Capstone Project
Department of Mechanical Engineering
Scope of Works
2012
Project Title:
Self Cleaning Downspout
Date:
11/03/2012
Project Team:
Identifier:
CP–[xxx]
Student workers:
Ravi Mehta, 359 681
Martyn Van Reyk
Mark Kortekaas
Benjamin To
Academic supervisor: Colin Burvill
Academic examiner:
Client Organisation:
[name]
Centre for Vocational Building Technology
Km Stone 147 Friendship Highway, Ban Thin, Group 5, Tambon Ban
That, 41150
+66 42248423
External Mentor:
Geoffrey Wheeler
CP–[xxx]
Version: [version number], [date]
1.
Project
Self-Cleaning Downspout
2.
Objectives
The main objective of the Self Cleaning Downspout Project is to design a mechanism that
will remove unwanted contaminants, primarily animal faeces, from the collected water. This
will be done by diverting the “first flush” of collected rainwater from the catchment area. The
system must fulfil the following requirements.
• Can be made from sheet metal of different
thicknesses using hand operated equipment.
• Economical
• Reliable, low maintenance
• Durable – 15 year life span
In reaching these objectives, we will have provided the following outputs to go with our
downspout model;fi first flush volume requirements
• Solid models and drawings in Inventor format
and on CVBT title block. PDF
• Down spouts (and gutters if needed) installed
and tested on 3 different roof sizes at Cal Poly.
• Fab’ instruction sheet tested at a Thai shop.
• Bill of materials compiled; Thai/English
• Processes & tooling spec’d in detail; T/E
• Sheet metal shops identified and evaluated
• Dissemination Materials Readys
o Fab’ instruction sheet published: T/E
o Logo or brand applied to spout
o Packaging/Display designed
o Ads published: print & web T/E
o Pricing issued T/E
3.
Definition of starting point
Despite the seeming abundance of water worldwide, a disproportionate rise in the
consumption of water per capita has resulted in the increased demand for freshwater supply.
In addition, the cost and energy required to process and deliver clean drinking water via
municipal systems is rising. With sixty eight percent of its population living in rural areas,
alternative cost-effective methods of water collection in Thailand need to be looked at.
Rainwater harvesting is one such method. While well and ground water is prone to be disease
infected, rainwater is relatively pure and safe to drink. It provides drinking water in areas that
may not be reached otherwise, and is generally easy to use. Despite this, it can be prone to
contamination from harmful particles on the roofs and gutters. To avoid this, the first thirty or
so litres (the ‘first flush’) of collected water need to be diverted. The general aim of the
project is to build a downspout system that diverts the contaminated ‘first flush’and can be
manufactured in rural areas.
Scope of Works 2012
page 2
CP–[xxx]
As rainfall is abundant, we are told water is not collected for the first two to four weeks and
can assumeany debris present will be washed off, leaving gutters clean. Hence, the primary
source of contamination is Enteric Pathogens such as bacteria, viruses and protozoa, present
in animal faeces or dead matter. While such contaminants may cause gastro-intestinal
infection, research from the WHO shows reported illnesses are rare. Despite this, it is still
advantageous to remove the floating matter and bacteria from collected rainwater to reduce
health risk as well as improve the aesthetic quality of the water. Dead animals and bacterial
growth cause an unpleasant sewage/rotten egg type smell.
Water quality testing is often divided into tests for either chemical or bacterial contaminants.
For general testing, bacterial contaminants are often tested. This is because chemical
contamination is often spread across a greater area and will therefore often be detected prior
to physical testing. Chemical contamination also rarely occurs without an expected pollutant.
Bacterial contamination is often tested by means of a presence/absence test because of
reduced costs. These P/A test are only capable of determining whether or not a specific type
of bacteria is present but cannot determine the concentration of these bacteria. A common
method of determining bacterial concentrations is the use of so called H2S strips. These strips
can determine the concentration of H2S, which is expelled by many bacteria. This test
however does not differentiate between harmful and non-harmful bacteria. The H2S method is
outlined by the WHO in 2002 and recommended by their guidelines for drinking water
quality from 2008.
To avoid the first flush, we aim to design a Self-Draining Downspout which automatically
diverts the initial contaminated water (exact volume to be determined). A team of two
students form PolyCal completed a fairly basic version of such a system, which diverted the
first 60 litres of collected water. The system had the following design features;
 Use of sheet metal galvanised steel, easy to fabricate in rural areas.
 Tube-design tank to hold 60 litres which attached to the gutter.
 Press fitted cap at bottom of tank to remove sediment once water is collected.
 Large inlet which made the downspout suitable for a variety of gutter sizes.
 Drain at bottom of tank allowed for automatic water removal.
Despite successfully meeting most of their design goals, the team identified various
improvements that could be made;
 Cost of system greatly exceeded the goal of 250 Baht. Cost may be reduced by; using
a cheaper grade of galvanized steel (no. 18 or 19), leaving more time for fabrication,
and using existing scrap pieces of flat metal sheets for fabrication
 The amount required to be diverted (60 litres) proved too conservative. Further
research may give us a better estimation.
 Press fitting cap at the bottom of spout (to be removed for cleaning) caused metal on
metal contact. Dirt captured between the cap and the tank made removal more
difficult, and a redesign of the bottom of the tank may be required.
In addition, we have identified the following improvements possible;
 System required villagers to place blocks underneath tank to raise it to correct height.
It may be possible to construct an easier and more stable method of adjusting tank size
 Absence of any filter of cap at top of trap tank allowed floating material at top of tank
to enter the collection stream once trap tank is full. A cap which rises with the tank
water level and blocks of the inlet once tank is full could solve this problem.
Scope of Works 2012
page 3
CP–[xxx]
4.
Task descriptions and Durations- Gantt Chart
Scope of Works 2012
page 4
CP–[xxx]
6.
End point
By the end of this project we will have developed an easy to use, durable and economical
downspout system which is can be installed on three different roof sizes in the village of
Nong Khai. We will have determined the amount of rainfall required in the ‘first flush’, tested
for harmful contaminants to be removed and designed hardware which removes unwanted
floating material from the collected water. Our system aims to be locally manufactured, with
a bill of materials and fabrication sheet suited to Thai manufacturing, as well as
Dissemination materials such as advertising and pricing available in Thai and English.
Sections 7 and 8 are only included for external projects, i.e. with an external collaborating
organisation.
]
7.
Mentor reviews
[
Identify critical stages in the project where an external mentor (if your project includes an
external collaborating organisation) must identify the preferred strategies or alternatives
presented by the student team.
This should be included in both written form, identifying critical task completion, and within
the first draft Gantt chart.
]
8.
Contractual agreement
We, the membership of student team CP–[xxx] agree to complete the tasks described in this
document.
If being formally completed for a Client Company (identified on the cover page of this Scope
of Works document) this document has incorporated all reasonable suggestions offered by the
Client Company mentor following that person’s review of an earlier draft of this Scope of
Works document.
SIGNED by the Student Researcher
SIGNED by the Student Researcher
Scope of Works 2012
)
)
)
)
)
)
)
)
)
)
)
)
..................................................
Student Researcher’s signature
..................................................
Student Researcher’s name (print)
..................................................
Student Researcher’s signature
page 5
CP–[xxx]
)
)
SIGNED by the Student Researcher
SIGNATURE OF Witness
(Academic supervisor)
Scope of Works 2012
)
)
)
)
)
)
)
)
)
)
)
)
)
)
..................................................
Student Researcher’s name (print)
..................................................
Student Researcher’s signature
..................................................
Student Researcher’s name (print)
..................................................
Academic supervisor’s signature
..................................................
Academic supervisor’s name (print)
page 6
CP–[xxx]
Scope of Works 2012
page 7