Conco NitroLanceTM equipment is stored for easy transportation.
NitroLanceTM liquid nitrogen (LN2) cleaning technology by Conco has proven to be a smart preventative maintenance strategy for a Johnson Matthey diesel catalyst plant in Pennsylvania, where the maintenance staff is committed to good stewardship of process components. Johnson Matthey is a global leader in science, specialty chemicals and sustainable technologies and aims to create cleaner, healthier solutions for a wide segment of industries, including emission control catalyst technologies for diesel engines.
The cumulative benefit of regularly scheduled NitroLance cleanings at this plant was realized at the most recent mobilization, when the full duration of LN2 cleaning was completed ahead of schedule and under budget. Because of preventative maintenance conducted on the air coolers, fouling was quickly remediated. Moreover, because LN2 rapidly evaporates, nothing was left behind except the deposit that was removed. Because no wastewater is produced using LN2, no drying time was required and the equipment was immediately available for service.
Figure 1: Before NitroLanceTM cleaning.
The Conco NitroLance cleaning system delivers pressurized liquid nitrogen (LN2) to the surface of air coolers, heat exchangers and condensers, rapidly removing difficult deposits through three mechanisms of action: thermal/volumetric expansion, mechanical pressure and super-cooling.
- Thermal/volumetric expansion: As the high-density LN2 vapor penetrates the cracks and crevices of the fouling and deposition, it rapidly converts into a gas, expanding nearly 700 times. This rapid expansion, combined with the delivered pressure and cold temperature, causes the fouling deposit to break apart.
- Mechanical pressure: The pressure exerted at the nozzle tip of the NitroLance is regulated from 5,000 psi to 55,000 psi based on the equipment being cleaned and fouling characteristics.
- Super-cooling: The super-cooled LN2 (-160 degrees Fahrenheit to -300 degrees Fahrenheit at the nozzle) facilitates the fracturing of deposits.
The NitroLanceTM cleaning system delivers pressurized LN2 to the surface, rapidly removing difficult deposits.
Figure 2: After NitroLanceTM cleaning.
Cleaning with LN2 is very safe and extremely effective. Extensive evaluations of the effects of LN2 on base metal have been performed to examine possible changes to the metal's grain boundaries and structure. Liquid nitrogen cleaning of basic carbon and stainless steel has caused no micro-structural modifications or changes in the surface micro-hardness of the base metal. Shrinkage or modification of the mechanical properties of the base metal is virtually always avoided because the NitroLance process is performed at a fast rate of speed (greater than 10 feet per minute) and the base metal has only brief contact with the LN2.
For more information on NitroLance and other Conco products and services, visit www.conco.net or contact Beth Foley-Saxon at bfoley-saxon@conco.net.
