Timothy
G. Prather
University of Tennessee Extension
This
manual was prepared to inform Tennessee farmers and firefighters
about causes, prevention and control of silo fires. The information
contained herein is believed to be accurate and up-to-date.
However, the University of Tennessee Agricultural Extension
Service will not be responsible for accidents, injuries nor
any other losses resulting from the application of practices
described in this publication.
Portions
reprinted with permission from the publication "Extinguishing
Silo Fires" published by the Northeast Regional Agricultural
Engineering Service, Riley Robb Hall, Cornell University,
Ithaca, NY 14853.
Occasionally,
we hear reports of an upright or tower silo containing a fire.
The majority of these silo fires are slow, smoldering ordeals
that become a frustration to farmers and fire fighters. A
few have resulted in raging fires or explosions, some with
fire fighters being injured or killed.
A variety
of conditions are possible when fires are in conventional
silos. Often, the first sign of fire is a piece of burned
door that falls down the chute. Other signs may be blackened
or glowing red silage, smoke pouring out of the silo or a
burnt odor around the silo.
Burning
silage in silos can be hazardous. Know what the hazards are
and act accordingly. Of course, the best way of dealing with
silo fires is by preventing them.
A few silo fires are caused by unloading equipment. Electrical
problems, overheated bearings and slipping belts can ignite
dust and dry materials on the equipment. Proper maintenance
of the silo unloader will extend the service life of the equipment
and reduce potential for fire. Refer to the equipment owner's
manual for maintenance guidelines.
The
more troublesome fires, however, are those resulting from
spontaneous ignition within the stored silage. The leading
cause of this type fire is low moisture silage and air leaks
in the silo. Air enters the silo through cracks in the walls
or around poorly fitting doors. Poor distribution of material
during filling may result in poor compaction and contribute
to fires.
Silage
is formed when forage crops are allowed to ferment in the
absence of air. The bacteria responsible for fermentation
produce a certain amount of heat, thus silage will be fairly
warm during this process. Low moisture content and the presence
of oxygen may allow the microorganisms to reproduce too rapidly
and generate heat faster than normal. The silage surrounding
an area with excessive heat generation acts as insulation,
so temperatures can climb quite high and combustion may occur.
The best method of dealing with silo fires is by prevention.
Proper management of your forage system will prolong the useful
life of the structures and equipment, produce a higher quality
feed and prevent fires and other problems.
Silos should be inspected at least annually and any damage
repaired. Look for structural weaknesses and seal any cracks
which could allow air to reach the ensiled crop materials.
If the wall can be readily scratched with a coin or if scaling
is detected have the wall treated or sealed. Don't forget
to check the doors to see that they fit properly. Replace
any doors showing signs of decay, as they could result in
a fall should a step break loose when someone climbs the chute.
Harvest
crops at the proper moisture content (see Table 1) and distribute
the material properly inside the silo. Proper distribution
results in better compaction and keeps air from reaching the
feed. Proper distribution also increases silo capacity and
places a more even load on the silo walls, avoiding possible
structural damage (see Figure1).
When
the silo is empty, inspect and repair the unloader system.
Check all belts, bearings, wiring and motors and repair any
damage. Inspect and lubricate the unloader lift cable to prevent
a dropped unloader. If the lift cable shows any indications
of a kink, cut or corrosion, replace it immediately. Carefully
examine the unloader power cable for damaged insulation and
terminals. Nicks in the outer insulation may be safely repaired
with electrical tape, but more serious damage will require
replacement of the cable.
DANGER: Oxygen-limiting silos may explode if water or foam
is sprayed through the top hatch or if the hatch is opened.
Refer to the section on oxygen-limiting silos for recommendations.
Conventional
Silo
Conventional upright silos are typically constructed of concrete
staves held together by pre-tensioned steel rods (see Figure
2). Some may be built of wood, reinforced concrete, glazed tile
or brick. A few oxygen-limiting silos have been converted to
conventional, top-unloading type. These silos are filled and
unloaded from the top. The unloader rests on the feed surface
and removes a layer of silage as it rotates. A blower sends
the material out one of the doors and down the outside chute
for feeding.
The
wooden unloading doors typically have a latch mechanism and
metal rungs which serve as a ladder inside the chute. The
typical chute is approximately 36 inches wide and 28 inches
deep, so movement with an air pack or a second person (accident
victim) is difficult. Some conventional silos ave an inside
chute which is formed as the silo is filled (Figure 3). The
top unloader operates similarly to those in other conventional
silos, except the silage drops down this inside chute to a
conveyor at the bottom.
When
a silo fire is detected, call the fire department immediately.
After the fire department is notified, farmers should attempt
to close the bottom of the chute to limit air movement through
it until the fire department arrives. Air moving through the
chute will fan the fire. Use select metal or other non-combustible
materials to close the chute.
Remove
livestock and machinery form exposed and adjacent buildings.
Wet the area around the silo to keep the fire from spreading.
Cover openings in nearby buildings with non-combustible materials
to keep out sparks or embers.
Be alert
to the presence of toxic gases inside silos (see Table 2).
IF only light puffs of smoke are visible, it may be safe for
inspection and temperature checks without a self-contained
breathing apparatus (SCBA). If there is continuing smoke or
glowing embers, have the first person who climbs the chute
to assess the situation wear a SCBA.
Table 2. Characteristics of Dangerous Gases That May Be Present in Silos. |
Gas
| Health Effects
| Exposure Level Maximums*
| Physical properties
| Flammable Properties
|
Acute
| Long Term
| Immediately Dangerous to Life and Health
| Short-Term Exposure**
| 8-hour Work Day
| Density (Air=1)
| Color
| Odor
|
Carbon Monoxide (CO) |
Asphyxiant |
-- |
1,500 |
400 |
50 |
.97 |
Colorless |
odorless |
Explosive between 12.5 % and 74% by volume of air mixture. auto ignites as 1128°F (609°C) |
Carbon Dioxide (CO2) |
Asphyxiant |
-- |
50,000 |
15,000 |
5,000 |
1.52 |
colorless |
odorless |
Non-flammable |
Nitrogen Dioxide (NO2) |
Respiratory Irritant |
Permanent Lung Damage |
50 |
No standard presently in effect |
3 |
1.16 |
reddish brown |
strong pungent |
Non-flammable but will support combustion |
Nitric Oxide (NO) |
Asphyxiant |
-- |
100 |
35 |
25 |
1.53 |
colorless |
strong pungent |
Non-flammable but will support combustion |
* Numbers represent parts of gas per million parts of air (ppm).
** Fifteen-minute exposure, maximum four exposures per eight-hour day with 60-minute intervals between exposures.
Carbon monoxide is formed in small quantities during fermentation. Once a fire starts, however, incomplete combustion of cellulosic materials (such as silage) forms larger quantities.
Carbon Dioxide is present in small quantities in a flaming fire or after complete combustion. Carbon dioxide is non-flammable and heavier than air. At low concentrations, it is non-toxic, but at higher concentrations, it displaces oxygen and acts as an asphyxiant.
Nitric Oxide and Nitrogen Dioxide are poisonous gases which form when nitrogenous organic compounds (such as silage) burn. These gases also occur as by-products of silage fermentation. The highest levels are present during the first 48 hours after the silage is put into the silo, but dangerous levels may persist for up to three weeks. Nitrogen dioxide is the most dangerous and most likely to be present in the silo.
|
Whether
fire is suspected or evident, use a lifeline and never step
directly on the silage surface. Place boards, pieces of plywood
or ladders on the surface to distribute weight over a larger
area. This will minimize the risk of falling into a burned
out cavity.
The lifeline should be tied as high as possible to a beam,
hoop or other structural member of adequate strength. This
can be a rope from a double bowline soling, a harness or upper
"O" ring on the SCBA. Station a second person in the chute
to observe and assist. Radio communication with the ground
is recommended.
Auxiliary
lighting is often needed in the silo. Lights can be positioned
from the silo filling platform.
Step
I - Size Up the Situation
Observe
as many conditions as possible about the fire. The exact location
may not be known. Although the fire may be anywhere within the
silo, chances are it is near the top. The majority of fires
occur in the top 10 feet of silage, and within this range, most
occur in the top four to six feet (Figure 4). Fires often originate
near the unloading doors where air leaks dry the silage, but
can occur at any point where the material is too dry. The first
indication of a fire is often the burning of an unloading door.
If considerable
smoke is pouring out of the silo, farmers should not attempt
to enter the silo or chute. This should be left to firefighters
wearing full turnout gear and a self-contained breathing apparatus
(SCBA).
Step
2 - Knockdown Surface Burning
By the time
the fire department arrives, the silo fire may have well-established
flames. Unloading doors may have burned through and flames may
extend up the chute. As with any Class A fire, douse and ventilate.
Water will cool the fire and keep flames from spreading.
Experience
has shown that a straight tip nozzle is more effective than
a fog or spray. The stream of water from a straight tip nozzle
penetrates the pile and better extinguishes a fire that has
become deep seated. A 3/8" tip is recommended. After the surface
fire is extinguished, then procedures for extinguishing a
subsurface fire are employed.
Remove
unloading doors and coverings to allow hot gases, smoke and
steam to escape.
Dousing
is effective only if water reaches the fire, thus limiting
its application to surface burning. One firefighter, in full
turnout gear with lifeline and SCBA, dousing from the filling
platform or from the chute is usually sufficient to extinguish
all surface burning.
CAUTION:
Do not attempt to extinguish a silo fire by pumping large
quantities of water onto the surface of the silage, hoping
it will soak in and cool the fire - it won't work. Water will
not penetrate the silage well enough to control the fire in
this manner. In addition, the silo cannot withstand the higher
lateral pressure created by the water and structural damage
may result (Figure 5).
Step
3 - Temperature Readings One of the
keys to extinguishing fires in a conventional silo is to find
the exact location of the fire. This can be done with an easily
constructed probe and a thermometer (Figure 6). Other temperature
sensing devices are available which can be used alone or with
the probe. Each fire department should have a probe and thermometers
to locate hot spots in silage or hay.
A firefighter
standing on a ladder, boards or plywood pushes the probe into
a suspect area and lowers a thermometer into the probe using
a light wire (Figure 7). After a few minutes the thermometer
is retrieved and observed.
Make
several temperature readings, starting near obvious hot spots
and moving toward the silo walls at three foot intervals.
If the fire is caught in its earliest stages only one hot
spot may be present. However, there may be several hot spots
because the fire will follow air layette to support itself.
Consequently, take several readings across the silage.
How
deeply a probe can be pushed into the silage depends on the
condition of the silage. A probe will penetrate easily into
a charred or burned spot. On the other hand, it is difficult
to push the probe more than 4 to 6 feet into packed, finely
chopped silage.
Temperatures
below 140°F indicate no particular heating problem. Temperatures
of 140 to 170°F are difficult to interpret. Heat moves
slowly through silage and silo walls, so readings in this
range may indicate the silage is heating or it is gaining
or losing heat from another hot spot. Repeat the temperature
reading every two or three hours to check for dangerous heating.
If the temperature is 180°F or higher the silage will
eventually char, smolder or burn.
Step
4 - Water Injection After determining
the location and extent of the fire, inject water directly into
the hot areas using the probe. Work slowly and methodically.
Leave the prove in place for several seconds to several seconds
to several minutes, depending on the size and temperature of
the hot spot. The goal is to cool and raise the moisture content
of the hot spot to safe levels.
Water
may be injected from the silo chute, especially when a door
has burned through. Be prepared for considerable amounts of
steam and smoke which may blow back.
The
firefighters using the probe must wear full turnout gear and
a lifeline. Station a second firefighter, also in full turnout
gear, inside the chute to help handle the hose and assist
as needed. This is especially important if the probe operator
goes inside the silo.
A water
gas explosion from injecting water into burning silage is
not a realistic concern in conventional silos. The few explosions
that have been reported from silage fires have all been in
oxygen-limited silos where there was a build-up of explosive
gases.
The
water gas reaction occurs when water molecules react with
very hot carbon to form hydrogen and carbon monoxide. The
reaction is highly endothermic, or it absorbs heat, so the
temperature of the material drops rapidly. Consequently, when
water hits the hot silage, the instantaneous cooling effectively
prevents the water gas reaction.
Another
important factor practically prevents explosions in conventional
silos. For an explosion to occur, there must be containment
of the right proportion of air (or oxygen and an explosive
gas (like carbon monoxide). There is no containment of gases
in a conventional silo.
Water
Additives
Fire in a silo does not change the characteristics of chemicals
that may be added to water as an aid for extinguishment. Chemicals
that help water to absorb heat would do the same if used on
a silo fire. If mixed according to the label, there are no
adverse effects to the silage. Chemicals that reduce water
friction do not hurt, but are of no particular help because
large quantities of water are not generally used.
Gases,
such as carbon dioxide or nitrogen, may be injected into conventional
silo fires in a manner similar to injecting water. The expense
of these materials and cold weather problems make water a
better choice. In addition, gases do not correct the major
cause of silo fires - dry material.
Step
5 - Unload the Silo Unload the
damaged silage because:
- overheated
silage loses its nutritional value
- the
wetted silage will spoil
- any
hot spots which were missed or not cooled sufficiently may
ignite
There
is a section later in this manual which covers some of the
problems or potential hazards to consider when unloading the
silo.
Advanced
Fires in Conventional Silos
A silo fire may smolder or burn for days or even weeks before
discovery. A silo fire in the advanced stages rarely remains
below the surface or deep within the mass of silage. Instead,
it travels horizontally toward the walls of the silo or vertically
to the upper surface of the silage (Figure 8).
Silage
shrinks as it dries and becomes excellent fuel for a fire.
There may be an air space as much as several inches wide between
the silage and the silo wall. Unloading doors in a conventional
silo often leak air and permit a column of silage to dry and
shrink for some distance down the silo. This leaves a column
of dry fuel along the doors.
When
fire reaches any of these areas of dry fuel and abundant air
it burns freely rather than smoldering. If this occurs, attack
the surface fire before attacking the subsurface fire.
Experience
has shown that a straight tip nozzle is more effective than
a fog nozzle on silo fires. The solid stream of water from
a straight tip penetrates the burning material better. A 3/8
inch tip is recommended.
Fire
Along the Unloading Doors Fire along
the column of dry silage behind the unloading doors is the most
common example of advanced burning in a conventional silo. Attack
these fires as follows:
- Follow
good safety practices. Wear full turnout gear, SCBA and
a lifeline if possible. Do not enter the silo unless absolutely
necessary. Instead, work from inside the chute.
- Extinguish
all surface burning through burned-out openings in the doors.
The doors usually have openings that have burned through,
allowing access to the fire. Chopping through a door that
is not burned will be most difficult in the confines of
the chute and is probably not necessary.
- Extinguish
all subsurface burning using short probes inserted in the
silage in all directions. This, too, can be done through
burned-out door openings.
- After
the fire is extinguished, replace burned doors with new
or rebuilt ones. Backfill dampened silage into burned-out
cavities and level the top surface of the silage so the
farmer can immediately begin the unloading process.
NOTICE:
In some cases the fire may be so advanced that extinguishing
the fire is impractical. For example, if the fire started
near the bottom of the silo and has progressed to the top
of the chute as well as several feet back into the silage,
it may be best to allow the fire to burn out on its own. It
is possible to put out the fire, but it may reignite and unloading
will be dangerous. If it is determined to allow the fire to
burn out, take steps to prevent spread of the fire. Be aware
that the fire may smolder for several weeks or months.
Fire
in a Horizontal Pattern The next
most common example of an advanced fire is burning around the
silo wall. The burn pattern is usually a trench-like burned
area around the silo three or four feet deep. Attack these fires
as follows:
- Extinguish
all surface burning using a straight tip nozzle. Start the
knockdown just inside the nearest unloading door, advancing
half way around the ring. Retrace your path and work your
way around the other half of the ring until you reach the
far side. You must:
- lay
planks or other support to walk on
- wear
full turnout gear and SCBA
- use
lifelines
- Extinguish
all subsurface burning using probes.
- Backfill
with dampened silage and level the surface to prepare for
unloading.
Oxygen-Limiting
Silos
Oxygen-limiting or "sealed" silos are exactly what their name
implies. Properly managed silos of this type contain very little,
if any, oxygen. This is intended to keep spoilage to an absolute
minimum, resulting in a higher quality feed. Oxygen-limiting
silos have no outside chute and unload from the bottom (Figure
9). Top hatches and unloader doors are to remain closed except
when they are being used. The most common brand of oxygen-limiting
silo in Tennessee is Harvestore.
Spontaneous
ignition fires in oxygen-limiting or "sealed" silos are rare,
but they can occur with improper management. The basic rule
for these silos is to keep all openings closed, except when
filling the silo or operating the unloader. Excluding air
preserves the silage and prevents fire. Even with drier silage
at 45 percent moisture content, there is usually insufficient
oxygen to support a fire after an oxygen-limiting silo is
filled and sealed, A slow charring fire will sometimes suffocate due to insufficient oxygen.
A fire
in an oxygen-limiting silo is potentially very dangerous.
There have been explosions when firefighters attempted to
extinguish the fires. To prevent explosions, do nothing that
could allow oxygen to enter the silo. Follow proper procedures
for maximum safety.
The
airspace above the silage in an oxygen-limiting silo will
contain smoke and carbon monoxide along with other gases and
some oxygen during a fire. Any action which introduces additional
oxygen may produce an explosive atmosphere which may be ignited
by the burning silage. If this occurs, the pressure created
by the burning gases cannot be vented through the top hatch
and an explosion will result.
DO
NOT USE WATER OR FOAM to fight a fire in an oxygen-limiting
silo. Opening the top hatch to apply water or foam will allow
oxygen to enter. The stream of water or foam will carry large
amounts of air into the silo. In addition, the steam formed
when the water reaches the fire may also contribute to an
explosion. Signs to warn of this danger are available (Figure
10).
Fires in oxygen-limiting silos are discovered if burnt or
burning material comes out the unloader, or if smoke is escaping
from the top hatch. When a fire is discovered, seal the unloader
opening or hatch. Next, seal all openings such as manhole
covers and drain caps used for maintenance.
If the
silo is cool and quiet, and if minimal smoke is escaping,
carefully climb the silo and close the top hatch or any other
openings. Do not lock or latch the top hatch. Closing the
hatch will prevent oxygen from entering the silo, yet pressure
increases can be relieved safely.
Leave
the silo closed for up to three weeks to allow the fire to
use all oxygen and self extinguish. During this time, make
temperature readings of weekly samples from the unloader to
be sure the fire is extinguished.
If the
silo is producing considerable smoke or steam, or if the silo
is rumbling, leave the hatch alone. Closing the hatch on an
active fire could bring carbon monoxide and air mixtures into
the explosive range.
If sealing
the silo does not extinguish the fire, inject nitrogen or
carbon dioxide to displace oxygen and cool the fire. Be careful
not to introduce additional oxygen. Most oxygen-limiting silos
have pipe nipples for injecting these gases. These nipples
should be inspected annually to insure they are open and useable.
If nipples are not present, have the farmer install one or
have one installed by the manufacturer or dealer. Table 3
lists the amounts of gas needed for various sized silos
To Inject
Gas Into a Sealed Silo
Table
3. CO2 or N2 Quantity Required
to Extinguish Fires in Oxygen-Limiting Silos |
Silo
Size
(dia x ht (ft)) |
CO2
(no. 50 lb.
cylinders) |
N2
(no. 50 lb.
cylinders) |
20
x 60 |
20 |
40 |
20
x 70 |
22 |
44 |
20
x 80 |
30 |
60 |
24
x 60 |
30 |
60 |
24
x 70 |
35 |
70 |
24
x 80 |
40 |
80 |
30
x 60 |
45 |
90 |
30
x 70 |
50 |
100 |
30
x 80 |
60 |
120 |
SOURCE:
NRAES-18, Extinguishing Silo Fires |
- Remove
cap from the pipe nipple.
- Connect
reducers, bushing, shut-off valve and other fittings as
required to connect the silo nipple with the appropriate
regulator using a number 88 hose.
- For
nitrogen use an 8-580 or IL-580 regulator. For carbon dioxide,
use an 8-320 or IL-320 regulator.
- Set
the regulator to 40 psi. Open all valves and inject gas
into the silo.
Depending
on the quantity and quality of silage remaining, the silo
may need to be emptied after the fire cools. With a small
amount of poor quality silage, the fire may re-ignite after
the carbon dioxide or nitrogen escapes. Fire is not likely
to restart if a large amount of good quality silage remains.
In any event, do not refill the silo until the silo has been
inspected and any repairs made.
- If
safe to do so, unload spoiled or damaged feed and dispose
of in an appropriate manner. Spreading in a safe area (such
as a plowed field) with a manure spreader is one possibility.
- Inspect
the silo for damage which may have caused the fire or which
may be a result of the fire.
- If
structural damage is suspected, have the manufacturer or
dealer inspect the silo and follow their recommendations.
Damaged bottom unloading silos could collapse during emptying
unless strengthened first. Heavily damaged silos may have
to be replaced.
- Follow
steps to insure that the forage system is managed properly
to prevent future silo fires.
Unload the damaged silage because:
- Overheated
silage loses its nutritional value.
- Silage
wetted during fire control measures will spoil.
- Any
missed hot spots may ignite and burning areas not cooled
sufficiently may reignite.
Silage that has been heated above 15O°F loses much of its
nutritional damage. Any charred silage will have very little
feeding damage. Smoke which permeates the feed will affect its
aroma and taste. Cows may or may not eat heat or smoke damaged
silage. The only way to determine the quality of silage is to
have it tested. Contact your county Extension agent for information
about forage testing.
Silage
below the fire level probably will not be damaged and will
not have lost any nutritional value.
Silage saturated with water will mold and spoil because much
of the preserving acids produced during fermentation are leached
out. Nutritional value of saturated silage is reduced and cows
may refuse to eat it.
It is possible to completely extinguish conventional silo fires,
but it is also possible to miss some hot spots. If hot spots
are missed or only partially cooled, they can dry out and ignite.
Injecting water tends to loosen silage fibers and create air
spaces within the silage. If the hot spot is only partially
cooled, the extra air may help re-ignite the fire.
As layers of silage are removed, take additional temperature
readings and examine the silage to determine its condition.
In most cases, it has been necessary to unload silage to just
below the unloading door that has burned through. Unloading
below this level is necessary if there are hot spots, heat damaged
silage or water damaged silage.
Most
unloaders are not intended for continuous operation and the
motors will overheat unless allowed to cool every half hour.
As silage is removed, exposing hot silage could cause a fire
as well. While the unloader motor is cooling, probe for hot
spots and inject water as needed.
In most silo fires there is little, if any, structural damage.
If the fire is allowed to rage out of control it is possible
the concrete may crack, but this is usually not the case. Slow
burning fires seldom damage concrete, but may damage the inside
coating or lining.
Applying
a water fog to the outside of a silo is not recommended by
silo manufacturers. This practice causes more structural stress
than natural cooling. The result could be more damage than
doing nothing at all. It is said that there is no danger of
structural collapse even when small areas of the silo become
so overheated that they glow. Always inspect a silo and repair
damage after any silo fire. The silo dealer or manufacturer
and your insurance agent can provide assistance.
There is some question whether a fire outside the silo can ignite
silage. This can happen with large, hot fires or if sparks manage
to enter the top of the silo and ignite any dry material. Outside
heat is not readily transferred to the silage inside. In many
instances a silo and the silage can be saved, even though an
adjacent barn is a total loss.
Table
4. Silo Capacity Chart |
Size |
Cu.
Ft. |
Dry
Matter |
Approximate
Tons |
Silage
50% Moisture |
Silage
65% Moisture |
12
x 30 |
3390 |
21 |
42 |
60 |
12
x 40 |
4520 |
31 |
62 |
88 |
12
x 50 |
5650 |
42 |
84 |
121 |
14
x 30 |
4620 |
29 |
58 |
82 |
14
x 40 |
6160 |
43 |
86 |
123 |
14
x 50 |
7700 |
60 |
120 |
171 |
14
x 55 |
8464 |
70 |
140 |
201 |
16
x 30 |
6030 |
38 |
76 |
109 |
16
x 40 |
8040 |
56 |
112 |
161 |
16
x 50 |
10050 |
76 |
152 |
218 |
16
x 60 |
12060 |
101 |
202 |
288 |
18
x 40 |
10160 |
72 |
144 |
206 |
18
x 50 |
12700 |
96 |
192 |
274 |
18
x 60 |
15240 |
128 |
256 |
365 |
18
x 65 |
147 |
294 |
421 |
|
18
x 70 |
17780 |
161 |
322 |
459 |
20
x 40 |
12560 |
90 |
180 |
256 |
20
x 50 |
15700 |
118 |
236 |
339 |
20
x 60 |
18840 |
158 |
316 |
452 |
20
x 65 |
20410 |
183 |
366 |
523 |
20
x 70 |
21980 |
199 |
398 |
568 |
20
x 80 |
25120 |
245 |
490 |
700 |
22
x 40 |
15200 |
109 |
218 |
312 |
22
x 50 |
19000 |
151 |
302 |
433 |
22
x 60 |
22800 |
192 |
384 |
549 |
22
x 70 |
36600 |
241 |
482 |
690 |
22
x 80 |
30400 |
299 |
598 |
853 |
24
x 50 |
22600 |
174 |
348 |
497 |
24
x 60 |
27120 |
228 |
456 |
651 |
24
x 70 |
31640 |
288 |
576 |
823 |
24
x 80 |
36160 |
360 |
720 |
1027 |
26
x 50 |
26500 |
206 |
412 |
590 |
26
x 60 |
31800 |
270 |
540 |
771 |
26
x 70 |
37100 |
339 |
678 |
969 |
26
x 80 |
42400 |
429 |
858 |
1226 |
30
x 50 |
35300 |
270 |
540 |
771 |
30
x 60 |
42360 |
363 |
726 |
1037 |
30
x 70 |
49420 |
470 |
941 |
1344 |
30
x 80 |
56480 |
594 |
1188 |
1697 |
30
x 90 |
63540 |
771 |
1542 |
2203 |
36
x 60 |
61020 |
533 |
1066 |
1522 |
36
x 70 |
71190 |
686 |
1373 |
1961 |
36
x 80 |
81360 |
891 |
1782 |
2546 |
36
x 90 |
91530 |
1041 |
2082 |
2974 |
40
x 60 |
75360 |
679 |
1358 |
1939 |
40
x 70 |
87920 |
859 |
1718 |
2455 |
40
x 80 |
100480 |
1108 |
2216 |
3165 |
40
x 90 |
113040 |
1301 |
2602 |
3717 |
- Arble,
William. 1987. Personal letter; Pennsylvania State University,
Agricultural Engineering Building, University Park, PA 16802.
- ASAE
Standard D252.1. 1986. Tower Silos: Unit Weight of Silage
and Silo Capacities; ASAE Standards 1986, American Society
of Agricultural Engineers, 2950 Niles Rd., St. Joseph, MI
49085.
- Bruhn,
H. D. and Koegel, R. G. 1985. You Can Avoid Silage and Haymow
Fires; Hoard's Dairyman, June 10, 1985; pg. 653.
- Midwest
Plan Service, Structures and Environment Handbook, MWPS-1.
Tenth Edition, 1980. Midwest Plan Service, Iowa State University,
Ames, IA 50011, pg 11.
- Murphy,
Dennis and Arble, William. 1986. Extinguishing Silo Fires;
NRAES-18; Northeast Regional Agricultural Engineering Service,
Riley Robb Hall, Cornell University, Ithaca, NY 14853.
- Murphy,
Dennis and Arble, William. 1982. Here's a New Way to Tackle
Silo Fires; Hoard's Dairymen, June 25, 1982, pg 858.
- NIOSH
Alert: Preventing Fatalities Due to Fires and Explosions
in Oxygen-Limited Silos. 1986. DHHS (NIOSH) Publication
No. 86-118; National Institute for Occupational Safety and
Health, 4676 Columbia Parkway, Cincinnati, OH 45226. OH
45226.
- Professional
Design Supplement to the MWPS Structures and Environment
Handbook, MWPS-17, Fifth Edition. 1978. Midwest Plan Service,
Iowa State University, Ames, IA 50011, pp 62-66.
- Silo
Operator's Manual. 1972. International Silo Association,
Inc. (formerly National Silo Association, Inc.), 1163 E.
Ogden, Suite 705-359, Napierville, IL 60540.
Silo
Capacity Chart
The amount
of dry matter a silo holds depends somewhat on the kind of feed
but more on fineness of chop, type of distribution and speed
with which it is filled. For this reason, we have determined
the average dry matter capacity of most size silos finely chopped
and well distributed, with a given dry matter for a given size
silo (see Table 4). The total tonnage in the silo depends largely
on the moisture content.
For
capacity at a different moisture content, use the following
formula:
Example:
How
may tons of 60% moisture silage in 24' x 60' silo?
SOURCE:
Silo Operator's Manual
The following manufacturers are known to be currently active
in Tennessee (as of Feb. 1, 1988). Several companies with structures
in Tennessee have gone out of the silo business.
After
any silo fire or other occurrence which may cause damage to
the silo, such as a lightning strike, contact the manufacturer
and your insurance agent for assistance.
- Monteagle
Silo Company, Inc.
Post Office Box 798
Monteagle, Tennessee 37356-0798
615-924-2241
(concrete stave silos)
Memphis Concrete Silo
Post Office Box 12636
Memphis, Tennessee 38112
901-452-5416
(concrete stave silos)
Mast-Lepley Silo Company, Inc.
10641 Highway 36
Covington, Georgia 30209
ATTN: Sam Hay, Jr.
404-786-3031
Clay and Lambert Mfg.
Highway 146 and 393 at 1-71
Buckner, Kentucky 40010
502-222-1411
(galvanized steel silos and a high-moisture grain bin
sometimes used as an oxygen-limiting silo; makers of Herd
King silos)
Dye Enterprises
855 Snowdoun Chambers Road
Montgomery, Alabama 36105
205-288-5348
(concrete stave silos)
George W. Whitesides Company, Inc.
3048 Muhammad Ali Boulevard
Louisville, Kentucky 40212
502-778-4493
(does not build silos, but manufactures silo coatings)
International Silo Association, Inc.
1163 E. Ogden
Suite 705-359
Napierville, Illinois 60540
312-369-4120
(industry association; source of information)
Disclaimer
and Reproduction Information: Information in NASD does not
represent NIOSH policy. Information included in NASD appears
by permission of the author and/or copyright holder. More
NASD Review: 04/2002
This
document is
PB1307
,
a series of the Agricultural Engineering Department, University
of Tennessee Agricultural Extension Service, Knoxville, Tennessee
37901. Publication date: October 1988.
Timothy
G. Prather, Extension Assistant, Agricultural Engineering
Department, University of Tennessee Agricultural Extension
Service, Knoxville, Tennessee 37901
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