Water distillation project
We have developed a scalable solution to clean water through distillation process using sun light and salt or dirty water. Our solution can produce 1 liter of water, per square meter of floating device per hour, 18 hours a day in hot climate conditions. This could save lives and produce enough drinkable water for local communities.
The initial prototype device is intended to prove the validity of the concept in terms of producing potable water from sea water.
The prototype will be designed in such a way that it can be modified in service to test a variety of alternative pumps and mechanisms. The purpose of the prototype, which is effectively a test rig, is to validate the efficiency of the design. The data obtained will be used as a foundation upon which the concept can be expanded to create firstly a tennis court sized unit but consideration will be given to much larger devices. Refinement and improvements in the operating efficiency of the device will be implemented during extended test programmes.
The plant consists of a number of individual stills that lock together with the floatation system to be designed to allow large surface to be covered and float in a sea or other water.
Each still consists of a clear top cover (currently shown in pyramid form), a base moulding and a novel wicking device which may be patentable.
The wicking device not only draws fresh seawater into the stills but also returns highly concentrated saline back to the sea.
The stills are supported by modular floats. These provide both flotation and the mechanical strength needed for a plant of this size.
The modular approach facilitates easy transportation and assembly.
A series of pipes connects all the stills together. Water will be delivered to land via a tough, industrial flexible pipe approximately 20mm ID
The plant will be built on dry land but could then be lifted into the sea and then floated into position.
If on the sea the plant may be tethered with anchors or lines to the shore.
We have sourced an off the shelf float that appears suitable for supporting the stills. Therefore no custom tooling is required for this part of the device. However tooling will be needed for the top cover and base units.
The custom tooling, top covers and base units would be sourced in the Far East under the control of our procurement manager who will regularly visit the site during product development.
The primary pump is expected to consist of two units that are solar powered. One is to act as a back up in case of mechanical failure or down time for routine maintenance. The pumps will be located either on or in the vicinity of the device.
We have a UK pump supplier involved in this area of the design who has worked with us on water orientated projects previously.
ASSUMPTIONS FOR PROTOTYPE PLANT
- The overall size of the device will be approximately 20 x 10 metres in plan view with an overall height of approximately 1.0 metre.
- Approximately 72 individual stills will be operated.
- Walkways to enable ease of access to the stills are to be provided
- To minimise the effect on the environment, the device will not be permanently installed.
- To minimise the cost of the prototype and energy consumption, human labour will be used to maintain the plant.
PRACTICAL TESTS AND MODIFICATIONS
There are many tests which we would be undertaken with the prototype. As lessons are learnt, the device would be modified and upgraded.
A few of the key areas that will be studied are as follows:-
1. Apply and test special coatings –
High thermal efficiency and easy cleaning are both essential prerequisites of this type of device.
It may be possible to improve the retention of solar radiation by applying special coatings to the Top Covers and therefore increase the temperature within the still.
Coatings may also be used to minimize the build up of residue both internally and externally. This will be beneficial in terms of maximizing performance whilst minimizing cleaning/maintenance effort and associated costs.
2. Variations in surface area and geometry of evaporation panels
Whilst most simple stills utilize a fixed reservoir of water this new design is intended to benefit from a continual wicking process where heat is applied over large areas of saturated material. To optimize efficiency of the wicking system experiments will be undertaken with sensors and automatic drive systems. We will start with the most basic (low cost) approach and move onto more advanced solutions.
Overall, this work is intended to maximize yield from a given physical size of still
3. Alternative cooling enhancement techniques.
Integral and remote cooling devices will be tested to optimize vapour condensation. These would involve both water and air based principles. We plan to use advanced computational fluid design software (CF Design CAD package) during the design process so we have an indication of the thermal issues that may affect the plant. The cooling effect of air currents will be analysed and maximized with the use of simple heatsink and aerofoil technology. The cooling effect of water whilst it flows and evaporates will be evaluated as ways of maximizing condensation.
4. Wick / Pump performance tests.
Whilst theoretically a wicking system is the most attractive option particularly in terms of cost and low energy requirements, we will also experiment with conventional (probably solar powered) pumps to replenish the reservoir tanks. These may prove more reliable and efficient overall.
5. Salt removal
As the seawater is distilled increasing amounts of salt will build up in the stills. We have a number of alternative ideas on returning the salt back to the sea which need to be investigated.
BUDGET COSTS AND TIMESCALES
We have undertaken a preliminary costing exercise with Far Eastern suppliers.
The following costs and timescales are subject to the engineering design that is produced.
Currently, all the materials and custom tooling are estimated at £20,000 plus VAT
The fees to design and engineer the prototype and larger test plant plus assembly and installation would also be approximately £10,000 + VAT.
Shipping and delivery costs are not included.
A project of this scale is expected to take 6-9 months to complete.
A photorealistic image of the device is shown below.
Start Date: 30 August 2016
End Date: 28 November 2016