Patent Grant
7341112
Not applicable.
Not applicable.
This application relates generally to firefighting training fluids. More particularly, the application relates to a blend of paraffins that is an improved firefighting training fluid, and a method of making and using said blend. When burned, the firefighting training fluid provides reduced emissions of particulates and volatile organic compounds, while closely imitating the types of fires needed for firefighting training.
Paraffins, also commonly known as alkanes, are one of the many components of petroleum. They are members of the homologous series of saturated hydrocarbons of the general molecular form CnH2n+2. Paraffins may be straight chains or branched (e.g., isoparaffins). Examples of the series of compounds of this form are methane (CH4), ethane (C2H6), propane (C3H8), and butane (C4H10). Paraffins of various sizes (according to the number of carbon atoms, e.g., C2, C3, C4, and so on) are commonly separated from one another via distillation according to their various boiling points, where higher boiling points generally correspond to heavier paraffins. For example, under similar conditions, decane (C10H22) possesses a higher boiling point than pentane (C5H12). This relationship is also highlighted by the fact that, under similar conditions, paraffins include gases, liquids, and waxy solids. The gases are the lighter compounds, such as methane (C1) and propane (C3), the liquids are heavier than the gases (e.g., C8), and the waxy solids are yet heavier than the liquids. Similarly, the lighter paraffins generally possess lower flash points and boiling points, and higher vapor pressures, than the heavier compounds. As for their practical applications, paraffins are commonly used in charcoal starters, copier fluids, aviation and automotive fuels, lamp oils, solvents for insecticides and polishes, and camping fuels.
Firefighting training fluids (“FFTF”) are combustible compounds used in training of firefighters. FFTFs are ignited in various situations to simulate accidental fires that would be encountered in both industrial and domestic environments. Common gasoline and/or diesel fuels, for example, may be used as FFTFs. However, burning such diesel fuels creates significant amounts of pollutants in the form of soot or smoke, and related particulates and volatile organic compounds. In addition, burning gasoline and/or diesel fuels leaves a residue that must be discarded as a hazardous waste, and any fuel that is not burned is often not reusable and also creates hazardous waste.
The various circumstances under which accidental fires occur often make it difficult to accurately replicate a particular type of fire for training purposes. This is true because of the wide range of combustibles that fuel accidental fires, and the wide range of structures in and around which the fires occur. For example, the fire fuel, props, and extinguishing techniques needed to duplicate and extinguish an accidental flange fire involving the leak of a light chemical at an industrial plant may be very different from the fire fuel, props, and extinguishing techniques needed to duplicate and extinguish a fire at a fuel storage warehouse. Typically, existing FFTFs are heavier compounds that possess higher boiling points and that, when burned, do not accurately simulate the types of fires associated with burning of lighter chemicals, such as the gases or solvents often involved in industrial fires. Thus, a need exists for improved, environmentally friendly FFTFs that accurately simulate a variety of fires.
In an embodiment, an FFTF comprising a blend of paraffins is disclosed. The overall FFTF composition as well as the individual blend components used to create the FFTF comprise paraffins in the range possessing from about two to about twelve carbon atoms. The FFTFs may have Reid vapor pressures in the range from about 2 to about 6.5 pounds per square inch. The FFTFs also may have an initial boiling point of not less than about 80 degrees Fahrenheit and an end boiling point of not more than about 370 degrees Fahrenheit. The FFTFs burn relatively cleanly and keep emissions of volatile organic compounds, compounds containing sulfur, smoke, particulates, olefins, and aromatics to a minimum. The blend components mixed to create the blends of paraffins may be controlled in order to maintain Reid vapor pressure and initial and end boiling points of the FFTF. Oxygenates may be added to FFTFs in order to further reduce smoke emissions.
In an embodiment, the blend components are blended in specific proportions in order to make an FFTF having desired burn characteristics, taking into account, for example, burn application and weather. Oxygenates may be added to the FFTF to make it more combustible. The FFTF may be dispensed and ignited in the desired firefighting training scenario. The blend may be heavier or lighter depending on the particular training application.
An FFTF blend in accordance with the present invention comprises a mixture of one or more blend components, where each blend component may have the same or a different composition. The blend components contain the ingredients (e.g., paraffin compounds such as isopentane, hexane, heptane, octane, etc.) that ultimately make up the blend. The blend components comprise one or more paraffins having from two to twelve carbon atoms (C2 to C12). In an embodiment, an isopentane blend component comprises at least about 95 weight percent isopentane (C5). In another embodiment, a heavy paraffin blend component comprises at least about 55 weight percent decane (C10). In another embodiment, a light paraffin blend component comprises at least about 80 weight percent octane (C8). In yet another embodiment, an alkylate blend component comprises at least about 50 weight percent octane (C8).
The blend components comprising the FFTF blends of the present invention may have different sources. For example, in one embodiment a heavy paraffin blend component and a light paraffin blend component are different cuts from a petroleum refinery distillation column. In another embodiment, an alkylate blend component is from a hydrofluoric acid alkylation unit. In yet another embodiment, an isopentane blend component is from an isomerization unit. Any number and combination of blend components, each from a different source, may be mixed to create a desired FFTF. In an embodiment, a blend comprises two paraffin blend components, for example the heavy paraffin blend component and the light paraffin blend component. In another embodiment, a blend comprises three blend components, for example the heavy paraffin blend component, the light paraffin blend component, and an oxygenate, such as ethyl tertiary butyl ether, or ethanol. The various blend components that make up a particular blend are typically prepared by admixing the components simultaneously or in sequence in a container, such as a transportation or storage tank.
The FFTFs comprise, or alternatively consist essentially of, a blend of paraffins having no less than about 2 carbon atoms and no more than about 12 carbon atoms, alternatively having no less than about 4 carbon atoms and no more than about 12 carbon atoms, and alternatively having no less than about 5 carbon atoms and no more than about 11 carbon atoms. In an embodiment, an FFTF comprises at least about 1 weight percent isopentane, alternatively at least about 5 weight percent isopentane, alternatively at least about 10 weight percent isopentane, alternatively at least about 15 weight percent isopentane, and alternatively at least about 20 weight percent isopentane. In an embodiment, the FFTF is a blend of paraffins comprising, or alternatively consisting essentially of, less than about 0.1 weight percent C3; less than about 0.5 weight percent C4; from about 1.0 to about 20 weight percent C5; from about 0.5 to about 1.5 weight percent C6; from about 1.5 to about 6.5 weight percent C7; from about 19 to about 35 weight percent C8; from about 6 to about 11 weight percent C9; from about 28 to about 44 weight percent CIO; from about 9 to about 14 weight percent C11; less than about 0.1 weight percent C12; less than about 1.0 weight percent miscellaneous compounds, based on the total weight of the blend.
The Reid vapor pressure (RVP) is the vapor pressure measured according to ASTM D-323. Generally, the Reid vapor pressure of an FFTF blend herein may be adjusted up or down, depending on the time of year, geographic location, and particular firefighting training application for which a blend will be employed. The RVP may be adjusted up or down by manipulating the relative amounts of heavier and lighter paraffins in a blend. For example, pentane (C5) is lighter than, and possesses a higher RVP than, decane (C10). Thus, the RVP of a paraffin blend may generally be adjusted up or down by increasing the percentage of lighter or heavier paraffins, respectively, in the blend. The RVP may be adjusted depending on the desired burn characteristics that are to be mimicked. For example, a fire associated with the burning of a heavy fluid, such as a jet fuel, may possess different burn characteristics than a fire associated with a lighter fluid, such as a solvent fire in an industrial plant. Thus, the RVP may be adjusted up or down by manipulating the relative amounts of heavier and lighter paraffins, depending on the firefighting training application.
In an embodiment of FFTF blends, the relative amounts of blend components may be adjusted to achieve Reid vapor pressures from about 2 to about 6.5 pounds per square inch (psi), depending on the time of year, geographic location, and application. In an embodiment, the RVP is no less than about 2 psi, alternatively no less than about 2.5 psi, and alternatively no less than about 3 psi. In another embodiment where the season is winter, the RVP may be controlled in the range from about 5.5 to about 6.5 psi. In yet another embodiment where the season is summer, the RVP may be controlled in the range from about 2 to about 3 psi. In still another embodiment, the RVP may be controlled in the range from about 4 to about 5 psi. The time of year is considered because the RVP moves up or down with temperature. Thus, for the same training application, it is generally necessary to increase the RVP in winter and decrease the RVP in summer in order to achieve similar burn characteristics in both seasons based on the schedule of seasonal and geographical volatility classes presented in ASTM D-4814 with modified Vapor Pressure Classes specific to the paraffin blends described herein.
Boiling point is another characteristic to be considered with the paraffin blends of the present invention. Generally, lighter paraffins possess lower boiling points, and correspondingly lower ignition temperatures. As the percentage of heavier carbon compounds in a blend increases, so do the boiling point and ignition temperatures. As with RVP, the boiling points of the blends are controlled depending on the type of burn to be mimicked and season of the year. In an embodiment, the boiling range of the paraffin blend components is from about 80 degrees Fahrenheit to no more than about 370 degrees Fahrenheit. In another embodiment, the boiling range is from about 100 degrees Fahrenheit to about 370 degrees Fahrenheit.
In an embodiment involving cooler temperatures and/or duplication of a burn of lighter chemicals, the RVP may be adjusted to be in the range of from about 5.5 to about 6.5, while the same circumstantial considerations would cause the initial boiling point of a blend to be about 80 to 110 degrees Fahrenheit, alternatively about 100 to 110 degrees Fahrenheit. In contrast, in an embodiment involving warmer temperatures and/or duplication of a burn of heavier chemicals, the RVP may be adjusted to be in the range of from about 2 to about 3, while the initial boiling point of the blend would be from about 110 to 150 degrees Fahrenheit.
Generally, as long as the boiling point and RVP of the blend are controlled, the overall composition of the blend and/or the composition of the individual paraffin blend components may vary. For example, in an embodiment, an FFTF blend comprises a heavy paraffin blend component that is at least about 55 weight percent decane, and a light paraffin blend component comprising at least about 80 weight percent octane. The paraffin blend of this embodiment comprises no more than about 60 liquid volume percent of the heavy paraffin blend component, and no less than about 40 liquid volume percent of the light paraffin blend component. The resulting RVP is in the range of 2 to 3 psi and the initial boiling point is from about 110 to 150 degrees Fahrenheit.
In another embodiment, an FFTF includes a heavy paraffin blend component comprising at least about 55 weight percent decane, an isopentane blend component comprising at least about 95 weight percent isopentane, an alkylate blend component comprising at least about 50 weight percent octane, and a light paraffin blend component comprising at least about 80 weight percent octane. The paraffin blend of this embodiment comprises from at least about 50 to about 80 liquid volume percent of the heavy paraffin blend component, from 0 to about 10 liquid volume percent of the light paraffin blend component, from 1 to about 5 liquid volume percent of the isopentane blend component, and from at least about 10 to about 40 liquid volume percent of the alkylate blend component. The resulting RVP of this embodiment may also be in the range of 2 to 3 psi and the initial boiling point is from about 110 to 150 degrees Fahrenheit.
In another embodiment, an FFTF comprises no less than about 15 liquid volume percent of a heavy paraffin blend component comprising at least 55 weight percent decane, and no more than about 85 liquid volume percent of a light paraffin blend component comprising is at least about 80 weight percent octane.
In another embodiment, an FFTF comprises at least about 5 to about 30 liquid volume percent of an isopentane blend component that comprises at least 95 weight percent isopentane, at least about 35 to about 60 liquid volume percent of a heavy paraffin blend component that comprises at least 55 weight percent decane, and at least about 30 to about 45 liquid volume percent of a light paraffin blend component that comprises at least about 80 weight percent octane.
In another embodiment, an FFTF comprises at least about 40 to about 70 liquid volume percent of a heavy paraffin blend component that comprises at least 55 weight percent decane, from 0 to about 20 liquid volume percent of an isopentane blend component that comprises at least 95 weight percent isopentane, and from at least about 25 to about 45 liquid volume percent of an alkylate blend component that comprises at least about 50 weight percent octane.
Adding one or more oxygenates as a blend component of an FFTF blend further reduces emissions generated by a burn. The oxygenates add oxygen to the blend, which increases the combustibility of the blend, thereby reducing emissions. Oxygenates may be added to any FFTF composition or blend, for example the paraffin blends described herein. Generally, oxygenates are selected because their boiling points are about equal to or below the boiling points of the FFTF. Also, certain oxygenates have low water solubility, which makes putting out the fires and cleanup easier. The amount of oxygenates added corresponds to a weight percent oxygen added to the blend. In an embodiment, oxygenates comprise no less than about 5 and no more than about 50 liquid volume percent of a blend. In another embodiment, oxygenates comprise no less than about 10 and no more than about 30 liquid volume percent of a blend.
The oxygen content in a blend provided by oxygenates typically comprises no more than about 6 weight percent and no less than about 0.5 weight percent. In an embodiment, the oxygen content provided to a blend by oxygenates comprises no more than about 3.5 weight percent and no less than about 1.5 weight percent. In another embodiment, the oxygen content provided to a blend by oxygenates comprises no more than about 2.2 weight percent and no less than about 1.8 weight percent.
Oxygenates may be selected from the class of oxygenates including alcohols, ethers, carboxylic acids, epoxides, and combinations thereof where the selected oxygenates possess boiling points of no less than about 80 degrees Fahrenheit and no more than about 370 degrees Fahrenheit. In an embodiment, the oxygenates may be selected from a group consisting of methyl tertiary butyl ether (MTBE), ethyl tertiary butyl ether (ETBE), ethanol, propyl acetate, butyl acetate, 2-ethoxyethanol, and combinations thereof. In an embodiment, the oxygenates comprise ETBE and/or ethanol and are added to the paraffin blends described herein.
In an embodiment for preparing FFTFs as shown by
The FFTF blends of the present invention may be employed in a variety of firefighting training scenarios. The simplest is the pan burn, wherein the FFTF is poured into a pan containing water. The water serves to protect the concrete and pan from the evolved heat. The blend is ignited and such a pan burn is a common exercise for fire extinguisher training. Other training may involve the use of other props such as loading racks for railcars, flanges, pumps, airplanes, etc. In some of the scenarios, the fuel pours or squirts out of a hole in a piece of equipment. Flange fires are generally more difficult to extinguish when the burning fluid is lighter because the fire crawls up the fuel to the source of the leak. If a heavier fuel is used, a separation between the leaking fuel and the fire exists and the fire fighter need only blow the fire off the fuel stream with his or her hose. In this way, the ability of the FFTFs described herein to accurately mimic both lighter and heavier fuel fires allows them to closely duplicate reality.
The blends described herein are also environmentally friendly in that emissions of smoke, particulates, and volatile organic compounds (VOCs) are minimal, and the concentrations of sulfur, aromatic, and olefinic compounds are low. In addition, fewer hazardous wastes are created because the paraffin blends leave significantly less residue than diesel/gasoline mixtures when burned to completion. Plus, with incomplete burns, the remaining fluid may be recycled and reused. The concentration of aromatics in the blends is typically less than about 10 liquid volume percent, and in some embodiments less than about 1 liquid volume percent. Likewise, the concentration of olefins in the blends is typically less than about 10 liquid volume percent, and in some embodiments less than about 1 liquid volume percent. Similarly low is the concentration of sulfur in the blends, which is typically less than 10 parts per million by weight. When burned, the blends typically emit less than about 0.0130 pounds of volatile organic compounds per pound of fluid burned, alternatively less than about 0.010 pounds of volatile organic compounds per pound of fluid burned. In addition, burning the blends typically produces less than about 0.030 pounds of particulate matter per pound of fluid burned.
The invention having been generally described, the following examples are given as particular embodiments of the invention and to demonstrate the practice and advantages thereof. It is understood that the examples are given by way of illustration and are not intended to limit the specification or the claims to follow in any manner.
Examples 1-4 show paraffin blending components suitable for use in FFTFs, and gas chromatogram data for each blending component is listed in Tables 1-4, respectively. Example 1 is an isopentane blend component, Example 2 is a heavy paraffin blend component, Example 3 is a light paraffin blend component, and Example 4 is an alkylate blend component. Table 1 contains the weight percent of each component present in an isopentane blend component.
Table 2 contains the weight percent of each compound present in a heavy paraffin blend component. “C8s” represents the weight percentage of chemical compounds in the blend component having 8 carbon atoms, “C9s” represents the weight percentage of chemical compounds in the blend component having 9 carbon atoms, and so forth.
Table 3 contains the weight percent of each compound present in a light paraffin blend component.
The data in Table 4 gives an example of the weight percent of each compound present in an alkylate blend component.
Example 5 is an FFTF comprising a blend of the heavy, light, and isopentane blend components, as illustrated by Examples 2, 3, and 1, respectively. Data for Example 5 is provided in Table 5.
Example 6 is an FFTF comprising a blend of the heavy and light paraffin blend components, as illustrated by Examples 2 and 3, respectively. Data for Example 6 is provided in Table 6.
Example 7 is an FFTF comprising a blend of the heavy, alkylate, and isopentane blend components, as illustrated by Examples 2, 4, and 1, respectively. Data for Example 7 is provided in Table 7.
Example 8 is an FFTF comprising a blend of the heavy, light, alkylate, and isopentane blend components, as illustrated by Examples 2, 3, 4, and 1, respectively. Data for Example 8 is provided in Table 8.
Example 9 is an FFTF comprising a blend of the heavy, light, and isopentane blend components corresponding to those in Examples 2, 3, and 1, respectively, and oxygenates. In this example, the oxygenate is ethyl tertiary butyl ether (ETBE). Data for Example 9 is provided in Table 9.
Example 10 lists oxygenates and the liquid volume percent of each oxygenate added to an FFTF, for example a paraffin blend as disclosed herein, in order to achieve certain weight percent oxygen levels in the blend. The data for Example 10 is provided in Table 10.
Comparative Example 11 provides a comparison of the combustion products of a paraffin FFTF blend as disclosed herein and an oxygenated paraffin FFTF blend as disclosed herein to those of a conventional 60:40 diesel:gasoline blend. Both volatile organic compounds (VOCs) and particulate matter (soot) were measured quantitatively. A two-fluid-ounce sample of the product under test was poured into the bottom of a flat pan and immediately ignited using a fireplace match. Data was gathered until the flame self-extinguished and no significant volume of volatile organic compound (VOC) was being emitted. For the products tested, the data collection time was approximately three minutes. Volatile organic carbon was measured with a Ratfisch RS55CA total hydrocarbon analyzer with a flame ionization detector. VOCs are reported as methane. Particulate matter was collected on glass fiber filters and the particulate mass was measured by weighing. Data is reported as pound of VOC or particulate per pound of sample fluid. Each product was evaluated in three replicate test runs and the results in Table 11 represent the average of those three runs. As expected, the paraffin blends of the present invention emitted less particulate matter and fewer VOCs than did the conventional 60:40 diesel/gasoline blend. The high burn temperature of the paraffin blends resulted in greater combustion to CO2 and contributed to particulate matter that dissipates readily. Data for Example 11 is provided in Table 11.
While embodiments of the invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit and teachings of the invention. The embodiments described herein are exemplary only, and are not intended to be limiting. Equivalent techniques and ingredients may be substituted for those shown, and other changes can be made within the scope of the present invention as defined by the appended claims. Many variations and modifications of the invention disclosed herein are possible and are within the scope of the invention. Accordingly, the scope of protection is not limited by the description set out above, but is only limited by the claims which follow, that scope including all equivalents of the subject matter of the claims.
This is a Divisional Application of U.S. patent application Ser. No. 10/305,748, filed Nov. 27, 2002 and entitled “Firefighting Training Fluid and Method for Making Same,” which is hereby incorporated by reference herein in its entirety.
| Number | Name | Date | Kind |
|---|---|---|---|
| 3294685 | Stevens et al. | Dec 1966 | A |
| 3341311 | Pedersen | Sep 1967 | A |
| 3644073 | Goldsmith | Feb 1972 | A |
| 4389220 | Kracklauer | Jun 1983 | A |
| 4541835 | Norton et al. | Sep 1985 | A |
| 4908045 | Farrar | Mar 1990 | A |
| 4998876 | Farrar | Mar 1991 | A |
| 5055050 | Rogers et al. | Oct 1991 | A |
| 5411397 | Rogers et al. | May 1995 | A |
| 5713964 | Schreiner et al. | Feb 1998 | A |
| 6458176 | Yeh et al. | Oct 2002 | B2 |
| 6500008 | Ebersole et al. | Dec 2002 | B1 |
| 6858048 | Jimeson et al. | Feb 2005 | B1 |
| Number | Date | Country | |
|---|---|---|---|
| 20060177804 A1 | Aug 2006 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10305748 | Nov 2002 | US |
| Child | 11390756 | US |
