Difference between revisions of "Biogas-Plant/C3/Construction-of-the-Dome/English"

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Line 12: Line 12:
  
  
Welcome to this '''Spoken Tutorial'''on-
+
Welcome to this '''Spoken Tutorial''' on-
  
 
* Construction of the dome of the Digester tank.
 
* Construction of the dome of the Digester tank.
Line 36: Line 36:
 
We will learn:
 
We will learn:
  
The step-by-step procedure for constructing a dome.
+
*The step-by-step procedure for constructing a dome.
 
| style="background-color:transparent;border:0.75pt solid #000000;padding:0.071cm;"| In this '''tutorial''', we will learn-  
 
| style="background-color:transparent;border:0.75pt solid #000000;padding:0.071cm;"| In this '''tutorial''', we will learn-  
  
The step-by-step procedure for constructing a dome.
+
*The step-by-step procedure for constructing a dome.
  
 
|-
 
|-
Line 131: Line 131:
 
* Around the smaller 10-inch steel rods, as shown.
 
* Around the smaller 10-inch steel rods, as shown.
  
We will need 2, 12-ft rods to complete the circle.
+
We will need two 12-ft rods to complete the circle.
  
 
|-
 
|-
Line 290: Line 290:
  
 
# The length of the steel rod would depend upon-
 
# The length of the steel rod would depend upon-
 
+
#* the position of the circular ring on the frame.
* the position of the circular ring on the frame.
+
 
+
 
# Longer steel rods would be required-  
 
# Longer steel rods would be required-  
 
+
#* as we gradually go from top to bottom.
* as we gradually go from top to bottom.
+
  
 
|-
 
|-
Line 309: Line 306:
 
| style="background-color:transparent;border:0.75pt solid #000000;padding:0.071cm;"| So, let’s do that.
 
| style="background-color:transparent;border:0.75pt solid #000000;padding:0.071cm;"| So, let’s do that.
  
For the first ring, which is the smallest ring at the top.
+
For the first ring,  
 
+
*which is the smallest ring at the top,
We will need approximately-
+
*we will need approximately-
 
+
** 4 ft and 7 inch steel rod (adding 2 feet extra for tying).  
* 4 ft and 7 inch steel rod (adding 2 feet extra for tying).  
+
 
+
 
* Diameter of this circular ring will be 10 inches
 
* Diameter of this circular ring will be 10 inches
  
For the second ring, we will need approximately 7 ft 1 inch of steel rod.
 
  
 +
For the second ring,
 +
*we will need approximately 7 ft 1 inch of steel rod
 
* Diameter of this ring will be 1 foot and 7 inches
 
* Diameter of this ring will be 1 foot and 7 inches
  
For the third ring, 9 ft and 8 inches steel rod would be required
 
  
 +
For the third ring,
 +
*9 ft and 8 inches steel rod would be required
 
* Diameter would be 2 ft 5 inches
 
* Diameter would be 2 ft 5 inches
  
Fourth ring will require 12 ft 3 inches long steel rod.
 
  
Diameter of this ring will be 3 ft and 3 inches
+
Fourth ring will require
 +
*12 ft 3 inches long steel rod.
 +
*Diameter of this ring will be 3 ft and 3 inches
  
Fifth ring will need 14 ft 10 inches long steel rod
 
  
 +
Fifth ring will need
 +
*14 ft 10 inches long steel rod
 
* Diameter of this ring will be 4 feet 1 inch
 
* Diameter of this ring will be 4 feet 1 inch
  
Sixth ring will require 17 feet 4 inches long rod.
 
  
 +
Sixth ring will require
 +
*17 feet 4 inches long rod.
 
* Diameter of this ring will be 4 feet and 10 inches  
 
* Diameter of this ring will be 4 feet and 10 inches  
 +
  
 
Remember-  
 
Remember-  
Line 345: Line 346:
 
* for tying the rods together with steel wires for all the 8 rings.
 
* for tying the rods together with steel wires for all the 8 rings.
  
* And the diameter for all the 8 rings-
+
* And the diameter for all the 8 rings is calculated excluding the 6 inches.
 
+
* is calculated excluding the 6 inches.
+
  
 
|-
 
|-
Line 353: Line 352:
 
| style="background-color:transparent;border:0.75pt solid #000000;padding:0.071cm;"| Now comes the 7th and 8th ring.
 
| style="background-color:transparent;border:0.75pt solid #000000;padding:0.071cm;"| Now comes the 7th and 8th ring.
  
* Both will be used for making the circular rings and also the entrance of the dome.<br/>
 
  
* Measurements for these two are- Seventh ring will require 20 ft and 10 inches long steel rod.
+
Both will be used for making the circular rings and also the entrance of the dome.<br/>
*
+
 
 +
 
 +
Measurements for these two are-  
 +
*Seventh ring will require 20 ft and 10 inches long steel rod.
 +
 
* And for eighth ring 23 ft and 5 inches long steel rod would be required.
 
* And for eighth ring 23 ft and 5 inches long steel rod would be required.
*
+
 
* Keep in mind that this includes the measurement for the bent rods as well
 
* Keep in mind that this includes the measurement for the bent rods as well
  
Line 386: Line 388:
 
Arrow at the scale fit between two circular rings
 
Arrow at the scale fit between two circular rings
 
| style="background-color:transparent;border:0.75pt solid #000000;padding:0.071cm;"| Please note, if you follow the measurements mentioned earlier-
 
| style="background-color:transparent;border:0.75pt solid #000000;padding:0.071cm;"| Please note, if you follow the measurements mentioned earlier-
 
  
 
# Then you will get a uniform distance of 8 inches between each circular ring.
 
# Then you will get a uniform distance of 8 inches between each circular ring.
 
 
# To confirm this, use a 1 foot steel scale having two hooves.  
 
# To confirm this, use a 1 foot steel scale having two hooves.  
 
 
# The distance between these two hooves should be 8 inches.
 
# The distance between these two hooves should be 8 inches.
 
 
# And it should fit in between two circular rings as shown here.
 
# And it should fit in between two circular rings as shown here.
  
Line 400: Line 398:
 
|-
 
|-
 
| style="background-color:transparent;border:0.75pt solid #000000;padding:0.071cm;"|  
 
| style="background-color:transparent;border:0.75pt solid #000000;padding:0.071cm;"|  
| style="background-color:transparent;border:0.75pt solid #000000;padding:0.071cm;"| Just after placing the 6th circular ring an important thing to be done is-
+
| style="background-color:transparent;border:0.75pt solid #000000;padding:0.071cm;"| Just after placing the 6th circular ring, an important thing to be done is-
 
+
  
 
* To fix vertical rods on the frame.
 
* To fix vertical rods on the frame.
Line 415: Line 412:
  
 
<center>[[Image:]]</center>
 
<center>[[Image:]]</center>
| style="background-color:transparent;border:0.75pt solid #000000;padding:0.071cm;"| Between two half-arches -
+
| style="background-color:transparent;border:0.75pt solid #000000;padding:0.071cm;"|  
 +
Between two half-arches -
  
 
* Fix a steel rod-
 
* Fix a steel rod-
 
+
** of length 5 ft and 5 inches, bisecting the two main arches.  
* of length 5 ft and 5 inches bisecting the two main arches.  
+
  
 
* Tie this rod using-
 
* Tie this rod using-
 
+
** steel wires from the base ring upto the first ring, as shown in the image.
* steel wires from the base ring upto the first ring as shown in the image.
+
  
 
* Similarly, fix two more steel rods
 
* Similarly, fix two more steel rods
 +
** of 4 ft and 7 inches
 +
**bisecting the half-arch and the 5 ft and 5 inches steel rod.
  
* of 4 ft and 7 inches bisecting the half-arch and the 5 ft and 5 inches steel rod.
 
  
 
Tie these two rods using steel wires from the base ring upto the second ring, as shown.  
 
Tie these two rods using steel wires from the base ring upto the second ring, as shown.  
Line 433: Line 430:
 
Please note-  
 
Please note-  
  
# Between the 5th and 6th 10 inch hammered steel rod do the following:
+
# Between the fifth and sixth 10-inch hammered steel rod, do the following:
 +
#* The 4ft 7 inches long steel rod has to be bent and tied to the 6th ring.
 +
# This is done to make space for the entrance of the dome as shown in the image.
  
# The 4ft 7 inches long steel rod has to be bent and tied to the 6th ring.
 
 
# This is done to make space for the entrance of the dome as shown in the image.
 
  
 
Note that, in both cases-
 
Note that, in both cases-
Line 449: Line 445:
  
 
However it is to be noted that -
 
However it is to be noted that -
 
+
*between 6th and 8th ring will be the gap or the entrance to the dome.
between 6th and 8th ring will be the gap or the entrance to the dome.
+
  
 
|-
 
|-
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|-
 
|-
 
| style="background-color:transparent;border:0.75pt solid #000000;padding:0.071cm;"|  
 
| style="background-color:transparent;border:0.75pt solid #000000;padding:0.071cm;"|  
| style="background-color:transparent;border:0.75pt solid #000000;padding:0.071cm;"| Use 7th and 8th ring to make the
+
| style="background-color:transparent;border:0.75pt solid #000000;padding:0.071cm;"| Use 7th and 8th ring, to make the gap of the mentioned size.
 
+
gap of the mentioned size.
+
  
 
Bend the 7th rod-
 
Bend the 7th rod-
 +
* to make the upper side of the entrance, as shown in the image.<br/>
  
* to make the upper side of the entrance, as shown in the image.<br/>
 
  
 
And bend the 8th ring downward.
 
And bend the 8th ring downward.
Line 512: Line 505:
 
|-
 
|-
 
| style="background-color:transparent;border:0.75pt solid #000000;padding:0.071cm;"|  
 
| style="background-color:transparent;border:0.75pt solid #000000;padding:0.071cm;"|  
| style="background-color:transparent;border:0.75pt solid #000000;padding:0.071cm;"| Please note- if the chicken mesh is not stretched tightly then-
+
| style="background-color:transparent;border:0.75pt solid #000000;padding:0.071cm;"| Please note-  
 
+
*if the chicken mesh is not stretched tightly then-
 
* cracks might appear later while plastering the dome.
 
* cracks might appear later while plastering the dome.
  

Latest revision as of 18:35, 27 May 2016

Visual Cue
Narration
Slide 1

Construction of the Dome

Hello everyone.


Welcome to this Spoken Tutorial on-

  • Construction of the dome of the Digester tank.
Show corresponding images
  • digging of the pit and
  • laying the foundation.
The tutorials on-
  • digging of the pit and
  • laying the foundation

are available on Spoken-tutorial.org website.

Slide 2

Construction of the Dome

We will learn:

  • The step-by-step procedure for constructing a dome.
In this tutorial, we will learn-
  • The step-by-step procedure for constructing a dome.

Slide 3 Construction of the Dome

What is a dome?

So what is a dome?
Show the animated Biogas dome Dome is
  • an arch like structure
  • placed on the Digester tank
  • where the Biogas is collected.
[[Image:]] Construction of the dome is a very interesting and important procedure.
[[Image:]]

[[Image:]]

Items used for construction are-
  • Steel rods
  • Chicken mesh and
  • Steel wire

Detailed specifications of these are mentioned-

  • In the tutorial on materials required.
Let’s begin
[[Image:]] First, make a circle of 7 feet 6 inches diameter with lime powder.

Now put 12 marks on the circumference of the circle

And number them from 1 to 12, as shown.

These 12 marks should be separated-

  • by a distance of two feet from each other.
Animation to show distance between two rods should be approx. 2 ft.
Next, hammer 12 10-inch steel rods all along the marked circumference.

Hammer the 10-inch steel rods upto 2 inches in the ground.

Remember that they have to be removed later.

[[Image:]]
[[Image:]]
Next comes the use of 12-ft long steel rods.
[[Image:]]
With the 12-ft long steel rods-
  • We’ll make an outer circle around the hammered 10-inch steel rods.
[[Image:]] I will now tell you how to make a circle using the hollow rod.

Use an iron rod having hollow ends.

With this iron rod, bend the 12-ft steel rods to form a circular shape.

[[Image:]]
Then place the circular steel rods-
  • Around the smaller 10-inch steel rods, as shown.

We will need two 12-ft rods to complete the circle.

[[Image:]]
Now tie the circular steel rods-
  • to the 10-inch steel rods using steel wires, as shown.

Ensure that the knot is tied very tightly and the steel rod circle is very stable.

This is the base of the dome.

Hence, it has to be very strong to bear the load of the plastered dome later.

[[Image:]] Now hammer a 4-ft and 2 inches long bamboo stick-
  • in the center of the circle, as shown.

Hammer the bamboo stick up to 2 inches in the ground.

Ensure that-

  • it can stand firmly by itself and
  • can be easily removed later

This bamboo stick should be able to-

  • temporarily support the frame of the dome.
Now let’s start building the frame of the dome.
Animation of the tool in the hands of the mason Again, use the hollow iron rod-
  • and bend a 12-ft long steel rod to form an arch like shape.

This arch will give the semi-circular shape to the dome.

Hence, ensure that the arch is symmetric on either side when bent.

Similarly, bend 2 more 12-ft rods to form arches.

Show a diagrammatic representation here
Let me explain-
  • Exactly how the arches have to be placed on the circumference using a diagram.
  • Secure one end of the arch at rod number 1.
  • And the other end of the arch at rod number 7.
  • This will ensure perfect symmetry to the arch
  • And it will rest on the bamboo stick in the centre.
[[Image:]]
Show arrow pointing at the bent steel rod on the bamboo stick
[[Image:]]
Use steel wires to tie-
  • The arch together with the hammered 10-inch steel rod and the circular ring.
[[Image:]]

This pic shows only the circular ring and the 10-inch steel rod being tied. Replace with a picture of arched iron rod also.

For tying, make a knot like structure with the steel wire, as shown here.
[[Image:]]


Show arrow where the bent steel rod has been tied with hammered steel rod

Do likewise at the opposite end of the arch, as well.
Next, we will tie two more arches.

Secure the second arch to rod number 3, and rod number 9.

And secure the third arch to rod number 5 and rod number11.

Image for placing the arches at an angular separation of 60 degree from the base
The 12 feet steel rod arches should be-
  • at an angular separation of 60 degrees at the base
[[Image:]]
Now, we have three arches for the frame of the dome.

Next, carefully slide the steel rods at the top-

  • Such that a small gap is left open in between.
  • Tie the steel rods using the steel wires as shown.
  • Intersection of the three arches will look like a triangle.
  • The sides of the triangle should be approximately 2.5 inches.

As shown in the image-

  • The top view of the framework should look like this after tying.
[[Image:]]
What you see here is the mason showing-
  • the exact position of the open triangular gap using the bamboo stick
  • This gap is where the main gas pipe of 1 inch diameter will fit.
[[Image:]] Once the arches have been fixed, we have to make-
  • circular rings with the remaining 12-feet steel rods.
First let us understand how to make these rings with the help of a diagram.
Need a 3D animation here. This is the framework we constructed so far-
  • circular base
  • semi-circular arches
Now we need to fix 8 circular rings such that-
  • they can be placed on the arches, as shown.

The rings have to be uniformly separated-

  • by a distance of 8 inches between each of them.
[[Image:]]
To make circular rings, start from the top and gradually move downwards.
[[Image:]]
Two things to keep in mind while making circular rings are-
  1. The length of the steel rod would depend upon-
    • the position of the circular ring on the frame.
  2. Longer steel rods would be required-
    • as we gradually go from top to bottom.
Image- mason cutting steel rod
We will first have to cut-
  • the steel rods to the required length before we fix the rings.
Need a 3D animation here of a steel rod bending to form a ring with length and diameter prominently displayed in the animation.


So, let’s do that.

For the first ring,

  • which is the smallest ring at the top,
  • we will need approximately-
    • 4 ft and 7 inch steel rod (adding 2 feet extra for tying).
  • Diameter of this circular ring will be 10 inches


For the second ring,

  • we will need approximately 7 ft 1 inch of steel rod
  • Diameter of this ring will be 1 foot and 7 inches


For the third ring,

  • 9 ft and 8 inches steel rod would be required
  • Diameter would be 2 ft 5 inches


Fourth ring will require

  • 12 ft 3 inches long steel rod.
  • Diameter of this ring will be 3 ft and 3 inches


Fifth ring will need

  • 14 ft 10 inches long steel rod
  • Diameter of this ring will be 4 feet 1 inch


Sixth ring will require

  • 17 feet 4 inches long rod.
  • Diameter of this ring will be 4 feet and 10 inches


Remember-

  • as mentioned while explaining the first circular ring
  • an extra 2 feet has been calculated-
  • for tying the rods together with steel wires for all the 8 rings.
  • And the diameter for all the 8 rings is calculated excluding the 6 inches.
Now comes the 7th and 8th ring.


Both will be used for making the circular rings and also the entrance of the dome.


Measurements for these two are-

  • Seventh ring will require 20 ft and 10 inches long steel rod.
  • And for eighth ring 23 ft and 5 inches long steel rod would be required.
  • Keep in mind that this includes the measurement for the bent rods as well
[[Image:]] As soon as three circular rings are placed-
  • An important thing to be done is-
[[Image:]]
Place 6 Bamboo sticks of-
  • Length 4 ft in an inclined position inside the frame of the dome.

Note that-

  • Bamboo sticks have to be spread out uniformly from the centre of the base.
  1. And should be firmly rested against the circular rings or the arches.
  2. These sticks will further give support to the frame of the dome.
[[Image:]]

Arrow at the scale fit between two circular rings

Please note, if you follow the measurements mentioned earlier-
  1. Then you will get a uniform distance of 8 inches between each circular ring.
  2. To confirm this, use a 1 foot steel scale having two hooves.
  3. The distance between these two hooves should be 8 inches.
  4. And it should fit in between two circular rings as shown here.

However, you may ignore minor variations, if any.

Just after placing the 6th circular ring, an important thing to be done is-
  • To fix vertical rods on the frame.
I will explain how to do that:
[[Image:]]
Saurabh: Show animation remove the image below as it already has mesh.
[[Image:]]

Between two half-arches -

  • Fix a steel rod-
    • of length 5 ft and 5 inches, bisecting the two main arches.
  • Tie this rod using-
    • steel wires from the base ring upto the first ring, as shown in the image.
  • Similarly, fix two more steel rods
    • of 4 ft and 7 inches
    • bisecting the half-arch and the 5 ft and 5 inches steel rod.


Tie these two rods using steel wires from the base ring upto the second ring, as shown.

Please note-

  1. Between the fifth and sixth 10-inch hammered steel rod, do the following:
    • The 4ft 7 inches long steel rod has to be bent and tied to the 6th ring.
  2. This is done to make space for the entrance of the dome as shown in the image.


Note that, in both cases-

  • Extra 3 inches have been left at the top.
  • For the ease of tying the steel wire to the circular rings.
Now we will fix the last two circular rings i.e. 7th and 8th ring.

However it is to be noted that -

  • between 6th and 8th ring will be the gap or the entrance to the dome.
[[Image:]]

Animation of the dome to show the gap prominently.

This gap should be big enough for the mason to enter inside the dome.

Size of this gap would be approximately-

  • 2 ft of width and
  • 2 ft of height
Use 7th and 8th ring, to make the gap of the mentioned size.

Bend the 7th rod-

  • to make the upper side of the entrance, as shown in the image.


And bend the 8th ring downward.

This will make the lower end of the gap or entrance, as shown in the image.

Now, tie the bent 7th and 8th rings firmly with steel wires
Next comes covering the frame of the dome with chicken mesh.
Use a metal scissor to cut the required size of the chicken mesh.

Start covering the frame tightly with the mesh, from top to bottom.

[[Image:]]


[[Image:]]

Show arrow at the hook

To tie the mesh to the frame-
  • stretch the mesh tightly and tie it to the frame with steel wires.

This can be done by using a metal hook.

To tighten the layers of the chicken mesh-

  1. Insert the hook into the hole(s) of the two layers
  2. Rotate the hook by stretching the mesh
  3. And simultaneously entwining the mesh(es).
Please note-
  • if the chicken mesh is not stretched tightly then-
  • cracks might appear later while plastering the dome.
[[Image:]]

Show arrow on Chicken mesh at the nape of the frame

Remember to leave an extra 4-5 inch of chicken mesh at the nape of the frame.

Reason for this will be explained while fixing the dome on the digester tank.

[[Image:]] The entire frame should be covered with 3 bundles of chicken mesh.

This would form approximately 3 layers over the dome.

[[Image:]] The multiple layers of chicken mesh will help-
  • to hold the cement firmly while plastering the dome.
[[Image:]] Chicken mesh covering the entrance to the dome, should be cut with scissors.
[[Image:]] What you see here-
  • is the mason getting inside the dome through the same gap or the entrance.
[[Image:]] Once the chicken mesh is fixed-
  • remove the bamboo sticks placed inside for support.

Please note-

  • that the sticks have to be gently removed so as to not disturb the frame of the dome.
[[Image:]] Do so carefully and slowly.
Show a clock with animation of moving hands. The mesh dome is now ready and can be placed on the digester tank.


  1. Before shifting untie the 10 inch hammered steel rod from the base ring.
  1. And make sure of re-tying the loose ends of the mesh.
This brings us to the end of this tutorial of-
  • Constructing a dome for the Biogas plant.
Fixing of the dome on the Biogas plant will be explained in a later tutorial.
Slide 4

Summary:

We have learnt:

The step-by-step procedure to construct the dome of the Digester tank.

Let us summarize-

In this tutorial we learnt:

Step-by-step procedure to construct the dome of the Digester tank.

Slide 3

Acknowledgements

This video was created by:

Spoken Tutorial Project with inputs from Rural-ICT team, IIT Bombay.

This video was created by-

Spoken Tutorial Project with inputs from Rural-ICT team, IIT Bombay.

More information on these projects can be found at these links

http://spoken-tutorial.org/NMEICT-Intro

http://ruralict.cse.iitb.ac.in/ in

More information on these projects can be found at these links.

http://spoken-tutorial.org/NMEICT-Intro

http://ruralict.cse.iitb.ac.in/ in

Pictures and technology support:

Courtesy:

Bhagirath Rural Development Foundation

Village- Zarap, Taluka- Kudal,

Dist.- Sindhudurg

Pictures and technology support:

Courtesy:

Bhagirath Rural Development Foundation

Village- Zarap, Taluka- Kudal,

Dist.- Sindhudurg

This is Bella Tony along with the animation team of the Spoken Tutorial project signing off.

Thank you for joining.

Contributors and Content Editors

Bellatony911, Nancyvarkey