cet33at lab manual

FACULTY OF ENGINEERING AND THE BUILT ENVIRONMENT

DEPARTMENT OF CHEMICAL AND METELLURGICAL ENGINEERING

NAME OF COURSE:

CHEMICAL ENGINEERING TECHNOLOGY( IIIA)

NQF LEVEL

NQF CREDITS QUALIFICATION & SAQA ID COURSE CODE

Diploma In CHEMICAL ENGINEERINGSAQA ID No.:

(CET33AT)

COMPILED BY (Molelekoa Mosesane)

(2015)

STUDENT LABORATORY GUIDE

©COPYRIGHT : Tshwane University of Technology

Private Bag X680

PRETORIA

0001

All rights reserved. Apart from any reasonable quotations for the purposes of research criticism or review as permitted under the Copyright Act, no part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy and recording, without permission in writing from the publisher.

Printed and distributed by :

FACULTY OF ENGINEERING AND BUILT ENVIRONMENT

Tshwane University of Technology

ORGANISATIONAL COMPONENT CONTENTS:

1.......................................................................................................................................Welcome......................................................................................................................................................6

2..................................................................................................................LABORATORY Staff......................................................................................................................................................7

2.1 Contact Details.............................................................................................................8

2.2 Staff availability...........................................................................................................8

3. ...............................................................Requirements, resources and recommended material.......................................................................................................................................................9

3.1 Requirements for the course.......................................................................................10

4. ..........................................................................................................................Code of conduct....................................................................................................................................................12

Safety..........................................................................................................................................12

B. Laboratory Format and Procedures.................................................................................12

4.1 Attendance..................................................................................................................15

4.2 LABORATORY, HEALTH & SAFETY RULES AND REGULATIONS..............16

4.3 Responsibilities of students........................................................................................16

5. Assessment.............................................................................................................................17

5.1 Assessment methods and criteria...............................................................................17

5.2 Assessment rules.........................................................................................................17

5.3 Marking system..........................................................................................................17

5.4 predicate/Year mark...................................................................................................18

5.5 Moderation..................................................................................................................19

5.6 Promotion requirements.............................................................................................20

6. ......................................................................................laboratory course content and schedule....................................................................................................................................................20

6.1 schedule of laboratory sessions and assignments.......................................................20

6.2 Learning outcomes and assessment criteria................................................................21

6.3 Generic outcomes and critical cross-field outcomes..................................................22

7. Glossary of terms....................................................................................................................22

7.1.Assessment Records.............................................................................................................22

7.2 Example of a practical report......................................................................................23

Guidelines for the Preparation of Written Reports..............................................................23

A. Apparatus............................................................................................................................24

B. Procedure.............................................................................................................................24

Unit study for the study of load losses 25

Test bench pumps 31

Heat exchanger pilot plant......................................................................................................39

Concentric heat exchanger......................................................................................................49

9. ExampleS of mark sheets used during various assessments.......................................56

SECTION A ORGANISATIONAL COMPONENT

1. WELCOME

Welcome to laboratory session of Chemical Engineering Technology IIIA. This part of the

course provides an introduction and represents advanced knowledge in unity operation and is

offered via experimental work, problem-based work or project-based work over 8 weeks. The

course is structured in such a way as to master theoretical concepts and principles and various

practical skills to provide a sound foundation for the study of Load Losses, Test bench pumps

and Heat transfer to complement the major courses in the qualification and pave the way for

more advanced learning in B-Tech in Chemical engineering. We trust you will enjoy the

course, and find it interesting and informative.

2. LABORATORY STAFF

2.1 CONTACT DETAILS

NAME CAMPUS ROOM NO TEL NO AND E-MAIL CONSULTATION TIME

ACADEMIC FUNCTION

Mr M.S Ranyaoa

Pretoria B3 – R 707 (012) 382 3514

[email protected]

Lecturer

Mr M. Mosesane

Pretoria B2 – R127 9012) 382 4655 9h00 – 16h00 Technologist

2.2 STAFF AVAILABILITY

If, after attending class and making every effort from your side to master content, you still have problems with understanding key concepts or principles or their application, lecturers are available for consultation.

To consult your lecturer, make an appointment by calling his office or see/ call the secretary at (012) 382 3550/3514 for an appointment.

To consult your technologist, make an appointment by calling his office at 012 382 4655 or call the secretary at (012) 382 3514.

mailto:[email protected]

3. REQUIREMENTS, RESOURCES AND RECOMMENDED MATERIAL.

3.1 REQUIREMENTS FOR THE COURSE

3.1.1 PRESCRIBED RESOURCES

The following tables indicate what literature and other resources are essential for successful completion of this course. You are strongly advised to acquire all the prescribed resources.

PRESCRIBED RESOURCES

CATEGORY DESCRIPTION WHERE TO FIND COST LEVY

CALCULATOR Scientific Bookstore

COMPUTER Soshanguve, Arcadia and Pretoria campuses

HARDWARE Laboratory Journal/Record Book ( Not a page or exam pad )

Bookstore

SOFTWARE

EQUIPMENT

Building 2 lab. 127

Load Losses Study Unit, Test Bench Pilot Plant and Heat Exchanger Pilot Plant with Three Exchangers.

COMPONENTS

3.1.2 RECOMMENDED RESOURCES

The following recommend resources will enhance your understanding and knowledge in this course, and you are encouraged to use the following additional resources.

RECOMMENDED RESOURCES

CATEGORY AUTHOR NAME PUBLISHER ISBN NO

BOOKS Library books

MANUALS Laboratory manual

Online

GUIDES Study guides Online

RECOMMENDED ELECTRONIC MATERIAL & WEBSITES

VIDEO

CD

DVD

WEBSITES myTUTor

tut4life.tut.ac.za

4. CODE OF CONDUCT

Please take note of the following regulations. These regulations are in addition to the standard rules and regulations as determined by the TUT. Please familiarise yourself with the TUT rules and regulations as set out in the student diaries received on registration.

Safety

Laboratory safety is the top priority and this requires all people in the lab to be observing safe practices at all times!

• Safety glasses must always be worn by everyone in the laboratory.

• Make sure you understand how the experimental apparatus works and what all

of the adjustments done before you attempt to operate it.

• Be sure you have asked, and received an answer, from the Technician

about any possible hazards related to your experiment before attempting to operate it.

• Care must be used in the handling of chemicals to avoid spills and to avoid contact with the skin.

B. Laboratory Format and Procedures

1. Organization of Student Groups and Laboratory Projects

Students will organize into groups of five persons. Each group is to perform three projects during the semester. (A roster of the groups and a schedule of projects will be supplied separately.)

A group leader, who is in charge of directing the work for the lab, should be selected by, and from among, the members of the group. (This responsibility should rotate among the members.) All group members must be prepared for the laboratory and contribute equally to the laboratory work and preparation of the reports. However, the group leader is in charge of assigning and coordinating tasks for the laboratory period and maintaining the group notebook. He or she is ultimately responsible for making sure that everything is done to ensure a successful experiment.

2. Laboratory Session 1

At the beginning of the first session for a given experiment, a paragraph describing the experimental plan and procedure should be submitted to the Technician who is in charge at that time. A discussion between the Technician and the students will take place to ensure that students have an accurate plan of action.

3. Laboratory Session 2

The Technical report should be submitted to the Technician in charge of the experiment. A summary discussion of the report with the instructor will be conducted in the laboratory.

4. Session 3

The laboratory will be open to gather additional data if needed. The lecturer will be available for consultations during the first hour of the laboratory period. During this session

examination of the experimental apparatus for the next assigned project should be performed by each group.

5. Final Technical Report .

The final Technical report is due at the beginning of the next scheduled laboratory period following Session 3. There are no exceptions to this deadline. The reports are to be submitted to one of the department secretaries in the Chemical Engineering office or to the Technician. During the week following the day on which the final report was submitted, the group should schedule a meeting with the lecturer for the discussion of the written report. Each member of the group should be prepared to defend and/or discuss any part of the final report.

6. Laboratory Notebook

Part of the purpose of the chemical engineering laboratories is to learn good laboratory and research practices. An important aspect of this is safety. Another important aspect is record-keeping and documentation. In industry you will find that all experiments have to be carefully recorded in an official laboratory notebook and signed by the investigator on a daily basis. To help foster these professional practices, each group is required to keep a laboratory notebook documenting the group's work. In the notebook should be kept a neat, labeled and dated record of all work associated with the experiment, including a copy of the precis, all raw data, the settings on the experimental controls, any problems encountered in the experiment and what was done to fix them and why, all calculations, a copy of your progress report, etc. The laboratory notebooks will be handed in at the end of the semester and will contribute to the laboratory participation portion of your grade.

7. Student Responsibilities in the Laboratory

Condition of Working Area. Students are responsible for the condition of their working area at the end of each laboratory period.

All power to the equipment and instruments should be turned off, and steam and cooling water flows should be shut off.

Glassware used should be cleaned and dried. Any equipment or instrumentation malfunctions should be

reported promptly to the Technician or assistants.

Checkout before Leaving Laboratory. The students must have their notebooks initialed by a Technician prior to leaving at the end of the laboratory period. At that time the Technician will check the working area and take information about any equipment or instrumentation problems.

8. Grading/Marking

Report grading is done by the lecturers who are in charge of a given experiment. This grade will be based on the written report, the oral defense and other pertinent factors (e.g., if you are

totally unprepared to do an experiment, you will be docked.) Grades for this course will be determined by the grades on the three experiments as well as your laboratory participation. The laboratory participation portion of your grade in will include how well you followed laboratory safety guidelines (did you wear safety glasses at all times in the lab? did you follow the special safety precautions required for each experiment?), attendance, tardiness, participation, professionalism, how effective a group leader you were, and the quality of your laboratory notebook. Both laboratory instructors and teaching assistants will contribute towards this portion of your grade.

4.1 ATTENDANCE

Regular attendance of the chemical engineering technology (IIIA) lectures is of primary importance. It is the learner’s responsibility to sign the register each week. A minimum attendance of 75% is mandatory for all courses including practical In a 30 week year, 8 classes that have not been attended and for which you have not furnished a valid doctor’s letter or other proof of extenuating circumstances, amounts to 25% absenteeism. This level of absenteeism will lead to exclusion from the final moderation at the end of the year, which means that you will fail the course and will have to repeat it the following year.

4.2 LABORATORY, HEALTH & SAFETY RULES AND REGULATIONS

4.2.1. LABORATORY RULES

BASIC RULES

Always wear a laboratory coat in the laboratory.

Do not wear open shoes in the laboratory.

Do not eat or drink in the laboratory.

No horse-playing in the laboratory.

Always ask the technician if you are not sure of anything.

4.3 RESPONSIBILITIES OF STUDENTS

It is your responsibility to make a success of learning in this course. To this end you are encouraged to attend practical class, write practical report and hand in your assignments/projects on the set due dates.

SECTION B LEARNING COMPONENT

5. ASSESSMENT

5.1 ASSESSMENT METHODS AND CRITERIA

Assessment of this laboratory course will include experimental work, problem-based work, Project-based works and assignments, report writing. The purpose of assessment is to determine whether you have achieved the learning outcomes. The various assessment methods therefore will focus on criteria that will enable the lecturer(s) to determine whether you have achieved the learning outcomes and mastered the required skills. The assessment criteria relevant to each learning outcome are detailed in section 2.2.

5.2 ASSESSMENT RULES

The general rules of TUT regarding assessment apply. You are advised to familiarise yourself with these rules, as they are applied stringently.

5.3 MARKING SYSTEM

SUBJECT MAX MARK ACTUAL MARK

1. TITLE PAGE 1

2. ABSTRACT 6

3. INTRODUCTION 2

4. THEORETICAL BACKGROUND 3

5. PROCEDURE 2

6. RESULTS 6

7. DISCUSSION OF RESULTS 10

8. CONCLUSION AND RECOMMENDATIONS

4

9. LITERATURE CITED 1

10. NOMENCLATURE 1

11. ORGANIZATION AND NEATNESS

2

Appendix

A1 Raw Data 2

A2 Data analysis and Sample Calculations

10

TOTAL 50

5.4 PREDICATE/YEAR MARK

The practical mark will contribute 50% to the year mark

Predicate marks are put on the faculty notice boards. If you have queries about your mark, you must immediately consult your course lecturer , before predicate day. Once the predicate mark is entered on TUT’s mainframe computer, the mark cannot be changed.

1.5 MODERATION

The lecturer of the subject will be responsible to moderate all practical report.

1.6 PROMOTION REQUIREMENTS

The leaner has to obtain the minimum of 50% in the practical report in order to pass.

6. LABORATORY COURSE CONTENT AND SCHEDULE

This course comprises of an experimental component, problem-based component and a project-based component. Your mastery of the required skills is assessed at regular intervals. More importantly, the application of theory is assessed through problem-based- or project-based assignments or projects.

The following outline provides an overview of the content to be covered in this course and the ways in which your progress will be assessed.

6.1 SCHEDULE OF LABORATORY SESSIONS AND ASSIGNMENTS

DURATION THEME

EXPERIMENTAL/

PROBLEM-BASED/

PROJECT-BASED

COMPLETION DATE*

Week 1-4Load Losses

(Learning Outcome 1)

Obtain the relationship between the straight pipe head loss and the volume flow rate by plotting log hL against log Q.

Plot friction factor data versus Reynold’s number for the straight pipe. Also obtain relationship between F and Ren ; by plotting log f against log Re. Comment on your

PRESSURE

DROP IN

PIPING

SYSTEMS

results by comparing with the literature given equation.

Obtain the value for K for the gate valve when it is fully opened and compare with literature.

Discuss head losses in 90° Mitre and standard elbow bend.

Obtain the value for K for globe valve when it is fully opened and compare with literature.

Determine the discharge coefficient used in the characterization of the flow meters (orifice and venturi)

Compare the measured and the literature discharge coefficients.

Week 5-8TEST BENCH

(Learning Outcomes 2 )

It is expected that the students will be able to

Calculate system head requirements.

Determine head, pump efficiency, and pump horsepower from a typical pump curve.

Compute NPSH required by the pump.

Describe how to modify system to operate on the appropriate pump curve.

TEST

BENCH

Week 9- 12 HEAT TRANSFER PILOT PLANT

(Learning Outcomes 3 )

It is expected that students will be able to:

Carry out an energy balance for the

tube side and the shell side

Compute the experimental overall

heat transfer coefficient for the heat

HEAT

TRANSFER

exchanger (for each run)

Plot on log-log scale the computed

experimental heat transfer

coefficient versus the shell side

Reynold’s number.

Calculate the theoretical overall heat transfer coefficient and compare with the experimental one.

*Please note that test dates may be moved on short notice where circumstances require

such change. Also, take particular note of the rules regarding tests and assignments in

section B, 2.6

6.2 LEARNING OUTCOMES AND ASSESSMENT CRITERIA

The following tables clearly indicate what you have to achieve (the learning outcomes) and how you will be assessed (assessment criteria) to determine whether you have achieved the required knowledge and competences:

LEARNING OUTCOME 1:

Load losses

Assessment criteria Assessment method

Familiarize yourself with the pilot plant and identify flow meter, manometer the pump and its type and all different types of

Oral test

pipes used on the pilot plant.

Calculate the discharge coefficient, load and frictional losses.

Be able to correlate the results from the experiment and the theoretical calculations.

Task performance

Correct raw data collection

Observation by lab personnel

Written report

LEARNING OUTCOME 2:

Test bench pumps


Understanding of pumps, pump curves, pump efficiency, pump relations i.e affinity laws and energy balance concept.

Task performance

Oral test



Written report

LEARNING OUTCOME 3:

Heat exchanger


Knowledge and understanding of energy balance equation

Ability to understand the types of flow and the conditions they are applicable to.

Task performance

Oral test



Written report

6.3 GENERIC OUTCOMES AND CRITICAL CROSS-FIELD OUTCOMES

Compliance with Critical cross-field Outcomes

Compliance with Generic Engineering and

Built Environment Outcomes

Knowledge and understanding of energy balance equation

Communication and written skills

Solving engineering problem

Problem solving

Application of scientific and engineering knowledge

Communication skills

6.4 GLOSSARY OF TERMS

The following technical terms are used in this course, and you should be familiar with these terms and their meanings.

Load losses; discharge co-efficient, friction factor, venture pipe and orifice pipe.

Test bench pumps; pump efficiency, torque, impeller, centrifugal pump relations, affinity laws and NPSH.

Heat exchanger; heat transfer coefficient.

Sources used for the compilation of the glossary: Fluid flow for Chemical Engineers by H. Randall

7. ASSESSMENT RECORDS

The following guideline for the preparation of report writing are attached to serve as examples of the implementation of the assessment criteria and assessment method, as listed in the table 3.1, and you should be familiar with these examples to prepare and orientate yourself of how the various assessment criteria are used and applied in the various assessment methods.

DEPARTMENT OF CHEMICAL ENGINEERING

FACULTY OF ENGINEERING

DEPARTMENT OF CHEMICAL

ENGINEERING

FLUIDFLOW PRACTICAL MANUAL

1. INTRODUCTION

The transport of fluid (liquid or gas) in closed conduits (commonly called pipe if it is of round cross sectional area or duct if it is not round) is extremely important in our daily operations. There is a variety of application of pipe flow with a range of very large constructed pipelines, consider the pipelines carrying crude oil from oil rigs in the sea being pumped inland for hundreds of kilometers, to a complex human being’s blood and respiratory systems. (You can think of many applications between the two extremes)

2. LAMINAR, TRANSITIONAL AND TURBULENT FLOWS

The flow of a fluid in a pipe may be laminar flow or it may be a turbulent flow. Osborne Reynolds conducted a simple experiment of injecting a neutrally buoyant dye in a pipe of diameter D carrying water with velocity V and observed the characteristics or behavior of the fluid at very low flow rate, larger “intermediate flow rate” and large enough flow rate and later denoted the three characteristics as laminar, transitional and turbulent flow, respectively. The flow in a round pipe is laminar if Reynolds number is less than approximately 2100 and turbulent if it is greater than 4000. For Reynolds numbers between the two limits, the flow is in a transitional flow.

3. GENERAL FORMULAE TO BE USED FOR THE HEAD LOSSES EQUIPMENT.

NOTE: The drop in pressure, discharge coefficient and friction factor will calculated by using the formulae:

i. (bar)

where:

P = pressure drop (bar)

L = length of pipeline (m)

D = diameter of pipeline (m)

V= mean velocity of the fluid (m/s)

F = dimensionless friction factor

ρ = density of the fluid (kg/m3)

ii.

where:

= discharge coefficient

Q = volumetric flow rate

g = gravity

iii.

where:

K = friction factor

4. PIPE DIMENSIONS

COMPONENT INNER DIAMETER (mm) OUTER DIAMETER(mm)

S.S Pipe DN 15 d = 18.10

S.S Pipe DN 20 d = 23.70

Cal. Orifice DN 25 d = 20.65

Venturi tube DN 25 d = 16.00

U bends d = 30.50

L bends d = 30.50

Enlargement d = 18.10 D = 30.50

Contraction D = 30.50 d = 18.10

The distance between the measure points for all the tubes is 800mm.

5. PROCEDURE

Fill the tank with water.

Connect the pilot plant to the compressed air line.

Set the pressure of the pilot plant at 1.4 bar (plant’s operational pressure).

Connect the plant to the power supply.

Insert the E.L.C.B.

Start the pump by switching G1 from position 0 to position 1.

Increase or decrease the flow rate by pressing the ▲▼ from control panel.

The pressure can be read either from the mercury manometer or from the computer, depending on whether the plant is operated manually or automatically via the computer.

Depending on the plant operation again, the pump output can either be read off from the control panel or the computer.

6. STOPPING THE PLANT

Stop pump G1 by switching to position 0.

Switch off the main switch.

Disconnect the plant from the main power supply.

Close the feed of the compressed air.

Drain the tank by opening the drain valve.

7. EMERGENCY STOP

Press the red mushroom-head pushbutton.

8. PURPOSE

(a) Familiarize with methodology of determining the pressure drop experimentally.(b) To determine the discharge coefficient, load and frictional losses on venture pipe and

orifice plate.(c) To determine load and frictional losses on DN15 straight pipe, DN25 straight pipe, U-

bend pipe, L-bend pipe, contraction pipe and enlargement pipe.(d) To compare experimentally determined pressure drop with the calculated one from

equation.

Reference:

ElecttronicaVeneta & Inel Spa, 31045 Motta Di Livenza (Treviso) Italy. Unit for the study of load losses pilot plant

Compiled 2006 by: Molelekoa Mosesane

Revised 2007 by: Victor Hlongwane

PUMP TEST BENCH

AIM: CHARACTERIZATION OF THE PLANT.

INTRODUCTION.

The liquid transfer and circulation in piping is a problem of main importance for normal civil applications (e.g. waterworks) as well as for the industry. It follows that it is important to know the mechanisms of fluid transfer.

PUMP TEST BENCH BACKGROUND THEORY.

The pump test bench plant (or any plant operated with multiple pumps) can be characterized by the regulation of the following manipulated variables:

The total head (H)

The power required to spin the shaft (Nshaft)

The power required to move the fluid (Nfluid)

The efficiency (η)

These variables are taken indirectly from the following controlled variables:

The discharge pressure of the pump (Pdischarge)

The suction pressure (Psuction)

The flow rate (Q)

The revolution per minute of the pump (rpm)

The torque of the pump (C)

The formulae that gave us consent to detect, via the controlled variables, the manipulated variables, have the following:

in (kW) (1)

Where:

H is the head calculated as (Pdischarge - Psuction)*10 and expressed in meters of water column;

Q is the flow rate expressed in m3/s; ρ is the density of water, equal to 998 kg/m3 @ 22°C; 102 is the conversion factor.

in (W)

(2)

Where:

n is the rpm; C is the torque given by: arm weight * length, expressed in kg.m.

(3)

The measurement will be made by changing the pump speed, i.e. the rpm and, different flow rate will be set for each constant speed value. The following variables will be detected for each of these conditions:

Variable measurement weight

Arm length, constant @ 0.05m Suction pressure via manovacuometer, range: 1-3 bar Discharge pressure via pressure gauge, range: 0-6 bar Motor rotation speed of the pump G2, set via a digital revolution counter, range: 0-

3000rpm Pumps flow rate measured with two flow meters, measurement range: 600-6000l/h and

1000-10000l/h.

BY CHARACTERIZING THE CONTROLLED AND MANIPULATED VARIABLES, THE FOLLOWING TASKS CAN BE EXECUTED.

Pump efficiency Behavior of the efficiency (%) as a function of flow rate (Q in l/h) for fixed revolutions

per minute (e.g. 2800rpm). Behaviour of the efficiency (%) as a function of flow rate (Q in l/h) for a range of

revolutions per minute (e.g. 29rpm – 3000rpm). Pressure developed (P in mH2O) as a function of flow rate (Q in l/h) for a range of

revolutions per minute (e.g 20rpm – 3500rpm). Pressure developed (P in mH2O) as a function of flow rate (Q in l/h) for fixed

revolutions per minute (2900rpm.

Pressure developed by pumps G1 and G2 in series versus pump G2 at constant speed of 2900rpm.

Pressure developed by pumps G1 and G2 in parallel versus pump G2 at constant speed of 2900rpm.

CENTRIFUGAL PUMP RELATIONS.

The power PE required in an ideal centrifugal pump can be expected to be a function of the liquid density ρ, the impeller diameter D and the rotational speed of the impeller N. The relationship is assumed to be given by the equation:

(4)

Where C1 is a constant which depends on the geometry of the system. The power PE is also proportional to the product of the volumetric flow rate Q and the total head Δh developed by the pump given by:

(5)

Using pump G2, prove that the two equations are consistent. What conclusions can you make from your experiment? Keep the speed of pump constant at 2800rpm.

The specific speed.

The specific speed is used as an index of pump type and is always evaluated at the best efficiency point of the pump, given by:

(6)

(N.B) All units must be consistent and in S.I units.

Determine the specific speed of pump G2.

Two pumps are said to be geometrically similar when the ratios of corresponding dimensions in one pump are equal to those of the other pump. Geometrically similar pumps are said to be homologous. A set of equations known as the affinity laws govern the performance of homologous pumps at various speeds.

Affinity laws

Consider a centrifugal pump with an impeller diameter D1 operating at a rotational speed N1 and developing a total head Δh1. Consider an homologous pump with an impeller diameter D2 operating at a rotational speed N2 and developing a total head Δh2.

The following relations can be made:

(7)

and

(8)

Similarly:

(9)

and by analogy with (8) the net positive suction heads for the two pumps can be related by the equation;

(10)

A centrifugal pump with an impeller diameter 0.05m has the following performance data when pumping water at the best efficiency point:

Impeller speed N =2800rpm

Capacity Q =10000l/hr

Total head Δh =15.6m

Required net positive suction head NPSH =2m

Brake power PB =8000W

Evaluate the performance characteristics of a homologous pump with ¾ the impeller diameter operating at half the impeller speed.

START UP AND RUNNING.

USE OF PUMPS INDIVIDUALLY.

PUMP G1.

Shut off valves V1, V6 and V9. Open valves V2, V7 and V10. Fill tank D1 with tap water. Open valve V4 and fill the suction pipe of the pump with water. Shut off valve V4. Insert the E.L.C.B Start pump G1 pushing the relative green pushbutton. Adjust the flow rate Q using valve V10 and read the value on the flow meter FI1. Detect the discharge pressure value on the pressure gauge PI2. Detect the suction pressure value on the pressure gauge PI1.

PUMP G2.

Shut off valves V1, V6 and V9. Open valves V3, V8 and V11. Fill tank D1 with tap water. Open valve V5 and fill the suction pipe of the pump with water. Shut off valve V5. Insert the E.L.C.B Start pump G2 pushing the relative pushbutton. Fix the rpm (e.g. 1500 rpm) using the potentiometer. Adjust the flow rate using valve V11 or the potentiometer and read the value on the

flow meter FI2. Detect the value of the torque C. Detect the discharge pressure value on the pressure gauge PI4. Detect the suction pressure value on the pressure gauge PI3.

PUMPS G1 AND G2 IN SERIES.

Shut off valves V1, V6, V7 and V11. Open valves V2, V3, V6, V8 and V11. Fill the tank D1 with tap water. Open valve V4 and fill the suction pipe of pump G2 with water. Shut off valve V5. Insert the E.L.C.B Start pump G1 pushing the relative green pushbutton. Start pump G2. Fix the rpm (e.g. 1500rpm) using the potentiometer. Adjust the flow rate Q via valve V11 reading the value fixed on the flow meter FI2.

Detect the discharge pressure gauge PI4. Detect the suction pressure value via the vacuum meter PI3.

PUMPS G1 AND G2 IN PARALLEL.

Fill the tank D1 with tap water. Shut off V1, V6 and V9. Open valve V4 and fill the suction pipe of the pump G1 with water. Shut off valve V4. Open valve V5 and fill the suction pipe of the pump G2 with water. Shut off valve V5. Insert the E.L.C.B Start pump G1 pushing the relative green pushbutton. Start pump G2 pushing the relative green pushbutton. Fix the rpm (e.g. 29rpm) using the potentiometer. Open valve V9 and after close valve V10 to configure the pumps in parallel. Adjust the flow rate via valve V11 and reading the value fixed on the flow meter FI2. Detect the suction pressure value via the pressure gauge PI1 and PI3. Detect the discharge pressure value in the pressure gauge PI2 and PI4.

STOP AND EMERGENCY STOP.

STOPStop pump G1 and G2 pushing the relative red pushbutton.Switch off the E.L.C.BFor long stop period, drain tank D1 and disconnect the plant from the electrical

supply.

EMERGENCY STOP. Push the emergency pushbutton.

Reference:

Holland F.A and Bragg R. Fluid flow for Chemical Engineers 1995, 152 – 154

ElecttronicaVeneta & Inel Spa, 31045 Motta Di Livenza (Treviso) Italy. Test bench pump pilot plant

Compiled by: Molelekoa Mosesane

DEPARTMENT OF CHEMICAL ENGINEERING

HEAT TRANSFER PILOT PLANT (SCVT) MANUAL

1. INTRODUCTION

Almost all operations of chemical engineering involve energy conversions, generating and transferring heat. Therefore it is important to know how heat can be transferred between the various systems.

In industry heat can be transferred from a fluid to another through various appliances: the most important ones are heat exchangers; modern technology has developed several types of these devices according to whether heat must be transferred between liquids, between liquids and gases or vapour, or between gases.

2. HEAT TRANSFER

In thermodynamics, energy can be transferred between two bodies also as heat: this type of transfer occurs thanks to a difference in temperature. The heat can be defined as the energy which can be transferred due to difference in temperature between two bodies. This energy is carried out through three distinct mechanisms, that is:

a. Heat conductionb. Heat convectionc. Heat radiation

In the manual only heat of conduction and convection are treated because both these phenomena need a material support, that is, they occur in the mass of a body.

3. HEAT CONDUCTION

Heat conduction is that type of heat transfer concerning heat exchangers without macroscopic movement of matter. This phenomena absolutely occurs in solid bodies where there is no relative movement of mass particles. The phenomena of heat conduction are regulated by Fourier law.

(1)

Where:

transferred heat W

thickness of the body m

temperature °C

= tempetature °C

exchange surface m2

coefficient of thermal conductivity W/m°C

4. HEAT CONVECTION

Heat convection is the type of heat transfer occurring particularly in liquids and gases. The transport of thermal energy to the different points of the body occurs with a contemporary movement of the mass particles forming the same body.

There are two types:

a. Natural convection: occurs when the movement of matter inside the mass of the

body is provoked by the transport of thermal energy.

b. Forced convection: occurring when the movement of matter inside the mass is provoked by the external by the external factors (for example, by the difference of pressure).

The phenomena of heat convection interesting this plant are those concerning the heat transfer between a solid surface and a fluid skimming this surface. This manual will deal with forced convection because only this type of heat transfer is developed in the heat exchangers of the pilot plant SCTA.

The heat flow transferred between a surface and a fluid skimming it can be expressed by Newton’s law:

(2)

Where:

coefficient of heat convection.

surface skimmed by the fluid.

temperature of the skimmed surface.

temperature of the fluid skimming the surface.

5. Tasks to be performed.a. Spiral exchanger with counter-current flows.

Calculate dTmlg.

Do the heat balance. Calculate the overall heat transfer coefficient.

b. Spiral exchanger with co-current flows.

Calculate dTmlg.

Do the heat balance. Calculate the overall heat transfer coefficient.

c. Shell and tube exchanger with counter-current flows Calculate dTmlg.

Do the R and S calculations and determine Ft. Do the heat balance. Calculation the overall heat transfer coefficient.

d. Shell and tube heat exchanger with co-current flows. Calculate dTmlg. Do the R and S calculations and determine Ft. Do the heat balance. Calculate the overall heat transfer coefficient.

e. Plate heat exchanger with counter-current flows. Calculate dTmlg. Do the heat balance. Calculate the overall heat transfer coefficient.

6. START UP

Connect the plant to the mains: single phase + G; Pmax=1kW.

Connect the plant to the main water (valve FV2): max. consumption = 1000l/h, Pmax=2 bar.

Connect the plant to the mod. SCT01/EV or to a hot water line through the black rubber hose (valve FV1): max. consumption = 1000l/h, Pmax= 2 bar.

Connect the plant to the compressed air line: max. consumption = 10Nm3/h; Set the pressure reducer under the switch board at P=1.4 bar.

Insert the E.L.C.B.

Switch the selector AUT/PC in AUT position.

Close valves V14, V15, V16, V17 and V18.

Set the hot and cold water flow rates using the PID controllers:

a. Flow rate manual control.

Switch the loop of the controller n° 1 (for the hot water) or n° 2 (for the cold water) in manual mode with the pushbutton.

Select the Out with the Ind pushbutton.

Set the Out (proportional to the opening of valve FV1 or FV2) for example at 50% with the pushbutton ▲▼.

Adjust the flow rate varying the Out with the pushbutton ▲▼.

b. Flow rate automatic control.

Adjust the flow rate of hot and cold water in manual mode (see flow rate manual control).

Select the set point with pushbutton SP-W.

Set the value of set point with pushbutton ▲▼ for example at 60%, equal to 600l/h).

Switch the loop in automatic mode with the pushbutton M/A/C (green led on).

Adjust, if necessary, the value of gain and integral time of controller.

i. Connect the spiral exchanger E3 with co-current flows.

Open the valve V1, V4, V5, V8 and V9.

Close valves V2, V3, V6, V7, V10, V11, V12, V13, V14, V15, V16, V17 and V18.

Set the hot water flow rate ( e.g 500l/h)

Set the cold water flow rate ( e.g 500l/h)

Wait a few minutes until the temperatures TI1, TI2, TI3 and TI4 are stabilized; take note of the experimental data.

Vary the flow rate of the fluids up to the desired value, wait some minutes and take note of the experimental data.

ii. Connecting the shell-and-tube exchanger E2 with co-current flows

Open the valves V2, V4, V5, V10 and V11.

Close the valves V1, V3, V6, V7, V8, V9, V12, V13, V14, V15, V16, V17 and V18.


Set the cold water flow rate (e.g 500l/h)

Wait some minutes until the temperatures TI5, TI6, TI7 and TI8 are stabilized; take note of the experimental data.

Vary the flow rate of the two fluids up to the desired value, wait some minutes and take note of the experimental data.

iii. Connecting the plate exchanger E3 with co-current flows.







iii. Connecting the spiral the spiral exchanger E1 with counter-current flows.



Set the hot water flow rate (e.g 500l/h).

Set the cold water flow rate (e.g 500l/h).



iv. Connecting the shell-and-tube exchanger E2 with counter-current flows

Open the valves V2, V6, V7, V10 and V11. Close the valves V1, V3, V4, V5, V8, V9, V12, V13, V14, V15, V16, V17

and V18.





Connecting the plate exchanger E3 with counter-current flows.







7. STOPPING THE PLANT

Close the pneumatic valve FV1.

Close the pneumatic valve FV2.

Close the main valve of hot water.

Close the main valve of cold water.

Connect the valves V14, V15, V16, V17 and V18 with a plastic hose to a drain.

Drain the water of the exchangers opening the valves V14, V15, V16, V17 and V18.

Disconnect the plant from the power supply.

Close the feed of the compressor.

8. EMERGENCY STOP.

Press the mushroom-head pushbutton.

Reference

ElecttronicaVeneta & Inel Spa, 31045 Motta Di Livenza (Treviso) Italy. Heat transfer pilot plant

COMPILED 2007 BY: MOLELEKOA MOSESANE

REVISED 2008 BY: MARCUS RANYAOA

FACULTY OF ENGINEERING AND BUILT

ENVIRONMENT

DEPATMENT OF CHEMICAL AND METALLURGICAL ENGINEERING

5. LABORATORY RULES AND RESPONSABILITIES

5.1 BASIC RULES

Always wear a laboratory coat. Do not wear open shoes. Do not eat or drink in the laboratory. No horse-playing in the laboratory. Always as the technician if you are not sure about anything.

5.2 RESPONSABILITIES

It is the students responsibility to make sure that she/he attends the practical sessions, signs the attendance register, write practical report and submit on given due dates; as this is crucial to succeed in this course.

Make sure that the engineering reports submitted are typed and binded.

6. OBJECTIVES

This practical experiment is to familiarize students with the operation of heat exchanger. Students should be exposed to /or learn the following under the different operating conditions:

a) Heat transfer under parallel and counter flow.b) Effect of different flow rates and temperature on rate of heat transfer.c) Effect of different flow rates and temperatures on heat transfer coefficient.

54

6.1 THE FOLLOWING TASKS CAN BE PERFOMED

Determine:a) The heat transfer rate of the heat exchanger.b) The overall heat transfer coefficient.c) The heat exchanger effectiveness at steady-state operation under the experimental

conditions(counter and parallel).

Reference:

Essom Company Limited, 510/1 Taksin RD., SOI 22/1. Bukkalo Thonburi, Bankok 10600, Thailand, Tel, +66(0)24760034 FAX +66(0)24761500

Compiled by Mavuse SE, 03/2010

Rivised by Molelekoa Mosesane, 06/2010

FACULTY OF ENGINEERING

DEPARTMENT OF CHEMICAL AND METALLURGICAL ENGINEERING

CHEMICAL ENGINEERING LABORATORY

EXPERIMENT: _________________________________________________________________

Name: ________________________________________________________________________

Student Number: _______________________________________________________________

Group: _______________________________________________________________________

Date Experiment Performed: ______________________________________________________

Date Experiment Submitted: ______________________________________________________

Signature: ____________________________________________________________________

Submitted to: _________________________________________________________________

%

TSHWANEUNIVERSITY OF TECHNOLOGY

DEPARTMENT OF CHEMICAL AND METTALURGICAL ENGINEERING

REPORT GRADING FORM

Name of Student: ______________________________________________________________

Student Number: ______________________________________________________________

Title of Report: ________________________________________________________________

Term: ______________________________ DATE:______________________________

Subject Max Mark Actual Mark

1. Title Page 1

2. Abstract 6

3. Introduction 2

4. Theoretical Background 3

5. Procedure 2

6. Results 6

7. Discussion of Results 10

8. Conclusion and Recommendations 4

9. Literature Cited 1

10. Nomenclature 1

11. Organization and Neatness 2

AppendixA1 Raw Data 2A2 Data analysis and Sample

Calculations10

TOTAL 50

Lab technician/Lab assistant:_____________________________________________________

Signed: ______________________________________________________________________

Comments:

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