Patent ID: 7638031

Claim:
A device for protecting an aqueous system from scale precipitation on contact-surfaces of the system, and for depressing scale precipitation in a bulk phase of a water supply, the device comprising: (a) an electrolytic cell for fluidly connecting to the aqueous system and for electrically connecting to a DC electrical power supply, said cell including: (i) a tank for receiving the water supply, said tank having a copper surface forming a cathode of said electrolytic cell; and (ii) at least one element having a zinc surface disposed within said tank, said element forming an anode of said electrolytic cell; (b) a controlling unit for controlling a current (I) from said power supply; and (c) a flowmeter for measuring a first flow rate of the water supply, said first flow rate associated with a total flow rate of water into the aqueous system, wherein said controlling unit is designed and configured to control said current according to said first flow rate so as to depress the scale precipitation in the bulk phase of the water supply, and wherein said current I exceeds a value of (1.84−A)*Q and said current I is less than a value of (1.84+A)*Q, wherein: I is said current, in amperes; Q is said total flow rate, in cubic meters per hour; and A is a positive number having a value less than 1.05.