TECHNOLOGY
Mobile Labs Gather Refinery Data Delicate analytical instruments in field units give plant data with lab accuracy Competitive pressures are forcing oil refiners to learn more about their processes. Their approach: Instrument them, analyze them. And several companies have found that mobile laboratories are the best way to do this. Shell Oil, Phillips Petroleum, and Esso Research and Engineering have all taken this route. They settled on mobile labs to:
Esso Studies Instruments. Esso's mobile laboratory, housed in an aluminum truck body, was built by Perkin-Elmer to study unit operations and to evaluate various instruments for on-stream analyses. It features a Perkin-Elmer vapor fractometer, a unit that Esso has studied to show its use-
fulness in refinery applications. Esso plans to add a viscometer, a moisture analyzer, and a vapor pressure recorder for evaluation work. Phillips Petroleum carries its mobile lab in a semitrailer, uses it for process analysis, testing, and research. Phillips engineers want analytical data that define a process. Reason: computer control. Other Phillips' plans: analyze process dynamics; evaluate analytical instruments, automatic control systems, and data gathering equipment. Mobile labs have expanded the scope of instruments that can be used in the field, make it possible to get full scale operating data with laboratory accuracy, these companies have found. Results: improved products, more efficient processes, and a better understanding of basic refinery operations.
• Reduce cost of moving equipment from plant to plant. • Prevent damage to sensitive instruments. • Provide a conditioned environment in which the instruments can operate to best advantage. The typical portable lab—about the size of an average house trailer—is air conditioned and can hook up to the water, gas, electricity, and air lines in the refinery. Inside, they differ widely, depending on the purposes for which the unit is used. Often the equipment varies from job to job. Shell. Shell's trailer carries a gamma ray spectrometer to measure concentration of radioactive tracers, follow flow patterns through cracking units. Shell has also studied the densities of catalyst-vapor mixtures in an operating unit by measuring the attenuation of gamma rays from a cobalt-60 source. The trailer also contains equipment for routine analyses, a gas-liquid chromatograph, telephone cables, auxiliary power supplies, lab bench, cabinet for glassware, and a hoist for handling heavy test equipment. The engineering research group can install other instruments as needed to attack problems in distillation, extraction, and reforming. And, because the lab is mobile, the group can use it at any of Shell's refineries in the U.S. and Canada. 58
C&EN
FEB. 22, 1960
High Speed Camera Magnifies Time By 100,000 Scientists and engineers studying arc discharges, explosive reactions, and other high speed events can now "freeze" motion with the aid of a new movie camera that stretches the events of one second into 28 hours. Developed by Dr. Albert T. Ellis, an associate professor of applied mechanics at Cal Tech, it is being made commercially by Benson-Lehner Corp., Santa Monica, Calif. The movie camera can take from 480 to 1,600,000 pictures per second on standard 35 mm. black and white or color film, the company says. The camera has a disk-shaped film box with the feed and take-up magazines placed at the top. At the front end of the disk's center axis are the objective and shutter assemblies; at the rear, a high speed air turbine and a revolving mirror. An electro-optical shutter controls passage of light by rapid electric pulses. The film remains stationary while the mirror, rotating at 100,000 r.p.m., conveys the image from frame to frame. In the sequence above, the camera records what happens when a 30 caliber bullet is fired at 6500 ft. per sec. into a solid plastic plate. Note the fluid flow of solid under the high speed impact.
Electronics Aids Process Startup New controller circuits bring processes to steady state faster Minneapolis-Honeywell Regulator has designed some new controller circuits which reduce overshoot during instrument-controlled startup of batch processes. Result: Some processes which have demanded manual control during startup can now be turned over to the instruments, the company says. Objective during startup is to lock onto process conditions as fast as you can without overshooting the setpoint, Minneapolis-Honeywell engineer Robert L. Farrenkopf told the Instrument Society of America's winter meeting in Houston. But too often, he says, the instruments which can run the process once it reaches operating conditions cant handle the startup job. The usual problem, Mr. Farrenkopf says, is that the valve or other primary control element starts out wide open, shuts off or is throttled too late, so the temperature (or other process variable) coasts right past the setpoint. The M-H circuitry overcomes this by dividing the input signal to increase the reset time constant, begin the throttling process sooner. Exact circuit design depends on the process dynamics and control system elements. Major factors are process dead time and steady-state valve position (full open, half open, or the like), according to Mr. Farrenkopf. For low dead times, he says, you can use a two-mode circuit, get less than 3% overshoot. Three-mode circuits, however, give the engineers more leeway in steady-state valve positions, also reduce the time it takes to damp out oscillations around the setpoint (line out the process).
be the only way to form complicated tungsten shapes* the bureau says. The bureau's W. E. Reid and Dr. A. Brenner developed the process. First, they heat the object to be plated to about 650° C. in a hydrogen atmosphere. Next, they pass a mixture of hydrogen and tungsten hexafluoride over the hot surface. When it contacts the surface, tungsten is deposited. By-product hydrogen fluoride leaves the reaction area with the excess hydrogen, is absorbed in a trap. For best results, the surface should be at 650° to 700° C , the bureau says, but the process works from 300° to nearly 900° C. And for complex shapes, you may need a system of injector tubes to distribute the gases around the object, NBS points out. The tungsten coating is hard, less porous than coatings made by other methods, and more pure than the commercial metal. Silicon is the only metal present at 0.1% or more. Adhesion to nickel, molybdenum, and ceramics is good; to copper, somewhat weaker; to iron, poor. The tungstengraphite bond is as strong as the graphite itself. Tungsten is one of the few metals that show structural strength above 2000° C , NBS points out. Its high melting point (3140° C ) , hardness, and corrosion resistance are important to rocket, missile, and jet engine makers. But the metal can't be machined by ordinary methods. The vapor deposition method is the answer, the bureau feels.
TRIAL RUN. NBS vapor deposition process plates tungsten on a heated object in the ceramic cylinder (left). Here, W. E. Reid starts a run
The NBS process is similar to one worked out independently by the Bureau of Mines (C&EN, Oct. 5, 1959, page 24), except BuMines heats the gases rather than the surface. Alloyd Research also has a process that deposits metals from a mixture of hydrogen and a volatile salt (C&EN, May 25, 1959, page 50), but details are under wraps. Alloyd does say, however, that its process conditions are critical, while NBS says that wide variations in flow rates and pressure in their system have no major effect on process efficiency or coating quality. Alloyd has used its process to coat graphite rocket nozzles.
NBS Plates tungsten Vapor deposition process gives hard, smooth surface coatings National Bureau of Standards has worked out a fast, simple tungsten plating process based on vapor deposition. The method will coat simple or complex surfaces, may also be used to make tungsten articles. And this may
Sea Water Conversion Plant Starts Up Southern California Edison has started up an experimental sea water conversion plant at its power station near Oxnard, Calif. The unit uses nearly-spent steam that has already passed through the station's turbines, makes 100,000 gallons of potable water per day. Heart of the unit is a 26-stage flash evaporator more than 70 ft. long (shown here). The experimental plant, engineered by Cleaver-Brooks Special Products, Waukesha, Wis., cost more than $250,000, will provide technical and cost data for the design of large-scale water conversion plants. FEB.
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C&EN
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BRIEFS American Viscose is using four-storyhigh towers to dry and condition coated cellophane at its Marcus Hook, Pa., plant. After the coating step, solvent is drawn off on the upward trip through the tower, conditioning (return of water lost during drying) takes place on the downward leg. Reason for the vertical arrangement: Floor space at the Marcus Hook plant is at a premium.
Background is Furafil, photographed from 3 feet.
Furafil is a dark brown, modified cellulosic flour having a bulk density of 30-35 pounds per cubic foot. Furafil absorbs water readily, but does not swell appreciably in doing so. It is used widely where powdered, absorptive, organic solids are useful. Industries in which Furafil is used include the following: FOUNDRY
Furafil is used as a modifying agent for foundry sands to control expansion properties, and to compensate for thermal shock· This reduces the percentage of defective castings. FERTILIZER
Fertilizer manufacturers use 100 pounds of Furafil per ton of mixed goods to help prevent caking and preserve good drillability in the finished product.
Electropolishing can make strong, tapered tow lines, Southern Research Institute concludes from its research on stainless steel wire. Purpose of the tapering: to provide a cross-section which increases as strength needs increase along the length of a line, thus make longer lines which weigh less. Most interested party: the Air Force, which already uses lines more than 25,000 ft. long, sees a need for tow lengths up to 40,000 ft.
INSECTICIDES AND FUNGICIDES
An improved filtration system to purify
Furafil's high absorption characteristics make it a fine carrier for liquid ingredients and its anti-caking properties are also of value.
reactor cooling water has been devised by scientists at General Electric's Hanford, Wash., laboratories. The new system will save more than $200,000 a year. The group changed the proportions of sand, gravel, and anthrafilt (a sized anthracite coal) and has added a filter-conditioning chemical to settled water as it enters the filter. Results: Fewer chemicals are used; the filter need not be precoated.
PLYWOOD
A special, finely ground grade of Furafil is used as an extender for phenolic resin glues employed in the manufacture of Douglas fir plywood. Furafil is available throughout the year. Write for a sample so you can evaluate it in your process.
The Quaker Qats Company CHEMICALS DIVISION 333R The Merchandise Mart, Chicago 54, Illinois Room 533R, 120 Wall Street, New York 5, New York Room-433R, 48 S.E. Hawthorne Blvd., Portland 14, Oregon Room 6153R, 815 Superior Ave., Cleveland 14, Ohio
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Aluminizing process for high temperature service has been developed by Wall Colmonoy, Detroit, Mich. The sprayed aluminum coating is bonded to the base metal at high temperature in a controlled atmosphere, can be used on series 400 stainless steels, carbon steels, and many alloys. The company claims the coating is more uniform, harder, and corrosion resistant.
C&EN
FEB. 2 2, 1960
More efficient power generation is the goal of a new generating cycle to be installed by General Electric for Ohio Power at Beverly, Ohio. The system will combine a 5000 kw. coal gasdriven turbine with a 215,000 kw. steam turbine to cut the amount of coal used to feed the steam turbine as well as to improve over-all efficiency by an expected 4%.
