新型石灰窑自动化控制生产线

现代新技术石灰窑就是具有环保、节能功能和机械化、自动化程度较高的现代化石灰窑,采用DCS作为核心控制系统,实时监控并调节控制参数,实现石灰窑生产线的可靠和安全。     

An Experimental Investigation of Lime Juice Drying in a Pilot Plant Spray Dryer

One of the major problems in spray drying of fruit juices such as lime juice is stickiness and thermoplasticity of their compositions. Lime juice consists of invert sugars and citric acid, which have low glass transition temperatures. Due to this characteristic, the particles stick on the dryer wall upon their collision with it. As a result, drying of these materials is very difficult. In order to solve this problem, various percent of silicon dioxide and maltodextrin (DE5), based on total soluble solid content of lime juice, have been used to reach a suitable drying condition. A cool chamber wall spray dryer was used in this investigation in order to decrease the probability of particles stickiness on the wall. Our investigation revealed that an addition of 10% silicon dioxide and 20% maltodextrin (DE5) to lime juice is the optimum amount for a complete and successful drying of lime juice. Sampling of particles from different longitudinal distances in the dryer tower is carried out to find the particle moisture contents as they fly downward in the dryer. The results show a very fast decrease in entrance moisture contents. Based on our experimental data, the variation of moisture contents are presented as a function of radial distance from central line and longitudinal distance from the entrance region.     

不同改良剂对不同含砂率粉土改良性质研究

通过人工室内配制不同含砂率(10%、20%、40%)粉土,对其进行改良试验,研究在不同改良剂(石灰+水玻璃、石灰+粉煤灰)、不同配比作用下3种含砂率粉土的改良效果,研究结果表明:随着含砂率的增加,无论是素土还是改良土,其最大干密度均增大;对于石灰+水玻璃改良土,其最大干密度较素土有明显的降低,而石灰+粉煤灰改良土与之相反;石灰+水玻璃改良土最优含水率与素土略有差别,而石灰+粉煤灰改良土与素土最优含水率基本一致;在同一含砂率下,对于不同配比的石灰+水玻璃改良土,其最大压实度和最优含水率并未发生较大变化,10%石灰+20%粉煤灰的压实度高于其他配比情况;在恒定压实度(95%)下,改良土的无侧限抗压强度明显高于素土的无侧限抗压强度,改良剂对粉土起到一定的"维稳"效果,改良剂掺量才是决定无侧限抗压强度的关键因素。     

常压石灰法处理拜尔法赤泥的研究

采用正交法对影响常压石灰法处理拜尔法赤泥的因素进行研究,结果表明:在CaOf/Na2O赤3 5～4 5、90～95℃、液固比(L/S)3 5～4 0、3～4h条件下,拜尔法赤泥的N/S可由反应前的0 5降到0 2以下,完全满足赤泥直接排放要求。     

冶金石灰竖炉出灰系统的技术分析

概述了传统的石灰竖炉出灰系统的结构及应用现状 ,分析了其存在的问题 ,并介绍了一种新型的由双圆盘与三段阀组成的出灰系统的结构与性能 ,根据国内推广应用情况 ,指出了双圆盘出灰机与三段阀是较为科学的石灰竖炉出灰设备     

电石生产用石灰质量的控制

通过麦尔兹窑生产过程阐述了石灰质量控制的要点。为保证生产出优质石灰,应对原料和燃料的杂质进行控制,同时还应选择合理的石灰石粒度、煅烧温度、压力和煅烧时间。     

Tunnel spoil classification and applicability of lime addition in weak formations for muck reuse

Tunnel construction planning requires careful consideration of the spoil management part, as this involves environmental, economic and legal requirements. In this paper a methodological approach that considers the interaction between technical and geological factors in determining the features of the resulting muck is proposed. This gives indications about the required treatments as well as laboratory and field characterisation tests to be performed to assess muck recovery alternatives. While this reuse is an opportunity for excavations in good quality homogeneous grounds (e.g. granitic mass), it is critical for complex formation. This approach has been validated, at present, for three different geo-materials resulting from a tunnel excavation carried out with a large diameter Earth Pressure Balance Shield (EPB) through a complex geological succession. Physical parameters and technological features of the three materials have been assessed, according to their valorisation potential, for defining re-utilisation patterns. The methodology proved to be effective and the laboratory tests carried out on the three materials allowed the suitability and treatment effectiveness for each muck recovery strategy to be defined.     

Strength,sorption and abrasion characteristics of concrete using ferrochrome ash (FCA) and lime as partial replacement of cement

This paper presents the results of experimental investigations and microstructure study carried out to evaluate the possibility of utilization of ferrochrome ash (FCA), a waste product from ferroalloys industries for partial replacement of cement in concrete preparation. FCA is used in four different substitution rates such as 10, 20, 30 and 40% along with 7% lime. Various strength and durability tests were conducted to understand the effects of FCA and lime on performance of concrete. Test results revealed that replacement of cement by FCA in various % with 7% lime enhanced the 28 days compressive strength 1.5–13.5%, flexural strength 4.5–9%, bond strength 15–29%, abrasion resistance 10–23% and reduced the sorptivity 25–43%. The concrete containing 40% FCA and 7% lime, replacing 47% of ordinary Portland cement (OPC) in total, exhibited strength of normal concrete or even more at all ages. XRD and petrography studies confirmed the results of mechanical and durability properties.     

石灰窑用变频器调试两个常见问题的分析

通过对石灰窑用变频器调试过程中两个常见问题的分析,查出了设备出现故障的原因,并采取相应措施得以解决,保证了石灰窑顺利投产。     

石灰窑耐火材料脱落原因及改进措施

分析了石灰窑耐火材料脱落原因,采取了重新选择耐材材质、设计砖型、新型隔热材料应用及改进措施等,实现了石灰窑耐火材料使用寿命的延长,使石灰窑筒体煅烧带表面温度降低到350℃以下,最终降低了石灰生产成本。