DuPont Merck
Pharmaceutical Company Uses Ultrasound
to Replace Chemical Solvents in Tank
Cleaning
Chemical and pharmaceutical companies have
typically used chemical solvents to clean tanks. These traditional techniques
depend on dissolving or emulsifying contaminants in a solvent to provide the
cleaning action. These methods use solvent rinsing or multiple solvent
distillations to clean process tanks and reactors. Solvents used include
methanol, ethanol, methylene chloride, and isopropanol, all of which emit volatile organic substances
during both the cleaning and the subsequent incineration of the waste.
Companies now how have a more
environmentally-friendly, energy-efficient option. They can use the power of
sound to clean large industrial tanks. Through a cost-shared demonstration
project sponsored by the U.S. Department of Energy's NICE3 (National
Industrial Competitiveness through Energy, Environment, and Economics) Program,
TELSONIC Ultrasonics adapted ultrasonic technology to
generate bubbles in fluid-filled tanks, thus cleaning inner surfaces without
solvents, emissions, or manual labor for the DuPont Pharmaceuticals Company.
The purpose of the NICE3 Program
is to champion technological advances that don't receive the encouragement and
visibility that they should because low energy prices offer little motivation
for innovation. This program works with the most waste- and energy-intensive
industries in the
This project yielded energy savings on the
order of ~237.23M kJ (224.85M Btu) per 758-L (200-gal) tank and annual cost
savings of ~USD 35,000 per tank.
Each tank system consists of a tube
resonator that uses an integrated ultrasonic transducer and rod-shaped tubular
ultrasonic resonator that enters the water-filled tank via a top opening. The
transducer and resonator vibrate at 20,000 times/second,
creating high- and low-pressure zones that form tiny bubbles. These bubbles
grow to a specific diameter and then implode violently, providing an intense
scrubbing action on the inner surfaces, agitator blades, and bottom valves.
These bubbles are small enough to penetrate microscopic crevices, making the
process superior to traditional methods. This method eliminates cleaning
solvents and associated wastes and reduces energy and labor costs.
When comparing this method to a typical
distillation cleaning for an average 758-L (200-gal) tank, savings on the order
of 1.240M kJ (1.175M Btu) are realized. Additional
savings of ~1.041M kJ (987K Btu) result from reduced methanol usage. For an
average system, the annual savings are ~237.23M kJ (224.85M Btu).
When considering the savings, the reduced
use of methanol and reduced downtime must be considered as this method is
considerably less time consuming than the traditional solvent cleaning method.
So the annual energy savings per 758-L (200-gal) tank system equate to ~USD
350,000 Given the cost of the cleaning system, it takes only eight cleaning
cycles (~4 weeks) to pay for a 758-L (200-gal) tank system.
By eliminating the use of chemical solvents
in the cleaning process, no volatile organic substances are emitted. The
resulting need for waste disposal (via incineration) is also eliminated.
Contacts:
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DuPont Merck
Pharmaceutical Company Chambers Works Process
Research Facility Deep 865-299-1100 |
TELSONIC Angelo C. Piro 800-691-3111 865-241-0741 (Fax) |
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