DIAL has been a research department in the College of Engineering at Mississippi State University since 1980. Approximately 50 professional and support personnel are associated with DIAL. A number of the professionals hold joint appointments in academic departments in the College of Engineering and the College of Arts and Sciences.

Under the leadership of DIAL's recently retired director, W. Steve Shepard, funding was secured from DOE and the state of Mississippi for a new 58,000-square-foot facility, which will more than double DIAL's research space. Construction began on this state-of-the-art facility in early 1996, and the projected completion date is late fall of 1997. The new DIAL building will be in the Mississippi Research Park adjacent to the MSU campus.

John Plodinec, who became director of DIAL in April, sees DIAL becoming the solutions provider of choice for process problems in harsh environments. "Because of its unique combination of ingredients, DIAL can provide proven solutions to processing problems in a rapid and cost-effective manner. DIAL is virtually alone in combining a highly qualified research staff (with expertise in process monitoring and control) with a highly capable engineering staff (experienced in conducting tests in harsh environments). This means that if a solution to a problem already exists, the customer doesn't need to invest in developing something new--DIAL will simply transfer the technology. But if technical development is needed, the research staff will bring to bear their expertise to point the way toward a solution, and the engineering staff will prove that the proposed solution actually works. Our experience with high-temperature equipment, particularly plasma and off-gas systems, gives us confidence in our ability to carry out testing even in the harshest of environments."

Taking the pulse of a plasma torch electrode

DIAL has developed a monitor to indicate when eroding electrodes in a plasma torch threaten a vitrification system. A plasma torch is an electric-arc furnace that subjects contaminated material to temperatures ranging up to 15,000 degrees Fahrenheit--hotter than the surface of the sun. The continuous operation of a plasma torch wears and erodes electrodes, the parts in a plasma-torch vitrification system that create the electric spark to ignite the plasma gas.

As an electrode wears, its material is vaporized and introduced into the torch gas flow. This material is excited and emits a particular spectral signature when it exits the torch nozzle. This signature provides specific information on the erosion occurring within the electrode. DIAL developed torch electrodes that are doped at a given depth with an indicator material. When the electrode erodes through to this material, the emission spectras from the arc signal the need to schedule the replacement of the torch electrode.

Extending electrode life

DIAL's research has tripled the operating life of the Retech model RT 75-T plasma torch electrodes. Electrodes are designed as hollow cylinders, closed at one end and open at the other. The electric arc from the electrode attaches to the inside surface of this hollow cylinder and exits through the open end. The outside of the cylinder is cooled with a continuous flow of water to remove the heat being transferred to the electrode by the arc. The plasma gas required to operate the torch is injected into the gap between the electrode and the nozzle.

By varying the rate of plasma gas flow between the electrode and nozzle, DIAL moved the location of the arc attachment point on the electrode. This strategy distributed electrode wear along the inside surface of the electrode, preventing wear in any one spot from shutting down the system. Other areas of research to extend electrode life include using various alloys for electrode material and improving electrode heat transfer to the cooling water.

Testing and adapting commercial technologies

Director Plodinec also believes DIAL has a role to play in speeding the deployment of new technologies. "It is a sad fact of modern life that obtaining regulatory acceptance often is an almost insurmountable hurdle for an inventor to overcome. In the future, we hope that DIAL can act as a catalyst to speed the regulatory acceptance process. We would like to see DIAL become a sort of 'Universal Testing Laboratory' for new technologies, benefiting users, regulators, and inventors. The users will have greater confidence in new technologies, because DIAL--a disinterested party--will have tested the technologies and certified their suitability. The inventors would gain regulatory acceptance more rapidly, thus helping them get to market sooner. The regulators would achieve thorough and consistent testing of new technologies and thus make more rapid and more accurate regulatory decisions."

DIAL's Field Application, Coordination, Testing, and Support Program locates promising technology in the private sector and evaluates its application to DOE problems. During shakedown testing of the Transportable Vitrification System (see Initiatives, December 1996) in February 1996, DIAL evaluated MDA Scientific's Single Point Monitor, a chlorine analyzer that is based on MDA's proprietary Chemcassette Detection System.

A gas sample was passed over a small cassette of paper tape specially formulated to react with specific gases. A small dot of color on the tape indicated a chemical reaction between the gas and the tape. Traditional colorimetric techniques measure the intensity of the colored dot, which is proportional to the concentration of gas in the sample. DIAL's analysis of the monitor helped the manufacturer correct minor problems.

DIAL combined two known technologies to develop a continuous emission monitor to measure the concentration of RCRA metals (those included in the Resource Conservation and Recovery Act) in the off-gases of thermal treatment systems. DIAL combined the capabilities of Laser-Induced Breakdown Spectroscopy with Laser Optogalvanic Spectroscopy. LIBS monitors the concentration of many metal species simultaneously, while LOGS offers greater detection sensitivity but can monitor only one species at a time. DIAL's hybrid LIBS/LOGS system uses LIBS to simultaneously monitor beryllium, cadmium, chromium, and lead, while LOGS sequentially monitors concentrations of arsenic, mercury, and antimony. The concentration of all seven RCRA species can be measured in under four minutes and their concentrations electronically transmitted to the facility.

For more information about Mississippi State University's DIAL, see its Web site at http://www.msstate.edu/dept/dial, or contact John Plodinec, director, Diagnostic Instrumentation and Analysis Laboratory, P.O. Drawer MM, Mississippi State, MS 39762-5932, phone (601) 325-2105, fax (601) 325-8465, e-mail dial@dial.msstate.edu.