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originally posted by: Salander
originally posted by: completion1
a reply to: Spacespider
"never find out" or "never accept"?
Bingo! The role of cognitive dissonance in how some see 911 cannot be denied.
Firemen reported seeing “molten steel” running in the rubble like “lava in a volcano.
i mean, there are even thermal photos by the NASA (EarthData).
Chapter 5 - Earth pits for charcoal making
Using earth as a shield against oxygen and to insulate the carbonising wood against excessive loss of heat is the oldest system of carbonization and surely goes back to the dawn of history.
For example, such proposed methods for demolishing concrete structures include: an impact demolition method using hammers and chisels, impact breakers, steel balls, or the like; a mechanical demolition method using lock jacks, crushers, cutters, drills, or the like; a thermite demolition method using metallic-wire thermite, thermite moldings (refer to Japanese Patent Application Laid-Open No. 48-67414), or the like; a flame demolition method using jet flame or the like; an explosive demolition method; a gas expansion demolition method; an electrical demolition method using arc discharge, laser, plasma arc (refer to Japanese Patent Application Laid-open No. 55-145294), or the like; and a jet demolition method using water jet, sand jet, or the like.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method and an apparatus which can demolish a concrete structure at a high efficiency while preventing a secondary problem due to noise, flying dust and chips, and the like.
According to the present invention, a concrete demolishing method which melts a surface of a concrete structure comprises: generating a plasma arc from the plasma torch of a plasma arc generator, mixing thermite powder with a supply gas for the plasma torch, passing the mixture of thermite powder and supply gas to the plasma arc, directing the plasma arc at the surface of the concrete structure, and controlling the rate of supply of the thermite powder to the plasma arc in response to the operation of the plasma torch, preferably including initiating and stopping the supply of the thermite powder to the plasma arc in a manner coordinated with the initiation and stoppage of the plasma arc, thereby controlling the heat generated by the thermite reaction and melting at least a portion of the surface of the concrete structure.
In addition to mixing the thermite powder with the supply gas for the plasma torch, at least one material selected from the group consisting of agents to control a thermite reaction starting temperature and agents to lower the melting point of concrete can be included as an ingredient of the mixture.
A concrete structure having a thickness of several meters can be immediately melted by this method.
By skillfully combining a plasma arc demolition method, which is compact and easy to carry out under electrical control but which is poor in thermal efficiency when applied to nonconducting concrete, and a thermite demolition method, which provides a large quantity of heat but in which the thermite reaction is difficult to control, their merits not only offset their demerits but synergize each other. Needless to say, an essential feature of both methods, i.e., a reduced occurrence of the secondary problem of noise, flying dust and chips, and the like is maintained intact in the combination.
(1) Agents to control thermite reaction starting temperature
Thermite powder T is basically a mixture of finely-divided metallic aluminum and ferric oxide that, when ignited, produces extremely high temperatures as the result of the union of the aluminum with the oxygen of the oxide. The thermite reaction on the surface of a concrete structure is so intensive that it easily melts concrete and rock with a melting point in the range of about 1200 to about 2500° C. However, the finer the particulate size of the thermite powder T, the more the thermite powder T tends to induce dust explosion at a room temperature. This tendency is stronger than that of iron dust, coal dust, or the like. Hence, from a safety point of view, it is essential to provide means for externally controlling the start and the stop of the thermite reaction. Also, it is desirable to use the thermite powder T itself for controlling the start of the thermite reaction.
In detail, it is desirable that the thermite powder T be admixed with a material such that the occurrence of the thermite reaction be prevented or minimized at temperatures up to 1000° C. To attain this object, in addition to a consideration of the grain size of each ingredient of the thermite powder T and the characteristics of the supply gas G and other factors, an agent to control a thermite reaction starting temperature is added to the thermite powder T in advance. The additional agent or agents can be premixed with the thermite powder T in the hopper 40, or one or more separate feeding mechanisms can be employed for adding the additional agent or agents to the supply gas.
Any suitable temperature controlling agent can be utilized. Suitable temperature controlling agents include the powders of iron, nickel, manganese, carbon, calcium, magnesium, barium, zirconium, copper, and admixtures of any two or more thereof. For securing safety, it is quite important to control the thermite reaction starting temperature by studying the temperature controlling agents and their grain size and compounding ratios, the characteristics of the supply gas G and others so that the thermite reaction occurs at a desired temperature.
(2) Agents to lower the melting point of concrete
When melting concrete, the plasma torch can face not only horizontally or upwardly but downwardly in many cases. Molten concrete is high in viscosity, and hence does not naturally flow out of a groove in a generally horizontal surface. When melting concrete with the plasma torch facing downwardly, it is desirable that the plasma torch be equipped with a gas nozzle to blow such molten substance (dross) out of the groove. However, since concrete can contain gravel with a melting point higher than that of the concrete, the gas jetted from the gas nozzle may not be able to blow out both the gravel and the molten concrete. As a consequence, a desired progress of the melting process is difficult to achieve.
In order to blow out such gravel as well as the molten concrete, the viscosity of the molten concrete needs to be low. To attain this object, a substance which lowers the melting point of the concrete when it melts and mixes with molten concrete, is added to the thermite powder T in advance. The additional agent or agents can be premixed with the thermite powder T in the hopper 40, or one or more separate feeding mechanisms can be employed for adding the additional agent or agents to the supply gas G. Such agents to lower the melting point of concrete include aluminum, magnesium, iron, sodium, lead oxide, chlorides like sodium chloride, fluorides like fluorite, and admixtures of any two or more thereof.
What is claimed is:
1. In a thermite igniter/heat source comprising a container holding an internal igniter load, the improvement wherein the container consists essentially of consumable consolidated thermite having a low gas output upon combustion, whereby upon ignition, substantially all of the container and said load is consumed with low gas production.
2. A thermite igniter/heat source of claim 1, wherein the consolidated thermite is a combination of aluminum metal and MnO2, MoO3, CuO, Fe2O3, Fe3O4, PbO2, Cr2O3, WO3, Cu2O, Pb3O4, NiO or a mixture thereof.
3. A thermite igniter/heat source of claim 1, wherein the consolidated thermite is a combination of aluminum metal and CuO, Fe2O3, Fe3O4, Cu2O, NiO or a mixture thereof.
4. A thermite igniter/heat source of claim 1, wherein the consolidated thermite is a combination of aluminum metal and Cu2O.
5. A thermite igniter/heat source of claim 1, wherein the consolidated thermite is a combination of about 11 weight percent of Al and about 89 weight percent of Cu2O.
6. A thermite igniter/heat source of claim 1, wherein the consolidated thermite is prepared by hot pressing thermite powder.
7. A thermite igniter/heat source of claim 1, wherein the smallest dimension of the container is about 250 mils.
8. A thermite igniter/heat source of claim 1, wherein the largest dimension of the container is about 4 inches.
9. A thermite igniter/heat source of claim 1, wherein the container has side walls and a bottom wall and which further comprises,
two electrodes passing through the bottom wall into the inside of the container, and
a fuse inside the container and in contact with the ends of the two electrodes which are inside the container.
10. A thermite igniter/heat source of claim 9, wherein the container has cylindrical side walls and wherein the internal igniter load comprises discrete, compositionally distinct zones.
11. A thermite igniter/heat source of claim 10, wherein said internal igniter load comprises a primer mix in contact with said fuse, a low density thermite mix over said primer mix, a thermal barrier over said low density thermite mix, a burnable barrier over said thermal barrier, and a consolidated thermite charge over said burnable barrier.
12. A thermite igniter/heat source of claim 6, wherein the consolidated thermite is hot-pressed at 460.degree - 500.degree C. and at least 10,000 psi for 15-30 minutes to achieve 80-100% of theoretical maximum density.
John85 said: ↑
What do you believe happened to column 79?
What others here (LT : Metabunk.org) may not tell you is that while the vertical kink in the east penthouse does point to a failure of column 79 it only tells you it failed below the penthouse, not where that failure occurred. Interestingly, the evidence shows the east penthouse only came down into the main building a couple of stories which would indicate that column 79 only failed high in the building. The points of evidence for this are :
1. Daylight can only be observed through the windows of the top story.
2. The shock wave goes top to bottom.
3. Window breakage only occurs from the roof line down 15 stories.
4. There is no exterior column deformation observed on the east side as there would be if lateral support was lost.
5. There is no dust emanating from windows on the east side until the exterior starts coming down and the east penthouse dropped into the building 6 to 7 seconds before that.
(LT : During those 7 seconds, no dust. NIST calculated them in their earliest draft report as 8.3 seconds, by the way)
What this also means is that all 24 core columns were still intact for most of their height after the east penthouse fell. To cause a simultaneous drop of all four walls of the building, as observed, all 24 core columns would have to be pulled nearly simultaneously, starting in the center a fraction of a second earlier.
A reason the east penthouse might have been taken down separately first is that it was eccentrically located in the northeast corner. The screen wall and west penthouse, which also sat on the roof, were located in the center of the 144 foot wide building.
Of course, this situation is a lot more plausible and would explain the observations much better than the Rube Goldberg situation that NIST and some others are trying to feed us. Several years after the release of the NIST WTC 7 report, when the drawings were released, it was found that NIST needed to deceptively ignore, omit, and distort several pertinent structural features to even make it have any plausibility. Their analysis looks and sounds like a classic cover-up, where things don't naturally add up and the situation is then contrived.
Last edited: Dec 10, 2017
Tony Szamboti, Dec 10, 2017. Post #1209
Tony Szamboti : One can see the types of things I am talking about concerning the east penthouse in the below video. It is quite clear in the views seen at about 5:32, 5:50, 8:00, and 9:30, that dust doesn't come out of the broken east side windows on the north face until the exterior starts coming down. This alone says the east side interior did not start collapsing low in the building to cause the east penthouse to fall.
Benthamitemetric's attempts to diminish what I am saying need to be seen from the reality that he is a lawyer and is apparently working for the defense of a guilty party here.
Last edited: Dec 10, 2017
Tony Szamboti, Dec 10, 2017. Post #1212.
Whatever you think of Hulsey's integrity, NIST's errors are errors. The missing sideplates were missing, whoever funded Hulsey's study. The web stiffeners were absent whether or not Hulsey declared his conclusions prematurely. The support plate was incorrectly identified by NIST no matter how many PhDs peer-reviewed it.
Do you recognise the possibility that a government agenda can influence the objectivity of a government agency's scientists, the parameters of their study, and the reliability of their conclusions?
John85, Dec 11, 2017. Post #1216
At the end of the day, no one knows with certainty the exact fire conditions in the building, so it's sufficient to demonstrate the building was vulnerable to progressive collapse in reasonable fire scenarios, which has been done.
Not sure I understand the thermite idea either, because melting a 5 inch thick steel plate that is predominantly in compression is only likely to squish it under extreme circumstances.
Originally posted by: kyleplatinum
A reply to: neutronflux
There is zero evidence of CD.
(1)Synchronicity of the removal of support across the whole width of the building, evidenced by (2)the levelness of the roof-line as it came down, and (3)the suddenness of onset of collapse, and (4)the immediate transition from full support to total free-fall.
(5)Natural collapse resulting in free-fall is simply not plausible. It did not happen. It could not happen. (6)Yet Free-fall did in fact happen.
(7)This means it was not a natural collapse. Forces other than the falling upper section of the building (8)suddenly destroyed and removed the supporting columns for at least eight stories across the entire length and width of the building.
Page 18 : In Fig. 6 we show the data set “C,” the respective theoretical trajectories and their accelerations, and SAE.
Here, SAE is calculated over the first 13 points of the data set “C” and the positions predicted by each theoretical model. We note that the free fall has SAE ~= 2.09 m, on one hand side, and on the other, that SAE for the entire three-zone crush-up model over 25 points (~= 3.82 m) is less than SAE for either of the 0-opposition avalanche models (~= 4.69, 4.94 m).
This finding reaffirms our previous conclusion that Phase I is a free fall for H1 ~28 m and not an avalanche that started somewhere in the building (LT : somewhere at floor thirteen, around column 79, as NIST proposed) and propagated for the same distance.
Page 19/24 : It is a reasonable assumption that the seismic signal is excited by changes in the apparent weight of the building, δw, given by δw=fˆ∆W/(M g), where f is the sampling rate, while ˆ∆ is a difference operator acting on a time series of W collected at the sampling rate.
We believe that W', and in particular its time derivative, can be used in interpretation of the seismic signal of the building’s collapse.
As an attempt to connect the two, brings forth numerous additional complications which need to be properly addressed, we leave this topic to future publications.