橫流槳葉式加濕調(diào)質(zhì)機(jī)的設(shè)計(jì)【說(shuō)明書(shū)+CAD+SOLIDWORKS】
橫流槳葉式加濕調(diào)質(zhì)機(jī)的設(shè)計(jì)【說(shuō)明書(shū)+CAD+SOLIDWORKS】,說(shuō)明書(shū)+CAD+SOLIDWORKS,橫流槳葉式加濕調(diào)質(zhì)機(jī)的設(shè)計(jì)【說(shuō)明書(shū)+CAD+SOLIDWORKS】,槳葉,加濕,調(diào)質(zhì)機(jī),設(shè)計(jì),說(shuō)明書(shū),仿單,cad,solidworks
編號(hào)
無(wú)錫太湖學(xué)院
畢業(yè)設(shè)計(jì)(論文)
相關(guān)資料
題目: FS400高速渦流粉碎機(jī)的設(shè)計(jì)
信機(jī) 系 機(jī)械工程及自動(dòng)化專業(yè)
學(xué) 號(hào): 0923212
學(xué)生姓名: 龔家柱
指導(dǎo)教師: 唐正寧 (職稱:副教授 )
(職稱: )
2013年5月25日
目 錄
一、畢業(yè)設(shè)計(jì)(論文)開(kāi)題報(bào)告
二、畢業(yè)設(shè)計(jì)(論文)外文資料翻譯及原文
三、學(xué)生“畢業(yè)論文(論文)計(jì)劃、進(jìn)度、檢查及落實(shí)表”
四、實(shí)習(xí)鑒定表
無(wú)錫太湖學(xué)院
畢業(yè)設(shè)計(jì)(論文)
開(kāi)題報(bào)告
題目: FS400高速渦流粉碎機(jī)的設(shè)計(jì)
信機(jī) 系 機(jī)械工程及自動(dòng)化 專業(yè)
學(xué) 號(hào): 0923212
學(xué)生姓名: 龔家柱
指導(dǎo)教師: 唐正寧(職稱:副教授 )
(職稱: )
2012年11月12日
課題來(lái)源
本課題通過(guò)了解國(guó)內(nèi)外同類設(shè)備、查閱相關(guān)文獻(xiàn)資料,明確粉碎機(jī)的粉碎原理、工作過(guò)程和結(jié)構(gòu)特點(diǎn),同時(shí)參考企業(yè)的實(shí)際產(chǎn)品生產(chǎn)需求,設(shè)計(jì)高速渦流粉碎機(jī)。
科學(xué)依據(jù)(包括課題的科學(xué)意義;國(guó)內(nèi)外研究概況、水平和發(fā)展趨勢(shì);應(yīng)用前景等)
(1)課題科學(xué)意義
超細(xì)粉碎技術(shù)是伴隨現(xiàn)代高技術(shù)和新材料產(chǎn)業(yè)以及傳統(tǒng)產(chǎn)業(yè)技術(shù)進(jìn)步和資源綜合利用及深加工等發(fā)展起來(lái)的一項(xiàng)新的粉碎工程技術(shù)?,F(xiàn)已成為最重要的工礦物及其他原材料深加工技術(shù)之一,對(duì)現(xiàn)代高新技術(shù)產(chǎn)業(yè)的發(fā)展具有重要的意義。
(2)研究狀況及其發(fā)展前景
隨著高新技術(shù)和新材料產(chǎn)業(yè)的發(fā)展,實(shí)際生產(chǎn)對(duì)超細(xì)粉體產(chǎn)品粒度、純度及粒度分布等各項(xiàng)精度要求也相應(yīng)提高,同時(shí)又面臨著節(jié)約能源、保護(hù)自然環(huán)境等資源可持續(xù)性發(fā)展戰(zhàn)略的嚴(yán)峻挑戰(zhàn)。為滿足社會(huì)生產(chǎn)發(fā)展需要,今后超細(xì)粉碎技術(shù)的發(fā)展應(yīng)注重以下幾方面:
1) 改進(jìn)現(xiàn)有超細(xì)粉碎與精細(xì)分級(jí)設(shè)備。主要是在現(xiàn)有設(shè)備基礎(chǔ)上提高單機(jī)處理能力和降低單位產(chǎn)品能耗、磨耗,提高自動(dòng)控制水平。
2) 優(yōu)化工藝和完善配套。發(fā)展能滿足或適應(yīng)不同性質(zhì)物料,不同細(xì)度、級(jí)配和純度要求,具有不同生產(chǎn)能力的超細(xì)粉碎成套工藝設(shè)備生產(chǎn)線和生產(chǎn)技術(shù)。
3) 加強(qiáng)超細(xì)粉碎基礎(chǔ)理論的研究。在深入研究機(jī)械粉碎法技術(shù)的同時(shí),探尋化學(xué)合成法、物理法等其他非機(jī)械力超細(xì)粉碎技術(shù),以適應(yīng)不同特性物料對(duì)設(shè)備性能的具體要求 。
4) 完善、優(yōu)化超細(xì)粉碎設(shè)備和精細(xì)分級(jí)設(shè)備的配套。在現(xiàn)有超細(xì)粉碎設(shè)備基礎(chǔ)上,研制與之相配套的精細(xì)分級(jí)設(shè)備及產(chǎn)品輸送等其他輔助工藝設(shè)備,優(yōu)化超細(xì)粉碎設(shè)備和精細(xì)分級(jí)設(shè)備的配套組合工藝。
5) 尋求解決超細(xì)粉碎過(guò)程中磨損的有效途徑。研制高密度、高硬度研磨介質(zhì),解決設(shè)備磨損、部件的材質(zhì)問(wèn)題也應(yīng)是超細(xì)粉碎技術(shù)研究的重點(diǎn)。
在實(shí)際生產(chǎn)中,普通粉碎機(jī)存在能耗過(guò)大、效率較低,且易產(chǎn)生過(guò)熱粉碎等問(wèn)題,既影響了產(chǎn)品的質(zhì)量,又阻礙了粉碎原料的發(fā)展。而研究表明,高速渦流粉碎機(jī)是一種能耗少、粉碎能力大、結(jié)構(gòu)緊湊、無(wú)故障運(yùn)轉(zhuǎn)時(shí)間長(zhǎng)、清洗方便的高效粉碎設(shè)備,具有廣泛的應(yīng)用領(lǐng)域。
研究?jī)?nèi)容
1. 查閱相關(guān)文獻(xiàn),理解粉碎機(jī)的工作原理,整理翻譯相關(guān)外文資料;
2. 擬定粉碎機(jī)的設(shè)計(jì)方案;
3. 軸系結(jié)構(gòu)設(shè)計(jì),包括:
?。?)密封結(jié)構(gòu)設(shè)計(jì)
?。?)振動(dòng)分析
?。?)提高軸承的使用壽命
4. 用PRO/E軟件進(jìn)行造型設(shè)計(jì),三維裝配,并進(jìn)行運(yùn)動(dòng)仿真;
5. 設(shè)計(jì)繪制關(guān)鍵零部件及總裝配工程圖;
6. 撰寫(xiě)設(shè)計(jì)說(shuō)明書(shū),語(yǔ)言簡(jiǎn)潔、流暢、層次分明。
上機(jī)時(shí)數(shù)不少于200小時(shí),整個(gè)畢業(yè)設(shè)計(jì)過(guò)程的技術(shù)工作做到嚴(yán)謹(jǐn)細(xì)致、靈活、工作要有主動(dòng)性,計(jì)算方法、計(jì)算的程序、計(jì)算結(jié)果、結(jié)論要正確
擬采取的研究方法、技術(shù)路線、實(shí)驗(yàn)方案及可行性分析
(1) 研究方法
1. 查閱相關(guān)資料文獻(xiàn),了解粉碎機(jī)的原理、結(jié)構(gòu)、工作過(guò)程等;
2. FS高速渦流粉碎機(jī)的關(guān)鍵零部件有回轉(zhuǎn)主軸、分散器、葉輪、刀片等,本研究主要對(duì)主軸、刀片、進(jìn)料口,以及出料口刀片的排布等進(jìn)行分析;
3. 用PRO/E進(jìn)行三維建模,完成三維造型設(shè)計(jì);
4. 建模完成后進(jìn)行仿真,看運(yùn)動(dòng)是否與預(yù)期的效果一致。
(2) 技術(shù)路線
1. 通過(guò)網(wǎng)絡(luò)搜索、書(shū)籍查閱等途徑了解粉碎機(jī)的相關(guān)知識(shí);
2. 與指導(dǎo)老師交流,以達(dá)到最優(yōu)的解決方案;
3. 咨詢企業(yè)相關(guān)的技術(shù)人員,以求理論與實(shí)際相結(jié)合。
(3) 實(shí)驗(yàn)方案及可行性分析
對(duì)設(shè)計(jì)好的相關(guān)零件與實(shí)際生產(chǎn)的零件進(jìn)行比較,在投入生產(chǎn)中進(jìn)行改進(jìn),
以滿足市場(chǎng)的需求。
國(guó)外已有類似的產(chǎn)品設(shè)備,其工作原理已證明可行,技術(shù)成熟,故本設(shè)計(jì)具有可行性。
研究計(jì)劃及預(yù)期成果
研究計(jì)劃:
2012年11月12日-2012年11月27日:初步閱讀相關(guān)資料,完成開(kāi)題報(bào)告、外文翻譯、任務(wù)書(shū)等。
2012年11月28日-2012年12月25日:進(jìn)一步搜集相關(guān)文獻(xiàn)資料、工廠實(shí)習(xí)等,明確粉碎機(jī)工作原理、預(yù)期達(dá)到的性能指標(biāo)等,填寫(xiě)畢業(yè)實(shí)習(xí)報(bào)告。
2012年12月26日-2013年1月1日:擬定分析、確定總體設(shè)計(jì)方案,可行性分析。
2013年1月2日-2013年3月25日:結(jié)構(gòu)設(shè)計(jì)、參數(shù)選擇、強(qiáng)度校核、分析驗(yàn)證,優(yōu)化設(shè)計(jì),完成設(shè)計(jì)圖紙,三維裝配、動(dòng)態(tài)仿真。
2013年3月26日-2013年4月8日:撰寫(xiě)設(shè)計(jì)說(shuō)明書(shū)。
2013年4月9日-2013年4月15日:修改、完善,完成所有設(shè)計(jì)內(nèi)容。
2013年4月16日-2013年5月13日:畢業(yè)論文撰寫(xiě)和修改工作。
預(yù)期成果:
該設(shè)備設(shè)計(jì)完成后,能夠投入企業(yè)進(jìn)行生產(chǎn)
特色或創(chuàng)新之處
(1) Fs—400型高速渦流粉碎機(jī)結(jié)構(gòu)緊湊、加工方便,且震動(dòng)小,工作時(shí)間長(zhǎng),使用壽命長(zhǎng),生產(chǎn)效率高、安全性好、物料粉碎均勻。
(2)通過(guò)對(duì)該機(jī)的設(shè)計(jì),對(duì)更大型號(hào)的粉碎機(jī)的研究奠定了基礎(chǔ)。
已具備的條件和尚需解決的問(wèn)題
已具備的條件:
1. 粉碎機(jī)設(shè)計(jì)已有類似產(chǎn)品可供參考,各類資料比較齊全,查閱方便;
2. 已經(jīng)掌握高速渦流粉碎機(jī)的工作原理、粉碎過(guò)程,對(duì)粉碎機(jī)的結(jié)構(gòu)、運(yùn)動(dòng)方式已有了初步了解;
3. 具有運(yùn)用三維軟件的初步能力。
尚需解決的問(wèn)題:
1. 需要對(duì)具體的技術(shù)參數(shù)進(jìn)行分析和計(jì)算;
2. 明確零件之間的裝配要求、配合精度等;
3. 粉碎刀片間的間隙,軸承的壽命,粉碎腔體內(nèi)的密封等。
指導(dǎo)教師意見(jiàn)
指導(dǎo)教師簽名:
年 月 日
教研室(學(xué)科組、研究所)意見(jiàn)
教研室主任簽名:
年 月 日
系意見(jiàn)
主管領(lǐng)導(dǎo)簽名:
年 月 日
英文原文
Dispersion of nanoparticles by novel wet-type pulverizer utilized supersonic jet flow
Abstract.We have examined the dispersion of barium titanate nanoparticles (BT-NPs) and
have discussed the effect of air pressure supplied to the nozzle on the dispersion by using novel
wet-type pulverizer utilized supersonic jet flow (SSJM). The aggregated particle size was
decreased with increasing the air pressure and the collision times. In the optimized condition,
almost the BT-NPs were dispersed with the primary particles, however, further excessive
collision had caused reaggregations. The degree of dispersion has been affected by the air
pressure. The injected droplets had formed almost the same diameter regardless of air pressure
and the velocity was increased with increasing of the air pressure and reached 300 m/s. We
have speculated that the shockwave dominates the dispersion of BT-NPs.
1. Introduction
Nanoparticles are required highly in many applications such as dielectric materials for electronic
devices, electrode materials for secondary batteries, etc. The nanoparticles have been frequently
produced by the so-called build up processes such as hydrothermal process, coprecipitation process,and sol-gel method. For exploiting size effect of nanoparticles, it is crucial to control the dispersion and aggregation of the nanoparticles in suspension. However, nanoparticles aggregate more easily and strongly than submicron sized particles, and aggregated nanoparticles do not fragment easily.Therefore, it is quite difficult to disperse nanoparticles perfectly, and the dispersion of nanoparticles has become a fundamental technique for handling nanoparticles in industries. It has been reported that he nanoparticles were well-dispersed by using beads mill [1].
Bead milling with balls several tens of micrometers in diameter has recently been developed as a
new method to disperse nanoparticles to almost primary particle size [1]. However, the contamination caused by the grinded ball in bead milling was ten times higher than that caused by dry grinding [2].For providing nanoparticles dispersing method that can solve the above problem, we have developed novel wet-type pulverizer utilized supersonic jet flow (hereafter referred to as supersonic wet jet mill;SSJM). In this study, we have reported the dispersing result of barium titanate nanoparticles (BT-NPs) and have discussed the effect of air pressure on the dispersion by using the SSJM.
2. Experimental apparatus and procedure
2.1. Experimental apparatus
Figure1 shows schematic diagram of the SSJM (left). The right part of describes shows the internal configuration of the nozzle part. The compressed air (maximum air pressure was 0.6 MPa) was supplied at the top part of the nozzle. The Laval nozzle, which was used for the SSJM as shown in Figure1, is used to accelerate a compressed air passing through it to a supersonic speed, and upon expansion, to form the exhaust flow so that the heat energy propelling the flow is maximally converted into kinetic energy. As a result, the injected droplets passing through the nozzle were accelerated to supersonic and were naturally cooled. The suspension in the feed tank was supplied to the throat of the nozzle, while controlling the volume flow through the pump tubing. The supplied suspension had been formed droplets by jet flow and had been accelerated inside the nozzle. The accelerated droplets had collided with the SiC plate. Most of the processed suspension was collected at the bottom tank, and some of the processed suspension was evacuated along with the jet flow, therefore, the solvent recovery tank unit attached to the exhaust line.
Figure 1. Schematic diagrams of supersonic wet jet
mill (left) and the nozzle part (right), showing
approximate flow velocity (V), together with the
effect on temperature (T) and pressure (P).
2.2. Experimental procedure
Two kinds of BT-NP were used in this work. BT-NPs with the average particle size of 30 nm were
synthesized by the sol-gel method [3] (referred to as sol-gel BT). Commercially available BT-NPs
(BT-01, Sakai Chemical Industry, Japan) with the average particle size of 100 nm were manufactured by hydrothermal method (referred to as hydrothermal BT). A dispersant used in this study was an ammonium salt of poly (acrylic acid) (PAA-NH4+ , Mw 8000, Touagousei, Japan). The sol-gel BT was added to ethylene glycol monomethyl ether in 2 volume % (referred to as sol-gel BT suspension). PAA-NH4+ was added to distilled water in 5 wt% against powder weight and then the hydrothermal BT was added in 20 volume percents against distilled water (referred to as hydrothermal BT suspension). Each suspension was injected under various air pressures from 0.3 to 0.6 MPa. An aggregated particle size was evaluated by dynamic light scattering method (DLS, Nano-ZS, Malvern,UK). A shape and microstructure of the BT-NPs were examined with a transmission electron microscope (TEM, JEM-3200EX, JEOL, Japan) and a field emission scanning electron microscope (FESEM, S-4800, Hitachi, Japan).
For discussing the effect of air pressure on the dispersion by use of the SSJM, size and velocity distributions of droplets were measured as follows. Distilled water was injected under various air
pressures from 0.3 to 0.6 MPa. The size and velocity distribution of droplets at a distance of 100 mm away from the nozzle exit were measured simultaneously by Phase Doppler Anemometry (Dantec Dynamics, Denmark)
3. Result and discussion
Figure 2. Effect of collision number on cumulative
mean diameter of sol-gel BT
suspensions under various air pressures.
Figure 4. FESEM images of hydrothermal BT-
NPs: (A) and (B) were before collision process,
and (C) and (D) were after collision process for 3
times at 0.6 MPa
3.1. Dispersion of BT-NPs
Figure2 shows change of cumulative mean diameter DA, of which the value represents the
average aggregated size, with collision number under various air pressures for sol-gel BT.TEM images of BT-NPs collided under various conditions were shown in Figure3. DA of the BT-NPs collided at 0.3 MPa was decreased with increasing collision number. The BT-NPs collided for 3 times at 0.3 MPa were dispersed with almost the primary particles (as shown in Figure3(B)), however, further excessive collision had caused reaggregations. Although DA collided at 0.4 and 0.6 MPa were also decreased by the collision at once or twice, DA was increased immediately. As shown in Figure3 (D), sol-gel BT-NPs were pulverized to finer BT-NPs with the size under 10 nm than the initial particle size, and were formed aggregations with the size over 100nm consisted of the pulverized finer particles.
Figure4 shows FESEM images of the hydrothermal BT-NPs. As-recieved hydrothermal BT-NPs
were aggregated with the sizes over 1 μm as shown in Figure4 (A), and were widely distributed in range of from 100 to 200 nm and under 100 nm (Figure4 (B)). After the collision for 3 times at 0.6MPa, BT-NPs with the size under 100 nm were clearly increased and the aggregated particles were not existed as far as FESEM observation was concerned. Figure5 shows the hydrothermal BT particle size distributions collided at 0.3 MPa and 0.6 MPa. Like the FESEM observation, the aggregated particles were decreased and the particles with the size under 100 nm were increased with increasing collision number. However, reaggregations with the size over 1 μm and quite fine BT-NPs under 10 nm had been generated by the collision for 5 times at 0.6 MPa as shown in Figure5. Excessive collision at 0.6 MPa had caused reaggregations, similarly the sol-gel BT-NPs dispersion result. The degree of dispersion has been affected by air pressure.
3.2. Effect of air pressure on the dispersion by SSJM.
Figure 6 shows the size and the velocity distribution of injected droplets under the air pressures
from 0.3 to 0.6 MPa measured at a distance of 100 mm away from the nozzle exit. The injected
droplets formed almost the same diameter regardless of air pressure and the median diameter was
about 7 μm. The droplets velocity was increased with increasing of the air pressure and the velocity in all measurements reached 300 m/s. In case of dry-type jet mill, of which the pulverizing principal is similar to the SSJM, it has been reported that the driving force of pulverizing were the shockwave generated by the collision and the interparticle collision inside the nozzle [4].
Figure 5. Particle size distributions in hydrothermal BT suspensions collided at 0.3 MPa
(left) and 0.6 MPa (right).
For the SSJM, the shock wave has been occurred more strongly than that by using the conventional jet mill, of which the impact velocity is 80 m/s or less [5], since the shock wave is proportional to the impact velocity [4]. In addition, the cavitation and the shear stress can be generated [6], and the shear stress arisen from the deformation of droplet at the collision is also proportional to the impact velocity.Therefore, we have speculated that the shockwave and the shear stress arises from deformation of droplet dominate the dispersion of BT-NPs.
4. Conclusion
The BT-NPs collided at optimized condition were dispersed with almost the primary particle, however,further excessive collision had caused reaggregations. The BT-NPs collided at 0.6 MPa were pulverized to finer BT-NPs than the initial particle size, and were formed aggregations. The degree of dispersion has been affected by the air pressure. The injected droplets formed almost the same diameter regardless of air pressure, however, the velocity was increased with increasing of the air pressure and the velocity in all measurements reached 300 m/s. We have speculated that the
shockwave and the shear stress arises from deformation of droplet dominate the dispersion of BT-NPs.
References
[1] Inkyo M, Tahara T, Iwaki T, Okuyama K and Hogan C J 2006 J. Colloid Interface Sci. 304 535
[2] Nakayama T 2008 Kagakusouchi 50 88
[3] Makino T, Arimura M, Fujiyoshi K and Kuwabara M 2007 Key Eng. Mater. 350 31
[4] Okuda S 1999 J. Soc. Powder Technol. Jpn. 36 558
[5] Shakouchu T and Morimoto H 2004 J. Jpn. Soc. Experimental Mechanics 4 184
[6] Rein M 2002 Drop-Surface Interactions, Springer, New York
中文譯文
利用超音速射流分散納米粒子的新型濕式粉碎機(jī)
概要
我們已經(jīng)檢查并且探討了分散納米鈦酸鋇(BT-NPS)的技術(shù)和實(shí)驗(yàn)過(guò)程,在這其中通過(guò)使用新穎的超音速射流(SSJM)新型濕式粉碎機(jī)上的分散體上的噴嘴,討論、研究出了空氣壓力對(duì)其的影響。本次研究的這款新型濕式粉碎,是機(jī)利用超音速射流(SSJM),粉碎納米粒子的。初步得出聚合粒子的大小與空氣壓力和碰撞時(shí)間的關(guān)系,得出其隨后兩者的增加而相應(yīng)的增加。在實(shí)驗(yàn)過(guò)程中,在優(yōu)化條件下,BT-納米顆粒幾乎與初級(jí)粒子一樣分散離合。但是,經(jīng)過(guò)一段時(shí)間的進(jìn)一步碰撞,最終的過(guò)度碰撞造成了物質(zhì)間的相互重新組合。這種擠壓破壞、重新聚合的現(xiàn)象以及分散程度受到空氣壓力的影響。注入的液滴形成了直徑幾乎相同的形狀,速度隨著空氣壓力的增加而增加,最終增加到了300m/。通過(guò)此類現(xiàn)象的研究,我們紛紛猜測(cè),在引起這些一些列的現(xiàn)象中,沖擊波在BT-粒子的分散中占據(jù)了主導(dǎo)地位,起到了推波助瀾的作用。
1. 介紹
納米粒子(粒度在1—100nm之間的粒子,又稱超細(xì)微粒 ),被廣泛的應(yīng)用到許多場(chǎng)合,比如電子設(shè)備中使用的高介電材料,二級(jí)電池電極材料等,納米顆粒已被頻繁的建立和使用在所謂的“建立進(jìn)程”,例如水熱法,共沉淀法,溶膠-凝膠法生產(chǎn)的納米顆粒等。想要利用納米粒子的尺寸效應(yīng)[1],關(guān)鍵的部分是要控制在懸浮液中的納米顆粒的分散性和懸浮聚合程度。然而,納米粒子聚合相比亞微米大小的顆粒,更容易并且可以劇烈的發(fā)生反應(yīng),聚合納米顆粒并不很容易破碎或裂開(kāi)。因此,很大程度上來(lái)說(shuō),分散納米粒子是相當(dāng)困難和復(fù)雜的技術(shù)。同時(shí),完全分散納米粒子,已成為處理納米粒子行業(yè)中的一個(gè)基本技術(shù)。據(jù)報(bào)道,其中的一個(gè)說(shuō)法是,利用納米粒子良好的分散性能,通過(guò)使用有孔玻璃珠磨機(jī)[1],最近已經(jīng)發(fā)展出一個(gè)可以利用珠磨分散納米顆粒珠銑出球直徑幾十微米的超小尺寸的新方法[1]。然而,這項(xiàng)發(fā)現(xiàn)的背后還引發(fā)了一系列的問(wèn)題,其中就包括珠磨機(jī)中研磨球所造成的污染,是干摩機(jī)引起污染的10倍以上。通過(guò)這一系列的問(wèn)題以及尋求解決之道的途徑,結(jié)合在此過(guò)程中,對(duì)納米顆粒分散方法所進(jìn)行的一些研究和其中的發(fā)現(xiàn),我們已經(jīng)開(kāi)發(fā)出新穎的濕式粉碎機(jī)。這種新型粉碎機(jī)是利用超音速噴流(以下稱為超音速濕式噴射研磨機(jī);SSJM)來(lái)實(shí)現(xiàn)粉碎效果。在這項(xiàng)研究中,我們已經(jīng)報(bào)道了鈦酸鋇納米粒子(BT-納米顆粒)的分散的結(jié)果,并通過(guò)使用SSJM分散,討論了空氣壓力的影響效果。
2. 實(shí)驗(yàn)儀器和程序
2.1 實(shí)驗(yàn)裝置
如圖1,顯示出來(lái)SSJM(左)的示意原理圖。右邊的部分顯示描述了內(nèi)部配置部分的噴嘴部分的內(nèi)部結(jié)構(gòu)。在頂端部分的噴嘴供給壓縮空氣(最大空氣壓力為0.6MPa)。這個(gè)噴嘴(拉伐爾噴嘴),如圖1所示,用于SSJM,頂部的壓縮空氣通過(guò)它來(lái)加速,獲得一個(gè)超音速加速,并在膨脹時(shí),形成的排氣流,以便能最大限度地推動(dòng)熱能轉(zhuǎn)換成動(dòng)能。其結(jié)果是,通過(guò)噴嘴注入的液滴被加速到超音速和進(jìn)行自然冷卻。與此同時(shí),在進(jìn)料罐中的懸浮液被供給到所述噴嘴的喉部,從而起到控制流過(guò)泵管的體積流量的作用。所提供的懸架已經(jīng)在噴嘴內(nèi)部得到加速并且同時(shí)形成了液滴的噴射流。加速液滴與碳化硅板相互碰撞。處理后的懸浮液大部分都被收集在底部的收集罐,一些處理后的懸浮液隨著噴流被抽空疏散,因此,溶劑回收罐裝置,其被連接到排氣管。
圖1 超音速濕式噴射示意圖
在磨機(jī)(左)和噴嘴部分(右)表示出
了大約的血流速度(V),連同
溫度(T)和壓力(P)的影響。
2.2 實(shí)驗(yàn)過(guò)程
在這項(xiàng)實(shí)驗(yàn)工作中,使用的是兩種不同類型的BT-NP。 BT-納米粒子與平均粒徑為30nm的通過(guò)溶膠-凝膠法合成(簡(jiǎn)稱為溶膠-凝膠BT)。市售的BT納米粒[3](BT-01,堺化學(xué)工業(yè),日本)制造的平均粒徑為100nm,采用水熱法(簡(jiǎn)稱為熱液BT)。本研究中使用的分散劑是一種聚(丙烯酸)(PAA-NH4 +,分子量8000,Touagousei,日本)的銨鹽。溶膠-凝膠BT具體過(guò)程是在其中加入乙二醇單甲基醚2%(體積)(以下簡(jiǎn)稱為溶膠-凝膠BT懸浮液), PAA-NH4 +的溶液中加入蒸餾水,再兌粉末重量的5%(重量),然后兌蒸餾水(簡(jiǎn)稱作為熱液BT懸浮)在20%(體積)溶液中加入熱液BT。每個(gè)注射懸浮液根據(jù)不同的空氣壓力范圍從0.3?0.6兆帕。一個(gè)聚合粒子的大小具體是通過(guò)動(dòng)態(tài)光散射法(DLS,納米-ZS,馬爾文,英國(guó))來(lái)進(jìn)行判定和評(píng)價(jià)的。通過(guò)使用透射電子顯微鏡(TEM,JEM-3200EX,JEOL,日本)和電場(chǎng)發(fā)射掃描顯微鏡(SEM,S-4800,日立公司,日本)對(duì)BT-納米顆粒的形狀和微觀結(jié)構(gòu)進(jìn)行了深入的觀察和研究。為了討論以上的分散液中的空氣壓力的效果,通過(guò)使用本SSJM,對(duì)液滴的尺寸和速度分布進(jìn)行了如下進(jìn)行測(cè)定。具體過(guò)程是將蒸餾水注入壓力為0.3?0.6兆帕的空氣壓力下,噴嘴出口的距離相差100毫米的液滴,對(duì)其大小和速度分布進(jìn)行測(cè)定,同時(shí)測(cè)量相位多普勒風(fēng)速儀(丹特克動(dòng)力,丹麥),觀察具體讀數(shù)和實(shí)驗(yàn)現(xiàn)象。
3. 結(jié)果與討論
圖2 累積平均直徑為溶膠-凝膠BT碰撞數(shù)的影響
不同的空氣壓力下的懸浮液。
圖4 FESEM圖像熱液BT-NPS:(
A)和(B)之前的碰撞過(guò)程,和(C)和(D)3后碰撞過(guò)程
時(shí)間在0.6 MPa
3.1 BT-粒子的分散
如圖2,給出了累積平均變化關(guān)系示意圖,其中的數(shù)值代表直徑DA,它的值代表平均聚集規(guī)模。碰撞數(shù)根據(jù)不同的空氣壓力,表現(xiàn)為為溶膠-凝膠的BT.TEM圖像的BT-NPS相撞了各種條件如下圖所示。 DA BT-粒子的相撞增加碰撞數(shù)下降0.3兆帕。對(duì)BT-納米粒子相撞,每次幾乎粒子分散在0.3 MPa的3倍(如圖3(B)所示),然而,進(jìn)一步的過(guò)度碰撞造成reaggregations,。雖然DA相撞0.4和0.6兆帕,也減少了一次或兩次的碰撞,DA立即升高。如圖3(D)所示,溶膠-凝膠BT-納米粒子粉碎成更細(xì)的BT-納米粒子,BT-納米粒子的大小比初始顆粒尺寸為10nm以下,形成聚合的大小超過(guò)100nm的包括粉碎的更細(xì)的顆粒。圖4-1顯示FESEM圖像的熱液BT粒子。 AS-收件熱液BT納米粒子連同超過(guò)1微米的大小,如圖4(A)所示,并廣泛的分布,其范圍從100至200 nm和100 nm以下(如圖4(B))。撞船事件發(fā)生后的3倍,在0.6MPA,BT-NPS的大小在100 nm以下明顯增多,凝集顆粒不存在,肉眼已經(jīng)無(wú)法直觀觀察,盡可能通過(guò)FESEM觀察。如圖5-1所表示出的是水熱BT顆粒大小分布在0.3 MPa和0.6 MPa的相撞。我們通過(guò)FESEM觀察,發(fā)現(xiàn)凝集粒子下降,在100 nm以下的粒子的大小的增加而增加碰撞數(shù)。然而,已超過(guò)1微米的大小相當(dāng)精細(xì)BT-NPS在10納米重新組合碰撞所產(chǎn)生的5倍,在0.6 MPa,如圖5-1所示。在0.6 MPa造成了過(guò)多的碰撞的重新組合,同樣的溶膠-凝膠BT-納米顆粒分散體的結(jié)果。已經(jīng)受到氣壓的分散程度的不同程度的影響。
3.2 由SSJM分散體的空氣壓力的影響。
如圖6表示出的是根據(jù)空氣的壓力的大小和噴射的液滴的速度分布關(guān)系圖,從0.3到0.6 MPa的測(cè)量是在相差的在噴嘴出口的距離為100毫米。注入形成的液滴直徑幾乎相同,與空氣壓力無(wú)關(guān),中值粒徑為約7微米。的微滴的??速度的增加而增加,在所有測(cè)量的過(guò)程中,空氣壓力和速度達(dá)到300米/秒。在干式噴射式粉碎機(jī)中,其中粉碎主要是的SSJM類似的情況下,它已被報(bào)道,干式噴射式粉碎機(jī)的粉碎的驅(qū)動(dòng)力是由碰撞產(chǎn)生的沖擊波和顆粒間的碰撞所產(chǎn)生的,在噴嘴內(nèi)[4]。
圖5 熱液BT懸浮的顆粒大小分布在0.3 MPa相撞(左)
和0.6兆帕(右)。
對(duì)于SSJM,相比以往的噴射式粉碎機(jī),沖擊波發(fā)生更強(qiáng)烈的作用力,沖擊速度為80米/秒或更少[5],由此可以看出,沖擊波的強(qiáng)烈程度和沖擊速度成正比[4] 。此外,氣蝕和剪切應(yīng)力可產(chǎn)生[6],從液滴碰撞的變形所產(chǎn)生的剪切應(yīng)力也成比例的的影響velocity.Therefore的,據(jù)此我們推測(cè),沖擊波產(chǎn)生的剪切應(yīng)力從液滴變形主宰BT-納米粒子的分散性。
4. 結(jié)論
BT粒子相撞產(chǎn)生的現(xiàn)象和結(jié)果,在優(yōu)化的條件下,幾乎與初級(jí)粒子分散產(chǎn)生的現(xiàn)象和結(jié)果一致,然而,過(guò)多的碰撞造成重聚合。 BT粒子相撞粉碎較細(xì)BT-NPS 0.6兆帕比初始粒徑,形成聚合。受到的空氣壓力的分散程度。注入的液滴形成直徑幾乎相同,與所處的空氣壓力的大小無(wú)關(guān),但是,其直徑的大小隨速度的增加而增加,達(dá)到300米/秒的所有測(cè)量中的空氣壓力和速度。我們紛紛猜測(cè),沖擊波產(chǎn)生的剪切應(yīng)力變形液滴主宰BT-納米粒子的分散性。
參考文獻(xiàn)
[1] Inkyo M, Tahara T, Iwaki T, Okuyama K and Hogan C J 2006 J. Colloid Interface Sci. 304 535
[2] Nakayama T 2008 Kagakusouchi 50 88
[3] Makino T, Arimura M, Fujiyoshi K and Kuwabara M 2007 Key Eng. Mater. 350 31
[4] Okuda S 1999 J. Soc. Powder Technol. Jpn. 36 558
[5] Shakouchu T and Morimoto H 2004 J. Jpn. Soc. Experimental Mechanics 4 184
[6] Rein M 2002 Drop-Surface Interactions, Springer, New York
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