Aerotech Energy Pvt Ltd

Mira Road (East), Thane, Maharashtra

OverviewAir cooled steam condenser is required to condense the exhaust steam from the turbine into the condenser at constant pressure and temperature and required to maintain the backpressure at   the turbine exhaust flange.

What is a Air cooled steam condenser?Air cooled steam condenser comprises of Tube Bundles with Circular/Flat / Elliptical  finned tubes fixed at a height on a “A”  or V- frame structure at an angle of 60 Deg. Axial Flow fan mounted at the lower vertex of the ‘A’ or ‘V’ Frame throw the cooler air at ambient temperature into the ‘A’ or ‘V’ Frame. When the Air passes through the finned tube bundles it will cool the fluid inside the finned tubes or condenses the steam inside the tube by reducing the latent heat of steam.


Components of Air cooled steam condenserAir cooled condenser comprises Cells / modules / bays. Each cell consists of the following major equipment:

• Steam Manifold / Steam Duct from Turbine exhaust flange to the ACC.
• A Frame structure supporting the Tube Bundles
• Axial Flow fan arrangement with Gear Box and Motor.
• Condensate & Hotwell Tank with Pumps
• Ejector for extraction of the Non condensable gases from the tube bundles.
• Piping with valves and instruments as per the requirement.
• Instrumentation and Electrical as per the ACC operational philosophy.

Single Row Tube Bundles generally are generally arrangements of flat fin tubes having Single Row in Tube Bundles. Since these tube bundles have single row that’s why they are called as Single Row Fin Tube Bundles.

As compared to the multi-row arrangement single row heat exchangers have the following advantages:

• Optimal Resistance against freezing
• Less weight
• Higher Heat Transfer area

OverviewThe high cost of power has made manufacturers look into equipment to reduce power consumption. Cooling Towers, heat exchanger, humidification and ventilator are areas where a major saving is possible at reasonable cost for manufacturers.

What is FRP Fans?Aerotech’s aerodynamically designed energy efficient FRP Hollow axial flow fans have helped in 20% reduction in power consumption and recovering the cost of fan in short time.
Traditionally Cast aluminum fans consume more power due to low efficiency and heavy weight. The fans operate throughout 24 hours using excess power, which can be saved by using  Aerotech’s energy efficient FRP Hollow bladed fans.
Aerotech has designed and developed structurally strong FRP hollow fans which are light-in-weight with help of USA based NACA* computerized software, having more lift and low drag airfoil shape, Engineered twist, optimized chamber to increase the fan efficiency resulting a nominal low operating cost.

Components of FRP FansAerotech method of Axial Flow Fan design is based on data obtained from the combination of the blade element theory, model fan tests in a wind tunnel, and tests of full scale fans in the field. The data are plotted as curves for fans of standard theory form, making the actual operation in designing the fan very short and simple. For the analysis or design of special blade which is not conforming to the standards, the modified blade element theory is used, with airfoil section characteristics, which give resultant powers and efficiencies checking the standard model data.

 APPLICATION OF AXIAL FLOW FANSThe axial flow fans are widely used for providing the required airflow for the heat & mass transfer operations in various industrial equipment and processes. These includes cooling tower for air conditioning & ventilation, humidifiers in textile mills, air–heat exchangers for various chemical processes, ventilation & exhaust as in mining industry etc. All major industries use large number of axial flow fans operation, such as :

• Cooling Towers
• Heat Exchangers
• Humidifiers
• Ventilation
• Industrial Air Circulator
• Man Cooler
• All type of Industrial Axial Flow Fan

Products

• Energy efficient FRP Axial Flow Hollow fan Assemblies
• Aluminum Axial Flow Hollow fan Assemblies
• FRP fan Stack
• FRP Inlet Bell Mouth For ACC
• Drive Shaft
• Gear Box

Range of FRP Axial Flow Fans:

• Fan diameter : 250mm to 15000mm
• Air Flow : 0.5 M3/s to 2500m3/s
• Pressure : 1mm to 100mm
• Tip speed Limit : Up to 70 M/s

Range of Aluminum Axial Flow Fans :

• Fan diameter : 250mm to 5500mm
• Air Flow : 0.5 M3/s to 400m3/s
• Pressure : 1mm to 100mm
• Tip speed Limit : Up to 100 M/s

Feature of Aerotech FRP Fans:

Corrosion Free Material: The raw material i.e. Fiber Reinforced Plastics (FRP) provides the desired non-corrosive quality to the fan blades, resulting in the operation of the fans even in the chemical environment.

Lightweight: FRP is Lightweight material which ensures a low moment of inertia, minimum wear & tears on motor, bearing and drive system. Hollow FRP blades is lighter than aluminum fan assembly which makes it easy to carry and due to light weight there is no possibility of damage to fan & drive during sudden stops.
Tailor Made Designs: Composite structural design can be tailor made by using various glass fibers (Glass cloth & woven roving mat and roving) in right direction while moulding the fan blades with Epoxy resin thus imparting the desired mechanical strength by improving its industrial stability and enhanced mechanical properties.
Aerotech design of the fan blades ensure more airflow, lower noise level & less power consumption means high efficiency. The AERODYNAMICALLY designed fan impeller of the fans, fabricated by composite material can be excellent alternative to ensure enhanced efficiency & appropriate energy saving apart from wide gamut of critical advantages.

USP of Aerotech FRP Fans:

HOLLOW FAN BLADES.The hollow design of fan blades The basic purpose of a “fan” is to move a mass of gas or vapor at the desired velocity. For achieving this objective there is a slight increase in the gas pressure across the fan rotor or impeller. However main aim remains to move air or gas without any appreciable increase in its pressure. The total pressure developed by the fan is of the order of a few millimeter of water gauge. A “blower” which is also referred to as “fan” in some literature deliver the gas or air with the appreciable race in pressure to overcome some kind of resistance in the flow. Some applications develop pressure of the order or 1000 mm W.G. or more. An axial flow fan stage in its simplest form consists of a rotor made up of number of blades fitted to the hub. When it is rotated by an electric motor or any other drive, a flow is established through the rotor. The actions of the rotor causes an increase in the stagnation pressure of air or gas across it. A cylindrical casing encloses the rotor.

AERODYNAMIC DESIGN OF FRP HOLLOW BLADEAs mentioned previously the choice of correct twist and of special airfoil sections to reduce compressibility losses are of major importance in modern fan blades design. However other considerations still remain to be studied with care if the efficiency of the blade is to be kept at its maximum under severe operating conditions.

CENTRIFUGAL AND AERODYNAMIC TWISTINGIn variable-pitch fan as described later the blades are turned in the hub about their longitudinal or pitch-change axis. Clearly the mechanism provided to produce this pitch change must be capable of exerting sufficient force to overcome any mechanical or aerodynamic opposing force set up by the blades themselves. It will be useful then to see exactly what these force are.
The “mechanical force” involved is known as Centrifugal Twisting Moment (C.T.M)which as its name implies is closely allied to the normal centrifugal force acting on the blades when the fan is rotating about the shaft . It is turning couple brought about by the fact that the blade section are inclined at an angle to the fan of rotation and results in the natural tendency for any fan blade, when rotating turned about its longitudinal axis towards zero pitch so that the blades section are turned in to the fan blade rotation .

THRUST AND TORQUE FORCES.The main factor that determines the force developed by an aerofoil section is the angle at which it is inclined to the relative airflow, i.e. the angle of attack in order, therefore, for the fan blade section to develop the requisite aerodynamic force for propulsion, each section along the blade must be inclined at the appropriate angle of attack to the relative airflow direction pertaining to the section hence knowing angle of attack is a simple mater to indicate the force developed as shown in figure 1) from which it will be noted that the total blade angle of attack and the helix angle.

The medium to be cooled is allowed to flow through tubes. Water is sprayed over tubes to form a water film surface; cool air is blown over the tube surface with help of induced draft fans mounted at the top.

Temperature of both cool air and sprayed water rises, partial water will transform from liquid phase to vapor. Latent heat of vaporization water will carried out massive heat. While, a negative pressure will be formed inside the heat exchanging tube cabinet under the effect of fan’s induced draft, which will enhance the evaporation of sprayed water, thus increasing heat transfer efficiency. Non-vaporized water will be cooled down during falling into the circulation water tank. The water inlet valve will automatically refill cooling water to keep a certain water level and a normal circulating operation. While the medium to be cooled remains in a closed circulation.

Manufacturer of ACC, CT, ACHE, Evaporative Condenser, Adiabatic Cooling Tower, FRP Energy Saving Fans

Axial Flow (propeller type) fans are used in towers. Generally, propeller fans are used in induced draft towers, fans are found in forced draft towers. Depending upon their size, the type of propeller fans used is either fixed or variable pitch. A fan with non-automatic adjustable pitch blades can be used over a wide kW range because the fan can be adjusted to deliver the desired air flow at the lowest power consumption.