Cooling tower nozzle نازل کولینگ تاور
Cooling tower nozzle
The cooling tower nozzle creates a turbulent flow that causes the tower to spray water, and therefore this shower is sometimes called a spray. In simpler terms, the main center of the water spray and distribution system in the cooling tower is called the nozzle. The nozzles can be used in a Constant Water Distribution system called Spray Nozzle or in a Rotary Water Distribution system in which case it is called Water. They are called sprinklers .
Nozzle = center and heart of hot water spray and distribution system in cooling tower
How does a cooling tower nozzle work?
The fluid in the fluid knowledge, by increasing the speed and pressure, causes the hot water flow of the tower inlet to be sprayed and spread on the cooling surfaces. The ratio of velocity and pressure change at the outlet and inlet of the fluid flow depends on the ratio of the inlet to outlet cross-sectional area. According to the Bernoulli relation in fluids, as the output cross section decreases, the pressure and consequently the linear velocity of the water flow also increases. Increasing the linear velocity of the water droplet outflow will increase the kinetic energy of the water flow and thus spray and distribute the water flow on the heat exchange surfaces.
What is a cooling tower nozzle?
The sprayer's function in the cooling tower is to distribute hot water flow under a certain radius on the packing media. After spraying water, this fluid is in contact with the induced air created by the cooling tower fan . The distribution of water in the showers is done by a special mechanism by creating turbulence in the water flow. In many types of cooling tower nozzles, this turbulence is caused by impeller-shaped parts (rotors). Reducing the cross section and creating turbulence in the water flow causes the water flow to be disrupted and the so-called outlet droplets are sprayed. For this reason, this model of sprayers is also called the spray nozzle of the cooling tower (Spray Nozzle).
Hot water is directed to the water distribution system by inlet flanges. The fixed water separator system includes nozzles, belt clamps, O-ring washers, caps, crepes and branch pipes. Depending on the type of cooling tower (cubic or conical) water distributor can be designed as a square or circular sprinkler. Also, in order for the nozzle to function properly, care must be taken that the inlet pressure of the water flow to the cooling tower is within its standard range. The following figure shows how the water distribution system is branched by the square nozzle of the cooling tower .
History of cooling tower nozzle
Afshanak Kooling Tower has undergone many changes in design, size and material over time. The first generation of this spraying equipment with a simple cross-sectional mechanism was responsible for distributing the water flow. This model is used today under the name of Orifis or Staircase. There is practically no turbulence in the internal mechanism of the horn for the wide distribution of water at the outlet in this generation of cooling tower nozzles. The first examples of this model, called sprinklers, such as shower showers with low spray radius and high pressure, were responsible for distributing water in concrete and wooden cooling towers.
Due to poor performance, high-pressure cooling tower nozzles were replaced by low-pressure, high-spray models. The first examples of this equipment were generally produced and supplied from metal materials such as cast iron and brass. Over time, with the development of the petrochemical and plastic injection industry of Dama Gostar Company , produce and supply cooling tower nozzles from polymeric materials. The main and important advantages of polymer or plastic sprays over metal types were their lightness, non-reactivity with water and less sedimentation. In fact, polymer water distribution systems are the latest generation of water spray showers in the cooling tower. The material of this type of cooling tower nozzles is PP or ABS material.
How the cooling tower nozzle works
The flow of hot water entering the cooling tower from the inlet flange enters the water distribution and spraying system. This part includes pipes that spray hot water in different parts. The cooling tower nozzle is located in different parts of the branch pipes and is installed at regular intervals. The incoming water flow from the outlet of a certain number of nozzles starts spraying on the cooling or packing media surfaces. This spraying of water in a certain radius by a certain number of nozzles completely covers the surface of the packings and as a result the water in the tower cools down.
The best performance of a cooling tower nozzle occurs when the surfaces of the pads or cellulose pads are completely covered by the water flow. The process of completely wetting the packings in the cooling tower is also called overlap. The better the spray performance, the better the overlap. Proper operation of the water distribution system results in less free space (Void Space). Cooling tower nozzle efficiency is basically the ratio of the pressure difference (outlet-inlet) to the inlet pressure of the showers. As the spraying efficiency increases, the spray of water flow at the output of this industrial shower model will be more efficient.
Cooling tower nozzle design
In order to design a nozzle in a cooling system, it is necessary to observe a few basic points. The first parameter in the design of the cooling tower nozzle is the spray radius. In order to achieve the required radius of spray in the design of water distribution system, it is necessary to observe two basic points. The first point is the working pressure to achieve the desired water distribution radius in the design and the second point is the nozzle outlet distance to the cooling surfaces. By observing the standard distance of the nozzle from the heat exchange or packing surfaces and also providing the required standard working pressure, the fixed showers of the cooling tower will reach the spray radius considered in the design.
The second parameter in the design of the nozzle or water spray pipe is the ratio of the change in the output cross section to the inlet cross section. This cross-sectional change ratio in the cooling tower nozzle is actually the most important design parameter. Nozzle cross section ratio is done by ANSYS and FLOWENT engineering software.
More information in the design and calculations of the cooling tower
How to produce a cooling tower nozzle
The production of this part of the water distribution system in the cooling tower is done in two common ways. 1- Plastic injection method 2- Turning method. In a closer look, it should be noted that in fixed water spraying systems, nozzles are produced from 1/2 size to 3 inch size. It is produced from PP-ABS-PVC polymer material by plastic injection method. In order to produce fixed showers, first the design of this equipment is done by SolidWorks 3D software. Afshanak 3D programming design becomes a machining template. The mold is placed inside the plastic injection machine according to the three-dimensional design of the cooling tower nozzle.
After injecting the raw materials of granules or polypropylene R60, R220 and HDPE polyethylene inside the funnel of the plastic injection machine and after the thermal processes inside the plastic injection machine, the material is injected from inside the funnel to the primary mold part and after cooling the mold part, The nozzle exits the mold. In the second method, which is mostly used to produce a rotating cooling tower nozzle. The complete plan of the sprinkler or water dispenser is finalized by the lathe operator after the casting operation. The second method of mold production nozzle is used to produce water dispenser or sprinkler cooling tower (with metal material).
How to install a cooling tower nozzle
In order to install the nozzle in the water spray system of the cooling tower, it must be noted that the type of water spray system is fixed or rotating. If the water spray system is a rotary cooling tower (conical cooling tower), a rotating nozzle or impeller is used as a water dispenser or sprinkler head. The choice of sprinkler size depends on the size of the inlet and outlet and the flow of circulating water. Usually the working pressure of the cooling tower water dispenser (sprinkler) is between 2 to 2.5 bar. The sprinkler is usually placed directly on the inlet pipe and is connected by an automatic screw or thread. Special adhesives are used to seal the sprinkler or water dispenser and the inlet pipe of the cooling tower.
Sprinkler outlet pipes are usually between 4 and 6 pieces. These pipes are perforated before installation and have a cap. After connecting the sprinkler outlet pipes, the water is drained from the outlet holes of the pipe by rotating this equipment on the cooling surfaces. Observing the distances and diameters of the holes in the sprinkler outlet pipes or water dispensers is one of the important principles of installing this water circulation equipment in the cooling tower. If the water spray system in the cooling tower is of a fixed type, a series of belt clamps and sometimes a core are used to connect the cooling tower nozzle to the cooling tower inlet pipes. In order to completely seal the nozzle, it is recommended to fasten the belt or nut and use Teflon tape and o-ring (plastic washer).
What is the meaning of the spray radius and working pressure of the cooling tower nozzle?
Spray radius: The meaning of the nozzle spray radius in the cooling tower is the same as the surface of the outlet cover of this water spray shower. In engineering terms, the amount of surface that the nozzle sprays water is called the nozzle radius. For example, a sprayer nozzle in a cooling tower with a spraying radius of 50 cm covers a circle with a diameter of 50 cm. In fact, the spray radius is the same as the amount of water overlap at the nozzle outlet on the cooling surfaces. The radius of the water spray in the nozzle or shower spray is directly related to the diameter of the nozzle outlet. The larger the diameter of the nozzle outlet, the higher the surface area of the cooling tower nozzle.
Standard pressure: The nozzle working pressure is basically the standard pressure required for correct spraying. In fact, the nozzle working pressure causes a proper distribution of water flow. The working pressure of the cooling tower nozzle is directly related to the spray radius and the nozzle distance from the packing media surface. The working pressure is in fact the minimum necessary pressure of the cooling tower nozzle for proper spraying and distribution of water. Working pressure generally varies depending on whether it is fixed or rotating between 0.7 bar and 3 bar. In some cases, the inlet pressure of the cooling tower spray nozzles is also determined by the PSI unit.
Technical specifications of cooling tower nozzles
The nozzle, like many internal components of a fiberglass cooling tower, has basic characteristics that fall into different categories based on these characteristics. The parameters that differentiate this equipment are:
- Spray radius
- Working pressure
- How to spray water
- Input size
- Output size
- Material
In the table below, you can see the technical specifications of the types of cubic and conical cooling tower nozzles.
Types of cooling tower nozzles
- Cooling tower nozzle nozzle
Sprinkler is a term used to describe a spray nozzle with a small spray radius and a powdery water distribution. In other words, the mister simply blows the incoming water from the cooling tower into the air in the form of mist. The function of the sprayer is to increase the relative humidity in the air. The sprayer is typically used in cooling towers or evaporative condensers. The mist is also used in various types of air washers to increase the relative humidity of the environment.
- Cooling tower drip nozzle
A model of spray showers that sprays a certain percentage of water flow in the form of droplets of water on the cooling surfaces of a cooling tower. Cooling Tower Dropper Nozzle generally has a spray radius of 20 to 60 cm. Types of spray nozzles include screw, left, solar and lantern nozzles.
- Cooling tower spray nozzle
Another type of spray that sprays and distributes a high percentage of water flow is called the Cooling Tower Spray Nozzle. Sprayers mainly have a spray radius of 60 to 120 cm. Sprayers are generally more efficient than the spray and spray models. Cooling tower spray nozzles include square spray (spray deck), 2H model and Baltimore model.
Types of cooling tower nozzles in terms of working pressure
- Low pressure: working pressure less than 1.2 bar
- Under pressure: working pressure between 1.2 bar to 3 bar
Types of cooling tower nozzles in terms of type of function
- Fixed water spray nozzle
- Rotary or rotary spray nozzle
Types of cooling tower nozzles in terms of type of water spray
- Cooling Tower Square Sprinkler Sprinkler
- Cooling Tower Circular Sprinkler Sprinkler
Cooling tower nozzle price
The nozzle price varies depending on the type, shape, input and output size and material (amount of material used). As it is clear, one of the main items influencing the price of cooling tower nozzles is the type of this equipment. The price of spraying showers for rotating cooling towers is mainly higher than the types of fixed systems. The reason for the higher price of the rotary water dispenser compared to other nozzles of the cooling tower is in its material material. The price of rotating nozzles in three modes of brass, aluminum and cast iron is very different. The price of polymer nozzles is much lower than metal types. The lowest price in the nozzle belongs to PP and ABS models in the cooling tower.
The exact price of a square spray nozzle or spray deck is determined depending on the type of material used. The highest price of water showers belongs to brass water dispenser or sprinkler. The price of brass water dispenser is actually higher than the price of fixed nozzle types. The nozzle price of a rotary cooling tower varies depending on the size of the water dispenser. As the size of the spray increases, its price will also increase depending on the material used in the production of this part. In order to check the exact price of the cooling tower nozzle, it is recommended to first select the type, size and material of this equipment according to the technical specifications of the technical catalog. After selecting this equipment, contact the experts of the sales department of Damagostar company.
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