This document discusses evaporation processes and equipment. It begins by defining evaporation as adding heat to a solution to vaporize the solvent, usually water, and describes factors that affect evaporation processing like concentration, solubility, temperature, and foaming. It then covers types of evaporation equipment like single-effect and multiple-effect evaporators. For single-effect evaporators, it provides methods to calculate vapor and liquid flowrates, heat transfer area, and heat transfer coefficient. For multiple-effect evaporators, it notes they allow the latent heat of vapor from earlier effects to be recovered and reused.
This document discusses a project on studying the steam economy of a multiple effect evaporator plant that produces sodium sulfate. It is a report submitted by 4 students to fulfill their Bachelor of Engineering degree requirements. The project aims to determine why steam utility increases over time in the plant's multiple effect evaporator for sodium sulfate production and find a suitable solution to reduce it. It will also involve simulating the multiple effect evaporator process using Excel. The document provides background on evaporators, multiple effect evaporators, sodium sulfate and its applications.
The document discusses evaporator performance and factors that affect it. It explains that the boiling point of solutions is higher than water alone, known as boiling point elevation. It also discusses how capacity, economy, and steam consumption are measures of evaporator performance. Capacity is the amount of water vaporized per hour, economy is the amount vaporized per unit of steam, and steam consumption can be estimated from capacity and economy. Duhring's rule and boiling point elevation must be considered for heat transfer calculations in evaporators dealing with solutions.
The document discusses evaporation processes and evaporator equipment. It defines evaporation as the removal of water from an aqueous solution through the application of heat. It then describes the types of evaporators, including single effect, multiple effect, forced circulation, open pan, and falling film evaporators. The document also covers important processing factors in evaporation like concentration, solubility, temperature, foaming, and scale deposition. It provides examples of calculating heat transfer area and steam usage for single effect evaporators concentrating different solutions.
This document summarizes information about multiple effect evaporators. It discusses that multiple effect evaporators use less energy than single effect evaporators by cascading the vapor from one evaporator to heat the next. It provides details on the design, operation, advantages and disadvantages of multiple effect evaporators. New aspects discussed include using various energy reduction schemes to reduce steam consumption, such as condensate flashing and vapor bleeding.
The document discusses various types of evaporators used to concentrate liquid solutions. It describes key properties that affect evaporation like concentration, solubility, temperature sensitivity, and foaming. The main types of evaporators covered are open kettle, horizontal natural circulation, vertical natural circulation, long tube vertical, falling film, forced circulation, agitated film, and open pan solar. Operation methods like single effect and multiple effect (forward feed, backward feed, parallel feed, mixed feed) are also summarized. Processing variables like temperature, pressure, and steam pressure that impact evaporator size and cost are outlined.
This document defines evaporator concepts like steam economy, evaporator capacity, and steam consumption. It describes single effect evaporators, where vapor from boiling liquid is condensed and discarded, resulting in low steam economy. Multiple effect evaporators improve steam economy by using vapor from one effect to heat the next. Forward, backward, mixed, and parallel feeding arrangements are described for transferring liquid between multiple effects. Forward feed provides increasing concentration from first to last effect without pumps between effects.
Gas absorption is a process used to separate gases by contacting a gas mixture with a liquid solvent. The key principles are the solubility of the absorbed gas and the rate of mass transfer as the gas dissolves into the liquid. Absorption is usually carried out counter-currently in vertical columns. The solvent is fed at the top while the gas enters at the bottom, allowing the absorbed substances to be washed out in the downward flowing liquid. Proper selection of solvent considers factors like gas solubility, volatility, cost, and viscosity. Rate of absorption is determined by volumetric mass transfer coefficients, which can be calculated from operating line and equilibrium curve diagrams.
This document discusses a project on studying the steam economy of a multiple effect evaporator plant that produces sodium sulfate. It is a report submitted by 4 students to fulfill their Bachelor of Engineering degree requirements. The project aims to determine why steam utility increases over time in the plant's multiple effect evaporator for sodium sulfate production and find a suitable solution to reduce it. It will also involve simulating the multiple effect evaporator process using Excel. The document provides background on evaporators, multiple effect evaporators, sodium sulfate and its applications.
The document discusses evaporator performance and factors that affect it. It explains that the boiling point of solutions is higher than water alone, known as boiling point elevation. It also discusses how capacity, economy, and steam consumption are measures of evaporator performance. Capacity is the amount of water vaporized per hour, economy is the amount vaporized per unit of steam, and steam consumption can be estimated from capacity and economy. Duhring's rule and boiling point elevation must be considered for heat transfer calculations in evaporators dealing with solutions.
The document discusses evaporation processes and evaporator equipment. It defines evaporation as the removal of water from an aqueous solution through the application of heat. It then describes the types of evaporators, including single effect, multiple effect, forced circulation, open pan, and falling film evaporators. The document also covers important processing factors in evaporation like concentration, solubility, temperature, foaming, and scale deposition. It provides examples of calculating heat transfer area and steam usage for single effect evaporators concentrating different solutions.
This document summarizes information about multiple effect evaporators. It discusses that multiple effect evaporators use less energy than single effect evaporators by cascading the vapor from one evaporator to heat the next. It provides details on the design, operation, advantages and disadvantages of multiple effect evaporators. New aspects discussed include using various energy reduction schemes to reduce steam consumption, such as condensate flashing and vapor bleeding.
The document discusses various types of evaporators used to concentrate liquid solutions. It describes key properties that affect evaporation like concentration, solubility, temperature sensitivity, and foaming. The main types of evaporators covered are open kettle, horizontal natural circulation, vertical natural circulation, long tube vertical, falling film, forced circulation, agitated film, and open pan solar. Operation methods like single effect and multiple effect (forward feed, backward feed, parallel feed, mixed feed) are also summarized. Processing variables like temperature, pressure, and steam pressure that impact evaporator size and cost are outlined.
This document defines evaporator concepts like steam economy, evaporator capacity, and steam consumption. It describes single effect evaporators, where vapor from boiling liquid is condensed and discarded, resulting in low steam economy. Multiple effect evaporators improve steam economy by using vapor from one effect to heat the next. Forward, backward, mixed, and parallel feeding arrangements are described for transferring liquid between multiple effects. Forward feed provides increasing concentration from first to last effect without pumps between effects.
Gas absorption is a process used to separate gases by contacting a gas mixture with a liquid solvent. The key principles are the solubility of the absorbed gas and the rate of mass transfer as the gas dissolves into the liquid. Absorption is usually carried out counter-currently in vertical columns. The solvent is fed at the top while the gas enters at the bottom, allowing the absorbed substances to be washed out in the downward flowing liquid. Proper selection of solvent considers factors like gas solubility, volatility, cost, and viscosity. Rate of absorption is determined by volumetric mass transfer coefficients, which can be calculated from operating line and equilibrium curve diagrams.
The document discusses multiple effect evaporators, which are used to efficiently concentrate solutions by removing solvent, mainly water, through evaporation. It explains that multiple effect evaporators use heat from steam to evaporate water in multiple stages, making the process more economical than single effect evaporators. Multiple effect evaporators are divided into three categories based on feed direction: forward feed, backward feed, and mixed feed. They have various applications like product concentration, solvent recovery, and crystallization. Key advantages include being an advanced system that is easy to operate and maintain cost effectively.
Heat exchangers transfer heat between two or more fluids. There are three main types: direct transfer, storage, and direct contact. Direct transfer type heat exchangers simultaneously flow hot and cold fluids through a separating wall. Storage type heat exchangers alternately flow hot and cold fluids through a porous matrix. Direct contact type heat exchangers do not separate the fluids. Common examples are plate heat exchangers and shell-and-tube heat exchangers. Design considerations include materials, operating parameters, fouling factors, and determining the required heat transfer area.
I found no good source for extractive distillation on the internet.So i decided to make one myself.This ppt discusses about the technology,its working and benefits.It compares extractive distillation side by side to azeotropic distillation and counts the advantages.
Introduction to multicomponent distillationSujeet TAMBE
This document provides an introduction and overview of multicomponent distillation processes. It discusses key concepts like key components, distributed vs. undistributed components, and challenges in designing multicomponent distillation columns compared to binary systems. The document then outlines the steps of the Fenske-Underwood-Gilliland short cut design method for solving multicomponent distillation problems, including calculating the minimum number of stages, minimum reflux ratio, actual number of stages, and feed stage location.
Evaporation involves removing water from liquids through heating. Factors like pressure, added solutes, and elevation affect boiling point. Common evaporator types include pans, circulation, film, and agitated thin-film designs. Capacity is measured by vapor produced while steam economy is the ratio of vapor to steam used. Multiple effects and vapor recompression can improve steam economy by cascading heat between stages or compressing vapor for reheating.
The document discusses evaporation as a process to remove water from dilute liquids to produce concentrated liquids. It describes how an evaporator uses a heat exchanger and vacuum chamber to boil liquids at low temperatures, minimizing heat damage. Various types of evaporators are covered, including single-effect, multiple-effect, batch, natural circulation, rising film, falling film, and forced circulation evaporators. Key factors that affect evaporation rates like heat transfer, boiling point, pressure, and changes to products are also summarized.
Evaporation and types of evaporators used in processing industries.Ram Tiwari
An evaporator is a device that uses heat to remove water from liquids through vaporization. There are several types of evaporators used in food processing, including batch pan evaporators, natural circulation evaporators, forced circulation evaporators, rising film evaporators, falling film evaporators, and rising/falling film evaporators. Each type uses a different design and configuration of heating elements and liquid flow to efficiently evaporate water out of foods and concentrates.
The document discusses evaporation as a unit operation used to concentrate solutions by removing water or other volatile solvent. It describes different types of evaporators used for this purpose, including batch pans, rising film evaporators, falling film evaporators, and multiple effect evaporators. The key components and working principles of evaporators are explained. Specific examples of evaporation applications are also provided.
Heat exchangers transfer heat from one fluid to another. There are two main types: tube-and-shell and plate. Tube-and-shell consists of tubes in a shell where fluids flow inside and outside the tubes. Plate heat exchangers use plates to separate fluids which flow between plates in alternating channels. Heat exchangers can operate in parallel, counter, or cross flow configurations. Performance tests determine the overall heat transfer coefficient and identify any fouling issues.
Steam and its properties and steam tableSACHINNikam39
Steam is water in its gaseous phase that is formed when water boils. There are three main types of steam: wet steam containing water droplets, dry saturated steam containing no water, and superheated steam which is heated above the saturation temperature. The properties of steam such as temperature, pressure, specific volume, enthalpy, and entropy vary depending on whether it is saturated, wet, or superheated steam. Steam tables contain values of these key thermodynamic properties at different pressures and are used for analyzing steam systems and cycles.
Aspen Plus basic course for Engineers.
Introduction to Process Modeling/Simulation Software.
INDEX:
Course Objectives
Introduction to Aspen Plus
User Interface & Getting Help
Physical Properties
Introduction to Flowsheet
Unit Operation Models
Reporting Results
Case Studies I, II and III
Case Study IV
Conclusion
Shell and Tube Heat Exchanger in heat TransferUsman Shah
Shell and tube heat exchangers consist of a bundle of tubes enclosed in a cylindrical shell. Fluids flow through either the tubes or shell to facilitate heat transfer between the two fluids. They are widely used in chemical processes due to their ability to achieve a large heat transfer surface area in a compact volume. Key components include tubesheets, baffles, support rods and segmented baffles which direct fluid flow across the tube bundle for efficient heat transfer. Design considerations include allocating the more corrosive or fouling fluid to the tubeside for easier cleaning and maintenance.
This document discusses distillation of binary mixtures. It begins by defining distillation as a process that separates a feed mixture into multiple products, often an overhead distillate and a bottoms product, using the differences in volatility between components. The key design factors for distillation include feed composition, desired separation, operating pressure, reflux ratio, number of stages, condenser/reboiler type, and column internals. Vapor-liquid equilibrium concepts like relative volatility and Raoult's law determine the feasibility of separation. Single-stage processes like flash distillation, simple batch distillation, and steam distillation are also introduced.
General Knowledge on Ammonia Production By Prem Baboo.pdfPremBaboo4
The present paper description of Ammonia Plant, Production of Green Hydrogen, Different types of revamp option of Ammonia & urea plant different types of ammonia process, calculation. This paper is very useful for Engineering students, new comers in fertilizers Industries .Practical data detail of vessel, Electric heating primary reformer and what is the difference of Gas fired primary reformer and Electric heating, calculation, efficiency etc.
This document provides lecture notes on mass and energy balances. It covers key topics such as dimensions, units, unit conversion, material balances, and energy balances. Chapter 1 defines dimensions, units, and common unit systems used in engineering. It explains how to perform unit conversions and check the dimensional homogeneity of equations. Later chapters discuss using material and energy balances to analyze processes involving multiple units and unit operations.
spray drying is technology widely used in milk powder and coffee powder manufacturing industry because of its working principle and technology involved..
This document discusses operating pre-reformers at high temperatures and the associated benefits and drawbacks. It notes that while higher temperatures allow for better thermal efficiency and feedstock flexibility in reformers, they can also cause hydrothermal sintering of catalysts over time from high heat and steam. The document provides guidelines for startup, reduction, and operation of pre-reformer catalysts to maximize performance while mitigating sintering risks.
1) Distillation is a method used to separate components of a liquid solution based on differences in how the components distribute between the vapor and liquid phases when heated to their boiling points.
2) Raoult's law describes vapor-liquid equilibrium for ideal solutions, relating the partial pressure of a component in vapor phase to its mole fraction in the liquid phase. Boiling point diagrams can be constructed using vapor pressure data.
3) Equilibrium or flash distillation involves heating a liquid mixture to partially vaporize it in a single stage, separating the vapor and liquid which approach equilibrium compositions.
This document discusses various types of equipment used for mass transfer operations in industry. It describes plate columns and packed columns as the two most widely used for distillation, gas absorption, and stripping. Plate columns are also known as tray columns, where the column is divided into stages by trays. The main types of trays are sieve, bubble-cap, and valve trays. Packed columns can use random, structured, or grid packings. Other equipment discussed include bubble columns, spray columns, and agitated vessels. Selection of mass transfer equipment depends on the process conditions and economics.
Bab 4 - Perhitungan Single effect evaporator.pptxrudi prihantoro
The document discusses the calculation of a single effect evaporator. It provides the equations for material and heat balance calculations. An example calculation is shown for an evaporator concentrating a 1% salt solution. The key parameters calculated are the vapor and liquid outputs, and the required heat transfer area. Operational factors like feed temperature, pressure, and boiling point rise are also discussed.
This document discusses the thermal design of a simple boiler. It presents the calculation procedures for boiler design, focusing on heat transfer modes, heat and mass balances, and a worked example. The key points are:
- Heat transfer in boilers occurs via conduction, convection, and radiation. Conduction is not considered in simple calculations.
- Heat and mass balance equations relate the heat input from fuel to the heat output via steam as well as accounting for air and flue gas flows.
- A worked example calculates furnace conditions like flue gas temperature for a methane-fueled boiler, assuming radiation is the only heat transfer mode in the furnace. Tube bank calculations then determine the exit gas
The document discusses multiple effect evaporators, which are used to efficiently concentrate solutions by removing solvent, mainly water, through evaporation. It explains that multiple effect evaporators use heat from steam to evaporate water in multiple stages, making the process more economical than single effect evaporators. Multiple effect evaporators are divided into three categories based on feed direction: forward feed, backward feed, and mixed feed. They have various applications like product concentration, solvent recovery, and crystallization. Key advantages include being an advanced system that is easy to operate and maintain cost effectively.
Heat exchangers transfer heat between two or more fluids. There are three main types: direct transfer, storage, and direct contact. Direct transfer type heat exchangers simultaneously flow hot and cold fluids through a separating wall. Storage type heat exchangers alternately flow hot and cold fluids through a porous matrix. Direct contact type heat exchangers do not separate the fluids. Common examples are plate heat exchangers and shell-and-tube heat exchangers. Design considerations include materials, operating parameters, fouling factors, and determining the required heat transfer area.
I found no good source for extractive distillation on the internet.So i decided to make one myself.This ppt discusses about the technology,its working and benefits.It compares extractive distillation side by side to azeotropic distillation and counts the advantages.
Introduction to multicomponent distillationSujeet TAMBE
This document provides an introduction and overview of multicomponent distillation processes. It discusses key concepts like key components, distributed vs. undistributed components, and challenges in designing multicomponent distillation columns compared to binary systems. The document then outlines the steps of the Fenske-Underwood-Gilliland short cut design method for solving multicomponent distillation problems, including calculating the minimum number of stages, minimum reflux ratio, actual number of stages, and feed stage location.
Evaporation involves removing water from liquids through heating. Factors like pressure, added solutes, and elevation affect boiling point. Common evaporator types include pans, circulation, film, and agitated thin-film designs. Capacity is measured by vapor produced while steam economy is the ratio of vapor to steam used. Multiple effects and vapor recompression can improve steam economy by cascading heat between stages or compressing vapor for reheating.
The document discusses evaporation as a process to remove water from dilute liquids to produce concentrated liquids. It describes how an evaporator uses a heat exchanger and vacuum chamber to boil liquids at low temperatures, minimizing heat damage. Various types of evaporators are covered, including single-effect, multiple-effect, batch, natural circulation, rising film, falling film, and forced circulation evaporators. Key factors that affect evaporation rates like heat transfer, boiling point, pressure, and changes to products are also summarized.
Evaporation and types of evaporators used in processing industries.Ram Tiwari
An evaporator is a device that uses heat to remove water from liquids through vaporization. There are several types of evaporators used in food processing, including batch pan evaporators, natural circulation evaporators, forced circulation evaporators, rising film evaporators, falling film evaporators, and rising/falling film evaporators. Each type uses a different design and configuration of heating elements and liquid flow to efficiently evaporate water out of foods and concentrates.
The document discusses evaporation as a unit operation used to concentrate solutions by removing water or other volatile solvent. It describes different types of evaporators used for this purpose, including batch pans, rising film evaporators, falling film evaporators, and multiple effect evaporators. The key components and working principles of evaporators are explained. Specific examples of evaporation applications are also provided.
Heat exchangers transfer heat from one fluid to another. There are two main types: tube-and-shell and plate. Tube-and-shell consists of tubes in a shell where fluids flow inside and outside the tubes. Plate heat exchangers use plates to separate fluids which flow between plates in alternating channels. Heat exchangers can operate in parallel, counter, or cross flow configurations. Performance tests determine the overall heat transfer coefficient and identify any fouling issues.
Steam and its properties and steam tableSACHINNikam39
Steam is water in its gaseous phase that is formed when water boils. There are three main types of steam: wet steam containing water droplets, dry saturated steam containing no water, and superheated steam which is heated above the saturation temperature. The properties of steam such as temperature, pressure, specific volume, enthalpy, and entropy vary depending on whether it is saturated, wet, or superheated steam. Steam tables contain values of these key thermodynamic properties at different pressures and are used for analyzing steam systems and cycles.
Aspen Plus basic course for Engineers.
Introduction to Process Modeling/Simulation Software.
INDEX:
Course Objectives
Introduction to Aspen Plus
User Interface & Getting Help
Physical Properties
Introduction to Flowsheet
Unit Operation Models
Reporting Results
Case Studies I, II and III
Case Study IV
Conclusion
Shell and Tube Heat Exchanger in heat TransferUsman Shah
Shell and tube heat exchangers consist of a bundle of tubes enclosed in a cylindrical shell. Fluids flow through either the tubes or shell to facilitate heat transfer between the two fluids. They are widely used in chemical processes due to their ability to achieve a large heat transfer surface area in a compact volume. Key components include tubesheets, baffles, support rods and segmented baffles which direct fluid flow across the tube bundle for efficient heat transfer. Design considerations include allocating the more corrosive or fouling fluid to the tubeside for easier cleaning and maintenance.
This document discusses distillation of binary mixtures. It begins by defining distillation as a process that separates a feed mixture into multiple products, often an overhead distillate and a bottoms product, using the differences in volatility between components. The key design factors for distillation include feed composition, desired separation, operating pressure, reflux ratio, number of stages, condenser/reboiler type, and column internals. Vapor-liquid equilibrium concepts like relative volatility and Raoult's law determine the feasibility of separation. Single-stage processes like flash distillation, simple batch distillation, and steam distillation are also introduced.
General Knowledge on Ammonia Production By Prem Baboo.pdfPremBaboo4
The present paper description of Ammonia Plant, Production of Green Hydrogen, Different types of revamp option of Ammonia & urea plant different types of ammonia process, calculation. This paper is very useful for Engineering students, new comers in fertilizers Industries .Practical data detail of vessel, Electric heating primary reformer and what is the difference of Gas fired primary reformer and Electric heating, calculation, efficiency etc.
This document provides lecture notes on mass and energy balances. It covers key topics such as dimensions, units, unit conversion, material balances, and energy balances. Chapter 1 defines dimensions, units, and common unit systems used in engineering. It explains how to perform unit conversions and check the dimensional homogeneity of equations. Later chapters discuss using material and energy balances to analyze processes involving multiple units and unit operations.
spray drying is technology widely used in milk powder and coffee powder manufacturing industry because of its working principle and technology involved..
This document discusses operating pre-reformers at high temperatures and the associated benefits and drawbacks. It notes that while higher temperatures allow for better thermal efficiency and feedstock flexibility in reformers, they can also cause hydrothermal sintering of catalysts over time from high heat and steam. The document provides guidelines for startup, reduction, and operation of pre-reformer catalysts to maximize performance while mitigating sintering risks.
1) Distillation is a method used to separate components of a liquid solution based on differences in how the components distribute between the vapor and liquid phases when heated to their boiling points.
2) Raoult's law describes vapor-liquid equilibrium for ideal solutions, relating the partial pressure of a component in vapor phase to its mole fraction in the liquid phase. Boiling point diagrams can be constructed using vapor pressure data.
3) Equilibrium or flash distillation involves heating a liquid mixture to partially vaporize it in a single stage, separating the vapor and liquid which approach equilibrium compositions.
This document discusses various types of equipment used for mass transfer operations in industry. It describes plate columns and packed columns as the two most widely used for distillation, gas absorption, and stripping. Plate columns are also known as tray columns, where the column is divided into stages by trays. The main types of trays are sieve, bubble-cap, and valve trays. Packed columns can use random, structured, or grid packings. Other equipment discussed include bubble columns, spray columns, and agitated vessels. Selection of mass transfer equipment depends on the process conditions and economics.
Bab 4 - Perhitungan Single effect evaporator.pptxrudi prihantoro
The document discusses the calculation of a single effect evaporator. It provides the equations for material and heat balance calculations. An example calculation is shown for an evaporator concentrating a 1% salt solution. The key parameters calculated are the vapor and liquid outputs, and the required heat transfer area. Operational factors like feed temperature, pressure, and boiling point rise are also discussed.
This document discusses the thermal design of a simple boiler. It presents the calculation procedures for boiler design, focusing on heat transfer modes, heat and mass balances, and a worked example. The key points are:
- Heat transfer in boilers occurs via conduction, convection, and radiation. Conduction is not considered in simple calculations.
- Heat and mass balance equations relate the heat input from fuel to the heat output via steam as well as accounting for air and flue gas flows.
- A worked example calculates furnace conditions like flue gas temperature for a methane-fueled boiler, assuming radiation is the only heat transfer mode in the furnace. Tube bank calculations then determine the exit gas
Module 1
Steam Engineering: Properties of steam - wet, dry and superheated steam -
dryness fraction - enthalpy and internal energy - entropy of steam - temperature
entropy diagram - process - Mollier chart - Rankine cycle for wet, dry and
superheated steam. Steam Generators - classification - modern steam generators -
boiler mountings and accessories.
Module 2
Steam nozzles - Mass flow rate - throat pressure for maximum discharge - throat
area - effect of friction - super saturated flow.
Steam turbines: velocity triangles, work done, governing, and efficiencies.
Module 3
Gas turbine Plants - Open and closed cycles - thermodynamics cycles -
regeneration, re heating - inter cooling - efficiency and performance of gas
turbines. Rotary Compressors - Analysis of rotary compressors - centrifugal and
axial compressors. Combustion - combustion chambers of gas turbines -
cylindrical, annular and industrial type combustion chamber - combustion
intensity - combustion chambers efficiency - pressure loss combustion process
and stability loop.
Module 4
Introduction to solar energy - solar collectors - Liquid flat plate collectors -
principle - thermal losses and efficiency - characteristics - overall loss coefficient
- thermal analysis - useful heat gained by fluid - mean plate temperature -
performance - focussing type solar collectors - solar concentrators and receivers
- sun tracking system - characteristics - optical losses - thermal performance -
solar pond - solar water heating - solar thermal power generation
Module 5
Thermal power plants: layout and operation of steam and diesel power plants - coal
burners - stockers - cooling ponds & towers - chimneys - draught - dust collectors -
precipitators - feed water heaters - evaporators - steam condensers - coal handling - ash
handling
Thermodynamics chapter discusses properties of liquids and vapors including:
- Constant pressure process where boiling occurs at a fixed temperature for a given pressure.
- Saturation temperature is the boiling point corresponding to a pressure.
- Quality is the dryness fraction of wet steam.
- Tabulated properties include values for saturated water, steam, compressed water, wet steam and superheated steam.
- Constant pressure, constant volume, isothermal, adiabatic and polytropic processes are examined for non-flow systems involving changes to steam.
Module 5 (properties of pure substance)2021 2022Yuri Melliza
This document discusses properties of pure substances and steam. It defines key terms like saturation temperature, saturation pressure, subcooled liquid, compressed liquid, saturated mixture, and superheated vapor. It also describes temperature-specific volume, temperature-entropy, and enthalpy-entropy diagrams. Sample problems are provided to calculate properties like quality, enthalpy, specific volume, power output, and mass flow rate using steam tables and the concepts introduced.
Solution Manual for Physical Chemistry – Robert AlbertyHenningEnoksen
https://www.book4me.xyz/solution-manual-physical-chemistry-alberty/
Solution Manual for Physical Chemistry - 6th Edition
Author(s) : Robert A. Alberty
This solution manual include all chapters of textbook (1 to 21).
- The document describes an evaporator that concentrates a 20% sodium hydroxide solution to 50% using steam at a temperature of 126.45°C.
- Key calculations include determining vapor and liquid temperatures and enthalpies, solving material and energy balances, and using the heat transfer equation to calculate the required vapor flow.
- Solving the system of equations gives the feed rate F to the evaporator as 11,700 kg/h.
This document describes the Rankine cycle, which is commonly used in steam power plants. It consists of four processes:
1. Constant pressure heat addition in a boiler, heating water to steam.
2. Adiabatic expansion of the steam in a turbine, producing work.
3. Constant pressure heat rejection in a condenser, condensing the steam to water.
4. Adiabatic compression of the water in a pump, returning it to the boiler pressure.
The efficiency of the Rankine cycle depends on the temperature difference between the steam entering and leaving the turbine. Examples are provided to illustrate efficiency calculations for Rankine cycles operating between different pressure and temperature conditions.
The document discusses properties of pure substances and phases of matter. It defines key terms like boiling point, melting point, saturation point, saturation pressure, saturation temperature, and triple point. It also discusses properties of steam like wet steam, dry saturated steam, superheated steam, and dryness fraction. Expressions are provided for enthalpy, internal energy, specific volume of different types of steam. Steam tables listing temperature, pressure, specific volume, enthalpy and entropy values are also included. The Rankine cycle used in steam engines is briefly explained through its four processes of heat addition, expansion, heat rejection and pumping.
This document summarizes the content of lectures on evaporation processes, including factors affecting evaporation, types of evaporators, and mathematical problems involving evaporation. It provides an example problem calculating requirements for a triple effect evaporator, including steam needs, heat transfer areas, evaporating temperatures in each effect, and steam economy. It also discusses optimizing the boiling time to maximize throughput or minimize costs by balancing heat transfer rate reductions from scale buildup with shutdown frequencies.
The document discusses steam power plant cycles. It begins by introducing the Rankine cycle as the ideal cycle for steam power plants. The Rankine cycle involves isothermal heat addition in a boiler, isentropic expansion in a turbine, isothermal heat rejection in a condenser, and isentropic compression in a pump. The document then discusses ways to increase the efficiency of the Rankine cycle, including lowering the condenser pressure, superheating steam to higher temperatures, increasing the boiler pressure, and adding reheat stages. Reheating steam between turbine stages allows higher boiler pressures without excessive moisture at the turbine exit. The ideal reheat Rankine cycle provides higher efficiency than a simple Rankine cycle.
The document defines key terms related to steam power plants, including saturation temperature, dryness fraction, enthalpy of vaporization, and superheated vapor. It then describes the ideal Rankine cycle, which consists of four processes: isentropic expansion in a turbine, constant pressure heat rejection in a condenser, isentropic compression in a pump, and constant pressure heat addition in a boiler. Deviations from the ideal cycle include irreversibilities from fluid friction and heat loss. Methods to increase the efficiency of the Rankine cycle include lowering the condenser pressure, superheating the steam, increasing the boiler pressure, and using reheat cycles.
This document discusses the properties of steam. It begins by defining steam as the gaseous phase of water produced by heating water. Steam can exist in different states such as wet steam, dry saturated steam, and superheated steam. The document then discusses the enthalpy, specific volume, internal energy, and dryness fraction of different types of steam. It concludes by explaining different types of calorimeters used to measure the dryness fraction of steam, including barrel, separating, throttling, and combined separating and throttling calorimeters.
This document discusses various thermodynamic power cycles including:
- The Carnot cycle, which is the most efficient but impractical cycle.
- Rankine cycles, which are more practical vapor power cycles that use steam as the working fluid.
- Simple Rankine cycles involve heating water to steam then expanding it in a turbine before condensing it back to water.
- Rankine cycles with superheated steam, which increase efficiency by heating steam above its saturation temperature.
- The efficiencies of different cycles are calculated and compared in examples. Superheated steam cycles have higher efficiencies than simple Rankine cycles due to higher average temperatures.
This document discusses different thermodynamic processes and properties of steam. It defines four main cyclic processes: isochoric, isobaric, isothermal, and adiabatic. It then explains the characteristics of each process and provides examples of their P-V graphs. The document also discusses key steam properties like saturation temperature, dryness fraction, latent heat of vaporization, and enthalpy. It introduces the Mollier chart and how to use it to calculate enthalpy values for wet, dry, and superheated steam at different conditions. Worked examples are provided to demonstrate using steam tables and the Mollier chart.
The document contains solutions to several problems involving thermodynamic cycles and processes. It calculates things like:
- Water flow and power output for a hydroelectric plant given head, efficiency and installed capacity.
- Power output, heat loss and efficiencies for a turbine given inputs like flow rate, head, and efficiencies.
- Exhaust properties like temperature, enthalpy and quality for steam turbines given inlet conditions and pressures.
- Parameters like work, efficiency and temperatures for Rankine cycles and gas turbine cycles.
Heat/light/electrical energy is out today’s necessity and has scarcity also. Energy conservation is key requirement of any industry at all times.
In general, industries use heat energy for conservation of raw material to finished product. The source of heat energy is generally saturated or super heated steam. The steam generation is common use one boiler with carity of fuels. Whatever may be the fuel the generation should be as economy as possible which adds to the product cost. Further the usage of steam and recycling steam condensate back to boiler is an art depending on plant layouts.
In this project the steam generator is water tube boiler fired with rice husk. The steam is transferred to the tyre/tube moulds where tyres/tubes are cured while the heat is rejected to the tyres the condensate forms and this condensate is put back to the boiler. While doing so the steam is also stopped back to boiler without rejecting complete heat to the product. This gets flashed into atmosphere at feed water tank. The science of separation of condensate from steam saves energy. Better the separation more the fuel conservation.
In the steam generator the fuel is burnt to heat the water and form steam. This fuel burnt flue gas carries lot of energy, out through chimney. Prior to exhausting through the heat left in flue need to be recovered, through heat recovery mechanisms’. In this project an air-preheater condensate heat recovery unit is the major energy consuming station.
The document summarizes key gas laws including Boyle's law, Charles' law, Avogadro's law, Dalton's law of partial pressures, and the ideal gas law. It provides examples of using these laws to calculate volume, pressure, temperature, moles, and mass in gas reactions and mixtures. Key relationships covered are that pressure and volume are inversely related at constant temperature (Boyle's law), volume and temperature are directly related at constant pressure (Charles' law), and volume and moles are directly related at constant temperature and pressure (Avogadro's law).
ACEP Magazine edition 4th launched on 05.06.2024Rahul
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A SYSTEMATIC RISK ASSESSMENT APPROACH FOR SECURING THE SMART IRRIGATION SYSTEMSIJNSA Journal
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Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
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2. BKC3413: Chapter 7 FKKSA, KUKTEM
2
Content
• Type of Evaporation equipment and
Methods
• Overall Heat Transfer Coefficient in
Evaporators
• Calculation Methods for Single Effect
Evaporators
• Calculation Methods for Multiple Effects
Evaporators
• Condenser for Evaporator
• Evaporation using Vapor Recompression
3. BKC3413: Chapter 7 FKKSA, KUKTEM
3
Evaporation
• Heat is added to a solution to vaporize the solvent,
which is usually water.
• Case of heat transfer to a boiling liquid.
• Vapor from a boiling liquid solution is removed and a
more concentrated solution remains.
• Refers to the removal of water from an aqueous
solution.
• Example: concentration of aqueous solutions of
sugar. In these cases the crystal is the desired
product and the evaporated water is discarded.
4. BKC3413: Chapter 7 FKKSA, KUKTEM
4
Processing Factors
Concentration in
the liquid
solubility
Temperature sensitivity
of materials
Foaming or frothing
Pressure and temperature
Scale deposition
Materials of construction
5. BKC3413: Chapter 7 FKKSA, KUKTEM
5
Processing Factors
• Concentration
dilute feed, viscosity , heat transfer coefficient, h
concentrated solution/products, , and h .
• Solubility
concentration , solubility , crystal formed.
solubility with temperature .
• Temperature.
heat sensitive material degrade at higher temperature &
prolonged heating.
6. BKC3413: Chapter 7 FKKSA, KUKTEM
6
• Foaming/frothing.
caustic solutions, food solutions, fatty acid solutions
form foam/froth during boiling.
entrainment loss as foam accompany vapor.
• Pressure and Temperature
pressure , boiling point .
concentration , boiling point.
heat-sensitive material operate under vacuum.
• Material of construction
minimize corrosion.
7. BKC3413: Chapter 7 FKKSA, KUKTEM
7
Effect of Processing Variables on Evaporator Operation.
• TF
TF < Tbp, some of latent heat of steam will be used to heat
up the cold feed, only the rest of the latent heat of steam
will be used to vaporize the feed.
Is the feed is under pressure & TF > Tbp, additional
vaporization obtained by flashing of feed.
• P1
desirable T [Q = UA(TS – T1)],
A & cost .
T1 depends on P1 will T1.
8. BKC3413: Chapter 7 FKKSA, KUKTEM
8
• PS
PS will TS but high-pressure is costly.
optimum TS by overall economic balances.
• BPR
The concentration of the solution are high enough so
that the cP and Tbp are quite different from water.
BPR can be predict from Duhring chart for each
solution such as NaOH and sugar solution.
• Enthalpy–concentration of solution.
for large heat of solution of the aqueous solution.
to get values for hF and hL.
11. BKC3413: Chapter 7 FKKSA, KUKTEM
11
feed, F
TF , xF , hF.
steam, S
TS , HS
concentrated liquid, L
T1 , xL , hL
condensate, S
TS , hS
vapor,V to condenser
T1 , yV , HV
P1
T1
heat-exchanger
tubes
Simplified Diagram of single-effect evaporator
12. BKC3413: Chapter 7 FKKSA, KUKTEM
12
• Single-effect evaporators;
• the feed (usually dilute) enters at TF and saturated
steam at TS enters the heat-exchange section.
• condensed leaves as condensate or drips.
• the solution in the evaporator is assumed to be
completely mixed and have the same composition at
T1.
• the pressure is P1, which is the vapor pressure of the
solution at T1.
• wasteful of energy since the latent heat of the vapor
leaving is not used but is discarded.
• are often used when the required capacity of operation
is relatively small, but it will wasteful of steam cost.
13. BKC3413: Chapter 7 FKKSA, KUKTEM
13
Calculation Methods for Single-effect Evaporator.
• Objectives: to calculate
- vapor, V and liquid, L flowrates.
- heat transfer area, A
- overall heat-transfer coefficient, U.
- Fraction of solid content, xL.
• To calculate V & L and xL,
- solve simultaneously total material balance &
solute/solid balance.
F = L + V total material balance
F (xF) = L (xL) solute/solid balance
14. BKC3413: Chapter 7 FKKSA, KUKTEM
14
• To calculate A or U,
- no boiling point rise and negligible heat of
solution:
calculate hF, hL, Hv and .
where, = (HS – Hs)
h = cP(T – Tref)
where, Tref = T1 = (as datum)
cPF = heat capacity (dilute as water)
HV = latent heat at T1
solve for S:
F hF + S = L hL + V HV
solve for A and U:
q = S = U A T = UA (TS – T1)
15. BKC3413: Chapter 7 FKKSA, KUKTEM
15
• To get BPR and the heat of solution:
- calculate T1 = Tsat + BPR
- get hF and hL from Figure 8.4-3.
- get S & HV from steam tables for superheated
vapor or
HV = Hsat + 1.884 (BPR)
- solve for S:
F hF + S = L hL + V HV
- solve for A and U:
q = S = U A T = UA (TS – T1)
16. BKC3413: Chapter 7 FKKSA, KUKTEM
16
Example 8.4-1: Heat-Transfer Area in Single-Effect
Evaporator.
A continuous single-effect evaporator concentrates 9072
kg/h of a 1.0 wt % salt solution entering at 311.0 K (37.8
ºC) to a final concentration of 1.5 wt %. The vapor space
of the evaporator is at 101.325 kPa (1.0 atm abs) and
the steam supplied is saturated at 143.3 kPa. The
overall coefficient U = 1704 W/m2 .K. calculate the
amounts of vapor and liquid product and the heat-
transfer area required. Assumed that, since it its dilute,
the solution has the same boiling point as water.
17. BKC3413: Chapter 7 FKKSA, KUKTEM
17
U = 1704 W/m2
T1 A = ?
P1 = 101.325 kPa
F = 9072 kg/h
TF = 311 K
xF = 0.01
hF.
S , TS , HS
PS = 143.3 kPa
L = ?
T1 , hL
xL = 0.015
S, TS , hS
V = ?
T1 , yV , HV
Figure 8.4-1: Flow Diagram for Example 8.4-1
18. BKC3413: Chapter 7 FKKSA, KUKTEM
18
Solution;
Refer to Fig. 8.4-1 for flow diagram for this solution.
For the total balance,
F = L + V
9072 = L + V
For the balance on the solute alone,
F xF = L xL
9072 (0.01) = L (0.015)
L = 6048 kg/h of liquid
Substituting into total balance and solving,
V = 3024 kg/h of vapor
19. BKC3413: Chapter 7 FKKSA, KUKTEM
19
Since we assumed the solution is dilute as water;
cpF = 4.14 kJ/kg. K (Table A.2-5)
From steam table, (A.2-9)
At P1 = 101.325 kPa, T1 = 373.2 K (100 ºC).
HV = 2257 kJ/kg.
At PS = 143.3 kPa, TS = 383.2 K (110 ºC).
= 2230 kJ/kg.
The enthalpy of the feed can be calculated from,
hF = cpF (TF – T1)
hF = 4.14 (311.0 – 372.2)
= -257.508 kJ/kg.
20. BKC3413: Chapter 7 FKKSA, KUKTEM
20
Substituting into heat balance equation;
F hF + S = L hL + V HV
with hL = 0, since it is at datum of 373.2 K.
9072 (-257.508) + S (2230) = 6048 (0) + 3024 (2257)
S = 4108 kg steam /h
The heat q transferred through the heating surface
area, A is
q = S ()
q = 4108 (2230) (1000 / 3600) = 2 544 000 W
Solving for capacity single-effect evaporator equation;
q = U A T = U A (TS – T1)
2 544 000 = 1704 A (383.2 – 373.2)
Solving, A = 149.3 m2.
21. BKC3413: Chapter 7 FKKSA, KUKTEM
21
Example 8.4-3: Evaporation of an NaOH Solution.
An evaporator is used to concentrate 4536 kg/h of a
20 % solution of NaOH in water entering at 60 ºC to a
product of 50 % solid. The pressure of the saturated
steam used is 172.4 kPa and the pressure in the
vapor space of the evaporator is 11.7 kPa. The
overall heat-transfer coefficient is 1560 W/m2.K.
calculate the steam used, the steam economy in kg
vaporized/kg steam used, and the heating surface
area in m2.
23. BKC3413: Chapter 7 FKKSA, KUKTEM
23
Solution,
Refer to Fig. 8.4-4, for flow diagram for this solution.
For the total balance,
F = 4536 = L + V
For the balance on the solute alone,
F xF = L xL
4536 (0.2) = L (0.5)
L = 1814 kg/h of liquid
Substituting into total balance and solving,
V = 2722 kg/h of vapor
24. BKC3413: Chapter 7 FKKSA, KUKTEM
24
To determine T1 = Tsat + BPR of the 50 % concentrate
product, first we obtain Tsat of pure water from steam
table. At 11.7 kPa, Tsat = 48.9 ºC.
From Duhring chart (Fig. 8.4-2), for a Tsat = 48.9 ºC and
50 % NaOH , the boiling point of the solution is T1 =
89.5 ºC. hence,
BPR = T1 - Tsat = 89.5-48.9 = 40.6 ºC
From the enthalpy-concentration chart (Fig.8.4-3), for
TF = 60 ºC and xF = 0.2 get hF = 214
kJ/kg.
T1 = 89.5 ºC and xL = 0.5 get hL = 505 kJ/kg.
25. BKC3413: Chapter 7 FKKSA, KUKTEM
25
For saturated steam at 172.4 kPa, from steam table, we get
TS = 115.6 ºC and = 2214 kJ/kg.
To get HV for superheated vapor, first we obtain the enthalpy
at Tsat = 48.9 ºC and P1 = 11.7 kPa, get Hsat = 2590 kJ/kg.
Then using heat capacity of 1.884 kJ/kg.K for superheated
steam. So HV = Hsat + cP BPR
= 2590 + 1.884 (40.6) = 2667 kJ/kg.
Substituting into heat balance equation and solving for S,
F hF + S = L hL + V HV
4535 (214) + S (2214) = 1814 (505) + 2722 (2667)
S = 3255 kg steam /h.
26. BKC3413: Chapter 7 FKKSA, KUKTEM
26
The heat q transferred through the heating surface area, A is
q = S ()
q = 3255 (2214) (1000 / 3600) = 2 002 000 W
Solving for capacity single-effect evaporator equation;
q = U A T = U A (TS – T1)
2 002 000 = 1560 A (115.6 – 89.5)
Solving, A = 49.2 m2.
Steam economy = 2722/3255
= 0.836
27. BKC3413: Chapter 7 FKKSA, KUKTEM
27
EVAPORATION
steam, TS
feed, TF
concentrate
from first
effect.
vapor T1
(1)
T1
(2)
T2
(3)
T3
concentrate
from second
effect.
concentrated
product
condensate
vapor T2 vapor T3
to vacuum
condenser
Simplified diagram of forward-feed triple-effect evaporator
28. BKC3413: Chapter 7 FKKSA, KUKTEM
28
EVAPORATION
• Forward-feed multiple/triple-effect evaporators;
- the fresh feed is added to the first effect and flows to
the next in the same direction as the vapor flow.
- operated when the feed hot or when the final
concentrated product might be damaged at
high temperature.
- at steady-state operation, the flowrates and the rate
of evaporation in each effect are constant.
- the latent heat from first effect can be recovered and
reuse. The steam economy , and reduce steam
cost.
- the Tbp from effect to effect, cause P1 .
29. BKC3413: Chapter 7 FKKSA, KUKTEM
29
EVAPORATION
Calculation Methods for Multiple-effect Evaporators.
• Objective to calculate;
- temperature drops and the heat capacity of
evaporator.
- the area of heating surface and amount of vapor
leaving the last effect.
• Assumption made in operation;
- no boiling point rise.
- no heat of solution.
- neglecting the sensible heat necessary to heat
the feed to the boiling point.
30. BKC3413: Chapter 7 FKKSA, KUKTEM
30
EVAPORATION
• Heat balances for multiple/triple-effect evaporator.
- the amount of heat transferred in the first effect is
approximately same with amount of heat in the
second effect,
q = U1 A1 T1 = U2 A2 T2 = U3 A3 T3
- usually in commercial practice the areas in all
effects are equal,
q/A = U1 T1 = U2 T2 = U3 T3
- to calculate the temperature drops in evaporator,
T = T1 + T2 + T3 = TS – T3
31. BKC3413: Chapter 7 FKKSA, KUKTEM
31
- hence we know that T are approximately
inversely proportional to the values of U,
- similar eq. can be written for T2 & T3
- if we assumed that the value of U is the
same in each effect, the capacity equation,
q = U A (T1 + T2 + T3 ) = UA T
3
2
1
1
1
1
1
1
1
U
U
U
U
T
T
32. BKC3413: Chapter 7 FKKSA, KUKTEM
32
EVAPORATION
Simplified diagram of backward-feed triple-effect evaporator
steam, TS
feed, TF
vapor T1
(1)
T1
(2)
T2
(3)
T3
concentrated
product
condensate
vapor T2 vapor T3
to vacuum
condenser
33. BKC3413: Chapter 7 FKKSA, KUKTEM
33
EVAPORATION
• Backward-feed multiple/triple-effect evaporators;
- fresh feed enters the last and coldest effect and
continues on until the concentrated product
leaves the first effect.
- advantageous when the fresh feed is cold or
when concentrated product is highly viscous.
- working a liquid pump since the flow is from low
to high pressure.
- the high temperature in the first effect reduce the
viscosity and give reasonable heat-transfer
coefficient.
34. BKC3413: Chapter 7 FKKSA, KUKTEM
34
EVAPORATION
Step-by-step Calculation Method for Triple-effect Evaporator (Forward Feed)
For the given x3 and P3 and BPR3
From an overall material balance, determine VT = V1 + V2 + V3
(1st trial – assumption)
Calculate the amount of concentrated solutions & their concentrations in each effect using material balances.
Find BPR & T in each effect & T.
If the feed is very cold, the portions may be modified appropriately, calculate the boiling point in each effect.
Calculate the amount vaporized and concentrated liquid in each effect through energy & material balances.
If the amounts differ significantly from the assumed values in step 2, step 2, and 4 must be repeated with the
amounts just calculated.
Using heat transfer equations for each effect, calculate the surface required for each effect
If the surfaces calculated are not equal, revise the TS . Repeat step 4 onward until the areas are distributed satisfactorily.
35. BKC3413: Chapter 7 FKKSA, KUKTEM
35
EVAPORATION
Ex. 8.5-1 : Evaporation of Sugar Solution in a Triple-Effect
Evaporator.
A triple-effect forward-feed evaporator is being used to
evaporate a sugar solution containing 10 wt% solids to a
concentrated solution of 50 %. The boiling-point rise of the
solutions (independent of pressure) can be estimated from (BPR
ºC = 1.78x + 6.22 x2 ), where x is wt fraction of sugar in solution.
Saturated steam at 205.5 kPa and 121.1ºC saturation
temperature is being used. The pressure in the vapor space of
the third effect is 13.4 kPa. The feed rate is 22 680 kg/h at 26.7
ºC. the heat capacity of the liquid solutions is cP = 4.19 – 2.35x
kJ/kg.K. The heat of solution is considered to be negligible. The
coefficients of heat transfer have been estimated as U1 = 3123,
U2 = 1987, and U3 = 1136 W/m2.K. If each effect has the same
surface area, calculate the area, the steam rate used, and the
steam economy.
37. BKC3413: Chapter 7 FKKSA, KUKTEM
37
Solution,
The process flow diagram is given in Fig. 8.5-1..
Step 1,
From steam table, at P3 = 13.4 kPa, get Tsat = 51.67 ºC.
Using the BPR equation for third effect with xL = 0.5,
BPR3 = 1.78 (0.5) + 6.22 (0.52) =2.45 ºC.
T3 = 51.67 + 2.45 = 54.12 ºC. (BPR = T – Ts)
Step 2,
Making an overall and a solids balance.
F = 22 680 = L3 + (V1 + V2 + V3)
FxF = 22 680 (0.1) = L3 (0.5) + (V1 + V2 + V3) (0)
L3 = 4536 kg/h
Total vaporized = (V1 + V2 + V3) = 18 144 kg/h
38. BKC3413: Chapter 7 FKKSA, KUKTEM
38
Assuming equal amount vaporized in each effect,
V1 = V2 = V3 = 18 144 / 3 = 6048 kg/h
Making a total material balance on effects 1, 2, and 3,
solving
F = 22 680 = V1 + L1 = 6048 + L1, L1 = 16 632 kg/h.
L1 = 16 632 = V2 + L2 = 6048 + L2, L2 = 10 584 kg/h.
L2 = 10 584 = V3 + L3 = 6048 + L3, L3 = 4536 kg/h.
Making a solids balance on each effect, and solving for
x,
22 680 (0.1) = L1 x1 = 16 632 (x1), x1 = 0.136
16 632 (0.136) = L2 x2 = 10 584 (x2), x2 = 0.214
10 584 (0.214) = L3 x3 = 4536 (x3), x3 = 0.5 (check)
39. BKC3413: Chapter 7 FKKSA, KUKTEM
39
Step 3, The BPR in each effect is calculated as follows:
BPR1 = 1.78x1 + 6.22x1
2 = 1.78(0.136) + 6.22(0.136)2
= 0.36ºC.
BPR2 = 1.78(0.214) + 6.22(0.214)2 =0.65ºC.
BPR3 = 1.78(0.5) + 6.22(0.5)2 =2.45ºC. then,
T available = TS1 – T3 (sat) – (BPR1 + BPR2 + BPR3 )
= 121.1 – 51.67 – (0.36+0.65+2.45) = 65.97ºC.
Using Eq.(8.5-6) for T1 , T2 , and T3
T1 = 12.40 ºC T2 = 19.50 ºC T3 = 34.07 ºC
3
2
1
1
1
1
1
1
1
U
U
U
U
T
T
)
1136
1
(
)
1987
1
(
)
3123
1
(
)
3123
1
(
97
.
65
40. BKC3413: Chapter 7 FKKSA, KUKTEM
40
However, since a cold feed enters effect number 1, this
effect requires more heat. Increasing T1 and lowering T2
and T3 proportionately as a first estimate, so
T1 = 15.56ºC T2 = 18.34 ºC T3 = 32.07 ºC
To calculate the actual boiling point of the solution in each
effect,
T1 = TS1 - T1 = 121.1 – 15.56 = 105.54 ºC.
T2 = T1 - BPR1 - T2 = 105.54 – 0.36 – 18.34 = 86.84 ºC.
TS2 = T1 –BPR1 = 105.54 – 0.36 = 105.18 ºC.
T3 = T2 - BPR2 - T3= 86.84 – 0.65 – 32.07 = 54.12 ºC.
TS3 = T2 –BPR2 = 86.84 – 0.65 = 86.19 ºC.
The above data T1, T2 and T3 are getting from iteration-s
41. BKC3413: Chapter 7 FKKSA, KUKTEM
41
The temperatures in the three effects are as follows:
Effect 1 Effect 2 Effect 3 Condenser
TS1 = 121.1ºC TS2 = 105.18 TS3 = 86.19 TS4 = 51.67
T1 = 105.54 T2 = 86.84 T3 = 54.12
Step 4,
The heat capacity of the liquid in each effect is calculated
from the equation cP = 4.19 – 2.35x.
F: cPF = 4.19 – 2.35 (0.1) = 3.955 kJ/kg.K
L1: cP1 = 4.19 – 2.35 (0.136) = 3.869 kJ/kg.K
L2: cP2 = 4.19 – 2.35 (0.214) = 3.684 kJ/kg.K
L3: cP3 = 4.19 – 2.35 (0.5) = 3.015 kJ/kg.K
42. BKC3413: Chapter 7 FKKSA, KUKTEM
42
The values of the enthalpy H of the various vapor streams
relative to water at 0 ºC as a datum are obtained from the
steam table as follows:
Effect 1:
H1 = HS2 + 1.884 BPR1 = 2684 + 1.884(0.36) 2685 kJ/kg.
S1 = HS1 – hS1 = 2708 – 508 = 2200 kJ/kg.
Effect 2:
H2 = HS3 + 1.884 BPR2= 2654 + 1.884(0.65) = 2655 kJ/kg.
S2 = H1 – hS2 = 2685 – 441 = 2244 kJ/kg.
Effect 3:
H3 = HS4 + 1.884 BPR3 = 2595 + 1.884(2.45) = 2600 kJ/kg.
S3 = H2 – hS3 = 2655– 361 = 2294 kJ/kg.
43. BKC3413: Chapter 7 FKKSA, KUKTEM
43
Write the heat balance on each effect. Use 0ºC as a datum.
FcPF (TF –0) + SS1 = L1cP1 (T1 –0) + V1H1 ,, ………(1)
22680(3.955)(26.7-0)+2200S = 3.869L1(105.54-0)+(22680-L1)2685
L1cP1 (T1 –0) + V1S2 = L2cP2 (T2 –0) + V2H2 ………(2)
3.869L1(105.54-0)+(22680-L1)2244=3.684L2(86.84-0)+(L1-L2)2655
L2cP2 (T2 –0) + V2S3 = L3cP3 (T3 –0) + V3H3 ………(3)
3.68L2(86.84-0)+(L1-L2)2294=4536(3.015)(54.1-0)+(L2-4536)2600
Solving (2) and (3) simultaneously for L1&L2 and
substituting into(1)
L1 = 17078 kg/h L2 = 11068 kg/h L3 = 4536 kg/h
S = 8936kg/h V1 = 5602kg/h V2 = 6010kg/h
V3 = 6532kg/h
44. BKC3413: Chapter 7 FKKSA, KUKTEM
44
EVAPORATION
Step 5, Solving for the values of q in each effect and area,
W
x
x
S
q S
6
1
1 10
460
.
5
1000
2200
3600
8936
W
x
x
V
q S
6
2
1
2 10
492
.
3
1000
2244
3600
5602
W
x
x
V
q S
6
3
2
3 10
830
.
3
1000
2294
3600
6010
2
6
1
1
1
1 4
.
112
65
.
15
3123
10
460
.
5
m
x
T
U
q
A
2
6
2
2
2
2 8
.
95
34
.
18
1987
10
492
.
3
m
x
T
U
q
A
2
6
3
3
3
3 1
.
105
07
.
32
1136
10
830
.
3
m
x
T
U
q
A
2
3
2
1
4
.
104
3
)
(
m
A
A
A
Am
45. BKC3413: Chapter 7 FKKSA, KUKTEM
45
EVAPORATION
Am = 104.4 m2, the areas differ from the average value by
less than 10 % and a second trial is really not necessary.
However, a second trial will be made starting with step 6
to indicate the calculation methods used.
Step 6,
Making a new solids balance by using the new L1 =
17078, L2 = 11068, and L3 = 4536, and solving for x,
22 680 (0.1) = L1 x1 = 17 078 (x1), x1 = 0.133
17 078 (0.130) = L2 x2 = 11 068 (x2), x2 = 0.205
11 068 (0.205) = L3 x3 = 4536 (x3), x3 = 0.5 (check)
46. BKC3413: Chapter 7 FKKSA, KUKTEM
46
EVAPORATION
Step 7. The new BPR in each effect is then,
BPR1 = 1.78(0.133) + 6.22(0.13)2 =0.35ºC.
BPR2 = 1.78(0.205) + 6.22(0.205)2 =0.63ºC.
BPR3 = 1.78(0.5) + 6.22(0.5)2 =2.45ºC. then,
T available = 121.1 – 51.67 – (0.35+0.63+2.45) = 66.0
ºC.
The new T are obtained using Eq.(8.5-11),
C
A
A
T
T
m
77
.
16
4
.
104
4
.
112
56
.
15
1
1
'
1
C
A
A
T
T
m
86
.
16
4
.
104
8
.
95
34
.
18
2
2
'
2
C
A
A
T
T
m
34
.
32
4
.
104
1
.
105
07
.
32
3
3
'
3
C
T
97
.
65
34
.
32
86
.
16
77
.
16
47. BKC3413: Chapter 7 FKKSA, KUKTEM
47
These T’ values are readjusted so that T 1`= 16.77,
T 2`= 16.87, T 3` = 32.36, and T = 66.0 ºC. To
calculate the actual boiling point of the solution in each
effect,
(1) T1 = TS1 + T 1` = 121.1 – 16.77 = 104.33ºC
(2) T2 = T1 – BPR1 - T 2` = 104.33 – 0.35 – 16.87 = 87.11 ºC
TS2 = T1 – BPR1 = 104.33 – 0.35 = 103.98ºC
(3) T3 = T2 – BPR2 - T 3` = 87.11 – 0.63 – 32.36 = 54.12 ºC
TS3 = T2 – BPR2 = 87.11 – 0.63 = 86.48 ºC.
Step 8;
Following step 4 to get cP = 4.19 – 2.35x,
F: cPF = 4.19 – 2.35 (0.1) = 3.955 kJ/kg.K
L1: cP1 = 4.19 – 2.35 (0.133) = 3.877 kJ/kg.K
L2: cP2 = 4.19 – 2.35 (0.205) = 3.705 kJ/kg.K
L3: cP3 = 4.19 – 2.35 (0.5) = 3.015 kJ/kg.K
49. BKC3413: Chapter 7 FKKSA, KUKTEM
49
EVAPORATION
Solving for q and A in each effect,
W
x
x
S
q S
6
1
1 10
476
.
5
1000
2200
3600
8960
W
x
x
V
q S
6
2
1
2 10
539
.
3
1000
2243
3600
5675
W
x
x
V
q S
6
3
2
3 10
855
.
3
1000
2293
3600
6053
2
6
'
1
1
1
1 6
.
104
77
.
16
3123
10
476
.
5
m
x
T
U
q
A
2
6
'
2
2
2
2 6
.
105
87
.
16
1987
10
539
.
3
m
x
T
U
q
A
2
6
'
3
3
3
3 9
.
104
36
.
32
1136
10
855
.
3
m
x
T
U
q
A
50. BKC3413: Chapter 7 FKKSA, KUKTEM
50
EVAPORATION
The average area Am = 105.0 m2 to use in
each effect.
steam economy = ???? [Q/Vapor Flowrate]
025
.
2
8960
6416
6053
5675
3
2
1
S
V
V
V