Reboilers sketches

Fig. 3. Rough layout sketch (/) the two fined heaters F-1 and F-2 are located together but are separated from the other equipment with a subpipeway connecting the process area to the heater area (2) the reboiler E-2 is located adjacent to its column, T-1. The preheat exchanger E-4 is located adjacent to tower T-3 (J) the elevated overhead condenser E-3 is located next to the overhead accumulator V-1. Also, the ain condenser EE-3 is located adjacent to its overhead accumulator V-2 (4) the rest of the ain coolers (EE-1—3, -5) are grouped together ia a common fan stmcture (5) all equipment and related piping is routed to and from the existing piperack saving the addition of a new piperack (6) all pumps (P-1—P-6) are located ia a row under the piperack, and each...

Prepare a chemical engineering design of the second distillation unit, i.e. for the separation of n- and isobutyraldehyde. Make dimensioned sketches of the column, the reboiler and the condenser. 

Flooded condensers and flooded reboilers are sometimes used on distillation columns. In the sketch below, a hquid level is held in the condenser, covering some of the tubes. Thus a variable amount of heat transfer area is available to condense the vapor. Column pressure can be controlled by changing the distillate (or reflux) drawoff rate. 

Develop a mathematical model for the three-column train of distillation columns sketched below. The feed to the first column is 400 kg mol/h and contains four components (1, 2, 3, and 4), each at 25 mol %. Most of the lightest component is removed in the distillate of the first column, most of the next lightest in the second column distillate and the final column separates the final two heavy components. Assume constant relative volatilities throughout the system ai, CI2, and a3. The condensers are total condensers and the reboilers are partial. Trays, column bases, and reflux drums are perfectly mixed. Distillate flow rates are set by reflux drum... 

Another example is sketched in Fig. 8.3i>. A hot oil stream is used to reboil a distillation column. Controlling the flow rate of the hot oil does not guarantee a fixed heat input because the inlet oil temperature can vary and the AT requirements in the reboiler can change. The heat input Q can be computed from the flow rate and the inlet and outlet temperatures, and this Q can then be controlled. 

Two distillation columns are heat-inicgraled as shown in the sketch below. The first column has an auxiliary condenser to take any excess vapor that the second column does not need. The second column has an auxiliary reboiler that provides additional heat if required. 

Initial Sketch. Figure 2 shows a process flow diagram for a petrochemical plant (1,2). This drawing shows the feed and products so the designer knows what to allow for these lines in the interunit pipeway routing. The process engineer has indicated with notes which pieces of equipment will be located in elevated structures, such as the overhead condensers, and has also shown which equipment should be located close by other equipment, such as the reboiler next to its column. Primary instrumentation is shown to indicate that room is required for instrument drops to these control valves. All this... 

Reactors, fementation, 654,659,660 Reboilers, 206-208 control, 47 design example, 209 guide to selection, 208 sketches, 175... 

The most widely used is ammonia absorption in water. A flow-sketch of the process is in Figure 8.27. Liquid ammonia at a high pressure is obtained overhead in a stripper, and then is expanded through a valve and becomes the low temperature vapor-liquid mixture that functions as the refrigerant. The low pressure vapor is absorbed in weak liquor from the bottom of the stripper. Energy input to the refrigeration system is primarily that of the steam to the stripper reboiler and a minor amount of power to the pump and the cooling water circulation. 

We start by sketching a simple two-product distillation column, as shown in Fig. 1. This column is the unit operation most likely to be considered as a building block for these problems. The two-product distillation column splits its feed into two essentially disjoint product sets. The distillate contains species A, B, and C (plus, of course, a small amount of D and generally only traces of the other species) while the bottom product contains predominantly D and E. Heat is injected at the bottom into the reboiler, the hottest point in the column, and removed from the condenser at the top, the coldest point in the column. Liquid flows downward against a flow of vapor upward, with the more volatile species enriching as one moves up the column. 

Absorber and strippers may be classified as complex columns because they possess two feeds and because they possess neither an overhead condenser nor a reboiler. The sketch of the absorber in Fig. 4-1 depicts an historic application of absorbers in the natural gas industry. From a light gas stream such as natural gas that contains primarily methane plus small quantities of, say, ethane through n-pentane, the desired quantities of the components heavier than methane may be removed by contacting the natural gas stream with a heavy oil stream (say n-octane or heavier) in a countercurrent, multiple-stage column such as the one shown in Fig. 4-1. Since absorption is a heat-liberating process, the lean oil is customarily introduced at a temperature below the average temperature at which the column is expected to operate. The flow rate of the lean oil is denoted by L0, and the lean oil enters at the top of the column as implied by Fig. 4-1. The rich gas (which is sometimes called the wet gas) enters at the bottom of the... 

The sketch for a typical reboiled absorber is shown in Fig. 4-2. To demonstrate the formulation of the 2N Newton-Raphson method for reboiled absorbers, two different sets of specifications are considered. 

As indicated in the sketch below, a mixture of propane and n-pentane is to be separated by distillation at lOOpsia. Two designs are to be made by the Ponchon-Savarit method. In the first design, a total overhead condenser and a partial bottoms reboiler are to be used with saturated reflux at a flow rate of twice the minimum value. In the second design, a total overhead condenser, an inter-... 

In the sketch below, 150kgmole/hr of a saturated liquid Li at 758 kPa of molar composition—propane 10%, n-butane 40%, and n-pentane 50%—enters the reboiler from stage 1. What are the composition and amounts of Vb and B What is Qr, the reboiler duty ... 

The distillation column sketched above has an intermediate reboiler and a vapor side-stream. Sketch a control concept diagram showing the following control objectives ... 

EXAMPLE 9.1. Consider the process with a series cascade control system sketched in Fig. 9.le. A typical example is a secondary loop in which the flow rate of condensate from a flooded reboiler is the manipulated variable M, the secondary variable is the flow rate of steam to the reboiler, and the primary variable is the temperature in a distillation column. We assume that the secondary controller Gci and the primary controller Gci are both proportional only. 

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