唐纳森沙漠空气滤清器

目前,多数工程机械都装配有空气滤清器,以保护发动机。但若发动机常在沙漠、油田、煤矿等灰尘"重灾区"工作,普通空气滤清器就难以满足延长发动机使用寿命的要求。为此,唐纳森于近期推出了一款沙漠空气滤清器。沙漠空气滤清器是由多旋流管式预过滤器和纸质滤芯组成的双级干式空滤器,适用重型汽车及工程机械。气体从进气口进入旋流管进行预过滤,大部分灰尘受离心作用被滤出,并通过锥形管道导入储灰盘。预过滤后的气体再经过旋流管内管进入主滤芯,得到进一步过滤。因旋流管的预过滤效率高达90%以上,能有效减少进入滤纸一侧的灰尘     

推土机用空气滤清器的选型与应用

空气滤清器是推土机发动机进气系统的主要部件之一,主要作用是滤除空气中的有害杂质颗粒,保证进入发动机气缸的空气质量,最大限度地降低发动机磨损并保持最佳的发动机性能。介绍空气滤清器的作用及分类,干式空气滤清器的性能指标及选取,各种类型惯性式预滤器原理及性能比较。以案例形式介绍某型推土机进气系统设计、选型过程,以及空气滤清器安装及管路连接设计注意事项。     

几种常见装载机发动机空气滤清器的应用

以装载机的使用工况为基础,介绍常规型空气滤清器、油浴式空气预滤器、旋流管式空气滤清器和串联式空气滤清器等4种常用的不同发动机空气滤清器的特点和使用工况,并列举两个空气滤清器的实际选用案例,为主机设计者以及用户提供发动机进气系统设计以及改装的参考。     

高效多级空气滤清器

介绍一种适用于在恶劣环境下工作的工程机械用高效多级空气滤清器。该滤清器由两级粗过滤器和一级精滤器集合而成，并带有废气引射抽尘装置。这种高效空滤器过滤能力强，总成滤清效率可达99．7％以上，具有使用寿命长，保养方便、结构紧凑等特点。     

挖掘机用干式空气滤清器的维护保养方法

空气滤清器对于发动机的使用性能和寿命都有很大的影响,做好空气滤清器的日常维护保养,不仅可以有效防止发动机的异常磨损,而且还可以有效地延长发动机和空气滤清器的使用寿命。对空气滤清器的分类和结构进行简单的介绍,对挖掘机用干式空气滤清器的清理频率、清理方法,以及正确的更换和安装方法进行阐述,分析可能存在的保养误区及因此而产生的危害,并提出正确有效的维护保养方法。     

工程机械设备高位进气装置设计及分析

在公路、机场、堤坝、铁路等工程建设中所使用的大量工程机械设备,经常处于灰尘扬起的环境,因此,在工程机械设备周围的空气中含有大量灰尘,这些灰尘将严重影响施工设备的使用寿命.发动机的进气方式对于设备的使用至关重要,在动力系统设计时应重点关注进气方式.高位进气系统方案,可以使空气滤清器吸收到清新、干净的空气,延长空气滤清器的保养操作间隔时间,降低维护保养的劳动强度,延长空气滤清器的使用寿命,进而延长机器设备的使用寿命,降低用户的使用成本.     

如何正确保养干式空气滤清器

干式空气滤清器在使用一段时间后，滤芯会变脏，滤清器的进气阻力也会随之增大，严重时会导致发动机出现排黑烟、动力不足等现象。操作人员在保养干式空气滤清器时存在一些认识上的误区，如对空滤器滤芯的清理间隔选择比较随意，并认为越勤越好；清理滤芯的空气压力过大，认为这样容易清理干净；将主滤芯和安全滤芯一同清理等。提出正确清理空气滤清器滤芯的方法以及使用中的注意事项。     

摩托车空气滤清器浅析

本文结合我厂产品开发，简叙了空气滤清器设计情况，正确处理降低进气阻力，进气噪音，提高滤清效率和储尘能力的关系，增加空气滤清总容积，加大滤气面积及选择适当的滤清材料是改善发动机性能，提高空气滤清器工作质量的有效放途径，同时提出了空气滤清器设计中应注意的几个问题。     

摩托车空滤器的气阻测试

本文介绍了摩托车空气滤清器气阻测试设备的结构，分析了在测试过程中，空气流量，大气状态等地气阻值测试结果的影响，并提出了测量和评价空滤器气阻性的方法。     

建筑机械空气滤清器的选择与使用

空气滤清器的作用是滤除空气中的灰尘,以减少气缸壁、活塞环、气门等零件的磨损,延长发动机的使用寿命。建筑机械由于经常在含尘量高的恶劣条件下工作,因此,对空气滤清器的选择与使用提出了更高的要求。据有关资料介绍,在发动机发生早期磨损情况下,75%是由灰尘引起的。来自用户的信息反馈,也主要反映空气滤清器选择或使用不当而使发动机出现故障,直至造成主机的长期停机。为此,空气滤清器的     

Contaminant particles removal by negative air ionic cleaner in industrial minienvironment for IC manufacturing processes

This study was carried out in a closed test chamber under natural decay, negative ionic air cleaner application, as well as air mixing mechanism with negative ionic air cleaner. Among three operation modes, the air mixing mechanism with negative ionic air cleaner can reduce particles better under the flow field condition. In the air mixing, especially vigorous one (5 ACH (Air Changes per hour)), enhanced the air cleaning effect. The highest removal efficiency was measured at a height of 0.6 m from the floor and it was decreased substantially with an increase in height. The relative effectiveness of negative ionic air cleaners was predicted to decrease with an increasing particle size. We also found that there was a limited horizontal diffusion of ions. The empirical curves fit based for the concentration gradient of NAI (Negative air ionization) generated was developed for estimating the NAI concentration with different heights and distances from the source of negative ionic air cleaner discharge.     

Flow impact of an air conditioner to portable air cleaning

In order to reduce indoor pollutant exposure, people become increasingly interested in portable air cleaning devices, which can be positioned with flexibility. Such purification devices usually discharge cleaned air with strong momentum, which can interrupt indoor airflow created by air-conditioning units. If a well-organized air circulation to a portable air cleaner is not achieved, indoor air purification cannot be fully ensured. This study has used both measurement and computational fluid dynamics (CFD) modeling to investigate the flow interaction between an air conditioner and a portable air cleaner to purify indoor gaseous pollutants. A workshop environment conditioned by an air conditioner and cleaned by a portable air cleaner was mimicked in an environmental chamber to obtain data for validation of a CFD program. Then CFD was applied to evaluate factors that may affect air purification including: positioning of the air conditioner and air cleaner, air conditioner diffuser types, air-conditioning cooling or heating running mode, and location of pollutant sources. The study finds the simulation results are in good agreement with the corresponding experimental data. The positioning coordination of an air conditioner and an air cleaner, and selection of air conditioner diffuser types shall assure a good air circulation cycle to the air cleaner to improve air purification efficacy. In addition to the cleaner effectiveness, it is also recommended to evaluate an air cleaning device in terms of the absolute pollutant concentration, if the portable air cleaner is under the interaction of an air conditioner and the local performance data are interested.     

Numerical analysis for evaluating the “Exposure Reduction Effectiveness” of room air cleaners

An “Exposure Reduction Effectiveness” index is proposed to quantify the performance of room air cleaners based on their capability of reducing occupants' exposure to pollutants of interest. The index has advantages over existing index such as CADR. It is applicable to both room average and local breathing zones, and can be used to compare air cleaning with the other two IAQ strategies: ventilation and source reduction. A computational fluid dynamics model is developed and used to assess the effectiveness of a room air cleaner for VOCs and particles of different sizes. The simulation results show: (1) species transport model and drift-flux Eulerian model can be used to predict concentration distributions of gaseous pollutants and particulate matters when there's an air cleaner operating and CFD simulation is an efficient tool to analyze personal ventilation; (2) the Exposure Reduction Effectiveness (ERE) index is effective for describing the removal effectiveness of room air cleaners in local zones as well as the room average.     

Fractional Aerosol Filtration Efficiency of In-Duct Ventilation Air Cleaners

The filtration efficiency of ventilation air cleaners is highly particle-size dependent over the 0.01 to 3 μm diameter size range. Current standardized test methods, which determine only overall efficiencies for ambient aerosol or other test aerosols, provide data of limited utility. Because particles in this range are respirable and can remain airborne for prolonged time periods, measurement of air cleaner fractional efficiency is required for application to indoor air quality issues. The objectives of this work have been to 1) develop a test apparatus and procedure to quantify the fractional filtration efficiency of air cleaners over the 0.01 to 3 μm diameter size range and 2) quantify the fractional efficiency of several induct air cleaners typical of those used in residential and office ventilation systems. Results show that efficiency is highly dependent on particle size, flow rate, and dust load present on the air cleaner. A minimum in efficiency was often observed in the 0.1 to 0.5 μm diameter size range. The presence of a dust load frequently increased an air cleaner's efficiency; however, some air cleaners showed little change or a decrease in efficiency with dust loading. The common furnace filter had fractional efficiency values of less than 10% over much of the measurement size range.     

Impact of placement of portable air cleaning devices in multizone residential environments

An advantage of portable air cleaners is that they can be positioned in different parts of a building and used where air cleaning is needed. This makes them a popular choice for use in residential buildings. In typical indoor particle modeling efforts, perfect air mixing and uniform contaminant concentration distribution are assumed. However, nonuniform spatial concentrations of particles are more reflective of most environments. Using experiments to validate computational fluid dynamic and particle tracking models and applying these models in numerical based parametric analysis, this paper analyzes the overall contaminant removal in a multi-room residential building. Simulations varied (1) particle size (0.74, 3.4 and 10 μm), (2) clean air delivery rate (CADR) of the air cleaner (50 m³/h and 500 m³/h), and (3) position of portable air cleaner in different rooms. The results show very large variation of the overall particle removal for different positions of portable cleaning device. In extreme cases, the effective positioning of cleaning device can result in a factor of 2.5 change in overall particle removal and, consequently, strongly affect occupant exposure to particles.     

Method for Evaluating Efficiency in Removing Perceived Air Pollutants by Air Cleaners

The results of subjective experiments to evaluate the efficiency of portable air cleaners for perceived air pollutants generated by tobacco smoke are described. The efficiency of the five types of air cleaners to remove perceived air pollutants was evaluated by a panel using the decipol unit, and the efficiency to remove particulate was evaluated from concentrations of particulate. It was found that the efficiency of the air cleaner in removing perceived air pollutants was quite different from that in removing particulate     

Particle transport characteristics in indoor environment with an air cleaner: The effect of nonuniform particle distributions

Air cleaners are expected to improve the indoor air quality by removing the gaseous contaminants and fine particles. In our former work, the effects of the air cleaner on removing the uniformly distributed particles were numerically investigated. Based on those results, this work further explores the performances of the air cleaner in the reduction of two nonuniform particle distributions generated by smoking and coughing. The Lagrangian discrete trajectory model combined with the Eulerian fluid method is employed to simulate the airflow pattern and particle transport in a room. In general, the results show that the particle fates have been resulted from the interaction between the emitting source and the air cleaner. And the position of the air cleaner is a key parameter affecting the particle concentration, for which a shorter distance between the air cleaner and the human body corresponds to a lower concentration. Besides, the air velocity emitted from the human mouth and the orientation of the air cleaner can also influence the transport of particles.     

Characterizing gaseous air cleaner performance in the field

As part of an ongoing effort to better understand the performance of indoor air cleaners in buildings, the National Institute of Standards and Technology (NIST) has completed a series of gaseous air cleaner field tests and model simulations. This paper focuses on experiments to measure the removal of decane with a sorption-based in-duct gaseous air cleaner and a sorption-based portable air cleaner in a single-zone test house. Due to the lack of standardized gaseous air cleaner field testing protocols, a field test method was developed using semi-real-time concentration measurements and mass balance analysis. A total of 24 experiments were completed with directly measured single-pass removal efficiencies ranging from 24% to 56% and removal efficiencies based on a transient whole building mass balance ranging from 30% to 44%. Experimental results revealed important factors affecting field performance such as air cleaner contaminant loading for the in-duct air cleaner and room air mixing for the portable air cleaner. An additional six tests were conducted to evaluate the predictive capability of the indoor air quality model CONTAM.     

The contaminant removal efficiency of an air cleaner using the adsorption/desorption effect

The adsorption and desorption of volatile organic compounds (VOCs) in relation to material surfaces were conducted to control indoor air quality. The VOC removal performance of building materials using sorption effects was validated in cases related to poor indoor air quality that occurred during non-ventilation periods during intermittent-ventilation situations. The objective of this investigation is to present the contaminant removal efficiency and practicality of a prototype air cleaner which uses sorption effects. Toluene and formaldehyde were used as pollutant sources and were continuously emitted into the test chamber. Effects due to the number of sorption units, operation time and mode of contaminant removal performance were examined. The sorption materials evaluated in this investigation were a porous material, zeolite, pumice stone and hydro-corn. As a result of the experiments, zeolite exhibited relatively high contaminant removal efficiency with toluene, and zeolite and the porous material exhibited high removal efficiency with formaldehyde for both one-cycle and two-cycle sorption modes. Moreover, significant removal performances were observed in the numerical analysis of the continuous-operation mode.