PROJECT REPORT FOR MIDTERM

U-TUBE SHELL-AND-TUBE HEAT EXCHANGER

Program: Material Engineering

Lecturer: Adri Maldi

By:

Imam Nurhidayat (004201300023)

Major: Industrial Engineering

PRESIDENT UNIVERSITY

Jababeka Education Park Jl. Ki Hajar Dewantara, Kota Jababeka, Cikarang Baru, Bekasi, Jawa Barat

17550 Telp. (021) 8910 9762-63, Fax: (021) 8910 9768

E-mail: enrollment@president.ac.id, http://www.president.ac.id

2014

CONTENTS

I. INTRODUCTION...........................................................................................3

1.1. Heat exchanger...................................................................................................3

1.2. Purpose...............................................................................................................4

1.3. Objectives...........................................................................................................4

II. FINDINGS.......................................................................................................5

2.1. Heat Exchanger Structure...................................................................................5

2.1.1. Front Shell................................................................................................6

2.1.2. Main Shell................................................................................................7

2.1.3. Tube..........................................................................................................7

2.2. Tools and Material..............................................................................................8

2.2.1. Material Requirement..............................................................................8

2.2.1.1. Shell Units..........................................................................................8

2.2.1.2. Tube Units..........................................................................................9

2.2.2. Tools.........................................................................................................9

2.3. Manufacturing Process.....................................................................................10

2.3.1. Shell Units..............................................................................................10

2.3.1.1. Shell body.........................................................................................10

2.3.1.2. Shell copes........................................................................................12

2.3.1.3. Shell port..........................................................................................12

2.3.2. Tube Units..............................................................................................12

2.3.2.1. Tube sheet.........................................................................................12

2.3.2.2. Baffles..............................................................................................14

2.3.2.3. Tubes................................................................................................14

2.3.3. Assembly.................................................................................................16

III. CLOSING......................................................................................................18

REFFERENCE.....................................................................................................20

I. INTRODUCTION

I.1. Heat exchanger

When we use a machine or we use a car, the engine producing power and heat.

The heat that produces has a good impact to the machine itself, but how about the heat

is too much (over heating). This condition makes the engine works not well. For

example when the car engine gets overheating, then, the piston will stop moving, and

the car will suddenly stop. We need to wait the engine cold to make it works again

and it needs more time. Imagine that condition happens in a factory machine that used

to mass production and it stops working. The company wills loss the profit, and that is

not good for business. Because of those reason, the engine temperature should be

maintain to avoid the overheating. One of the tools to do this is by using heat

exchanger.

Heat exchanger is a product that used to transfer heat. The heat exchanger can

be by air or water, but usually in an engine that need fast cooling, they using the

water. This water will absorb the heat from the engine. The problem is, when the

water getting hot and touch its boiled point, the water cannot absorb the heat any

more. The only way to avoid this is to change the water with the cold one, but it will

need a lots of water resources to do. To keep the cost still low, we cooling the water

that already use. In this case of heat exchanger, we will cold down the water that

already used to be the water that can absorb the heat again.

To cooling the water we can use many types of heat exchanger. Like in cars,

they use radiator, so the hot water will enter the top side of radiator, then the water

will flow down to the bottom side, and it’s already cold because during the flow, the

heat in the water transferred to the air outside. This is the same thing, how shell-and-

tube heat exchanger works. The hot fluid will enter the fluid inlet and it will come out

in outlet port coldly.

The transfer is happens during the fluid flow through the shell. Like the figure

below:

Figure 1. Shell-and-tubes heat exchanger

I.2. Purpose

This project is to know how to build the shell-and-tube heat exchanger and

also its criteria.

I.3. Objectives

This project will lead the students to know:

a. How to choose the right raw material.

b. How to manufacture thing (heat exchanger).

c. How to consider the cost and price of a product.

II. FINDINGS

II.1.Heat Exchanger Structure

Figure 2. U-tube shell-and-tubes heat exchanger

The shell-and-tubes heat exchanger is one of the popular heat exchanger that

used widely. This heat exchanger has U-shape tubes and it’s clamped to the fixed

tube sheet. This can be used at very high temperatures and pressures without any

thermal stresses. Thus reason is avoiding damage occurring on the tube/tube sheet

connection. This heat exchanger can be used for the partial or full condensation of

gases and vapors but also as a fluid cooler/heater.

The tube/tube sheet of the internal tubes, bent in U-shape will be produced by

tube expand rolling’s. It also can be done by tube welding’s in accordance with the

construction regulations, material combinations and operating media. Naturally, to

avoid gap corrosion, after a tube welding the internal tubes are roll expanded again.

The connection chamber/tube can be produced by a tube side two-pass or multiphase

design and whose selection is effected in accordance with the standards required and

in accordance with fluid engineering aspects. Venting and draining points as well as

a corresponding foot construction are designed in relation to the installation position.

II.1.1.Front Shell

Figure 3. U-tube shell-and-tubes heat exchanger’s front shell unit

The front shell is the place where the coolant in and out, and also the

place where the gate to the tubes. This part divided into two chambers, which

is cold/in and hot/out. The chamber is used to reduce the flow speed of the

coolant, so when its speed is slow, it makes the thermal transfer more effective

(according to the thermal theory Q = m. C. ɅT, where the ɅT is the

temperature changing in which the longer the time, the higher temperature

increase/transferred)

II.1.2.Main Shell

The main shell is the place where the liquid flow and the heat that exist

will absorbed by the coolant in the tubes.

Figure 4. U-tube shell-and-tubes heat exchanger’s main/rear shell unit

II.1.3.Tube

Figure 5. U-tube shell-and-tubes heat exchanger’s tube unit

The tube is the place where the coolant flows in. The coolant will flow

through and absorb the thermal of the liquid outside the tube. This is the

process of heat exchanging is happens.

II.2.Tools and Material

II.2.1.Material Requirement

The material needed to build heat exchanger is depends on the needs. It

is makes us to divided the material into some group based on the part needed.

In accordance with the respective regulations, construction regulations and

operating media carbon steels, stainless steels as well as nonferrous heavy

metals are used. The reasonable integration of special materials, plating’s and

coatings is possible.

II.2.1.1. Shell Units

For the shell units (front, rear, ports, and flange) we will use the

carbon steel material. This material used because it’s corrosion

resistant is quiet high, can be a good choice in industrial environments

that experience high temperatures or very low pH. Carbon steel is

very durable making it perfect to use in industries like building and

manufacturing. It is also very resistant to natural disasters due to its

strength and the fact that it is quite resistant to shock.

Carbon steel pipes have high tensile strength, meaning they can

withstand the same amount of pressure as other pipes while being

thinner in construction. This gives carbon steel a greater carrying

capacity and makes it more cost-effective. Other advantages of carbon

steel include the fact that it is recyclable, making it cost effective and

energy efficient.

In the design installed in soil and water, corrosion is taken into

consideration through dimensioning of the wall thickness and

protective coatings. Recommended corrosion allowances for different

soil and water conditions are presented in the standard EN 1993-5

Eurocode 3, ‘Design of steel structures, Part 5: Piling’.

II.2.1.2. Tube Units

a. Tube Sheet

The tube sheet is a very critical part in this product. The

sheet is the tube holder, the coolant gates, and the separator

between front and rear chamber. This part should be resistant of

corrosion, and low thermal expansion. That is why stainless steels

are applied to this part. The stainless steel is very corrosion

resistant and does not contaminating the environments. It has

thermal expansion coefficient from 10 x 10-6 until 17 x 10-6 / 0C.

This reason makes the material more stable when used in high

temperature and long operation.

b. Baffles

As the separator of flow, baffles should have good corrosion

resistants’ and low thermal expansion to avoid leaking. That is

why we choose the same material like tube sheet as the material

for baffles.

c. Tubes

Tubes as the main part where the coolant flow, it has to be

very high corrosion resistant and also high elasticity. This

specification is to support when the bending process, so the tube

not broken. Also, because of the tube diameter is small and if the

corrosion happens it makes the diameter getting smaller. To make

the bending process is save, we use the Copper red Brass Al-

Bronze which has elasticity modulus of 17 in 210C it makes the

material is not broken when bended.

II.2.2.Tools

The tools that we can used to manufacture the heat exchanger are:

a. Roller machine

b. Arc welding tools

c. Sawing machine

d. Punch and Dies machine

e. Drilling Machine

f. Bending machine

g. Clamp

II.3.Manufacturing Process

II.3.1.Shell Units

II.3.1.1. Shell body

a. Rolling and welding

A

Welding

Rolling machine

Shell cylinder

Operator

B

Figure 6. a) Rolling machine, b) Shell processing layout

The process above, is the making the shell body. In this step,

the process is start from sheet steel from steel manufacturing. Then

the sheet will rolled like the picture above with the diameter

required (Ø 1000 mm). Then in the end of rolling it will directly

welded to make the cylinder connected.

To prevent the corrosion or lack, in the finishing process, the

shell will coated with another material, such as Galvanizing is a

electrochemical plating of highly corrosion resistant material on

the surface of another metal. This technique is widely used to coat

zinc over the iron and steel. Galvanized sheet metals are available

in the market for their commercial use. This technique is very

popular and widely accepted due its effectiveness and economy.

b. Cutting

Figure 7. Shell cutting process

In this process, the cylinder will cut according to the length

requirement (2000 mm). Also it will cut in to two parts which are

the front shell and the rear/main shell. The cutting tools we used

for shell cutting is by arc welding cut. The reason why we use this

is because the thickness of the shell. Besides that, if we used

sawing machine it will be very big machine to do, so we use an arc

welding cut.

c. Drilling

As the product design, which is we need two ports in each

shell parts, in this section, the shell will drilled according to the

port diameter.

II.3.1.2. Shell copes

First of all, we cut the metal sheet in to the size required. After

that the shell cope process will punch into the doom-shaped. After

punched, it will cut to make the boundaries tight.

II.3.1.3. Shell port

To make the shell port, we need some short pipes attached in

the shell body. This pipe material is same like the shell. Before

attaching process, the pipe will cut properly to fit with the shell body.

Then, we make holes on the shell body using drilling machine. The

shell will drill so it can be fit to the pipe. To attach the pipes (ports)

we use arc welding process because the material is thick.

II.3.2.Tube Units

II.3.2.1. Tube sheet

The tube sheet is processed using CNC machine. The first step

is circular cutting, so the metal works will cut into circular shape with

the diameter fit to the sheet.

Figure 8. Circle cut metal for tube sheet

From the cutting process, then start to drilling process, the

drilling has four kind of position like the figure below:

A b

Figure 9. a) Tube sheet layer types, b) Drilling process

Figure 10. Tube Sheet after drilling

II.3.2.2. Baffles

The process to make the baffles is actually same like the tube

sheet. The additional work is to cut the layer after it finish. This

cutting also considers the flow of the liquid like figure below:

Figure 9. The effect of baffle cutting to the liquid flow

II.3.2.3. Tubes

a. Rolling

The tubes are from ingots and then rolled in to a billets part.

After that, the billet will rolled again into pipe shape, shown

below:

Figure 10. Tube making by rolling

b. Cutting

After rolling process, then the tube will cut into 20 tubes

with required length. Using the sewing machine, the tube will cut

into the required length.

c. Bending

Then, the tube will bended in to U-shaped tube. The bending

itself has many types, like, press bending, circular bending, tension

bending, etc. in this process we will use the rotate bending like

figure below:

Figure 11. Bending process

II.3.3.Assembly

II.3.3.1. Shell Units Assembly

a. Shell cope attaching

The assembly for this step is to close the shell end using the

shell cope. The assembly will held using welding process. The

welding process is chosen because of its ability to join the parts in

once. Compare with using flange, the welding does not need any

mounting bolt, sealer, and it is well coated.

b. Flange attaching

The flange attaching is in the shell end. This attached place is

at the meeting of the front shell and the rear shell. Before attached

to the shell body, the flange already drilled round as the mounting

place.

II.3.3.2. Tube Units Assembly

The tube units’ assembly consists of tube attaching and baffles

attaching. Both processes are held in one time.

Figure 12. Attaching tube to the Tube Sheet using clamp

Figure 13. Attaching the baffle to the tube

The process of attaching baffle at the tube is using gas welding

because of the material is thin. This welding is used to avoid the

liquid flow through the gap between baffles and tubes.

II.3.3.3. Final Assembly

The final assembly is the almost end of the process. This step is

to put the tubes in to the main shell and to close it by put the front

shell.

Figure 14. Final assembly

After the final assembly, the process making is done, but it

needs to be check or quality controlling.

III. CLOSING

The heat exchanger is a product used to thermal transfer that was in the liquid in

to the outside or vice versa. In this study, the heat thermal will transfer to another liquid

media (coolant) and the main liquid will rotate to the machine to control the machine

temperature. Heat exchanger has many types of products and the most common used is

shell and tubes. This type can be implementing in widely type of machine. This type

need to have good material because it works with high pressure and high temperature

media.

That is why, the heat exchanger made of carbon steel which has high corrosive

resistant and low thermal expansion as the shell. Another, we use copper alloy as the

tube because of its ability as a conductor is very good, and it also has high elasticity

coefficient, so when it bended to U-shape it does not broken.

The manufacturing process to make this product is basically simple, but the

precision is make this think little bit complicated. Here is the chart of making process:

a. Shell unit assembly

Chart 1. Shell Units Assembly

b. Tube units Assembly

Chart 2. Tube Unit Assembly

c. Final Assembly and quality controlling

Chart 3. Final Assembly

REFFERENCE

rolling (tube) / cutting (tube sheet

&baffles)

metal ingots as row material (tube)metal plate as row material (tubesheet & baffles)

rolling, cutting and bending (tube) / CNC Drilling

metal billets (tube)circular shape metal plate (Tubesheet & baffles)

Tubes Assembly

U-shaped tubesTubesheetBaffles

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