EWB Group Project and Presentation

¶ … EWB Group Project and Presentation

Your team's task is to design and report on an efficient means by which the Kooma people of Bendee Downs can managing their available water resource in a sustainable manner. In particular, emphasis should be placed on a means of producing potable water from the available non-potable water sources such as salty bore water and gray water using solar distillation means.

In the interests of sustainability the solutions as far as possible should:

minimise raw material costs, use renewable energy (solar), utilise available on site resources and structures, have low maintenance requirements and a long service life, and be capable of being constructed by local labour.

The following processes need to be considered before a design is selected and developed and presented in your report:

a thorough research of the site and project requirements (from the EWB information supplied),

a literature review of the state of the 'Art'.

the production of a schematic diagram showing the types and availability of the water resources, the processes used for purification, the end uses for the purified water and the disposal of any waste products, the determination of the physics associated with the purification processes (energy inputs and outputs, evaporation and condensation, water and air flow).

Once the above parameters have been established a preliminary specification can be generated to control your preliminary design concepts. Your team should generate and consider three preliminary design concepts before choosing a final design for refinement.

Further details on the project and other resources will be supplied via the SAIBT Moodle Portal

Dear Students

I have extracted the relevant data for your project from the EWD PDF into word format. To the left is a plan layout of the proposed area under consideration. Note the available roof areas which may be relevant if your design is roof mounted rather than a stand alone system. Indeed if the roofs need to be replaced with new galvanized iron then this could result in considerable material savings for support structures and perhaps condensation units. I.e. part of the roof, say the side facing away from the sun could be used as a condensing surface. Unfortunately the map does not show the orientation of the buildings relative to North. Google Earth?

Below is the relevant text pertaining to this section. I have highlighted the relevant areas of concern.

You need to decide which source of water you are going to use. Apart from surface water the availability of which is irregular there are two sources of bore water.

One source is already potable (drinkable) comes out of the ground under pressure and is warm. However there ecological concerns associated with this water supply.

The other source is not potable (too much salt) and would need to be distilled. Furthermore it may need to be pumped to the surface.

You may need to find out what the water pressures and temperatures of both sources of water are for these artesian basins. This information should be available from government sourses. Google the names of the basins to find out.

The warm water under pressure could possibly be used for pumping the saline non-potable water to the solar still or through the solar still. In addition since this warm water is a source of energy it could also be used for preheating the water used in the solar still.

DESIGN AREAS TO BE CONSIDERED

The type of Solar Still, i.e. direct or indirect heating of water by solar energy.

The physics involved for circulating water and air.

Double or single glazing.

Trough type concentrators?

Special sunlight absorbing coatings. (may be too expensive to use)

Modular design, the dimensions, (determined by the size of available materials).

Materials for: the transparent cover, evaporator structures and surfaces, condenser structures and surfaces, supporting structures and plumbing.

Environmental deterioration of materials, i.e. By UV rays, heat, water, wind blown dust, corrosive salts.

Cleaning and maintenance considerations.

Distance of water supply from the Solar still.

Disposal or use of the concentrated saline water:

Used for flushing toilets? (May contaminate the septic system)

Can be used for growing food in special greenhouses that use salt water.

Excess salt could be sold?