Steam Jet Ejectors
From Vacuum Products
Steam Jet Ejectors — the largest vacuum producing devices available — are used in the most demanding of applications. Virtually maintenance-free with no moving parts, they can be fabricated from almost any material, and can be used in every industry that requires vacuum. Ejectors can be designed to operate without steam as their pressurized (motive) source. In addition to operating well into the micron HgA range, they can also operate well above atmospheric pressure.
Graham has mastered Steam Ejector design. Featuring proven, unique internal geometries and tightly tolerance-controlled steam nozzle configurations, Graham ejectors produce very low steam consumption and highly efficient operation. As an experienced provider of Engineering Answers since 1936, Graham maintains the most comprehensive database of actual steam ejector performance information available today.
Combine Graham Steam Jet Ejectors with other Graham equipment, such as Process Condensers and Liquid Ring Pumps, and you have a single source of supply and a responsible, total solution for process equipment needs.
Graham Corporation brings more than 70 years of proven experience to the application, design, and operation of ejector systems. Our experience spans a wide range of applications and markets, including systems for space simulation, high vacuum applications in metals vacuum degassing, applications involving vapor-liquid and chemical equilibrium for fertilizer plants, sophisticated process simulation applications for crude vacuum distillation, and a host of other specialized and unique services.
Graham's experience combined with the company's continuous research and development efforts in ejector efficiency translate into real advantages for customers.
Advantages of Graham Steam Jet Ejectors
- Proven Experience
- Single Source of Supply
- Comprehensive Product Testing
- Ongoing Research and Development
- Operating Efficiency Enhancements
- Global Technical Support
Graham Steam Jet Ejectors are being used in many applications world-wide. Some of these applications include:
- Crude oil distillation
- Petrochemical processes
- Edible oil deodorization
- Organic motivated systems
- Fertilizer plant operations
- Thermal compressors
- Hybrid vacuum systems
- Metals vacuum degassing
- Space simulation
Crude oil distillation
Motor gas and lube oil refineries have a number of applications for ejector systems. Crude vacuum distillation, lube oil distillation, vacuum flasher, and gas oil hydrodesulphurization are the typical applications. Graham ejector systems support the majority of refinery vacuum distillation applications throughout the world. We have computer simulation programs that accurately model vacuum tower overhead hydrocarbons and we have specialized condenser designs for handling mixtures of miscible hydrocarbons and steam in the presence of large volumes of non-condensable gases.
Our vacuum condenser design supports the ejector systems by providing accurate simulation of vapor/liquid equilibrium, optimal condensation efficiency, and minimal pressure loss across the condenser.
Petrochemical processes are vacuum intensive and there are requirements for single, two, three, and four stage ejector systems. Common processes include cumene, phenol, ethylene glycol/ethylene oxide, ethylbenzine/styrene monomer, amines, alcohols, and caprolactam, to name a few. Graham has a wealth of knowledge in the design, application, and integration of ejector systems into petrochemical applications.
Edible oil deodorization
Edible oil plants use Graham ejector systems for deodorization. These are four-stage ejector systems, operating in the range of 1 to 3 torr. Reliable operation is critical to provide proper deodorization of the oils. Other ejector applications in edible oil refineries include vacuum bleaching, hydrogenation, deaeration, and interesterification. Graham also provides ECOfreeze vacuum systems for edible oil deodorization.
Organic motivated systems
Use of alternative motive fluids may offer an advantage in specific applications. Graham has proven installations using ethylene glycol, monochlorobenzene, cyclohexane, methanol, phenol, and refrigerants as the motive fluid. Customers consider ejector systems using motive fluids other than steam under any of the following conditions:
- When there is a need to recover product for use or disposal without water contamination and associated expense of removal
- When solids are present or process vapors deposit in ejectors, but dissolve in an organic fluid
- When backstreaming of steam into the process cannot be tolerated
- When the presence of water may introduce a serious corrosion problem
- When contaminant scrubbing is easier in the absence of water
- When there is a desire to reduce or eliminate air and water volatile organic compound contamination
The main advantages of using an organic fluid for an ejector are the motive fluid acts as a solvent for the process vapors, the process is not contaminated with steam/water, chemical treatment problems are minimized, and the total energy requirements are considerably less than if steam were used as the motivating fluid. An organic motivated ejector system most often is a packaged, self-contained system that includes ejectors, condensers, a vaporizer, coolers, pumps, controls, piping, all auxiliaries, and packaging.
Fertilizer plant operations
Urea plant vacuum systems are specialized in that the design must incorporate features in the vacuum condensers due to exothermic heat reaction liberated by chemical reactions that occur. The design requires a combination of vapor-liquid and chemical equilibrium. It also is necessary to minimize the amount of ammonia gas exiting the vacuum system.
Graham has installed a number of urea plant vacuum systems throughout the world that are providing excellent performance, in many cases, they are running at capacities in excess of 100% without sacrificing vacuum in the concentration vessels. Graham also has provided a number of high pressure carbamate liquid eductors where high pressure carbamate solution is boosted in pressure with liquid ammonia for return back to the reactor.
Thermal compressors (or Thermocompressors) boost an intermediate steam load to a higher pressure with high-pressure motive steam. A common application is in vacuum concentration or evaporator service. Efficient thermal compression operation is vital for economic operation of the evaporation plant. Graham continues to develop improved thermal compressor designs to reduce energy consumption.
Hybrid vacuum systems
When the application calls for reducing motive steam usage by combining ejector and liquid ring vacuum pump technology, Graham manufactures both. A hybrid vacuum system will have ejectors for the primary (high vacuum) stages and a liquid ring vacuum pump will replace the last ejector stages. This provides an advantage of reducing motive steam consumption by replacing the last ejector stages with a liquid ring pump.
Metals vacuum degassing
Micron range ejector systems are required for metals vacuum degassing applications. Graham has supplied a number of installations where ultimate suction pressure is 10-30 microns.
High altitude or space simulation requires large multi-stage ejector systems. Graham has supplied a number of government agencies with these specialized vacuum systems.