What are natural draft cooling towers?
What are natural draft cooling towers?
The natural draft cooling tower is an open, direct-contact system. It works using a heat exchanger, allowing hot water from the system to be cooled through direct contact with fresh air. To increase the heat transfer surface area (and optimize the cooling process), hot water is sprayed from nozzles within the tower.
What are the different types of cooling towers?
There are three main types of cooling towers that are defined by how water or air pass through them. These types include crossflow, counterflow, and hyperbolic. There are also two varieties classified solely on airflow, known as induced draft and passive draft cooling towers.
What is the most common type of cooling tower?
Mechanicaldraft cooling towers
Mechanicaldraft cooling towers are the most widely used in buildings and rely on power-driven fans to draw or force the air through the tower. They are normally located outside the building. The two most common types of mechanical draft towers to the HVAC industry are induced draft and forced draft.
Which type of cooling tower is best?
One particularly effective type of natural draft cooling tower is the hyperbolic cooling tower. These cooling towers use a chimney-stacking design to let the dry, cool outside air push the warm, moist air. The bottom of the tower contains splash fill, and the cool air moving upward cools the water spraying over it.
What is natural draft?
Natural draft: When air or flue gases flow due to the difference in density of the hot flue gases and cooler ambient gases. The difference in density creates a pressure differential that moves the hotter flue gases into the cooler surroundings.
What is the difference between natural draft and mechanical draft cooling towers?
Natural draft cooling towers allow for air circulation through natural convection, pushing hot air out and cool air in. Mechanical draft cooling towers, on the other hand, functions in a similar way but deploys fans and other equipment to circulate air.
What is forced draft cooling tower?
The forced draft cooling towers remove low-potential heat generated in the production process. They use atmospheric cooling with wet technology and forced draft. A counterflow of air and hot water in the cooling fill results in a heat transfer.
What is the difference between natural and forced draft cooling tower?
Natural draft towers rely on a “chimney effect” to obtain circulation of the air through the water. Mechanical draft towers use fans to move the air and are subdivided into forced-draft or induced draft towers.
What is the difference between forced draft and induced draft cooling tower?
Induced draft implies an inlet fan placed on top of the cooling tower and the creation of low pressure. Axial fans are always used for this type of draft. Forced draft means an exhaust fan placed at the base of the cooling tower which then causes overpressure. Both axial and centrifugal fans can be used.
What is natural Draught and mechanical Draught?
Natural draft cooling towers make use of the chimney operation of the cooling tower. The air flow is caused by the temperature difference between the air inside and outside the cooling tower. The fans used in mechanical draft cooling towers cause the air flow.