Water Reticulation System Group D.docx 535e1w

ABSTRACT

In the process of deg a water reticulation system. A research was conducted to find out the technical and practical aspects of such an undertaking. Based on this research, calculations were done to determine the various parameters that would make this a pragmatic design. The size of the tank, the types of pipes, height of the tank stand, the flow rate and velocity were determined. The tank size was double the daily water consumption requirements of the community for contingency purposes. The pipe size from the pump to the tank was selected based on the diameter of the pump’s outlet. The size of the pipe from the outlet of the tank was chosen based on its advantages in of velocity. The size of the pipes connecting the tank’s outlet pipe to the households were chosen based on research.

Table of Contents ABSTRACT ......................................................................................................................................................................1 1.0.Introduction .............................................................................................................................................................3 2.0 BACKGROUND THEORY ............................................................................................................................................4 2.1 FLOW RATE ..........................................................................................................................................................4 2.2 DERIVATION OF FLOW RATE ................................................................................................................................4 3.0 DESIGN AND PROCEDURE ........................................................................................................................................6 3.1 POPULATION ........................................................................................................................................................6 TABLE 3.1.2. ESTIMATED PRESENT WATER NEEDS ................................................................................................6 3.2 STORAGE TANK ....................................................................................................................................................7 3.3 PIPE SIZE...............................................................................................................................................................7 3.3.1 𝟏𝟏𝟒 Inch ..........................................................................................................................................................8 3.3.2 1inch .................................................................................................................................................................8 3.3.3 2inch ................................................................................................................. Error! Bookmark not defined. 3.4 Calculations showing the flow rate and speed from the outlets of the tank and 1inch pipe. .............................9 4.0 CONCLUSION .........................................................................................................................................................10 5.0 REFERENCES ...........................................................................................................................................................11

1.0.Introduction

A water reticulation system is in basic how water is distributed at various point in a network .This distribution is made possible by use of pipes, tanks and boreholes. For this system to function a good design is of the essence. The primary aim of this project is to design a water reticulation system that will supply a community of ten (10) households with an average of four (4) people per house. This project focuses on the design of the water reticulation system. Objectives Determine the amount of water required by an individual per day. Determine the amount of water required by a single household per day. Determine the amount of water required by the community. Determine the size of the tank required by the community. Determine the sizes of the pipes to be used at various point in the system. To show the engineering drawing of the designs. Our problem was solve by determining an appropriate design of the system, the right size of the tank and the sizes of pipes to be used at various points. In our case we chose a 5000Litres 1 tank, a. 1 4 inch from the pump to the storage tank, a 2inch pipe for the main supply pipe and 1inch pipes from the main supply to each household.

2.0 BACKGROUND THEORY

In our design of the water reticulation system, it was cardinal to determine the mass flow rate. This was imperative in determining the velocity of the water in the household supplying pipes.

2.1 FLOW RATE Flow rate refers to the measure of the volume of the liquid per unit of time. It is dependent on the area of the path that the liquid is flowing through and the velocity of the liquid through it.

2.2 DERIVATION OF FLOW RATE Consider an incompressible fluid (e.g. water) flowing through a pipe as shown in figure 2.1

Its volume is given by: 𝑉 =𝐴×𝐿

eq.2.1

Therefore the volume ing through the pipe is given by 𝑉

𝑄 = 𝑇 = (𝐴 × 𝑙)/𝑡

eq.2.2

But the velocity (v) is given by distance peer unit time I.e. 𝑣 = 𝑙/𝑡 Therefore we can substitute eq.2.3 into eq.2.2 thus

eq.2.3

𝑄 = 𝑣𝐴

Eq.2.4

Eq.2.4 is what is known as the flow equation Now consider pipes of different areas A1 and A2 as shown I fig 2.2

The volumetric flow rate must be the same for both pipes. Because we cannot gain or lose any fluid thus Eq.2.4

𝑄 = 𝑉1 𝐴1 = 𝑉2 𝐴2

eq2.5

This is referred to as the continuity equation and is true for any changes in pipe diameter for a single flow path

3.0 DESIGN AND PROCEDURE

3.1 POPULATION POPULATION OF THE COMMUNITY

= NUMBER OF PEOPLE PER HOUSEHOLD * NUMBER OF HOUSES =4 × 10 =40 PEOPLE

TABLE 3.1.2. ESTIMATED PRESENT WATER NEEDS

POPULATION OF THE COMMUNTITY

UNIT USE(LITRES)

TOTAL(water consumed per day)

40

60

2400

The tank size was doubled taking into various water usages stated below;    

Irrigation Losses such as leakages Water for domestic usage Water for domestic animals 𝑇𝐴𝑁𝐾 𝑆𝐼𝑍𝐸 = 2 × 𝑇𝑂𝑇𝐴𝐿 𝑊𝐴𝑇𝐸𝑅 𝐶𝑂𝑁𝑆𝑈𝑀𝐸𝐷 𝑃𝐸𝑅 𝐷𝐴𝑌 = 2 × 2400 = 4800L

3.2 STORAGE TANK The standard tank size for the design chosen was 5000L. This tank is made up of polyethylene. The reason the tank design was made of this material was because this was the most recommended material for the storage of drinking water. The figure below shows an example of the ideal tank chosen for the design

3.3 PIPE SIZE Having conducted a research, pipe size from the pump to tank was selected on the basis of the pump used. For this design the pump selected was DSP 1-10 as in appendix B. DSP 1-10 has an outlet diameter 1 of 1 4inch which requires that the pipe attached should be of the same diameter. Based on the same research, the recommended outlet pipe from the storage tank was 2inch and the pipe size branching from the main supply to each house-hold is 1 inch All pipes used in this design are Poly Vinyl Chloride (PVC) which have now become a replacement for metal piping. The following advantages where the key factors in helping make this selection. These include; 

Corrosion resistant ;corrosion is one of the most harmful and threatening issues, especially in water pipes, as it threatens our ability to get safe and pure drinking water.



Light weight; the low weight facilitates easy and effortless installation without the risk of getting injured or needing a large workforce.



Cost ; PVC pipes are much cheaper than steel pipes

𝟏

3.3.1 𝟏 Inch PIPE 𝟒

This was the pipe chosen from the borehole to the inlet of the tank.

3.3.2 1inch PIPE This pipe was used from the main supply to each household

3.3.3 2inch PIPE This is the main supply pipe from the outlet of the tank

3.4 Calculations showing the flow rate and speed from the outlets of the tank and 1inch pipe. 𝑄 = 𝑉1 𝐴1 =(1.4 × 𝜋 × 50.82 × 10−6)/4 =2.48 × 10−3 𝑚3 /𝑠

Where v1 is the velocity of the water from the outlet of the tank in the 2inch diameter pipe and A1 is the cross section area of the 2inch dimeter pipe CLACULATONS FOR THE VELOCITY OF WATER IN THE 1INCH PIPE: Where v2 is the velocity of water in the 1inch diameter pipe and A2 is the cross area of the 1inch pipe. 𝑄 = 𝑉2 𝐴2 𝑉2 = 𝑄/𝐴2 = (2.84 × 10−3 × 4)/(𝜋 × 25.82 × 10−6 ) 5.43𝑚/𝑠

4.0 CONCLUSION

The water reticulation system design was finalized. This was achieved through the subsequent completion of each objective. This included determining the amount of water required by the community, the tank size, and the pipe sizes finally the drafting of a suitable engineering drawing using Computer Aided Design Software. By and large, the project was a success. Further alterations and upgrades to this project will include an electrical system which will be the main concern of future projects relating to this one.

5.0 REFERENCES

UNTITLED AUTHOR https://www.itacanet.org/fluid-mechanics-for-gravity-flow-water-systems-and-pumps/part-3derivation-of-the-continuity-equation-3/