Abstract: Disclosed is a method and apparatus for preventing or minimizing scale deposition from hard water onto heat transfer surfaces in atmospheric cooling towers, such as those used in air conditioning and refrigeration systems, where evaporative cooling of water provides the necessary heat sink to the atmosphere. An electrical/mechanical control system responsive to changes in density of the water in the evaporative cooling system operates to permit discharge of water containing dissolved and suspended solids from the system when its density reaches a predetermined maximum value and to discontinue the discharge of cooling system water when its density reaches a predetermined minimum value. Water drained from the cooling system is replaced by fresh water, preferably by water containing chemical additives to increase solubility of hard water minerals in the cooling water.

Abstract: Disclosed is a method and apparatus for preventing or minimizing scale deposition from hard water onto heat transfer surfaces in atmospheric cooling towers, such as those used in air conditioning and refrigeration systems, where evaporative cooling of water provides the necessary heat sink to the atmosphere. An electrical/mechanical control system responsive to changes in density of the water in the evaporative cooling system operates to permit discharge of water containing dissolved and suspended solids from the system when its density reaches a predetermined maximum value and to discontinue the discharge of cooling system water when its density reaches a predetermined minimum value. Water drained from the cooling system is replaced by fresh water, preferably by water containing chemical additives to increase solubility of hard water minerals in the cooling water.

Abstract: Disclosed is a method and apparatus for preventing or minimizing scale deposition from hard water onto heat transfer surfaces in atmospheric cooling towers, such as those used in air conditioning and refrigeration systems, where evaporative cooling of water provides the necessary heat sink to the atmosphere. An electrical/mechanical control system responsive to changes in density of the water in the evaporative cooling system operates to permit discharge of water containing dissolved and suspended solids from the system when its density reaches a predetermined maximum value and to discontinue the discharge of cooling system water when its density reaches a predetermined minimum value. Water drained from the cooling system is replaced by fresh water, preferably by water containing chemical additives to increase solubility of hard water minerals in the cooling water.