Engineering Technology Exploration Of Wastepaper Repulping Energy-saving

This article makes a research on the methods of achieving the wastepaperrepulping energy saving. First, energy saving improvement techniques of differentpulping equipments were analyzed; Second, using OCC as a raw material in thetest,the effect of different parameters on the wastepaper repulping was researched andrepulping parameters was optimized. Finally, we add different kinds of repulpingaddictive to improve the efficiency of de flaking and the performance of slurry.In the test, using OCC as a raw material and adopting ordinary low-thickpulper as a pulping equipment., we researched the effect of pretreatment time,,repulping consistency, temperature, rotor speed,repulping time on the wastepaperrepulping. The results show that pretreatment of OCC, improving the repulpingconsistency, temperature, rotor speed and prolonging the repulping time all canimprove the degree of deflaking of wastepaper.Repulping time is the main factor.Repulping30seconds can achieve a good deflaking effect, but a decrease of pulpperformance. In consideration,to get low flake contents,low energy-consuming anda good repulping effect, the comparatively good repulping parameters is: waterpretreatment OCC2h,4%repulping consistency, first gear rotor speed, repulpingtemperature20℃。The effect of three kinds of different surfactant on the wastepaper repulping wasstudied. The results show that adding six different surfactant can increase deflaking ofOCC to different degrees. Among, OCC adding1%dosage LAS is more obvious.prolonging the pretreatment time and improving temperature can increase the degreeof de flaking further, but limited. We concluded that adding LAS optimized by theorthogonal experiment the best repulping process as follows: wastepaper20g(ovendry), repulping consistency of4%, first gear rotor speed, pretreatment time1.5h,repulping temperature50℃、LAS dosage of0.2%,repulping time60s.The final flakecontent is1.2%. We researched NaOH、Na2CO3、Na2SiO3chemical pretreatment effect ondeflaking of waste paper The result showed that Alkaline hot pretreatment cansignificantly increase the degree of deflaking of waste paper. The range ofincreasement of NaOH is higher than Na2CO3and Na2SiO3. Na2SiO3pretreatment hasa better result. At the same time, comparing surfactant and Na2SiO3pretreatmenteffect on the properties of OCC pulp with blank sample. Beating degree, distributionof fiber’ length was measured and the physical shape of fiber was observed. It turnedout that adding LAS and Na2SiO3pulp slurry quality has improved,but the filteringperformance declined.