Particle TechnologyExp.1 Screen Analysis

Name: Kareem TarekI.D: 115780

Chemical- Year 3Supervised by:

Dr. Mamdouh Gadalla TA. Mai Hassan TA. Rana Adel

TABLE OF ContentsAbstract........................................................3Introduction..................................................3Experimental procedure...............................4

Problem Statement.…………………………………….5References....................................................7

AbstractScreening is a separation technique of solid particles based solely on size. The objective of this experiment is to determine the relative proportions of diverse grain sizes as they are dispersed among certain size assortments by means of Sieve analysis.

IntroductionThe grain size distribution is an illustration of the approximated distribution of dirt grain sizes for a soil. The sieve analysis, also known as screen, measures the dry mass of the material held on every single sieve in a stack of sieves, whereas the sieve opening sizes differ from the biggest to smallest going from the top to the bottom of the stack. All the particles held on a specific sieve will have an ‘intermediate size’ or ‘average diameter’ that is marginally smaller than the openings of the sieve above and bigger than all the sieves below. Therefore the individual particle sizes are not measured but the scope of sizes (i.e. tinier than the sieve above and larger than the sieve retaining the particle) is defined. The advantages of the sieve analysis include: effortless handling, minimal investment fee, precise and reproducible results in a relatively short period of time and the potential to distinct the particle size fractions.

Sieving MethodsVibratory Sieving The sample is propelled upwards by the vibrations of the sieve and then cascades down because of gravitation forces.

 Air Jet Sieving It is a sieving machine designed for single sieving, only one sieve is employed for each sieving process. The sieve itself does not move throughout the procedure.

Tap Sieving In a tap sieve shaker a horizontal, circular movement is overlaid by a vertical motion created by tapping pulsations.

Horizontal Sieving In Horizontal Sieving, the shaker the sieves move in horizontal circles in a plane. Horizontal sieve shakers are preferably used for flat, long or fibrous samples. Due to the horizontal sieving motion, the particles barely vary their bearings on the sieve

Wet Sieving Generally, sieve analysis is performed with dry materials. Nevertheless, there are numerous appliances in which wet sieving cannot be eluded, e.g. if the material to be tested is a very fine sample (< 45 µm) dry sieving would result in an obstruction of the sieve.

Sieve analysis limitations Dry sieving can be considerably less accurate when dealing alongside materials that are finer than 100 mesh. This is because the mechanical energy necessary to make particles bypass across an opening and the external attraction effects between the particles themselves and between particles and the screen increase as the particle size drops. Sieve analysis presumes that all particles will be round/spherical shaped or concerning so, the particles will make way across the square openings when the particle diameter is below the size of the square onset in the screen. Sieve analysis will not produce a reliable result for flat and spread particles

Experimental Procedure

1) Cautiously brush the sieves to guarantee that all loose material is eliminated. To avert any impairment to the sieves2) Acquire the oven dry mass of the sample. 3) Acquire the weight of the pan. 4) Rack the sieves in order into a stack with the pan on the bottom. 5) Empty the sample into the top sieve and place the lid on the top sieve. 6) Position the sieve on the mechanical shaker and run the shaker for 10 to 15 minutes. 7) Take out the sieves from the shaker and obtain the mass of soil

Problem statement It is vital from you to calculate the specific surface area per

unit volume and the mean volume surface diameter using cumulative and differential method. Comprehending that the shape factor is equal to 1.2 and the particle density of the sand is 2600 kg/m3. Disregard the mass of sand held on the upper screen and the pan for the total mass so as to have zero mass on both the upper screen and the pan.

Differential analysis method:

Sieve Diameter(mm)

Retained mass (g)

Fraction Mean diameter

Fraction/ mean

diameter

Sieve 1 4.75 15 0.0075 0 0

Sieve 2 2.36 185.5 0.092 3.555 0.0258

Sieve 3 1.25 171.5 0.085 1.805 0.0471

Sieve 4 0.6 372 0.186 0.925 0.2011

Sieve 5 0.3 1101.5 0.55 0.45 1.22

Sieve 6 0.15 114.5 0.057 0.225 0.253

Sieve 7 0.075 25.5 0.012 0.1125 0.106

Sieve 8 0 11.5 0.0057 0.0375 0.152

Total=1997

Total=1.853

Dvs=1/1.853=0.539mm

λ=1.2 ρ=2600 kg/m3

Aw=6 λ/ ρDvs=6*1.2*1.853*1000/2600=5.131 m2/kg

Cumulative analysis method:

Diameter(mm) Fraction Cumulative fraction фc

1//Dp(m-1)

4.75 0.0075 0.0075 210.526

2.36 0.092 0.0995 423.728

1.25 0.085 0.1895 800

0.6 0.186 0.3705 1666.66

0.3 0.55 0.9205 3333.33

0.15 0.057 0.9775 6666.66

0.075 0.012 0.9895 13333.33

0 0.0057 0.9952 0

Ʃ фc=3.547

1/DP- фc=A(m-1)

Aw=6 λA/ ρ

A=0.5912/2*(423.728+2(800+1666.66+3333.33)+6666.66)=5051.912 m-1

Aw=6*1.2*5051.912/2600=13.989 m2/kg

References http://www.mep.net.au/wpmep/wp-content/uploads/2013/07/

MEP_expert_guide_sieving_en.pdf https://www.scribd.com/doc/206350274/Sieve-Analysis