Homework Help is Here – Start Your Trial Now!
Engineering
Chemical Engineering
2. A 5 cm-thick beef steak is being frozen in a -30°C room. The product has 73% moisture content, a density of 970 kg/m 3, and thermal conductivity (frozen) of 1.1 W/(m K). Estimate the freezing time using Plank's equation. The product has an initial freezing temperature of -75°C, and the movement of air in the freezing room provides a convective heat-transfer coefficient of 5 W/(m 2 K).

2. A 5 cm-thick beef steak is being frozen in a -30°C room. The product has 73% moisture content, a density of 970 kg/m 3, and thermal conductivity (frozen) of 1.1 W/(m K). Estimate the freezing time using Plank's equation. The product has an initial freezing temperature of -75°C, and the movement of air in the freezing room provides a convective heat-transfer coefficient of 5 W/(m 2 K).

Introduction to Chemical Engineering Thermodynamics
Introduction to Chemical Engineering Thermodynamics
8th Edition
ISBN:9781259696527
Author:J.M. Smith Termodinamica en ingenieria quimica, Hendrick C Van Ness, Michael Abbott, Mark Swihart
Publisher:J.M. Smith Termodinamica en ingenieria quimica, Hendrick C Van Ness, Michael Abbott, Mark Swihart
Chapter1: Introduction
Section: Chapter Questions
Problem 1.1P
See similar textbooks
icon
Related questions
Question
**Problem Statement:** A 5 cm-thick beef steak is being frozen in a -30°C room. The product has 73% moisture content, a density of 970 kg/m³, and a thermal conductivity (frozen) of 1.1 W/(m·K). Estimate the freezing time using Plank’s equation. The product has an initial freezing temperature of -75°C, and the movement of air in the freezing room provides a convective heat-transfer coefficient of 5 W/(m²·K). **Solution Approach:** To solve this problem, we will use Plank’s equation, which is commonly applied in food processing to estimate the freezing time of products. We need to calculate the time required to freeze the given beef steak based on its properties and the environmental conditions provided. 1. **Assumptions:** - The steak is uniformly 5 cm thick. - The freezer has a constant temperature of -30°C. - The properties provided (density, thermal conductivity, and moisture content) remain constant during the process. 2. **Variables:** - Thickness (L) = 5 cm = 0.05 m - Temperature of the room (T_r) = -30°C - Initial freezing temperature (T_i) = -75°C - Density (ρ) = 970 kg/m³ - Thermal conductivity (k) = 1.1 W/(m·K) - Moisture content = 73% - Convective heat-transfer coefficient (h) = 5 W/(m²·K) 3. **Plank’s Freezing Time Equation:** - Plank’s equation will be applied, which generally includes the properties and dimensions of the product, along with the temperature difference and cooling conditions. The goal is to substitute the known values into Plank’s equation and calculate the freezing time, ensuring all units are consistent.
Transcribed Image Text:**Problem Statement:** A 5 cm-thick beef steak is being frozen in a -30°C room. The product has 73% moisture content, a density of 970 kg/m³, and a thermal conductivity (frozen) of 1.1 W/(m·K). Estimate the freezing time using Plank’s equation. The product has an initial freezing temperature of -75°C, and the movement of air in the freezing room provides a convective heat-transfer coefficient of 5 W/(m²·K). **Solution Approach:** To solve this problem, we will use Plank’s equation, which is commonly applied in food processing to estimate the freezing time of products. We need to calculate the time required to freeze the given beef steak based on its properties and the environmental conditions provided. 1. **Assumptions:** - The steak is uniformly 5 cm thick. - The freezer has a constant temperature of -30°C. - The properties provided (density, thermal conductivity, and moisture content) remain constant during the process. 2. **Variables:** - Thickness (L) = 5 cm = 0.05 m - Temperature of the room (T_r) = -30°C - Initial freezing temperature (T_i) = -75°C - Density (ρ) = 970 kg/m³ - Thermal conductivity (k) = 1.1 W/(m·K) - Moisture content = 73% - Convective heat-transfer coefficient (h) = 5 W/(m²·K) 3. **Plank’s Freezing Time Equation:** - Plank’s equation will be applied, which generally includes the properties and dimensions of the product, along with the temperature difference and cooling conditions. The goal is to substitute the known values into Plank’s equation and calculate the freezing time, ensuring all units are consistent.
Expert Solution
steps

Step by step

Solved in 2 steps with 2 images

SEE SOLUTIONCheck out a sample Q&A here
Blurred answer
Similar questions
Recommended textbooks for you
Introduction to Chemical Engineering Thermodynami…
Introduction to Chemical Engineering Thermodynami…
Chemical Engineering
ISBN:
9781259696527
Author:
J.M. Smith Termodinamica en ingenieria quimica, Hendrick C Van Ness, Michael Abbott, Mark Swihart
Publisher:
McGraw-Hill Education
Elementary Principles of Chemical Processes, Bind…
Elementary Principles of Chemical Processes, Bind…
Chemical Engineering
ISBN:
9781118431221
Author:
Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
Publisher:
WILEY
Elements of Chemical Reaction Engineering (5th Ed…
Elements of Chemical Reaction Engineering (5th Ed…
Chemical Engineering
ISBN:
9780133887518
Author:
H. Scott Fogler
Publisher:
Prentice Hall
Process Dynamics and Control, 4e
Process Dynamics and Control, 4e
Chemical Engineering
ISBN:
9781119285915
Author:
Seborg
Publisher:
WILEY
Industrial Plastics: Theory and Applications
Industrial Plastics: Theory and Applications
Chemical Engineering
ISBN:
9781285061238
Author:
Lokensgard, Erik
Publisher:
Delmar Cengage Learning
Unit Operations of Chemical Engineering
Unit Operations of Chemical Engineering
Chemical Engineering
ISBN:
9780072848236
Author:
Warren McCabe, Julian C. Smith, Peter Harriott
Publisher:
McGraw-Hill Companies, The
SEE MORE TEXTBOOKS