What is draft fan?
Forced Draft Fan is a type of a fan supplying pressurized air to a system. This fan supplies air to the Air-Preheater, where it captures the heat from the flue gases coming from the Boiler Outlet.
What is the ID fan?
Induced draft fans or ID fans are used in systems such as steam boilers and thermal oil heaters to draw out and remove flue gases from combustion chambers, by creating a vacuum of negative air pressure (typically -10 mm Hg).
How does a forced draft fan work?
Forced draft (FD) is achieved by forcing air into a furnace with a special fan and ductwork. Often, air is heated prior to entering a boiler to increase overall efficiency. FD boilers usually operate with a positive pressure. Traditionally, dampers have been used to control the quantity of air admitted to a boiler.
What is the difference between forced draft fan and induced draft fan?
Induced draft implies an inlet fan placed on top of the cooling tower and the creation of low pressure. Forced draft means an exhaust fan placed at the base of the cooling tower which then causes overpressure. …
What is an induced draft fan?
An induced draught fan (ID fan) is provided to maintain a negative pressure in the furnace by sucking the products of combustion from it with a slight positive pressure at the discharge end vis-à-vis the bottom of the chimney/stack.
Why induced Draught is better than forced Draught?
The air is sucked in the system by reducing the pressure through the system below atmosphere. The induced draught fan sucks the burned gases from the furnace and the pressure inside the furnace is reduced below atmosphere and induces the atmospheric air to flow through the furnace.
What is a forced draft system?
Forced draft: When air or flue gases are maintained above atmospheric pressure. Normally it is done with the help of a forced draft fan. Induced draft: When air or flue gases flow under the effect of a gradually decreasing pressure below atmospheric pressure. Draft is said to be zero in this system.
What is a forced draft burner?
Webster’s FDR(X) Forced Draft Register burner is a highly efficient combustion system for power plants that combines a windbox, air register, ignition assembly, fuel train, flame safety control, combustion control, FGR (Flue Gas Recirculation) system, and a forced draft blower, all assembled into one complete packaged …
How does the flow of air occur in natural Draught cooling towers?
Explanation: In natural draught cooling tower, the flow of air occurs due to the natural pressure head caused by density difference between the cold outside air and hot humid air inside. This increases the cooling rate by increasing the air velocity over the wet surfaces and through the tower.
What is the disadvantage of natural Draught?
Explanation: The only disadvantage of natural draught is that the available draught decreases with increasing the outside temperature. Explanation: The natural draught in the steam generator depends upon the air condition outside chimney & the temperature of the exhaust gases.
How is draft created?
Since hot combustion gases weigh less per volume than room air or outdoor air, they tend to rise. The rising is contained and increased by enclosing the gases in a tall chimney. The vacuum is then created throughout this column of hot gases. Chimney height — the higher the chimney, the greater the draft.
What is wet cooling tower?
Wet Cooling Towers are those buildings where the water that was heated by industrial or power generation processes is cooled, again. The heat is given off to the environment. Wet cooling towers are an integral part of the thermodynamic circle. The water to be cooled is sprayed and distributed over the splash fills.
What is meant by wet bulb temperature?
The Wet Bulb temperature is the temperature of adiabatic saturation. This is the temperature indicated by a moistened thermometer bulb exposed to the air flow. Wet Bulb temperature can be measured by using a thermometer with the bulb wrapped in wet muslin.
What is the working principle of cooling tower?
Air enters the tower beneath the fill and is drawn up vertically into the tower. Above the fill, hot water is introduced through low pressure spray nozzles to divide the hot water over the surface of the fill in fine droplets. The cooling air draws heat from the water as it progresses to the bottom of the tower.
What is a purpose of cooling tower?
Cooling towers are primarily used for heating, ventilation, and air conditioning (HVAC) and industrial purposes. Cooling towers provide a cost-effective and energy efficient operation of systems in need of cooling. More than 1,500 industrial facilities use large quantities of water to cool their plants 2.
Are cooling towers dangerous?
Cooling towers can be breeding grounds for potentially deadly Legionella bacteria without proper cleaning and maintenance. Dirty cooling towers can be deadly. In July, an outbreak of Legionnaires’ disease in New York sickened 27 people and led to one death.
How much do cooling towers cost?
On average, cooling towers cost about $125,000 to replace. In the United States, a cooling tower replacement will typically cost between $50,000 and $200,000 for the year 2019. A commercial cooling tower will last between 15 and 20 years according to most manufacturers of commercial cooling towers.
How often should a cooling tower be cleaned?
twice a year
How long does a cooling tower last?
20 years
How much does the chiller cost?
A survey of the major manufacturers shows an average cost for the chiller itself of approximately $350 to $1,000 per ton, depending on capacity (see Table 2).
Do chillers use refrigerant?
Process chillers contain a chemical compound, called a refrigerant. An air-cooled condenser uses ambient air to cool and condense the hot refrigerant gas back down to a liquid. It can be located inside the chiller or can be remotely located outside, but ultimately it rejects the heat from the chiller to the air.
How many types of chillers are there?
three different types
What is difference between air-cooled and water cooled chiller?
An air-cooled chiller has a condenser that is cooled by the environment air. The water-cooled chillers have water cooled condenser connected with cooling tower and are usually preferred for medium and large installations where there is sufficiency of water.