This document provides an overview of Kern's method for designing shell-and-tube heat exchangers. It begins with objectives and an introduction to Kern's method. It then outlines the design procedure algorithm and provides an example application. The example involves designing an exchanger to sub-cool methanol condensate using brackish water as the coolant. The document walks through each step of the Kern's method design process for this example, including calculating properties, determining duties, selecting tube/shell parameters, and estimating heat transfer coefficients.
A condenser is a heat exchanger that transfers vapors into a liquid state by removing latent heat with a coolant like water. This document provides design calculations for an 8 unit shell and tube condenser with 1030 tubes that uses cold water as the coolant to condense steam at a rate of 8060 kg/hr and 4343 kW of heat duty. Key specifications are provided, like a calculated overall heat transfer coefficient of 1100.97 W/m2C and pressure drops of 0.59 psi for the tube side and 0.109 psi for the shell side. References on condenser design are also listed.
Selection and Design of Condensers
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 CHOICE OF COOLANT
5 LAYOUT CONSIDERATIONS
5.1 Distillation Column Condensers
5.2 Other Process Condensers
6 CONTROL
6.1 Distillation Columns
6.2 Water Cooled Condensers
6.3 Refrigerant Condensers
7 GENERAL DESIGN CONSIDERATIONS
7.1 Heat Transfer Resistances
7.2 Pressure Drop
7.3 Handling of Inerts
7.4 Vapor Inlet Design
7.5 Drainage of Condensate
8 SUMMARY OF TYPES AVAILABLE
8.1 Direct Contact Condensers
8.2 Shell and Tube Exchangers
8.3 Air Cooled Heat Exchangers
8.4 Spiral Plate Heat Exchangers
8.5 Internal Condensers
8.6 Plate Heat Exchangers
8.7 Plate-Fin Heat Exchangers
8.8 Other Compact Designs
9 BIBLIOGRAPHY
FIGURES
1 DIRECT CONTACT CONDENSER WITH INDIRECT COOLER FOR RECYCLED CONDENSATE
2 SPRAY CONDENSER
3 TRAY TYPE CONDENSER
4 THREE PASS TUBE SIDE CONDENSER WITH INTERPASS LUTING FOR CONDENSATE DRAINAGE
5 CROSS FLOW CONDENSER WITH SINGLE PASS COOLANT
Packed columns are used for distillation, gas absorption, and liquid-liquid extraction. They have continuous gas-liquid contact through a packed bed, unlike plate columns which have stage-wise contact. Packed columns depend on good liquid and gas distribution, and have lower holdup but higher pressure drop than plate columns. This document provides details on packed column components, design procedures such as selecting packing and determining height, and examples of absorption and stripping processes in packed columns.
The document describes the modified Claus process for sulfur recovery. It discusses the basic Claus reaction and how the modified process improved on it with a free flame oxidation ahead of the catalyst bed and catalytic step revisions, allowing for higher sulfur recovery efficiencies of 90-99.9%. The key steps of the modified Claus process are presented as the combustion step and multiple catalytic steps. Process variations like the straight-through and split-flow configurations are described along with tail gas handling and other sulfur removal processes. Sample calculations are provided to determine the optimum operating parameters for a 80 long ton per day sulfur recovery unit using the modified Claus process.
Equilibrium Effects
- Methane Steam
- Water Gas Shift
Relationship of Kp to Temperature
Relationship of WGS Kp to Temperature
Effect of Temperature on Methane Slip
Approach to Equilibrium
Reaction Path and Equilibrium
Effect of Pressure Increase
Operating Parameters
- Pressure
- Temperature
- Feed Rate
- Steam to Carbon
Effect of Exit Temperature Spread
Useful Tools
Calculating ATM
A reboiler is a heat exchanger that provides heat to the bottom of a distillation column. There are several types of reboilers including kettle reboilers, thermosyphon reboilers, fired reboilers, and forced circulation reboilers. Kettle reboilers are simple devices where steam flows through tubes in a shell to heat liquid in the shell. Thermosyphon reboilers use density differences to circulate liquid without pumps. Fired reboilers use combustion to heat liquid circulating through tubes. Forced circulation reboilers use pumps to circulate liquid through shell and tube heat exchangers.
A condenser is a heat exchanger that transfers vapors into a liquid state by removing latent heat with a coolant like water. This document provides design calculations for an 8 unit shell and tube condenser with 1030 tubes that uses cold water as the coolant to condense steam at a rate of 8060 kg/hr and 4343 kW of heat duty. Key specifications are provided, like a calculated overall heat transfer coefficient of 1100.97 W/m2C and pressure drops of 0.59 psi for the tube side and 0.109 psi for the shell side. References on condenser design are also listed.
Selection and Design of Condensers
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 CHOICE OF COOLANT
5 LAYOUT CONSIDERATIONS
5.1 Distillation Column Condensers
5.2 Other Process Condensers
6 CONTROL
6.1 Distillation Columns
6.2 Water Cooled Condensers
6.3 Refrigerant Condensers
7 GENERAL DESIGN CONSIDERATIONS
7.1 Heat Transfer Resistances
7.2 Pressure Drop
7.3 Handling of Inerts
7.4 Vapor Inlet Design
7.5 Drainage of Condensate
8 SUMMARY OF TYPES AVAILABLE
8.1 Direct Contact Condensers
8.2 Shell and Tube Exchangers
8.3 Air Cooled Heat Exchangers
8.4 Spiral Plate Heat Exchangers
8.5 Internal Condensers
8.6 Plate Heat Exchangers
8.7 Plate-Fin Heat Exchangers
8.8 Other Compact Designs
9 BIBLIOGRAPHY
FIGURES
1 DIRECT CONTACT CONDENSER WITH INDIRECT COOLER FOR RECYCLED CONDENSATE
2 SPRAY CONDENSER
3 TRAY TYPE CONDENSER
4 THREE PASS TUBE SIDE CONDENSER WITH INTERPASS LUTING FOR CONDENSATE DRAINAGE
5 CROSS FLOW CONDENSER WITH SINGLE PASS COOLANT
Packed columns are used for distillation, gas absorption, and liquid-liquid extraction. They have continuous gas-liquid contact through a packed bed, unlike plate columns which have stage-wise contact. Packed columns depend on good liquid and gas distribution, and have lower holdup but higher pressure drop than plate columns. This document provides details on packed column components, design procedures such as selecting packing and determining height, and examples of absorption and stripping processes in packed columns.
The document describes the modified Claus process for sulfur recovery. It discusses the basic Claus reaction and how the modified process improved on it with a free flame oxidation ahead of the catalyst bed and catalytic step revisions, allowing for higher sulfur recovery efficiencies of 90-99.9%. The key steps of the modified Claus process are presented as the combustion step and multiple catalytic steps. Process variations like the straight-through and split-flow configurations are described along with tail gas handling and other sulfur removal processes. Sample calculations are provided to determine the optimum operating parameters for a 80 long ton per day sulfur recovery unit using the modified Claus process.
Equilibrium Effects
- Methane Steam
- Water Gas Shift
Relationship of Kp to Temperature
Relationship of WGS Kp to Temperature
Effect of Temperature on Methane Slip
Approach to Equilibrium
Reaction Path and Equilibrium
Effect of Pressure Increase
Operating Parameters
- Pressure
- Temperature
- Feed Rate
- Steam to Carbon
Effect of Exit Temperature Spread
Useful Tools
Calculating ATM
A reboiler is a heat exchanger that provides heat to the bottom of a distillation column. There are several types of reboilers including kettle reboilers, thermosyphon reboilers, fired reboilers, and forced circulation reboilers. Kettle reboilers are simple devices where steam flows through tubes in a shell to heat liquid in the shell. Thermosyphon reboilers use density differences to circulate liquid without pumps. Fired reboilers use combustion to heat liquid circulating through tubes. Forced circulation reboilers use pumps to circulate liquid through shell and tube heat exchangers.
This document compares different methods for designing a shell and tube heat exchanger, including a manual design, HTRI software, and Aspen Exchanger Design and Rating (EDR). It first provides background on heat exchangers and describes the constraints that must be met in a heat exchanger design, including thermal and hydraulic evaluations. It then presents an example design case and shows the initial geometry selection. Finally, it discusses using HTRI and Aspen EDR software for simulation, rating, and designing shell and tube heat exchangers, noting both programs iterate to find a design meeting constraints.
Heat exchangers transfer thermal energy between two or more fluids at different temperatures. They are classified based on their transfer process, geometry, heat transfer mechanism, and flow arrangement. Shell-and-tube heat exchangers consist of a set of tubes in a shell container and are the most important type, used across many industries. Their design involves calculating the heat transfer rate, selecting appropriate materials and geometry, and ensuring optimal fluid velocities and pressure drops within design limits.
Why have a Secondary Reformer ?
Need nitrogen to make ammonia
Wish to make primary as small as possible
Wish to minimise methane slip since methane is an inert in the ammonia synthesis loop
Other methods of achieving this
Braun Purifier process
Can address all these with an air blown secondary
Ammonia production from natural gas, haldor topsoe processGaurav Soni
The document provides information about the various sections of an ammonia plant, including the desulfurization, reforming, shift, CO2 removal, methanation, and ammonia synthesis sections. It details the processes that occur in each section, including catalysts used and operating parameters. The goal is to produce 99.73% pure ammonia from natural gas feedstock using a high-pressure synthesis process.
1) Conversion and reactor sizing for different reactor types such as batch, CSTR, PFR and reactors in series are discussed. Key equations for calculating conversion and sizing reactors given reaction rate data are presented.
2) Examples are provided to calculate the volume of a CSTR and PFR needed to achieve 80% conversion of a reactant based on rate data, and to compare the required volumes between reactor types.
3) For an isothermal reaction, a CSTR typically requires a larger volume than a PFR to achieve the same conversion due to operating at the lowest reaction rate throughout the reactor.
Visbreaking and delayed coking are processes used in oil refineries. Visbreaking uses heat to crack large hydrocarbon molecules and reduce viscosity, producing gas, naphtha, and distillates. It occurs in either coil or soaker units. Delayed coking thermally cracks residual oil in parallel furnaces and drums, producing coker gas oil and petroleum coke while maximizing distillates and minimizing coke yield. Problems include fouling, coke formation, and asphaltene precipitation, which can be addressed using high pressure heat exchangers.
This document provides an introduction to heat exchangers, including their classification, types, components, and design considerations. Heat exchangers transfer thermal energy between fluids or between fluids and solids. Common types include shell and tube, plate and frame, air cooled, and spiral designs. Key components of shell and tube heat exchangers are the shell, tubes, tubesheet, baffles, and nozzles. Tube layout, pitch, pass arrangements, and baffle design impact heat transfer and pressure drop. Bypass and leakage streams must be minimized for optimal performance.
Selection of Heat Exchanger Types
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 BACKGROUND
5 FACTORS INFLUENCING SELECTION
5.1 Type of Duty
5.2 Temperatures and Pressures
5.3 Materials of Construction 5.4 Fouling
5.5 Safety and Reliability
5.6 Repairs
5.7 Design Methods
5.8 Dimensions and Weight
5.9 Cost
5.10 GBHE Experience
6 TYPES OF EXCHANGER
6.1 Shell and Tube Exchangers
6.2 Cylindrical Graphite Block Heat Exchangers
6.3 Cubic Graphite Block Heat Exchangers
6.4 Air Cooled Heat Exchangers
6.5 Gasketed Plate and Frame
6.6 Spiral Plate
6.7 Tube in Duct
6.8 Plate-fin
6.9 Printed Circuit Heat Exchanger (PCHE)
6.10 Scraped Surface/Wiped Film Exchangers
6.11 Welded or Brazed Plate
6.12 Double Pipe
6.13 Electric Heaters
6.14 Fired Process Heaters
TABLE
(1) ADVANTAGES AND DISADVANTAGES OF DIFFERENT SHELL AND TUBE DESIGNS
FIGURES
1 ESTIMATED MAIN PLANT ITEM COSTS
2 ESTIMATED INSTALLED COSTS
3 TEMA HEAT EXCHANGER NOMENCLATURE
4 F ‘CORRECTION FACTORS' : TEMA E SHELL WITH EVEN NUMBER OF PASSE
5 SHELL AND TUBE HEAT EXCHANGER HEAD TYPES
6 GENERAL ARRANGEMENT OF A CYLINDRICAL GRAPHITE BLOCK HEAT EXCHANGER
7 EXPLODED VIEW OF A CUBIC GRAPHITE BLOCK
HEAT EXCHANGER
8 TYPICAL AIR COOLED HEAT EXCHANGER
9 GENERAL VIEW OF ONE END OF A 3-STREAM
PLATE-FIN HEAT EXCHANGER
10 TYPICAL PCHE PLATE
11 VICARB ‘COMPABLOC' EXCHANGER
12 ‘BROWN FINTUBE' MULTITUBE HEAT EXCHANGER
13 FIRED HEATER : SCHEMATICS AND NOMENCLATURE
This document discusses the process design of shell and tube heat exchangers. It begins by classifying heat exchangers and describing different types of shell and tube heat exchangers such as fixed tube sheet, removable tube bundle, floating head, and U-tube designs. The document then discusses various thermal design considerations for shell and tube heat exchangers, including selections for the shell, tube materials and dimensions, tube layout and count, baffles, and fouling considerations. It provides process design procedures and an example problem for shell and tube heat exchanger design.
The document discusses various petroleum refining processes including catalytic isomerization, UOP Butamer and Penex isomerization processes, catalytic polymerization, UOP catalytic polymerization process, alternative UOP tubular reactor design, and the IFP Dimersol process. It provides details on the chemistry and operating principles of each process, including feedstocks, reactions, yields, equipment used and product properties. The overall purpose is to describe several key technologies used in refineries to convert petroleum fractions into higher octane products like gasoline.
This document provides calculations for the rate of distillation and size of a vapor column for distilling triethyl amine. It calculates the total heat transfer area and rate of vaporization as 1410.218 kg/hr. The diameter of the vapor column is calculated as approximately 4 inches and the height is approximately 10 feet. Various equations and data are presented to illustrate the step-by-step calculations and determine the necessary parameters for designing distillation equipment.
This document summarizes different processes for removing carbon dioxide from ammonia plant streams. It discusses why CO2 removal is important, and describes common processes like MEA and MDEA absorption. The Benfield process uses hot potassium carbonate solution promoted by diethanolamine to physically absorb CO2. Issues with the Benfield process include foaming, corrosion, and vanadation problems. Retrofitting with a new amine promoter called LRS 10 can improve CO2 removal efficiency and reduce energy costs for the Benfield process.
COURSE LINK:
https://www.chemicalengineeringguy.com/courses/gas-absorption-stripping/
Introduction:
Gas Absorption is one of the very first Mass Transfer Unit Operations studied in early process engineering. It is very important in several Separation Processes, as it is used extensively in the Chemical industry.
Understanding the concept behind Gas-Gas and Gas-Liquid mass transfer interaction will allow you to understand and model Absorbers, Strippers, Scrubbers, Washers, Bubblers, etc…
We will cover:
- REVIEW: Of Mass Transfer Basics required
- GAS-LIQUID interaction in the molecular level, the two-film theory
- ABSORPTION Theory
- Application of Absorption in the Industry
- Counter-current & Co-current Operation
- Several equipment to carry Gas-Liquid Operations
- Bubble, Spray, Packed and Tray Column equipments
- Solvent Selection
- Design & Operation of Packed Towers
- Pressure drop due to packings
- Solvent Selection
- Design & Operation of Tray Columns
- Single Component Absorption
- Single Component Stripping/Desorption
- Diluted and Concentrated Absorption
- Basics: Multicomponent Absorption
- Software Simulation for Absorption/Stripping Operations (ASPEN PLUS/HYSYS)
----
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CONTACT ME
Chemical.Engineering.Guy@Gmail.com
www.ChemicalEngineeringGuy.com
http://facebook.com/Chemical.Engineering.Guy
You speak spanish? Visit my spanish channel -www.youtube.com/ChemEngIQA
This document discusses various thermodynamic diagrams used for boiler calculations, including:
- Temperature-heat (T-Q) diagrams which show the heat transfer characteristics of heat exchangers and boiler components.
- Temperature-entropy (T-s) diagrams which represent the phases of steam/water and can display steam processes.
- Pressure-enthalpy (p-h) diagrams which make it easy to visualize the heat load shares on different boiler surfaces.
- Enthalpy-entropy (Mollier) diagrams which allow determining steam properties from two known parameters like pressure and temperature.
These diagrams provide useful visualization tools for designing and analyzing boiler performance and steam processes.
An overview of distillation column design concepts and major design considerations. Explains distillation column design concepts, what you would provide to a professional distillation column designer, and what you can expect back from a distillation system design firm. To speak with an engineer about your distillation column project, call EPIC at 314-207-4250.
applications of the principles of heat transfer to design of heat exchangersKathiresan Nadar
This file contain a very good description for the processes design of heat ex changer. the file courtesy is Prof. Anand Patwardhan ICT Mumbai (Deemed University)
This document compares different methods for designing a shell and tube heat exchanger, including a manual design, HTRI software, and Aspen Exchanger Design and Rating (EDR). It first provides background on heat exchangers and describes the constraints that must be met in a heat exchanger design, including thermal and hydraulic evaluations. It then presents an example design case and shows the initial geometry selection. Finally, it discusses using HTRI and Aspen EDR software for simulation, rating, and designing shell and tube heat exchangers, noting both programs iterate to find a design meeting constraints.
Heat exchangers transfer thermal energy between two or more fluids at different temperatures. They are classified based on their transfer process, geometry, heat transfer mechanism, and flow arrangement. Shell-and-tube heat exchangers consist of a set of tubes in a shell container and are the most important type, used across many industries. Their design involves calculating the heat transfer rate, selecting appropriate materials and geometry, and ensuring optimal fluid velocities and pressure drops within design limits.
Why have a Secondary Reformer ?
Need nitrogen to make ammonia
Wish to make primary as small as possible
Wish to minimise methane slip since methane is an inert in the ammonia synthesis loop
Other methods of achieving this
Braun Purifier process
Can address all these with an air blown secondary
Ammonia production from natural gas, haldor topsoe processGaurav Soni
The document provides information about the various sections of an ammonia plant, including the desulfurization, reforming, shift, CO2 removal, methanation, and ammonia synthesis sections. It details the processes that occur in each section, including catalysts used and operating parameters. The goal is to produce 99.73% pure ammonia from natural gas feedstock using a high-pressure synthesis process.
1) Conversion and reactor sizing for different reactor types such as batch, CSTR, PFR and reactors in series are discussed. Key equations for calculating conversion and sizing reactors given reaction rate data are presented.
2) Examples are provided to calculate the volume of a CSTR and PFR needed to achieve 80% conversion of a reactant based on rate data, and to compare the required volumes between reactor types.
3) For an isothermal reaction, a CSTR typically requires a larger volume than a PFR to achieve the same conversion due to operating at the lowest reaction rate throughout the reactor.
Visbreaking and delayed coking are processes used in oil refineries. Visbreaking uses heat to crack large hydrocarbon molecules and reduce viscosity, producing gas, naphtha, and distillates. It occurs in either coil or soaker units. Delayed coking thermally cracks residual oil in parallel furnaces and drums, producing coker gas oil and petroleum coke while maximizing distillates and minimizing coke yield. Problems include fouling, coke formation, and asphaltene precipitation, which can be addressed using high pressure heat exchangers.
This document provides an introduction to heat exchangers, including their classification, types, components, and design considerations. Heat exchangers transfer thermal energy between fluids or between fluids and solids. Common types include shell and tube, plate and frame, air cooled, and spiral designs. Key components of shell and tube heat exchangers are the shell, tubes, tubesheet, baffles, and nozzles. Tube layout, pitch, pass arrangements, and baffle design impact heat transfer and pressure drop. Bypass and leakage streams must be minimized for optimal performance.
Selection of Heat Exchanger Types
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 BACKGROUND
5 FACTORS INFLUENCING SELECTION
5.1 Type of Duty
5.2 Temperatures and Pressures
5.3 Materials of Construction 5.4 Fouling
5.5 Safety and Reliability
5.6 Repairs
5.7 Design Methods
5.8 Dimensions and Weight
5.9 Cost
5.10 GBHE Experience
6 TYPES OF EXCHANGER
6.1 Shell and Tube Exchangers
6.2 Cylindrical Graphite Block Heat Exchangers
6.3 Cubic Graphite Block Heat Exchangers
6.4 Air Cooled Heat Exchangers
6.5 Gasketed Plate and Frame
6.6 Spiral Plate
6.7 Tube in Duct
6.8 Plate-fin
6.9 Printed Circuit Heat Exchanger (PCHE)
6.10 Scraped Surface/Wiped Film Exchangers
6.11 Welded or Brazed Plate
6.12 Double Pipe
6.13 Electric Heaters
6.14 Fired Process Heaters
TABLE
(1) ADVANTAGES AND DISADVANTAGES OF DIFFERENT SHELL AND TUBE DESIGNS
FIGURES
1 ESTIMATED MAIN PLANT ITEM COSTS
2 ESTIMATED INSTALLED COSTS
3 TEMA HEAT EXCHANGER NOMENCLATURE
4 F ‘CORRECTION FACTORS' : TEMA E SHELL WITH EVEN NUMBER OF PASSE
5 SHELL AND TUBE HEAT EXCHANGER HEAD TYPES
6 GENERAL ARRANGEMENT OF A CYLINDRICAL GRAPHITE BLOCK HEAT EXCHANGER
7 EXPLODED VIEW OF A CUBIC GRAPHITE BLOCK
HEAT EXCHANGER
8 TYPICAL AIR COOLED HEAT EXCHANGER
9 GENERAL VIEW OF ONE END OF A 3-STREAM
PLATE-FIN HEAT EXCHANGER
10 TYPICAL PCHE PLATE
11 VICARB ‘COMPABLOC' EXCHANGER
12 ‘BROWN FINTUBE' MULTITUBE HEAT EXCHANGER
13 FIRED HEATER : SCHEMATICS AND NOMENCLATURE
This document discusses the process design of shell and tube heat exchangers. It begins by classifying heat exchangers and describing different types of shell and tube heat exchangers such as fixed tube sheet, removable tube bundle, floating head, and U-tube designs. The document then discusses various thermal design considerations for shell and tube heat exchangers, including selections for the shell, tube materials and dimensions, tube layout and count, baffles, and fouling considerations. It provides process design procedures and an example problem for shell and tube heat exchanger design.
The document discusses various petroleum refining processes including catalytic isomerization, UOP Butamer and Penex isomerization processes, catalytic polymerization, UOP catalytic polymerization process, alternative UOP tubular reactor design, and the IFP Dimersol process. It provides details on the chemistry and operating principles of each process, including feedstocks, reactions, yields, equipment used and product properties. The overall purpose is to describe several key technologies used in refineries to convert petroleum fractions into higher octane products like gasoline.
This document provides calculations for the rate of distillation and size of a vapor column for distilling triethyl amine. It calculates the total heat transfer area and rate of vaporization as 1410.218 kg/hr. The diameter of the vapor column is calculated as approximately 4 inches and the height is approximately 10 feet. Various equations and data are presented to illustrate the step-by-step calculations and determine the necessary parameters for designing distillation equipment.
This document summarizes different processes for removing carbon dioxide from ammonia plant streams. It discusses why CO2 removal is important, and describes common processes like MEA and MDEA absorption. The Benfield process uses hot potassium carbonate solution promoted by diethanolamine to physically absorb CO2. Issues with the Benfield process include foaming, corrosion, and vanadation problems. Retrofitting with a new amine promoter called LRS 10 can improve CO2 removal efficiency and reduce energy costs for the Benfield process.
COURSE LINK:
https://www.chemicalengineeringguy.com/courses/gas-absorption-stripping/
Introduction:
Gas Absorption is one of the very first Mass Transfer Unit Operations studied in early process engineering. It is very important in several Separation Processes, as it is used extensively in the Chemical industry.
Understanding the concept behind Gas-Gas and Gas-Liquid mass transfer interaction will allow you to understand and model Absorbers, Strippers, Scrubbers, Washers, Bubblers, etc…
We will cover:
- REVIEW: Of Mass Transfer Basics required
- GAS-LIQUID interaction in the molecular level, the two-film theory
- ABSORPTION Theory
- Application of Absorption in the Industry
- Counter-current & Co-current Operation
- Several equipment to carry Gas-Liquid Operations
- Bubble, Spray, Packed and Tray Column equipments
- Solvent Selection
- Design & Operation of Packed Towers
- Pressure drop due to packings
- Solvent Selection
- Design & Operation of Tray Columns
- Single Component Absorption
- Single Component Stripping/Desorption
- Diluted and Concentrated Absorption
- Basics: Multicomponent Absorption
- Software Simulation for Absorption/Stripping Operations (ASPEN PLUS/HYSYS)
----
Please show the love! LIKE, SHARE and SUBSCRIBE!
More likes, sharings, suscribers: MORE VIDEOS!
-----
CONTACT ME
Chemical.Engineering.Guy@Gmail.com
www.ChemicalEngineeringGuy.com
http://facebook.com/Chemical.Engineering.Guy
You speak spanish? Visit my spanish channel -www.youtube.com/ChemEngIQA
This document discusses various thermodynamic diagrams used for boiler calculations, including:
- Temperature-heat (T-Q) diagrams which show the heat transfer characteristics of heat exchangers and boiler components.
- Temperature-entropy (T-s) diagrams which represent the phases of steam/water and can display steam processes.
- Pressure-enthalpy (p-h) diagrams which make it easy to visualize the heat load shares on different boiler surfaces.
- Enthalpy-entropy (Mollier) diagrams which allow determining steam properties from two known parameters like pressure and temperature.
These diagrams provide useful visualization tools for designing and analyzing boiler performance and steam processes.
An overview of distillation column design concepts and major design considerations. Explains distillation column design concepts, what you would provide to a professional distillation column designer, and what you can expect back from a distillation system design firm. To speak with an engineer about your distillation column project, call EPIC at 314-207-4250.
applications of the principles of heat transfer to design of heat exchangersKathiresan Nadar
This file contain a very good description for the processes design of heat ex changer. the file courtesy is Prof. Anand Patwardhan ICT Mumbai (Deemed University)
iaetsd Heat transfer enhancement of shell and tube heat exchanger using conic...Iaetsd Iaetsd
This document discusses heat transfer enhancement in a shell and tube heat exchanger using a conical tape insert. It provides heat transfer and friction factor data from experiments using the heat exchanger fitted with a helical tape insert. Hot air was passed through the inner tube while cold water flowed in the annulus. The helical insert increased heat transfer rate by up to 165% compared to the plain tube, with some increase in pressure drop. Equations and calculations are provided for determining heat transfer coefficients, pressure drops, and other parameters on both the shell and tube sides of the heat exchanger. Graphs of results are also presented.
Thermal rating of Shell & Tube Heat ExchangerVikram Sharma
This presentation file was created with the objective to provide a refresher course on the thermal rating of Shell and Tube heat exchanger for single-phase heat transfer
Analysis comparing performance of a conventional shell and tube heat exchange...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
The document summarizes an experiment on a small shell and tube heat exchanger. Two technical objectives were tested: 1) varying the tube side flow rate while keeping the shell side constant, and 2) varying the shell side flow rate while keeping the tube side constant. Key results showed that increasing the flow rate on either side decreased temperatures and increased the heat transfer coefficient. The heat loss to the environment initially increased with flow before decreasing at the highest flow rate tested.
This document discusses heat exchangers, which allow the transfer of heat between two fluids without direct contact. It describes several types of heat exchangers including double pipe heat exchangers, which involve two concentric pipes, and shell and tube heat exchangers, which involve tubes inside a cylindrical shell. Shell and tube heat exchangers are widely used and involve tubes, tube sheets, baffles, and multiple passes to increase heat transfer. The document also discusses applications and advantages and disadvantages of different heat exchanger designs.
This document describes a design project report on adipic acid produced by students Shivika Agrawal, Nikhil Nevatia, and Satish Pillai. It includes chapters on the introduction to adipic acid, market analysis of global and Indian demand and production capacity, a comparison of production processes and selection of a process, material and energy balances, equipment design, and a cost estimation. The main points are that adipic acid is mainly used to produce nylon 6,6 and has a global demand of 3.3 million metric tons growing at 3-5% annually, with China as the largest importer and Europe the largest market. India currently imports its requirements of adipic acid.
The document outlines the key aspects of the scientific method, including defining a problem as a question, researching existing information on the topic, developing a hypothesis as a predicted outcome, designing an experiment with independent, dependent, and control variables to collect data and observations, and analyzing the results to draw conclusions that answer the original question and prove or disprove the hypothesis.
The document discusses the lecture method of instruction. It defines the lecture method as an oral presentation of factual information where the teacher is very active and does all the talking while students listen passively. It notes that the lack of student involvement limits its effectiveness. The document provides information on when and how to use the lecture method, highlighting that it is best for introducing new topics to students with little prior knowledge as long as the teacher is well prepared and incorporates questions, discussions and visual aids to engage students. Both advantages like facilitating large classes and disadvantages like passive student participation are outlined.
The direct instruction/lecture method is aimed at helping students acquire procedural knowledge or skills needed to perform tasks. It involves the teacher demonstrating skills, providing guided practice, checking for understanding, and assessing learning. Key characteristics include the teacher directing the lesson in a step-by-step fashion to ensure all procedures are learned correctly. Objectives focus on observable behaviors that can be accurately measured. Guidelines for effective use include providing ample practice time, involving students in planning, and dividing complex skills into simpler steps.
The document discusses the project method as a teaching approach. It notes that projects allow students to develop independence and responsibility while practicing social skills. The history of the project method is explored, from its origins in European architectural schools in the 15th century to its adoption in American progressive education. Key characteristics of good projects are identified as having clear objectives and appropriate scope while challenging students. The document argues that the project method aligns well with modern learning principles by being useful, beneficial, and stimulating further learning through practice and application.
This document discusses piping, fittings, and valves used in fluid dynamics. It begins by defining common piping terminology and describing common piping materials like steel, copper, plastic, and ceramics. It then discusses factors for pipe selection like fluid type and operating conditions. Key aspects of piping design covered include material roughness, pipe sizing methods using schedules and BWG, and considerations for pipe expansion and supports. Common pipe fittings are also defined, including flanges, elbows, reducers, and flow measurement devices. Finally, the document outlines the purpose and types of valves used to control fluid flow, such as globe, ball, gate, and safety valves.
This presentation describes the considerations involved in selecting the shell and tube exchanger according to TEMA Designations. Also, it helps to identify whether fluid should be sent tube side or shell side
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2. Designing Shell-and-Tube Heat Exchangers Using Softwares
Lecture 1: Kern’s Method
By:
Majid Hayati
University of Kashan, Kashan, I.R. IRAN
2014
3. 3
Schedule – Kern’s Method
Kern’s method
Introduction to Kern’s method
Algorithm of design procedure for shell-and-tube heat exchangers
Design procedure steps along with an example
4. 4
Objectives
This lecture on designing shell-and-tube HEs serves as an
introduction lecture to the subject, and covers:
Introduction to “Kern’s method” definition along with its
advantages and disadvantages
Developing an algorithm for the design of shell-and-tube
exchangers
Finally, following up the procedure set out in the algorithm in an
example
5. 5
Introduction to Kern’s method
Kern’s was based on experimental work on commercial
exchanger
Advantages:
Giving reasonably satisfactory prediction of the heat-transfer
coefficient for standard design
Simple to apply
Accurate enough for preliminary design calculations
Accurate enough for designs when uncertainty in other design
parameter is such that the use of more elaborate method is not
justified
Disadvantage:
The prediction of pressure drop is less satisfactory, as pressure
drop is more affected by leakage and bypassing than heat transfer
The method does not take account of the bypass and leakage
streams
6. 6
Design procedure for shell-and-tube heat exchangers
(Kern’s method)
Start
Calculate tube number
Calculate shell diameter
Assume value of overall
coefficient Uo,ass
Collect physical properties and
HE specifications
End
Estimate tube- and shell-side
heat transfer coefficient
Estimate tube- and shell-side
pressure drop
Question: Are pressure drops
within specification?
Estimate tube- and shell-side heat
transfer coefficient-go to step 3
Accept all design parameters
Compare to estimated overall
heat transfer coefficient
Determine overall heat transfer
coefficient
Start from step 3
Step 1
Step 2
Step 3
Step 4
Step 6
Step 7
Step 8
Define duty
Make energy balance if needed
Calculate unspecified flow rates
Calculate ΔTLMTD and ΔTM
Fig. 1: Algorithm of design procedure
Determine fouling factors
Step 5
Yes
No
NoYes
Start
Collect physical properties and
HE specifications
Step 1
Collect physical properties and
HE specifications
Step 1
Step 2
Define duty
Make energy balance if needed
Step 2
Define duty
Make energy balance if needed
Calculate unspecified flow rates
Calculate ΔTLMTD and ΔTM
Assume value of overall
coefficient Uo,ass
Step 3
Assume value of overall
coefficient Uo,ass
Step 3
Calculate tube number
Calculate shell diameter
Step 4
Calculate tube number
Calculate shell diameter
Step 4
Determine fouling factors
Step 5
Determine fouling factors
Step 5
Estimate tube- and shell-side
heat transfer coefficient
Step 6
Estimate tube- and shell-side
heat transfer coefficient
Step 6
Estimate tube- and shell-side
pressure drop
Step 7
Estimate tube- and shell-side
pressure drop
Step 7
YesYes No
Determine overall heat transfer
coefficient
Step 8
Determine overall heat transfer
coefficient
Step 8
No
Yes
Accept all design parameters
7. 7
Kern’s Method Design Example
Design an exchanger to sub-cool condensate from a
methanol condenser from 95 °C to 40 °C
Flow-rate of methanol 100,000 kg/h
Brackish water (seawater) will be used as the coolant, with a
temperature rise from 25° to 40 °C
8. 8
Collect physical properties and HE specifications:
Physical properties
Solution: Step 1
WaterMethanolPhysical properties at
fluid mean temperature
4.22.84Cp (Kj/Kg °C)
0.80.34μ (mNs/m2)
0.590.19kf (W/m °C)
995750ρ (Kg/m3)
Table 1
HE specifications:
Coolant (brackish water) is corrosive, so assign to tube-side.
Use one shell pass and two tube passes.
At shell side, fluid (methanol) is relatively clean. So, use 1.25 triangular pitch
(pitch: distance between tube centers).
9. 9
Tube Arrangements
The tubes in an exchanger are usually arranged in an
equilateral triangular, square, or rotated square pattern (Fig.
2)
Fig. 2: Tube patterns
10. 10
Tube Pattern Applications
The triangular and rotated square patterns give higher heat-
transfer rates, but at the expense of a higher pressure drop
than the square pattern.
A square, or rotated square arrangement, is used for
heavily fouling fluids, where it is necessary to mechanically
clean the outside of the tubes.
The recommended tube pitch is 1.25 times the tube outside
diameter; and this will normally be used unless process
requirements dictate otherwise.
11. 11
Define duty, Make energy balance if needed
To start step 2, the duty (heat transfer rate) of methanol (the hot stream or
water, the cold stream) needed to be calculated.
Step 2
kW4340=40)(952.84×
3600
100000
=)T(TCm=Q=loadHeat 21phh
•
--
Fig. 3: Streams definitions.
12. 12
Step 2 (Cont’d)
The cold and the hot stream heat loads are equal. So, cooling water flow rate
is calculated as follow:
kg/s68.9=
25)(404.2
4340
=
)t(tC
Q
=m=flowwaterCooling _
12cP
.
c _
The well-known “logarithmic mean” temperature difference (LMTD or lm) is
calculated by:
C31
25)(40
40)(95
ln
25)(4040)(95
tT
tT
ln
)t(T)t(T
ΔT
12
21
1221
LMTD
13. 13
Mean Temperature Difference
The usual practice in the design of shell and tube
exchangers is to estimate the “true temperature difference”
from the logarithmic mean temperature by applying a
correction factor to allow for the departure from true
counter-current flow:
LMTDtm ΔTFΔT
Where:
ΔTm = true temperature difference,
Ft = the temperature correction factor.
14. 14
Temperature Correction Factor
The correction factor (Ft) is a function of the shell and tube
fluid temperatures, and the number of tube and shell
passes.
It is normally correlated as a function of two dimensionless
temperature ratios:
11
12
12
21
tT
tt
S
tt
TT
R
15. 15
For a 1 shell : 2 tube pass exchanger, the correction factor
is plotted in Fig. 4.
Step 2
)TEMAre even tube passes (available inFig. 4: Temperature correction factor: one shell pass; two or mo
16. 16
Step 2 (Cont’d)
From Fig. 4, the correction factor (Ft) is 0.85.
21.0
2595
2540
)t(T
)t(t
S
67.3
2540
4095
tt
TT
R
11
12
12
21
C26310.85ΔTFΔT LMTDtm
17. 17
Assume value of overall coefficient Uo,ass
Typical values of the overall heat-transfer coefficient for various
types of heat exchanger are given in Table 1.
Fig. 5 can be used to estimate the overall coefficient for tubular
exchangers (shell and tube).
The film coefficients given in Fig. 5 include an allowance for fouling.
The values given in Table 1 and Fig. 5 can be used for the preliminary
sizing of equipment for process evaluation, and as trial values for
starting a detailed thermal design.
From Table 2 or Fig. 5: U=600 W/m2°C
Step 3
19. 19
Step 3 (Cont’d)
Fig. 5: Overall coefficients (join process side duty to service side and read U from centre scale)
20. 20
Step 4
Calculate tube number, Calculate shell diameter
Provisional area:
So, the total outside surface area of tubes is 278 m2
Choose 20 mm o.d. (outside diameter), 16 mm i.d. (inside diameter),
4.88-m-long tubes ( ), cupro-nickel.
Allowing for tube-sheet thickness, take tube length: L= 4.83 m
Surface area of one tube: A = πDL = 4.83 x 20 x 10-3π = 0.303 m2
2
3
M
m278=
62×600
10×4340
=
TΔU
Q
=A
ft16in.
4
3
918
0.303
278
tubeoneofareasurfaceOutside
area)al(ProvisiontubesofareasurfaceoutsideTotal
tubesofNumbers
21. 21
Step 4 (Cont’d)
An estimate of the bundle diameter Db can be obtained from
equation below which is an empirical equation based on standard
tube layouts. The constants for use in this equation, for triangular
and square patterns, are given in Table 3.
where Db = bundle diameter in mm, do = tube outside diameter in
mm., Nt = number of tubes.
As the shell-side fluid is relatively clean use 1.25 triangular pitch.
So, for this example:
1n
1
1
t
ob )
K
N
(dD
mm826)
0.249
918
(20DdiameterBundle 2.207
1
b
23. 23
Step 4 (Cont’d)
Use a split-ring floating head type for Fig. 6.
From Fig. 6, bundle diametrical clearance is 68 mm.
Shell diameter (Ds):
Ds= Bundle diameter + Clearance = 826 + 68 = 894 mm.
Note 1: nearest standard pipe size are 863.6 or 914.4 mm.
Note 2: Shell size could be read from standard tube count tables
[Kern (1950), Ludwig (2001), Perry et al. (1997), and Saunders (1988)].
25. 25
Estimate tube- and shell-side heat transfer coefficient
Tube-side heat transfer coefficient:
Since we have two tubes pass, we divide the total numbers of tubes
by two to find the numbers of tubes per pass, that is:
Total flow area is equal to numbers of tubes per pass multiply by
tube cross sectional area:
Step 6
459=
2
918
=passperTubes
222
3
avg
mm201=16×
4
π
=D
4
π
=(a)areasectional-crossTube
mkg995=ρC33=
2
25+40
=)(TetemperaturwaterMean ⇒
26
m0.092=)10×(201×459=areaflowTotal
26. 26
Step 6 (Cont’d)
Fig. 7: Equivalent diameter, cross-sectional areas and wetted perimeters.
27. 27
Coefficients for water: a more accurate estimate can be made by
using equations developed specifically for water.
The physical properties are conveniently incorporated into the
correlation. The equation below has been adapted from data given by
Eagle and Ferguson (1930):
where hi = inside coefficient, for water, W/m2 °C,
t = water temperature, °C,
ut = water linear velocity, m/s,
di = tube inside diameter, mm.
Step 6 (Cont’d)
2
mskg749=
0.092
68.9
=
areaflowTotal
flowwaterCooling
=velocitymassWater
sm0.75=
995
749
=
)ρ(densityWater
)(GvelocitymassWater
=)(uvelocitylinearWater t
t
0.2
i
0.8
i
d
u0.02t)+(1.354200
=h
28. 28
The equation can also be calculated using equation below; this is
done to illustrate use of this method.
where hi = inside coefficient, for water, W/m2 °C,
di = tube inside diameter, mm
kf = fluid thermal conductivity, W/m2 °C
jh = heat transfer factor, dimensionless
Re = Reynolds number, dimensionless
Pr = Prandtl number, dimensionless
μ = viscosity of water, N s/m2
μw = viscosity of water at wall temperature, N s/m2
Step 6 (Cont’d)
0.14
w
0.33
h
f
ii
)
μ
μ
(PrRej=
k
dh
CW/m3852=
16
0.7533)×0.02+(1.354200
=
d
u0.02t)+(1.354200
=h 2
0.2
0.8
0.2
i
0.8
i
29. 29
Neglect
Check reasonably the previously calculated value 3812 W/m2°C with
value calculated, 3852 W/m2°C.
Step 6 (Cont’d)
)
μ
μ
(
w
5.7=
0.59
10×0.8×10×4.2
=
k
μC
=Pr
14925=
10×8
10×16×0.75×995
=
μ
ρud
=Re
CmW0.59=1TablefromtyconductivithermalFluid
mmNs0.8=1Tablefrom)μ(waterofViscosity
33
f
p
3
3
i
2
_
_
3
h
3
i
_
10×3.9=j8,Fig.From302=
16
10×4.83
=
d
L
⇒
CmW3812=1×5.7×14925×10×3.9×
10×16
0.59
=)
μ
μ
(PrRej
d
k
=h 20.140.333
3
0.14
w
0.33
h
i
f
i
_
_
31. 31
Shell-side heat transfer coefficient:
Baffle spacing: The baffle spacings used range from 0.2 to 1.0 shell
diameters.
A close baffle spacing will give higher heat transfer coefficients but at the
expense of higher pressure drop.
Area for cross-flow: calculate the area for cross-flow As for the hypothetical
row at the shell equator, given by:
Where pt = tube pitch (distance between the centers of two tubes, Fig. 7).
do = tube outside diameter, m,
Ds = shell inside diameter, m,
lb = baffle spacing, m.
Note: the term is the ratio of the clearance between tubes and
the total distance between tube centers.
Step 6 (Cont’d)
t
bso
_
t
s
p
l)Dd(p
=A
t
o
_
t
p
)d(p
32. 32
Baffle spacing:
Choose baffle spacing = 0.2 Ds=0.2 894 = 178 mm
Tube pitch:
Pt = 1.25 do= 1.25 20 = 25 mm
Cross-flow area:
Step 6 (Cont’d)
26
_
bs
t
o
_
t
s m0.032=10×178×894×
25
20)(25
=lD
p
)d(p
=A
_
33. 33
Shell-side mass velocity Gs and the linear velocity ut:
Where Ws = fluid flow-rate on the shell-side, kg/s,
ρ = shell-side fluid density, kg/m3.
Shell equivalent diameter (hydraulic diameter): calculate the shell-
side equivalent diameter, see Fig. 7. For an equilateral triangular
pitch arrangement:
Where de = equivalent diameter, m.
Step 6 (Cont’d)
ρ
G
=u
A
W
=G
s
s
s
s
s
)d0.917(p
d
1.10
=
2
πd
)
4
d
π
2
1
0.87p×
2
p
(4
=d 2
o
_2
t
oo
2
o_
t
t
e
34. 34
Shell-side mass velocity Gs:
Shell equivalent diameter (hydraulic diameter):
Step 6 (Cont’d)
2
s
s
s
ms
kg
868=
0.032
1
×
3600
100000
=
A
W
=Gvelocity,Mass
mm14.4=)20×0.917(25
20
1.1
=)d0.917(p
d
1.10
=d 2_22
o
_2
t
o
e
35. 35
Choose 25 per cent baffle cut, from Fig. 9
Step 6 (Cont’d)
5.1=
0.19
10×0.34×10×2.84
=
k
μC
=Pr
36762=
10×0.34
10×14.4×868
=
μ
dG
=
μ
dρu
=Re
CmW0.19=1TabletyconductiviThermal
CkgkJ2.84=1TablefromcapacityHeat
)mmNs0.34=1Tablefrom(μmethanolofViscosity
)mkg750=1Tablefrom)ρ(densityMethanol
C68=
2
40+95
=etemperatursideshellMean
33
f
p
3
3
eses
2
3
_
_
-
3
h
_
10×3.3=j
37. 37
For the calculated Reynolds number, the read value of jh from Fig. 9
for 25 per cent baffle cut and the tube arrangement, we can now
calculate the shell-side heat transfer coefficient hs from:
The tube wall temperature can be estimated using the following
method:
Mean temperature difference across all resistance: 68 -33 =35 °C
across methanol film
Mean wall temperature = 68 – 8 = 60 °C
μ = 0.37 mNs/m2
Which shows that the correction for low-viscosity fluid is not significant.
Step 6 (Cont’d)
2740=
5.1×36762×10×3.3×
10×1.44
0.19
=hterm)correctionviscosity(without)
μ
μ
(PrRej=
k
dh
=Nu 313-
3-s
0.14
w
31
h
f
es
→
0.99=)
μ
μ
( 0.14
w
C8=35×
2740
600
=ΔT×
h
U
=
o
38. 38
Pressure drop
Tube side: From Fig. 10, for Re = 14925
jf = 4.3 10-3
Neglecting the viscosity correction term:
low, could consider increasing the number of tube passes.
Shell side
From Fig. 11, for Re = 36762
jf = 4 10-2
Neglect viscosity correction
Step 7 (Cont’d)
m/s1.16=
750
868
=
ρ
G
=velocityLinear s
psi)(1.1kPa7.2=mN7211=
2
0.75×995
2.5)+)
16
10×4.83
(10×4.3×(82=
uρ
2.5]+)
μ
μ
)(
d
L
([8jN=ΔP
2
23
3-
2
tm-
wi
fpt
41. 41
could be reduced by increasing the baffle pitch. Doubling the pitch halves
the shell side velocity, which reduces the pressure drop by a factor of
approximately (1/2)2
This will reduce the shell-side heat-transfer coefficient by a factor of
(1/2)0.8(ho Re0.8 us
0.8)
ho = 2740 (1/2)0.8 = 1573 W/m2°C
This gives an overall coefficient of 615 W/m2°C – still above assumed value of
600 W/m2°C
Step 7 (Cont’d)
acceptable(10psi),kPa68=
4
272
=ΔPs
high,toopsi)(39kPa272=
mN272019=
2
1.16×750
)
178
10×4.83
()
14.4
894
(10×4×8=
2
uρ
)
L
L
)(
d
D
(8j=ΔP
2
23
2-
2
t
se
s
fs
∝ ∝
42. 42
Take the thermal conductivity of cupro-nickel alloys from Table 1, 50
W/m°C, the fouling coefficients from Table 3; methanol (light organic)
5000 Wm-2°C-1, brackish water (sea water), take as highest value, 3000
Wm-2°C-1
Well above assumed value of 600 Wm-2°C
Step 8 (Cont’d)
CmW738=U
3812
1
×
16
20
+
3000
1
×
16
20
+
50×2
16
20
ln10×20
+
5000
1
+
2740
1
=
U
1
h
1
×
d
d
+
h
1
×
d
d
+
K2
d
d
lnd
+
h
1
+
h
1
=
U
1
2
o
3-
o
ii
o
idi
o
w
i
o
o
odoo
43. 43
References
1. EAGLE, A. and FERGUSON, R. M. (1930) Proc. Roy. Soc.
A. 127, 540. On the coefficient of heat transfer fromthe
internal surfaces of tube walls.
2. KERN, D. Q. (1950) Process Heat Transfer (McGraw-Hill).
3. LUDWIG, E. E. (2001) Applied Process Design for
Chemical and Petroleum Plants, Vol. 3, 3rd edn (Gulf).
4. PERRY, R. H., GREEN, D.W. and MALONEY, J. O. (1997)
Perry’s Chemical Engineers Handbook, 7th edn (McGraw-
Hill).
5. SAUNDERS, E. A. D. (1988) Heat Exchangers
(Longmans).