隔膜泵大直径橡胶隔膜变形及应力数值分析

橡胶隔膜是大型隔膜泵设备的核心零件,了解和掌握大直径隔膜在工作过程中的变形状态和应力状态,不仅能实现隔膜结构优化,提高隔膜使用寿命,也可为隔膜泵容积效率和隔膜利用率指标的综合设计提供有用数据。由于隔膜工况复杂,采用测试方法获得隔膜工作中的变形和应力状态较为困难,成本高,本文利用数值方法对隔膜泵工作过程中大直径隔膜的运动过程进行模拟,较为准确的获得了隔膜的变形和应力结果,为隔膜泵隔膜结构设计和选型提供理论数据。     

隔膜泵橡胶隔膜头部密封结构的有限元分析与优化

利用有限元软件ANSYS对隔膜泵橡胶隔膜密封结构进行有限元建模与计算,计算得到该结构在工作状态下的变形、应力以及最大接触压应力,通过密封结构的最大接触应力失效准则,为设计提供参考依据。并对橡胶隔膜头部密封尺寸进行优化,解决隔膜密封结构的密闭性与失效问题。     

液压驱动隔膜泵控制系统总体设计

液压驱动隔膜泵是一种新型的隔膜式浆体管道输送泵,具有广阔的应用前景。控制系统作为液动隔膜泵至关重要的组成部分,能否准确、灵敏、可靠地工作将直接影响液动隔膜泵的工作性能和隔膜的寿命。简介了液动隔膜泵的结构及工作原理,利用PLC对液动隔膜泵的控制系统进行了总体设计;分析了控制系统的组成和功能,介绍了各控制信号的获取方法和隔膜极限位置的控制方法。PLC控制系统能够保证液动隔膜泵的工作性能,使其运行平稳,调节灵活。     

圆角尺寸对隔膜泵隔膜室盖结构强度的影响对比分析

隔膜室盖是大型隔膜泵液力端的关键部件之一,在隔膜泵的现场实际运行过程中,隔膜室盖因受到隔膜腔内的压力与连接螺栓的螺栓力作用而在圆角附近产生应力集中,由此产生的隔膜室盖变形成为降低隔膜泵液力端工作效率的主要原因。本文应用有限元软件ANSYS对不同圆角尺寸下的隔膜室盖进行静强度分析以对不同圆角尺寸隔膜室盖的应力集中和变形量进行对比,从而在一定范围内得出圆角尺寸对隔膜室盖应力集中的影响规律,对隔膜泵的设计与研发具有一定的理论指导意义。     

GMB200-2.5型隔膜泵机组设计要点分析

隔膜泵的冲次n和隔膜直径D为影响隔膜泵性能和结构的主要参数。本文主要介绍隔膜泵机组技术参数的合理匹配以及隔膜行程控制系统设计分析。     

阀体的密封结构对小隔膜使用寿命的影响

小隔膜是往复式活塞隔膜泵中关键橡胶件之一,其使用寿命直接关系到隔膜泵的运行状况。简要介绍小隔膜的材质、几何结构和作用之后,将三个小隔膜应用实例通过有限元分析其最大应力和应力最大位置,确定了其中一种实例作为小隔膜密封的首选方案。最后对小隔膜价值做了反向论证。     

隔膜室盖螺母液压拆装工具在隔膜泵中的应用

越来越多的用户需要高压大流量的隔膜泵,隔膜泵结构中的承压件大多是螺栓连接,螺栓的拧紧和拆卸已成为一个重要的问题.我公司也曾经出现过螺栓断裂造成设备停机,影响生产的情况,所以我们分析了原因,借鉴外国的先进技术.研制了隔膜室盖螺母液压拆装工具.本文介绍了螺栓的预紧力,拉伸的胡克定律和隔膜室盖螺母液压拆装工具的结构原理,及使用方法.     

SGMB系列隔膜泵

由沈阳有色冶金机械总厂生产制造的SGMB系列隔膜泵为卧式双缸双作用往复式隔膜泵,用橡胶隔膜把输送的浆液与泵的活塞、缸套等运动部件分隔开来,使它们在清洁的油中工作,因而能够输送腐蚀性、磨蚀性物料。 该系列隔膜泵主要特点:①排量高、油耗低、吸入性能好、使用寿命长。②自动化水平高,操作简单方便。③设有隔膜保护系     

引进高压隔膜泵的特点及使用性能分析

隔膜泵具有寿命长、油耗低、效率高、产能大等多项优点,本文对由荷兰引进的隔膜 泵的特点和使用性能做一介绍和分析。     

高原隔膜泵隔膜行程控制系统

以西藏华泰龙矿业甲玛铜多金属矿尾矿输送DGMB255／11三缸单作用隔膜泵为例,概述其主要组成部分及分类,介绍其功用、原理和特点;论述其总体构造及其在设计过程中需要综合考虑的客观因素;重点介绍高原隔膜泵隔膜行程控制系统的结构及工作原理,通过对隔膜行程控制系统的具体分析、计算,确定了高原隔膜泵隔膜行程控制系统的气源供气压力、供气流量、补油压力、单位时间内补油量等各项参数,这些参数的正确设定为高原隔膜泵隔膜行程控制系统的设计提供了一种理论依据,亦是高原隔膜泵可靠、稳定运行的必要条件。     

基于有限元的隔膜泵隔膜行程设计

隔膜是隔膜泵的关键件,隔膜行程的控制对隔膜的使用寿命有很大影响,本文采用有限元方法对隔膜行程进行分析,并与实验结果进行比较研究,有限元分析结论与实验结果基本吻合,为隔膜行程的生产设计提供了一种有限元理论分析方法,具有工程应用价值。     

Diaphragm pacing for respiratory insufficiency

Diaphragm pacing (DP) by electrical stimulation of the phrenic nerve offers important advantages to a highly select group of patients with respiratory paralysis. The patient wears an external radiofrequency (RF) transmitter over an implanted receiver, and a stimulating current is induced without the need for any transcutaneous wires. We review the conditions and requirements of patients who may benefit most from DP. We outline the preoperative evaluation and procedures for surgical implantation. We discuss the risk of diaphragmatic fatigue posed by initiation of DP and the use of gradual conditioning to limit this problem. Other problems encountered by patients in the course of DP can be minimized by well-instructed home caregivers and by systematic medical follow-up. Although a few patients derive considerable benefit from DP, many patients with respiratory paralysis are better treated by less invasive means such as nasal bilevel positive airway pressure or intermittent positive pressure ventilation, which we also review.     

浅谈地下连续墙施工问题的处理

文章主要论述地下连续墙施工过程中所遇到问题的处理方法,并采用水泥搅拌桩复合处理塌方事故。     

Diaphragm replacement. An animal experiment study

OBJECTIVE: The study was designed to test the hypothesis that a dentifrice with fluoride at the same concentration (1000ppm) from two sources, ie NaF and NaMFP, would provide a greater treatment effect than one with NaMFP alone. BASIC RESEARCH DESIGN: A double blind clinical trial with random assignment of children to one of two groups was carried out for three years. The two trial groups were similar at the outset in respect to those variables which might otherwise have affected the outcome, including age and gender, with means per subject of 98.4 sound surfaces and 2.2 decayed and filled surfaces in each group initially. CLINICAL SETTING: Secondary schools in the Isle of Wight, UK, an area of diminished caries experience. PARTICIPANTS: One thousand six hundred and thirty-three children aged initially 10-12 years. INTERVENTIONS: A test dentifrice containing 500ppm NaF plus 500ppm NaMFP, and a standard active control product containing 1000ppm NaMFP. Products were used in the home. OUTCOME MEASURES: Increment of DF teeth and surfaces measured over 36 months. RESULTS: After three years, mean approximal surface increments were 3.6 new DFS in the control group and 3.1 in the test group, a difference 13 per cent (P < 0.05). Thirty-four per cent of the subjects were caries free at the outset. In the 1075 subjects with caries at the outset, the total mean increment on all surfaces was 7.2 new DFS in the control group and 6.4 new DFS in the test group, a difference of 11 per cent (P < 0.05). However, those subjects with initial caries had approximal surface increments of 4.8 new DFS in the control group and 4.0 new DFS in the test group, a difference of 16 per cent (P < 0.01). Included separately along with the conventional rubric were enamel white spots on which no differential treatment effect was observed. CONCLUSIONS: Under the conditions of this study, the regular use of a dentifrice containing 1000ppm fluoride from two sources provided a significantly greater treatment effect than one with fluoride from a single source.     

隔膜电解技术的应用与发展

隔膜电解技术是电渗透技术和电解技术结合在一起的一门技术，它广泛的应用于化工、环保、有色冶金等领域。本文介绍了隔膜电解技术的基本原理，评述了它的研究现状和研究发展方向。     

Diaphragm activation with intramuscular stimulation in dogs

We studied in 10 supine anesthetized dogs diaphragm contraction produced by electrical activation with intramuscular electrodes surgically implanted in the ventral surface of the diaphragm and compared this with activation of the ipsilateral phrenic nerve (C5, 6, and 7) before it entered the thorax. Repetitive 40-Hz pulse trains with supramaximal current stimulus were used after hyperventilation of the animals to apnea. A single intramuscular electrode within 1 to 2 cm of the site of phrenic nerve entry into the diaphragm produced a mean transdiaphragmatic pressure of 12.0 cm H2O +/- 0.97 SE and mean tidal volume of 0.27 L +/- 0.04 SE. Mean values observed with phrenic nerve stimulation were not statistically different, and both electrode systems produced equivalent outward abdominal motion and upper rib cage paradox, as monitored by inductive plethysmography. There was no difference in gas exchange during stimulation with a single hemidiaphragm electrode and mechanical ventilation compared at the same tidal volume and respiratory rate. Blockade of neuromuscular transmission with curare eliminated intramuscular and phrenic nerve stimulation proportionately, suggesting that activation of the diaphragm is dependent in both cases on the phrenic nerve. This technique does not entail manipulation of the phrenic nerve and may have clinical application as an alternative technique for diaphragm pacing.