国产bbaaaaa片,成年美女黄网站色视频免费,成年黄大片,а天堂中文最新一区二区三区,成人精品视频一区二区三区尤物

首頁> 外文學位 >PHYSICAL SEPARATION OF AIRBORNE ASBESTOS FIBERS BY SIZE.
【24h】

PHYSICAL SEPARATION OF AIRBORNE ASBESTOS FIBERS BY SIZE.

機譯：按尺寸對航空石棉纖維進行物理分離。

獲取原文
獲取原文并翻譯 | 示例
  • 摘要
  • 著錄項
  • 相似文獻
  • 相關(guān)主題

摘要

The hazardous properties of airborne fibers are generally thought to be related to fiber diameter and length. The purpose of this study was to develop a technique for physically classifying airborne fibers on the basis of diameter and length, keeping the separated fractions in the suspended state. This would permit either fraction to be further classified, monitored by real-time instrumentation and/or used in size-related inhalation studies. Other fiber classification methods have involved the deposition of fibers onto a substrate which precludes these advantages.; In this study diameter classification was achieved by application of inertial forces, and length classification was attempted by application of electrical forces. In both cases the classification device used was an opposing-jet aerosol classifier. Diameter classification was sharpest for liquid particles, less for isometric solid particles and least for fibers. Length classification was not achieved.; Particle losses in the classifier were greatest for liquid particles, less for isometric solid particles and least for fibers. This trend is attributed to decreasing adhesiveness in going from liquid to isometric solid to fibers.; Classification efficiency is defined as the number of particles in the lower outlet flow divided by the combined number of particles in both the upper and lower outlet flows of the classifier.; In classifying both liquid and solid isometric particles, some runs were made with the classifier inlet flowrates purposely out of balance. By using an excessive flow of clean air through the lower inlet, classification efficiency was reduced for all particle sizes tested, and by using a deficient lower inlet flow, classification efficiency was increased.; It has been suggested that an approximately monodisperse aerosol could be separated out of a polydisperse aerosol by being drawn through two opposing-jet classifiers in series. As the classification efficiency usually comes no closer than a few percentage points to 0 and 100% when the classifier flowrates are carefully balanced, the twice-classified aerosol would be contaminated with a low level of over- and undersize particles. To minimize this problem, the classifier that removes the oversize fraction could be operated with a deficient lower inlet flow, while the classifier that removes the undersize fraction could be operated with an excessive lower inlet flow. The undesired fractions would thereby be more completely removed than if the inlet flows were balanced.
機譯：空氣傳播纖維的危險特性通常被認為與纖維直徑和長度有關(guān)。這項研究的目的是開發(fā)一種技術(shù)，根據(jù)直徑和長度對空氣中的纖維進行物理分類，使分離出的組分保持懸浮狀態(tài)。這將允許對任一部分進行進一步分類，通過實時儀器進行監(jiān)控和/或用于與尺寸相關(guān)的吸入研究中。其他纖維分類方法涉及將纖維沉積到基底上，這排除了這些優(yōu)點。在這項研究中，直徑分類是通過施加慣性力實現(xiàn)的，而長度分類是通過施加力進行的。在這兩種情況下，使用的分類裝置都是對流式氣溶膠分類器。對于液體顆粒，直徑分類最明顯，對于等距固體顆粒，直徑分類最不明顯，對于纖維，直徑分類最少。長度分類未實現(xiàn)。對于液體顆粒，分類器中的顆粒損失最大，對于等距固體顆粒，損失最小，對于纖維，損失最小。這種趨勢歸因于從液體到等軸測固體再到纖維的粘合性下降。分類效率定義為下部出口流中的顆粒數(shù)除以分級器上部和下部出口流中的顆?？倲?shù)。在對液體和固體等距顆粒進行分類時，需要進行一些運行，以使分類器的入口流量故意失衡。通過使用過多的清潔空氣流經(jīng)下部入口，對于所有測試的粒度，降低了分級效率；通過使用不足的下部入口流量，提高了分級效率。已經(jīng)提出，可以通過將兩個相對的射流分級機串聯(lián)吸引，將大約單分散的氣霧劑從多分散的氣霧劑中分離出來。當仔細地平衡分級機流量時，由于分級效率通常不超過0和??100％的幾個百分點，因此兩次分級的氣溶膠會被少量的過大和過小顆粒污染。為了最小化該問題，去除過大的餾分的分級機可以以不足的較低入口流量運行，而去除過小的餾分的分級機可以以過多的較低入口流量運行。因此，與平衡入口流量相比，不需要的餾分將被更徹底地去除。

著錄項

  • 作者

    HABERMAN, STEVEN A.;

  • 作者單位

    University of Cincinnati.;

  • 授予單位 University of Cincinnati.;
  • 學科 Environmental Sciences.
  • 學位 Ph.D.
  • 年度 1983
  • 頁碼 242 p.
  • 總頁數(shù) 242
  • 原文格式 PDF
  • 正文語種 eng
  • 中圖分類 環(huán)境科學基礎(chǔ)理論;
  • 關(guān)鍵詞

相似文獻

  • 外文文獻
  • 中文文獻
  • 專利
獲取原文

客服郵箱：kefu@zhangqiaokeyan.com

京公網(wǎng)安備：11010802029741號 ICP備案號：京ICP備15016152號-6 六維聯(lián)合信息科技 (北京) 有限公司?版權(quán)所有

  • 客服微信

  • 服務號