Miniaturized particle sizer for field application

点击翻译按钮获取中文摘要

Sprays and nozzles are used in a wide range of industries with a variety of applications that include coating, cooling, cleaning, painting and fueling. In all these applications, the spray characteristics impacts an industrial or agricultural process. The characteristics include the spray droplet size, velocity and mass distribution with spray droplet size being the most important characteristics. Droplet size determines the amount of liquid sprayed as a result improper spray can cause significant damage to the process. It can produce excessive amount of valuable material as a poorly operating spray affects the consumption of water and electricity and can decrease the quality of the finished product. The most common methods of non-intrusive measurement of droplet size are: (1) Optical Particle Counter (imaging) (2) laser diffraction analyzer, and (3) Laser or Phase Doppler Velocimetry. Image processing lacks accuracy especially where optical access is difficult to achieve; however, it can be used to characterize a variety of liquid sprays and is relatively simple and low cost. Laser based systems, on the other hand, provide a large amount of accurate data in a short time, however, they are complex and their installation and application is very time consuming. Their use requires a lab environment and specialized training. They are also very expensive devices, therefore, they are mainly used for research purposes and hardly used in the industry as a tool to characterize spray size. The usual protocol is to send the nozzle to a research facility for testing. Currently, there are no method of measuring droplet sizes and velocities in a simple and rapid fashion. Operators rely on visual tests or experientially determined changes before changing a nozzle. However, it is well-documented that a nozzle is defective long before it is detectable. A solution which addresses this would benefit a wide range of industries as well as academia and research centers which do not have access to expensive testing equipment and facility. This work will develop an inexpensive and accurate particle sizing device capable of meeting these needs.