US 3331671 A
Description (OCR text may contain errors)
y 13, 1967 w. D. soonwm 3,331,671
APPARATUS FOR TRANSFORMING MATERIALS BY PYROGENIC TECHNIQUES Filed Aug. 19, 1964 5 Sheets-Sheet l INVENTOR. WILLIAM D. GOODWIN ATTOR NEYS July 18. 1967 W. D. GOODWlN APPARATUS FOR TRANSFORMING MATERIALS BY PYROGENIC TECHNIQUES 3 Sheets-Sheet 2 Filed Aug. 19, 1964 INVENTOR. WILLIAM D. GOODWIN BY M WMYQAM AT TOR NEYS July 18, 1967 w. D. eooowm 3,331,671
APPARATUS FOR TRANSFORMING MATERIALS BY PYROGENIC TECHNIQUES Filed Aug. 19, 1964 3 Sheets-Sheet 5 az W5 INVENTOR. WILLIAM D. GOODWI N AT TORN EYS United States Patent 3,331,671 APPARATUS FOR TRANSFORMING MATERIALS 7 BY PYROGENIC TECHNIQUES William D. Goodwin, 445 Bishop St. NW., Atlanta, Ga. 30318 Filed Aug. 19, 1964, Ser. No. 390,568 4 Claims. (CI. 6516) This invention relates to means for changing the physical characteristics of a substance, and is more particularly concerned with a method of, and apparatus for, transforming substances through pyrogenic techniques.
There are numerous occasions on which it is desirable to transform a substance having one physical form to the same substance having a dilterent physical form, and many such substances are most easily transformed by heating them to a temperature such that they can be mechanically changed to another physical form.
The usual problem encountered in the changing of the physical form of a substance is one of handling. Though there are heat sources available to raise a substance to the temperature required for the desired transformation, it is extremely ditficult to manipulate the material at such a temperature, and in a gaseous or liquid state, to get the substance into the desired form.
The present invention overcomes the above mentioned difiiculties by providing a very convenient source of heat that is relatively inexpensive to operate; and, convenient means are provided in conjunction with the heat source to handle the material to be transformed. Various devices may be formed integrally with the apparatus by which the substance is transformed physically as it emanates from the device.
In general terms, the device of the present invention includes a chamber having a plurality of gas ports leading thereinto, and means for feeding the material into the chamber from the end opposite the end having the gas ports. A discharge port is provided between the gas ports and feeding means so the substance that has been raised to the desired temperature can be discharged through the discharge port.
With this apparatus, two different gases are directed into the chamber through the gas ports and the gases are ignited. Material to be transformed is sent into the chamber to he exposed to the heat, and the material will be discharged through the discharge port. The temperature of the chamber can be varied by proper selection of gases, and by the quantity of gas put into the chamber. The temperature to which the material is raised can be varied further by varying the rate at which the material is fed into the chamber.
It will therefore be seen that the present invention provides a very simple and efficient means for transforming various materials from one physical state to another. The apparatus provides a very simple means by which the material can be handled both in its original state, and in the heated, transformed state. The apparatus further provides very simple means for physically manipulating the substance after it has been raised to the desired temperature to change the physical form of the material, and it is such that it can be operated very economically; and, it can be used to transform a wide variety of substances, whether the desired transformation requires that the substance be put into a liquid state or into a vapor state.
These and other features and advantages of the invention will become apparent from consideration of the following specification when taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a longitudinal cross-sectional view of one embodiment of the device;
FIG. 2 is a cross-sectional view of the feeding arrange? ment for the device shown in FIG. 1;
FIG. 3 is a cross-sectional view taken substantially along the line 33 in FIG. 1;
FIG. 4 is a cross-sectional view showing the operation of the discharge port; and,
FIG. 5 is a schematic view showing an operational set-up of the device.
Referring now more particularly to the drawings, and to that embodiment of the invention here chosen by Way of illustration, the device includes a heating unit A, a melting zone B, and a material feed unit C. Basically, heat is produced in the heating unit A and fed into the heating zone B; and, material is fed from the material feeding unit C into the heating zone B. Thus, heat contacts the material within the heating zone B, and the pyrogenic transformation takes place within the heating zone B.
In more detail, the heating unit A includes a mixing and combustion chamber 10 which is substantially cylindrical and has a conical lower end 11 which provides a restriction 12. The upper end of the combustion chamber 10 is closed by a plug 14. The plug 14 has an opening 15 therein to receive a pipe 16, and there is a port 18 leading from the opening 15 into the combustion chamber 10. The outside of the plug 14 has a circumferential groove 19, and a plurality of ports 20 communicates with the groove 19 and with the combustion chamber 10.
Surrounding the plug 14 and the combustion chamber 10, there is a water jacket 21 which is so formed as to close the groove 19 and provide an annular passageway which has a pipe 22 communicating therewith. Below the plug 14, the Water jacket 21 simple encloses the combustion chamber 10; and, there are water pipes 24 and 25 communicating with the inside of the water jacket 21 so water, or other cooling fluid, can be passed therethrough. The lowermost end of the water packet 21 is closed by a wall 26 which has a frustoconical projection 28 at its center, the projection 28 being joined to the conical portion 11 and the restriction 12. The arrangement is such that, from the chamber 10, the cross-sectional area is reduced toward the restriction 12, the restriction 12. having the smallest cross-sectional area; and, the frustoconical projection 28 causes the cross-sectional are to enlarge so that there is a flaring of the passageway toward the heating zone B.
It is convenient to make the plug 14, the combustion chamber 10, the portions 11 and 28, and the wall 26 integrally. Around this piece is a cylindrical member forming the water jacket 21.
It will now be seen that two gases, such as oxygen aind hydrogen, can be introduced through the pipes 16 and 22 respectively; and, the oxygen will pass from the pipe, 16, through the port 18, and into the combustion chamber 19 while the hydrogen will be introduced through the pipe 22, will pass through the ports 20, and into the combustion chamber 10 to be mixed with the oxygen and be combined therewith to produce heat. The combustion will produce pressure within the combustion chamber 10 which will cause a high velocity as gases pass through the restriction 12. It will be understood that the gas of which the greater volume is required will be introduced through the pipe 22 and through the ports 20.
The heating zone B includes a tube 30 that is axially aligned with the frustoconical projection 28 so gases will be passed from the projection 28 directly into the' tube 30. A water jacket 31 encloses the tube 30; and, a conical exit port 32 communicates with the tube 30 and extends outwardly to the outermost edge of the water jacket 31.
Referring to FIG. 3 of the drawings, it will be seen that water pipes 34 and 35 are provided in the water jacket 31, are axially aligned with each other, and lie along a chord of the water jacket 31. The exit port 32 intersects that chord so that exit port 32 is directly in the line of flow of the water or other cooling liquid.
Thus far it will be seen that heated gases enter the tube 30 from the projection 28 of the heating unit A and impinge on material that will be fed into the tube 30 from the opposite end thereof. The gases will impinge on the material, cause a physical change in the material, and be discharged through the exit port 32 because of the high velocity of the gas.
Attention is now directed to FIG. 2 of the drawings which shows the material feeding means C. The feed means C includes a body 40* having a central passageway 41 in the center thereof, and an auger 42 within the passageway 41. A hopper 44 is attached to the side of the body 40 and communicates with the passageway 41 through a channel 45. A drive means 46 is connected to the auger 42 to rotate the auger and feed material from the channel 45 into the tube 35 of the heating zone. The drive means 46 is preferably of variable speed in order to vary the rate of feed of material into the heating zone B.
Operation In operation of the device, two gases will be introduced through the pipes 16 and 22 to pass through ports 18 and 20 respectively, thence into the combustion chamber 10. The two gases can be substantially any two gases that will combine and produce heat: natural gas and oxylike. The gases would be introduced under pressure to be mixed and combined within the combustion chamber and, expansion due to the heating would force the gases through the restriction 12 and into the tube 30 of the heating zone B. Since the gases within the combustion chamber 10 are rapidly expanding, the restriction 12 tends to hold back the gases and allow a greater pressure to build up, which produces a higher velocity of gas passing through the restriction 12, into the projection 28 and into the tube 30'.
Many variations can be made with the device to produce the desired temperature and amount of heat required for the particular operation for which the device is to be used. Of course the maximum temperature obtainable with two particular gases would be the temperature of reaction when the gases are mixed in stoichiometric proportions; however, even with stoichiometrically mixed gases, the temperature within the combustion chamber :10 can be varied by varying the quantity of gas that enters the combustion chamber 10. Since heat will be dissipated to the coolant that passes within the jacket 21, if a relatively small quantity of heat is produced Within the combustion chamber 10*, a relatively large percentage of that heat will be carried off by the cooling fluid, thus keeping the temperature of the combustion chamber 10 lower than the temperature of reaction of the gases involved.- Also, a diluent can be used with the gas so that, even when the two active gases are mixed in stoichiometric proportions; the diluent will absorb part of-the heat produced, thereby keeping the temperature of the combustion chamber relatively low. Of course it would be possible to use one of the active gases as the diluent, though it may be undesirable due to the possibility of the gas reacting with the material to be transformed. It will thus be seen that, through proper selection of gases, and the quantity of gases, the temperature within the combustion chamber 10 can be adjusted to perform the desired transformation of material.
gen, hydrogen and oxygen, acetylene and oxygen, or the The intensity and the quantity of heat required will amount of heat required being a function of the specific heat of the material.
With materials having a high specific heat, more heat must be put into the device to eifect a given rise in temperature of the material; hence, either the quantity.
of heat produced in the combustion chamber 10' must be increased, or the rate of feed of material must be decreased. It may, therefore, be desirable to raise the temperature of the combustion when using materials having a high specific heat, so the heat flow into the material will be faster and yield a higher rate of production.
It is preferable that the material fed into the device be a eutectic. This will assure that the melting temperature is as low as is possible with the particular elements used; also, since a eutectic has a constant chemical composition, it will assure that the final product has consistent qualities.
The material fed into the apparatus can be any one of a great variety of materials such as clay, aluminum oxide (Al- 0 fly ash, or any other material that will under go the desired transformation at the temperatures pos- V proximately 50 percent silicon dioxide (SiO and ap-' proximately 25 percent each of iron oxide (F6203) and aluminum oxide (A1 0 One very useful thing that can be made from the fly ash is fiber.
The apparatus of the present invention is admirably suited for the formation of fibers. Two gases will be mixed Within the combustion chamber 10, the gases being so chosen to provide a temperature in the range of 3500 to 5600 F., depending on the rate of production of fibers desired. With the gases introduced at 400' to 500 psi, and a temperature of 3500 to 5600" F., the velocity of gas at the restriction 12 will :be approximately 30,000 feet per minute. a
With this arrangement, fly ash is fed by the auger 42 into the tube 30 where the gases passing through the restriction 12 will impinge on the fly ash that is within the tube 30, having passed from the opening 41,
Since the hot gases of combustion must pass through the tube 30 to impinge on the fly ash that is in the opposite end of the tube 30, there will be a certain amount of turbulence of the gases that will'cause a residence time of the gases within the tube 30 before the gases pass outwardly through the exit port 32. Also, there is a delay in the expulsion of the melted material from the tube 30. During this residence time of both the hot gases of combustion and the melted material, the material will absorb more heat than is necessary simply to convert the solid material into a liquid. This additional amount of heat that is absorbed by the material is sufficient to lower the viscosity of the material so that very fine fibers can be made. Obviously, if the material has a high viscosity, it will be difiicult to draw it into a fine fiber; but if the'material has iaiglery low viscosity, it can be easily drawn into a very fine The turbulence of gases, and residence time of the gases within the tube 30 provides, a much more eflicient heat transfer from the hot combustion gases to the material;
There will be a certain amount of radiant heat emanating from the combustion chamber 10 through the restriction 12 and to the material that is in the tube 30; there will be conduction of heat through'the various walls of the device and to the material that is in the tube 30, and a large amount of heat transfer by conduction from the gas that is in contact with the material; and, there will be convection currents within the tube 30 due to the gas giving up heat to the material that is in the tube 30. Thus, it will be seen that all three methods of heat transfer are utilized in this device to extract the'maximum amount of heat from the hot combustion gases and transfer it to the solid material.
After the fly ash has been heated sufliciently to cause it to have a very low viscosity so that it will flow very readily, the combustion gases coming from the combustion chamber 10 will pick up the liquid material and carry it out the exit port 32. The fly ash will impinge on the edges of the exit port 32, and will be drawn, or blown, out to make fibers. While the material is held by the edge of the exit port, the hot gases will pass thereover to continue to heat the material and to keep the viscosity low. This double action of blowing out of the material by the gases, and the attenuation by the edge of the exit port, will draw the material out into flbers. Since the entire surface is continuously cooled, if any of the material vaporizes, it will condense on the surfaces and still be attenuated or drawn out, to form the fibers. This action is illustrated in FIG. 4 of the drawings which also shows collecting means for the fibers thus formed.
The collecting means includes a canvas belt 50 riding on pulleys 51 and 52. A doctor blade 54 will remove the fibers from the belt 50 for depositing in a suitable container 55.
FIG. of the drawings shows a set-up to use the apparatus of the present invention. The assembly compris ing the units A, B, C is put together, and the auger 42 is connected to the drive means. A gas supply, here shown as two tanks 60 and 61, will be connected to the inlet pipes 16 and 22, and valve means such as valves 62 and 64 will be in the lines from tanks 60 and 61 to the heating unit A. All of the time the heating unit is operating, Water or other cooling liquid will be passed through the Water jackets 21 and 31 from the pipe 65.
The arrangement provides a very convenient apparatus that can be disposed in any particular fashion to enhance the ease of operation of the device and the collection of fibers that are produced by the device.
Though fly ash has been described herein as one material that can be used with the device to form fibers, the apparatus is in no Way restricted to the use of the fly ash. A great variety of materials will produce satisfactory fibers, depending on the particular characteristics required in the fiber that is formed. The requisites of the material to be used are generally that it should be an inorganic material that will remain a liquid over a wide range of temperatures, and will have a variable viscosity that is high at low temperatures, and is low at high temperatures. Silica is one material that exhibits this property; therefore, a material with about 25 percent silica will generally work quite well. Also, it is important to select a material that will not vaporize at the temperatures used if the object is to form fibers. Again, silica will do well since it boils above 4500 F.
The same apparatus can be used for numerous other functions that require a relatively high degree of heat. For one example, a material can be fed into the device as previously described for the fly ash, the temperature of the gases being such that the material being fed into the heating zone will be vaporized. The vapor can then be condensed to form crystals. For instance, aluminum oxide (A1 0 can be vaporized and recrystallized to form one of several precious stones, various impurities being added to provide the desired color. Any material that will vaporize at the temperatures possible with the present apparatus can be fed to the device, vaporized and recrystallized.
Another function that can be achieved with the device is to spray metals, e.g. on other metals. A metal powder, or granules of metal, can be fed into the device as previously described, and the metal will be spit from the device in a molten state, and can be sprayed on other materials. One use of such a method would be to build up a worn metal part. Metal that is the same as that of the worn part would be fed into the device, and sprayed on the part. The metal would be at a sufficiently high temperature that the worn part would also be heated, and a true weld would be achieved between the original worn part and the particles sprayed thereon.
Fractional distillation can also be carried out with this device. With the wide variety of temperatures possible with the device, and the ease with which the temperatures are obtained, it would be quite simple to feed in a material that is a mixture of a plurality of materials having different melting points, vaporization points or the like. The temperature can be varied to separate the various components of the mixture of materials.
Also, synthesis of materials can be achieved with the device. Certain materials must be raised to a relatively high temperature in order to combine. A plurality of such materials can be fed into the device, the temperature adjusted to that necessary to initiate an endothermic reaction, and the reaction, or synthesis will take place. If a high temperature is required simply to initiate the reaction, the reaction can be initiated with the device, then the input of heat by the device can be terminated while the reaction continues as an exothermic or isothermic reaction. Of course, if the entire reaction is endothermic, heat will be generated by the device throughout the time of the reaction.
It will thus be seen that the apparatus of the present invention provides very simple and inexpensive means to achieve a wide variety of physical transformations through pyrogenic techniques. The device is very inexpensive both to make and to operate, since readily obtainable gases can be used with the device to produce reasonably high temperatures.
It will thus be seen by those skilled in the art that the particular embodiment of the invention here chosen is by way of illustration only and is meant to be in no Way restrictive; therefore, numerous changes and modifications may be made, and the full use of equivalents resorted to, without departing from the spirit or scope of the invention as outlined in the appended claims.
What is claimed as invention is:
1. Apparatus for pyrogenic transformation of materials having a heating zone, an exit from said heating zone, feeding means for feeding material to said heating zone, means for producing a high-temperature high-velocity gas, means for directing said high-temperature high-velocity gas to said heating zone, said means for producing a hightemperature high-velocity gas including a combustion chamber, means for introducing gas to said combustion chamber, restricting means on said combustion chamber for restricting the outward flow of gas from said combustion chamber, the arrangement being such that material fed into said heating zone will be engaged by said hightemperature high-velocity gas from said combustion chamber, and the material in its pyrogenically changed form will be carried by said high-temperature high-velocity gas through said exit.
2. Apparatus for pyrogenic transformation of materials having a heating zone including a tube, an exit port in said tube extending from the side of said tube, feeding means for feeding material to said tube, means for producing a high-temperature high-velocity gas, means for directing said high-temperature high-velocity gas to said tube of said heating zone, said means for producing a high-temperature high-velocity gas including a combustion chamber, means for introducing gas to said combustion chamber, restricting means on said combustion chamber for restricting the outward flow of gas from said combustion chamber, the arrangement being such that material fed into said tube of said heating zone will be engaged by said high-temperature high-velocity gas from said combustion chamber, and the material in its pyrogenically changed form will be carried by said hightemperature high-velocity gas through said exit port.
3. Apparatus for pyrogenic transformation of materials having a heating zone including a member having an opening therein, an exit port extending from said opening in said member, feeding means for feeding material into said opening in said member, means for producing a high-temperature high-velocity gas, means for directing said high-temperature high-velocity gas to said open- 7 ing in said member, said means for producing a high-temperature high-velocity gas including a combustion chamber, means at one end of said combustion chamber for s introducing gas to said combustion chamber, restricting means at the opposite end of said combustion chamber for restricting the outward flow of gas from said combustion chamber, the arrangement being such that material fed into said opening in said member will be engaged by said high-temperature high-velocity gas from said combustion chamber, and the material in its pyrogenically changed form will be carried by said high-temperature high-velocity gas through said exit port. I
4. Apparatus for pyrogenic transformation of material having a heating zone including a tube, a water jacket surrounding said tube and coaxial therewith, said tube extending completely through said water jacket and being open at each end, an exit port extending from said tube substantially radially thereof and opening outside said water jacket; feeding means for feeding material to said tube in said heating zone; and means for producing a high-temperature high-velocity gas including a combusend of said combustion chamber having restricting means to restrict the flow of gas from said combustion chamber, a water jacket surrounding said combustion chamber, passage means from said combustion chamber to the outside of said water jacket, said passage means being axially aligned and abutting said tube of said heating zone; the arrangement being such that material fed by said feeding means into said tube of said heating zone will be engaged in said heating zone by said high-temperature high-velocity gas from said passage means, and the pyrogenically transformed material will be carried by said high-temperature high-velocity gas through said exit port.
References Cited UNITED STATES PATENTS 468,216 2/1892 Birge 1s 2.5
2,521,830 9/1950 Collins 65 16 2,911,669 11/1959 Beckwith.
3,015,127 1/1962 Stalego 65 5 20 3,055,591 9/1962 Shepard 1s 302 tion chamber, a plug in one end of said combustion chamher, said plug having a plurality of ports therein for introducing gas to said combustion chamber, the opposite DONALL H. SYLVESTER, Primary Examiner. R. L. LINDSAY, Assistant Examiner.