Useful Terminology Flashcards
Flocculant
refers to the chemical or substance added to a suspension to accelerate the rate of flocculation or to strengthen the flocs formed during flocculation.
Fire Point
The temperature at which an oil produces enough vapor to support continuous combustion.
Flash Point
The temperature in which a flammable liquid produces enough vapor to allow ignition momentarily.
Soapstone
A soft slippery metamorphic rock that is used as a lubricant or lubricant additive.
Photocell
A device that generates an electric current when exposed to light.
Soil
Human waste from toilets
Vacuum Breaker
Prevents water or fluids from being back siphoned.
Waste
Liquid waste from faucets or sinks or any liquid waste
Waste Stack
A vertical pipe used in a building to move soil and waste by gravity to the sanitary drain/municipal sewer.
Aqua-Stat
A hot water boiler fitting that starts and stops the burner by sensing the water temp
Lumen
The SI units of light intensity
Mixing Valve
Mixes a stream of hot water and one of cold water
Absorbent
A substance capable of extracting one or more parts of a mixture of gases or liquids. It undergoes a physical or chemical change while performing the extraction. They have to be re-charged or replaced at some point. Uses volume.
Adsorbent
A substance with a tremendous surface area that is capable of extracting one or more parts of a mixture of gases or liquids through physical means. It does not undergo a physical or chemical change while performing the extraction.
Cavitation
Cavitation occurs when the liquid in a pump turns to a vapor at low pressure. It occurs because there is not enough pressure at the suction end of the pump, or insufficient Net Positive Suction Head Available (NPSHa). When cavitation takes place, air bubbles are created at low pressure and then collapse when they reach a high-pressure section on the pump impeller. As they collapse they damage the impeller and cause cavitation.
Axial flow pump
Uses a propeller and the liquid flows parallel to the shaft.
Volute or Diffisur
Allows high-velocity low pressure liquid from an impeller to transfer to a low-velocity high-pressure liquid.
Lantern Ring
A metal ring with radial holes is placed in the pump stuffing box to allow entry of sealing or lubricating fluid to the packing.
Caustic Embrittlement
Caustic embrittlement is a type of corrosion that is caused due to high concentration of sodium hydroxide or Caustic Soda (NaOH). It is caused by the formation of irregular cracks on the boiler metal, especially at high local bends such as joints and bends.
Caustic Soda
NaOH or Caustic Soda, or Soda Ash – used to maintain boiler water pH in the 10.0 – 11.5 range. Hydroxide increase boiler alkalinity to prevent acidic corrosion. If heavy scale is present, caustic soda can accumulate to cause Caustic Attack. See pH Treatment
Calcium-Hydroxide – reacts with calcium and magnesium bicarbonates to form sludge that is removed via blowdown.
Phosphates
Phosphate treatment causes calcium and magnesium to precipitate into sludge where it can be removed via blowdown.
Filming Amines
Filming amines function by forming a protective barrier against both oxygen and carbon dioxide attack. These amines form films directly with the condensate line metal and develop a barrier to prevent contact of the corrosive condensate with the return piping. By design, film formers have been developed to function best at a pH of 5.5-7.5. In addition, these amines are highly surface-active and will slough loosely adherent iron oxide and other corrosion products back to receiving points or to the boiler. Care must be exercised with the feed of filming amines.
Hydroxides
Sodium Hydroxide – NaOH or Caustic Soda, or Soda Ash – used to maintain boiler water pH in the 10.0 – 11.5 range. Hydroxide increase boiler alkalinity to prevent acidic corrosion. If heavy scale is present, caustic soda can accumulate to cause Caustic Attack. See pH Treatment
Calcium-Hydroxide – reacts with calcium and magnesium bicarbonates to form sludge that is removed via blowdown.
Oxygen Scavengers
Boiler Oxygen Scavengers are used to remove dissolved oxygen from the boiler feed water and boilers. Dissolved oxygen in the boiler is very corrosive at higher temperatures and pressures. This may lead to localized pitting and premature boiler tube failure or excessive feedwater leaks.
TDS
Total Dissolved Solids
As a result - more and more low-quality wet steam will be generated.
TDS above this range can cause foaming which will result in a carrying of the high concentration of TDS into the steam lines, valves, and steam traps. The increasing level of the TDS is known as “cycles of concentration.” This term is used very often in the operation and control of a boiler system. As a result - more and more low-quality wet steam will be generated and the boiler becomes more susceptible to scale, corrosion, and foaming.
Chelants
Chelants
Chelation depends on sequestration, whereby chemistries bind ions like calcium, magnesium, and iron and keep them in a soluble state. Cleaner boilers can more often be achieved with chelants than with any form of precipitating treatment. However, chelants are usually more expensive than phosphate programs since they react on a mole-to-mole basis.
Air Vent (Hot Water System)
A valve that removes air from the highest point of a coil or piping system.
Clean Steam
Steam that is generated with mineral and chemical-free water to meet regulatory requirements for use in food, drug or medical, or HVAC humidification processes.
EA
Exhaust Air
OA
Outside Air
SA
Supply Air
Air Separator (Hot Water Heating)
Installed on a horizontal piece of pipe that allows air to escape from piping.
U-factor
The overall coefficient of heat transmission of materials such as floors, ceilings, or walls. Can be found in ASHRAE handbook.
CBD
Continuous Blow Down
Boiler Blowdown
Is used to refer to CBD systems. Boiler blowdown is water intentionally wasted from a boiler to avoid concentration of impurities during continuing evaporation of steam.
Boiler Blowoff
The intermintant removal of boiler water to remove sludge
Carryover
The entrainment of water droplets in the steam leaving the boiler drum.
Boiler Boil Out
Used to remove greasy contaminants from the waterside of a boiler by adding caustic soda and then heating the boiler.
Flame Scanner
A device that monitors the pilot and main flame of a furnace. the flame detector consists of ultraviolet (UV) and infrared (IR) sensors that are joined together in a single apparatus. UV sensors work by detecting the UV radiation emitted by the flame and are sensitive to a wide range of flammable fuels including hydrocarbons, sulfur, hydrazine, and ammonia.
Foaming
The continuous formation of bubbles with sufficiently high surface tension. This interferes with the natural steam disengagement process and can result in priming.
Priming
Excess amounts of water droplets are carried with steam being produced causing wet steam. This is usually caused by foaming.
Silica Gel
Silica gel is the most commonly used desiccant for dry boiler storage. A silicon oxide that readily adsorbs moisture, used as an air drying agent
Tridicator
A gauge used on hot water heating systems that indicates water pressure, water height/head, and water temperature.
Accumulator
A low-pressure vessel located between the evaporator and condenser that prevents liquid refrigerant from entering the compressor.
Low Side
Those parts of a compression refrigeration systems exposed to the pressure of the evaporator, such as the accumulator
High side
Those parts of a compression refrigeration systems exposed to the pressure of the condenser such as the liquid receiver
Indirect refrigerant system
A refrigerant system that uses a secondary coolant or brine to cool the space.
Generator/Concentrator (Refrigeration)
A component of an absorption refrigeration system that separates dissolved refrigerant from an absorbent solution, through the application of heat. Also called a concentrator.
NRE
Net refrigeration effect: the heat absorbed by an evaporator during actual operating conditions.
Short-Cycling
The detrimental starting and stopping of equipment in a short period of time.
Subcooling
Cooling a liquid below its saturation temperature.
Superheat
Heating a gas above its saturation temperature.
Acidity
In water: the excess of hydrogen ions over hydroxide ions that occurs where pH is less than 7
Alkalinity
The capcity of water to neutralize acids. This capacity is caused by the water’s content of carbonate, bicarbonate, hydroxide, borate, silicate, and phosphate.
Amines
A broad category of ammonia-derived organic compounds that has various uses in power plants. Can be used to as an oxygen scavenger and to prevent corrosion.
Dissolved Gases
Oxygen and Carbon dioxide
cause corrosion on waterside
Dissolved Solids
Include calcium and magnesium salts that form scale
Cathode
is the negative terminal of an electrolytic cell
lignin
The compound that binds cellulose fibers in wood. Or the glue that holds wood together.
Accumulator
Is a simple liquid trap located in the compressor suction line. It collects and holds the liquid refrigerant so that it does not enter the compressor. Heat absorbed through the accumulator walls vaporizes the trapped liquid and returns it into the compressor. Accumulators have no insulation other wise liquid refrigerant could build up and eventually enter the compressor suction line.
Refrigeration Economizer
1) Reduces temperature of liquid refrigerant which Reduces flash gassing and increases NRE
2) Evaporates any liquid that still has not vaporized through the economizer, this prevents liquid slugging of the compressor
What materials should be used for Ammonia piping?
Only Steel
Pressure Relief Devices & Discharge Rules
CSA 7.2 states that all parts that contain:
liquid refrigerant
Are larger then 152mm internal diameter or has a volume exceeding .085m^3
or parts that can be isolated
Must be protected with a pressure relief device and these devices must discharge outside of the building
Why is Refrigeration System Purging required?
Is used to remove non-condensable (Air) gases that have leaked into the system through improper operation or maintenance of the system. These non-condensable gases increase the high side pressure that corresponds to the saturation temperature of the refrigerant. As pressure increases so does the temperature. In order for the system to condense the refrigerant is now consumes more power, reduces condenser capacity, and overstresses the compressor parts due to the higher temperature present.
How does refrigeration purging work?
Purgers refrigerate the mixture of refrigerant and on-0condensable gases (air). The resulting liquid refrigerant returns to the receiver and the non-condensable gases are vented to the atmosphere. Some purgers also eliminate water or moisture from the system.
Main difference between compression and absorption refrigerant systems?
Compression systems use mechanical energy (electric motor/steam turbine) to drive a compressor
Absorption systems use heat energy to drive the refrigeration process but do not use compressors.
What increases the amount of salt such as lithium bromide, water can hold?
An increase in temperature will increase the amount of salt water can hold and the inverse is also true.
When does Crystallization of salt occur in water?
Occurs when the amount of salt that water can hold is exceeded. This can happen because either the temperature of the solution decreases, which reduces its capacity top hold salt. Or the amount of salt being added exceeds the waters maximum solubility level for the current temperature.
Main Differences between Ammonia and Lithium Bromide Absorption systems?
Ammonia Systems are used for cooling in industrial applications such as cold storage, food processing but not HVAC because of ammonia’s toxic properties
They use water as the absorber
They are under pressure but not under vacuum
Lithium bromide use water R-718 as its refrigerant and is used for HVAC service
They are hermetically sealed, meaning they are completely seal welded
All lithium bromide systems include internal purge systems to remove any air that may enter the system because of the vacuum required for operation
They are kept under extreme vacuum because of R-718’s properties and saturation temperatures required.
Lithium bromide is used as the absorber
Camshaft
A camshaft is a rotating object— usually made of metal— that contains pointed cams, which converts rotational motion to reciprocal motion. Camshafts are used in internal combustion engines generally to reciprocate the intake and exhaust valves of the combustion chamber
Connecting rod
Connects a piston to the crankshaft
Counter-flow
When two fluids move in opposite directions from one another. Generally seen in heat exchangers
Cross Flow
When two fluids move at 90 degrees in relation to one another. Can be seen in heat exchangers like cooling towers.
Drift Eliminators (Cooling towers)
Removes water mist from the air before it can leave a cooling tower and enter the atmosphere.
Eccentric
Is an off-center mechanism that converts rotary motion into a reciprocating motion by virtue of having its rotational center located at a distance from the rotational center of the device to which it is attached.
An example of this is a rotary vane pump
Flywheel
a device that alternately stores and releases kinetic energy
Four stroke engine
an engine that requires two crankshaft revolutions to complete one working cycle
Two Stroke Engine
An engine that requires one crankshaft revolution to complete one working cycle.
Heat Engine
A machine that converts heat energy to mechanical energy through a series of repetitive thermodynamic operations such as combustion, compression, expansion, boiling, condensation, and cooling.
Hot Well
A reservoir at the base of a steam condenser in which condensate accumulates
Thermowell
A place for a thermometer to be placed into a machine or vessel
Regenerator (Gas Turbines)
A heat exchanger that recovers heat from exhaust fluids.
Regenerator (Gas Turbines)
A heat exchanger that recovers heat from exhaust fluids.
Differences between Impulse and Reaction steam turbines?
Impulse turbines are bucket shaped and use the velocity of the steam to push the blades. Impulse turbines experience very little pressure drop but velocity of the steam decreases through each set of turbines.
Reaction turbines use the shape of their blades to push the steam like a rocket or nozzle. The steam is directed in such a way to create thrust. The thrust generated turns pressure into velocity. Reaction turbines are generally located after impulse turbines in larger power generating systems because they can use the high pressure and low velocity left overs from the impulse turbines.
Journal Bearings
Are metal sleeves that contain bearings used to support radial loads. A journal bearing is a bearing that allows a shaft to rotate freely within a supporting sleeve or shell. The part of the shaft which fits in the bearing is the journal, giving rise to the name. Unlike roller and ball bearings, journal bearings do not have any rolling elements.
What are Thrust Collars/bearings?
They are bearings that support an axial load on a shaft. They keep the shaft from moving in an axial direction. The most common in the tilting pad thrust bearing, which do not allow for metal on metal contact and maintain an oil wedge ( fluid film lubrication)
Oil Wedges
Creates a fluid film lubrication to prevent metal to metal contact. They support the load as well.
True Brinelling versus False Brinelling
True Brinelling is caused by the improper installation of a anti-friction bearing. The bearing is placed or forced to roughly into the track and causes an indentation under the balls or track of the bearings. This causes the bearings to experience rough operation and failure. The damage done during installation causes forces to be applied unevenly.
False Brinelling: is caused through excessive vibration of the equipment which applies the forces onto the bearings unevenly. This leads to bearing failure as well but for different reasons.
Difference between Cellulose and Lignin?
Lignin is the glue that holds wood together. Susceptible to delignification a chemical attack.
Cellulose are the long fibers that give wood its strength. Biological attacks involve microorganisms that attack the cellulose and break it down.
Shaft Sleeve
A protective or sacrificial cover for a shaft used underneath compression packing to absorb the abrasive oxides that the packing absorbs from friction with the metal shaft or sleeve.
It protects the metal shaft from damage inside of a pump and can be replaced cheaply every so often as it becomes worn out form the friction of the packing material.
Huddling Chamber
Part of a pressure relief device that is a compartment below the valve disc. As the steam pressure increases the area of the huddling chamber also increases allowing the valve to pop open and for steam to escape.
Pressure relief device blowdown
The difference between the popping pressure and actual reseating pressure of the pressure relief device. A minimum of 15 kpa or 2% of the popping pressure is required by AMSE Part PG-72.1 code.
What dissolved Gases causes corrosion?
Oxygen and Carbon Dioxide
Oxygen can cause very localized corrosion called pitting
Carbon Dioxide raises the Ph as it is formed into carbonic acid and corrodes condensate return lines.
They can both be removed through the use of a Deaerator
Hard Water
Hard water is water that has high mineral content (in contrast with “soft water”). Hard water is formed when water percolates through deposits of limestone, chalk or gypsum which are largely made up of calcium and magnesium carbonates, bicarbonates and sulfates
Soft Water
soft water, water that is free from dissolved salts of such metals as calcium, iron, or magnesium, which form insoluble deposits such as appear as scale in boilers
Dry-Bulb Temperature
Simply measures the temperature of air and does not take into account evaporation or wind chill
Wet-bulb Temperature
Is the temperature indicated by a bulb covered by a water wetted wick, which is exposed to stream of rapdily moving air. It measures the dry bulb temp and then subtracts the cooling effect of evaporation or wind chill.
What does dissolved oxygen cause in boilers?
Pitting
