中央空调系统噪声测评与控制对策

由于中央空调设计缺陷,安装时没有采取有效的减振措施引起机壳振动或管道风量调节不当,导致噪声超标,引发了许多经济纠纷。只有通过对空调系统噪声进行正确测试与合理评价,找出噪声超标的原因,才能化解这方面的矛盾。     

杭州市农贸市场的噪声特点分析

对农贸市场噪声进行了监测分析。结果发现,农贸市场营业时,市场内的噪声超标,其最小值出现在中午,最大值出现在下午下班高峰期;农贸市场一天内不同时段噪声污染级的数值大小有一定的差距;用噪声冲击指数来评定农贸市场声环境质量,其声环境质量极差。     

建筑施工噪声的监管与控制

在城市化进程加快的过程中,建筑施工产生的噪声如果不加以监管和防治,势必污染环境,影响居民的正常生活、工作与学习。建筑施工单位自身应使用低噪声的设备,改进施工方法,采取隔声、减噪等行之有效的措施,防治噪声污染,环保部门也要对其加强监管与指导,对违法施工、噪声超标排放的行为进行查处,以维护居民的合法权益不受侵害。     

医院和旅馆的噪声管理

防治噪声污染是为了创造一个安宁、适宜的生活和劳动环境。噪声污染涉及的领域很广,应从各个方面加以控制。然而,由于噪声污染不同于水、气、渣污染,除特强噪声外,一般不会造成致命性危害。就现阶段而言,噪声管理的重点是保护居民的睡眠环境,环保部门按国家标准和地方法规,对污染者征收超标排污费,并限期治理。这方面已经收到明显的环境效益,得到了居民的赞赏。但是,城市中有一类极为重要的睡眠休息环境被遗忘了,这就是医院(包括疗养院)病房和旅馆(包括招待所、饭店、宾馆)客房。     

两例振动和噪声污染源的识别

通过两例噪声和振动污染相互转换的事例分析，阐述了同一种介质中振动和噪声是一对扯不开的连体孪生兄弟。在不同介质之间，振动和噪声可能发生相互转换，在一定的条件下，固体的振动会激发产生空气中的噪声，空气中的噪声也会导致固体产生振动。     

从一起噪声扰民的民事案件谈居民的空调噪声标准

从一起邻里间空调噪声扰民的民事案件，阐述了居民邻里间空调扰民噪声监测方法及执行标准，从实践体会到，国家应制定更合适的噪声标准和测量方法，以利于处理这类问题。     

一起噪声扰民监测案例的思考

通过一起噪声扰民监测案例，叙述了《工业企业厂界噪声》和《建筑施工场界噪声》的内涵与特征，针对特定的噪声污染现状，提出更加合理的监测方案，有助于解决噪声扰民的信访案件。     

室内箱式变压器结构声污染及对策

通过对置于住宅楼底层室内箱式变压器引起的结构声污染进行调查实测，在对箱式变压器结构声传播进行声学分析基础上，提出了切实可行的防治对策，经实际工程应用验证，效果较好。对机房正上方住房主卧内降噪量为5.0dB，室内夜间噪声降为30.2dB，各层住户夜间烦恼度普遍从非常烦恼或烦恼降为有点烦恼和不大烦恼。这从噪声污染控制的角度证明了变配电房置于住宅楼等噪声敏感建筑物室内底层甚至更高楼层在技术上是可行性的。同时也为杭州市正在试点推广的箱式变压器置于噪声敏感建筑物底层提供了实践依据。     

从苏州航道噪声的变化谈其治理

从苏州20多年对护城河航道噪声的监测，通过数据处理和变化趋势分析，谈其航道噪声治理及对策。     

对铁路两侧过渡带区域噪声环境标准的研究

选择主要铁路干线经过的具有代表性的大中型城市，通过大量的铁路噪声监测数据的统计分析和理论计算，研究铁路噪声特点及其传播过程中的衰减规律；确定铁路两侧过渡带区域范围，提出过渡带区域噪声环境标准，指导环保部门对铁路两侧区域的环境管理和功能区的合理设置。     

工业用制氧机噪声控制方案

在大型炼钢生产工艺过程中,需要制备大量的氧气.由于空气流量大,制氧机进口噪声大,对周围环境和工作人员造成了极大的危害.对某钢铁集团制氧机的噪声源进行了分析,并在现场调查的基础上,提出了制氧机噪声治理方案.经过测试,治理后的厂界噪声指标达到国家标准的控制要求.     

卡拉OK扰民噪声治理的研究

分析了卡拉OK扰民噪声的特点 ,通过现场实验和实测 ,研究了不同装修结构对房间隔声、隔振效果的影响     

室外大型空气压缩机的噪声治理技术

某室外安装的大型空气压缩机对环境造成了严重噪声污染,离机器2m远处噪声高达114 5dB(A)。在不允许停机的情况下,充分利用现场条件,采取了为空气压缩机加隔声罩、进气口滤清器加消声百页和管道作隔声包扎等综合治理措施,相应测点噪声已降至88 7dB(A),厂界噪声降至机器安装前背景值。室外机器的噪声控制方法与室内机器有许多不同,分析了这些差异并重点介绍了所设计的隔声罩在声学、通风、耐气候性和结构等方面的设计要点。     

用空气弹簧降低变压器结构噪声的工程实践

绿岛华庭变压器安装于居民住宅楼一层,其运行噪声长期对楼上居民产生干扰。文中详细分析了变压器产生结构噪声的机理,介绍了一种自适应装置的空气弹簧减振器,用该减振器对变压器结构噪声进行了卓有成效的治理。     

Utilization of Air Cleaning Equipment In Exhaust Air Recirculation Systems

The energy crisis is providing an incentive for industry in the U. S. to conserve fuel. A major consideration is the recirculation of Industrial exhaust air to reduce energy consumption in heating or cooling work place air. Although there is a history of literature on the subject, design criteria for recirculation systems are very limited. Primary system components are air cleaning equipment and monitoring/alarm equipment. If feasibility of recirculation is established, air cleaning equipment must be selected to remove specific contaminants properly. Types of air cleaning equipment are reviewed from the standpoint of collection mechanism, equipment configuration, performance capability, and applicability to recirculation. Monitoring equipment requires significant development work to assist in safeguarding re-circulation systems and to provide worker protection.     

Measurements of carbonyls in a 13-story building

BACKGROUND, AIM AND SCOPE: Formaldehyde and acetaldehyde are emitted by many mobile and stationary sources and secondary aldehydes are intermediates in the photo-oxidation of organic compounds in the atmosphere. These aldehydes are emitted indoors by many materials such as furniture, carpets, heating and cooling systems, an by smoking. Carbonyls, mainly formaldehyde and acetaldehyde, have been studied because of their adverse health effects. In addition, formaldehyde is a suspected carcinogen. Therefore, the concentrations of formaldehyde and acetaldehyde were determined to assess the inhalation exposure doses to carbonyls for people who work in a 13-story building and in order to evaluate the cancer hazard. METHODS: Carbonyl compounds in indoor and outdoor air were measured at a 13-story building located in Mexico City. The mezzanine, fifth and tenth floors, and the third level-parking garage were selected for sampling. Samples were collected in two sampling periods, the first from April 20 to 29, 1998 and the second from December 1 to 20, 1998. Carbonyls were sampled by means of DNHP-coated cartridges at a flow rate of 1 l min(-1) from 9:00 to 19:00 hours, during 2-hour time intervals and analyzed by HPLC with hours, during 2-hour time intervals and analyzed by HPLC with UV/VIS detection. RESULTS: Mean carbonyl concentrations were highest in the 3rd level-parking garage, with the formaldehyde concentration being the highest ranging from 108 to 418 microg m(-3). In working areas, the highest carbonyl arithmetic mean concentrations (AM) were observed on the 5th floor. Acetone and formaldehyde concentrations were highest in April ranging from 161 to 348 microg m(-3) (AM = 226) and from 157 to 270 microg m(-3) (AM = 221), respectively. Propionaldehyde and butyraldehyde were present in smaller concentrations ranging from 2 to 25 and 1 to 28 microg m(-3), respectively, considering all the samples. Mean indoor/outdoor ratios of carbonyls ranged from 1.8 to 9.6. A reduction of inhalation exposure doses of 41% and 45% was observed in the fifth floor air after the air conditioning systems had been repaired. Formaldehyde and acetaldehyde concentrations were higher in smoking environments. CONCLUSION: Indoor carbonyl concentrations were significantly greater than outdoor concentrations. Tobacco smoke seems to be the main indoor source of formaldehyde. After the air conditioning system was maintained and repaired (as was recommended), an important reduction in the emission of formaldehyde and acetaldehyde was achieved on all floors, except for the 3rd level parking garage, thereby reducing the inhalation exposure doses. RECOMMENDATION: The results obtained in this research demonstrated that maintenance of air conditioning systems must be carried out regularly in order to avoid possible adverse effects on health. Additionally, it is mandatory that isolated smoking areas, with air extraction systems, be installed in every public building.