便携式气体微小流量校准装置研制

文章介绍了一种便携式气体微小流量校准装置,该装置为现场气体流量校准设计,在保证准确度的同时注重便携性,以层流流量计为标准表,采用质量流量控制器来自动调节流量点,双重减压阀和稳压阀来保证气源压力稳定。     

环道式高压气体流量装置储气系统研究

环道式高压气体流量装置是检测高压气体流量计的重要标准。本文介绍了环道式高压气体流量装置核心部件储气系统的原理和组成,并对环道式高压气体流量装置储气系统进行参数设计,通过理论分析,结构设计及储气容积、工作压力计算、压缩机选型,为合理化设计提供依据。     

化工部光明化工研究所特气管阀配套系列产品简介

该所除生产上列产品外,还小批量生产计量阀、流量限制阀、流量控制器、压力控制器、波纹管微调阀及各种气体纯化装置等,也可根据用户要求设计制造特殊的管阀件,以满足用户需要。     

热式气体质量流量传感器的工作原理及其应用

<正>一、前言热式气体质量流量传感器是气体质量流量控制器中一个重要的核心部件,对气体质量流量控制器的性能指标,如零漂、准确度、线性、重复度、响应时间等重要指标参数有直接影响。要使气体质量流量控制器的性能指标得到明显改善,首先就要提升热式气体质量流量传感器的性能。然而,热式气体质量流量传感器的性能与其本身的结构参数设计是密切相关的。如     

气体质量流量控制器的原理和应用

气体质量流量控制器的原理和应用质量流量控制器用于对各种气体的质量流量进行精密测量和控制，大量用于电子工艺设备（如扩散、氧化、外延、ＣＶＤ、等离子刻蚀、溅射等）以及镀膜设备、光导纤维制造中；并广泛用于石油化工、冶金、制药等行业。质量流量控制器的英文名字...     

气体小流量系统现场校准的可行性方案论证

介绍了气体小流量系统现场校验的基本组成部分,及为克服现场校准流量源不稳定所设计的恒流量装置,从而保证了现场校验结果的准确性,实现了气体小流量系统的现场校准。     

磁控反应溅射镀膜设备充气系统设计的几个问题

本文简要地讨论了磁控反应溅设备充气流均匀性的设计原理，质量流量控制器的选用原则和工作压力的控制方法。     

气体混合配比仪校准方法研究

阐述了气体混合配比仪的结构及工作原理,分别对其流量、压力以及密封性各计量参数指标进行研究。介绍了一种气体混合配比仪的校准方法,分别对气体流量、压力及密封性进行校准,实现整机多参数校准。     

用于气体流量控制的压电陶瓷阀的温度特性

采用PEV-1型压电陶瓷阀作为溅射气体Ar流量输出的驱动元件,用于真空磁控溅射镀膜中溅射气体恒压力控制.应用过程中发现压电陶瓷阀本身的迟滞特性和温度特性对气体输出流量有较大影响.试验分析得到压电陶瓷阀偏振电压变化过程中,气体输出流量的迟滞曲线.当压电陶瓷阀环境温度升高时,该迟滞特性会减弱,气体输出流量随偏振电压变化速率变大.     

气体质量流量计修正模块设计

文章针对工业中气体质量流量计校准装置结构复杂、操作不便、校准周期长和费用高昂等缺点,设计了一款气体质量流量计修正模块。该模块通过采集流量变送器输出的模拟量信号,获取被检表的流量值,然后再由屏幕控制器输入标准流量计测得的流量数值,经线性分段插值的算法进行参数校准,完成对被检流量计的流量校准。文章从软硬件设计层面上,介绍了该模块的整体设计和修正原理,经测试此修正模块能有效改善被检流量计的测量误差,在节约成本的同时提高流量计校准服务的效率。     

大气采样器稳流技术的设计

介绍了应用可编程逻辑控制器（PLC）和差压传感器构建稳流采样系统实现大气采样器采样流量恒定的设计原理和应用。     

Prüflecks für Schnüffel‐Lecksucher

In the testing of leak tightness and in the localisation of leaks by means of a test gas, proper operation and sensitivity of the employed instrument must be checked by a certified reference leak. In the so‐called sniffer mode of operation, the component under test is filled to overpressure with the test gas, so that in case of a leak there is a gas flow from the component to atmosphere. The atmospheric gas is sucked by the instrument and probed for its test gas content. For checking the instruments performance, commercial test leaks are available for various gas species, which deliver a well‐defined leakage. Construction and properties of such a test leak are described. The leak has an internal gas reservoir and a capillary as leak element. Because the inlet pressure at the capillary is kept constant by a pressure controller, the leakage remains constant over several years despite the gradual pressure decrease in the gas reservoir. The calibration of the leakage via the volume flow rate is described in detail. The volume flow rate can be measured by a liquid drop in a measuring capillary as well as a displacement piston in a dosing syringe.     

单螺杆式冷水机组中油压差控制器监控设计探讨

介绍单螺杆式冷水机组中油压差控制器的作用,以及油压差控制器在机组回油系统中的设计,并通过实例对设计方案进行分析比较,排除油压差控制器频繁报警现象,总结油压差控制器在系统设计过程中应注意事项。     

跨临界CO2引射制冷系统控制性能研究

本文建立了两种控制器（单通道最优控制器（SCOC）和多变量线性二次高斯控制器（LQG））以改善跨临界CO2引射制冷系统的运行效率。首先建立了SCOC,通过在线调节喷嘴喉部面积,搜索系统最优的气冷器压力;其次针对SCOC作用下制冷量不可控的缺点,设计了LQG以实现系统制冷量可调。将两种控制器分别应用于实验系统中,结果表明：SCOC能够驱使系统不断接近给系统的最优气冷器压力,给定工况下获得最大制热系数COPh为3.15,但导致系统制冷量的不可控。在LQG的作用下,气冷器压力、系统制冷量得到独立控制,显示了很好的参数跟随性,然而LQG无法保证系统的稳态运行效率。研究指出两种控制器各有优缺点,若实现满足系统负荷需求的同时保持系统最高的运行效率,需要设计结合两种算法特点的新型控制器。     

基于分子流传感元件的真空腔体漏率测量方法

本文介绍了一种基于分子流传感元件的真空腔体漏率测量方法,该方法通过分子流传感元件测量真空腔体整体漏率,采用的测量装置由气体流量测量系统、真空抽气系统、恒温系统等部分组成.在测量系统中,流经传感元件的气流处于分子流状态,通过测量传感元件两端的差压,计算质量流量,可以得到真空腔体的整体漏率.实验中对多个真空腔体漏率的测量结...     

车载LNG气瓶绝热性能便携式测试方法研究

基于车载LNG气瓶结构原理、现有检测方法和经济成本,采用定压方法进行了LNG气瓶绝热性能快速测试的实验研究。结果表明,在气瓶运行压力下,采用层流式质量流量计和压力控制器通过特定算法可以有效地反映气瓶的绝热性能,显著提高检测效率。     

Fragen zu Vakuum‐Molekularpumpen

Questions about vacuum molecular pumps For experiments about gas friction we used a turbomolecular pump with magnetic bearings. The blade system was replaced by a cylinder of carbon fiber materal. lt rotates in a stationary aluminium cylinder at a distance of 0. 8 and 0. 4 millimeters at a rotating speed up to 48000 rpm. We got a linear dependance of the reciprocal values of pressure and viscosity in good agreement with other experiments in that field. Preparing experiments showed us our apparatus is working like a pump too. We saw differential pressures in dependance of flow and gas pressures. In our sytem pumping works against the flow resistance. The pumping range is limited by a graph showing the compensation of pumping and resistance. Here we have no flow through the system but only in tangential direction by the rotation The experiments showed graphs with 2 arms showing the compensaion of pumping and flow resistance. In the range between the arms the pressure difference reaches the highbest negativ numbers. That is the point of best pumping. The position of this point decreases to lower rotation frequencies with rising gas pressure and flow. The question is: what are the reasons for this behavior? Possibly the molecular pump developped by Siegbahn uses this effect. It makes higher compression rates by lowering the friction speed. The molecular pump of the Holweck type has at a constant rotation speed an optimal pumping effect at a certain nitrogen gas pressure and flow. At this optimum the pump makes high compression rates for additional hydrogen or helium.     

用内文丘里管流量计测量酸气流量

介绍了新型差压装置--内文丘里管的结构、测量原理、技术性能;根据差压式流量计的测量原理,建立了计算酸气流量的数学模型,并将内文丘里管流量计成功地应用于酸气流量的测量.     

Druckregelung in Vakuumsystemen

In reactive processes a process gas is fed into the process chamber after evacuation. The most important precondition for a reproceable process is a stable process pressure. Pressure control is carried out either by controlling the gas flow on the gas inlet side or by regulating the effective pumping speed on the chamber output side. The application of the user determines, which of the two sysstms is best suited. Plasma enhanced etching and coating processes encounter a growing importance in the semiconductor industry. At the same time applications have expanded to improvement procedures of metallic surfaces and production of computer hard discs, based on plasma processes as reactive vapour deposition and sputtering. For many of these applications pressure control via the gas input is sufficient. But the increasing demands on the quality of the micro structures with modern surface processes can only be satisfied by independent control of the gas flow and the process pressure. Pressure control independent of the gas flow is achieved by controlling the effective pumping speed of the vacuum pump. The presented paper starts with the general theory of pressure control, and deals with the various aspects of pressure control, including downstream pressure control with throttle valvê, adaptive controller and sensor.     

气体鼓泡强化超滤分离木聚糖酶和β-木糖苷酶

研究了木聚糖酶和β-木糖苷酶的超滤分离过程中,气体鼓泡的作用、气体流量、液相流量和操作压强对溶剂透过率和分离因数的影响.结果发现,通入少量的空气即能显著改善溶剂透过率和分离因数,这种改善效果与操作条件相关,液相进料速度较低、操作压强较高时,气体鼓泡所产生的效果较为明显.在实验条件下,空气的通入可使溶剂透过率增加近60%,分离因数提高了9倍左右,增加到了36倍.适宜的空气流量为25~50 mL/min;在气体鼓泡的情况下,溶剂透过率随操作压强线性地增加,而分离因数不受操作压强影响.