EEE Prep - Business, Company, Products

Company snapshot

EEE designs, builds, tests, and services turbomachinery

What turbomachinery products?

centrifugal/axial compressors, steam turbines, turbine generator sets, power recovery expanders, cryogenic pumps and expanders

Company analogy

Company that moves and transforms the energy in gases and liquids for customers in refineries, chemical plants, LNG, and power

Fact: Age?

About 110 years

Fact: Test power?

As of 2025, allows testing up to 100 MW (134,000 hp)

Fact: Balancing capacity?

At-speed balancing for rotors up to 284 in long, 96 in diameter, 27,000lbs, 30,000 RPM

Fact: Quality credentials?

ISO 9001 service centers, ASME U and R stamps, welders per ASME Section 9

Fact: Parent Goal (Sustainability committment)

Carbon neutrality by 2050

What are the 3 business units?

New Apparatus, Global Manufacturing, Global Services

What is New Apparatus?

engineers and sells new machines (application, design, project engineering)

What is Global Manufacturing?

builds and tests machines (machining, welding, assembly, balancing, API testing)

What is Global Services?

keeps installed machines running, including from other brands (field service, repair shops, rerates, parts, training)

Overview of EEE in one complete sentence

Elliott is a 110 year old turbomachinery OEM that designs, builds, tests, and services compressors, steam turbines, and cryogenic pumps for the oil and gas, chemicals, LNG, and power industries, and is has now expanded to the hydrogen and carbon capture markets.

EEEs core product

Compressors - centrifugal and axial

Families of compressors?

Centrifugal and Axial

Compressor casing styles?

Horizontally split and barrel

How does a centrifugal compressor stage work?

It’s the same principle as the centrifugal pump I worked on at Cliffs, just with a compressible fluid. The impeller does work on the gas and flings it outward, so the gas leaves with high velocity and some added pressure. The diffuser widens the flow path, which slows the gas down, and that kinetic energy converts into pressure. Then the return channel guides it into the next impeller.

What are diaphragms in a compressor?

The stationary parts between impellers that guide the gas from one stage to the next

What is a single-stage overhung compressor?

One impeller is hung off the shaft end; they’ve been around for over 90 years and are used for dirty, corrosive, or hot service

What is the M-line?

Multistage, horizontally split, centrifugal compressors; up to 320,000 icfm and 400 psig

What is the MB-line?

Multistage barrel (vertically split) centrifugal compressors; up to 154,000 icfm, installations over 600 psig

Why use a barrel casing instead of horizontal?

A barrel casing holds much higher pressure because it doesn’t have the long bolted horizontal joint, which gets harder to seal as pressure rises. So for high-pressure service, like hydrogen in hydrotreating, the barrel is the right choice, especially since hydrogen leaks easily. The tradeoff is maintenance: with a horizontally split casing you can lift the top half off, so for high-flow, lower-pressure services that’s usually preferred.

Which service almost always uses vertically split (barrel) compressors?

Hydroprocessing (hydrotreating and hydrocracking) because of high hydrogen pressures

Name the 5 multistage configurations (compressors)

In-line, in-line with side streams, in-line with iso-cooling, double flow, back-to-back

What do side-streams do?

Let gas enter or leave between stages (common in refrigeration)

Why intercool between stages?

Cooling the gas cuts the compression work required, which saves energy (cooling a gas increases its density, if the pressure is the same, ex: hot air rises, cold air sinks)

Why use multiple stages (compressor)?

Each impeller can only add so much pressure, so stages are stacked on one shaft to reach higher pressure

Centrifugal vs Axial compressor?

A centrifugal compressor flings gas outward through an impeller and works across a wide range of pressures. An axial moves gas straight along the shaft through rows of rotating blades and stationary vanes, with a small pressure rise per stage, so it’s the choice for very high flow at moderate pressure. At Cliffs, the blast furnace blower was a 10-stage axial driven by a steam turbine, and you could see the adjustable stator vane linkages along the casing

Why do inlet guide vanes beat a throttle valve for flow control?

A throttle valve wastes energy by dropping pressure; guide vanes turn the gas into the impeller with less loss, so less power is used

What is compressor surge, and why do we care about it?

Surge happens when flow drops so low that the compressor can’t produce enough pressure to overcome what’s downstream, so flow reverses. Then the pressure downstream drops, forward flow resumes, and the cycle repeats. It’s violent: it reverses the thrust load, overheats the gas, and can damage seals, blades, and bearings. That’s why compressors have anti-surge valves that recycle gas to keep the flow above the surge line. I was at Cliffs when one of the turbo blowers tripped, and you could feel the surge through the floor.

You mentioned a pump project at Cliffs. What is cavitation, and how would you check whether a pump is at risk of it?

Cavitation is when the pressure at the impeller eye drops below the liquid’s vapor pressure, so vapor bubbles form and then collapse as pressure rises. The collapse pits the impeller, almost like sandblasting, and you’ll hear a gravel sound and see vibration and lost head. To check the risk, you compare NPSH available from the system, which depends on suction pressure, liquid level, friction losses, and vapor pressure, against the NPSH required from the pump curve, and keep a margin.

What’s the difference between a backpressure and a condensing steam turbine?

A condensing turbine exhausts into a condenser under vacuum, which maximizes the pressure drop and the power per pound of steam, but the exhaust heat is lost to cooling water. A backpressure turbine exhausts at a useful pressure into a header that feeds plant processes, so it makes less power but uses the leftover energy, which is why it’s common in combined heat and power. The choice depends on whether the plant needs process steam.

Why Ebara Elliott, and why the rotational program?

It really comes down to my internship at Cleveland-Cliffs. I was placed in Utilities, and the only steam and power systems I knew were from thermodynamics problems. My manager built on that and showed me how it all works in a real plant. I was fascinated by how interconnected the steam, compressed air, and condensate systems were, and I felt the responsibility of knowing that if our turbo blowers or boilers went down, the furnace lost its cold blast and the mill stopped making steel.

That’s when I realized I like understanding things at the system level: what feeds into a machine and what depends on it. I also loved working with my hands, observing inspections and documenting findings, and having to defend my reasoning on repair and design decisions.

The rotational program gives me all of that. I’d see how these machines are designed in New Apparatus, built and tested in Manufacturing, and kept running in Services.

And honestly, Elliott came from my manager. On my last days, he was helping us think about where to apply, and when I went back through my internship notes, I found that he’d written down Ebara Elliott, specifically your Chicago Service Center in Crown Point, near our plant. After a summer around steam turbines, a 10-stage axial blower, and a top gas recovery turbine, I want to work for the company that designs and services that equipment.