Design And Application Of In-situ Restaurant Food Waste Dehydrator

With the continuous advancement of urbanization and the rapid development of catering industry in China,the suitable disposal of restaurant food waste has become an urgent problem.However,due to its high moisture content,the recycling and treatment of restaurant food waste cost a lot.Therefore,it is necessary to perform in-situ dehydration treatment on restaurant food waste right after its generation,which helps to reduce the collection and transportation costs,as well as improve its recycling and treatment efficiency.In order to meet catering industry’s needs for in-situ dehydration of restaurant food waste,a new equipment that occupies a small space,has high efficiency and low energy consumption,and can deal with complex materials is needed.In view of this,a survey about restaurant food waste generation sources,such as restaurants,hotels,and canteens,was conducted in Hangzhou.Based on it,an in-situ restaurant food waste dehydrator was designed and installed,and an empirical experiment was conducted.The main findings are as follows:（1）The situation of restaurant food waste generation sources as well as the physical and chemical properties of typical restaurant food waste were analyzed systematically.Thus,the key factors restricting in-situ dehydration of restaurant food waste were identified.The results showed that the per capita production of restaurant food waste was 0.71～0.98 kg·d^-1,and the remaining space in kitchen only accounts for 23.1%～28.4%.Restaurants,hotels,and canteens lacked food waste pre-treatment conditions such as impurity removal,crushing,and deoiling.The moisture content and oil content of typical restaurant food waste were about 77.60%and 7.80%,the content of hard impurities was 2.1%～13.9%,and the proportion of materials whose particle size were greater than 1 cm was 74.9%.Uneven particle size,high content of hard impurities,and high percentage of moisture with dehydration difficulty were the key problems in in-situ dehydration of restaurant food waste.（2）Based on the idea of rotating the net filter to dehydrate the materials inside,an in-situ restaurant food waste dehydrator with high fitness,high efficiency,and low energy consumption was designed.Through a test on the manual-version mockup of the dehydrator,it was calculated that its energy consumption was less than 1.5k W·h·t^-1,and its area occupation was only 0.38 m².After treatment,the dehydration rate of the materials reached 57.0%,and the loss rate was 1.4%.With the help of Solid Works and ANSYS,models of the dehydrator’s components were constructed,followed by finite element analyses.The analysis results showed that the strength and rigidity of the dehydrator meet the requirements.（3）An in-situ restaurant food waste dehydrator was installed according to its parameters and model.And its optimal operating condition was determined,using typical restaurant food waste.The experiment results showed that,under the premise of processing timely and non-reversing the net filter,when the net filter rotated 5 r and the pressure retention time was 120 s,the dehydrator was in the optimal operating condition.Then the dehydration rate of the materials was 69.6%,the loss rate was1.6%,and the reduction of restaurant food waste reached 56.0%.The operation effect of the dehydrator achieved its design requirements.