The World Of Positive
Displacement Blowers
A
Few Facts, Memories, and a Lot Of Nostalgia
By: Mark W. Royston
La Mirada, California
© 1999
It Began in 1859
The positive displacement blower was
first invented around the middle of the 19th
century. For those who are fastidious about
exact dates, they are referred to a historical
monument at the city limits of Connersville,
Indiana, the home of the Roots Brothers.
As was related to me by others, the
machine was first invented as a more efficient
water wheel. Made of wood, it was put in
the millstream and as the water flowed through
it, the rotors turned and power was generated for
milling from the output shaft. It worked
well except for a minor flaw; the wood would
swell up and ruin the clearances and the mill
would stop. The unit would be taken out of
service and dried out, shrinking the parts to
their original dimensions.
In an effort to speed up the drying,
as soon as the rotors would turn, a power source
could be connected to the output shaft and the
rotors spun. Someone noticed that such an
arrangement would move a quantity of air and the
use as an air blower was begun. Over the
years the liquid pump version has persisted and
today there are versions of the positive
displacement liquid pumps in operation.
They are used mainly as transfer pumps to handle
large volumes of liquids at moderate
pressures. In their simplest form they
could be considered as a “two tooth”
gear pump.
First Blower
Application
The first air
application was as cupola blowers. While
the pressure requirements were low compared to
today’s needs, the positive displacement
blower’s ability to supply a constant volume
of air over a varying pressure range made it
ideal for the purpose. Another early and
interesting application was as an air source for
player pianos and large organs. As time
went on the positive displacement blower gained a
good foothold in industrial applications,
replacing the centrifugal blower on its high end
and the compressor on its low end.
The engineering of
applications was simple. While the
horsepower requirements of other air moving or
compressing devices varied with the inlet
pressure, temperature, or gas density, they did
not with the positive displacement blower.
The horsepower was a function of the displacement
volume times the differential pressure.
While variations in these conditions might change
the volumetric efficiency of the blower, the
horsepower formula didn’t change. As
time went on, this would make the positive
displacement blower ideal for certain
applications.
By 1930 there were
three blower companies in existence in
Connersville, Indiana: The Roots Blower Company,
The Connersville Blower Company and the
Wilburham-Green Blower Company. In a rash
of consolidation rare in those days, they decided
to quit fighting for business and join each
other. For a period the amalgamated mess
was known as the Roots Connersville Wilburham
Green Blower Company. After a period, it
became, as it is known today, the Roots
Connersville Blower Company.
How Sutorbilt
Came About
The merging of the
three companies was responsible for the formation
of another. As one might guess, sales were
made through Manufacturer’s Representatives
and there was one for each company in most major
cities. Now that they were one, there was
need for only one representative. The
merged companies made a move in the Los Angeles
area that would haunt them from that day
forward. One of the representatives
let go was the W.F. Sutor Company. William
“Bill” Sutor was a well liked
representative in Southern California that
handled such varied lines as Dongan Electric, and
Atlas Car and Manufacturing Co. The positive
displacement blower business was a growing one as
the chemical and petroleum plants began to make
the L.A Basin and the High Desert a good outlet
for blowers.
One of the employees, Robert S.
Clark, was a Naval Academy graduate, Class of
’26. He had retired from the peacetime Navy
and was engineering and selling for Mr.
Sutor. Later he would become the owner as
Mr. Sutor suffered from Parkinson’s Disease.
Original Equipment Manufacturers
(OEM) were rare but there was one in Pomona, the
Brodex Company. They manufactured a line of
paving machines that needed to burn crude oil to
generate the necessary heat to process the
asphalt. Every machine made needed a small
positive displacement blower to atomize the
oil. While the size was small it did
represent a predictable volume.
W.F. Sutor Company also had a
machine shop. They were in the business of
“re-grooving” flat belt pulleys to the
recently invented “V-Belt”
drives. They also fabricated and
machined oil well pumping jacks. While the
machine shop was not large, it was capable of
machining castings of an item, such as, say, a
blower.
First Sutorbilt
Blower Sale
Brodex was
approached with an idea. If W.F. Sutor were
to manufacture a blower, would you buy it?
The answer was, “yes, if it
works.” Thus W.F. Sutor was in the
positive displacement blower business. Now
1930 was not the time to be in any business, let
alone a new manufacturing business. Two
things saved them, the Repeal of Prohibition and
World War II.
When Prohibition
was repealed most breweries were in a sad state
of disarray. When they were rebuilt,
modernization led them to adopt a new method of
grain handling. Out of Europe came the
pneumatic conveying method of material
transfer. While it was not as efficient as
mechanical methods, such as drag chains, and
bucket elevators (Remember, the front end loader
hadn’t been invented.), pneumatic conveying
allowed the source or pickup point to vary (using
a vacuum pickup) and the discharge points to be
switched by the use of pipeline diverter
valves. A messy operation became a clean
one.
Other
applications became evident and shortly many
pneumatic conveying applications became
evident. While Roots controlled the larger,
more status minded companies, Sutor became quick
on its feet and learned the application
engineering necessary to recommend blowers to the
pneumatic conveying industry. In the
thirties only a few companies were in the
pneumatic conveying business. Most had
backed into it because of other uses for their
products.
The largest of
these pneumatic conveying companies was the
Fuller Company, in Catasauqua, PA. Colonel
Fuller was the majority stockholder of the
Allentown Portland Cement Company. The
cement industry needed a company to engineer
products that would meet the challenges of the
abrasive environment of its manufacture. He
created the Fuller Engineering Company for that
purpose. By the thirties, it was well
entrenched in the art of pneumatic conveying in
the cement industry. The cement conveying
varied from the grain handling in its pressure
requirements. Since cement was abrasive,
the method of introducing it into the conveying
line varied from that of the grain handling
systems. One of the breakthroughs came from
the invention of the Fuller-Kenyon Pump.
This device used a screw to push the cement into
the conveying line where it would be carried away
by the air stream. Since the air also
wanted to take the path of least resistance, a
method had to be found to keep the air from
escaping back through the product input.
The Fuller-Kenyon Pump solved this by varying the
flight of the screw, so that the first part of
the flight wanted to handle more than the later
parts. This compressed the cement into the
barrel of the pump and created its own seal.
Cement could be
conveyed at lower velocities than other products
and because of its finely divided particles, it
would take on the semblance of a liquid, as it
was pushed through the pipeline. (Today,
this would be known as dense phase conveying,
while the handling of products with larger
particles would become known as dilute
conveying.) The cement was carried for long
distances and a compressor was needed to provide
the air power. Pressures were up to 30-35
psig and well beyond the capabilities of a
positive displacement blower. Reciprocating
compressors were available, but were normally
used in higher-pressure applications. (Such
as plant air supplies.) The search for a
compressor to match the Fuller Kenyon Pump led
Fuller to France and the rotary compressor.
As it was manufactured in France, it used thin
steel blades to separate the rotating cavities as
the eccentricity of the rotor from the cylinder
compressed the air as it rotated.
Most of the dams
that were built as public works projects in the
thirties had Fuller-Kenyon pumps that would
transfer cement for miles from the cement source
to the dam site. (Other products for
the cement industry were a part of Fuller, but it
is the pneumatic conveying that matches it with
the positive displacement blower
industry.)
W.F. Sutor gave
their blower the name of Sutorbilt. Early
advertising slogans were “Sutorbilt is well
built” and “Go there for
air.” As their manufacturing
increased, the attention to the Representative
business fell off. They added to their
product line, items that were needed to complete
a pneumatic conveying system. (If the
conveying companies wouldn’t buy this new
fangled blower, then Sutor would build complete
systems.) By the end of the thirties, Sutor
was the authority on the handling of the more
nasty products such as cotton seed, (both
linted and de-linted) cottonseed meal, cottonseed
hulls, wheat and grains. They also built
large portable systems that were used to unload
Copra (dried coconut meat) from ship holds.
Many of these operated in the ports of Los
Angeles and San Francisco as well as at such
manufacturing plants as Proctor and Gamble in
Ivorydale, Ohio. Each of these products had
characteristics that made them difficult to
handle, but Sutor endured and fought them
through.
World War II
When World War II
started, all manufacturers of positive
displacement blowers were called to the war
industry. The need was for vapor
compressors. Each detachment of soldiers
and each ship needed dependable fresh water to
carry on the war. The solution was a “water
still” and the most popular one was one that
created fresh water using a partial vacuum to
reduce the boiling point of the liquid. The
water was heated and a vacuum created by the
“vapor compressor” pulled off the
steam, which was then condensed into fresh
water. This process was called the
Kleinschmidt cycle and the vapor compressor
was a modification of the positive displacement
blower. Outboard bearings and stuffing
boxes were used to isolate the bearings from the
steam. The materials of construction were
bronze or Naval Brass. Besides Roots and
Sutorbilt, General Motors came in as a supplier
as they had developed a line of positive
displacement blowers used to supercharge large
engines. Vapor compressor sizes were
tailored to match the needs of the
“still” manufacturer. Thus odd
ball sizes and gear diameters were common.
War’s end
found Sutorbilt with a lot of bronze on
hand. Parts were going through and all of a
sudden the orders stopped. The government
called a halt to the orders, paid them for work
done and they could do with the vapor compressors
as they wanted. A lot of these bronze beauties
found their way into industry, with no thought of
the difficulty to match them to standard sizes as
replacements were needed. Actually the war
surplus “stills” created a new
industry, that of “mountain quality”
fresh water. Companies sprang up who
purchased the war surplus “stills” and
water which never saw the mountains was distilled
and sold as mountain water. Minerals could
be added, salt content controlled and water could
be produced to specifications not attainable from
the melting snow and footprints of men who trod
the mountains.
Two companies
continued to produce these stills, one in New
Orleans and one in Waukesha, Wisconsin.
Later offshore drilling rigs and other remote
exploration sites continued the demand for the
water stills.
Vacuum to
Increase Oil Production
Somewhere in the
thirties and forties the “well vac”
came into existence. The Los Angeles basin
was filled with oil under the ground.
Southern California areas such as Signal Hill,
Santa Fe Springs, Tonner Canyon, Coyote Hills,
South Main Street and the West Side were
pumping oil at an expanding rate. As some
of the wells were depleted, it was found that
pulling a vacuum on the casing could increase the
output. A positive displacement blower was
just the answer. In addition, a salesman
worth his weight would be remiss in not
mentioning to the adjacent oil site that his
neighbor had installed a well vac and its
influence might, just might, extend beyond his
boundaries and pull up a few barrels of his
neighbors oil. Thus a steady sale of well
vacs was assured.
Fuller Company
One of the First Pneumatic Conveying Companies
In 1949, the
Fuller Company bought a company in Cleveland
known as the Draco Corp. (Dust Arresting
and Conveying Company) This is mentioned
only because they had a line of inferior
airlocks. (An “inferior” airlock
was one manufactured by someone other than the
Fuller Company.) Later on when Fuller
bought Sutorbilt, the Sutorbilt line of Airlocks
was discontinued, as Fuller had no need for two
lines of “inferior” airlocks. (If
one would take a real close look at early
editions of the airlocks made by Wm. W. Meyer and
Sons, one would note the sameness of their design
and dimensions to the Sutorbilt airlock as theirs
was placed on the market shortly after the ones
at Sutorbilt were discontinued.)
By the early
fifties, the Sutorbilt machine tools were getting
tired. Impeller contours were still ground
by hand to matching sets. There were three
or four persons who did nothing but grind
impellers. By this time Mr. Clark owned the
large majority of the business as
Bill Sutor had left the business in 1946.
The blower
industry was never at a loss for new
applications. Well before my time in the
late forties an inventor came into town from
Minnesota. He had invented an
“Isomagic” ice machine that he could
sell to every bar. Imagine, ice cubes at
your demand, pure and clear. The clear part
was the significant word. Everyone knows
that each commercial icehouse uses an aerator to
bubble the air through the ice as it freezes to
insure clarity. Lots of positive
displacement blowers were sold for this
purpose. Our Minnesota friend had a patent
on the process and needed a lightweight blower to
solve his aeration problems. Since the
pressures were light a new series blower with
aluminum parts and a 2-½ inch gear diameter was
designed and produced. Some 250 unusable model
2520 aluminum blowers began to gather dust on the
shelves as the venture failed. Since the
aluminum parts limit severely the pressures at
which a blower can operate, there they sat,
a monument to the “Isomagic”
venture.
The Uranium
Craze
The Cold War came
to the rescue. The search for Uranium
created a craze, not heard of since the
‘49ers poured across
“Californee” searching for gold.
The deserts of California, Arizona, Nevada and
Utah crawled with uranium miners searching for
that elusive element that until a few years ago
was described in the dictionary as “a
useless metal, not found in the U.S.”
Geiger counters were at the ready as a mass
movement not seen since the “gold rush”
days of the unemployed of the Great Depression
made its way across the deserts. Once a
find was made, the claim could be staked
and then “proved.” The proving
was the tricky part. A core sample needed
to be taken and given to the assayer. How
to get the core sample was the problem. The
typical core sampling was done with a wet
method. There was no water on the desert
and thus the need for a dry recovery method.
Enter the scene a
gentleman from the remote Simi Valley.
Reese Houston was his name although we promptly
rechristened him “Sam” (The name
“Sam” stuck until finally he changed
his legally.) Sam had an idea.
A two man pack operation that would carry the
core driller and the core remover. All
powered by a chain saw engine. Not a bad
idea. He had the core driller working well.
All that was left was a small lightweight vacuum
to suck out the cuttings. Lightweight
struck a chord. Why not try the Isomagic
blower that only weighed 12 pounds. After
all there was no way he could use up 250
blowers. We magnanimously loaned him a test
blower and off he went. Well, what do you
know? The damn thing worked. It
worked so well that he used up all 250 of the
nice lightweight blowers and was asking for more.
Since I was the one who had
come up with the bright idea to use the Isomagic
blower, the plaudits turned to boos as production
wanted nothing to do with any more lightweight
aluminum blowers. It fell to me to tell Sam
that the blower on his backpack now weighed 32
pounds rather than 12, and to add a double
Whammy, we wanted more money for the
insult. Sam was finally mollified, although
it took a number of trips to that remote Simi
Valley that, to that time, showed no signs of
development and the only road in was a narrow
two-lane highway through the Western town of
Corriganville. (Remember Wrong Way
Corrigan?) The Houston Tool Company went on
to use a lot of blowers including some large ones
that were used to suck up the cuttings after
A-bomb tests in Jackass Flats, Nevada.
Finally the Uranium craze died down and Sam rode
off quietly in the West. Actually he
didn’t go too quietly as he was helped along
by his creditors.
The Cold War
and Bomb Shelters
As was, and is,
typical of the blower applications, one rises,
another falls and you remember with nostalgia the
“good old” applications. I
can’t leave the Cold War without talking
about bomb shelters. When it was obvious
that we were going to be bombed back into the
stone age, it was decided that the positive
displacement blower industry would be the first
to crank out the stone age machinery.
What does every bomb shelter need? An air
source! What doesn’t every bomb
shelter have after the big one?
Electricity! If you need air but don’t
have power, that only leaves one answer, a hand
operated blower. Both Roots and Sutorbilt
rushed one into production, with Roots
being a bit smarter than Sutorbilt. They
thinned down the gears, opened the clearances and
put in thin oil. Both had a crank handle
and a speed up drive that brought the little
monster to a performing speed. You’ve
heard the phrase, “Only the strong
survive.” Well, that would have been
true with the hand operated Sutorbilt blower
turner. The power that would have been
needed to keep that blower turning would have
taxed the strength of a Charles Atlas (To
keep the comparisons in line with the date.)
Off both companies
went to the trade shows that were replete with
all kinds of survival gear. Both showed off
their new product and luxuriated in the sweet
nothings of, “You’ll need 40 acres just
for the parking as everyone in the country
will need one of these babies.”
Of course, Sutorbilt had to send a larger crew to
the show, as they took turns keeping that life
saver up to speed, while they cursed the designer
that settled on standard industrial parts and
clearances, while all the time keeping potential
customers from trying to turn it themselves.
What was good for
the world, Peace, prevailed and the bomb shelter
business bombed and this was also good for the
blower industry, as the funeral dirge for the
bomb shelters was heard before 250 of those
little, never to be sold, energy burners were
placed on the shelves.
Blower Designs
A little bit about
blower designs. Early blower designs had
sleeve bearings. This was an acceptable
bearing surface, but since sleeve bearings wear,
the impeller assemblies would drop and contact
the lower case. Cases for larger blowers,
for the most part, were made in multiple
pieces. They would be rough machined and
then machined as a set. Final assembly
called for two half cases connected with top and
bottom plates. While the machining was
labor intensive, the assembly allowed for precise
tolerances to be set. This made for very
efficient blowers that were later hard to
duplicate as more precise machining methods and
faster assembly requirements called for opening
the clearances.
Up until 1956, maximum blower speeds
were very slow, somewhere in the 1600 Feet Per
Minute gear speed. If requirements dictated
higher speeds (such was needed in the Aerospace
Ground Support Business), dynamically balanced
impellers were added and maybe a thrust bearing.
While small blowers had “spur” gears,
larger blowers had “Herringbone
gears.” If a thrust assembly was
required, a spur gear unit had two internal
thrust bearings, while Herringbone units only
called for one. Many larger units had up to
eight bearings which included four main bearings,
double outboard bearings, located in the gear
case on the outboard side of the gears, a single
outboard bearing outside the drive sheave, and
the ubiquitous thrust bearing.
Just listen to the instructions for
setting the thrust bearing. “Turn
blower on and operate at normal speed.
Using a wrench, turn the adjusting screw on the
thrust bearing clockwise. Continue until
the blower ‘hesitates.’ Turn back one
full turn and lock the setting.”
I don’t know about you, but I was never
about to turn a thrust bearing set screw until
the impellers ran into the head plate. (I
would leave that to some pro like Johnny Salser,
the main service man for the company.)
How Blower
Series Got Their Names
The naming of
blower series didn’t use a lot of
imagination. The small blowers made by
Roots were called the “AF”
series. That, of course, stood for
“anti-friction,” as in “ball or
roller bearings,” compared to the older
design of sleeve bearings. The large sizes
were still a sleeve-bearing machine called
“RCDH,” for “Roots
Connersville” and a corruption of
“Heavy Duty.” When Roots came out
with their larger roller bearing machine, it was
called the RCR series. The same Roots
Connersville applied and the second “R”
stood for “roller bearings.”
Clever, Huh! The actual size of
the Roots blower was an indication of the gear
diameter and the impeller length, in
inches. Thus a 45AF was a unit with a
4-inch gear diameter and a 5-inch case
length. This naming of sizes went from
their smallest to their largest, except for the
two smallest gear diameters. The 2 ¾”
gear diameter was just “2” and the 3 ½
“ gear diameter was “3.”
Sutorbilt,
generally followed the same naming of sizes in
the larger units but deviated in the smaller
sizes (Two through eight inch gear diameter) by
having a number to indicate gear diameter and a
letter to indicate low “L”,
medium-“M”, or High-“H”
pressure ratings. Actually it
was not unusual to make the units in
“odd-ball” case lengths to fit a
specific requirement. From an engineering
standpoint, naming the blowers by gear diameter
and impeller (or case) length was good, because
if one knew the gear diameter and case length of
a blower, the displacement could easily be
calculated and its performance laid bare.
Sutorbilt named their smaller blowers the
“California Series” to add that Sunny
California mystique, as they tried to capture a
part of the Eastern market.
Sutorbilt
Corporation Sold to The Fuller Company
In late1955, Mr.
Clark sold the business to the Fuller Company,
who were in turn owned by General American
Transportation (The GATX you see on railroad tank
cars). While the marriage might be
easily accepted as a good match between Fuller
and Sutorbilt, because of Fuller’s need for
positive displacement blowers in pneumatic
conveying, what in the world is the connection
between rail cars and the Fuller Company.
Well, it all
turned about a product called the
“Airslide.” Fuller Company had
patented an item whose generic name was an
“air activated gravity conveyor.”
Actually their patent didn’t cover the
entire concept, but the porosity of the belting
upon which the product slid. It had been
discovered that certain products, such as cement,
would easily aerate and if you poured cement in
on one end and pushed air up through the belting
(another use for a positive displacement blower),
the fluidized mixture would flow, like water,
down a minimum slope. Cement plants
throughout the country rushed to put in this new
method of transferring cement through their
plants.
After World War
II, there was a move to modernize the method of
transferring cement by bulk. Fuller Company
and GATX started a joint venture to design a
railroad car that could haul a large payload and
be automatically discharged at its
destination. The result was the Airslide
railroad car. Before it was through, in the
late forties, General American bought out Fuller
Company. Later on, the Airslide car
became the staple for handling bulk flour and
other products as well. (The bulk truck is
another story.)
Blower Quality
Is Improved
The work to
improve the quality of the blower
continued. The first operation that needed
attention was the impeller profile. The old
and expensive method of grinding the contours was
to be discontinued and replaced by a pure
machining operation. Cutting tools would
machine one side of each impeller in a single
cut. There were many engineering meetings
to determine the best profile for the impeller
and finally a “modified involute” was
chosen. This was the easiest to machine and
allowed the throat of the impeller to remain
un-machined because by the time the impeller tip
had entered the throat of the mating impeller, it
had begun to seal in the other face of the
impeller. While this design simplified
manufacturing, it did lead to some broken shafts
and other damage in those applications where
there was an inordinate amount of liquid in the
air or gas stream. (If your curiosity is
aroused as to why this happens, this design makes
for a changing of the volume in the throat area
as the impeller rotates through its circle.
If there is a solid amount of water present, its
incompressibility can lead to major damage to the
blower.)
The Move Toward
Increased Speeds
About this time in
1956 and 1957, there was a horsepower race that
began in the blower industry. To this time,
the blowers were operating at low pressures and
low speeds. Roots came out with a blower
design that was called the RAS
(Roots-Air-Segmented impeller) and RGS
(Roots-Gas-Segmented impeller). These
blowers ran at the unheard speeds of 3000+ FPM
gear speed.
Actually
“unheard of” is a poor choice of
words. The old pleasant
“chug-chug” of a blower operating was
replaced by a scream that could be heard
throughout the user’s plant and into
backyards two miles away. The blower became
a low frequency noise generator and the only ones
smiling were silencer companies such as Burgess
Manning and Universal Silencer. Combine
this with the new government agency called OSHA
and there was a rush to find the best type of
silencer to do the best silencing. The best
design turned out to be a combination
chamber-acoustic type that used the chambers to
reduce the pulsation and the acoustic material to
reduce the noise coming off of the silencer
itself.
Sutorbilt designed
a matching blower for gear diameters of 10”
and larger, calling it the 3200 series (named for
the maximum gear speed of the unit.) The
smaller blowers in the California Series came in
two varieties; one at the old series speed and
one at a higher gear speed with dynamically
balanced impellers and a small drive shaft
mounted thrust bearing. (This high-speed version
became known as the California Series
“B”.) The thrust bearing was of
doubtful value as it limited the space available
for the drive pulley. Some dimensional
changes were made but kept to a minimum, so that
replacements of old blowers could be easily done.
An Unusual
Application
One of the OEM applications that took a
modified 5L was the laundry press blower. A
company in Utah had designed a faster and
improved laundry press that used a positive
displacement blower to draw off the hot steam and
cool the shirt. The result was a quicker
process and a better-looking shirt. Five to
ten 5LS blowers made their way to Salt Lake City
each week. (The “S” on a model
always indicated something special and the need
to look at the original manufacturing card for
that serial number.)
The Growth of
Bulk Flour Handling
One of the major industries
that took flight in the fifties was the bulk
flour milling and distributing. Until that
time milling companies sacked off their products
into 100-pound sacks and the sacked flour was
then shipped off to the bakery or consumer.
It was found that flour was one of easiest
products to convey through a pneumatic conveying
system and a new industry was begun.
Companies specializing in flour handling sprang
up in the Mid-West from Minneapolis to Kansas
City. Since Mr. Clark and Bob Schneider
were busy with their old customers and sales
routes (which would take them to such industrial
metropolises as Lake Louise and Banff), the
servicing of these new customers fell on the
shoulders of yours truly. A typical trip
would be to Minneapolis, Kansas City, Salina and
Wichita. A lot of life long friends were
made as companies such as Flo-Tronics, Semco,
Superior Separator, Salina Manufacturing, and
Shick Tubeveyor came into being. (It is
well remembered a conversation in a coffee shop
in Kansas City, Kansas with Bill Ungashick that
maybe helped to convince him that he should quit
as chief engineer of Crissey Company and start
the highly successful Shick Tubeveyor .)
Some of the first bulk
flour trucks ran out of Salina, Kansas under the
name of “Econoflo”. The actual
owner of the company was Gooch Feed Mills, an
extremely large milling operation owned by the
Vanieer Family. Their chief engineer and
general manager was a gentleman named John Landis
and he appreciated someone coming all the way to
Salina from California so much that he purchased
nothing but Sutorbilt blowers. Not
only that but he would place his orders with no
one but Royston personally. A cell phone
would have come in handy in those days, as a lot
of time was spent out of the office.
The beauty of it all was
the education received. As the pneumatic
conveying engineering went from the “I hope
it works,” to “I think it will
work,” to “I’m damned sure it will
work,” Royston was absorbing all he
could. Add to this the work in the dirty
cotton gins and oil mills that was shoved off to
the junior member and it wasn’t long before
the knowledge of pneumatic conveying in the
company was beginning to default to this same
junior member.
Aircraft Ground
Support Equipment
Other applications were
found in the Ground Support equipment for both
the military air bases and commercial
airports. During the late forties and early
fifties it was an industry that would support a
salesman to cover those applications. There
was pressure test equipment that would check out
the airplanes piping systems for leaks.
There were ground air conditioners that would
supply refrigerated air to keep the electronic
equipment aboard cool (replacing the ram air that
was introduced when the plane was in
flight.) Many of the jets required a large
airflow at pressures in the 15-18 PSIG to start
their engines. One of the first jet
starters was supplied by Sutorbilt and consisted
of a double staged unit with blowers in the 12-14
inch gear diameter. The unit was on wheels
and it almost dwarfed the airplane it was
starting.
The largest application for
positive displacement blowers in the Aerospace
field had to be the ground air conditioner.
The specifications called for 100 pounds per
minute airflow at an outlet pressure of 3 PSIG at
the end of the hose. Add to the package a
25-30 ton refrigeration air compressor,
condensers, evaporators, portability and such and
you have a somewhat sophisticated package.
Many thousand of these units were built, but the
first production order for thirteen units, was
built by Sutorbilt in late 1954. The blower
was an 8L running at its normal speed to put out
around 1250 CFM. The refrigeration
compressor was a brand new designed York
“Vee” series. Why do I know so
much about these units? I was the service
man who ended up at the Douglas Aircraft plant in
Tulsa Oklahoma when they didn’t work.
That was the longest three weeks I spent in my
life. I was sent off by Mr. Clark
with the instructions that the units needed a
little adjustment. A screwdriver and a
quarter inch drill should be enough tools to take
care of the project. Might take two or
three days.
When I was met in the lobby
by the chief maintenance manager and the vice
president of manufacturing, somehow I sensed
there was something more amiss than a few
adjustments. Somehow the damages received
in shipment (created by the failure to properly
tie down the units on the transporter) paled into
insignificance as they got to the main
point. The damn things just didn’t
perform. The air was supposed to be at
around 33-34 degrees leaving the hose and
entering the airplane. The actual
performing temperature was around 45-50
degrees. Quite a difference.
Knowing nothing about refrigeration and at that
time little about blowers (I think I had been on
the job at Sutorbilt less than six months), as
soon as I could get out of the line of
fire, a call to Mr. Clark was made and it was
explained that he had obviously made a
mistake. Not only did they need the most
capable person in the plant but they wanted to
talk to a corporate officer as the mention of a
lawsuit came up in every other sentence.
This was my first indication that Mr. Clark was a
“sandbagger” of the first degree.
He knew what the problems were. He just
didn’t want me to know until I was in the
fire up to my elbows. He admonished me
with, “If you want me to have some calling
cards printed that says
‘vice-president’, I’ll do it and
send them to you. Meanwhile get back at it
and take care of the problem.”
Somewhere in the back of my
mind was the remnant of marine engineering
courses and psychometric charts. A trip to
the library in the evening brought me up to speed
so that I could at least follow along in the
conversation. After some calculations were
made the light dawned. There were two
conditions to be met; one called the
“design” conditions and the other
called the “overload” conditions.
We had tested at the overload conditions and
assumed that if the units met that, we would have
the design conditions “cold turkey,” so
to speak. Turns out the design
conditions were much harder to meet, with the
overload conditions put in just to insure that
the units would physically function at the tarmac
temperatures that existed in that tropical
climate known as Tulsa, Oklahoma. It took
about three weeks before it was able to get the
units to operate somewhere near
specifications. Refrigeration suction
pressures were adjusted to get the most out
of the system. Speeds of components were
fine-tuned and finally Douglas Tulsa bought them
off. I was able to go home after a three
week on the job training in refrigeration
systems.
These were the last
complete units built for this service by
Sutorbilt. After that they were content to
vie for the bare blower business and let others
more skilled in the refrigeration end, build the
complete package. Just about this time a
third blower company was showing signs of being a
competitor. A Company that came to be known
as the Mehiele-Dexter Company (Later to be known
simply as MD Blowers) started competing for the
aerospace business. They built a blower
that had three lobes instead of two. While
this cut down on the displacement of a given
size, the thicker throat allowed them to operate
at much higher speeds with the resulting smaller
overall size. Their price was right and
those jobs were bought on price. Sutorbilt
competed with them successfully in the early days
but finally gave up the declining aerospace
market to them. This was helped along by
the decision of the new owner, Fuller, to
standardize on product lines and to build no
special blowers. The aerospace market was
rife with specials and it wasn’t unusual to
see blowers with shafts extended through the gear
case to drive hydraulic pumps. Special
flanges to match the standard motor NEMA
“C” faces were common.
Bulk Cement
Trucks
MD Blowers weren’t
taken seriously as a competitor until they tried
to make inroads into the growing pneumatic bulk
truck market. Bulk feed trucks had started
in the East and represented a good market for
blowers. A company called Sprout Waldron
expanded their feed milling equipment by
producing a bulk feed truck that would deliver
feed from the miller to the farmer using the
feed. The trucks would blow the meal into
small storage silos located at specified points
around the farm. Sutorbilt had adapted a
model 7H for this application. (They added
an aluminum gear case as a token weight
saver.) Sprout Waldron would issue orders
in the hundreds of blowers and they and the
Middle Pennsylvania Sutorbilt Representative,
were very happy with the arrangement.
When the bulk cement trucks
started to appear, there were a myriad of
designs. Sutorbilt continued to offer the
7H blower, ala “Sprout Waldron”, for
this new industry as well. One of the
considerations given to the truck size was
weight. One of the major haulers out of
Wisconsin didn’t even carry a spare
tire. (Hell, the driver had to call an
expert to change it anyway.)
The evolution of the design
for a bulk cement truck is worth noting.
Fuller Company and Fruehauf Trailers went
together to design a bulk cement truck.
After all, the Airslide railroad car was the
standard in the industry. Fruehauf sent an
engineer to live at Fuller and while one supplied
the pneumatic conveying expertise, the other
would make the entire product roadworthy.
As they slaved away, there was another Fuller
engineer who came up with an idea for a
small-containerized product to hold and convey
drilling mud to the burgeoning off-shore
drilling rig market. This little jewel was
called an “Airslide Pump” and when he
took it to the powers that be at Fuller, they
patted him on his head and said that it showed
promise and that they would put it in the
catalog.
Along came a fellow from
Baton Rouge by the name of Tom Nix who just
happened to see this design for the Airslide
Pump. Delta Tank, Tom Nix’s company
was in the business of supplying equipment to the
off shore drilling rigs as well as manufacturing
low pressure propane trailers. Stopping
just long enough at Fuller Corporate to get a
license to build portable and stationary Airslide
Pumps, he returned to Baton Rouge with an
idea. He took one of his liquid
propane trailers and welded an Airslide section
in the bottom. The Airslide Pump part of
the design allowed the aeration air coming up
through the belting to be collected and become
the source for the conveying air. The
system was designed to operate under 15 PSIG to
keep the trailer from being considered as a
pressure vessel. The secondary asset to
this design was that a positive displacement
blower could operate up to that
pressure. In a two week period, Tom Nix
introduced to the cement world a brand new
design of a bulk cement truck and the first order
was for 150 trucks to this same Wisconsin Trucker
that disdained the carrying of a spare tire so
that weight could be saved.
Meanwhile, Sutorbilt, who
had been supplying blowers to Delta Tank for
their off shore drilling equipment, now found
another application. Every one of these
trailers needed a blower. Let’s trot
out the 7H and make that a standard. That
baby weighed in at 435 pounds and after all, it
had an aluminum gear case. What more could
a customer want? A bit more it turned
out. Get rid of the spare tire. Who
wants to haul around a 435-pound dead weight that
is only used for a half-hour or so at the
destination to unload the cement. Standing
over to one side was MD Blowers, waving their
arms and saying our product only weighs 285
pounds. Where Roots created the speed race
a few years before, MD started the weight
reduction craze. Before it was through,
Sutorbilt built a new series blower (the 88
Series) that had lots of aluminum, very thin head
plates and a whole lot of maintenance problems.
The Series 3000
Another series that came
into being in the late 1950’s was the series
3000. This was a group of blowers limited
to one gear diameter, eight inch. The need
for this was created by the way Roots had
designed their series. Their small series
was limited to a maximum of a seven-inch
gear. Eight inch and larger were built on
the larger series design. Sutorbilt’s
small blower series went through eight-inch gear
diameter. Since the smaller series operated
on a different set of design parameters, their
eight large blowers would out perform the
Sutorbilt eight-inch small blower design.
Sutorbilt’s answer was to add a new series
to the line that would almost perform to the
design capabilities of the large blowers.
(3000 FPM gear speed versus 3200 FPM gear
speed.) This proved to be a very popular
machine as it was easier to build than the large
units. (It had no force feed lube pump and
the timing gears were secured by the use of a set
of “grip rings”. This made for
easy timing at the factory level but was a bit
disconcerting to the non-pro out in the field.)
Pacific
Pneumatics
Pacific Pneumatics started
on a true shoestring. Operating out of the
house, it was a one- man sales force and a
bedroom was designated as an office. A
couple of extra lines were brought in and
telephones hung from the wall within easy reach.
Principals were not easy to locate as they all
had a certain reticence about signing on with a
true unknown. Finally enough signed on to
make it a respectable list and we were off and
running. Before the year was out, we had
Sutorbilt for the San Joaquin Valley and the
Imperial Valley. That pretty well covered
the cotton seed industry except for one mill in
Vernon. Propellair Fans and Universal
Silencer were the first to sign on, followed by
Fuller Compressors, Lehigh Fans and Peterson
Filters in ensuing years.
From the beginning,
fabrication played a part of the operation.
Sutorbilt had for many years fabricated anything
to which they could tie a positive displacement
blower. Once they decided to concentrate on
blowers only, they wanted to shift the
fabrication of those special items to someone
else, while selling the blower that would be the
heart of the package. The first Pacific
Pneumatic sale was such an animal. An
inquiry came in for an oil tool sump cleanout
unit from Hughes Aircraft. They needed one
just like one Sutorbilt had fabricated some years
ago. Sutorbilt even donated the shop
drawings. A local fabricator, Holzinger
Bros. Sheet Metal, was found and the bid was
made. It was during this time that the use
of a name rather than that of an individual was
appreciated. The purchasing agent, in his
best buying pose, wanted to know how much we
could cut the price to get an immediate
order. It took all the courage possible to
stand pat and say, “I just sell these
things, I don’t set the price.”
The buyer sighed and fished out a Purchase Order
and Pacific Pneumatics had its first
sale.
Learning New
Terms in the Rep Business
Moving from the world of
positive displacement blowers into one where fans
and compressors were involved meant learning new
concepts and markets. The business was
built around the PD blowers but now things like
“velocity pressures” and “static
pressures” crept into the conversation as
new customers and contacts were made for
Propellair Fans. Propellair was a division
of Robbins and Meyers and manufactured a line of
industrial ventilation equipment that included
wall fans, powered roof ventilators and space
heaters. It was interesting to see how
companies like Robbins and Meyers diversified in
the “Olden Days.” Robbins and
Meyers was a manufacturer of electric
motors. Manufacturers of other products
most often needed a motor to drive their
equipment. Many of these companies operated
on short capital and needed generous credit terms
to continue to operate. It was a policy of
Robbins and Meyers to give very generous terms to
their customers. This cemented relations
that insured the continuance of that
customer. In many cases the cementing
turned to concrete as the company, unable to pay
their bills to R. & M., ended up being owned
by them. Thus Robbins and Meyers grew and
prospered and insured that their line of
specialty motors had built in customers.
Carpet Cleaning
It was about this time that
a new application was appearing on the
horizon. Floor coverings were
changing. In the past the floors were
mostly hardwood and the soft coverings were small
to large rugs. When the rugs needed
cleaning they were picked up by a cleaner and
hauled to a location where they would be scrubbed
and vacuumed and then hung and stretched to
dry. Many of these rug-cleaning companies
also cleaned and refurbished upholstered
furniture. In some of the more wealthy
neighborhoods there was something new being put
down on the floor, something called wall-to-wall
carpeting. In Southern California, there
was a concentration of these homes in the areas
serving Hollywood. In 1947, a company
called Truman Doyle, who had a large rug and
upholstery cleaning business, saw a new
application coming, that of cleaning
carpeting. They envisioned a company with a
fleet of trucks that would travel and clean
carpets on site. They came to Sutorbilt
looking for a blower to build into a lightweight
portable cleaner. The finished product was
something called a “V2" rocket, named
after a missile of World War II, and which was
enclosed in surplus airplane parts, giving it a
somewhat futuristic look. The unit directed
the flow of air entrained liquid into an area
covered by a clear plexi-glass enclosure and
their motto was “See the dirt boil
out.” They built a number of these
units but did not take it outside of their own
company’s use.
By 1963 the business had
grown to where the “office in a
bedroom” would no longer suffice and an
industrial location was found in Santa Fe Springs
Packaging of
Blowers
Fabrication of packages was
now a larger part of the business. The
company had sort of backed into the business by
the policies of Sutorbilt. They had gone on
a standardization binge which included the
packaging of blowers. There were some 35-40
sizes of small blowers using motors up to 50
HP. In their efforts to reduce the number
of assembly sizes it was decided to build only
three size bases. One such unit was sold to a
local customer. When it was delivered, he
called and asked that someone come out.
Pointing to a base that took up a large area and
on which was mounted a small 2L and a 1 HP motor,
he wanted to know who was going to pay his rent
on the excess area covered by the large
base. In an effort to mollify the customer
it was decided to return the unit to Pacific
Pneumatics and repackage it into a more space
saving arrangement. Thus a business began
that was to become a major part of their
operation. Once again, Holzinger Bros.
Sheet Metal came to the rescue and did the
repackaging. As time went on, the packaging
was done in-house as Pacific Pneumatics grew into
a full packaging and fabricating facility.
Sutorbilt blowers formed the heart
of Pacific Pneumatics for most of its early
life. As the fabrication of what was to be
called “Engineered Products” increased,
more blowers were bought outright rather than
sold directly to the user with the billing by the
factory. As the OEM business for carpet cleaner
blowers increased there was a move to have
sufficient stock for their needs. Thus it
was deemed proper to have Sutorbilt supply
Pacific Pneumatics with consigned stock.
While this was going on Pacific Pneumatics moved
locations twice, both within a few hundred yards
of the first location on Marquardt in Santa Fe
Springs. To hold the stock of blowers,
large welded steel racks were built and the
offices expanded to hold the growing force of
office and sales persons.
The Powder Pump
In the early sixties, work
was done with Great Lakes Carbon Company and
Gorman Rupp Company to develop a better method of
conveying diatomaceous earth. Great Lakes
Carbon was one of the truly great privately owned
companies. Their method of doing business
not only extended to customer satisfaction, but
to the protection as well. If your bid to
them was low by any large percent, they would
call you and let you check your prices before
they gave you an order. Their headquarters
was in Chicago and they were owned by the Skakel
family. (One of the more prominent names
out of that family was Ethel Kennedy.) They
had diatomaceous earth plants at Walteria and
Lompoc in California and a perlite plant near
Soccoro, New Mexico. All these plants had
trouble handling these very abrasive but very
light weight
products.
It was found that a
diaphragm operated liquid pump could pump these
products if modified and if the product was
aerated. Gorman Rupp had the diaphragm
pumps; Pacific Pneumatics had the aeration
knowledge; Great Lakes Carbon had the product to
be conveyed. A number of designs were
tested and one was found to be
satisfactory. Now came a dilemma for the
other companies. Gorman Rupp was only
interested in building a product that had a
volume production possibility. This
application was interesting but not one that was
going to built in volume. Great Lakes
Carbon was not interested in the machinery
business. Thus it defaulted to Pacific
Pneumatics to build the package out of components
supplied in part by Gorman Rupp and to customers
mostly supplied by Great Lakes Carbon. (During
this time the Mining, Mineral and Pigments
Division was spun off and sold to General
Refractories and became known as Grefco and any
further references will be to Grefco.) The
Walteria plant at the bottom of the Palos Verde
Hills was closed as the earth was more valuable
as real estate than as a filter aid. I
believe the Real Estate people call it, location,
location, location.
As time went on the customer
relations engineer at Grefco (In the early days
was Howard Baker) would visit a customer and tell
them they needed a powder pump manufactured by
Pacific Pneumatics. The price was so and
so; call them with an order. We would ship the
unit; Howard Baker would trouble shoot the
installation and this product was a profitable
though somewhat limited in its sales.
(Somewhere along the line someone noticed the
“PP” connection of “Pacific
Pneumatics” and “Powder Pumps” and
this naming of products continued through
“Pore Poly” and “Posit Pulse”
Filters.
The Powder Pump was used in many
other applications but always had some
maintenance problems associated with the learning
of how it operated. Other companies offered
their air driven diaphragm pumps to the industry,
but with out any guarantees of performance.
Their price was so attractive that the customer
would buy, hoping that the pump could be used in
some liquid application if it didn’t pump
the powder. Thus Pacific Pneumatics was
limited to those customers who wanted an
engineered product. Over the years, the
units have been supplied in limited quantities
over the world.
In Summary
We will leave this
story of the positive displacement blowers in the
late 1970’s, as this is a story of some of
the early days of the positive displacement
blower industry as seen through the eyes of one
Mark Royston. Some of it is factual, a
large part fancy. It can be a testimony to
the fact that the Roystons have seen a lot of
positive displacement blowers sail down the river
of industrial progress and that some of this
knowledge is being transferred into this Web
Site. Don’t read it for fact, read it
for enjoyment.
By: Mark W. Royston
La Mirada, California
© 1999
Your feedback is welcome.
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