Heating and Cooling of Agitated Liquid Batches: Isothermal Medium - a PDH Online Course for Engineers and Surveyors

Heating and Cooling of Agitated Liquid Batches: Isothermal Medium

Course Outline

There are many industrial instances whereby it is desirable to know the time required to heat or cool a volume of liquid that is being agitated in a tank or reactor vessel. This three hour course will focus on deriving the application equations for calculating the time, _hours, required to heat or cool an agitated liquid volume of mass M_batch from an initial temperature of T_initial to T_final. The heating or cooling medium to be used will be under isothermal conditions, defined as T_heat or T_cool. By definition then, the inlet and outlet temperature of the heating and/or cooling medium will be the same. An equation is derived for both heating and cooling applications.

Following the derivation of the application equations, two industrial examples will be given. The first is a steam supplied jacketed vessel used to heat an agitated batch of cold water, and, the second, a refrigerant submerged coil in a tank used to cool an agitated batch of hot water.

This course includes a True-False quiz at the end.

Learning Objective

It is the intention of this course to enable process engineers or plant operations personnel to be able to calculate the time required to heat or cool an agitated liquid batch with a minimum of effort. The course will explain the derivation of the heating and cooling application equations, along with simplifying assumptions. Two examples are given: heating in a jacketed agitated vessel, and cooling with a submerged coil in an agitated tank. At the conclusion of the course the student will:

Have an understanding of simplified batch heat transfer relationships within a well mixed tank.
Be knowledgeable in the assumptions used to calculate batch heat transfer relationships.
Be able to calculate batch heating and cooling requirements with isothermal heating or cooling mediums.

Course Introduction

This course provides the student with application equations that allow for calculating the transient time required for heating and cooling of liquid batches from an initial temperature to a final temperature. The course will derive the application equations from a differential heat balance. Several simplifying assumptions are utilized which result in an exact solution of the integrated form of the differential heat balance equation.

Course Content

The course content is in a PDF file (80 KB) Isothermal Medium.pdf. You need to open or download this document to study this course.

Course Summary

The course developed the derivation of the heating and cooling application equations, along with simplifying assumptions. Two examples were given: heating in a jacketed agitated vessel, and cooling with a submerged coil in an agitated tank. The physical property data required for the examples consisted of readily available information: an average batch liquid density, an average batch liquid heat capacity, saturation temperatures of the heating and cooling mediums used. At the conclusion of the course, the student should:

Have an understanding of simplified batch heat transfer relationships within a well mixed tank.
Be knowledgeable in the assumptions used to calculate batch heat transfer relationships.
Be able to calculate batch heating and cooling requirements with isothermal heating or cooling mediums.

Related References

1. Kern, Donald Q., Process Heat Transfer, McGraw-Hill Book Company, New York, 1950, pp.624-26, and 717-21.
2. McCabe, Warren L. and Julian C. Smith, Unit Operations of Chemical Engineering, McGraw-Hill Book Company, New York, 3^rd ed., 1976, pp. 222-23, and 421-23.
3. Perry, Robert H. and Cecil H. Chilton, Chemical Engineer's Handbook, McGraw -Hill Book Company, New York, 5^th ed., 1973, pp. 3-129, 4-37.
4. Foust, Alan S. et. al., Principles of Unit Operations, John Wiley & Sons, New York, 1960, p. 228.
5. Himmelblau, David M., Basic Principles and Calculations in Chemical Engineering, Prentice-Hall, Inc., Englewood Cliffs, NJ, 1967, Appendix C: Steam Tables.
6. Jennings, Burgess H., The Thermal Environment: Conditioning and Control, Harper & Row, New York, 1978, p. 525.

Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.

DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDHonline.com or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered professional engineer. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.