This approach is sometimes called the Ponchon-Savarit Method. Working on the Hx diagram is more general than a McCabe-Thiele construction, because it. Ponchon – Savarit Method Presentation by. Prof. K. V. Rao Programme Director Department of Petroleum Engineering & Petrochemical Engineering. Lever Arm. Modified versions of the Ponchon-Savarit and McCabe-Thiele methods are presented which incorporate a correct analysis of the feed region in the case of partly.
|Country:||Sao Tome and Principe|
|Published (Last):||27 December 2007|
|PDF File Size:||3.17 Mb|
|ePub File Size:||15.25 Mb|
|Price:||Free* [*Free Regsitration Required]|
This line represents the system enthalpy balance, and so is called the overall enthalpy line. Distillation calculations can be performed graphically on an enthalpy-concentration Hx diagram. The reflux is a saturated liquid and feed enters the column at the optimum stage.
Ponchon Savarit Method
For an adiabatic process, the feed and products mrthod be colinear on an Hx diagram. On an Hx diagram, there isn’t an equilibrium curve — it has expanded to a region, and merhod point from the xy equilibrium curve is represented by a tie line. Apr 21, 5. One of the tools of graphical solution is the notion of colinearity. The bold black dots show the location of the feed and the stripping and rectifying difference points.
This has been used before if you have used lever arm principles. Plot the feed and product points. This will run a special program that should cause them to be formatted for viewing by your browser.
I see where the problem is coming from. The tie lines are shown in purple. Yes, my password is: My understanding is that the McCabe Thiele method assumes that the liquid and savariy molar flow rates are constant in each section of the column.
Eitherway you could actually compute for the number of stages using M-T while incorporating the enthalpy balances I think you know that as wellbut personally I find P-S ;onchon faster than M-T incorporating such balances because at least with P-S you just have to continually draw straight lines without having to worry about recomputing the operating and stripping lines every single time, lol.
Join Physics Forums Today! Equilibrium data is collected.
Ponchon-Savarit Graphical Equilibrium Stage Method – Wolfram Demonstrations Project
Log in or Sign up. The Ponchon Savarit method does not make this simplifying assumption, so it is more accurate. You can set values for the feed quality and feed, distillate, and bottom compositions to obtain the corresponding Ponchon—Savarit graphical construction and the number of column stages. The operating lines are developed methpd enthalpy balances on the rectifying and stripping sections just as in the McCabe-Thiele approach operating equations were developed from the equivalent component balances.
The column is to operate at 1 atm.
savarig The operating lines will connect the point representing the liquid on a stage with coordinates x nh n to the point representing the adjusted enthalpy at the appropriate end of the column. If the saturation curves show significant changes in curvature or separation, it suggests that to assume equimolar overflow will introduce error.
Do you already have an account?
Apr 19, 3. MaylisApr 19, Your first stage is drawn correctly. While doing constructions on methid yx diagram, a “pinch” was pinchon as the intersection point between the equilibrium curve and the operating curve. You may want to compare it with a traditional McCabe graph. Apr 21, 6. Its intersection with the saturated vapor curve will be the point V 2. A feed containing 40 mole percent n- hexane and 60 percent n- octane is fed to a distillation column. The overall enthalpy line is then drawn from D’, through F.
Wavarit intersection is the point L 1 liquid on tray 1. Then the overall enthalpy line is drawn from h Dp through the feed point, and the intersection with x B gives h Bp.
Rearranging the enthalpy balance gives: This graphical method uses both material and energy balances to determine the number of theoretical stages required to achieve a specific separation.
Ponchon-Savarit Graphical Equilibrium Stage Method
Thus, it is useful to poonchon our distillation system to be adiabatic, by bringing the condenser and reboiler inside the system boundary. The operating lines for the stripping and rectifying sections are shown in cyan and green, respectively. MaylisApr 21, The “pinch point” also expands, resulting in a single line where the operating and tie lines overlap. Assume that a total condenser is used.
The drawing itself is incorrect Your name or email address: Follow the tie line that passes through the V 1 point back poncohn the saturated liquid curve.
I was unaware that it was supposed to be from the vapor curve that I do the next line. This approach is sometimes called the Ponchon-Savarit Method.
If the dew point and bubble point lines are more or less straight and roughly parallel, it indicates that the latent heat of vaporization is basically constant with respect to composition.