并流喷雾干燥塔的计算机辅助设计研究

Study on the computer-aided design of cocurrent spray dryer

喷雾干燥广泛应用于众多工业品的生产。图解积分法是目前求喷雾干燥塔塔径和塔高常用的方法,但是图解积分法计算过程繁琐,误差大且无法编程计算。因此将喷雾干燥塔中雾滴运动的阻力系数与雷诺数之间的关系用误差极小的多项式取代图解积分法中使用的误差较大的Allen 公式,并给出了喷雾干燥塔塔径和塔高的积分式,利用四阶复化高斯—勒让德数值积分法计算喷雾干燥塔塔径和塔高,有效地提高了设计精度,利用可视化语言Visual Basic 6.0开发计算机辅助设计软件。算例表明:计算机辅助设计方便、结果精确,为进一步实现并流喷雾干燥塔的优化设计提供了一个有效的设计方法与手段。同时建立以年总费用为目标函数的并流喷雾干燥塔经济评价模型,对并流喷雾干燥塔的设计参数如空气进出口温度、空气进口湿度等参数进行经济评价与分析,探讨其对并流喷雾干燥塔运行费用与年总投资的影响,对实现并流喷雾干燥塔的优化设计,降低能耗,节省投资具有一定的参考价值。

The spray dry had been adopted widely in industry process.At present,the diagram integral was common method to calcu-late the diameter and height of the spray dryer.This method was loaded down with trivial details,less accurate and was not calculatedin a computer.Instead of the equation Allen the polynomial was used to describe the relation between drag coefficient and Renault num-ber of fogdrop moving in the spray dryer.The integral formulas of diameter and height of spray dryer were present.The diameter andheight of the spray dryer were attained by fourth order Gauss—Legendre numerical integral method.The software of computer-aided de-sign was development by Visual Basic 6.0.The practical example indicated that the diameter and height of the spray dryer was calcu-lated easily and accurately by computer-aided design which provided an effective design method for the optimum design of cocurrentspray dryer.The economic evaluation model of cocurrent spray dryer was established.The economic evaluation and analysis were madeon air inlet temperature,air outlet temperature,air inlet moisture and so on.The effect of design parameters on running expenses andannual total investment of the spray dryer was discussed,which provided theoretic basis for optimum design of spray dryer.he eco-nomic evaluation and analysis had reference value for decreasing energy consumption and saving investment.