groupc

German University of Technology in Oman Department of Engineering

Project Report

Study on the effectiveness of welding

Group: C

Sara Al-Maskari 11-0092 Bashair Al-Saa’di 11-0315

Sumaiya Al-Battashi 11-0217 Balqees Al-Syiabi 11-0172

Raiya Al-Aisri 11-0216

Supervisor: Dr.-.Ing. Najah Mhanna

Date of submission: 10/2/2014

All content and results of this paper are the intellectual property of its author and/or GUtech and may not be reproduced, displayed or distributed without permission.

GUtech, Group: C Study on the effectiveness of welding 2

Table of Contents Table of Contents .................................................................................................... 2

1. List of Symbols and Abbreviations .................................................................... 3

2. List of Figures and Tables ................................................................................. 3

3. Main Chapters .................................................................................................. 4

Chapter 1 General project description .................................................................... 4

Chapter 2 Functional description of the unit ........................................................... 5

Chapter 3 Results of your work ............................................................................. 6

Chapter 4 Conclusion and outlook for Project Work II ............................................. 9

4. Statement of Authorship ................................................................................. 10

5. Self-Evaluation ............................................................................................... 11


1. List of Symbols and Abbreviations Symbol Unit Explanation T C0 The temperature. V ml \ L volume

2. List of Figures and Tables Figure 1 condenser unit 5 Figure 2 illustrate number of turns for the vapor pipe = 8 turns 6 Figure 3 500 ml flask 7 Figure 4 output - pure water 7 Figure 5 reason behind the lost of 33.8 ml 7 Figure 6 2-D sketch of condenser unit 8 Table 1 the overall output 7 Table 2 gantt-chart (steps of how we finished our condenser unit) 9


3. Main Chapters Table of Contents 2

1. List of Symbols and Abbreviations 3

2. List of Figures and Tables 3

3. Main Chapters 4

Chapter 1 General project description 4

Chapter 2 Functional description of the unit 5

Chapter 3 Results of your work 6

Chapter 4 Conclusion and outlook for Project Work II 9

4. Statement of Authorship 10

5. Self-Evaluation 11

Chapter 1 General project description In this project we are looking for the cheapest and easiest way to covert salt water

into pure water with the help of solar energy, which is clean, available and unlimited

source of energy. This project is divided into two parts the first part is evaporation part

and the second is the condensing part. In the last two semesters we worked on

evaporation part which used the solar source-sun-to heat up the sea water and

convert the liquid water into vapor. In this semester we completed the condensing

part, which is used to convert the vapor into pure water. Our aim of this part is to build

a condenser that can condense a specific amount of vapor which comes from the

evaporation part through a copper pipe by cooling the pipe in specific temperature so

the vapor will condense and transfer into pure water.


Chapter 2 Functional description of the unit

Figure 1 condenser unit Figure 1 shows the condenser unit of Group C labeled from 1 to 7:

1) A heater: is used to heat the water in order to condense it. We used it because the

evaporation unit we should use did not work.

2) Condensing pipe: here where the vapor comes from the evaporation part and

inters to the tank.

3) Tank: here where the cold water is put to exchange the heat with the vapor in

cupper pipe in order to condense.

4) Input hole: here where the cold water is interred, in order to exchange the heat with

the vapor.

5) Output hole: the cold water after while will gets warm so it will pass through this

pipe which will be connected in the evaporation unit to evaporate it again.

6) Output pipe: through this pipe the condensing pure water will go to a small tank

that the pure water is collected.

7) Stander: It helps to keep the condensing unit fixed.


Chapter 3 Results of your work Since we start working on the project at the beginning of the semester we designed the condensing unit and the calculations are prepared. Then, paced on that we start building the condensing unit. Two shoots were done in order to test the unit: 1. First attempt which took more than three hours resulting no output. The are

several reasons of why didn’t our unit worked from the first attempt: A. The main reason is we based our unit as it will condense a huge amount of

vapour as it cannot condense in (mL) it will condense in (L), due to the evaporation unit which was done by the 4th semester last year is not working the team had to replace it with a small heater which evaporate small amount of water.

B. Leaking of the cold water, where it happened in two different places due to the cold water that were in the tank. First, in the hole that the cold water is remove when it gets warm at point 5 (see figure 1). The reason behind that is we didn’t fix the valve right, but later we manage to fix it. Secondly, in the hole where the output pure water pipe pass. The reason is we as a team forgot to fix the pipe tightly with the tank.

C. Condensing pipe’s length: regarding our calculation as mentioned in part a, we put the pipe which contain the vapour needs to condense a huge amount of vapour. However, the vapour takes too long to condense, approximately it takes more than two hours.

2. Second attempt, which was been held after classes. The reason behind asking for extra hours is because as a group we didn’t accept that our unit didn’t work. With the extra hours that were spend in the project work we accomplished our aim to condense vapour. The process went as follows: A. First we had to remove all the cold water that was placed inside the tank.

Then, we fixed the valve tightly to the tank and we manage somehow to reduce the leakage that was happening in the two different places.

B. Secondly, the length of the pipe had to be reduced from huge amount of turns to 8 turns only as showing in the (figure 2).

Leaking and the length were the two problems that kept our unit to not work, but we manage to solve it and provide the suitable solutions for it.

Figure 2 illustrate number of turns for the vapor pipe = 8 turns


By the second attempt we had an output. First we use 500 ml flask as showing in the figure 3, and fill it with water that we want it to evaporate. Then, we place it in the heater to start boiling because we want the vapour. It started boiling at 100oc and start increasing the temperature until we got the vapour. Then the vapour entered the tank with the help of the copper pipe and start condensing. Once it start giving output we start the time watch. The use of the time watch t know how much time needed to condense this amount of vapour. The temperature of the vapour was approximately 130oc, while the temperature of the water in the flask reduced until 103oc and remained same. The pure water output gave us 146.2 ml per 17 mints as showing in figure 4. The amount of water left in the flask was 320 ml. Then if you took 500 ml – 320 ml you should get 180 ml of vapour. The output was 146.2 ml and the actual amount we should get supposed to be 180 ml, we lost almost 33.8 ml. The 33.8ml was lost as following reasons:

1. First not whole amount of the steam was arriving to the condensing part. A little amount of steam leaked before entering to the tank as showing in figure 5, the leaked happened from pipe 2 before entering the tank (cool box).

2. Second reason is some of the condensing steam was remaining in the copper pipe (inside the tank) which we used to condense the steam and it did not exit from the pipe because there was no pump to push the condensing steam.

The overall output (pure water): Time Amount

1 mints 8.5 ml

5 mints 42.5 ml

17 mints 146.2 ml Table 1 the overall output Table 1 show the amount of pure water output that the group got in ml per mints.

Figure 3 500 ml flask

Figure 4 output - pure water

Figure 5 reason behind the lost of 33.8 ml


How can we improve? If there is another chance to work in this project again there will be some improvements that make the project more efficient. First of all we will read and search more in thermodynamic to wide our background in heat exchange and the formulas which will help to understand how does the project work. As well as understanding the formulas will help a lot to do exact calculations and the more accurate calculations we do the more efficient project and better results we get. Also, from this unit we learned that the speed of condensing related to the size of the tank and the condenser. For example, you cannot use a huge size of condenser to condense a small amount of vapour in short period of time. It will condense but takes long time and that was our main mistake. In the future we have to design a condenser according to the amount of vapour that will be condense.

Figure 6 2-D sketch of condenser unit The figure 6 above illustrate our whole unit in two dimensional (2-D). The description of the unit was explained in chapter 2 and the process of the unit was explained clearly in chapter 3.


Chapter 4 Conclusion and outlook for Project Work II The most problem we faced was the calculation part. In fact, working of the project depends on how the calculations are specified and correct, so it tacked time and big effort until we found the right equations then getting the result. In addition, there were some technical issues for instance, in the cooling box, during the last experiment of testing function of the project the water was leaking, then we tried to stop this leaking by several materials. Moreover, we have designed the cooling box to condense a specific amount litters (L) of water from evaporation part, but the amount of steam reduced, then we reduced number of turns. Each member was helpful with her colleges in the group and taken her responsibility, so this help the group to communicate and share the ideas easily, while this condition made an active environment during the semester. Likewise, our time management was good; we could manage the time and end up with each part on its particular period as we planned at the beginning. In fact, we had some doubts during the semester we can avoid them next time for instance, it is really important to read a lot in thermodynamic topics in order to improve our background in the idea of evaporation and condensation process. This may guide us to know the exact calculations we need to do. This experience adds some useful technical skills to us for example; we have learned how to use several machines and devises, so during our working in the workshop we were able to deal with these machines. Also, working as a group teach us skills in how the member can communicate with the other members and share here ideas then at the end agree about one idea, this makes the way of thinking more flexible. Moreover during our research in order to do the calculations we got new information for instance, about how much amount of steam could be condensed in specific time.

Extra class

th 9class

th 8class

th 5class

th 4class

rd 3class

nd 2class

st 1class

needs task

Wood, work shop tools

Building the standard

A

Cooling box, copper flexible pipe, funnel, work shop tools

Making the condenser

B

Boiler, stopwatch, water

Testing the condenser

C

Boiler, stopwatch, water

Final test D

Table 2 gantt-chart (steps of how we finished our condenser unit)


4. Statement of Authorship I hereby confirm that I am author of this work and that all sources used are properly stated. When used, Ideas and concepts developed by others are clearly marked as such. I affirm that this work has not been submitted elsewhere for a similar purpose. ___________________________________________________________________ Sara Al-Maskari, GUtech, 10/2/2014, ___________________________________________________________________ Sumaiya Al-Battashi, GUtech, 10/2/2014, ___________________________________________________________________ Bshaiyer Al-Sa’adi, GUtech, 10/2/2014, ___________________________________________________________________ Balqees Al-Siyabi, GUtech, 10/2/2014, ___________________________________________________________________ Raiya AL-Aisri, GUtech, 10/2/2014,


5. Self-Evaluation

Name Grade Sara Al-Maskari A+ Sumaiya Al-Battashi A+ Bshaiyer Al-Sa’adi A+ Balqees Al-Siyabi A+ Raiya AL-Aisri A+

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