conductivity are often used as an easy way to automate blowdown. The "wet bulb temperature" is the lowest temperature to which water can be cooled by evaporation. Compared with the use and waste of city water the water consumption can be reduced with about 90 -. PHa is the actual pH of the water. Figure 1, relationship of temperatures related to cooling tower operation 10, range 7 Approach 95 F 85 F 78 F Hot Water Temperature To Cooling Tower (in) Cold Water TemperatureFrom Cooling Tower (out) Wet-Bulb Temperature Temperatures shownare illustrative only and subject to wide variation. Alkaline Treatment Programs There are several advantages to operating a cooling system in an alkaline pH range.0-9.2. Sometimes called "hyperbolic" towers due to the distinctive shape and function of their chimneys, natural draft towers do not require fans. Drift losses of up.2 of the recirculation rate in older towers can limit cycles to 5-10. When the fans stop, the performance of the tower will diminish significantly due to the lack of airflow. All corrosion inhibitor programs require a good biological control program and, in some cases, supplemental deposit control agents for specific foulants. Windage, drift, and leakage are all sources of unintentional cooling tower range thermal science paper tr-017
blowdown. Injection of carbon dioxide into the circulating water to control pH has been proposed occasionally. Heat rejection is primarily by evaporation of part of the cooling water. The wet bulb temperature is the temperature of the air if it were saturated with water (100 relative humidity). Those that monitor biological growth on actual or simulated system surfaces provide a good measure of system conditions. The tower pictured is a crossflow model. Elevated iron or copper levels in the circulating water can also be an indication of corrosion. In reality the cooling tower determines the difference between the cold water and entering wet bulb temperatures otherwise known as the approach. The fill section is the most important part of the tower. These towers can use either crossflow or counterflow air currents and tend to be larger than forced draft towers. The Ryznar Stability Index shows the same tendency when a value.0 or less is calculated. This program uses relatively high levels of orthophosphate to promote a protective oxide film on mild steel surfaces, providing superior corrosion inhibition. After that point, the hot and cold water temperatures rise at the same rate, but the range does not change.
The heat load absorbed by the water is given by the equation. Even if acid cannot be eliminated. Combinations of organic and inorganic phosphates are also used to inhibit corrosion at alkaline. Federal regulations limiting discharge of chromate to receiving streams sparked further efforts to reduce or eliminate chromate. T Where, extensive research to develop new, the tall up to 500 ft chimney is necessary to induce adequate airflow. Q m x c p x, environmentally friendl" heat absorbed from the process must be dissipated to allow reuse of the water. Early PhosphatePhosphonate Programs Many early corrosion treatment programs used polyphosphate at relatively high levels. Q heat load of process m mass ow of water c p specied heat of water constant. For a cooling tower based on evaporative cooling the maximum cooling tower efficiency is limited by the wet bulb temperature of the cooling air. T change in temperature of water range.
Cooling tower range thermal science paper tr-017
The form of calcium sulfate normally found in cooling systems. It was soon recognized that chromate. And evaporative condensers are used for this purpose. However, had certain health and environmental hazards associated with. Cannot always provide complete scale control.