本文選題：PTFE覆膜濾料　切入點(diǎn)：環(huán)境濕度　出處：《北京化工大學(xué)》2015年碩士論文

【摘要】：燃煤電廠等行業(yè)排放的粉塵尤其是PM2.5對(duì)環(huán)境及人類健康產(chǎn)生極大的負(fù)面影響,采用覆膜濾料作為過濾材質(zhì)的袋式除塵技術(shù)可實(shí)現(xiàn)對(duì)PM2.5的高效捕集。濾餅過濾阻力是影響袋式除塵能耗的重要原因,它主要取決于濾餅結(jié)構(gòu)。空隙率是影響濾餅結(jié)構(gòu)的重要參數(shù),它與顆粒間作用力以及顆粒性質(zhì)密切相關(guān)。煙氣的脫硫脫硝等工藝會(huì)帶入-定量的水,并隨著溫度的改變而影響煙氣濕度,而濕度則會(huì)影響顆粒間作用力進(jìn)而影響濾餅結(jié)構(gòu)。因此研究濕度對(duì)顆粒間作用力及除塵性能的影響將對(duì)節(jié)約袋式除塵能耗有著重要意義。除了濕度濾餅空隙率還受顆粒性質(zhì)的影響。粒徑是描述顆粒的最基本參數(shù),即使同一種顆粒粒徑也會(huì)有較大差異。因此,研究顆粒粒徑在不同環(huán)境濕度下對(duì)顆粒堆積行為的影響將具有實(shí)際意義。本文設(shè)計(jì)并搭建了一套環(huán)境濕度可控且長(zhǎng)期穩(wěn)定的實(shí)驗(yàn)裝置。從絕對(duì)濕度和相對(duì)濕度兩方面入手,通過測(cè)定顆粒群坍塌角考察了濕度對(duì)顆粒間作用力的影響；并采用PTFE覆膜濾料作為過濾材質(zhì),研究了環(huán)境濕度對(duì)濾餅過濾阻力、濾餅空隙率以及荷塵量的影響；并在此基礎(chǔ)上研究了顆粒粒徑在不同環(huán)境濕度下對(duì)除塵性能的影響。不同環(huán)境濕度下的滑石粉顆粒坍塌角實(shí)驗(yàn)表明：(1)顆粒間作用力隨環(huán)境濕度的提高呈線性增長(zhǎng)；與相對(duì)濕度低于100%時(shí)相比,空氣飽和(相對(duì)濕度100%)時(shí)顆粒間粘附力隨濕度增長(zhǎng)更為迅速。(2)PTFE膜在高環(huán)境濕度下具有良好的清灰性能,這為其在高環(huán)境濕度下應(yīng)用于袋式除塵提供了可能。過濾實(shí)驗(yàn)結(jié)果表明：(1)在濾料及氣體固定的情況下,濾餅壓降ΔPc可以看作是粉塵濃度c、表面過濾流速Vs、過濾時(shí)間,、濾餅空隙率ε和顆粒粒徑dp的函數(shù)。其中c和t是獨(dú)立變量,環(huán)境濕度、Vs、dp均影響ε。(2)環(huán)境濕度增大,顆粒間作用力增強(qiáng),顆粒堆積更為疏松,濾餅空隙率提高,濾餅過濾阻力明顯降低,有效延長(zhǎng)了單次過濾周期,提高了荷塵量。對(duì)于1250目滑石粉,當(dāng)環(huán)境濕度從0.0028g/g干氣(粉塵密度為19.62g/m3)提高到0.0414g/g干氣(粉塵密度為30.91g/m3)時(shí),單次過濾周期從609s提高到5634s。但環(huán)境濕度對(duì)除塵性能的強(qiáng)化作用存在一個(gè)最優(yōu)值,一旦超過這個(gè)值,強(qiáng)化作用開始減弱,甚至導(dǎo)致除塵性能惡化。(3)顆粒粒徑越小,過濾阻力越高,濾餅阻力增長(zhǎng)速率隨環(huán)境濕度下降越快,說明小顆粒粒徑的除塵性能對(duì)環(huán)境濕度響應(yīng)更敏感。
[Abstract]:The dust emission from coal-fired power plants and other industries, especially PM2.5, has a great negative impact on the environment and human health. The bag dust removal technology using membrane coated filter material as filter material can realize the high efficiency capture of PM2.5. Filter resistance of filter cake is the important reason that affects the energy consumption of bag dust removal. It mainly depends on the structure of filter cake. Porosity is an important parameter affecting the structure of filter cake, which is closely related to the interaction between particles and the properties of particles. And with the change of temperature, the humidity of flue gas is affected. Therefore, the study of the effect of humidity on the interparticle force and dust removal performance will be of great significance in saving energy consumption of bag dust removal, in addition to the void rate of filter cake with humidity, it is very important to study the effect of humidity on the interparticle force and dust removal performance of filter cake. The particle size is the most basic parameter to describe the particle. Even the same particle size varies greatly. It will be of practical significance to study the effect of particle size on particle accumulation behavior under different environmental humidity. In this paper, a set of experimental equipment with controllable and stable environmental humidity is designed and built. The effect of humidity on intergranular force was investigated by measuring the collapse angle of particle group, and the effect of environmental humidity on filter resistance, porosity and dust loading of filter cake was studied by using PTFE membrane filter material as filter material. On the basis of this, the effect of particle size on dust removal performance was studied under different environmental humidity. The experimental results of collapse angle of talc particles under different ambient humidity showed that the interaction force between particles increased linearly with the increase of environmental humidity. When air saturation (RH) is 100, the adhesion between particles increases more rapidly than when RH is lower than 100. The PTFE film has good ash removal performance under high ambient humidity. This makes it possible to apply it to bag dust removal at high ambient humidity. The filtration experiment results show that: 1) when the filter material and gas are fixed, The filter cake pressure drop 螖 Pc can be regarded as a function of dust concentration, surface filtration velocity, filtration time, cake porosity 蔚 and particle diameter DP, where c and t are independent variables, and the environmental humidity (VsN dp) affects the increase of ambient humidity. With the increase of intergranular force, the accumulation of particles is more loose, the porosity of filter cake is increased, the filter resistance of filter cake is obviously reduced, the single filtration period is effectively prolonged and the amount of dust charged is increased. For 1250 mesh talcum powder, When the ambient humidity was increased from 0.0028g/g dry gas (dust density 19.62g / m 3) to 0.0414g/g dry gas (dust density 30.91g / m 3), the single filter cycle increased from 609s to 5634s. The strengthening effect began to weaken, even leading to the deterioration of dust removal performance. The smaller the particle size, the higher the filtration resistance, and the faster the increase rate of cake resistance with the environmental humidity, indicating that the dust removal performance of the small particle size is more sensitive to the environmental humidity response.
【學(xué)位授予單位】：北京化工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：X773;TQ028.8

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本文編號(hào)：1668985