What is the difference between natural draft and mechanical draft

What is the difference between natural draft and mechanical draft cooling towers?

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. … We also supply spare parts for this cooling tower type.

How does a mechanical cooling tower work?

Mechanical draft Uses power-driven fan motors to force or draw air through the tower. Induced draft A mechanical draft tower with a fan at the discharge (at the top) which pulls air up through the tower. The fan induces hot moist air out the discharge.

What are the three 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 are the advantages of forced draft cooling tower?

Comparison Between Forced Draft And Induced Draft Cooling Tower

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Advantages Disadvantages
Induced draft Axial fan
Low absorbed capacity little space required Higher noise level Humid air stream drive
Forced draft Axial fan
Low absorbed capacity Easy maintenance Dry air stream drive Higher noise level

How do you calculate TR on a cooling tower?

Multiply 500 times the water flow rate, times the temperature difference, divided by 12,000 or 500 x q x dt/12,000. The result is the tons of capacity of the cooling tower.

What is natural draft cooling tower?

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. … The warmer, moister air moves to the top of the tower, while the cold water is collected at the bottom.

Is a cooling tower a condenser?

Cooling towers and condensers both heat exchanger equipment but operate in opposite ways. Condensers turn a substance from gas to liquid by way of cooling it (with either air or water that would come from a cooling tower).

What is the process of cooling tower?

Cooling tower systems work by using water to extract waste heat from a system and ejecting it into the atmosphere primarily through evaporation. … The water is then distributed over the top of the cooling tower where air travels past the warm water causing a portion of the water to evaporate.

Which type of cooling tower is more efficient?

Counterflow (induced draft) systems are considered the most efficient of the two. Crossflow (forced draft) towers distribute hot water perpendicularly to the air flow, while counterflow towers distribute hot water directly into the air flow.

What are examples of cooling systems?

Types of Cooling Systems

  • Central Air Conditioners and Heat Pumps. Central air conditioners and heat pumps are designed to cool the entire house. …
  • Room Air Conditioners. …
  • Evaporative Coolers. …
  • Ductless Mini-Split Air Conditioners. …
  • State of the Art Cooling.

What is the application 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.

What are the two types of cooling systems?

There are two types of cooling systems: (i) Air cooling system and (ii) Water-cooling system. In this type of cooling system, the heat, which is conducted to the outer parts of the engine, is radiated and conducted away by the stream of air, which is obtained from the atmosphere.

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What is a cooling tower wet deck?

What is a Cooling tower fill material? Fill, or wet deck or surface, is a medium used in cooling towers to increase the surface area of the tower. This enlarged surface area allows for utmost contact between the air and the water flow, which as a result allowing greater evaporation rates.

How is the performance of the cooling tower indicated?

How is the performance of the cooling tower indicated? Explanation: Approach can be defined as the temperature difference between water leaving the cooling tower and ambient wet-bulb temperature. If the approach is low, then the performance is good and vice-versa.

What is a cross flow cooling tower?

In a crossflow tower, air travels horizontally across the direction of the falling water whereas in a counterflow tower air travels in the opposite direction (counter) to the direction of the falling water. … This is because of the air inlets on each style of tower.

How do you calculate the volume of a cooling tower?

Estimate the system volume by measuring the sump of the tower and the water level in it. Multiply the number of cubic feet of water by 7.5 to get the number of gallons. Then add 10-20% additional water for piping, etc.

What is TR cooling capacity?

Ton of Refrigeration (TR): Ton of Refrigeration (abbreviated as TR) is an important historical unit of refrigeration capacity. Originally 1 TR was defined as the rate of heat transfer required to make 1 short ton (2000 lbs) of ice per day from water at 0oC.

What is cooling capacity of cooling tower?

The Figure 7.2 illustrates various cooling tower types. Mechanical draft towers are avail- able in a large range of capacities. Normal capacities range from approximately 10 tons, 2.5 m3/hr flow to several thousand tons and m3/hr.

Why do cooling towers have hyperbolic shapes?

First and foremost, the hyperboloid shape impacts the strength of the entire structure. Since cooling towers are supposed to cool the working fluid down to a low temperature, they release vapors into the atmosphere through the opening at the top of the tower. … This is why cooling towers have a large, circular base.

What is the working principle of a natural draft cooling tower?

Cooling towers use the principle of evaporation of water against the air flow. Hot water is sprayed from the nozzles for increasing the heat transfer surface area. The temperature and humidity of the air get increased after direct contact heat transfer between hot water and fresh air.

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What two types of fan are used for cooling towers?

Mechanical Draft towers tend to use a fan to force the air. Propeller or centrifugal fans are used to circulate air inside the tower. These are much smaller in structure than natural draft towers. Capacity control is easy in these types of towers since the speed of the fan can be controlled.

What is the difference between an air cooled condenser and a cooling tower?

The difference is that the water-cooled chillers or rather the cooling towers use a humid air stream (ambient air stream + water spray) while the air-cooled chillers use a current of ambient air. Normally water-cooled chillers are cheaper and more efficient, with the disadvantage of high water consumption.

Do cooling tower fans work?

Tall, compact tower fans can significantly cool down your rooms when temps soar. … When the temperature rises, an air conditioner, ceiling fan or other cooling devices can only do so much. A tower fan can bring down a room’s temperature without cluttering up your space and is easy to store when not in use.

What is use of cooling tower Mcq?

Cooling tower is used to cool the hot water coming from condenser. This water is cooled by evaporating cooling by the flowing air.

What industries use cooling towers?

The primary industries that use cooling towers include petroleum refineries, chemical manufacturing plants, primary metals processing plants, glass manufacturing plants, rubber products manufacturing plants, tobacco products manufacturing plants, and textile manufacturing plants.

What is difference between cooling tower and chiller?

Mechanical draft cooling towers rely on fans to pull cool air into the system to remove the heat from water. … Chillers utilize compressors, evaporator heat exchangers and condenser heat exchangers. The condenser heat exchanger is the major component that rejects heat from the chillers to air.

What causes a cooling tower to overflow?

Overflow: If the water level in the basin gets too high, it will flow through here and out to a drain. Drain: Water will be drained from the cooling tower for maintenance purposes but also periodically during normal operation when the level of impurities in the water gets too high.