Blending Ratio Analysis of Akund / Cotton Blended Yarn Based on Micro Projection

A microscope method was developed for testing the blending ratio of akund/cotton blended yarns. Fiber characteristics such as diameter, longitudinal feature, and hollow structure were observed to identify akund and cotton. Therefore, the measurement of the blending ratio for akund/cotton blended yarns based on each fiber's amount, moisture regain, and metric count was available. The results show that using specimen's longitudinal section is more effective during the fiber counting than specimen's transverse section benefiting from the separation of the fibers.

Investigation of the Effects of a Large Percentage of Dried Sludge on the Operation of a Coal-Fired Boiler

A 600 MW coal-fired boiler with a four-corner tangential combustion mode is considered here to study the combustion features and pollutant emissions at different loads for large-percentages of blending dried sludges.The influence of the over-fired air(OFA)coefficient is examined and the impact of the blending ratio on the boiler operation is explored.The results show that for low blending ratios,a slight increase in the blending ratio can improve the combustion of bituminite,whereas a further increase leads to the deterioration of the combustion of blended fuels and thus reduces the boiler efficiency.Enhancing the supporting capability of the secondary air effectively reduces the slagging degree in the bottom ash hopper and improves the burnout rate of coals.For a large-percentage blending case at full load,it is found that the OFA coefficient must be reduced appropriately,otherwise,a secondary high-temperature combustion zone can be generated in the vicinity of the furnace arches,causing high temperature slagging and superheater tube bursting.Considering the influences of combustion and pollutant emissions,the recommended OFA coefficient is 0.2.Blending dried sludge under low loads increases the flue gas temperature at the furnace exit.While reducing the flue gas temperature in the main combustion region,which is beneficial to the safe operation of the denitrification system.Increasing the blending ratio and reducing load lead to an increase in NOx concentration at the furnace exit Sludges with low nitrogen content are suggested for the practical operation of boilers.

Effects of Blending Ratio on Combustion and NO Emission Characteristics during Co-Firing of Semi-Char and Lignite in a 350 kW Pulverized Coal-Fired Furnace

The influence of the blending ratio of pyrolyzed semi-char(SC)on the ignition,NO emission and burnout characteristics of lignite co-fired with SC was investigated in a 350 kW fuel-rich/lean combustion furnace.The flame temperature and concentrations of gaseous species including O_(2),CO,and NO,were measured in detail.The results indicated that the ignition characteristics of the blended fuel worsened with increasing SC blending ratio,such as an elongated ignition standoff distance.The addition of SC to lignite delayed the appearance of a stable flame boundary,and the stable combustion zone moved down,but the final combustion stability was gradually strengthened in the later combustion stage.NO emission concentration at the primary combustion zone(PCZ)outlet was the lowest at 472.6 mg/m^(3)@6%O_(2)when the SC blending ratio was 25%.The combustion zone and reducing zone areas in PCZ were defined to evaluate the NO reduction characteristics,and quantitative analysis using a multiple linear regression model showed that heterogeneous reduction was more important than homogeneous reduction in lowering NO emissions.The Raman spectrum of the char sample indicated that the addition of lignite promoted the formation of small aromatic rings in the early ignition stage,corresponding to a higher char reactivity.The burnout ratio of pure lignite was maximal and was decreased by increasing the SC blending ratio.Synthetically,considering the ignition standoff distance,NO emission,and burnout ratio,the optimum SC blending ratio was estimated to be 25%.

Effects of pyrolyzed semi-char blend ratio on coal combustion and pollution emission in a 0.35 MW pulverized coal-fired furnace

The effects of blend ratio on combustion and pollution emission characteristics for co-combustion of Shenmu pyrolyzed semi-char (SC), i.e., residuals of the coal pyrolysis chemical processing, and Shenhua bituminous coal (SB) were investigated in a 0.35 MW pilot-scale pulverized coal-fired furnace. The gas temperature and concentrations of gaseous species (O2, CO, CO_(2), NO_(x) and HCN) were measured in the primary combustion zone at different blend ratios. It is found that the standoff distance of ignition changes monotonically from 132 to 384 mm with the increase in pyrolyzed semi-char blend ratio. The effects on the combustion characteristics may be neglected when the blend ratio is less than 30%. Above the 30% blend ratio, the increase in blend ratio postpones ignition in the primary stage and lowers the burnout rate. With the blend ratio increasing, NO_(x) emission at the furnace exit is smallest for the 30% blend ratio and highest for the 100% SC. The NO_(x) concentration was 425 mg/m^(3) at 6% O_(2) and char burnout was 76.23% for the 45% blend ratio. The above results indicate that the change of standoff distance and NO_(x) emission were not obvious when the blend ratio of semi-char is less than 45%, and carbon burnout changed a little at all blend ratios. The goal of this study is to achieve blending combustion with a large proportion of semi-char without great changes in combustion characteristics. So, an SC blend ratio of no more than 45% can be suitable for the burning of semi-char.

Optimization of substrate ratio for beer production from finger millet and barley

Seventeen designed experiments were conducted in three steps(malting,brewing and fermentation)to produce beer from barley,finger millet and the combination of both.Effects of independent variables with three levels for each i.e.blend ratios of grains(100:0,50:50,0:100),kilning temperature(50℃,70℃,90℃)and malted grain to water ratios(1:3,1:5,1:7)were investigated on product quality.The results of the study indicated that all the independent parameters i.e.blend ratio,kilning temperature and slurry ratio affected the responses(pH,colour,bitterness and alcohol content)significantly.Optimum values of parameters,from the simultaneous optimization done using Design Expert 8.0.6.1 software,for beer production,were found to be 68:32 blend ratio,50℃ kilning temperature and 1:7 slurry ratio.The model F-value was found to be highly significant at 1% level of significance for all the responses.All the responses could be predicted by fitting the second order mathematical model and adequacy checked by R^(2).

Experimental Investigation for Co-Combustion Characteristics of Semi-Coke and Bituminous Coal in a 3 MWth Tangential Combustion Facility

An experimental investigation was conducted in a 3 MW pilot-scale tangential combustion facility to explore the co-combustion characteristics of bituminous coal mixed with semi-coke.The thermal gravimetric analyzer(TGA)was used to obtained fuel thermal analysis.The results presented effects of semi-coke blending ratio(BR)on average furnace temperature,ignition temperature,NO emission and combustion efficiency.The excess air coefficient in main combustion sections and outlet were fixed at 0.85 and 1.2 while BR increased from 0%to 50 wt.%.The temperature profiles of combustion decreases along the height of furnace while average furnace temperature fluctuates slightly with an increasing BR.The concentration of NO has an increasing tendency with the increasing of BR.The ignition temperature obtained from TGA measurement agreed well with experiment result.In addition,combustion efficiency was not sensitive to BR and decreased slightly with the increasing BR.

Mathematical models for some problems in textile engineering and its corresponding discussions

Textile industry is very important to the development of Chinese industry and econ-omy.Image processing techniques are beneficial to improve the quality of cotton goods.Suitable blending ratio of yarn is good for it.It is significant to measure the blending ratio of yarn in the practice of textile engineering.Combined with results done by other scholars,this paper uses the concepts of acreage index,abnormity index and fluctuation index.Based on these morphologic indices,it is convenient to construct corresponding eigenvector and to discuss useful mathematical method for the cluster analysis during the measurement of the blending ratio.This paper also sets up some kinds of nonlin-ear optimization model for the problem.Using classical integer programming algorithm,support vector machine algorithm and genetic algorithm to the problem,we get fine results for cluster analysis.Finally,we give out another problem of image processing and have some discussions about it.