Cafe filter fabrication instructions

 

The Dryden Aqua DA Filter, is a low cost gravity flow filter, automatic back-washing without the use of any valves or control systems.  The filter is designed and intended to be constructed by Corporate Social Enterprise engineering companies located as close as possible to the place where the filters will be installed.  The engineering companies fabricate the filter for sale and distribution for rural community drinking water.

The Social Enterprise company should be in a position to provide technical support to the village to help them set up the system, and to be on call should they require any advice or support.  The village will be required to set up a committee with their own Social Enterprise organisation to maintain, manage and sell the water.  The sale from the water should cover the cost of maintaining the system with the support of the supplier.

The filtration system is suitable for any rural community from a village in Scotland to a remote community ion Africa. The design remit is based on providing clean water to a community that does not have access to clean water. The average income of the community is assumed to be in the region of 2 US dollars a day per working person.

Cost estimates.

Capital cost of all the equipment, including installation and commissioning, based on model 1200, supplying 1000 people with drinking water.

10 US dollars per person for Life, 30+ years,  1 to 2 x US dollars a year for power, maintenance and support

Dryden Aqua responsibility.

We are acutely aware if the issues regarding drinking water around the world, this was the reason for developing AFM as an active filter media, and was the reason for designing the rural community drinking water system.

Dryden Aqua will work directly with the filter manufacturing company and provide them with all the information required to construct the filters.  Dryden Aqua will also provide key components of the system such as the AFM.  There will be other components available from Dryden Aqua.  However, the manufacturer is free to locate their own suppliers or source of the key components.

If the equipment manufactured is in compliance with Dryden Aqua design specifications and uses grade 0 AFM, Dryden Aqua will certify the manufacturer and promote the company on a dedicated website.  The filter is designed to operate with AFM and it is only AFM that will deliver the full benefits.

 

Materials of construction

The main component of the DA Filter is the column comprising of the filter in the base and the water storage tank or top.  The unit may be constructed as one assembly of as two tanks with the water tank sitting on top of the filter tank.

It is important to sit the water tank on top of the filter, this prevents deflection of the top of the filter and allows the system to be constructed from lighter materials.

The materials of construction should be in compliance to you drinking water regulations, however in most countries the following would be acceptable

 

  • Stainless steel, the best but expensive, minimum 3mm
  • Mild steel, minimum 5mm thick and epoxy coated
  • Polyethylene or polypropylene, 12mm thick

The tanks are constructed in accordance the drawings.

 Nozzles.

The AFM filter media is supported by a Nozzle distribution plate, this plate is supported by pillars underneath the plate to prevent deflection.  Even although the system is low pressure, there are still large forces on the base plate.  The base plate should therefore be made of the following materials

 

Applies for filters up to 1200mm in diameter;

  • Stainless steel,  5mm thick
  • Mild steel 10mm
  • Polyethylene or polypropylene 24mm

For filters larger than 1200mm diameter, there is a different engineering solution for the nozzle distribution plate.

The number of nozzles used should be 60 per square meter of surface area supporting the AFM filter bed.  The nozzle should have 250 um slots.  If Nozzles are not available Dryden Aqua can supply this item.

Pipework

Pipework may be in PVC, ABS, Polyethylene or steel construction, the diameter of the pipework must be in accordance to the drawing.

 

Backwash water tanks.

The tank should be constructed into the the ground at the height shown in the drawing.  If the filter is elevated then the sump tank may remain in the ground, or it can also be elevated.  The back-wash flow rate will be dictated by the opposition of the the back wash tank.  The water flow for back-wash will need to be calibrated during the set-up procedure.

 

Model Number

DA.filter 300

DA.filter 600

DA.filter 1200

DA.filter 1800

DA.filter 2200

DA.filter 2400

DA.filter 3000

Filter diameter mm

300

600

1200

1800

2200

2400

3000

Filter height, m

4.5

4.5

4.5

4.5

4.5

4.5

4.5

Water flow rate, litres/hr

150

560

2250

5000

7500

10,000

15,000

AFM grade 0  mass in Kg

100

350

1400

3200

4750

5600

9000

Pump lift from surface, m

5

5

5

5

5

5

5

Flap valve dimension, DNmm

40

50

80

100

150

200

250

Pump power kw

0.05

0.1

0.15

0.3

0.5

0.75

1.1

 

Components provided by Dryden Aqua

In order for the equipment to be certified and for Dryden Aqua to provide support, it is essential that AFM is used in the system.  The manufacturers is free to use what every filter media they choose, but it is only AFM that will provide the material benefits and water security.

Dryden Aqua could supply the completed filter; this may be an option for the first few filters until the social enterprise engineering company is in a position to fabricate the complete system.  There may however be some difficulty in opting some of the item, such as the magnetic non return flap valve

Components from Dryden Aqua

 

 

 

 

 

AFM

 

 

 

 

 

Non return flap valve

 

 

Water pump, 12v dc brushless

 

 

Solar panel

 

 

Float switch interlock

 

 

Back-wash manual valve

 

 

 

 

 

 

 

 

 

 

 

 

                                    

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