A Pollution Free Aerosol Dispenser

This project involves the development of a consumer aerosol dispenser that seeks to eliminate the volatile organic compound (VOC) solvents and hydrocarbon (HC) propellants used in many commercial sprays. The two distinguishing features of the dispenser are: (1) application of ligament-controlled effervescent atomization for producing very small droplets independent of the fluid viscosity, and (2) a microlaminated nozzle to control both the Sauter mean diameter and the distribution of drop sizes. These two features allow for the elimination (reduction in certain applications) of VOC carrier liquids and HC propellants in conventional aerosol dispensers. For consumer products, large droplets in the spray can cause excessive wetting, while small droplets are easily inhalable. Therefore, it is crucial to achieve a narrow drop size distribution, particularly under transient injection. The targeted drop size by the consumer spray industry is approximately 50 ¿m. During a prior Phase I project, En'Urga, Inc., found that the injector was successful in providing drops that had a mean drop size of approximately 50 ¿m with a very narrow distribution. The advantage of using effervescent atomization is that the injectors are expected to be insensitive to fluid properties. The major task for the present Phase I work is to design and fabricate a prototype aerosol container. During the Phase II work, commercially available products that contain VOCs will be sprayed using nitrogen, rather than hydrocarbon propellants, and reformulated products (which are dissolved in nonpolluting carriers) will be sprayed using nitrogen.