| In recent years,the form of livestock and poultry houses in China has developed from the traditional open type to the closed type.Although the closed type enclosure improves the controllability of the environment and provides relatively stable environmental conditions for the growth of livestock and poultry,the closed type enclosure structure also weakens the mobility of the air in the enclosure to a certain extent,which is easy to cause the deterioration of the air quality in the enclosure,especially in winter in northern China In order to reduce the adverse effects of water vapor and odor on livestock and poultry,it is necessary to consider not only the heat preservation but also the humidity and odor reduction.The regulation of air environment in livestock and poultry houses has become an important part of healthy breeding.Acetate fiber has good characteristics of particle filtration and gas adsorption,and is widely used in cigarette filter,clothing and other fields.Among them,due to the strict requirements of cigarette production process,a large number of waste acetate fiber and residual filter rods are produced every year.At present,the waste acetate fiber and residual filter rods are mainly used as industrial solid wastes for incineration and landfill treatment,resulting in a huge waste of resources.Using the good particle filtration and adsorption characteristics of waste acetate fiber and the principle of refrigeration dehumidification,the design of ammonia dehumidification device not only solved the problem of deodorization and dehumidification of air in livestock and poultry houses,but also found a new way to use acetate fiber.In this paper,waste acetate fiber from cigarette was used as raw material to prepare acetate fiber filter cloth by felt making and hot pressing,which was used to remove odor in livestock and poultry house.The morphology,crystallinity,thermal properties,moisture absorption and ammonia adsorption properties of tow like fibers in acetate fiber waste were studied.The acetate fiber filter cloth was prepared by needling non-woven process,and the hot pressing process was used to improve the quality of acetate fiber The mechanical properties of non-woven fabric,the best mechanical properties of the process;through response surface analysis to get the best adsorption process;explore the different concentrations of potassium hydroxide solution and hydrochloric acid solution treatment on the performance of acetate fiber hot press filter cloth;based on the adsorption characteristics and refrigeration dehumidification characteristics of formed acetate fiber filter cloth,design the deodorization and dehumidification device,and optimize the process It is necessary to study and discuss.The experimental results show that:(1)The surface of waste acetate fiber is smooth and the width difference is not significant.There may be a small amount of glycerin acetate particles on some fibers.The crystallinity of waste acetate fiber is 59.09%,the glass conversion temperature is 200.85℃,the moisture return rate is 5.91%.When the ammonia concentration is 40ppm～80ppm,the removal rate of ammonia is about 50%.(2)The results show that the average thickness of the filter cloth is 2.00mm,the transverse breaking strength is 40.35N,the gram weight is 155.41g/m2,and it has good mechanical properties;the best technological conditions for improving the mechanical properties of the filter cloth are as follows:hot pressing temperature 140℃～150℃,hot pressing pressure 15KPa～17.5KPa,hot pressing time 30min～40min。(3)Taking hot pressing temperature,hot pressing pressure and hot pressing time as variables,the influence of hot pressing process on ammonia adsorption performance of vinegar fiber filter cloth was studied.The response surface test results showed that the influence of various factors on ammonia adsorption rate was as follows:hot pressing temperature>hot pressing pressure>hot pressing time.The optimal molding process parameters were hot pressing temperature 146 ℃,hot pressing pressure 12.5KPa and hot pressing time 35min The maximum average adsorption rate of ammonia was 68.73%.(4)The effect of hydrochloric acid and potassium hydroxide treatment on the adsorption performance of hot pressed cellulose acetate filter cloth was studied.The corrosion ability of hydrochloric acid on the surface structure of cellulose acetate is greater than that of potassium hydroxide.High concentration of hydrochloric acid can oxidize the surface of cellulose acetate;When the reaction time is more than 150min,the transverse fracture strength tends to be stable,and the minimum fracture strength is close to 37.5N.under the same reaction time,the minimum fracture strength of potassium hydroxide is 60.64N of 5mol/L and 180min;When the concentration of hydrochloric acid is 0.2mol/L,the adsorption effect is the best.When the concentration of ammonia is 30min～120min,the concentration of ammonia decreases from 21.6ppm to 15.7ppm in 120min with the increase of hydrochloric acid treatment time.However,compared with the untreated cellulose acetate non-woven fabric,the adsorption effect of potassium hydroxide treated filter cloth on ammonia has no obvious change,Although the mechanical properties of cellulose acetate filter cloth were changed by hydrochloric acid and potassium hydroxide modification,there was no significant effect on the adsorption effect.Therefore,acid-base modification is not a part of non-woven process,but it can be considered as one of the means to decompose acetate fiber.(5)Based on the adsorption effect of acetate fiber filter cloth on ammonia and the principle of cooling and dehumidification,a deodorization and dehumidification device was designed,and semiconductor refrigeration.was selected as the air cooling source.The deodorization and dehumidification device is composed of ventilating fan,filter,dehumidifier,interceptor,ultraviolet lamp and air duct.The cross-sectional area of hot pressing filter cloth is 81cm2，the weight is,single-layer setting，semiconductor refrigeration power is 100W,the design flow velocity is 0.38～0.49m/s,and the total power of the device is 150W.The operation results show that:the acetate fiber filter cloth has a certain removal effect on ammonia,but its adsorption capacity has a certain capacity requirements.With the extension of adsorption time,the fiber will lose the removal of ammonia when it is nearly saturated;under the designed flow velocity,the ammonia concentration through the air stream begins to decline from 60ppm,and it drops to 23.7ppm after 90min,and the ammonia concentration is reduced to 23.7ppm The removal rate was 62.2%.Then,with the prolongation of ventilation time,the ammonia concentration in the air flow increased,and it was close to the inlet concentration at 180 min,at which time the acetate fiber lost its adsorption and purification capacity for ammonia.(6)Acetate fiber hot press filter cloth has a certain adsorption effect on low concentration ammonia.The ammonia removal and dehumidification device based on acetate fiber filter cloth has a certain removal ability for low concentration ammonia and high concentration humidity in a space range,which can be used as a form of aquaculture ammonia removal and dehumidification pretreatment. |
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