Glossary of Power Engineering Terms
All
| Term | Definition |
|---|---|
| ABSOLUTE HUMIDITY |
The amount of moisture present in the air, measured in kg / kg of dry air. |
| ABSOLUTE PRESSURE |
The pressure of a fluid measured relative to a complete vacuum. It is gauge pressure plus the pressure of the atmosphere. |
| ABSOLUTE ZERO |
The zero point on the absolute temperature scale; 0 Kelvin. Minus 273.16 degrees on the Celsius scale. |
| ABSORBENT |
A substance which is capable of extracting one or more constituents from a mixture of gases and or liquids, and which undergoes a physical or chemical change while performing the extraction. |
| ABSORBER |
The area of the low side of an absorption system used for absorbing vapour refrigerant. |
| ABSORPTION |
The process by which atoms, molecules or ions in a gas or liquid are brought into a solid or liquid. Absorption differs from Adsorption in that the atoms, molecules or ions are taken up by the internal volume of the solid or liquid, rather than remaining on the surface. Absorption often involves a chemical reaction and is not as readily reversible as Adsorption. |
| ABSORPTION REFRIGERATION |
The process where exhaust steam and a pump is used in place of the refrigeration compressor. |
| ABSORPTION TOWER |
The tower (contact tower) that uses amine to absorb sour gases in a gas sweetening process. |
| ACCUMULATOR |
A type of safety device, located between the evaporator and the compressor, used to reduce the liquid refrigerant carryover flow to the compressor suction. |
| ACETONE |
A colourless, volatile, inflammable liquid (CH3COCH3). |
| ACETYLENE |
A colourless gas (C2H2) prepared by the action of water with calcium carbide. Acetylene is used in gas welding and cutting. |
| ACID |
A covalent substance that, when dissolved in water, produces hydrogen ions (H+) in the solution. A substance capable of donating a proton (+) to another substance. The strength of an acid is determined by its pH value. |
| ACID (SULPHITE) PROCESS |
A chemical pulping process that uses a chemical calcium sulphide (acid) solution and heat to break the bond between the cellulose and wood fibres. |
| ACID GAS |
A sour gas composed of hydrogen sulphide, H2S. |
| ACID PROCESS |
A process used in the making of steel using an acid type slag. |
| ACIDITY |
In water: the excess of hydrogen ions (H+) over hydroxide ions (OH-) that occurs where the pH is less than 7. |
| ACTIVATED ALUMINA |
A form of aluminium oxide that absorbs moisture readily and is used as a drying agent. |
| ACTUAL AIR (FREE AIR) DELIVERED |
The quantity of air delivered, expressed in cubic meter per minute at the conditions of temperature and pressure existing at the inlet to the compressor. |
| ACUTE ANGLE |
An angle that is greater than 0 degrees but less than 90 degrees. |
| ADJACENT ANGLES |
Angles that share a common vertex and a common line. |
| ADSORBENT |
A substance containing enormous internal surface area that is capable of extracting one or more constituents from a mixture of gases or liquids by the physical attraction of the extracted material to the above mentioned surface area. No physical or chemical change of the adsorbent results. |
| ADSORPTION |
The binding of atoms, molecules or ions to the surface of a liquid or solid. This is different than Absorption which is bringing the atoms, molecules or ions inside the solid or liquid . The binding to the surface is usually weak and reversible. |
| AFC |
Alberta Fire Code. |
| AFTER COOLERS |
Devices that remove the heat of compression of air or other vapour after the last compression stage. |
| AGGLOMERATION |
The growing or coming together of small, scattered particles into larger flocs, or particles, which settle rapidly. Refer to Floc. |
| AIR COOLED CONDENSER |
A condenser cooled by the natural or forced circulation of air through or over it. |
| AIR DIFFUSER |
A device, usually at the ceiling, used for the distribution of the conditioned air from the terminal of the air duct(s). |
| AIR GAP |
In an electrical machine, the space between the rotor and stator across which magnetic lines of flux must travel through air. |
| AIR PREHEATER |
A heat exchanger that supplies heated air for combustion. Heat is transferred from the hot flue gases to the combustion air. |
| AIR TO FUEL RATIO |
Amount of air used compared to the amount of fuel supplied to the burner over the entire range of fire. |