泥漿粘度測量儀的結構設計【含CAD圖紙+文檔】
泥漿粘度測量儀的結構設計【含CAD圖紙+文檔】,含CAD圖紙+文檔,泥漿,粘度,測量儀,結構設計,cad,圖紙,文檔
泥漿黏度測量儀結構設計
附錄2 外文文獻
The new clay mud and its improvement effects of tunnels
a b s t r a c t
During tunneling process by earth pressure balance (EPB) shield, the strata containing large amounts of sand and gravel are often encountered. The excavated soil in the shield chamber has poor plastic flow and larger permeability, so it leads to the difficult construction of the EPB tunnel. In order to ensure tunneling advance successfully, the excavated soil must be improved by adding modified materials to change its physical and mechanical properties, and make it to have a good plastic flow state, low friction angle and low permeability.Soil improvement techniques can guarantee the stability of excavation face, achieve the balance advance of shield tunnel, reduce machinery load and the ground settlement, and improve the excavation speed. The existing mud used in engineering practice is the dispersing mud and water system whose compositions are bentonite and water. Both the composition and function are simple. The existing mud has various problems, such as large amounts of waste mud emission, difficulties in controlling mud indicators, large areas for mud treatment and large uses of new mud materials and environmental pollution. In this paper, a kind of environmentally friendly clay mud was developed, and the laboratory and field tests were conducted to verify its adaptability and superiority.
1. Introduction
With the development of shield construction technology and soil improvement techniques,shield construction technology is widely used in the underground construction, especially in the poor soil and complex geological conditions with high groundwater level. Currently, in the EPB shield construction exists many problems, for example,in the clay-silt layer, the cohesive soil will affect the flow plastic state of soil in the excavation chamber and the penetration of ground-water. In the sand soil layer, the cutter head of the shield machine wears quite seriously. In the gravel layer containing groundwater,the greater seepage pressure is applied to the excavation face, the soil pressure is difficult to control in the excavation chamber, and the boiling phenomenon may appear, the cutter head wears seriously as well. In the sand and pebble layer, the friction resistance among the sand–pebble particles is too large to obtain the good liquidity of the excavated soil. Therefore, when the excavation chamber and the spiral conveyor are full of excavated soils, the torque of the cutter head and the thrust force of the shield machine will increase, even if the spiral conveyor does not work (Yang and Li, 2012). In addition, in order to make the shield tunneling successful, the modified materials(e.g., mud, bubble and polymer) must be injected into the excavation face and excavation chamber (even in the spiral conveyor) to improve the excavated soil condition, and have a good plastic flow, have low friction angle and low permeability to guarantee the stability of excavation face, achieve the balance advance of shield tunneling, reduce the ground settlement, and improve the excavation speed.Currently, the research and application of soil improvement techniques lack normative standards, such as the selection of the conditioner types, mud composition, methods of determination, control of the performance parameter and objective, and selection and controlof the injection parameter, almost all of them are based on the engineering experience or the trial and error in the construction field.Usually, the simple slump cone test was used to measure the behavior of the conditioned soil scarried out the mixing tests to measure the power consumptionof a mortar mixer and assess the effectiveness of the soil conditioner.The vanesheardeviceis applied to measure the shear strength of soil mixtures under different pressures and vane velocities, and even evaluate the property of soil conditioned with foam and polymer additives.
2. Preparation of a new mud and its performance analysis
2.1. Preparation of a new clay mud
During the EPB shield tunneling, the excavated soils in the excavation chamber should have a good plastic flow property to ensure that the thrust force applies evenly on the excavation face, and maintains the stability of the excavation face. At the same time, the excavated soils could be discharged smoothly through the screw conveyor. In
this study, the improved material for the sand-gravel layer is the mineral mud. Based on the knowledge of drilling fluids, combined with the existing research results, the indoor experiments combining with the evaluation methods were conducted to select the mud mate-rials. Through the analysis of a series of indoor experiments, the mud materials were determined as water, bentonite, xanthan gum, sodium carbonate, and clay particles.
Due to the particularity of the shield tunneling, the related performance of the new clay mud must be tested before it is used. In this study, the relative density, viscosity (including the marsh funnel viscosity, apparent viscosity, plastic viscosity, dynamic shear, gel strength, liquidity index and consistency coefficient), conventional static filter loss (API standard, which refers to the filter loss through the filtrate area with 4580 mm 2 within 30 min in the state of the normal temperature and 0.689 MPa.) and pH value of the new clay mud were measured to estimate whether they meet the requirements of the construction site. In order to obtain the better mud proportion,the orthogonal experiments were also conducted. It is noted that the content of raw material refers to the percentage of material mass and water mass.
2.2. Performance comparison of the existing mud and new clay mud
Until now, the existing mud used in the EPB shield tunneling is the pure bentonite mud with 9% bentonite, namely, a ton of water has 90–120 kg bentonite. It is noted that, in order to facilitate the description, the new clay mud developed in this study be referred to as clay mud A, and the existing mud used in the EPB shield tunneling be re-
ferred to as mud B. Therefore, the consistency of the mud B is high, and does not easily flow. Also, the mud B is difficult to flow out of the test tube after standing, and it is not conducive to the mud pumping systems. The apparent viscosity of the mud B is 13.5 mPa·s, the plastic viscosity is 3 mPa·s, and the marsh funnel viscosity is 40; compared
with the clay mud A, mud B has a low viscosity. In addition, clay mud A has a high viscosity, so it can avoid mud spill, conducive to film, and ensure the stability of excavation face. Meanwhile, for the large size gravel layer, high viscous clay mud can prevent the deposition of gravel in the excavation chamber, and it is conducive to con-
veying excavated soils. Therefore, the performance of the new clay mud A developed in this study is better than that of mud B used in the EPB shield tunneling.
3. Laboratory test of the new clay mud
3.1. Laboratory design for the improvement of the new clay mud
To estimate the improvement effects of the new clay mud A, it is necessary to carry out some related experiments which contain soil mixing test, friction coefficient test, adhesive resistance test and slump test to fully analyze the improvement effects.
3.1.1. Soil mixing test
Soil mixing test mainly imitates the real mixing process in the excavation chamber. By this test, the improvement effects of the new clay mud can be estimated, and take control of the content of clay mud by the change of power of mixing. Soil mixing test experiment contains mixer and power meter, as shown in Fig. 1.
3.1.2. Friction coefficient test
The main purpose of taking friction coefficient test is to imitate the process of soil and the steel friction while the spiral unearthed device and getting the adhesion coefficient of drag. Achieve the instant adhesive resistance when the simulation shield machine starts working again. By the size of the force, the coefficient resistance of the soil act- ing on the steel can be determined. If the force is too large, the fluidity is too great and it needs more power to start the machine. The measuring machine is shown in Fig. 4
.
3.1.4. Slump test
The slump test is needed to simulate the fluidity state of the conditioned soil. If the slump has no obvious change, there is no need to take the slump test because the following test is easily affected by the slump. The slump shouldn't be taken until the clay mud has certain effect on the soil. The requirement of the slump needs a certain series of tests to be determined. Based on the early experiments, the knowledge about slump test has been handled partly and the time of taking the test can be controlled easily. Each time takes 3–5 groups of tests and takes the average of the data. The experiment device for slump is the standard cave in barrel, as shown in Fig. 5.
3.2. Laboratory test and analysis of the new clay mud
To evaluate the improvement effects of the new clay mud, both clay mud A and mud B were used to improve the round gravel soil and sandy soil to comparatively analyze the advantage of clay mud A.. Mixing test. Fig. 6 describes the comparative curve of the net power of clay mud A and mud B. From Fig. 6, it can be seen that the net mixing powers of the two improved soils obviously decrease after adding the clay mud A and mud B; the effects of the two muds on the mixing power are roughly equal.
It can also be seen that, when the net power reaches zero, the excavated soil will be in the state of fluidity plastic. The net power of clay mud A is smaller than mud B, so the effects of decreasing the mixing power of clay mud A are better than mud B.
4. Field test to evaluate the effects of the new clay mud
4.1. Background
In order to estimate the effects of the new clay mud on the property of plastic flow of the excavated soils, the region between Yuquan station and Fanjiacun station of the subway line 10 in Beijing was chosen to conduct field tests.
4.1.1. Geological condition
Through investigation, in the region of shield tunneling, the maximum depth of the discovered layer is 42.7 m, where it contains miscellaneous filled soil, sandy silt, pebble bed, and round gravel soil. The major tunnel structure lies in the pebble bed. The particle size is usually within 2–10 cm, the maximum size reaches 15 cm, fine medium sand accounts for 30%, the parts of the layer contains floating stones which accounts for over 20% and the distribution is very random.The basic property of the layer is the loosing structure without cement, and with the distribution of different particle sizes. In addition,the void of the gravels was mainly filled with medium and rude sand without water.
4.1.2. Main form of the shield machine
The cutterhead of the shield machine in this region is designed to six spokes with six panel, the cutters contain tearing knife, scraping knife, crushed stone knife, copying cutter, surrounding protecting knife, etc. The copying cutter is pushed by the hydraulic pressure,the size of the cutter head is 6240 mm long, and its aperture opening ratio is 41%. The dimension of the maximum particle getting through the cutter can reach 500 mm × 300 mm.
4.2. Field test
The new clay mud A developed in this study was used in the field test. According to the field condition, the volume of the mixing tank was 3 m 3 , and it was filled with water. About 3% of the bentonite and sodium carbonate and medium grained clay were added into the mixing tank and mixed together, and then 1% of the bentonite and xanthan gum were mixed and added into the mixing tank using 2 mm granule sieve to prevent caking, as shown in Fig. 14. After mixing well (about 15 min), the new clay mud was transferred from the mixing tank to the storage pool, whose volume is 50 m 3 . The mud cannot be used until 12 h later.
4.3. Analysis of field test results
The typical layer in the region from ring 661 to ring 665 (each ring is 1.2 m) was chosen to conduct the field tests. In order to analyze and compare the improvement effects of the clay mud A developed in this study, the ring 655 to 660 was also improved by the existing mud B for comparing purpose.
5. Conclusions
In this study, a new type of clay mud was developed, and lots of laboratory tests and field tests were carried out to test and verify its improved performance. The following conclusions can be summarized as:
The work presented in this paper was supported by the National Natural Science Foundation of China (41202220), the Research Fund for the Doctoral Program of Higher Education, the Fundamental Research Funds for the Central Universities and the Research Fund for Key Laboratory on Deep GeoDrilling Technology, Ministry of Land and Resources.
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本科畢業(yè)論文(設計)開題報告
論 文 題 目: 泥漿黏度測量儀結構設計 學 院: 機械工程學院 專 業(yè) 、班 級: 機械設計制造及其自動化 學 生 姓 名: 指導教師(職稱):
年 12 月 28 日填
畢業(yè)論文(設計)開題報告要求
開題報告既是規(guī)范本科生畢業(yè)論文工作的重要環(huán)節(jié),又是完成高質(zhì)量畢業(yè)論文
(設計)的有效保證。為了使這項工作規(guī)范化和制度化,特制定本要求。一、選題依據(jù)
1. 論文(設計)題目及研究領域;
2. 論文(設計)工作的理論意義和應用價值;
3. 目前研究的概況和發(fā)展趨勢。二、論文(設計)研究的內(nèi)容1.重點解決的問題;
2. 擬開展研究的幾個主要方面(論文寫作大綱或設計思路);
3. 本論文(設計)預期取得的成果。三、論文(設計)工作安排
1. 擬采用的主要研究方法(技術路線或設計參數(shù));
2. 論文(設計)進度計劃。四、文獻查閱及文獻綜述
學生應根據(jù)所在學院及指導教師的要求閱讀一定量的文獻資料,并在此基礎上通過分析、研究、綜合,形成文獻綜述。必要時應在調(diào)研、實驗或實習的基礎上遞交相關的報告。綜述或報告作為開題報告的一部分附在后面,要求思路清晰,文理通順, 較全面地反映出本課題的研究背景或前期工作基礎。
五、其他要求
1. 開題報告應在畢業(yè)論文(設計)工作開始后的前四周內(nèi)完成;
2. 開題報告必須經(jīng)學院教學指導委員會審查通過;
3. 開題報告不合格或沒有做開題報告的學生,須重做或補做合格后,方能繼續(xù)論文(設計)工作,否則不允許參加答辯;
4. 開題報告通過后,原則上不允許更換論文題目或指導教師;
5. 開題報告的內(nèi)容,要求打印并裝訂成冊(部分專業(yè)可根據(jù)需要手寫在統(tǒng)一紙張上,但封面需按統(tǒng)一格式打?。?。
一、選題依據(jù)
1. 論文(設計)題目
泥漿粘度測量儀結構設計
2. 研究領域
測量原理和結構設計
3. 論文(設計)工作的理論意義和應用價值
粘度測量儀已被廣泛使用,而且測量設備不斷更新,測量原理也不斷改進,所以完成本題有較大的實用價值,通過本題目的實踐對于提高學生的實際工作能力有一定的指導意義,也可以幫助學生更加了解這個裝置,要求學生能正確運用所學知識,培養(yǎng)學生查閱有關標準的聲測能力,進而促進學生具有創(chuàng)新的思維能力。
隨著社會的發(fā)展,不止在泥漿粘度的測量方面,生活中的各個領域也都需要進行粘度的測量,因此粘度計得發(fā)展也越來越受到重視,在一些緊急狀況下運用高精度的測量儀器不太現(xiàn)實,所以運用一些簡單的一起進行測量的使用越來越頻繁,因此此設計有一定的應用價值。
4. 目前研究的概況和發(fā)展趨勢國外的發(fā)展狀況
粘度計的發(fā)展在國外一直處于領先的水平。目前國外對于嵌入式系統(tǒng)的粘度計研究已經(jīng)有了相關成果,BROOKFIELD 公司也推出了一些相關產(chǎn)品,但是其在觸摸屏上能完成的工作較少,只是復刻了傳統(tǒng)粘度計的操作方法,并讓操作變得更直觀一些, 對于不連接 PC 時的功能沒有更好的擴充。此粘度計具有直觀的彩色觸摸顯示屏操作, 隨意的轉速控制,自動掃描式測量,無需電腦即可進行流變 數(shù)據(jù)分析等優(yōu)點。并且具有良好的可擴展性。
國內(nèi)發(fā)展狀況
粘度計在國內(nèi)發(fā)展較少,就嵌入式系統(tǒng)而言,國內(nèi)的相關研究更少,主要集中在粘度計功能擴展的一些討論。在國內(nèi)對于旋轉式測量儀有較多研究,傳統(tǒng)的粘度計有機械指針式和數(shù)字液屏顯示兩種類型,操作多采用按鍵操作,在不同的功能間切換需要重復按鍵數(shù)次才能完成,并且顯示效果不夠理想,多采用象征字符表示功能,可選擇的電機轉速也是有限幾個,測量功能單 一,無法實現(xiàn)自動測量,另外,測量結果的展示和保 存的功能也比較不完善,目前其最佳的方案是采用 與計算機相連實現(xiàn)數(shù)據(jù)的實時處理和保存。
粘度計的發(fā)展在國外一直處于領先的水平。目前國外對于嵌入式系統(tǒng)的粘度計研究已經(jīng)有了相關成果,BROOKFIELD 公司也推出了一些相關產(chǎn)品,但是其在觸摸屏上能完成的工作較少,只是復刻了傳統(tǒng)粘度計的操作方法,并讓操作變得更直觀一些,對于不連接 PC 時的功能沒有更好的擴充。此粘度計具有直觀的彩色觸摸顯示屏操作, 隨意的轉速控制,自動掃描式測量,無需電腦即可進行流變 數(shù)據(jù)分析等優(yōu)點。并且具有良好的可擴展性。粘度計在國外的發(fā)展原理更為廣泛,例如微機控制超聲多普勒法的粘度計。研究領域也較為廣泛,國外開始在生命醫(yī)學方面開始研究,還有食品安全方面更為簡潔的家庭使用的粘度計。
微機控制超聲多普勒法粘度計:利用超聲多普勒效應接收 液體中下落小球的頻移信號,將此信號送微機進行采集、比較 、判斷、計算并顯示出泥漿粘度 。應用本方 法能快速準確地測量多種液體的粘滯系數(shù)。
粘度計在國外還有一些發(fā)展,就嵌入式系統(tǒng)而言,國內(nèi)的相關研究更多,主要集中在粘度計功能擴展的一些討論。在國內(nèi)對于旋轉式測量儀有較多研究,傳統(tǒng)的粘度計有機械指針式和數(shù)字液屏顯示兩種類型,操作多采用按鍵操作,在不同的功能間切換需要重復按鍵數(shù)次才能完成,并且顯示效果不夠理想,多采用象征字符表示功能, 可選擇的電機轉速也是有限幾個,測量功能單 一,無法實現(xiàn)自動測量,另外,測量結果的展示和保 存的功能也比較不完善,目前其最佳的方案是采用 與計算機相連實現(xiàn)數(shù)據(jù)的實時處理和保存。
超聲波粘度測量法:測量方案和裝置“測定超聲波聲壓的相對衰減與液體的粘度的關系,并考慮到修正擴散衰減的需要,固定傳播距進行測量”
并且在國外粘度計的發(fā)展也較為智能化,國外還有一些智能粘度計和全自動微量落球粘度計。這些粘度計多適用于比較高端的場合,在工程領域使用較多的還是機械式的旋轉式粘度計。
總而言之,粘度計在國內(nèi)外的發(fā)展都比較迅速,而且此行業(yè)的關注程度也越來越高, 國內(nèi)外的工程師對結構的設計也越來越有更多的見解。
粘度計的發(fā)展趨勢
未來粘度計的發(fā)展趨于簡潔化、多元化、自動化的方向發(fā)展。未來的粘度計的使用不僅僅使用在工程系方面。例如自動粘度計,自動粘度計用于對毛細血管粘度計的自動清洗、烘干,全過程自動控制,具有方便、快速、可靠等特點。用于清洗品氏玻璃毛細血管粘度計,也用于芬氏,奧氏,改良奧氏及逆流式粘度計的清洗。儀器的設計制作更加合理、精良,操作更加方便,使用更加安全,具有洗排,沖洗,烘干等多功能。對粘度計內(nèi)各種各種不同粘度的潤滑油,瀝青及含蠟較高的油污均有理想的測量效果。
二、論文(設計)研究的內(nèi)容
1. 重點解決的問題
重點選擇測量原理及設計結構
2. 擬開展研究的幾個主要方面(論文寫作大綱或設計思路)
1)了解粘度計的結構與用途
2) 找出一些粘度計的測量原理
3) 根據(jù)測量原理計算一些必要的測量數(shù)據(jù)
4) 根據(jù)測量數(shù)據(jù)得出儀器的結構參數(shù)
5) 根據(jù)結構參數(shù)畫出零件圖
6) 完成整體的裝配圖
3. 本論文(設計)預期取得的成果
本設計可以設計出一個可以在一定約束條件下(電源頻率、周圍空氣溫度及濕度、周圍空氣的不含有腐蝕物質(zhì)元素),并且能得出較小測量誤差的旋轉式粘度計的說明書以及裝配圖。
三、論文(設計)工作安排
1.擬采用的主要研究方法(技術路線或設計參數(shù));
(1)研究方法主要是利用測量原理進行儀器結構參數(shù)的運算
1) 根據(jù)液體的種類不同測出液體的絕對粘度和恩氏粘度計算公式
2) 液體若是塑性液體,找出塑性粘度的計算公式
3) 液體若是假塑性流體,找出其假塑性粘度的計算公式
4) 根據(jù)計算公式逆推測量所需要的參數(shù)
5) 得出測量參數(shù)再計算出測量儀的結構參數(shù)
(2)對測量進行模擬模擬測量儀的技術條件1) 測量儀的工作條件
2) 轉速誤差
3) 變差
4) 環(huán)境溫度對測量儀的影響
2.論文(設計)進度計劃第 1 周:收集相關資料
第 2 周:閱讀整理所收集資料
第 3 周:撰寫開題報告初稿交指導老師修改
第 4 周:完成開題報告,并進行答辯
第 5 周:測量儀結構特點分析
第 6 周:測量儀總體方案設計
第 7 周:測量儀主要參數(shù)分和選擇
第 8 周:測量儀的結構設計 繪制裝配圖
第 9 周:測量儀的結構設計 修改完什裝配圖
第 10 周:繪制粘度測量儀零件圖
第 11 周:繪制粘度測量儀零件圖
第 12 周:撰寫粘度測量儀設計說明書
第 13 周:修改完什粘度測量儀設計說明書
第 14 周:翻起外文資料
四、需要閱讀的參考文獻
[1]孫恒,陳作模,葛文杰,機械原理[M] 北京:高等教育出版社,2013.5 [2]濮良貴,陳國定,吳立言,機械設計[M] 北京:高等教育出版社,2013.5
[3]劉延俊,關浩,周德繁,液壓與氣壓傳動[M] 北京:高等教育出版社,2007.5 [4]劉延俊,液壓與氣壓傳動[M] 北京:機械工業(yè)出版社,2012.1
[5]聞邦椿,機械設計手冊(第 2 卷)減速器[M] 北京:機械工業(yè)出版社,2010.1 [6]聞邦椿,機械設計手冊(第 3 卷)起重運輸機械零部件與操作件[M] 北京:機械工業(yè)出版社,2010.1
[7] 聞邦椿,機械設計手冊(第 4 卷)液壓傳動[M] 北京:機械工業(yè)出版社,2010.1
[8] 陳 徐,F(xiàn)ANN35SA 系列旋轉粘度計[J] 石油儀器 1989 20~28
[9] 李煥平 ,地質(zhì)工程中水泥漿主要流變參數(shù)的確定與分析[J] 工程技術 2014
[10] 劉希民,直管式粘度計的研制[J] 化工自動化及儀表 2012
[11] 張峰,泥漿性能檢測系統(tǒng)設計[J] Transducer and Microsystem Technologies 2015
[12] 曹麗,液體粘度在線測量的方法研究[J] 儀器儀表學報 2010
[13] 郭敏,一種測量泥漿粘度的新方法_微機控制超聲多普勒法[J] 中國陶瓷 2001
[14] 付曉穎,鉆井液綜合參數(shù)在線測量方法的研究[J] 甘肅科技 2015
[15] 耿宏章,高溫高壓油氣水混合液粘度測量裝置[J] 石油儀器 2003 [16]F.chen.H.Jiang.X.bai.W.Zheng.Evaluation the performation of sodium metaborate as a novel alkali in alkali/surfactant/polymer flooding J. Ind. Eng.Chen.19(2013)450-457 [17]W.Kang.L Yi Q Baoyan, L Guangzhi,Y Zhou Q Li Highly porous 3D networks preparation and the potential application in oil-water sepation Chen Eng J302(2016)1-11
附:文獻綜述或報告
文獻綜述
1 引言
粘度測量在食品、石油、化妝品和涂料等各行各業(yè)中起著非常重要的作用。目前在建筑方面也來越受關注,建筑方面泥漿粘度測量最為重要。所以粘度計的市場也逐年增大,對粘度計的性能、功能和使用體驗也提出了一定的要求。
并且目前正在從更先進的技術方面發(fā)展。即利用超聲波來完成測量。超聲波液體粘度測量與其它測量方法相 比 , 以其獨有的連續(xù)測 量特點 , 從 5 0 年代起 在許多需要粘度控制的生 產(chǎn)過程中得到越來越廣泛的應用 。近些 年來 , 人們又試圖用它 來測 量和 連續(xù)監(jiān) 視石 油 鉆井泥漿的粘度 , 現(xiàn)場使用后發(fā)現(xiàn) , 對于石油泥 漿 , 超聲粘度 計 幾乎完全不 能準確有效地工作。 最新分析研究〔1〕指 出, 現(xiàn)有超 聲粘度計 都是利用液 體對振子的切變阻抗來測量粘度 , 而這種切變聲阻抗方法只 限于純牛頓液體 , 對石油泥 漿等非純 牛頓液體不適用 。
2 粘度
粘度是陶瓷泥漿的重要物理性質(zhì)之一,陶瓷泥漿粘 度的測量在工業(yè)生產(chǎn)和基礎學科研究中具有十分重要的 意義。粘度有相對粘度和絕對粘度之分。相對粘度也稱 條件粘度,包括恩氏粘度,賽氏粘度和雷氏粘度等。粘度是液體內(nèi)部阻 礙相對流動 的一種特性 , 它是液體分子之 間、 固體顆粒之 間及液體 分子與固體顆粒之 間產(chǎn)生摩擦的結果 。 不 同類型的液體有不同的粘度 。
2.1 粘度的影響因素
影響泥漿粘度的因素很多,如原料的礦物組 成,顆粒的形狀及大小,分散狀態(tài), 電解質(zhì)的種類和用量, 泥漿的溫度,用水量,泥漿的陳腐攪拌及真空處理等都 影響泥漿的性能,從而影響泥漿的粘度。、
2.2 恩氏粘度
恩氏粘度是試樣在某一溫度時從恩氏粘度計流出 100mL 所需的時間(即粘度計的漿值)與蒸餾水在 30℃ 時流出相同體積所需的時間(即粘度計的水值)之比。 在實驗過程中,試樣流出應成為連續(xù)的線狀。溫度 T 時 的恩氏粘度,用符號 Et 表示, 單位 :條件度 ;試樣在試 驗溫度 T 時從粘度計流出 100mL 所需的時間(秒)用Jt 表示
2.3 絕對粘度
旋轉粘度計同步電機以穩(wěn)定的速度旋轉,連接刻度 圓盤,再通過游絲和轉軸帶動轉子旋轉。如果轉子未受 到液體的阻力,則游絲、指針與刻度圓盤同速旋轉,指 針在刻度盤上指出的讀數(shù)為“0”。反之,如果轉子受到 液體的粘滯阻力,則游絲產(chǎn)生扭矩,與粘滯阻力抗衡, 后達到平衡,這時與游絲連接的指針在刻度圓盤上指 示一定的讀數(shù)(即游絲的扭轉角)。
3、粘度計及粘度計的發(fā)展狀況
3.1 粘度計
粘度計是測量一些物質(zhì)粘度的一種儀器,并且粘度測量越來越受到重視,因此粘度計的研究變成了熱門話題。粘度計的研究主要是研究其研究原理和研究方法,常見的測量儀有毛細血管式、旋轉式和落球式。近年來在粘度計的測量原理上也有了新的突破。比如:超聲式、沉淀式等的測量方法。
3.2 粘度計的發(fā)展狀況
3.2.1 國內(nèi)粘度計的發(fā)展狀況
國內(nèi)粘度計的發(fā)展領域較為狹小,研究領域僅限于機械工程系、建筑工程系和生物工程系,運用最廣泛的行業(yè)是石油行業(yè)。測量原理也比較單一,例如直管式粘度計, 旋轉式粘度計等機械式的粘度計。
直管式式粘度計:主要由測 量系統(tǒng)和數(shù)據(jù)采集與處理系統(tǒng)兩部分組成,測量 系統(tǒng)由直徑為 D 的直管、兩個壓力變送器、科里 奧利流量計、阻尼器、電磁閥、節(jié)流閥、旁路閥、兩 個止回閥、泥漿泵及溢出口等組成,主要完成被測 泥漿的實時輸送、流量測量、密度測量、溫度測量、 直管段的壓差測量及管路的定期清洗等,阻尼器 用于消除流體流動時的脈動。數(shù)據(jù)采集及處理系 統(tǒng)由單片機數(shù)據(jù)采集單元、數(shù)字顯示、數(shù)據(jù)輸出端 口、泥漿泵及電磁閥控制信號驅動電路等組成。此粘度計實現(xiàn)了鉆井液等流體的在線測量,解決了離線 粘度測量實時性差和監(jiān)測控制不及時的缺陷。
旋轉式粘度計:運用機械結構使液體混合均勻,然后再測量其運動速度以得到液體的粘度,此測量方法測量結果較為精準并且較容易實現(xiàn)。把測得的液體可以稱為牛頓流體(在層流區(qū)內(nèi), 這種液體的粘度是一個不 隨速度梯度 變化的常數(shù) , 它的流變曲線是一 條通過原點的直 線)。牛頓流體的流變方程遵守牛頓定律。因此就得出了測量的原理。
粘度是液體內(nèi)部阻 礙相對流動 的一種特性 , 它是液體分子之 間、 固體顆粒之間及液體 分子與固體顆粒之 間產(chǎn)生摩擦的結果 。 不 同類型的液體有不同的粘 度 。 因此可以在液體旋轉時測得液體的旋轉速度進而得出液體的粘度。 ,
對于機械方面的粘度計,旋轉式的粘度計最為貼近,所以我在這次的畢業(yè)設計中選出了旋轉式粘度計。
3.2.2 粘度計在國外的發(fā)展狀況
粘度計的發(fā)展在國外一直處于領先的水平。目前國外對于嵌入式系統(tǒng)的粘度計研究已經(jīng)有了相關成果,BROOKFIELD 公司也推出了一些相關產(chǎn)品,但是其在觸摸屏上能完成的工作較少,只是復刻了傳統(tǒng)粘度計的操作方法,并讓操作變得更直觀一些, 對于不連接 PC 時的功能沒有更好的擴充。此粘度計具有直觀的彩色觸摸顯示屏操作, 隨意的轉速控制,自動掃描式測量,無需電腦即可進行流變 數(shù)據(jù)分析等優(yōu)點。并且具有良好的可擴展性。粘度計在國外的發(fā)展原理更為廣泛,例如微機控制超聲多普勒法的粘度計。研究領域也較為廣泛,國外開始在生命醫(yī)學方面開始研究,還有食品安全方面更為簡潔的家庭使用的粘度計。
微機控制超聲多普勒法粘度計:利用超聲多普勒效應接收 液體中下落小球的頻移信號,將此信號送微機進行采集、比較 、判斷、計算并顯示出泥漿粘度 。應用本方 法能快速準確地測量多種液體的粘滯系數(shù)。
粘度計在國外還有一些發(fā)展,就嵌入式系統(tǒng)而言,國內(nèi)的相關研究更多,主要集中在粘度計功能擴展的一些討論。在國內(nèi)對于旋轉式測量儀有較多研究,傳統(tǒng)的粘度計有機械指針式和數(shù)字液屏顯示兩種類型,操作多采用按鍵操作,在不同的功能間切換需要重復按鍵數(shù)次才能完成,并且顯示效果不夠理想,多采用象征字符表示功能, 可選擇的電機轉速也是有限幾個,測量功能單 一,無法實現(xiàn)自動測量,另外,測量結果的展示和保 存的功能也比較不完善,目前其最佳的方案是采用 與計算機相連實現(xiàn)數(shù)據(jù)的實時處理和保存。
超聲波粘度測量法:測量方案和裝置“測定超聲波聲壓的相對衰減與液體的粘度的關系,并考慮到修正擴散衰減的需要,固定傳播距進行測量”
并且在國外粘度計的發(fā)展也較為智能化,國外還有一些智能粘度計和全自動微量落球粘度計。這些粘度計多適用于比較高端的場合,在工程領域使用較多的還是機械式的旋轉式粘度計。
總而言之,粘度計在國內(nèi)外的發(fā)展都比較迅速,而且此行業(yè)的關注程度也越來越高, 國內(nèi)外的工程師對結構的設計也越來越有更多的見解。
4 粘度計的發(fā)展趨勢
未來粘度計的發(fā)展趨于簡潔化、多元化、自動化的方向發(fā)展。未來的粘度計的使用不僅僅使用在工程系方面。例如自動粘度計,自動粘度計用于對毛細血管粘度計的自
動清洗、烘干,全過程自動控制,具有方便、快速、可靠等特點。用于清洗品氏玻璃毛細血管粘度計,也用于芬氏,奧氏,改良奧氏及逆流式粘度計的清洗。儀器的設計制作更加合理、精良,操作更加方便,使用更加安全,具有洗排,沖洗,烘干等多功能。對粘度計內(nèi)各種各種不同粘度的潤滑油,瀝青及含蠟較高的油污均有理想的測量效果。
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