Anemometer is a type of weather instrument which is used for measuring the wind speed.

The direction of the wind and its velocity that is measured by the anemometer helps the meteorologists in detecting the natural disasters caused by wind.
Anemometers measure several aspects of wind:

• Velocity
• Pressure

On the basis of these aspects, Anemometers are broadly divided into two categories:

• Pressure Anemometers
• Velocity Anemometers

As there is a close relation between these two aspects of wind (velocity and pressure), so either anemometer can give the adequate information about both.
Pressure Anemometers; are typically divided into two classes plate and tube anemometers.

Plate anemometers are constructed of a square or circular flat plate with a precision spring resting behind it. A wind vane keeps the plate directed against the wind, and the force of the plate against the spring can accurately measure the pressure of the wind. The majority of plate anemometers are not suited to record abrupt fluctuations in wind pressure, mainly because the fundamental design prohibits it. They are generally used to record average wind pressures.

Tube anemometers are of slightly more complex design than plate anemometers. These devices use a vessel with an opening at the top to record wind pressure. The pressure exerted through the mouth of the opening causes changes to the internal pressure of the chamber, which then allows calculations to be made concerning wind pressure. One advantage of tube anemometers is their self-sufficiency; they can be mounted atop a high pole and left unattended for long periods.

Velocity Anemometers; Velocity anemometers are divided into two classes: those that require some sort of wind vane and those that do not.

Cup anemometers are perhaps the most widely used anemometers. It contains four hemispherical cups that form a cross if viewed from above; the wind is captured in the cups, causing the anemometer to spin. A mechanism at the axis records and calculates the number of revolutions, which then allows wind velocity to be observed. Cup anemometers are simple and do not require intricacies such as a weather vane, but they do not record velocity at any given moment as accurately as other types do. For example, a sudden gust of wind may pass by unrecorded.

Windmill anemometers are based on the design of wind vanes, which simply illustrate wind direction. A windmill anemometer is more accurately described as an aero vane, which is essentially a wind vane with a propeller on it. The tailfin of the wind vane accurately displays wind direction, while the propeller at the front can record wind velocity by calculating revolutions per minute.

Other Types of velocity Anemometer are:

Hot-wire Anemometers; Hot wire anemometers use a very fine wire (on the order of several micrometres) electrically heated up to some temperature above the ambient. Air flowing past the wire has a cooling effect on the wire. As the electrical resistance of most metals is dependent upon the temperature of the metal (tungsten is a popular choice for hot-wires), a relationship can be obtained between the resistance of the wire and the flow speed. Hot-wire anemometers, while extremely delicate, have extremely high frequency-response and fine spatial resolution compared to other measurement methods, and as such are almost universally employed for the detailed study of turbulent flows, or any flow in which rapid velocity fluctuations are of interest.

Laser Doppler Anemometers; Laser Doppler anemometers use a beam of light from a laser that is divided into two beams, with one propagated out of the anemometer. particulates (or deliberately introduced seed material) flowing along with air molecules near where the beam exits reflect, or backscatter, the light back into a detector, where it is measured relative to the original laser beam. When the particles are in great motion, they produce a Doppler shift for measuring wind speed in the laser light, which is used to calculate the speed of the particles, and therefore the air around the anemometer.

Ping-pong ball Anemometers; A common anemometer for basic use is constructed from a ping-pong ball attached to a string. When the wind blows horizontally, it presses on and moves the ball; because ping-pong balls are very lightweight, they move easily in light winds. Measuring the angle between the string-ball apparatus and the line normal to the ground gives an estimate of the wind speed. This type of anemometer is mostly used for middle-school level instruction which most students make themselves.

Using Anemometers

i)  Measuring Variations in Wind Speed
Anemometers can be used to measure wind speed at various positions around buildings  (e.g. the school), over a transect, above different types of terrain and ground cover and at various points under variable meteorological conditions. Ideally, a number of anemometers should be employed for simultaneous measurements in different positions. Wind direction using a vane and compass should be recorded alongside wind speed.

ii) Measuring Vertical Changes in Wind Speed and Direction

Professional meteorologists can measure vertical changes in wind speed and direction using instruments bearing balloons which are released into the atmosphere. The various high profile attempts by balloonists in late 1996 and 1997 to fly around the world highlighted the vertical changes in weed speed and direction which the balloonists were attempting to exploit. Fieldworkers with their feet more firmly planted on the ground must be less ambitious but can, nevertheless, make some interesting investigations using one or more anemometers.

iii) Measuring Wind Speed Variations in Complex Terrains – Sand Dunes

Sand dune areas offer great opportunities for fieldwork using anemometers. Dunes develop as accumulations of wind blown sand grains up to 1mm in diameter. Of particular interest are the ways in which the geomorphology of the sand accumulation changes in response to variations in wind force and direction. Anemometers can be used to measure these variations and to assist in the measurement of sediment transport within dune areas.

Applications

• Anemometers are used for measurement of wind speed, wind velocity, wind pressure and wind direction and other information like the largest gust of wind during a particular amount of time. These instruments can be used in a backyard weather station or on a well-equipped scientific research vehicle.
• Industrial applications for anemometers include re-vegetation projects, projects taken on by NASA, research into shipboard wind speed, and measurements of the wind velocity on Venus.
• Sonic or ultrasonic anemometers, calibrated in a wind tunnel, and containing no moving parts, are really useful for measuring weather conditions that are very turbulent.
• Other applications are wind-tunnels and gas pipe technology.
•  It helps the meteorologists in detecting the natural disasters caused by wind.

Safety Guidelines

• Clean the cup regularly in case of cup anemometer. Heavy contamination in cup such as the bird droplets and ice can disrupt the accuracy of anemometer.
• Temperature range should not extend the operational range of the instrument.
• This instrument is NOT designed for gas mixtures other than air. Its use with corrosive or other dangerous gas mixtures can destroy the accuracy of instrument.
• High winds can be dangerous – be alert.
• Do not work close to cliff edges in windy weather.
• Beware of flying debris and falling objects in very windy weather.

Tweet

Air curtains are aerodynamically designed generating a laminar stream of air with sufficient quantity & speeds to offer the desired environment protection through open doorways or service hatches.

Air curtain acts as an invisible barrier isolating adjoining areas. Airflow may be horizontally across or vertically downwards. Air curtains help

• To prevent cold air from pushing its way in,
• To prevent warm air from disappearing out the door,
• Keep fresh air by preventing pollution, dust, insects
• Reduce the heating energy loss,
•  Cold draughts elimination.

The Air Curtain creates a uniform invisible barrier of high velocity air to divide different environments or clean, cool and/or dry various components or pieces. By utilizing the Coanda effect (wall attachment of high velocity fluid), air motion is created in its surroundings and ambient air is drawn in to produce a high velocity, high flow curtain of air for blowoff. This invisible “air-wall” is created that could also serve just as easily as a barrier preventing heated or conditioned air from leaving an area.

Air curtains consist of a fan and nozzle system which creates a jet of high-velocity air directed across a door opening, providing a protective air shield. The air shield minimizes the transfer of heat, moisture, dust, fumes and insects through the doorway. The Air Curtain fan adds kinetic energy to the air, providing resistance to the penetration of unwanted air or particles.

This added kinetic energy in the discharge air also resists the penetration of outside air due to wind, as well as the invasion of insects. The air is provided at a critical velocity and volume flow as well as a discharge angle selected for its particular application. The Air Curtain enables traffic to flow unobstructed through door openings while maintaining distinct environments, thus resulting in energy savings.

Advantages of Air Curtains

• Environmental separation for open doorways without the drawbacks of visibility-limiting solid barriers such as strip and impact doors;
•  Reduced risk of accidents as vehicles and people are able to move through doorways without obstructions to  visibility or movement;
• Provide excellent resistance to the penetration of outside winds;
• Prevent the intrusion of insects, fumes and dust;
• Reduce mechanical door maintenance costs;
• More aesthetically appealing than plastic strip doors or high-speed doors.

Applications

• Industrial climate control
• Industrial oven openings
• Dust and Humidity Control
•  Hard rock mines
•  At commercial entrances
• Pest Control
•  Cold storage
• Food product drying
• Can and Wine bottle drying
• Web cleaning and drying
• Environment separation

Pest/insects Control Air Curtains

Air curtain is a device that is used for cooling, drying and cleaning within various manufacturing lines and other processes. By using compressed air as their power source, a balanced sheet of airflow stretches across the full

length of the Air Curtain. The Air Curtain is used extensively in many industrial as well as commercial application areas to keep dust, contaminations or even flying insects/pests out by creating forceful turbulence.
Pest/insect control Air Curtains, sometimes called “Fly Fans” are used in

• Food processing plants
• Dairies and bakeries
• Bottling plants
• Restaurants and school cafeterias
• Supermarkets
• Hospitals and Pharma industries

And other areas where the control of flying insects is required. The powerful stream of air that is produced by Air Curtain/Fly Fan is an excellent deterrent to insects. Sanitation maintenance applications require these Air curtains/Fly fans that prevent airborne insects from entering. For fly and insect control, the Air curtain projects the high velocity air jets across the opening, deflecting and prohibiting the entrance on unsanitary insects, thereby maintaining sanitary conditions. The Air Curtain is equally effective either mounted horizontally or vertically.

For the pest/insect control the Air Curtains can be mounted on either inside or outside of the doorways. It is very important that the entire doorway be covered so that there are no gaps for the insects/pests to enter.

• Inside of the doorway; inside mounted unit helps to control the building’s climate in the winter by stopping the influx of cold outside air and preventing airborne insects.
• Outside of the doorway; when the building contains odors which are attractive to flying insects it is recommended that the Air curtain be mounted on the outside.

The most effective Air Curtain design for insect control has a nozzle that can angle the air stream away from the area to be protected. An angle of about 20 degree from the vertical is usually optimal.

For this application i.e. Pest/insect control which requires maximum protection, it is common and widely accepted to use a more powerful Air curtain in order to achieve the necessary level of protection.

Commercial Entrances; Air Curtains

Air Curtains; create an “invisible door” using laminar air flow, which effectively separates the outdoor and indoor air temperatures when the physical door is open.

Air Curtains are aerodynamically designed air blowers generating a laminar stream of air. These Air Curtains create an uniform invisible barrier of high velocity air to divide different environments. The Air Curtain is used extensively in many industrial as well as commercial application areas to keep dust, contaminations or even flying insects out by creating forceful turbulence. Some uses for Air Curtains are on customer entrances to keep the conditioned air inside the building from escaping.  This will increase customer comfort as well as energy savings. In industrial settings, Air Curtains are often used over dock doors. This helps reduce heating costs and increases employee comfort which in turn boosts productivity.

These Air Curtains are widely used for the entrances in commercial establishments such as stores, restaurants and banks and also ideal for public building entrances such as hospitals, terminals and school to reduce energy consumption and provide comfort. The working principle of commercial entrance Air Curtains is to provide the most effective air screen possible without blowing so hard that it is objectionable to people passing through.

In winter Air Curtain retains warm air inside and prevents the influx of cold air. They can also supply additional heat in the door area using optimal electrical, steam or hot water heaters. In the summer Air Curtains keep hot humid air out and prevent the escape or air conditioning.

Benefits while using air curtains at entrances

• Doors can remain open; air curtain creates an invisible door.
• Prevents heated or cooled air from escaping; Air Curtain separates two zones allowing different temperatures to be maintained.
• Reduces draughts and discomfort; increase comfort levels for staff, customers and visitors close to the doorways by reducing draughts.
• Energy saving; cost of running heating and air conditioned system can be reduced with Air Curtains as they help to seal the building from outside environment, making the building more energy efficient.
• Reduce ingress of insects and pollutants; insects, pollen and other air borne pollutants can be minimized by the Air Curtain.

Commercial entrance Air Curtains are normally mounted horizontally instead of vertically above the door that keeps the unit out of the way and practically eliminates any chance of damage/accidents. During the heating season, the air stream should be directed slightly toward the outside and should never be obstructed by door operators or the door header. It is recommended that the Air Curtain fan motor be run continuously, since the poser needed to operate it, is minimal.

Antique Furniture Protection; Air Curtain and Dehumidifiers 

It is important to cure and reserve our antique properties or furniture’s, it should be considered that antique furniture should not be cared or repaired in the same manner as modern home furnishing. There are many factors such as UV light, sunlight, hot air, relative humidity, moisture and insects/pests that affect the Antique Furniture.

Factors affecting the antique furniture/material

• Ultraviolet light; causes damages to antiques.
•  Sun light; can degrade early finishes, wood and fabrics for antique furniture.
• Relative Humidity; changes in the relative humidity can cause wood to expand and contract, it can cause glue joints to loosen, drawers and doors to drag or become stuck in their opening. And this extended period of high humidity can lead to mold growth, rot and insect infestation.
• Hot Air; heat can cause shrinking that can loosen glue joints, veneers, inlays and marquetry.
• Insects and Pests; wood, leather, fabrics and upholstery materials such as horsehair can be inviting to insects to insects and other small pests.

Air Curtains are aerodynamically designed air blowers generating a laminar stream of air. Air Curtain creates an uniform invisible barrier of high velocity air to divide different environments or clean, cool or dry various components.

The powerful stream of air that is produced by Air Curtain/Fly Fan is an excellent deterrent to insects. Sanitation maintenance applications require these Air curtains/Fly fans that prevent airborne insects from entering. For fly and insect control, the Air curtain projects the high velocity air jets across the opening, deflecting and prohibiting the entrance on unsanitary insects, thereby maintaining sanitary conditions.

Air curtains are the best device to control the indoor climate in all the places .These are used not only to prevent cold air from pushing its way in, but also prevent warm air from going outside the door.

Dehumidifiers are used to control the level of humidity in the antique furniture environment which is used for the storage and to prevent the growth of mold and fungus on the Antique furniture. Mold only requires a bit of moisture to grow, and it can set up shop at a place as soon as one of its airborne spores finds a hospitably damp surface. Dehumidifier also eliminates condensation and subsequent corrosion.

• Some other methods which are used for Antique Furniture care
• Avoid placing Antique Furniture in front of a window or direct sunlight.
• Avoid placing Antiques near air conditioning and heating vents.
• Do not place Antique Furniture near fireplaces and stoves.
• Blot up spills immediately.
• Dust regularly using a lint free cloth.

Air Curtain; Industrial Oven Opening

An Air Curtain is a continuous broad stream of air circulated across a doorway serving a conditioned space. Air curtains are normally mounted horizontally over the doorway. They can also be mounted vertically at the side of the door or under the floor directed upwards.

One of the most important benefits of Air Curtain is Energy saving

• Limits energy loss from conditioned space thereby reducing central plant capacity.
• Increases efficiency of cooling plant.
• Reduced carbon emissions.
• Reduces the running cost of a building.
• Recovers stratified air from high level.

Some of the major Applications of Air Curtain

Air conditioned areas; typical locations are at the entrances to retail stores to condition the ingress of outdoor air into the conditioned space.

Industrial climate control; Normal locations for Air Curtains are exterior doors to factories and warehouses as well as interior doors between factory areas of different temperatures.

Cold stores; used to reduce the loss of refrigerated air, minimize temperature variations and misting of a cold store each time the entrance is opened.

Clean rooms; Air curtains can be installed on the ‘clean’ side of a space to control the transfer of dust and humidity through the doorway.

Other uses; Air curtains are also used for diverse applications such as in the mining industry, insect control in food  processing plants, dairies, restaurants, supermarkets and across the openings of industrial ovens and refrigerated display cabinets. They may also be used to separate smoking from non-smoking areas, helping to maintain an agreeable internal environment.

Industrial Oven Opening

It is very important to save energy and fuel during the performance of an Oven. Using Air Curtains on opening to ovens has resulted in fuel savings of up to 40% of the total oven fuel consumption.
These Air Curtains are normally installed horizontally over the oven opening and angled slightly inward toward the oven to contain the hot air that is trying to come out at the top.

Many Air Curtains are successfully operating on ovens with temperatures up to 475° F. The Air Curtain drive motor should be located to the side of the oven opening to protect them from damage from hot air that would escape in the shutdown of the Air Curtain. Oven applications should be designed case by case to meet each set of unique condition.

Tweet

An Air Curtain is a continuous broad stream of air circulated across a doorway serving a conditioned space. Air curtains are normally mounted horizontally over the doorway. They can also be mounted vertically at the side of the door or under the floor directed upwards.
One of the most important benefits of Air Curtain is Energy saving

• Limits energy loss from conditioned space thereby reducing central plant capacity.
• Increases efficiency of cooling plant.
• Reduced carbon emissions.
• Reduces the running cost of a building.
• Recovers stratified air from high level.

Some of the major Applications of Air Curtain are
Air conditioned areas; typical locations are at the entrances to retail stores to condition the ingress of outdoor air into the conditioned space.
Industrial climate control; Normal locations for Air Curtains are exterior doors to factories and warehouses as well as interior doors between factory areas of different temperatures.
Cold stores; used to reduce the loss of refrigerated air, minimize temperature variations and misting of a cold store each time the entrance is opened.
Clean rooms; Air curtains can be installed on the ‘clean’ side of a space to control the transfer of dust and humidity through the doorway.
Other uses; Air curtains are also used for diverse applications such as in the mining industry, insect control in food processing plants, dairies, restaurants, supermarkets and across the openings of industrial ovens and refrigerated display cabinets. They may also be used to separate smoking from non-smoking areas, helping to maintain an agreeable internal environment.

Industrial Oven Opening
It is very important to save energy and fuel during the performance of an Oven. Using Air Curtains on opening to ovens has resulted in fuel savings of up to 40% of the total oven fuel consumption.

These Air Curtains are normally installed horizontally over the oven opening and angled slightly inward toward the oven to contain the hot air that is trying to come out at the top.

Many Air Curtains are successfully operating on ovens with temperatures up to 475° F. The Air Curtain drive motor should be located to the side of the oven opening to protect them from damage from hot air that would escape in the shutdown of the Air Curtain. Oven applications should be designed case by case to meet each set of unique conditions

Tweet