Washing Equipment For Aspen Alcell

Auto-catalyzed ethanol pulping existed a phenomenon that during the washing process, when the volume fraction of ethanol was reduced or washing temperature was lower, there would be a substantial of ethanol lignin adsorb on the surface of the fiber. It leaded to that the quality of pulp was reduced and the amount of subsequent bleaching chemicals was increased. General approach to solve this issue was washing the pulp by ethanol solution in high temperature (the temperature at about60℃, the volume fraction of ethanol aqueous solution is about60%)countercurrent washing. Laboratory adopts manual washing, with much ethanol volatilizing, it is so easy to cause burning and a large number of ethanol waste. At the same time it also greatly increased the ethanol recycle burden. If a washing equipment of the auto-catalyzed ethanol pulping designed to deal with the issue, realize the mechanical washing, prevent ethanol volatilization, and realize automatic backwashing, it will not only save labor and cost,but also have certain guidance and reference significance to ethanol pulping method implementation industrialization.This topic is a part of the national natural science fund project "aspen wood auto-catalyzed ethanol pulping of lignin in fibre micro zone migration and the mechanism of surface adsorption studies"(31170554/c160402). The purpose of it is to design an washing equipment to implement in the laboratory about the automatic washing of auto-catalyzed ethanol pulpFirst, aspen wood from the auto-catalyzed ethanol pulping was washed in the laboratory,followed by unwashed and washed pulp surface were observed by scan electron microscope to view the lignin adsorption conditions, and results showed that the water can make kappa number fall from90to75.5, washing down little lignin, most still adsorbed on the surface of lignin lignin.Second, auto-catalyzed aspen wood ethanol pulp was submitted to ethanol aqueous solution manual washing experiment in the laboratory, in the liquor ratio is1:20, three single period of washing conditions, then respectively investigate on the ethanol concentration and washing temperature condition experiment, examing kappa number change, using electron microscope, achieving the better washing conditions(ethanol concentration is60%, temperature is60℃) at which kappa number is21.6which is considered ideal. This condition lay the basis of the design of the ethanol automaticed washing equipment.With the idea that waste liquid after washing can be recycled, according to the result of washing conditions of laboratory data,now a design of ethanol pulp semiautomatic four countercurrent pulp washing equipment is done, to achieve the ethanol pulp machine washing in the laboratory. At the same time, the result pH of the pulp after cooking is around3, temperature is little higher, and waste water and60%ethanol solution is corrosive, so the equipment material selection is anticorrosive and main jar parts adopt stainless steel. Line equiped with national standard PVC pipe. Pump Choose national standard acid-resistant one. In addition, considering the ethanol is volatile and needs appropriate heating, the whole washing process must be closed state, namely the device belongs to the pressure vessel. According to this concept, the process and the equipment detailed drawingswere designed.Based on GB150, GB151steel pressure vessel manufacture and design standards, the main part of tank wall thickness is2mm after a calculation. Based on the lab manual washing pulp oven-dry value,liquid ratio and time, the actual parameters of acid-resistant pump is Q=72(1/h), h=2(m), N=33(w) after calculating. The data, flow chart and detail drowings above act as the basis of equipment manufacturing. At the same time it is the equipment operation explanation.