Peltzer And The Merrill Co. - Dorr-Oliver Alumni

Merco History
(A Resume)
Peltzer and The Merrill Co.
Albert Peltzer was the inventor of the Merco centrifuge. He was born in Germany and came
to the U.S.A. as a young graduate of a technical institute. He immediately found
employment at the Waldorf-Astoria Hotel and eventually became Chief Engineer.
When Al Peltzer married, he took a honeymoon trip up the Mississippi River from New
Orleans to St. Louis. He liked St. Louis so well that he took a job there in a new corn wet
milling plant. The company was Corn Products, and he later moved to Chicago and
eventually was the chief designer for the coal-fired boiler and power house at their largest
plant at Argo, Illinois.
He became familiar with the whole scheme of processing and learned that a most expensive
and critical operation was the separation of starch from gluten. This was done by "tabling" in
large buildings filled with these bowling alley-like settling channels.
Mr. Peltzer believed that this operation could be done in a suitable centrifuge since the basis
for the separation was the difference in density of the two solid substances. He worked on
the idea at home in his basement, making drawings and small (4") models and doing test
work there. Eventually, in 1929, he had a centrifuge that would work, but after a brief in-plant
trial, his employer told him that they had no further interest.
At the same time, another engineer, Harry Coe, in California, was working on the problem of
separating gold from silica slimes. Mr. Coe had a contract with The Merrill Co., a venture
capital firm, and they filed patent applications.
These applications and Peltzer's came into the patent office at the same time, and the
principals, learning this, got together and combined their ideas. The Merco Centrifugal Co. was
formed in 1930.
It took two years to develop and sell workable units. The first (A series) were sold for mining and
drilling mud control. A second series (B) were higher speed units and were sold into the corn
wet milling industry. Sales grew slowly until after WW-II. In 1947 there were sales of a large
number of 30" I.D. Merco centrifuges and these proved highly successful and revolutionized the
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industry. Merco grew rapidly.
Dorr-Oliver Acquisition
In 1957, The Merrill Co. sold this entity to Dorr-Oliver, which was a larger equipment company
selling to a broader market. This encouraged further expansion.
The factory was moved to Hazleton, Pennsylvania, and the staff into the D-0 headquarters in
Stamford, Connecticut, and into regional sales offices.
Product Development
During the 1930's, Merco centrifuges were of the 16" I.D. size. This was considered large at that
time. All the units were made for handling large quantities of solids in round-the-clock production
plants. The centrifuges were designed to serve continuously for many years. This is still the
case.
After WW-II, most of the units sold were 30" I.D. size and nearly every unit sold since then is
still in full-time service. Some have revolved more than 25 billion times. (This compares with
the earth which has revolved around the sun about 4.5 billion times so far.)
After D-O acquired Merco, there was a spurt in new development work and new types and
sizes of Mercos were introduced so as to serve a wider market. This included versions for
high pressure (156 psi) and temperature (450°F), for liquid-liquid separations, for more
corrosive service, higher speeds, improved sanitation, and, most recently, our largest model,
which is now the Merco H-36.
The Merco H-36 is the largest disc-nozzle centrifuge in the world, and we have sold over
eighty of these thus far. We have had units in full-time service since 1974, and they have
proven very successful and most economic. In fact, their low Hp usage is a prime factor in
their selection.
In addition, we also now have a line of screen solid bowl centrifuges - the Mercones –
and a line of solid-bowl centrifuges the MercoBowls.
The broadening of our product line enables us to serve more markets and we thus learn
more about how to design and build equipment to satisfy diverse requirements. This, we
feel, means progress.
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Applications Development
We are learning something new every day. The wider our horizons have become, the
more we have been able to incorporate special design features and thereby perfect the
product. Changing technology and materials and methods makes this an everexpanding
frontier.
From our beginnings in food processing, we have worked with stainless steel and corrosionresistant
materials. As we developed applications in the chemical field, we had more severe
environments (sulfuric acid, phosphoric acid, mixed products salt solutions, caustic, tars,
solvents, products, waxes, explosives, etc.)
We also adapted out Merco centrifuges to effect counterflow washing, thickening, and
clarification, in addition to solids size classification and heavy media type separations. There are
instances of high and low viscosity, high and low solids percentages, stickiness, polymerization,
heat sensitivity, etc.
When we entered the field of municipal waste treatment, we encountered a whole new
environment of trash and carelessness, irresponsibility, and urgency and liability. We had to
effect many changes in our approach and in our scope of supply. In particular, we learned about
abrasive wear and how it has to be combated by both prevention and repair.
We have about one hundred units operating today under abrasive conditions we had not worked
against until ten years ago. We have had to design special screening and degritting systems,
internal and external hard facing, nozzle sleeves, special nozzle shapes, housing changes, etc.
we have also instituted certain installation and inspection practices and procedures. Finally, we
have set up an exchange pool of units and standardized charges so that repairs are done
economically and on a scheduled basis.
We believe that this history of invention and development places Dorr-Oliver and Dorcan in a
particularly well-suited position to serve the tar sands industry. We have the equipment and the
organization to be of significant service.