Jun 20, 2003

Metals Plant Needs High-Purity Water

Application Requires Softening, Reverse Osmosis and Other POU/POE Technologies to Purify Water on an Ongoing Basis

Becoming the best at something takes focus. Dayton Progress
Corp.'s focus has been on manufacturing metal punches, punch blanks and
metal stamping tools. Located in Dayton, Ohio (one of six global locations),
Dayton Progress understood that it takes much more than precision cutting
machines to manufacture its tools and products.

It also would take experienced water treatment professionals
to ensure that the proper quality water was used in each process. That is why
it relied on Crown Solutions, Inc. to manage the point-of-use (POU) and
point-of-entry (POE) water treatment for each of its manufacturing processes
that required water. This hands-off approach allowed Dayton Progress to remain
focused on its products and on the needs of its customers.

One such manufacturing process requiring high purity water
is the Jetmachining Center (Omax Corp.) or "waterjet." The waterjet
is a computer-controlled precision tool that can create complex parts out of
most any material including metals, plastics and ceramics. The machine is
accurate within ±.003 inches and cuts directly from a CAD drawing. The
waterjet uses high-purity water delivered at high pressure and an abrasive
garnet to make precision cuts. The high-purity water is required for the
process and to extend component life. POU water is used to remove hardness
using a water softener, remove chlorine and chloramines using activated carbon
filtration, reduce total dissolved solids using a low pressure reverse osmosis
(RO) system and remove suspended solids using sub-micron filtration. Crown is
responsible for ensuring that the POU water meets the waterjet specifications.

Dayton Progress also has several electrical discharge
machine (EDM) wire-cutting processes that use water as a dielectric fluid. POU
EDM and make-up ion exchange tanks are used to ensure that the water is
nonconductive and gives maximum insulation. Crown Equipment Systems (a division
of Crown Solution, Inc.) continues to provide on-time replacement of these ion
exchange tanks. It also provides on-time replacement of EDM filter cartridges
(Ebbco). These reusable filters removed the suspended solids from the EDM
process tanks until the specified filter differential pressure (DP) is reached.
The filters then are replaced with new or cleaned filters and the dirty filters
are sent out to be cleaned. The filters can be cleaned four to five times
before replacement is required.

A POE RO system for coolant make-up water was used to remove
dissolved solids from the municipal water supply before it is distributed to
and mixed with the coolant in the sump of each process machine. The high-purity
make-up water extends coolant life, protects workpieces and tools from
corrosion and residue and minimizes bacterial growth in the coolant mixture.
Crown's preventative maintenance for the pretreatment and RO system
ensured that the equipment was consistently producing high-purity water.
Prefilters were provided to remove any suspended particles. Efficiency for the
RO operation is monitored continuously and membrane cleanings are provided as

In addition, the plant also hired Crown to be responsible
for treating the water used to cool the furnaces for the heat treating of metal
parts. Treating the water helps to protect all of the equipment and piping in
the system.

A closed process water loop is used to remove heat from the
furnace jackets. The process water is cooled in a plate and frame heat
exchanger, transferring heat to water running through an open cooling tower
loop. Finally, the water in the open loop is cooled by evaporation in the open
cooling tower. Crown implemented the use of soft water in the open cooling
tower loop to prevent scale in the cooling tower and heat exchanger. Using soft
water in the cooling tower allowed Dayton Progress to "cycle-up"
and reuse the water in the cooling tower without calcium scale issues. This
represents significant savings in make-up water, disposal and treatment
chemical costs. Both water loops are treated for corrosion protection and to
minimize microbiological activity. Corrosion coupons are used in both loops to
monitor the effectiveness of the chemical treatment program.

Dayton Progress worked with Crown because of its
"unique approach to water treatment." Crown provided a full-time
person not only to maintain all of the POU/POE water treatment programs but
also to manage the process waters, cooling tower chemical and blowdown systems,
closed-loop chemicals, MSDS program, wastewater treatment system and
environmental management program. Dayton Progress' water needs were able
to be met by one company instead of seven.   

About the author