Development of Innovative Spray Nozzle Design to Reduce Indoor Air Emissions from Aerosol Consumer Products

PACIFIC NW POLLUTION PREVENTION RESOURCE CENTER
POLLUTION PREVENTION RESEARCH PROJECTS DATABASE

Project Name: Development of Innovative Spray Nozzle Design to Reduce Indoor Air Emissions from Aerosol Consumer Products

Date Last Updated: 10/96

Project Summary: Purdue University has developed and demonstrated an innovative spray nozzle design for use with precharged aerosol containers. This design is similar to one previously developed and demonstrated at Purdue for pump and trigger dispensed aerosol products. The new dispenser design allows manufacturers to reformulate selected aerosol consumer products (e.g., personal care, hair care, degreasers, and hard surface cleaners) using water and air in place of VOC solvents and hydrocarbon propellants in precharged systems, while still maintaining acceptable product delivery characteristics. Laser diffraction measurements made at Purdue indicate that the new dispenser design produces product droplets in the desired size range. Data demonstrate that Sauter Mean Diameters (SMDs) are within experimental error of 70 痠 for air to liquid ratios (ALRs) as low as 0.75%. Reducing the ALR below 0.75% results in a rapid increase in the mean drop size. The data also indicate little sensitivity of mean drop size to viscosity over the range considered in this study (0.020 to 0.080 kg/m-s, or 20 to 80 cP). Data also show that air consumption is below target values and supply pressures are acceptable. Dispenser performance is relatively insensitive to product formulation, as described by its viscosity and surface tension. This simplifies manufacturing since a single dispenser design can then be used with a wide array of products.

Current research at Purdue is addressing three questions necessary to provide rational design guidelines to industry. First, when the product exits the dispenser, how does it break up into ligaments and drops? Second, to what extent does the spray entrain surrounding air? Third, what challenges must be met during intermittent nozzle operation? Pulsed holography and PIV are being used to acquire the necessary data to answer these questions.

Design guidelines for the new spray nozzle will be available in 1997.

Project Keywords: aerosol consumer products, indoor air, spray nozzle, VOCs

Organization Performing Research: Purdue University

Primary Research Contact:
Paul Sojka
Thermal Sciences and Propulsion Center
School of Mechanical Engineering
Purdue University
West Lafayette, IN 47907-1003
(317) 494-1536 / FAX: (317) 494-0530
sojka@ecn.purdue.edu

Date Research Started/Completed: 1/94 - 6/97

Publications Based on Research: an EPA Report and technical papers will be available as research progresses.

Approximate Project Budget: $165,000 (FY 94-95)

Primary Project Funder: US EPA, Air Pollution Prevention and Control Division, Indoor Environmental Management Branch

Funder Contact:
Ms. Kelly Leovic
US EPA (MD-54)
Research Triangle Park, NC 27711
(919) 541-7717 / (919) 541-2157 FAX
kleovic@engineer.aeerl.epa.gov