1 | #*------------------------------------------------------------------- |
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2 | * EMSO Model Library (EML) Copyright (C) 2004 - 2007 ALSOC. |
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3 | * |
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4 | * This LIBRARY is free software; you can distribute it and/or modify |
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5 | * it under the therms of the ALSOC FREE LICENSE as available at |
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6 | * http://www.enq.ufrgs.br/alsoc. |
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7 | * |
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8 | * EMSO Copyright (C) 2004 - 2007 ALSOC, original code |
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9 | * from http://www.rps.eng.br Copyright (C) 2002-2004. |
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10 | * All rights reserved. |
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11 | * |
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12 | * EMSO is distributed under the therms of the ALSOC LICENSE as |
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13 | * available at http://www.enq.ufrgs.br/alsoc. |
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14 | * |
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15 | *--------------------------------------------------------------------- |
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16 | * Series of CSTR and PFR |
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17 | *---------------------------------------------------------------------- |
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18 | * Solved problem from Fogler (1999) |
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19 | * Problem number: 2-2 at 2-7 |
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20 | * Page: 38-49 (Brazilian edition, 2002) |
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21 | *---------------------------------------------------------------------- |
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22 | * |
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23 | * Description: |
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24 | * Sample to comparative between volumes to specific outlet molar |
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25 | * conversion of CSTR and PFR by means of several different |
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26 | * configurations |
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27 | * |
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28 | * Assumptions: |
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29 | * * steady-state |
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30 | * * isotermic and isobaric system |
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31 | * * gaseous phase |
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32 | * |
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33 | * Specify: |
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34 | * * the inlet stream (F,X) |
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35 | * * the expression of rate of reaction |
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36 | * * the initial volume |
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37 | * * the outlet conversion |
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38 | * |
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39 | * Configurations: |
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40 | * * only one CSTR |
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41 | * * only one PFR |
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42 | * * 2 CSTRs in series |
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43 | * * 2 PFRs in series |
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44 | * * one PFR followed for one CSTR |
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45 | * * one CSTR followed for one PFR |
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46 | * |
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47 | *---------------------------------------------------------------------- |
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48 | * Author: Rodolfo Rodrigues and Argimiro R. Secchi |
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49 | * $Id: series_reactors.mso 82 2006-12-08 20:11:44Z paula $ |
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50 | *--------------------------------------------------------------------*# |
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51 | |
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52 | using "types"; |
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53 | |
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54 | |
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55 | #*--------------------------------------------------------------------- |
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56 | * Model of a stream |
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57 | *--------------------------------------------------------------------*# |
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58 | |
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59 | Model stream |
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60 | PARAMETERS |
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61 | NComp as Integer (Brief="Number of components", Default=1); |
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62 | VARIABLES |
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63 | F(NComp)as flow_mol (Brief="Molar flow", Unit="mol/s"); |
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64 | X(NComp)as fraction (Brief="Molar conversion"); |
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65 | end |
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66 | |
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67 | |
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68 | #*--------------------------------------------------------------------- |
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69 | * Model of a steady-state, isotermic, and isobaric CSTR |
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70 | *--------------------------------------------------------------------*# |
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71 | |
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72 | Model cstr |
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73 | VARIABLES |
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74 | in Inlet as stream; # Inlet stream |
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75 | out Outlet as stream; # Outlet stream |
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76 | r as reaction_mol(Brief="Rate of reaction", Unit="mol/l/s"); |
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77 | V as volume (Brief="Volume", Unit="l", Upper=2e3); |
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78 | |
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79 | EQUATIONS |
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80 | "Component molar balance" |
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81 | Inlet.F - Outlet.F = (-r)*V; |
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82 | |
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83 | "Outlet molar flow" |
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84 | Outlet.F = Inlet.F*(1 - Outlet.X); |
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85 | end |
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86 | |
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87 | |
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88 | #*--------------------------------------------------------------------- |
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89 | * Model of a steady-state, isotermic, and isobaric PFR |
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90 | *--------------------------------------------------------------------*# |
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91 | |
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92 | Model pfr |
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93 | VARIABLES |
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94 | in Inlet as stream; # Inlet stream |
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95 | out Outlet as stream; # Outlet stream |
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96 | V as volume (Brief="Volume", Unit="l", Upper=2e3); |
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97 | r as reaction_mol(Brief="Rate of reaction", Unit="mol/l/s"); |
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98 | |
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99 | EQUATIONS |
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100 | "Molar balance" |
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101 | diff(V) = Inlet.F/(-r)*"1/s"; |
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102 | |
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103 | "Change time in X" |
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104 | Outlet.X = time*"1/s"; |
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105 | |
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106 | "Molar flow" |
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107 | Outlet.F = Inlet.F*(1 - Outlet.X); |
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108 | end |
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109 | |
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110 | |
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111 | #*--------------------------------------------------------------------- |
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112 | * Model of a discreted steady-state, isotermic, and isobaric PFR |
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113 | *--------------------------------------------------------------------*# |
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114 | |
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115 | Model pfr_d |
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116 | PARAMETERS |
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117 | N as Integer (Brief="Number of discrete points", Default=200); |
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118 | |
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119 | VARIABLES |
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120 | in Inlet as stream; # Inlet stream |
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121 | out Outlet as stream; # Outlet stream |
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122 | V(N) as volume (Brief="Volume", Unit="l", Upper=2e3); |
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123 | X(N) as fraction (Brief="Molar conversion"); |
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124 | dx as fraction (Brief="Conversion increment"); |
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125 | r(N) as reaction_mol (Brief="Rate of reaction", Unit="mol/l/s"); |
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126 | F(N) as flow_mol (Brief="Molar flow", Unit="mol/s"); |
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127 | |
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128 | EQUATIONS |
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129 | "Discrete interval" |
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130 | dx = X(N)/N; |
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131 | |
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132 | for i in [2:N] |
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133 | "Molar balance" |
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134 | V(i) - V(i-1) = Inlet.F*dx/(-r(i)); |
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135 | "Discrete molar conversion" |
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136 | X(i-1) = X(i) - dx; |
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137 | end |
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138 | |
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139 | "Molar flow" |
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140 | F = Inlet.F*(1 - X); |
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141 | |
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142 | "Outlet molar flow" |
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143 | Outlet.F = F(N); |
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144 | |
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145 | "Outlet molar conversion" |
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146 | Outlet.X = X(N); |
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147 | end |
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148 | |
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149 | |
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150 | #*--------------------------------------------------------------------- |
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151 | * Example 2-2: Scale-up an isotermic CSTR in gaseous phase |
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152 | *--------------------------------------------------------------------*# |
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153 | |
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154 | FlowSheet cstr_sample |
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155 | PARAMETERS |
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156 | R as Real (Brief="Universal gas constant", Unit="atm*l/mol/K", Default=0.082); |
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157 | T as temperature (Brief="Temperatura in the reactor", Unit="K"); |
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158 | P as pressure (Brief="Pressure in the reactor", Unit="atm"); |
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159 | zin as fraction (Brief="Inlet molar fraction"); |
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160 | v0 as flow_vol (Brief="Volumetric flow"); |
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161 | |
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162 | VARIABLES |
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163 | Vt as volume (Brief="Total reactor volume", Unit="l"); |
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164 | |
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165 | DEVICES |
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166 | Inlet as stream; # Inlet stream |
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167 | R1 as cstr; |
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168 | |
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169 | CONNECTIONS |
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170 | Inlet to R1.Inlet; |
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171 | |
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172 | EQUATIONS |
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173 | "Inlet molar flow" |
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174 | Inlet.F = (zin*P/(R*T))*v0; |
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175 | |
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176 | "Rate of reaction" |
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177 | (-R1.r) = (0.0092*R1.Outlet.X^3 - 0.0153*R1.Outlet.X^2 + 0.0013*R1.Outlet.X + 0.0053)*"mol/l/s"; |
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178 | |
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179 | "Total reactor volume" |
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180 | Vt = R1.V; |
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181 | |
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182 | SPECIFY |
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183 | "Inlet conversion" |
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184 | Inlet.X = 0.0; |
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185 | "Required conversion" |
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186 | R1.Outlet.X = 0.8; |
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187 | |
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188 | SET |
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189 | v0 = 6.0*"l/s"; |
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190 | T = 422.2*"K"; |
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191 | P = 10*"atm"; |
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192 | zin = 0.5; |
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193 | |
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194 | OPTIONS |
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195 | mode = "steady"; |
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196 | end |
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197 | |
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198 | |
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199 | #*--------------------------------------------------------------------- |
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200 | * Example 2-3: Scale-up an isotermic PFR in gaseous phase |
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201 | *--------------------------------------------------------------------*# |
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202 | |
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203 | FlowSheet pfr_sample |
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204 | DEVICES |
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205 | Inlet as stream; # Inlet stream |
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206 | R1 as pfr; |
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207 | |
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208 | CONNECTIONS |
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209 | Inlet to R1.Inlet; |
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210 | |
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211 | EQUATIONS |
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212 | "Rate of reaction" |
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213 | (-R1.r) = (0.0092*R1.Outlet.X^3 - 0.0153*R1.Outlet.X^2 + 0.0013*R1.Outlet.X + 0.0053)*"mol/l/s"; |
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214 | |
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215 | SPECIFY |
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216 | "Inlet molar flow" |
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217 | Inlet.F = 0.866541*"mol/s"; |
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218 | "Inlet conversion" |
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219 | Inlet.X = 0.0; |
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220 | |
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221 | INITIAL |
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222 | "Reactor volume" |
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223 | R1.V = 0.0*"l"; |
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224 | |
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225 | OPTIONS |
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226 | time = [0:0.004:0.8]; |
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227 | end |
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228 | |
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229 | |
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230 | #*--------------------------------------------------------------------- |
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231 | * Example 2-3: (discreted) |
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232 | *--------------------------------------------------------------------*# |
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233 | |
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234 | FlowSheet pfr_d_sample |
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235 | VARIABLES |
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236 | Vt as volume (Brief="Total reactor volume", Unit="l"); |
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237 | |
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238 | DEVICES |
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239 | Inlet as stream; # Inlet stream |
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240 | R1 as pfr_d; |
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241 | |
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242 | CONNECTIONS |
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243 | Inlet to R1.Inlet; |
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244 | |
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245 | EQUATIONS |
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246 | "Rate of reaction" |
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247 | (-R1.r) = (0.0092*R1.X^3 - 0.0153*R1.X^2 + 0.0013*R1.X + 0.0053)*"mol/l/s"; |
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248 | |
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249 | "Total reactor volume" |
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250 | Vt = R1.V(R1.N); |
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251 | |
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252 | # SET |
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253 | # R1.N = 100; |
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254 | |
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255 | SPECIFY |
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256 | "Inlet molar flow" |
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257 | Inlet.F = 0.866541*"mol/s"; |
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258 | "Inlet conversion" |
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259 | Inlet.X = 0.0; |
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260 | |
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261 | "Required conversion" |
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262 | R1.Outlet.X = 0.8; |
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263 | "Initial volume" |
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264 | R1.V(1) = 0.0*"l"; |
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265 | |
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266 | OPTIONS |
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267 | mode = "steady"; |
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268 | end |
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269 | |
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270 | |
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271 | #*--------------------------------------------------------------------- |
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272 | * Example 2-4: Comparing volumes between one CSTR and one PFR |
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273 | *--------------------------------------------------------------------*# |
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274 | |
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275 | FlowSheet comparative |
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276 | VARIABLES |
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277 | V_cstr as volume (Brief="CSTR volume", Unit="l"); |
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278 | V_pfr as volume (Brief="PFR volume", Unit="l"); |
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279 | |
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280 | DEVICES |
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281 | Inlet as stream; # Inlet stream |
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282 | CSTR as cstr; |
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283 | PFR as pfr_d; |
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284 | |
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285 | CONNECTIONS |
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286 | Inlet to CSTR.Inlet; |
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287 | Inlet to PFR.Inlet; |
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288 | |
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289 | EQUATIONS |
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290 | "Rate of reaction in CSTR" |
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291 | (-CSTR.r) = (0.0092*CSTR.Outlet.X^3 - 0.0153*CSTR.Outlet.X^2 + 0.0013*CSTR.Outlet.X + 0.0053)*"mol/l/s"; |
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292 | "Rate of reaction in PFR" |
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293 | (-PFR.r) = (0.0092*PFR.X^3 - 0.0153*PFR.X^2 + 0.0013*PFR.X + 0.0053)*"mol/l/s"; |
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294 | |
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295 | "CSTR volume" |
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296 | V_cstr = CSTR.V; |
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297 | "PFR volume" |
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298 | V_pfr = PFR.V(PFR.N); |
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299 | |
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300 | # SET |
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301 | # PFR.N = 100; |
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302 | |
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303 | SPECIFY |
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304 | "Inlet molar flow" |
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305 | Inlet.F = 5.0*"mol/s"; |
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306 | "Inlet conversion" |
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307 | Inlet.X = 0.0; |
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308 | |
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309 | "Required CSTR conversion" |
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310 | CSTR.Outlet.X = 0.6; |
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311 | "Required PFR conversion" |
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312 | PFR.Outlet.X = 0.6; |
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313 | |
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314 | "Initial volume in PFR" |
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315 | PFR.V(1) = 0.0*"l"; |
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316 | |
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317 | OPTIONS |
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318 | mode = "steady"; |
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319 | end |
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320 | |
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321 | |
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322 | #*--------------------------------------------------------------------- |
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323 | * Example 2-5: two CSTRs in serie |
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324 | *--------------------------------------------------------------------*# |
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325 | |
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326 | FlowSheet cstr_cstr |
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327 | VARIABLES |
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328 | V1 as volume (Brief="1st reactor volume", Unit="l"); |
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329 | V2 as volume (Brief="2nd reactor volume", Unit="l"); |
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330 | Vt as volume (Brief="Total reactor volumes", Unit="l"); |
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331 | |
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332 | DEVICES |
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333 | Inlet as stream; # Inlet stream |
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334 | R1 as cstr; |
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335 | R2 as cstr; |
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336 | |
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337 | CONNECTIONS |
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338 | Inlet to R1.Inlet; |
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339 | R1.Outlet to R2.Inlet; |
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340 | |
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341 | EQUATIONS |
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342 | "Rate of reaction in 1st reactor" |
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343 | (-R1.r) = (0.0092*R1.Outlet.X^3 - 0.0153*R1.Outlet.X^2 + 0.0013*R1.Outlet.X + 0.0053)*"mol/l/s"; |
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344 | "Rate of reaction in 2nd reactor" |
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345 | (-R2.r) = (0.0092*R2.Outlet.X^3 - 0.0153*R2.Outlet.X^2 + 0.0013*R2.Outlet.X + 0.0053)*"mol/l/s"; |
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346 | |
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347 | "1st volume reactor" |
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348 | V1 = R1.V; |
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349 | "1st volume reactor" |
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350 | V2 = R2.V; |
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351 | "Total volume of reactors" |
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352 | Vt = V1 + V2; |
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353 | |
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354 | SPECIFY |
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355 | "Inlet molar flow" |
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356 | Inlet.F = 0.866541*"mol/s"; |
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357 | "Inlet conversion" |
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358 | Inlet.X = 0.0; |
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359 | |
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360 | "Required 1st reactor conversion" |
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361 | R1.Outlet.X = 0.4; |
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362 | "Required 2nd reactor conversion" |
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363 | R2.Outlet.X = 0.8; |
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364 | |
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365 | OPTIONS |
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366 | mode = "steady"; |
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367 | end |
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368 | |
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369 | |
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370 | #*--------------------------------------------------------------------- |
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371 | * Example 2-6: two PFRs in series (discreted) |
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372 | *--------------------------------------------------------------------*# |
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373 | |
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374 | FlowSheet pfr_pfr |
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375 | VARIABLES |
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376 | V1 as volume (Brief="1st reactor volume", Unit="l"); |
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377 | V2 as volume (Brief="2nd reactor volume", Unit="l"); |
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378 | Vt as volume (Brief="Total reactor volumes", Unit="l"); |
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379 | |
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380 | DEVICES |
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381 | Inlet as stream; # Inlet stream |
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382 | R1 as pfr_d; |
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383 | R2 as pfr_d; |
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384 | |
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385 | CONNECTIONS |
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386 | Inlet to R1.Inlet; |
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387 | R1.Outlet to R2.Inlet; |
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388 | |
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389 | EQUATIONS |
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390 | "Rate of reaction in 1st reactor" |
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391 | (-R1.r) = (0.0092*R1.X^3 - 0.0153*R1.X^2 + 0.0013*R1.X + 0.0053)*"mol/l/s"; |
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392 | "Rate of reaction in 2nd reactor" |
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393 | (-R2.r) = (0.0092*R2.X^3 - 0.0153*R2.X^2 + 0.0013*R2.X + 0.0053)*"mol/l/s"; |
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394 | |
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395 | "1st reactor volume" |
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396 | V1 = R1.V(R1.N); |
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397 | "1st reactor volume" |
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398 | V2 = R2.V(R2.N); |
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399 | "Total reactor volumes" |
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400 | Vt = V1 + V2; |
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401 | |
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402 | SPECIFY |
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403 | "Inlet molar flow" |
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404 | Inlet.F = 0.866541*"mol/s"; |
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405 | "Inlet conversion" |
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406 | Inlet.X = 0.0; |
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407 | |
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408 | "Required 1st reactor conversion" |
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409 | R1.Outlet.X = 0.4; |
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410 | "Required 2nd reactor conversion" |
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411 | R2.Outlet.X = 0.8; |
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412 | |
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413 | "Initial 1st reactor volume" |
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414 | R1.V(1) = 0.0*"l"; |
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415 | "Initial 2nd reactor volume" |
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416 | R2.V(1) = 0.0*"l"; |
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417 | |
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418 | OPTIONS |
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419 | mode = "steady"; |
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420 | end |
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421 | |
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422 | |
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423 | #*--------------------------------------------------------------------- |
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424 | * Example 2-7a: one PFR and one CSTR in series |
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425 | *--------------------------------------------------------------------*# |
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426 | |
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427 | FlowSheet pfr_cstr |
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428 | VARIABLES |
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429 | V1 as volume (Brief="1st reactor volume", Unit="l"); |
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430 | V2 as volume (Brief="2nd reactor volume", Unit="l"); |
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431 | Vt as volume (Brief="Total reactor volumes", Unit="l"); |
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432 | |
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433 | DEVICES |
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434 | Inlet as stream; # Inlet stream |
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435 | R1 as pfr_d; |
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436 | R2 as cstr; |
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437 | |
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438 | CONNECTIONS |
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439 | Inlet to R1.Inlet; |
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440 | R1.Outlet to R2.Inlet; |
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441 | |
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442 | EQUATIONS |
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443 | "Rate of reaction in 1st reactor" |
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444 | (-R1.r) = (0.0092*R1.X^3 - 0.0153*R1.X^2 + 0.0013*R1.X + 0.0053)*"mol/l/s"; |
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445 | "Rate of reaction in 2nd reactor" |
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446 | (-R2.r) = (0.0092*R2.Outlet.X^3 - 0.0153*R2.Outlet.X^2 + 0.0013*R2.Outlet.X + 0.0053)*"mol/l/s"; |
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447 | |
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448 | "1st reactor volume" |
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449 | V1 = R1.V(R1.N); |
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450 | "1st reactor volume" |
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451 | V2 = R2.V; |
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452 | "Total reactor volumes" |
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453 | Vt = V1 + V2; |
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454 | |
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455 | # SET |
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456 | # R1.N = 100; |
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457 | |
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458 | SPECIFY |
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459 | "Inlet molar flow" |
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460 | Inlet.F = 0.866541*"mol/s"; |
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461 | "Inlet conversion" |
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462 | Inlet.X = 0.0; |
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463 | |
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464 | "Required 1st reactor conversion" |
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465 | R1.Outlet.X = 0.5; |
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466 | "Required 2nd reactor conversion" |
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467 | R2.Outlet.X = 0.8; |
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468 | |
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469 | "Initial 1st reactor volume" |
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470 | R1.V(1) = 0.0*"l"; |
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471 | |
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472 | OPTIONS |
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473 | mode = "steady"; |
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474 | end |
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475 | |
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476 | |
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477 | #*--------------------------------------------------------------------- |
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478 | * Example 2-7b: one CSTR and one PFR in series |
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479 | *--------------------------------------------------------------------*# |
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480 | |
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481 | FlowSheet cstr_pfr |
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482 | VARIABLES |
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483 | V1 as volume (Brief="1st reactor volume", Unit="l"); |
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484 | V2 as volume (Brief="2nd reactor volume", Unit="l"); |
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485 | Vt as volume (Brief="Total reactor volumes", Unit="l"); |
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486 | |
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487 | DEVICES |
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488 | Inlet as stream; # Inlet stream |
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489 | R1 as cstr; |
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490 | R2 as pfr_d; |
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491 | |
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492 | CONNECTIONS |
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493 | Inlet to R1.Inlet; |
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494 | R1.Outlet to R2.Inlet; |
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495 | |
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496 | EQUATIONS |
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497 | "Rate of reaction in 1st reactor" |
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498 | (-R1.r) = (9.2*R1.Outlet.X^3 - 15.3*R1.Outlet.X^2 + 1.3*R1.Outlet.X + 5.3)*1e-3*"mol/l/s"; |
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499 | "Rate of reaction in 2nd reactor" |
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500 | (-R2.r) = (9.2*R2.X^3 - 15.3*R2.X^2 + 1.3*R2.X + 5.3)*1e-3*"mol/l/s"; |
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501 | |
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502 | "1st reactor volume" |
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503 | V1 = R1.V; |
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504 | "1st reactor volume" |
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505 | V2 = R2.V(R2.N); |
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506 | "Total reactor volumes" |
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507 | Vt = V1 + V2; |
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508 | |
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509 | # SET |
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510 | # R2.N = 100; |
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511 | |
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512 | SPECIFY |
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513 | "Inlet molar flow" |
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514 | Inlet.F = 0.866541*"mol/s"; |
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515 | "Inlet conversion" |
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516 | Inlet.X = 0.0; |
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517 | |
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518 | "Required 1st reactor conversion" |
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519 | R1.Outlet.X = 0.5; |
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520 | "Required 2nd reactor conversion" |
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521 | R2.Outlet.X = 0.8; |
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522 | |
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523 | "Initial 2nd reactor volume" |
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524 | R2.V(1) = 0.0*"l"; |
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525 | |
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526 | OPTIONS |
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527 | mode = "steady"; |
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528 | end |
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