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'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
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
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:
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
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.
Space simulation
High altitude or space simulation requires large multi-stage ejector systems. Graham has supplied a number of government agencies with these specialized vacuum systems.
By producing a vacuum at the turbine discharge, condensers increase the overall cycle efficiency. Graham has more than 70 years of design and fabrication experience in the steam surface condenser field. Our knowledge allows for an expedient, accurate design and fabrication process. Using design methodologies and practices that have been honed over time, we work closely with our customers to evaluate options that best meet each project抯 objectives.
Graham Steam Surface Condensers range from small packaged units used in the HVAC industry to large cylindrical condensers used for mechanical drive applications in power plants, refineries, or chemical processing plants. Circular shells to approximately 12 feet in diameter can be supplied to suit a variety of requirements. Due to shipping restrictions and costs, larger applications are provided in modular rectangular designs where the tube bundles and dome sections are joined at the jobsite.
Because of our considerable experience in condenser manufacturing, our ability to work with exotic materials as well as turbines with different exhaust configurations (down, top, axial), Graham can closely work with customers to evaluate options that best meet the specific requirements of any project.
Advantages
Graham completes all phases of work from inquiry bid through detail design, fabrication, and preparation for shipment of Steam Surface Condensers at our one facility. This approach helps ensure the highest degree of quality and efficiency.
Graham offers fully-optioned steam surface condenser packages to meet job specific requirements. Packaging creates a high quality product that minimizes installation effort and meets project-specific requirements.
Our Steam Jet Ejector and Liquid Ring Vacuum Pump air removal packages can be supplied with the Steam Surface Condenser as a complete system. Graham also manufactures the Graham Viking Atmospheric Relief Valve that provides an automatically resetting over-pressure protection for the steam side of the Steam Surface Condenser and turbine.
Advantages of Graham Surface Condensers
Applications
Graham condensers have proven to be reliable and are chosen for applications throughout the world, a few of which are below:
Power
Graham can provide a steam surface condenser suitable for virtually any power generating application. We are completely familiar with the condensing requirements of the latest cogeneration and combined cycle power facilities and have supplied condensers for a wide variety of these plants. We have also supplied condensers for alternative energy applications, such as refuse derived fuel and geothermal.
Graham steam surface condensers for the power industry have been provided for turbines with down, top and axial exhaust configurations. Circular shells to approximately 12 feet in diameter can be supplied to suit a variety of utility requirements.
Due to shipping restrictions and costs, larger applications are provided in modular rectangular designs where the tube bundles and dome sections are joined at the jobsite. The Graham modular design utilizes a maximum of shop labor to minimize field assembly requirements. In addition, the Graham modular condenser design incorporates features that ensure accurate mating of modules, with a minimum of field effort, greatly reducing time and expense for field labor at the jobsite during final installation.
Chemical processing
Graham has provided steam surface condensers for ammonia, ethylene, methanol, and other processing facilities. The ability to work with exotic materials, along with vast experience with various chemical processes, provides Graham with a significant advantage in the industry. In addition, Graham retains a number of engineers on staff to provide assistance and expertise on various topics that arise in the field.
Refinery
Due to the vast experience that Graham has obtained in providing vacuum systems for refineries, a key advantage has been gained in the supply of steam surface condensers. Industry specific practices and intensive refinery specifications are familiar to Graham.
HVAC
Graham manufactures skid mounted packaged systems, including the condenser, air removal package, condensate pumps, controls, and instrumentation at our facility in Batavia, NY. This complete packaging creates a high quality product that minimizes installation effort for this highly competitive market. A central control panel and other project specific requirements can be supplied. A fully optioned package with job specific requirements is available in lieu of inflexible standard products.
Low oxygen condensate
The DO2?system has been developed by Graham to supply cold deaerated feedwater. Use of the system is normally applicable to plants with large amounts of cold makeup water and where it is beneficial to eliminate the installation and use of a pressure deaerator. The DO2?system consists of a specially designed condenser with segregated reheat hotwell, an enhanced venting system, and a makeup water vacuum deaerator.
The DO2?system is described in ASME paper 87-JPGC-PWR-9 "Case Study, Real Life Optimization of a 120 MW Combined Cycle Cogeneration Plant" by Richard B. Stanley of Bechtel Western Power Corporation and also described in a Graham article Condensate Oxygen Control in a Combined Cycle System Without a Conventional Deaerator.
Marine
Graham has provided steam surface condensers for main propulsion and turbine generator applications aboard naval and commercial vessels. The range of application varies from the design and fabrication of condensers used in the main propulsion systems of the largest of naval vessels to the supply of small condensers for use aboard commercial ships. Graham has the staff and facility to design and manufacture to the most demanding engineering-intensive military applications.
