Seven Innovations Earn Chemical Processing Honors

Many plants stand to benefit from these recently commercialized developments

By Mark Rosenzweig, Editor-in-Chief

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The Winners

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.

DeltaV Predict is designed to provide good control performance even when the process gain and dynamics change with throughput and operating conditions. So, periodic recommissioning of the controller might not be necessary.

Emerson Process Management, Austin, Texas

 

More-Benign Heat-Transfer Fluids Replace Biphenyls

One judge describes them as "environmentally friendly and effective at the same time."

Xceltherm LV fluids, which consist of mixtures of diphenyl oxide and
1,1-diphenylethane, do not face any regulatory reporting requirements, yet offer physical and thermal properties almost identical to diphenyl-oxide/biphenyl mixtures. The LV fluids can serve as drop-in replacements, including for makeup in existing diphenyl-oxide/biphenyl systems. Plants that have switched over entirely have needed minimal, if any, system adjustments or modifications.

Rick Jones, operations supervisor at the Pinova Div. of Hercules in Brunswick, Ga., was drawn to Xceltherm LV because of its environmental friendliness. He switched three boilers from biphenyl-containing fluid in May. Radco took the old fluid and cleaning solution and provided a credit for usable materials recovered.

The boilers are operating extremely well. "It's an excellent fluid. We haven't seen any performance problems," notes Jones. The boilers even run at a little lower pressure, he added. Jones now is planning to convert other boilers on the site. Avoiding costs incurred by biphenyl-containing fluids is a factor, but the more-benign nature of Xceltherm LV is his prime motivation. "It's great to know that you're not causing environmental damage," he emphasizes.

The fluids also offer benefits over non-biphenyl liquid-phase alternatives being used in the temperature range of 600 Degrees F to 660 Degrees F. Xceltherm LV can provide a 15 percent to 25 percent boost in heat-transfer efficiency, which can translate into energy savings in existing systems or smaller components in new units. The fluids also boast better thermal stability, leading to longer life.

The three fluids in the series, LV1, LV2 and LV3, are designed to offer improved crystallization points -- 45 Degrees F, 11 Degrees F and -35 Degrees F, respectively -- and low-end operating ranges compared to diphenyl-oxide/biphenyl mixtures. The lower crystallization points may eliminate the need for heat-tracing. The fluids can be used in the liquid phase from -35 Degrees F to 700 Degrees F and the vapor phase from 496 Degrees F to 700 Degrees F.

Radco Industries, La Fox, Ill.

Xceltherm LV1 provides a higher heat-transfer coefficient than biphenyl blends at temperatures above 650 Degrees F.

 

Hybrid Design Provides Better Wet Milling

 

MKO 2000 Cone Mill combines a stone mill's grinding action with a colloid mill's fluid-dispersing capabilities.


The Cone Mill achieves this performance because of the unique hybrid design of its milling tool. This combines the grinding action of a stone mill with the fluid-dispersing capabilities of a colloid mill. The tool produces an intense shear zone that can process materials with high or low viscosities.

"A nice, two-in-one machine," one judge concludes.

The mill features a conical-shaped rotor and stator arrangement that provides extremely fine milling action. The rotor has an initial stage of spiral-shaped teeth and then two stages of progressively finer rough coatings to abrade material. The stator also has abrasive coatings in increasing fineness. The coatings consist of very hard materials such as carbides and ceramics. The gap between the rotor and stator determines the amount of milling action and is adjustable so that the desired amount of milling can be achieved. The nominal tip speed is 4,500 fpm.

The MKO 2000 comes in six standard models, with maximum flow rates ranging from 10 lb/hr to 6,000 lb/hr. Actual flow rate depends upon the gap setting and material being processed. It can be reduced to as low as 10 percent of the maximum rating for difficult-to-process materials and near-zero gap settings.

IKA Works, Wilmington, N.C. 


Nonwoven Media Boost Baghouse Performance

The media are made via a proprietary web-forming and hydroentangling process combined with sophisticated finishing. This provides superior uniformity, tightly controlled pore-size distribution and, thus, high filtration efficiency and low pressure drop. Durapex PM2.5 boasts greater fabric strength than needlefelt at a lower weight basis. The media also avoid the inherent disadvantages of needlefelt -- needle penetrations that can cause mechanical damage and leave large pores.

Durapex PM2.5 media come in a variety of materials including polyester, Ryton polyphenylene sulfide for corrosive services to 375 Degrees F, and Nomex aramid for temperatures up to 400 Degrees F, in both non-screen-supported and screen-supported versions.

Polymer Group Inc., Mooresville, N.C.

 

Durapex PM2.5 boasts smaller, more uniform pores than standard needlefelt. 


Skimmer Minimizes Water Pickup

The Gyroskimmer is compact, lightweight and easy to set up, even in underground tanks. The smallest model, the 602GY(P), weighs less than 29 lb., while the largest, the 1200GY(P), is only 60 lb. The skimmer features a built-in submersible pump and does not require any other equipment for operation. An optional motor-driven scraper vane can be added to prevent blockage by sludge or scum if that is a concern.

Each unit consists of sets of outer and inner floats, a suction gate ring, and a hopper for collection of the waste. The two sets of floats work independently. Three large outer floats support the unit, including the hopper and hoses, while three inner floats maintain the suction gate at water level regardless of waves, preventing suction drag.

The shape of the floats keeps them from interfering with intake and the curved surface of the suction gate impedes air from entering. The suction gate is vertically adjustable, to a depth of 0.28 in. to 0.39 in., depending upon model, to accommodate surface layers of different thickness.

Made of stainless steel and polypropylene, the Gyroskimmer resists corrosion and handles temperatures up to 104 Degrees F. The 602GY(P) model has a discharge diameter of 1 in., while 800GY(P) and 1000GY(P) have 1.5-in. diameters and the 1200GY(P) has a 2-in. diameter.

World Chemical USA, Torrance, Calif.

Gyroskimmer relies on novel twin float system. 


Internet-Based Approach Cuts Cost of Silicon-Based Products

Xiameter just offers common silicon-based materials and only in bulk quantities, which can be truckload, tankcar-load or pallet, depending upon product. Terms for credit and delivery are standardized. Shipping dates are guaranteed and are based on set product lead times of 7 days to 20 days, according to region.

The approach goes further than just standardization, however. Xiameter relies on a Web-based order-entry system coupled with supply chain management software to process orders, update and manage inventory levels, provide shipping confirmation and handle customer invoicing without human intervention. Customers can get pricing information and place and check the status of orders in real time on the Web site. Orders also can be telephoned in at a nominal surcharge.

 

Xiameter offers materials only in bulk quantities such as tankcar loads.

"Xiameter is a great example of using the manufacturer-customer interface at a new level of cost effectiveness," notes one judge. Switching to Xiameter certainly has paid off for one maker of sealants, says its operations manager. He reckoned that the firm has saved at least 20 percent on all products supplied by Xiameter, and its record for on-time delivery has been impressive. No wonder, he added, that his firm has honored Xiameter as "Supplier of the Year."

Xiameter currently offers more than 300 silicon-based fluids, sealants, silanes and resins. Xiameter/Dow Corning, Midland, Mich.

 

Some customers buy standard silicon-based materials in large quantities. They know exactly what products they want and how to use them. They don't want to pay for services and other extras they don't require. Xiameter is specifically aimed at these customers. It provides high-quality products at the lowest base prices available by taking advantage of existing Dow Corning technology and the efficiencies of the Internet. Conventional skimmers for removing sludge, scum and oil from wastewater tanks tend to collect a large amount of water as well, often necessitating further separation steps. The Gyroskimmer employs an ingenious design, as one judge characterized it, that relies on two sets of floats to minimize the pick up of water and ensure reliable and constant skimming. Four models provide capacities ranging from 4 gpm to 26.4 gpm and maximum heads from 13 ft. to 23 ft.Baghouses control particulate emissions in a diverse array of processes ranging from cement making to flour milling. And the importance of these filters is bound to increase as the U.S. EPA clamps down further on dust with its upcoming 2.5 m particle-emission regulation. So, operators of baghouses will welcome Durapex PM2.5. The nonwoven filtration media meet that upcoming rule and offer unmatched durability and, with it, cost savings vs. needlefelt and PTFE-laminated nonwovens.Materials that are extremely hard such as some pigments and crystals can be difficult to mill and may need multiple passes through traditional equipment like colloid mills. This can cause bottlenecks in production and lead to high maintenance costs. Hard seeds such as mustard may require soaking and heating before milling, adding to manufacturing time and cost. The MKO 2000 Cone Mill alleviates such problems. It also may eliminate the need for pre-milling of materials, and, thus, cut materials costs. Plus, the unit can produce smaller particle sizes than a colloid mill.Biphenyl-containing heat-transfer fluids remain widely popular because of their high heat-transfer efficiency and thermal stability at elevated operating temperatures. However, the fluids are subject to environmental regulations that mandate reporting and penalize companies for emissions and spills. The Xceltherm LV series of fluids doesn't pose such environmental issues and is compatible and performs comparably with biphenyl-containing ones. The fluids also boast lower removal and disposal costs.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.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.
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