Silterra Sdn Bhd, a semiconductor and computer chip manufacturer based in Kulim, Malaysia, is one of the latest semiconductor companies to use the rotor concentrators designed by the Zeol division of Munters Corp. in Amesbury, Mass., to treat processing exhaust for less than the cost of traditional oxidation.

The devices are designed to treat VOC-laden exhaust streams from a variety of manufacturing processes, including spray painting and coating, wood finishing, printing, and investment casting.

The key to the lower costs of the Zeol units is that they concentrate contaminants. First, the honeycomb-shaped rotors of the concentrators draw processed exhaust air into the units. Munters infuses these rotors with a synthetic zeolite that the company formulated to be hydrophobic, unlike naturally occurring zeolite, which is hydrophilic. Adsorbing water reduces the VOC-removing performance of natural zeolite. Munters' synthetic zeolite repels water while it adsorbs VOCs and is 94 percent effective.

As a result, the air exiting the other side of the rotor can be discharged into the atmosphere. A small portion of the cleaned air, about 5 to 10 percent of the original volume, is diverted to a small heat exchanger where it is heated to 360°F, and directed back through a small section of the rotor. As the rotor turns, it is exposed to the hot stream, which removes the VOCs from the zeolite.

The heated stream picks up and removes all the VOCs from the zeolite, concentrating them to make them easier to treat. The concentrated contaminant stream can be sent to a catalytic or thermal oxidizer, or to a solvent recovery system.

The essential oils in aromatherapy are liquids distilled or condensed from plants, herbs, trees, flowers, or seeds. Their aromas are inhaled in the belief that they can provide benefits, such as boosting the immune system or reducing stress. These scents are expelled in specific dosages through a diffuser by means of a motorized air pump.

Rena designed its RA 200 motorized air pump to deliver aromatherapy essences quietly.

Diffuser manufacturers in Europe approached Rena's sister company in Annecy, France, to design a reliable air pump to deliver dosages that would not interfere with the aromatherapy, for example, by contact with metal that could contaminate the oils. Just as important, the pump had to be silent.

Rena's engineers devised three innovations for their RA 200 aromatherapy pump to quiet its operation. They equipped the unit with expansion chambers to absorb vibrations at the valve-block outlets, while ensuring strong, regular flow rates. Second, they fashioned curves with a progressive radius to trap residual noises inside the casing, suppressing 99 percent of the vibrations. Last, they precision fitted the pump base to ensure that vibration and motor nose remain trapped inside the pump. As a result, the pump's noise level is less than 30 decibels.

A needle valve air control precisely regulates the airflow provided by the RA 200. Rena made the pump compact—5 1/2 inches long by 2 5/8 inches wide and 2 5/8 inches high—so it can be used with the small, portable diffusers favored by aromatherapy enthusiasts.

The RA 200 was recently incorporated into diffusers by Neways International, a Salem, Utah, personal care and cosmetics company and a leading aromatherapy concern. Neways sells its aromatherapy diffusers equipped with the Rena pumps in 11 different countries, including the United States.

The curved bill within Red Valve's Series 39F inline check valve enables it to seal around entrapped debris during flood controlling operations.

The 7-foot-diameter 39F is one of the largest inline check valves made. It is equipped with a curved bill design that provides a tight seal with little or no back pressure that enhances sealing around entrapped flood debris, such as tree branches or plastic bags. This feature contrasts with conventional flapper-type check valves that can clog.

Like their predecessors, the Aspen heat exchangers consist of stainless steel tubes extending into copper cooling fins. Deionized water is pumped through the cooling jacket of the laser head and then to the Aspen exchanger to remove excess heat. A fan dissipates the heat into the atmosphere.

Lytron engineers designed a shorter fluid path for the Aspen unit, and increased air fin surface area to better match the unit's liquid side and air side capacities. They also replaced a double row of stainless steel tubes with a single row, enabling them to cut the number of tubes by more than 70 percent, thereby lowering the overall cost of the heat exchanger. Using fewer tubes also reduces the weight of the heat exchanger by 3.9 pounds and shortens its liquid fluid path by 60 percent.

The Aspen has a lower liquid pressure drop than its predecessors, specifically, two pounds per square inch lower at 1.5 gallons per minute. This translates into a smaller and less costly coolant pump.

In addition, engineers redesigned the Aspen Series' fin geometry, increasing its density to provide 21 percent more fin surface area. This design improves the heat transfer coefficient. Fabricating the Aspen's frame and fan plate from a single piece of aluminum further reduced the heat exchanger's cost and weight.

The joints of the Aspen are argon purged during welding to prevent contamination. The return loops of the Aspen tubes are simplified to eliminate crevices that can trap particles that would contaminate the coolant.

One end user of the Aspen heat exchangers is Candela Laser Corp. of Wayland, Mass. Candela Laser manufactures medical lasers that are used in dermatology, ophthalmology, and urology. "We equip our pulse dye lasers, which are used to treat vascular lesions, port wine stains, and other pigmented cosmetic conditions, with the Aspen heat exchangers," said Owen Schirduan, an electrical engineer at Candela Laser.

The Aspen units replaced earlier-generation heat exchangers that were connected to the laser's cooling system. Schirduan credited the Aspen heat exchangers' higher efficiency, and simplified design, low price, and cleanliness, which minimizes maintenance, with "saving our laser manufacturing 40 percent of the cost incurred by the heat exchangers we used previously."

The BWT flowmeter system is installed in pipelines so that fluid passes between its sensors. The sensors contain a bundle of cylindrical elements whose collective tip contacts the fluid without obstructing its flow, preventing a pressure drop.

The BWT flowmeter uses an unobtrusive bundle of elements to transmit a highly concentrated ultrasonic wave into petrochemical fluids.

The flowmeter's transducer transmits a highly collimated beam of ultrasound through the element bundle and into the fluid. Travel times in the returning ultrasonic signal correspond to the flow rate. These changes are detected and analyzed by the BWT's electronics and are downloaded to plant controls.

Panametrics designed the flowmeter to accommodate a variety of petrochemical fluids. For example, when metering viscous, high-molecular weight fluids such as the heavy crude oil residuals in tank bottoms that are solid at room temperature, the BWT flowmeter emits a powerful signal at low frequency ultrasound.

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