连铸二冷喷嘴特性试验研究

本文对国内某钢厂板坯连铸机使用的两种喷嘴进行了冷态性能的试验研究。测定了不同喷水条件和喷水压力下的水流分布,可以为生产喷嘴及设计二冷制度提供更合理的参数。     

连铸二冷区喷嘴冷态特性的研究

本文对不同结构喷嘴的冷态特性进行了研究。测定了不同喷水条件下喷嘴的水流.密度分布、喷射角度及水滴尺寸,介绍了水滴速度的计算方法。并讨论了喷水条件和喷水参数对冷态特性的影响。     

连铸喷淋结晶器的冷态实验

研究了连铸喷淋水冷结晶器的实用喷嘴，考察了喷嘴的水流密度分布，喷射角度，水滴速度等水力特性参数。给出了喷嘴群在结晶器上的布置方式及合理的水流密度分布曲线。     

连铸二次冷却喷嘴的检测研究

本文主要论述连铸二冷喷嘴的类型、喷雾方法对铸坯冷却的影响 ,各类喷嘴冷却的优缺点 ,以及环型喷嘴嘴头的材质在检修中出现的问题。对包钢引进大方坯和大圆坯的汽雾喷嘴和国产喷嘴的冷态特性进行测试研究 ,测试结果表明 ,国产喷嘴的水流密度分布在中心的左右 ,分布均匀 ,对大方坯和大圆坯的横向均匀降温有益 ,但是国产喷嘴的喷射角度在测试的五种喷嘴中 ,有四种喷嘴符合国家黑色冶金对喷嘴喷射角度的要求 ,只有D40 197- 1喷嘴在高压测试时超国家要求的 +4° ,有少量国产喷嘴在同压力条件下的流量误差在 1%～ 10 %之间     

超低头板坯连铸二冷喷淋系统的优化

为进一步提高超低头铸机板坯质量,通过对目前连铸二冷区现有喷嘴的冷态特性进行测试分析,研究了喷嘴的特性及布置.从喷嘴选型、喷嘴布置及电动阀选型方面进行了优化设计,实现了“弱冷”配水的均匀冷却,使铸坯矫直温度横向、纵向都控制在980～1 020℃,提高了铸坯二次冷却的效果.     

旋涡柱精矿喷嘴冷态试验研究

介绍了关于旋涡柱精矿喷嘴冷态试验的模化设计,探索了该型喷嘴冷态试验条件下气相流场和微粒分布的特征,初步确定了旋涡柱精矿喷嘴的结构类型。     

连铸二冷喷淋喷嘴分布配置的研究

根据连铸坯的凝固传热规律,采用数学解析法,推导出二冷喷淋区某喷淋冷却段内的喷嘴分布配置方法,使喷淋冷却段内的喷淋水量分布与连铸坯的凝固传热特性相适应,以进一步改善铸坯质量。     

200 mm×200 mm方坯连铸机二冷区喷嘴冷态特性研究

通过对200 mm×200 mm方坯连铸机二冷区喷嘴进行测试,考察了目前在用的3/8PZ7050QZ5、HPZ2.0-60QZ2和HPZ1.5-60QZ2三种型号喷嘴的压力和流量特性、水流密度、打击力和喷射角等冷态性能参数。测试了不同水压条件下,喷嘴的喷射角、水流密度分布随水压变化的情况。测试结果表明:水喷嘴的喷射角随水压变化较小,各水压下的喷射宽度和水流密度可满足铸坯的冷却需要,但较小的水压易造成喷出水滴的粒度过大,不利于铸坯均匀冷却;气水喷嘴的喷射角随水压增大而递增,保持气压0.2 MPa不变,当水压达到0.2 MPa及以上时,喷射宽度大于铸坯宽度,水流密度分布曲线由中心逐渐向边部发散且偏离中心,喷出水滴的雾化程度逐渐加剧。     

360 mm×450 mm方坯连铸机二冷区喷嘴的冷却特性

采用二冷区喷嘴冷态性能测试实验装置对攀钢360 mm×450 mm方坯4流连铸机的9种扁平气水喷嘴特性进行了测试.测试表明,3/8PZ 10.6-120PG水喷嘴在喷嘴高度h为115 mm和140 mm,喷射角度为115.6°和115.1°时,喷射有效长度d分别为365 mm和440 mm.HPZ4.8-90PG气水喷嘴的喷射角度为106.7°,当气压为0.15～0.30 MPa、水压0.30 MPa时,h为210 mm,d为515～565 mm.     

喷嘴喷淋距离对连铸小方坯二冷均匀性的影响

研究了不同喷淋距离下连铸小方坯二冷喷嘴的水量分布,建立了凝固传热模型分析了82B钢连铸坯的热行为。该模型特别考虑了二冷区铸坯表面宽度方向的水流密度分布,并根据铸坯表面测温结果进行了模型校正。采用凝固传热模型研究了喷嘴喷淋距离对连铸二冷均匀性的影响。结果表明:喷嘴喷淋距离的增加有助于提高二冷水横向分布的均匀性,导致铸坯表面温度横向均匀性降低、纵向均匀性提高。这些效果有助于改善铸坯内部裂纹,但是会对角部裂纹产生不利影响。在二冷区前段喷嘴采用低喷淋距离,二冷区末段采用高喷淋距离,既可以提高铸坯角部温度,又能降低表面最大回温速率,有助于同时改善连铸坯角部和内部裂纹。在此基础上,提出了一种连铸小方坯二冷喷嘴布置方式,即二冷区每段喷嘴喷淋距离沿拉坯方向逐渐增加,该方法有助于提高连铸坯“纵?横”冷却均匀性。      

Modeling Water Distribution for Irrigation Machine with Small Spray Nozzles

A model and computer program were developed to calculate water application depth and uniformity coefficient for small spray nozzles mounted on a center-pivot irrigation system. The program requires two basic inputs. First, the experimental data for the static distribution pattern of the spray nozzle, including collection time, spacing between collection cups, cup opening radius, and volume of water collected in each cup at a specific pressure and height are required. Second, irrigation system inputs including spacing between spray nozzles, radius of distal end tower and moving velocity, distance of spray nozzle from the pivot, move stop cycle time, or cycle time, and percentage of moving time from the cycle time, or percentage of moving time are needed. The outputs are water application depth and uniformity coefficient. Experiments were conducted to validate the simulation for various moving velocities, spacing between spray nozzles, cycle times, and percentages of moving time. Results showed that the uniformity coefficient of water distribution was 98.4% of the predicted coefficient and that by changing cycle time, or percentage of moving time, the uniformity coefficient was improved by as much as 14.2%.     

Influence of running water on the heat transfer in continuous casting

The influence of running water on spray water cooling is experimentally looked at with the aid of a stationary working experimental plant. The running water was fed separately to the sample from above as a defined water film by using a slot nozzle. In addition to the spray nozzle pre-pressure, the velocity of the running water at the slot nozzle exit and the temperature of the running water, the angle of inclination of the sample plane was also varied. By employing three different full cone spray nozzles and setting different nozzle distances, a range of 450 to 2000 l/(m²·min) of the water impingement density was covered. To estimate the marginal influences, samples of 20 × 20 mm as well as 30 × 30 mm were used. Studies of initially pure spray water cooling without the additional running water film revealed a dependency of the heat transfer on the spray water impingement density, the spray water velocity and also the angle of inclination of the sample plane. For nozzles with a low water impingement density, a superimposing of a running water film on the spray water revealed a sharp increase in the heat transfer coefficients compared to pure spray water cooling. For nozzles with a high water impingement density and, therefore, with a high heat transfer already even for pure spray water cooling, the increase of the heat transfer coefficient is minor.     

An experimental study on the atomization characteristics of the nozzle for the after-pot cooling of galvanized steel sheets

Air-atomized fog cooling is particularly suitable for the after-pot cooling of galvanized steel strips.With air and water serving as working media,an experimental study was conducted on the atomization characteristics of a newly-developed cross-flow type of fog nozzles.The water flux distribution,spray angle and pressure of water and air were measured.The results show that the water droplet size was small and insensitive to the water flow rate.The spray angle was small and the water flow rate slightly affected the air pressure in the chamber.An empirical correlation between the pressure in the chamber and the gas flow rate was obtained for the purpose of equipment design.     

高效连铸二次冷却喷嘴的性能

对某小方坯连铸机高效化改造中，二次冷却区所采用的三种喷嘴的冷态及热态性能进行了研究，获得了相应的性能参数。还对高效连铸二次冷却对喷嘴性能的要求进行了评价，提出了有效喷淋系统的概念。     

喷雾转筒冷却机喷雾冷却性能

 喷雾转筒冷却机是转底炉生产线上的关键设备之一。为了提高冷却机的冷却性能,针对转筒外喷雾冷却系统换热特性,应用CFD数值模拟技术建立传热过程耦合模型,研究了喷嘴数量、间距以及偏移量等布置参数对换热的影响。结果表明,数量过多、间距过小或数量过少、间距过大均不利于传热,合适的数量和间距对设备冷却性能具有积极作用,喷嘴平行四边形排列在一定程度上优于矩形排列。最后通过具体工程应用试验验证了研究成果的正确性。     

150t转炉一次除尘效果及节能研究

150 t转炉一次除尘系统的喷嘴,喷水量比较大、供水压力低,而且喷嘴易堵塞,导致除尘有盲点,除尘效果不好,烟囱时常有冒黄烟、黑烟现象,对周围环境影响很大。另外,由于用水量较大,煤气洗涤的水泵常处在超负荷工作状态,耗能高,效率低。对此进行研究并采取了改进措施。     

Dust Suppression Using Truck-Mounted Water Spray System

The control of dust on construction sites is an issue of concern of many communities that experience a high level of construction activity. Dust suppression typically involves using large water trucks to spray haul roads, material stockpiles, and other areas being worked by equipment. This method of dust control leads to labor, operating, and safety costs and complications that can limit and sometimes prohibit its implementation. Other spray methods that are cost-effective, easy to implement, functionally viable, and safe are needed that provide direct and effective dust control for each piece of equipment. This paper describes a research project to develop and evaluate a water spray system for suppressing dust emissions that is attached directly to a piece of earthmoving equipment, specifically a dump truck. The system consists of distribution hose, pipe, and spray nozzles attached to the perimeter of the truck body, and a water pump and water tank secured to the truck's frame. The system's design takes into account various operational and performance factors, including water consumption rate, spray configuration, equipment function and operation, dust suppression effectiveness, and cost of installation and use. It is expected that the system developed can play an effective role in minimizing dust emissions from construction sites.     

分段式除鳞在热连轧上的应用

主要论述了某热轧厂精轧除鳞箱改造前状况及存在的主要问题;改造方案及改造后分段式除鳞的技术特 点。研究表明通过除鳞集管分段控制能够在保证除鳞效果的条件下降低该工序的能源介质消耗。改造实践证明 在除鳞系统压力不变的条件下,通过除鳞集管分段式控制,同时优化喷射角、入射角和喷射距离等射流参数以及合 理选择喷嘴型式等措施,能够提高除鳞打击力,改善除鳞效果,并有效降低除鳞能耗和除鳞水量。