Dr Denzil Rodrigues

2. Dr Denzil Rodrigues Technical Manager, Hydropath Holdings Ltd.

3. Electronics

4. Electronics • The Hydropath signal is a decaying sine oscillation • Around 120 kHz • (2000 times faster than mains!) • Pulse separation time varies to work in a range of situations • Extremely low power • (Less than 20W) Electric current travels along whole pipe

5. Electronics • How do we get a signal into the pipe? • Transformer • AC current in primary circuit • Magnetic field through ferrite • AC current in secondary circuit • Make secondary single loop • Make loop bigger... Patented

6. Electronics • Alignment of pipe • Position of pipe through unit • Topology (knot theory)

7. Electronics = =

8. Electronics

9. Electronics: Comparison with Magnetic Wirewrap (electromagnet) Magnet • Magnetic fields (not Electric Fields) • Very weak ( E = c B ) • Depends on flow rate (no flow, no protection) • Local (point protection only)

10. Electronics • Signal Propagates over long distances • AC signal allows current to flow in “open circuit” • Faraday cage effect does not apply

11. Limescale

12. Limescale • Calcium and bicarbonate dissolved in water • Water becomes super-saturated when: Temperature increases or pressure decreases • Ions precipitate as calcium carbonate: limescale Ca Calcium (HCO3)2 Bicarbonate CaCO3 Calcium Carbonate CO2 Carbon Dioxide H2O H2O Water

13. Limescale

14. Seed Crystals • Crystals need a start point to form (a nucleation site) • Crystals prefer to form on existing crystals • No existing crystal: crystals form all along string • Existing crystal: will grow rather than form new crystals

15. Prevention of scale Without Hydropath With Hydropath

16. Dissolving existing scale • Crystals form • Creates Carbon Dioxide • Dissolves existing scale H2O Ca + (HCO3)2 CaCO3 + CO2 + H2O • To dissolve scale, Hydropath requires Hard Water Feed

17. Dissolving existing scale After Before

18. Dissolving existing scale Plate exchanger After one month Before Before – AFTER CLEANING! After eight months

19. Flocculation

20. Flocculation • Filters can only remove “big” particles • Particles penetrate into filter material and cause clogging • Stick particles together “flocculate” • Enhance filtration • Reduce backwashing by a factor of five With Hydropath Without Hydropath

21. Flocculation Hydropath unit Filter Pump Particles become charged Turbulence mixes up particles; flock formed Filter removes flock

22. Bacteria and Algae

23. Osmosis and Bacteria • Semi-permeable membrane: passes water, but not salt. • Water flows from dilute to concentrated region H2O H2O Na Cl Na Cl Cl Na Semi-permeable membrane

24. Osmosis and Bacteria • Semi-permeable membrane: passes water, but not salt. • Water flows from dilute to concentrated region • Bacteria cell: semi-permeable membrane • In distilled water, water flows into bacteria • Bacteria becomes “too dilute”, dies, bursts • (kills even “freshwater” bacteria) H2O H2O H2O H2O H2O H2O Cl Cl Na H2O H2O H2O H2O Na H2O Cl Cl Cl Cl Na Na Na Na Na H2O Na Cl Na Cl Cl Cl Na Semi-permeable membrane

25. Hydropath and Bacteria • Consider bacteria in salt water • Hydropath charges bacteria, creating a wetting layer • Layer of very pure water around bacteria • Osmosis forces water into bacteria • Bacteria dies Cl Cl Cl Cl Cl Cl Cl Cl Cl Cl Na Na Na Na Cl Cl Cl Na Cl Na Na Na Na Na Na Na Na Cl Na Cl Na Cl Na Na Cl Cl Na Cl Cl Cl Cl Cl

26. Hydropath and Bacteria

27. Cooling Towers Pressure decrease • Limescale • Flocculation • Bacteria and Algae Heat increase

28. Cooling Towers • Black = cold • White = hot • Hot coffee on edge of mug

29. Side-stream Filtering • Side stream filter removes and returns water to same place • Some of the water has already been filtered • Need to pass about 10 times the total volume through filter before all water is filtered

30. Summary • Electronics • Limescale • Flocculation • Bacteria and Algae