高层住宅楼地下水泵房进水系统噪声的治理

本文阐述了高层住宅楼地下水泵房水池进水过程中噪声产生的机理和传播影响途径 ,并通过三个工程实例简要介绍了地下水泵房进水系统噪声的治理方法和效果。     

进水泵房自控系统说明

净水厂进水泵房的作用是为水厂一二期和三期以及水厂绿化提供水源,本文从进水泵房的控制模式、流量调节、压力调节、水泵的停机保护、水泵的自动启泵控制及自动停泵控制等方面进行了介绍,综述了进水泵房在各个方面的控制特点。     

大庆油田注水站噪声与振动综合治理技术研究

为降低油田注水泵房的高噪声,减轻噪声对一线员工的污染。针对大庆油田采油六厂喇十三注水站注水泵房,采用吸声、隔声、隔振等技术措施,利用Raynoise软件对注水泵房治理前后的声场分布进行了模拟,通过模拟结果确定了最经济的噪声治理方案,系统地介绍了油田注水站综合降噪技术与应用经验。     

南京友谊服装厂真空泵房噪声控制

一、概况 南京友谊服装厂的真空泵房安装了从日本引进的整套熨烫设备的动力源:真空泵两台(型号:HG20,电机型号RPM,功率15kW);空气压缩机一台(20m~3/h,电机5.5kW)和水泵三台(型号:DAi-50×6,转速2950r/min,轴功率14.5kW,配用功率5.5kW)。泵房面积约80m~2,房间空间低矮狭小,末作吸声处理,混响声很强。 泵房内噪声主要由真空泵和空压机的机械噪声和空气噪声所组成。另外,进、出气口的引管又散发出大量的热量,夏天泵房内温度高达50℃左右。在通常情况下,泵房内一台真     

陡河发电厂高压泵房噪声治理

陡河发电厂高压泵房内各类设备在工作时产生强烈噪声。本文对该泵房噪声污染情况进行了测量分析,并对其中溢流泵和轴封泵驱动电机等主要声源采取加装消声器的方法进行了噪声控制,使泵房内噪声污染状况得到改善。文中详细介绍了各类消声器的设计方法和结构特点,并给出了治理前后噪声测量结果。     

高压水泵的噪声治理

一、概述 天津人民农药厂新建的泵房,噪声高达104dB(A),机房外5m处的噪声高达90dB(A)以上,直接影响值班人员的身心健康和周围的环境。为此,我厂接受委托对其进行了治理。 泵房为钢筋混凝土建筑,长宽高分别为10×5×3.5m。内装两台6S6单级双吸式水泵,所配电机为J02-91-2,功率为55kW,转速为2950r/min,经测定泵房噪声为104dB(A),其频谱如图1所示。     

一种圆筒状污水泵站降噪工程设计

一种圆筒状结构城市污水泵站设备运行噪声高达90dB(A),对临近居民楼产生噪声污染。对圆筒状建筑结构特点与声源进行了分析,确定水泵运行噪声与室内混响噪声影响较大,采取了室内吸声与设备隔振等综合性降噪措施。通过吸声降噪与隔振设计,确定了泵房降噪工程方案与材料参数,并与现场试验测试数据进行了对比分析。结果表明,泵房室内工作台位置降噪量达17.6 dB(A),水泵1米处降噪量达6.8dB(A),厂界噪声满足1类声环境功能区噪声限值要求,获得了预期工程效果。     

建筑室内给排水管道噪声的分析与控制

分析了建筑室内给水排水管道噪声产生与传播的原因,探讨了控制建筑室内给排水管道噪声的相应措施。从设计和施工两方面出发,论述了给排水管道的布置、给排水管材的选用及给水泵房的减振隔声等内容     

水下钻孔爆破减震安全技术及应用

介绍了广西贵港电厂取水泵房进水前池基岩水下钻孔爆破技术方案。该方案采用微差爆破技术,段间时间间隔≥50 ms,炮孔直径100 mm,孔距1.5m;排距1.2 m,平均孔深3 m,炸药单耗1.2 kg/m3,并在距水泵房前沿8 m处布设2排预裂减震孔,孔径110 mm,孔距0.5 m,排距1.2 m,孔深7 m。为了降低爆破引起的水冲击波对取水泵房的影响,还在取水泵房前沿5 m外设置1道水下空气帷幕。爆破施工实践表明,该方案有效降低了水下爆破对相距不足10 m的近距离取水泵房的振动影响,保障了取水泵房的安全。     

水源出口泵房机组技术改造方案

为解决沈阳浑南水务集团二水厂出口泵房在地表水置换地下水后,泵房机组夜间用水低峰时水泵效率低能耗高的问题,根据水泵运行工况,结合管网用户所需要的流量、扬程,选择相匹配的水泵机组,与原有的水泵机组形成阶梯供水的组合。通过实施水泵机组改造,使低峰时段的机组效率大幅度提高,从而避免大功率水泵长时间低效运行,达到降低能耗的目的。     

Estimation of Parameters of Universal Distribution of Moments of Failure of Products

A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling.     

Evaluation of optical properties of highly scattering media by moments of distributions of times of flight of photons

A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue.     

Assessment of intakes of mixtures of radionuclides

Australia has several uranium mines and a large number of mineral sand mines, with associated processing facilities. Exposures resulting from these mining and processing operations usually involve intakes of mixtures of radionuclides. This work describes the development of a suite of first order, linear compartment models, based on the ICRP Publication 66 respiratory tract model, and an analytical solution to the decay equations, for assessing the consequences of such intakes. The computer programs based on these models directly compute excretion, organ retention and organ and whole-body doses for intakes of either single radionuclides or any mixture of radionuclides belonging to the same radioactive decay chain. The intake can be via inhalation, ingestion or injection, and can be acute, chronic or of limited duration. The starting concentration and degree of secular (dis)equilibrium can be specified for each radionuclide. No assumptions need to be made about the relative magnitudes of the radioactive half-lives of the different nuclides.     

Estimation of potentialities of methods of summation of direct measurement errors

Conventional methods for summation of direct measurement errors are considered. Conditions under which these methods provide consistent results are stated. It is proposed to utilize for characteristic of the total error, its interval estimator or the half-sum of the value obtained by adding up its arithmetic and geometric random errors.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 10–12, April, 1995.     

卧式金属罐容量的测量结果不确定度

本文根据多年的实践检定经验 ,参照JJF1 0 59- 1 999《测量不确定度评定与表示》以及《测量不确定度表达 1 0讲》 ,对卧式金属罐容量的测量结果不确定度进行了评定。     

盐酸浓度不确定度的评估

通过对盐酸浓度标定的过程分析，找出影响结果的各个分量，进行不确定度的评定，按照计量技术规范给出标准的表示法。     

空压机轴承箱蜗壳温度探头油封改造

由于空压机进气侧轴承箱蜗壳温度探头密封效果不好,使空压机及其后续管道受到油污染。后将温度探头的O形圈密封改为骨架油封,杜绝了轴承箱漏油问题。文章简介空压机的结构和技术参数,详细介绍了骨架油封的制作和优点。