Ammonia Systems Powerpoint Flashcards
What kind of applications is Ammonia used in?
Large commercial and industrial
Ammonias Nre’s are in the range of ____btu/lb (latent heat)
565
The pure anhydrous ammonia used as a refrigerant is referred to as R-___
R-717
Properties of Anhydrous Ammonia:
- Boiling point: ___
- Specific gravity (Water = 1) : ____
- Vapour density (Atmosphere pressure, Air = 1) : ___
- Available latent heat (at 5F) : ____ but/lb
- -28F (-33C)
- 0.618
- 0.6
- 565 btu/lb
Name 3 health hazards of ammonia based on container label
- Flammable and explosive under certain conditions
- Reacts with common acids, chlorine, and other halogens
- Corrosive to metals and bodily tissue
Suppliers of ammonia are required to make available a ______ data sheet (MSDS) on ammonia
safety
Ammonias largest health hazard is due to its toxicity. Both liquid and gaseous ammonia combine with ______ to form ______ ammonia, a basic, or caustic alkali, which burns, irritates, and corrodes
moisture, aqueous
The effect of aqueous ammonia is most pronounced on moist parts of the body such as
eyes, linings of the nose, mouth, and respiratory tract, and sweaty skin.
Concentration of ammonia gas in air is described in
parts per million
- 5 ppm effect:
- 20 ppm effect:
- 25ppm effect:
- some people can detect odour
- usual odour threshold
- recommended 8 hour exposure level
- 35 ppm effect:
- 50 ppm effect:
- 100 ppm effect:
- recommended short-term (15 min)
- maximum permissible 8 hour
- strong smell, irritating to nose
- 200 ppm effect:
- 400 ppm effect:
- 500 ppm effect:
- eyes start to water after few min
- major nose and throat irritation, eyes running heavily
- immediately dangerous to life or health (I.D.L.H.)
- 1000 ppm effect:
- 5000 ppm effect:
- 15000 ppm effect:
- breathing intolerable
- respiratory system shut down; fatal quickly
- major burns to unprotected skin
Ammonia is not a cumulative poison, and is not generally thought to cause cancer or _____ defects
birth
Secondary problems such as eye pain and vision loss and pulmonary restriction may occur ____ or even ____ after initial exposure
hours or even days
Liquid ammonia also has a freezing effect on body tissues. It is likely to be cold when it hits, and chill more as it evaporates from skin or eyes causing ___ ___
frost bite
Liquid ammonia is not flammable. Ammonia gas, however, in concentrations of __ to __% in air, is flammable
16-25%
If ammonia gas has oil droplets suspended in it, the flammability hazard increases considerably, down to as low as _%
4%
Explosions are rare, therefore. In fact, the DOT classifies ammonia for transportation purposes as a ___-______ compressed gas
non-flammable
Do not cut or weld containers, vessels, or components that may contain ammonia. Make sure they are fully ______ first
ventilated
Ammonia fires and explosions can occur. If enough gas leaks out of a vessel or container and enough air leaks in, the right concentration for ________ may occur inside
flammability
Ammonia is chemically _____, it will not easily separate into its components, nitrogen, and hydrogen.
stable
As a strong base, or caustic alkali like lye, ammonia will burn and eat away many substances, besides _____ _____
human tissue
______ and alloys that contain ______ are particularly vulnerable, and are never found in ammonia systems.
copper
Leaks are most likely located in the ___ where most of the piping is.
MER: Mechanical equipment room
Ammonia emergency equipment should be readily available in the MER, this includes; name 4
- rubber gloves
- a rubber apron
- a full-face gas mask with fresh ammonia canisters
- self-contained breathing apparatus
Emergency system shut-down instructions should be posted by system controls, usually on the _______
compressor
A system ______ should also be posted where it can be consulted quickly
schematic
Before entering the MER, the ammonia concentration should be checked with an _______ detector. If the reading is above 100ppm, use at least tight-fitting ____ and a respirator with ____ ammonia cartridges
electronic detector, goggles, green
If the reading in a MER is 1000 ppm or more, use at least a full face gas mask with an _____ _____
ammonia canister
If the reading in a MER is over 2500 ppm, use at least a gas mask with an industrial sized 2 hour canister, or a type _ air supplied respirator, with full face protection or preferably, full head protection
C
If the reading is over _____ or more ppm, self contained breathing apparatus is necessary, with a full suit.
10,000
Additional emergency equipment that should be available outside the MER; name 3
- a full rubber or plastic suit with boots and gauntlet-type gloves
- a shower or drum of at least 50 gallons of water
- plans and schematics
No one should enter a contaminated MER ____
alone
When you are working on an ammonia system keep in mind that what you are about to do may cause a sudden leak. Carry an escape ______
respirator
Before commencing any work, always plan your
escape route
What is the first step when ammonia burns or irritates eyes or-skin?
flush the affected area with lots of clean, cool, water as quickly as possible and for at least 15 min
What is the point of using water on an ammonia burn?
to absorb and dilute the ammonia concentration
Should you remove clothing while flushing ammonia burns
No, do it immediately
DO not wear _____ _____ when working with ammonia
contact lenses
Do not apply any kind of ____ or ointment to burns
oil
The first treatment when you have breathed ammonia is to
get to clean air as soon as possible
Liquid ammonia ______ as its temperature rises
expands
Standards require that any pipe or vessel which could be valved off full of liquid ammonia must have _____ valves to ____ excessive pressure
relief, vent
There must be enough room inside an ammonia tank so that the liquid can ______
expand
T or F
It is crucial an ammonia tank is not overfilled especially when transferring liquid ammonia from a full container to an empty unpressurized one
True
Never fill ammonia containers more than __%
80%
Compared to common halocarbon refrigerants, ammonia is _____ in both liquid and gaseous form
light
Liquid ammonia is _____ than water
lighter
Gaseous ammonia, under atmospheric pressure, is _______ than air
lighter
Ammonia has a very high _____ heat and ______ heat making it a great refrigerant
sensible, latent
Ammonia systems and storage tanks should be evacuated before charging to remove ______
moisture
______ is difficult to remove from ammonia
moisture
The approved way to discharge ammonia from a system is to vent it as a ___ into a drum of water. Have at least a _____ of water per pound of ammonia
gas, gallon
NEVER dispose of any ammonia or contaminated water to flow into any surface _____ bodies
water
Surface water bodies include;
drainage ditches, storm water and sanitary sewers, wetlands, ponds, lakes, and streams
Common oils, and ammonia liquid or gas are mutually _____
insoluble
Traps for draining oil are typically provided at recirculation tanks and sometimes at _____
chillers
There must be __ stop valves on every component in an ammonia system
2
Multiple valves are useful when system requires service because it allows you to ______ components and keep system running
bypass
Locate stop valves in _____ and _____ lines to all components such as condensers, evaporators, receivers, and accumulators
inlet and outlet
Make sure globe valve stems are mounted ______ with respect to a horizontal pipe run.
vertical
Why are valve stems mounted vertically?
reduce chance for dirt or scale to lodge in valve seat and reduce chance for liquid refrigerant or oil to pocket in the area below the seat
pressure regulators, solenoid valves, thermal expansion valves, should be _____ for easy removal or welded
flanged
The use of a strainer should be used whenever possible to protect system components from pipe _______ material
construction
Solenoid valves should be located in the ______ position and protected from ______
upright, moisture
Purpose of water jackets on ammonia compressors?
to prevent carbon build-up on heads of compressors
Two types of water cooling or liquid ammonia expansion in heads controlled to a temp above __F by a back pressure ______
32F, regulator
First stage compression such as rotary are normally cooled by ____ circulated through heads for cooling
oil
Which agent for cooling compressor heads is the best and why?
Glycol because it does not boil or freeze
Any ammonia vessel that can be valved off must be provided with an automatic _____ valve
relief
___ relief valves are normally used
dual
dual relief valves on ammonia systems are ____-way stop
three
Dual relief valves are constructed so that it is always open to one or the other relief valve if the other must be removed for ______
servicing
What makes ammonia a great refrigerant?
- it is cheap to use
- occurs naturally
- has an ozone depletion of zero
Oil stills are normally connected to the bottom of ammonia flooded ______ to remove excess oil trapped in the chiller
chillers
Suction Traps or (Suction Traps with Pump)
- Every system should have an adequately designed _______ trap
- Suction traps protect the compressor against ____ _______ during operation
- Systems with pumps, operate by returning liquid in the trap to the high pressure ______
- suction
- liquid floodback
- receiver
Liquid Recirculation Systems:
In liquid recirculation systems, A pump or pumps, circulates the ammonia from the low pressure receiver to the _______
evaporator
Liquid Recirculation Systems:
- Relief valves on low pressure receivers are normally set at ___psig
- Liquid levels in low pressure receivers are normally controlled by ______ _____ ______
- 40psig
2. electric float switches
How often should an ammonia plant inspection be conducted?
minimum two per day
Ammonia Plant Maintenance Procedures; name a few
- drain oil from chiller tank as required
- change oil filters
- check belt tensions
- check drive couplers
- check brine pump operation
Drainage of Oil from Chiller or Still:
- If possible oil should be drained when there are no….?
- Prior to draining oil the worker shall inform his _____ of his intent
- members of the public in the facility
2. co worker
Drainage of Oil from Chiller or Still:
- Prior to entering the class T mechanical room ensure all __________ systems are functioning, and it is safe to enter
- Workers should wear a full face mask respirator and _____
- Open ______ in a manner which allow only the slow release of oil and oil foam from the chiller
- ventilation
- gloves
- valves
Drainage of Oil from Chiller or Still:
- Drain into a container of water through a transparent ____ immersed in to water
- Stop flow when ______ gas/liquid appears
- At no time should the spring return valve (_______ valve) be wired open or left unattended
- hose
- ammonia
- dead man valve
Relief Valves and Safety Controls
- Each relief valve and safety control should be tested each year in accordance with the ___ boilers and pressure vessels act
B51
Vessels and Piping:
- All vessels and piping should be clean and _______
- Do not paint valves or controls as they may become _____ and inoperative
- All piping should be colour coded as per ___ mechanical code
- painted
- sealed
- B52
Condensers: Evaporative
- Maintain proper _____ treatment
- De-scale as required
- Ensure clear operation of sprays ______
- Maintain belts and pulleys and ensure _____ are in place
- Check water make up and _____ assembly
- water
- yes
- monthly
- guards
- float
Condensers: Air Cooled
- Check heat exchanger surfaces and ___
- _____ are in place
- fan
2. guards
Ammonia pipe markers should have four sections plus directional arrows: name them;
- _____ body
- _______ state
- ______ level
- _______ identification
- ______ to indicate ____ _________
- marker body
- physical state
- pressure level
- piping identification
- arrows to indicate flow direction
Piping identification:
Marker body shall have the word “AMMONIA” in black letters on a ______ background
yellow
Piping Identification
The physical state of refrigerant is located to the left of the marker body and the word “AMMONIA”. This is indicated as follows;
a) If liquid - “LIQ” in black or white on an _____ background
b) If vapour - “VAP”in black or white on a ____ background
c) If both “LIQ” “VAP” both printed on _____ above
a) orange
b) sky blue
c) colours above
Piping identification:
The pressure level of the refrigerant is located to the right of the word “AMMONIA”
a) If high pressure - more than ___psig “HIGH” in black or white on ___ background
b) if low pressure - ___psig or less “LOW” in black or white on ____ background
a) 70psig, red
b) 70psig, green
Piping identification: directional arrows;
These arrows are located at the ____ of the marker body, physical state, pressure level, and piping abbreviation labels. These arrows could be at one or both ends
ends
Where do you find ammonia equipment room requirements?
B52 code book
Class T Machinery Room:
- No ____ producing device
- ____ door requirement
- Vestibule requirement
- Tight construction
- Openings sealed
- Ventilation requirement
- Switch location
- Alarms and _______
- flame
- exit
- detectors
