"胶乳法"氯化天然橡胶薄层干燥影响因素的研究

采用二次回归正交设计方法,对“胶乳法“氯化天然橡胶(CNR)进行薄层干燥试验.分析了热风温度、风速和物料的粒径等因素对干燥速率、干燥后物料性能的影响规律,确定了影响物料薄层干燥速率各因素的主次,提出了较佳的干燥工艺和合理的性能参数.     

干燥工艺参数对颗粒状氯化天然橡胶干燥过程的影响

通过氯化天然橡胶的穿透干燥试验,探讨风温、风速以及粒径对CNR干燥速率的影响规律,通过对数据正交分析,寻找最佳干燥工况及参数,揭示影响干燥速率的规律。     

微波干燥天然橡胶含水量与干燥速率关系研究

为探讨湿天然橡胶微波干燥新技术,利用自制的微波干燥试验测试系统,对湿天然橡胶进行了不同干燥温度下的微波干燥试验,测试分析了微波干燥过程中湿天然橡胶含水率与失水率的关系,并探讨了不同干燥温度下湿天然橡胶含水率与失水率的关系。研究结果表明,不同干燥温度下湿天然橡胶失水速率随干基含水率的变化曲线呈一致趋势;失水率随含水率的升高先增大后减小;干燥温度越高,湿天然橡胶相同失水率下对应的含水率就越高。     

小颗粒“胶乳法”氯化天然橡胶穿透干燥试验

通过氯化天然橡胶(CNR)的穿透干燥试验,探讨风温、风速以及粒径对“胶乳法”CNR干燥速率的影响规律,结果表明,温度和风速对含水量的下降速率影响较大,而粒度对其影响较小。建立了穿透干燥方程,对实验数据进行了拟合,结果显示其吻合性较好。红外光谱分析以及物理性能测试结果表明,“胶乳法”CNR物料的干燥温度应控制在100℃以下。     

江苏制成氯化天然橡胶涂料

江苏石油化工学院采用天然橡胶经降解、抓化、脱溶、干燥等步骤制得抓化天然橡胶产品。利用氛化天然橡胶制成的涂料具有耐酸、耐碱等特点,且漆膜牢固,光泽性好,现已成为防腐涂料市场不可替代的产品。产品经上海开林造漆厂试用,确认已达到国内先进水平。江苏制成氯化天然橡胶涂料@毛麒瑞     

天然橡胶的化学改性

介绍了天然橡胶的环氧化改性和氯化改性,天然橡胶的氢氯化、氢化、环化和接枝改性及热塑性天然橡胶等研究。     

专利配方

"胶乳法"工艺生产的氯化天然橡胶复合热稳定剂一种"胶乳法"工艺生产的氯化天然橡胶用热稳定剂组合物,它包括有机锡化合物、咔唑化合物和亚磷酸酯。作为"胶乳法"工艺生产的氯化天然橡胶的热稳定剂体系,它与"胶乳法"工艺生产的氯化天然橡胶混匀,可使"胶乳法"工艺生产的氯化天然橡胶的热稳定性大大提高,起始热降解温度可提高20℃至50℃。(CN1560122)     

氯化橡胶生产技术进展

1前言1 氯化橡胶是由天然或合成橡胶经氯化改性后得到的橡胶状衍生产品.目前氯化橡胶产品有氯化乙丙、氯化聚氯丁二烯、氯化丁基橡胶、氯化聚丁二烯等.但多数情况下,氯化橡胶指氯化天然橡胶.本文论述的正是氯化天然橡胶.     

“胶乳法”工艺生产的氯化天然橡胶复合热稳定剂

一种“胶乳法”工艺生产的氯化天然橡胶用热稳定剂组合物,它包括有机锡化合物、咔唑化合物和亚磷酸酯。作为“胶乳法”工艺生产的氯化天然橡胶的热稳定剂体系,它与“胶乳法”工艺生产的氯化天然橡胶混匀,可使“胶乳法”工艺生产的氯化天然橡胶的热稳定性大大提高,起始热降解温度可提高20℃至50℃。（CN1560122）     

氯化天然橡胶的结构与氯化机理

介绍了有关氯化天然橡胶的氯化机理和结构，以及氯化天然橡胶降解机理及稳定性，并对有关工作的发展动向进行了综述。     

Simulation of Drying Using a Kiln Model

A mathematical model was developed for simulating a convective batch lumber drying process. The model incorporates mass and heat transfer relationships within the lumber stack, as well as thermodynamic properties of the wood and drying air. It takes into account the change of air properties along the stack and its effect on the mass and heat transfer parameters. The model relies on a drying rate function that is an empirical correlation based on single-board tests. A drying rate function for western hemlock (Tsuga heterophylla) lumber was developed. The drying rate function was obtained based on experiment results from 500 small boards dried over a range of conditions used in commercial practice. The model was first validated against data available in the literature and then against large batches of hemlock dried in a laboratory kiln. In both cases, the model output was in good agreement with the average moisture content, the drying rates, and the temperatures measured in the larger batches.     

二醋酸纤维干燥动力学模型

以研究二醋酸纤维干燥动力学为目的,实验测定了空气温度55￣75℃,单位物料量2￣4kg/m2,物料初始含水量37%￣126%,三水平三因素对干燥速率的影响。通过模型比较,得出适合二醋酸纤维的干燥模型为Page方程,模型计算值与实验值吻合较好。该模型可用来预测二醋酸纤维在干燥过程中的水分变化。     

Simulation and Validation of Microwave-Assisted Fluidized Bed Drying of Soybeans

A general mathematical model of heat and mass transfer was developed to simulate the microwave-assisted fluidized bed drying of bulk grain. The model was solved using the well-known Runge-Kutta-Gill method. The model is capable of predicting the moisture content of soybean as well as the drying air parameters (i.e., drying air temperature and moisture content) during drying. The values of mean relative deviation (MRD) were less than 8 and 10% for prediction of grain moisture content and outlet air parameters, respectively, which reflects an acceptable accuracy. In comparison with conventional fluidized bed drying of soybean, microwave-assisted fluidized bed drying led to 83.39–98.07% savings in drying time and 82.07–95.22% savings in specific energy consumption when reducing soybean moisture content from 18.32 to 12% (db).     

A Model for Through Drying of Tissue Paper at Constant Pressure Drop and High Drying Intensity

A mathematical model for through drying of paper at constant pressure drop was developed. The model is based on physical properties; hence, basis weight, pressure drop, drying air temperature, pore size distribution, initial gas fraction, and tortuosity are important input parameters to the model. The model was solved for different combinations of the variables basis weight, drying air temperature, and pressure drop corresponding to industrial conditions and the results were compared with data from bench-scale experiments. The simulations show that the drying rate curve is very sensitive to the air flow rate and that correctly modeling the correlation between pressure drop and air flow rate is the most important factor for a successful model for through drying. The model was tuned by adjusting the parameters initial gas fraction and tortuosity in order to give the best possible fit to experimental data. For a given basis weight and pressure drop, different drying air temperatures resulted in relatively constant values of the fitted parameters. This means that the model can well predict the effects of changes in drying air temperature based on a tuning of the model performed at the same basis weight and pressure drop. However, for a given basis weight, an increase in pressure drop yielded fitted parameters that were somewhat different; i.e., a lower initial gas fraction and a higher tortuosity, a change that increases the resistance to air flow. This implies that the correlation between pressure drop and air flow rate in the model does not quite capture the nonlinear relationship shown by the experiments.     

A Model for Through Drying of Tissue Paper at Constant Pressure Drop and High Drying Intensity

A mathematical model for through drying of paper at constant pressure drop was developed. The model is based on physical properties; hence, basis weight, pressure drop, drying air temperature, pore size distribution, initial gas fraction, and tortuosity are important input parameters to the model. The model was solved for different combinations of the variables basis weight, drying air temperature, and pressure drop corresponding to industrial conditions and the results were compared with data from bench-scale experiments. The simulations show that the drying rate curve is very sensitive to the air flow rate and that correctly modeling the correlation between pressure drop and air flow rate is the most important factor for a successful model for through drying. The model was tuned by adjusting the parameters initial gas fraction and tortuosity in order to give the best possible fit to experimental data. For a given basis weight and pressure drop, different drying air temperatures resulted in relatively constant values of the fitted parameters. This means that the model can well predict the effects of changes in drying air temperature based on a tuning of the model performed at the same basis weight and pressure drop. However, for a given basis weight, an increase in pressure drop yielded fitted parameters that were somewhat different; i.e., a lower initial gas fraction and a higher tortuosity, a change that increases the resistance to air flow. This implies that the correlation between pressure drop and air flow rate in the model does not quite capture the nonlinear relationship shown by the experiments.     

正交试验优选磷酸二氢钾料液喷雾干燥工艺

用正交试验法对磷酸二氢钾料液喷雾干燥的工艺进行优选,以磷酸二氢钾粉末中的水分和干燥损失率为指标,选用L9(34)正交试验表进行正交试验。结果表明:磷酸二氢钾料液喷雾干燥的最佳工艺条件为料液浓度18%、进风温度180℃、进料量120mL/h和压缩空气流量10L/min。在此条件下,磷酸二氢钾损失率最低。     

COMPUTER SIMULATION ON INTERMITTENT DRYING OF ROUGH RICE

This study applied a partial differential equation model with newly-developed thin layer equations to simulate batch re-circulating dryers under different drying conditions, which are combinations of four parameters: drying air temperature, drying air absolute humidity, drying period duration, and tempering period duration. The moisture change and the drying rate, which were of particular concern with respect to the simulated data, were investigated. Validation drying tests were carried out in a lab scale re-circulating rice dryer. Two sets of experiment were performed involving different drying parameters to simulate re-circulating rice dryers which are extensively used in Asian countries. Comparing these two experimental data with two simulated drying curves respectively, it revealed they are quite consist with each other under the same drying conditions. Drying air temperature, drying air humidity, drying period duration and tempering period duration significantly influenced the drying rate. Under the same drying condition, the tempering period duration effect was insignificant to the drying rate in drying zone as the drying air humidity or temperature increased. And, a higher initial moisture content obtained higher time and energy efficiency for the re-circulating rice dryers.     

明胶热风干燥特性的实验研究

采用静态法研究了明胶的平衡含湿质量分数,得到了20℃下吸湿和解吸等温线,结果表明,当空气相对湿度在16%—39%,存在吸湿滞后现象。在对流干燥实验台上进行了明胶干燥特性的实验,以不同厚度的明胶块为实验对象研究了热风温度、风速、湿度对干燥过程的影响。实验结果表明:明胶的干燥过程只有降速阶段,提高热风温度、加大风速均可以在前期提高干燥速率,但在干燥后期干燥速率反而降低;明胶块中心温度受胶块厚度、热风温度影响较大,而在实验范围内空气相对湿度的变化对明胶中心温度影响甚微;明胶的相对含湿质量分数随时间呈指数规律下降,提高风温、加大风速后明胶含湿质量分数在开始阶段下降较快,但最终含湿质量分数反而偏高。