Batch Pan

Next to natural solar evaporation, the batch pan (Figure 1) is one of the oldest methods of concentration. It is somewhat outdated in today's technology, but is still used in a few limited applications, such as the concentration of jams and jellies where whole fruit is present and in processing some pharmaceutical products. Up until the early 1960's, batch pan also enjoyed wide use in the concentration of corn syrups. With a batch pan evaporator, product residence time normally is many hours. Therefore, it is essential to boil at low temperatures and high vacuum when a heat sensitive or thermodegradable product is involved. The batch pan is either jacketed or has internal coils or heaters. Heat transfer areas normally are quite small due to vessel shapes, and heat transfer coefficients (HTC’s) tend to be low under natural convection conditions. Low surface areas together with low HTC's generally limit the evaporation capacity of such a system. Heat transfer is improved by agitation within the vessel. In many cases, large temperature differences cannot be used for fear of rapid fouling of the heat transfer surface. Relatively low evaporation capacities, therefore, limit its use.

Titanium Dioxide

The production of titanium dioxide pigments involves reaction between sulfuric acid and the ore which contains iron, titanium sulfate and other compounds. After pretreatment, which includes the crystallization of iron as ferrous sulfate, the liquor is heated and hydrolyzed to precipitate Titanium dioxide. Prior to this operation, the concentration of liquor has to be adjusted by the evaporation of water. It is essential that this process takes place in an evaporator with short heat contact times in order to avoid the premature hydrolysis that occurs with prolonged heating, which subsequently causes fouling of the heat surface and blockage of the tubes. Although the liquor contains a high proportion of sulfuric acid, the presence of other ions in solution may inhibit corrosion, so that copper often can be used for heat transfer surfaces. Titanium is another material used for this application. Generally, single or multiple effect rising film evaporators are used for this duty, the number of effects being determined by throughput and by assessing the cost of operation against the increase in capital required for additional equipment. In some cases, it is economically attractive to operate the evaporator as a single effect unit at atmospheric pressure using the vapor given off for preheating. The liquor is discharged at a temperature in excess of 212°F (100°C), reducing the subsequent thermal load at the hydrolysis stage.

Acetaminophen

Acetaminophen, sold under the trade name Tylenol, is a widely used anal- gesic and antipyretic that is an over-the-counter drug. Combined with codeine it is one of the top five prescription drugs. Acetaminophen is pre- pared by treating p-aminophenol with a mixture of glacial acetic acid and acetic anhydride.

Chemical reaction engineering By Levenspiel O. (3ed., Wiley, 1998).pdf

Chemical Reaction Engineering Book Description

Publisher: John Wiley & Sons
Author: Octave Levenspiel, Cctave Levenspiel
Edition Number: 3
Language: English
ISBN:
047125424X
EAN:
9780471254249
No. of Pages: 688
Publish Date: 1998-08-31

Chemical Process and Design Handbook

Introduction to Chemical Reaction Engineering and Kinetics - RW Missen

Heat Transfer Handbook - Wiley Bejan 2003

Book: Heat Transfer (in SI Units) (SIE)
This hallmark text on Heat Transfer presents an elementary and classical treatment of principles of heat transfer With emphasis on physical understanding while relying on meaningful experimental data.
Key Features:

Analytical and Numerical treatment of Conduction-to gain insight into important tools of numerical analysis used in practice. (Chapter 2-4) Integral analysis of both free and forced convection boundary layers is used to present a physical picture of convection process. (Chapters 5-7) Heat Exchangers: Log mean temperature difference and effectiveness approaches are discussed. (Chapter 10) Important analogies between heat, mass and momentum transfer are discussed through a brief introduction to diffusion and mass transfer in chapter 11. Design is highlighted with over 100 open ended, design oriented homework problems. Emphasis on resistance capacity formulation in computer numerical methods. Large number of numerical examples on heat sources, radiation boundary conditions, non uniform mesh size and 3D nodal systems.

Table of Content:


Chapter 1. Introduction
Chapter 2. Steady-State Conduction-One Dimension
Chapter 3. Steady-State Conduction-Multiple Dimension
Chapter 4. Unsteady-State Conduction
Chapter 5. Principles of Convection
Chapter 6. Empirical and Practical Relation for Forced-Convection Heat Transfer
Chapter 7. Natural Convection Systems
Chapter 8. Radiation Heat Transfer
Chapter 9. Condensation and Boiling Heat Transfer
Chapter 10. Heat Exchange
Chapter 11. Mass Transfer
A. Tables
B. Exact Solutions of Laminar-Boundary-Layer Equations
C. Analytical Relations for the Heisler Charts
D. Use of Microsoft Excel for Solution of Heat- Transfer Problems