The Development of Standard Agitator Conditions for Effective Performance of a Batch Crutcher in the Frame of Semi-Boiled Process

Abstract

Abstract The saponification reactor, otherwise called the crutcher is a dual purpose unit operational vessel that serves for reactor and mixer in the production of soapy detergent. Little or no efforts have been made by available literatures to work on the crutcher agitation concepts and geometry which determines the rate of reaction and degree of homogeneity of reactor mixture in the crutcher as used in the currently most widely applied semi-boiled process. This paper presents for the first time the standard optimum agitation conditions for effective performance of a crutcher for semi-boiled laundry soap production. A standard reactor volume to diameter of 0.17 m3/m and height to diameter ratio of 1.2 ratios on 7 % over design, agitator speeds of 0.75 rps (paddle), motor power of 10.5 W and torque of 2.24 Nm with impeller to reactor diameter of 1/3 and teflon shaft centralizer have been developed. The introduction of “bottom scrapper” component to the agitation unit in a cone bottomed cylindrical batch reactor would enhance mixing and heat transfer, eliminate recycling unit and the application of under steam bubbling for effective cone content mixing. Also, the introduction of 4 baffles on 0.5 × 10–2 m clearance from impeller blades would promote efficient mixing and heat transfer. The overall conditions developed ensured effective mixing, heat transfer and high rate of reaction.