Concept Development of a New System for Drying Dishware : Degree project for Bachelor of Science in Innovation and Design Engineering

Abstract: The Drying of dishware inside a dishwasher is the phase in the washing cycle that uses the most energy and is therefore the phase with most room for improvement as regards on energy usage. When drying the dishware through closed air circulation, it is the temperature of the final rinse that determines the heat available during the drying process. If heat from the final rinse is to be used more efficiently, how could such a concept of drying be developed? The project was directed as a process for product development. To gain a better understanding of the problem, the project started with a pre study which include the issues: how does drying with air work, how is drying done in today’s dishwashers, how does other industries solve this problem? The pre study is later summarized in a requirement specification, that describes what demands and wishes there are for the concept. To easier understand the big complex problem, it was branched out into smaller sub problems, with the goal of coming up with ideas for each sub problem, and later combine them into concepts using a morphological matrix. With the requirement specification as a starting point, ideas were generated for each sub problem, with the creative methods brainstorming, brainwriting and SCAMPER. The chosen solution consists of a tray combined with a system of air circulation. The tray is drawn up under the upper basket from the side of the dishwasher. It then collects the water dripping down from the dishes above, preventing the water from dripping onto the lower basket, and therefore leaving less water on the dishes below. Thereafter the tray is retracted when the water is done dripping, and the water runs off the tray, along the wall. The air circulation is then activated and directed from the top towards the bottom. This removes the leeward between the dishware and the basket that otherwise appears because the air reaches the basket first. The air circulation system is designed with the risk of flooding in mind. That resulted in a drainage system that traps all the water that manages to get inside the system and drains it back into the washing space. Further, ribs were integrated into the inlet to prevent the water from spraying straight into the system. The ribs also help spread the air where it is needed.