环模特性对饲料颗粒成型率影响探究试验

为提高饲料颗粒成型率和环模制粒机的制粒效率,结合生产实际,设计了三因素三水平正交试验,探究环模模孔长径比、有效高度和转速对饲料颗粒成型率的影响。结果表明:环模结构中模孔长径比对饲料颗粒成型率影响最大,其次是环模转速,环模高度对饲料颗粒成型率的影响效果最小;饲料颗粒成型率最高的优化组合方案为模孔长径比11、环模转速330 r/min、环模高度130 mm。探究结果可为后续改进制粒机结构、提高饲料颗粒质量、减少制粒机关键部件磨损、降低加工成本提供新视角和新方法。

环模制粒机的主要技术参数

1前言 环模制粒机是颗粒饲料生产中的关键设备,它将配合好的各种粉状饲料压制成颗粒,改变了饲料的物理性能和生化性能,提高了饲料利用率和喂养适口性,是现代化饲料厂必不可少的重要设备.因此,制粒机性能优良与否就直接影响颗粒饲料的品质,这要求在设计或选用制粒机时要注意它的几项主要技术参数.

不同工艺参数下苜蓿草粉环模制粒机流场的模拟与验证

环模制粒成型技术以其高效率、高成型率、强适应性等优点广泛应用于生物质能源和饲料产业等领域。该文以苜蓿草粉为原料,应用POLYFLOW软件对环模制粒机挤压区流场进行数值模拟,研究了喂料量、环模转速和物料含水率的变化对流场压力、速度、剪切速率和黏度分布特性的影响规律,并以试验验证,旨在为生产工艺的有效控制提供参考依据。结果表明:在结构参数等条件一定的情况下,增大喂料量,流场压力升高,挤压成型区域扩大,且物料以较快的速度作层流运动,流场剪切速率降低,黏度增大,出模压力和成型密度较大;减小环模转速,流场压力和挤压成型区增大,流动速度减小,剪切速率降低,黏度较大,但出模压力和成型密度降低;物料含水率降低使流场压力、黏度、出模压力和成型密度增加。通过比较得出:当喂料量为6 t/h、环模线速度为6.5 m/s和物料含水率为15%时所形成的流场有利于苜蓿草粉的制粒成型。

Numerical Simulation on a Throttle Governing System with Hydraulic Butterfly Valves in a Marine Environment

Hydraulic butterfly valves have been widely applied in marine engineering because of their large switching torque, low pressure loss and suitability for large and medium diameter pipelines. Due to control problems resulting from switching angular speeds of the hydraulic butterfly valve, a throttle-governing control mode has been widely adopted, and detailed analysis has been carried out worldwide on the structural principle concerning speed-regulation and the load torque on the shaft while opening or closing a hydraulic butterfly valve. However relevant reports have yet been published on the change law, the error and the influencing factors of the rotational angular velocity of the hydraulic butterfly valve while opening and closing. In this article, research was based on some common specifications of a hydraulic butterfly valve with a symmetrical valve flap existing in a marine environment. The throttle governing system supplied by the accumulator to achieve the switching of the hydraulic control valve was adopted, and the mathematical models of the system were established in the actual conditions while the numerical simulations took place. The simulation results and analysis show that the rotational angular velocity and the error of the hydraulic butterfly valve while switching is influenced greatly by the drainage amount of the accumulator, resulting in pressure loss in the pipeline, the temperature of hydraulic medium and the load of the hydraulic butterfly valve. The simulation results and analysis provide a theoretical basis for the choice of the total capacity of the accumulator and pipeline diameters in a throttle governing system with a hydraulic butterfly valve.It also determines the type and specification of the hydraulic butterfly valve and the design of motion parameters of the transported fluid.