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"worksheets": [
{
"cells": [
{
"cell_type": "code",
"collapsed": false,
"input": [
"Chapter 12 : Pneumatic Conveying\n"
],
"language": "python",
"metadata": {},
"outputs": []
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"example 12.1 page no : 240"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"\n",
"import math \n",
"from numpy import *\n",
"\n",
"# Initialization of Variable\n",
"rho = 1.22\n",
"pi = 3.1428\n",
"rhos = 518.\n",
"rhoav = 321.\n",
"mu = 1.73/10**5\n",
"g = 9.81\n",
"d = 0.65/1000\n",
"d2 = 25.5/100 #dia of duct\n",
"ms = 22.7/60 #mass flow rate\n",
"\n",
"#calculation\n",
"e = (rhos-rhoav)/(rhos-rho)\n",
"#coeff of quadratic eqn in U\n",
"#a*x**2+b*x+c = 0\n",
"c = -(1-e)*(rhos-rho)*g\n",
"b = 150.*(1-e)**2*mu/d**2/e**3\n",
"a = 1.75*(1.-e)*rho/d/e**3\n",
"y = poly1d([a,b,c],False)\n",
"U = roots(y)\n",
"Us = ms*4/pi/d2**2/rhos #superficial speed\n",
"Ua = e/e*(U[1]/e+Us/(1-e))\n",
"print \"the actual linear flow rate through duct in (m/s): %.4f\"%Ua\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"the actual linear flow rate through duct in (m/s): 0.2059\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"example 12.2 page no : 243"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"\n",
"import math \n",
"\n",
"# Initialization of Variable\n",
"rho = 1.22 #density of air\n",
"pi = 3.1428\n",
"rhos = 910. #density of polyethene\n",
"d = 3.4/1000. #dia of particles\n",
"mu = 1.73/10**5.\n",
"g = 9.81\n",
"dt = 3.54/100. #dia of duct\n",
"\n",
"#calculation\n",
"a = 2.*d**3*rho*g*(rhos-rho)/3/mu**2\n",
"print \"R/rho/U**2*(Re**2) = %.4f\"%a\n",
"\n",
"#using Chart\n",
"Re = 2.*10**3\n",
"U = mu*Re/d/rho\n",
"b = U/(g*dt)**.5\n",
"if b>0.35:\n",
" print \"choking can occur of this pipe system\"\n",
"else:\n",
" print \"choking can not occur of this pipe system\"\n",
"\n",
"#part 2\n",
"Uc = 15. #actual gas velocity\n",
"e = ((Uc-U)**2/2./g/dt/100.+1)**(1./-4.7)\n",
"Usc = (Uc-U)*(1-e) #superficial speed of solid\n",
"Cmax = Usc*rhos*pi*dt**2./4\n",
"print \"the maximum carrying capacity of polythene particles in (kg/s) %.4f\"%Cmax\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"R/rho/U**2*(Re**2) = 952227.8618\n",
"choking can occur of this pipe system\n",
"the maximum carrying capacity of polythene particles in (kg/s) 0.5949\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"example 12.3 page no : 245"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"import math \n",
"\n",
"# Initialization of Variable\n",
"rho = 1.22 #density of air\n",
"pi = 3.1428\n",
"rhos = 1400. #density of coal\n",
"mu = 1.73/10**5.\n",
"g = 9.81\n",
"U = 25.\n",
"Ut = 2.80\n",
"l = 50.\n",
"ms = 1.2 #mass flow rate\n",
"mg = ms/10. #mass flow of gas\n",
"\n",
"#calculation\n",
"Qs = ms/rhos #flow of solid\n",
"Qg = mg/rho #flow of gas\n",
"us = U-Ut #actual linear velocity\n",
"A = Qg/U\n",
"Us = Qs/A #solid velocity\n",
"e = (us-Us)/us\n",
"d = math.sqrt(4*A/pi)\n",
"def fround(x,n):\n",
" # fround(x,n)\n",
" # Round the floating point numbers x to n decimal places\n",
" # x may be a vector or matrix# n is the integer number of places to round to\n",
" y = round(x*10**n)/10.**n\n",
" return y\n",
"\n",
"d = fround(d,4)\n",
"Re = d*rho*U/mu\n",
"\n",
"#using moody's chart\n",
"phi = 2.1/1000 #friction factor\n",
"P1 = 2*phi*U**2*l*rho/d*2\n",
"f = 0.05/us\n",
"P2 = 2*l*f*(0.0098)*rhos*us**2/d\n",
"P2 = fround(P2/1000,1)*1000\n",
"delP = rho*e*U**2+rhos*(0.0098)*us**2+P1+P2\n",
"#print (delP,\"the pressure difference in kN/m**2 \")\n",
"print 'The Pressure value in kN/m**2 is %.1f'%(delP/1000)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The Pressure value in kN/m**2 is 33.5\n"
]
}
],
"prompt_number": 4
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"example 12.4 page no : 250"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"\n",
"import math \n",
"\n",
"# Initialization of Variable\n",
"rho = 1.22 #density of air\n",
"pi = 3.1428\n",
"rhos = 1090. #density of steel\n",
"mu = 1.73/10.**5\n",
"g = 9.81\n",
"d = 14.5/100.\n",
"Qg = 0.4\n",
"Qs = 5000./3600./1090.\n",
"Ut = 6.5\n",
"ar = 0.046/1000 #absolute roughness\n",
"l = 18.5 #length\n",
"\n",
"#calculation\n",
"def fround(x,n):\n",
" # fround(x,n)\n",
" # Round the floating point numbers x to n decimal places\n",
" # x may be a vector or matrix# n is the integer number of places to round to\n",
" y = round(x*10**n)/10**n\n",
" return y\n",
"\n",
"Us = Qs/pi/d**2*4 #solid velocity\n",
"U = Qg/pi/d**2*4\n",
"us = U-Ut #actual linear velocity\n",
"e = 1-Us/us\n",
"e = fround(e,4)\n",
"Re = rho*U*d/mu\n",
"rr = ar/d #relative roughness\n",
"\n",
"#using moody's diagram\n",
"phi = 2.08/1000\n",
"P1 = 2*phi*U**2*l*rho/d*2\n",
"f = 0.05/us\n",
"P2 = 2*l*f*(1-e)*rhos*us**2/d\n",
"P2 = fround(P2/1000,2)*1000\n",
"delP = rhos*(1-e)*us**2+rhos*(1-e)*g*l+P1+P2\n",
"#print (delP,\"the pressure difference in kN/m**2 \")\n",
"print 'The Pressure value in kN/m**2 is %.2f'%(delP/1000)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The Pressure value in kN/m**2 is 4.21\n"
]
}
],
"prompt_number": 6
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"example 12.5 pageno :254"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"\n",
"import math \n",
"\n",
"# Initialization of Variable\n",
"l = 25.\n",
"pi = 3.1428\n",
"rhos = 2690. #density of ore\n",
"emin = 0.6\n",
"emax = 0.8\n",
"g = 9.81\n",
"\n",
"#calculation\n",
"Pmax = rhos*(1-emin)*g*l\n",
"print \"The maximum pressure drop in (N/m**2):\",Pmax\n",
"Pmin = rhos*(1-emax)*g*l\n",
"print \"The minimum pressure drop in (N/m**2):\",Pmin\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The maximum pressure drop in (N/m**2): 263889.0\n",
"The minimum pressure drop in (N/m**2): 131944.5\n"
]
}
],
"prompt_number": 7
},
{
"cell_type": "code",
"collapsed": false,
"input": [],
"language": "python",
"metadata": {},
"outputs": []
}
],
"metadata": {}
}
]
}