ft. tdh. The

maintenance department replaced metal

pumps that experienced chronic downtime

due to corrosion.

Close-up of Vanton PVDF Sump Pump showing the epoxy painted metal motor mount and plastic protective coupling guard.

Thermoplastic Pumps Take

the Heat off Utility

INDUSTRY:

ENTITY:

SOLUTION(S) PUMPED:

PUMP TYPE(S):

Power, Energy and Utility

Entergy Corp.

Caustics, Sodium hydroxide, Sulfuric acid

SUMP-GARD Thermoplastic Vertical Pump

 

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Reprinted from INDUSTRIAL MAINTENANCE & PLANT OPERATION

 

Caustics and acids no longer cause maintenance

shutdowns

 

Entergy Corp. is a large investor-owned utility headquartered in New

Orleans and serving customers in Arkansas, Mississippi, Louisiana, and

Texas. As part of a cost-reduction and profitability program,

management began a planned program of reducing maintenance costs

through equipment upgrades.

 

A big part of the upgrade program is an attempt to reduce corrosion

problems and boiler downtime associated with pumping acids and

caustics needed for water purification.

 

At the company's Michoud Power Plant in New Orleans, water bills

average $6,000 a month. Boiler water consumes 100,000 gal. a day, and

another 25,000 gal. per day are needed for cooling, sealing, and

regenerating and rinsing resins. A demineralization system is used to

remove dissolved solids that remain in treated water.

 

Entergy uses sophisticated ion exchangers in the demineralization

system because water flowing into the once-through boilers must be

extremely pure. Removal of dissolved solids from the water prevents

corrosion and scale problems.

 

The ion exchange purification process is complicated, but one of the

keys to the process involves regenerating a resin bed that strips mineral

ions from effluent water and replaces them with hydrogen. This is

accomplished by using concentrated chemical solutions, which remove

the depleted ions from the resin bed and replace them with hydrogen

and hydroxyl ions.

 

Pump performance is critical to this operation. Handling various

concentrations of sulfuric acid and sodium hydroxide create

contamination and corrosion problems, which resulted in high pump

maintenance costs and excessive downtime. As part of the corporate

cost-saving initiative, the maintenance reviewed alternate chemical

pump designs.

 

The review prompted John Erwin, maintenance superintendent, to test a

vertical centrifugal thermoplastic pump on the caustic system. Erwin

chose the Sump-Gard® pump from Vanton Pump and Equipment.

The pump was required to deliver 20 gpm of 50% caustic at 108°F

against a 46-ft. total dynamic head. To handle this task. the Sump-Gard's

casing, flanges. impeller, vertical column and coverplate are made of

homogenous virgin polypropylene. Even the pump's 96-in. vertical shaft

is isolated from the solution by a thick polypropylene sleeve, and a

special shaft seal protects the bearing and motor from corrosive fumes.

Results of the test were excellent, and a similar pump was installed on

the acid tank. To handle the H2SO4 however, the material specified for

the wetted end and the shaft seal was Kynar® PVDF. This pump was

required to deliver 20 gpm of acid at ambient temperatures against a

55-ft. total dynamic head.

 

Because of the performance and service records of the two initial

pumps, John Erwin decided to replace all six metal pumps with

thermoplastic pumps manufactured to the same design specs as the

test units. In this case, Entergy's upgrade program paid off handsomely.

Each of these three Vanton Polypropylene

pumps delivers 20 GPM of 50% caustic at

108°F against a 46-ft. total dynamic

head.

The sulfuric acid and sodium hydroxide

required for the ion exchange

purification process is stored in these

large tanks outside the processing

building. Note the concrete containment

vault to catch any spillage.

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.

 

 

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(+44) 01260 277040

Vanton Pumps (Europe) Ltd.

Unit 4, Royle Park

Royle Street

Congleton CW12 1JJ

UNITED KINGDOM

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