过磷酸钙折流混合器的改进

由于绿原化工有限公司过磷酸钙装置生产能力由 6 70 t/ d(实物量 )提高到 84 0 t/ d,折流混合器负荷增大 ,出现折流环磨损加快等问题。采用若干技改措施 :扩大折流环内径、改变折流混合器喷射方向、采用新材料制作折流环 ,使折流混合器能满足 84 0 t/ d过磷酸钙生产的需要     

过磷酸钙含氟尾气处理的新方法

对动态泡沫床处理过磷酸钙含氟尾气的有关技术及费用作了说明 ,指出该方法费用高 ;提出一种新方法 ,该方法不加任何化学助剂 ,采用水作吸收剂 ,只需改变动态泡沫床一些设计参数和选用一种特殊的喷头 (喷头周围设计 1个圆锥形死角区 ,使含氟气体不可能进入该区 )避免了硅胶堵塞。该方法已在湖南浦市化工总厂运行 1年多未发现堵塞 ,同时该法投资少、能耗低、排放尾气达标     

A discussion of the methods for comparing the relative effectiveness of phosphate fertilizers varying in solubility

Because various phosphate (P) fertilizers differ widely in their solubility, it is commonly observed that crop response to P fertilizers varies under the same soil and crop conditions. Furthermore, a major problem encountered in the methods for determining the relative effectiveness (RE) of water-insoluble P fertilizer (e.g., phosphate rock) with respect to water-soluble P fertilizers, e.g., single superphosphate (SSP) and triple superphosphate (TSP), is that their growth response curves are usually nonlinear and often do not share a common maximum yield. In this paper, we review and discuss the advantages and disadvantages of the three most commonly used methods for calculating the RE of phosphate rock with respect to TSP (or SSP). The three methods are vertical comparison, horizontal (substitution rate) comparison, and linear-response comparison.     

Characterizing Strong Stability Preserving Additive Runge-Kutta Methods

Space discretization of some time dependent partial differential equations give rise to ordinary differential equations containing additive terms with different stiffness properties. In these situations, additive Runge-Kutta (additive RK) methods are used. For additive RK methods the curve of absolute monotonicity gives stepsize restrictions for monotonicity. Necessary conditions for nontrivial curves of absolute monotonicity are the nonnegativity of the additive RK coefficients and some inequalities on some incidence matrices. In this paper we characterize strong stability preserving additive Runge-Kutta methods giving some order barriers and structural properties. Research supported by the Ministerio de Educación y Ciencia, Project MTM2005-03894.     

磷酸酸泥在过磷酸钙生产中的利用

介绍26%～28%中低品位磷矿加磷酸酸泥生产一级品过磷酸钙的技术.生产试验表明,在过磷酸钙生产过程中添加1.5～3.5m3/h的酸泥,可使最终产品w(P2O5有效)提高到16.5%左右,每吨产品硫酸消耗减少30～40kg,使用26%～28%品位磷矿石可生产出一级品过磷酸钙.     

聚酯纤维固相缩聚和拉伸试验研究

对聚酯纤维进行固相缩聚,分别进行了纤维在松弛状态下和在紧张状态下的固相缩聚试验,成功制取了卷绕状态下的高黏度聚酯纤维,纤维特性黏度达到1.003dL/g。通过对这种高黏度聚酯纤维的拉伸试验,制取了强度达到7.03cN/dtex的高强纤维,而对比实验的纤维经过拉伸,强度只有5.40cN/dtex。     

我国低浓度磷肥的发展策略和过磷酸钙生产的技改方向

从我国磷矿资源以中低品位磷矿居多,低浓度磷肥本身含有作物所需中微量元素,低浓度磷肥制造成本低及我国农民长期的使用习惯,论述低浓度磷肥在我国存在的必要性。过磷酸钙企业目前存在规模小、分散、生产技术落后、污染严重、废弃物利用率低等问题,提出过磷酸钙生产的技改方向,如无熟化造粒技术,采用浓酸矿浆法并同时采用集散微机自控技术,主要设备实行定型化、系列化等,以增强企业的竞争力。     

过磷酸钙生产中排氟风机防腐结构改进

40万t/a化成法生产过磷酸钙,采用4 72 10 N o12.5离心式钢衬胶排风机,该风机使用中出现泄漏、腐蚀等问题,经对上下机壳密封方法、清理门结构等的改进,使风机检修工作量大大减少,风机寿命延长。     

气相色谱法测定过磷酸钙中三氯乙醛

过磷酸钙中的三氯乙醛用异丙醇提取,采用气相色谱法、微电子捕获检测器(ECD)进行测定。该方法具有快速、简单、灵敏度高等优点,适合过磷酸钙中三氯乙醛的测定。     

HOLLiAS-MACS系统在固相缩聚装置中的应用

介绍了一种国产DCS系统在固相缩聚生产中的应用实例,给出了控制系统的硬件组成及软件实现方法,能够保证装置安全、稳定运行,从而可节省项目投资.