Heat And Mass Transfer Analysis And Heat Pipe Drying Scheme For Drying In Molded Pulp Mold

Pulp molded products are a new type of packaging materials,and as a substitute for plastics,they are increasingly welcomed by the society.The vigorous development of pulp molded products meets the requirements of building a resource-saving and environment-friendly society.Drying,as the most important process for the production of molded pulp products,focuses on improving the thermal efficiency of the drying process,reducing heat loss and drying time,and is of great significance to the development of the pulp molding industry.In this paper,the drying process of pulp-molded products was studied.The heat and mass transfer of the pulp-slab during the drying process was analyzed,and a drying scheme for the pulp-molded heat pipe mold was proposed.The following is the main research work:Firstly,this paper analyzes the drying process of pulp molding,and the main reason for drying mechanism is to remove free moisture.By comparing the two major types of drying methods for pulp molding,it can be seen that the method of drying inside the hot press mold can not only be Improve product quality,but also improve thermal efficiency and greatly reduce energy consumption.Secondly,using the comprehensive transfer process principle of heat and mass transfer to analyze the mechanical properties of the pulp in-mold drying,the moisture drying speed can be significantly improved under vacuum conditions,in which the unit mass(1 kg)of wet pulp blank is dried from the mold.The discharged water is about666.67 g,the required heat consumption is 2000 kJ,and the average drying speed of the hot press drying is about 44.44 g/s.Then,using the theory of heat pipe technology,combined with the drying of the pulp molding hot press,a drying scheme for the pulp molded heat pipe mold was proposed,and a sketch of the pulp molded heat pipe mold was designed.According to the dryingconditions of the pulp molding products by the company,the aluminum ammonia heat pipe is selected as the main body of the heat pipe mold,which can not only improve the heat efficiency of drying,but also ensure good compatibility,which is conducive to the safety and efficiency of the hot press equipment's produce.Finally,the experimental scheme of the pulp-molded heat pipe mold was designed,and the liquid-filled quantity of the heat transfer working medium of the aluminum-ammonia heat pipe mold was calculated.The relevant design of the heat pipe mold was performed.The wall thickness of the heat pipe mold was 5 mm,and the sealing bolts were connected by 6 bolts whose type are 8mm.In order to evaluate the heat transfer performance of the heat pipe mould,the phase change heat transfer of the heat transfer working medium inside the heat pipe was analyzed,and the heat transfer area of the boiling section and the temperature difference of the condensing section were estimated.