By AZoM.com Staff Writers
Cockpit Breathing Air
Dry Air Supplies on Ships
Missile Launch Systems
Moisture Measurement Solutions from Michell Instruments
About Michell Instruments
Since many military applications need dry air supplies, modern armed forces could be described as operating on compressed air. This article covers a few key applications of compressed air and the moisture controls required to maintain the supply dry.
Pressurised cylinders are used to store breathing air for pilots. It is essential to keep the high pressure air dry, in order to avoid freezing of the components and supply pipes during air expansion.
The dew point of the air supply can be measured by a Michell Instruments Easidew Portable or MDM300 before use to verify that the air satisfies the correct specifications for dryness, as part of the routine maintenance schedule.
Most modern naval (and commercial) seagoing vessels employ compressed air for several applications – from running machines and tools for maintenance to performing aerobic breakdown of sewage and starting and controlling the engines.
Since seawater is used for cooling the air compressors on the ship, efficient drying is especially crucial. High pressure air (typically 3000 to 5000 psig) needs to be dry to avoid freeze-up of components and valves when the air expands, while low pressure air is dried to avoid component damage and condensation.
Launching of all submarine-launched ballistic missiles is performed using compressed air to allow the firing of the missile from under the sea. Prior to the launch, the missile tube is pressurised to equal the water pressure outside, followed by the opening of the hard hatches to leave just a thin diaphragm between the water and the missile.
For launching the missile, the diaphragm is removed by means of an explosive charge, and the missile is drawn out of the tube at speed with the high-pressure air. After reaching the surface, the engines are ignited and the missile is set to its target.
Although the release of the compressed air takes place in underwater, starting with a dry supply of air is critical to prevent ice forming and damaging delicate parts during rapid decompression when the missile launches.
Continuous monitoring of the compressed air dryer provides complete peace of mind. A dew-point transmitter with a monitor like the Easidew Online will deliver online measurements with a local display.
A dew-point sampling system provides the same continuous measurements with display in addition to sample filtration, and pressure and flow controls for easier installation.
The Michell ES10 is a sampling system with two alarms that can be set to send an alert when the dew-point is not within in the defined range.
As part of routine maintenance, portable hygrometers can be used for online measurements and spot checks at points of use. Portable hygrometers help engineers to determine leaks or faults within the system far away from the dryer. Michell Instruments offers two portable dew point hygrometers for making spot checks of compressed air systems.
The MDM300 from Michell Instruments is a high-speed portable hygrometer that enables repeatedly fast measurements within 15 minutes, thereby optimizing productivity during the day. It is lightweight, small and designed to be operated while being held even with gloves on. The battery is operable for 48 hours on a full charge.
The Easidew Portable is a powerful hygrometer capable of operating in hostile environments, and provides low cost of ownership owing to low maintenance. It is convenient to operate and is equipped with an integral sampling system to perform reliable measurements each time.
Manufacturers of dew-point transmitters, dewpointmeters, chilled/cooled mirror hygrometers, relative humidity sensors, process moisture analyzers, hydrocarbon dew-point analyzers, moisture in liquid analyzers and oxygen analyzers, Michell Instruments is an international leader in high-precision sensing with over 30 years’ experience in the field.
Our range of high-precision capacitive moisture sensors help customers to measure trace moisture in their process applications, whilst our relative humidity transmitters and relative humidity and temperature sensors are widely used in HVAC applications, pharmaceutical storage and other production processes where controlled environmental conditions are crucial.
This information has been sourced, reviewed and adapted from materials provided by Michell Instruments.
For more information on this source, please visit Michell Instruments.
Originally posted 2013-12-12 03:09:16.
Article source: http://www.azom.com/article.aspx?ArticleID=10426