Розробка рекуперативного теплообмінного пристрою для екструдера з переробки харчової сировини

Abstract

Розроблено рекуперативний кожухозмійовиковий теплообмінний пристрій для модернізації одношнекового екструдера з переробки харчової сировини. Досліджено процес теплообміну за використання тепла відхідних газів із робочої камери екструдера для підігріву сировини в бункерній сушарці. Розроблено методику з удосконалення технологічної лінії пристроюпрототипу. Визначено конструктивні та економічні витрати на виробництво й експлуатацію теплообмінного пристрою екструдера. На підставі результатів проведено порівняльні розрахунки річного енергозбереження.

Results of research and development of recuperative heat exchanger for upgrading of single-screw extruder, for processing food materials are presented. The process of heat exchange using heat of exhaust gases from the working chamber of the extruder for heating material in the bunker dryer are worked out. As a result, research has been developed continuously operating single-phase countercurrent heat exchanger, which is a chamber with insulation jacket in a cylinder, inside which is coil. Determined the average temperature of the heating of the coolant in the annular gap is Т1sr = 118°C. The temperature of water heated at the outlet of heat exchange tube is Т2'' = 110°C. Determined the optimum temperature drying and heating the raw material is 90–110°C. Methodology of improve technological line of device-prototype was introduced into production. During development design of heat exchange device, thermal and structural layout calculations were conducted. The needed dimensions for modeling of heat transfer surfaces, the height of their location in the body of heat exchanger were obtained from the heat balance equation, previously has been calculated using ratios criterion for single-phase recuperative heat exchanger. Based on the these data were made economic and hydrodynamic calculations. Estimates shows that hydraulic losses in the countercurrent flow stream along the coils are smaller than the traditional using direct flow around the tube bundle which is transversely oriented. As result, heat power and main overall parameters of the heat exchanger were found. Structural and economic costs of production and operation of heat exchanger for the extruder has been estimated. Technical and economic indicators and the annual energy saving were identified for using the upgraded extruder with high energy-saving for processing food materials. Comparative calculations of the annual energy savings are presented.