Fluid sprinkling – spraying – and diffusing – Rigid fluid confining distributor – Assembly or disassembly feature
Reexamination Certificate
1999-08-16
2002-06-04
Doerrler, William C. (Department: 3752)
Fluid sprinkling, spraying, and diffusing
Rigid fluid confining distributor
Assembly or disassembly feature
C239S271000, C239S397000, C239S436000, C239S530000, C239S543000, C239S544000, C239S556000, C239S559000, C239S567000, C239S589000, C169S070000, C285S086000, C285S361000, C285S376000, C285S401000
Reexamination Certificate
active
06398136
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to fire fighting equipment, and particularly to water nozzles adapted to pierce through a roof and provide a water spray to extinguish a fire, and to alternative, exchangeable embodiments that may pierce into other structures.
2. Background Information
Effective fire control and extinguishment requires basic understanding of chemical and physical nature of fire. Combustion is the rapid oxidation of fuel along with the evolution of heat and light. The “fire triangle” includes oxygen, heat and fuel; fire needs approximately 16% oxygen to free burn.
In its starting or “incipient phase,” fire may produce flame temperatures of 1000 degrees Fahrenheit, yet the room temperature is only slightly increased. Water vapor, carbon dioxide and small quantity of sulfur dioxide and carbon monoxide are present.
The second phase of fire is referred to as free burning; this encompasses all free burning activities of the fire. Oxygen rich air is drawn into the fire and convection heat carries gases into the uppermost regions of the room. The heated gases then spread out laterally from the upper most surfaces forcing the cooler air downward. Along its path fire is consuming all combustible materials and temperatures of approximately 1300 degrees Fahrenheit are consuming oxygen and will continue to burn until there is insufficient oxygen to react with the fuel load.
The third phase of fire, referred to as smoldering, occurs when the burning is reduced to glowing embers. If the room is sufficiently airtight and the oxygen has been reduced, temperatures will rise and smoke will fill the room along with increased hydrogen and methane gas which leads to the possibility of backdraft (a new entry of oxygen).
Early theories of fire fighting, often held even now by lay persons, were that the fire was to be “drowned,” i.e., deprived of oxygen. The continuing development of the art, however, along with the contributions of physics and chemistry, have shown that the principal effect of applying fluids such as water to a fire lie in reducing the temperature below that at which burning will occur. That must occur, of course, by the transfer of heat energy from the burning materials to the water.
The processes by which water or similar such fire-fighting materials absorb heat are actually three in number: firstly, the water is heated up from its “hose temperature” to the boiling point; secondly, that heated water is vaporized into water vapor; and thirdly that water vapor is itself heated further, so long as the temperature of the fire remains above about 212 degrees Fahrenheit, the boiling point of water. It is the second one of those steps that is most effective in absorbing heat from a fire, as can be seen from a comparison of the number of calories or BTUs of heat required to accomplish each step.
Thus, the specific heat of water, by which is meant the amount of heat that is required to raise the temperature of a gram of water one degree Centigrade is approximately 1 calorie. The latent heat of vaporization of water, however, is 540 calories per gram. Since one BTU is equivalent to 252 calories, one gram of water can remove somewhat more than 2 BTU of heat from a fire by its vaporization alone. In more familiar firefighting terms, since a gallon of water weighs roughly 3.8 kilograms, vaporization of a gallon of water absorbs about 7,600 BTUs of heat.
The subsequent heating of the resultant water vapor is not inconsequential, given that the burning materials and hot gases may be 1000 degrees or so above room temperature, the object being, of course, that upon heating the water vapor the other materials will cool down below their ignition temperature and the fire will be extinguished. However, it is the initial vaporization of the incident water that makes the heating of the resultant water vapor possible, hence efficient water vaporization turns out to be the key step in effective fire-fighting.
The so-called “expansion” of an amount of water into vapor is often referred to as being effective in “smothering” a fire because that water vapor occupies space that might otherwise be occupied by oxygen. That idea, however, neglects the fact that even though the theoretical volume of an amount of water in the vapor state is about 1700 times that in its liquid state, one still has precisely the same amount of water, every molecule of water takes up roughly the same volume as it did in its liquid state, and since that water vapor now constitutes a gas, that theoretical volume consists primarily of empty space if the water vapor were there alone, or space that in the context of a fire will be filled with other gases, including both oxygen and the hot gases of the fire, such as the fire byproducts carbon monoxide and carbon dioxide. The effect of the dispersal of an amount of water into vapor derives not from any volume change, therefore, but rather because the wide dispersal of the water vapor puts it into intimate contact with the gases that are to be cooled off, and the same will of course be true of a mist of visible water droplets (which near the boiling point constitutes steam), and those droplets may then be vaporized into invisible water vapor to provide the most effective step in fire fighting.
Firefighters responding to a confined fire that is in either the free-burning or smoldering phases risk the occurrence of backdraft by ventilating the structure. The fire is incomplete because it has used up all available oxygen, yet heat has remained in the structure. Improper ventilation will increase oxygen which will then explode upon reaching the stalled combustion process. The proper use of the piercing nozzle and attachments will avoid opening up a new source of oxygen to remove one side of the fire triangle oxygen, and then by cooling the fire can be removed from its existing, dangerous state to one of extinguishment.
With respect to the cooling effects of mist, a test was conducted on one version of the mist-producing, penetrating nozzle to be described hereinafter, with reference to a standard fire nozzle that ejects liquid water. In a test building, fires were initiated in rooms of comparable size so as to become totally involved. Using a standard fire nozzle, the first of such fires was extinguished in 2 minutes using 250 gallons of water. The second fire was extinguished using the misting nozzle in 5 seconds using 15 gallons of water.
Generally representative of prior art penetrating nozzles is the “FAAAST” tool
10
manufactured and sold by Advanced Manufacturing Technologies, Inc. of Grafton, Wis. and shown in FIG.
1
. Tool
10
generally comprises an elongate cylindrical and fluid-carrying shaft
12
, at a first end of which is disposed a fluid discharge region
14
and distally therefrom a penetrating member
16
. At a second end of shaft
12
is disposed firstly a nozzle connector
18
to which is attached a fluid-bearing fire hose (not shown), and secondly a guide shaft
20
for effecting orientation of tool
10
relative to a roof or like structure to be penetrated. Included on guide shaft
20
is a slide hammer
22
that can be used to assist in forcing the penetrating member
16
through a roof or the like. Particular nozzle tip designs can be seen in U.S. Des. 339,846 issued Sep. 28, 1993 to Magee and U.S. Des. 351,642 issued Oct. 18, 1994 to Mitchell.
Beyond such design considerations, some particular functional aspects of nozzle construction have been set out in U.S. Pat. No. 4,358,058 issued is Nov. 9, 1982 to Bierman, U.S. Pat. No. 4,700,894 issued Oct. 20, 1987 to Grzych, and U.S. Pat. No. 4,568,025 issued Feb. 4, 1986 to McLoud. The Bierman device includes a rotating section and control handle whereby an operator can select among modes of operation involving a whirling wide angle cone of fog, a forward narrow angle cone of fog, a solid stream, or shutoff. The Grzych device provides an essentially spherical stream of fog so as to encompass the entire interior of a room, thus also eliminating reactive forces that can
Doerrler William C.
Jade S. Rose
Kim Christopher S.
Lovell William S.
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