The 2003 Panel of Judges
Achieving and maintaining peak operating efficiency remains a top priority throughout the chemical industry. Suppliers can play a key role in making that quest easier.
So, every other year since 1964, Chemical Processing has bestowed the Vaaler Awards to recognize vendor developments that promise to significantly enhance plant operations or economics. This year, we honor seven innovations. Details about them appear on the following pages.
The awards are named for John C. Vaaler, Chemical Processing's editor-in-chief from 1946 to 1961, and chairman of the magazine's Editorial Board until his death in 1963.
To be eligible for the award, the product or service must have been commercialized in the United States between March 2001 and April 2003. An independent panel of judges evaluates all entries for technological significance, novelty or uniqueness, and breadth of application. This year, the judges assessed more than 60 developments.
Portable Unit Safeguards Powder Transfer From Drums
The DCS provides an exceptionally low operator exposure level (OEL) of
<1 g/m3 @ 1 m, thus reducing the need for personal protective equipment. It is a compact, portable unit, while the alternatives for achieving that OEL -- glove-box isolators or a clean room -- are substantially larger and more expensive.
The unit includes several containment barriers. A glove box ensures a dust-tight seal with the drum and has integral filters for venting. It operates under a slight negative pressure, preventing exposure should a barrier fail. Both inner and outer drum liners are attached to a sealing ring. And a containment sleeve isolates the suction lance. Even cleaning and filter changing take place in total containment.
The DCS uses several containment barriers to achieve exceedingly low operator exposure levels to hazardous materials in drums.
The DCS can be added to existing processes without the need to modify the production equipment or building. It is suitable for services that must comply with U.S. FDA regulations. Its reliable all-pneumatic design makes the unit appropriate for explosion-proof areas.
The system can handle virtually any diameter drum and kind of liner. The height of the glove-box assembly can be adjusted to accommodate different size drums. The unit can be moved from one area to another by a forklift or pallet truck. The counterbalance support for the suction lance retracts to reduce the height of the unit during transit.
The unit requires only one operator. The suction lance is manipulated easily from outside the glove box to allow maximum operator freedom of movement. The wand has a guard to prevent the liners from blocking the wand opening and a counterbalance to reduce operator fatigue.
The DCS complements the company's PTS (powder transfer system), which is attached to process equipment like reactors and other vessels, for charging material.
De Dietrich Process Systems, Union, N.J.
Application Makes Implementing Model Predictive Control Easy
DeltaV Predict can replace PID controllers for a single-input/single-output process or multivariable controllers for an entire unit such as a distillation column or even a whole process area. It can handle complex control problems not suitable for single-loop controllers and effectively address problems such as dead-time dominance, multiple constraints and multiple disturbances.
The MPC functionality is embedded right in the DeltaV process control system. This drastically reduces cost and complexity -- but not the power of the technique -- and makes it economically viable for many more applications.
Embedding eliminates the need for a host computer and the work of building communications to that computer. And it means that the algorithms run in a high-speed rugged environment that can provide redundancy.
DeltaV Predict uses the same engineering environment as DeltaV and automatically builds the operator interface. Custom operator displays are created with a single mouse click.
DeltaV Predict makes model predictive control easier to implement.
Its MPC function blocks allow multivariable model-based control strategies to be implemented much more easily than with traditional PID-based tools. The function blocks come in two sizes. The smaller one suits process control applications with as few as one input and one output, or as many as three inputs and three outputs with a maximum of two controlled and two manipulated variables. The larger function block supports as many as eight inputs and eight outputs and four controlled and four manipulated variables.
DeltaV Predict fully automates testing during the model-development process and then automatically generates the MPC controller. Controller generation is speedy. For fast-responding processes, it might take only a matter of seconds -- in contrast to the hours or days needed for traditional multivariable-control techniques.
DeltaV Predict has replaced single-loop controllers that performed poorly because of dead-time dominance. It also has been used to control entire distillation columns.
Model predictive control is implemented as a function block.
Noel Perez, Technical Services Manager at Baxter Healthcare's facility in Guayama, Puerto Rico, notes, "By using MPC ... we managed to reduce the cycle time of the carbine distillation by 20 percent. That resulted in a 5.4 percent capacity increase of the plant, which means for us almost $2 million in manufacturing variances." "The robustness of the control exceeds all expectations ... To date, we are achieving near-100-percent control program uptime," says Dave Sordi, process control engineer at Canadian Forest Product's Northwood Pulp Mill in Prince George, British Columbia.