Seven Innovations Earn Honors

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
Hazardous powders such as explosive and carcinogenic or skin-sensitive materials often are handled in drum quantities to minimize risk. Drums also are used to hold oxygen-sensitive products and many other powders. Unfortunately, emptying these drums can pose risks of worker exposure and material contamination. The DCS (drum containment system) enhances the safety of such transfers, while reducing their cost compared to alternative methods. It allows the transfer of materials in an inert environment and can be used in a production area without endangering nearby personnel or disrupting other manufacturing processes.

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 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.

Application Makes Implementing Model Predictive Control Easy
The value of constrained multivariable model predictive control (MPC), which forecasts the future behavior of a process by developing an accurate model, is well established. It can address process interactions and difficult dynamics effectively, and enable optimum economic operation of an entire plant, not just a few loops. The problem for many would-be users is that implementation has been difficult and expensive. So, only large and complex plants could justify MPC. DeltaV Predict changes the ground rules. It, as one judge comments, "makes benefits of MPC feasible to implement on many process units, rather than just complex, very economically sensitive ones." "It allows even less-experienced engineers to solve difficult problems," says another judge.

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.