Non-Immersion Ultrasonic Cleaning: An Efficient Green Process for Large Surfaces with Low Water Consumption

Abstract

Ultrasonic cleaning is a developed and widespread technology used in the cleaning industry. The key to its success over other cleaning methods lies in its capacity to penetrate seemingly inaccessible, hard-to-reach corners, cleaning them successfully. However, its major drawback is the need to immerse the product into a tank, making it impossible to work with large or anchored elements. With the aim of revealing the scope of the technology, this paper will attempt to describe a more innovative approach to cleaning large area surfaces (walls, floors, façades, etc.) which involves applying ultrasonic cavitation onto a thin film of water, which is then deposited onto a dirty surface. Ultrasonic cleaning is an example of the proliferation of green technology, requiring 15 times less water and 115 times less power than conventional high-pressurized waterjet cleaning mechanisms. This paper will account for the physical phenomena that govern this new cleaning mechanism and the competition it poses towards more conventional pressurized waterjet technology. Being easy to use as a measure of success, specular surface cleaning has been selected to measure the degree of cleanliness (reflectance) as a function of the process’s parameters. A design of experiments has been developed in line with the main process parameters: amplitude, gap, and sweeping speed. Regression models have also been used to interpret the results for different degrees of soiling. The work concludes with the finding that the proposed new cleaning technology and process can reach up to 98% total cleanliness, without the use of any chemical product and with very low water and power consumption.

Ultrasound and Eco-Detergents for Sustainable Cleaning

“…In a previous paper the same authors [19,22] demonstrate that the combination of ultrasonic vibration with contact angle hysteresis results in a non-return mechanism that expands the droplet (Figure 1) until half the acoustic energy introduced is consumed. The non-return mechanism is therefore related to the advancing, receding and critical sliding angles.…”

Ultrasonic cleaning. Status and prospects

“…Работы [3] и [4] посвящены снижению расхода воды и уменьшению загрязнения сточных вод при ультразвуковой очистке.…”

Research on the Mechanism and Control Strategy of Microbubble Cleaning Sludge

“…Traditional jet cleaning will cause waste of water resources, and chemical cleaning agents may cause secondary pollution, while bubble cleaning has the characteristics of low energy consumption and self-cleaning, which provides a new means for the removal and cleaning of oily sludge [1]. Bubble cleaning is the cavitation of the liquid induced by a cavitation generator and the use of the energy therein to remove surface contaminants [2], cavitation refers to the flow phenomenon of vaporization of the liquid due to a sharp decrease in pressure. The generation, development, and collapse of bubbles in the process of vaporization are often accompanied by dramatic pressure and temperature changes, resulting in significant energy transformations.…”