CA1165966A - Process and apparatus for packing granular materials - Google Patents
Process and apparatus for packing granular materialsInfo
- Publication number
- CA1165966A CA1165966A CA000364534A CA364534A CA1165966A CA 1165966 A CA1165966 A CA 1165966A CA 000364534 A CA000364534 A CA 000364534A CA 364534 A CA364534 A CA 364534A CA 1165966 A CA1165966 A CA 1165966A
- Authority
- CA
- Canada
- Prior art keywords
- process according
- mixture
- combustion chamber
- fuel
- exothermic reaction
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C15/00—Moulding machines characterised by the compacting mechanism; Accessories therefor
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Solid Fuels And Fuel-Associated Substances (AREA)
- Pretreatment Of Seeds And Plants (AREA)
- Wrappers (AREA)
- Portable Nailing Machines And Staplers (AREA)
- Casting Devices For Molds (AREA)
- Casting Or Compression Moulding Of Plastics Or The Like (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE:
For packing granular materials, particularly foundry moulding materials, by means of an exothermic reaction of a mixture of air and fuel in a combustion chamber, a relative movement between the combustible mixture and one or more pulse triggers is produced during the exothermic reaction, for example by a blower disposed in the combustion chamber, by means of movable pulse triggers or sequential ignition of a plurality of spaced triggers. Hence, a measured amount of sand introduced by means of a sand container into a moulding frame and a filling frame over a pattern can be packed to form a mould body.
For packing granular materials, particularly foundry moulding materials, by means of an exothermic reaction of a mixture of air and fuel in a combustion chamber, a relative movement between the combustible mixture and one or more pulse triggers is produced during the exothermic reaction, for example by a blower disposed in the combustion chamber, by means of movable pulse triggers or sequential ignition of a plurality of spaced triggers. Hence, a measured amount of sand introduced by means of a sand container into a moulding frame and a filling frame over a pattern can be packed to form a mould body.
Description
The presen-t invention rela-tes -to a process and to an apparatus for packing or compressing granular materials.
The process and apparatus are particularly suitable for packing foundry moulding material, although -they are not 5 limited to this application.
An explosion packing process hitherto in the foundry industry for the production of moulds and cores (see U.S. Patent No. 3,170,202) has not progressed beyond the experimental stage.
In particular the following factors proved -to be disadvantageous:
- Safety risk in the storage and handling of ~- . explosive materials in the foundry area;
- Lack of reproducibility of the achieved results;
- The necessary combustion pressures couLd only be achieved by pre-compressing the combustible mixture in the combustion chamber, which involves additi.onal expense and sealing problems;
- Without the use of additional oxygen the strength values necessary for :Eoundry purposes were not achieved;
- The use of additional oxygen made the process unduly expensive and increased -the safety risk.
According to the present invention there is provided a process for packing granular materials by means of an exothermic reaction of a combustible mix-ture of air and Euel in a closed system, wherein the exothe:rmic reaction is initiated during relatlve movement between the mixture and one or more initiating pulses.
According to the present invention there is also provided an apparatus for packing granular materials, which apparatus comprises a plate for receiving the granular material to be packed, a moulding-frame and a filling frame disposed on t~e plate, a combustion chamber mounted over -the filling ~ .
?~'i~e' 6~
frame, the combus-tion chamber having at least one fuel inlet aper-ture and at least one initiating pulse trigger, and means for producing a relative movement between the com-bustible mixture and the one or more initiating pulse trig-gers located within the combustion chamber or operatinglyconnected to the combus-tion chamber.
By these features a desired reproducible combus-tion process is achieved. At the same time an increase in the intensity of the exothermic reaction can also be achieved.
Of particular importance is -the increase in the propagation speed of the combustion process through the relative movement of the combustible mixture. Only after this step is it possible, without the use of additional oxygen, to increase the propagation speed so tha-t the necessary strength values are achieved.
The combus-tible mixture is preferably brought into a self-contained, closed-loop current, variable in its speed, by a power-variable blower, which is either in the combustion chamber itsel~ or is connected to the combus-tion chamber. The closed-loop current may be ei-ther turbulent or laminar. However, production ol movement is also possible for example with mixing valves or the like.
desired combustion process can also be achieved by the actuation of the initiating pulse triggers.
The power variability of the blower makes i-t possible, via the variable flow of the combustible mixture, to achieve a desired mould strength, according to the particular circumstances. The correlation between movement intensity and mould s-trength is hence a positive one, that is the greater the speed the grea-ter the mould strength.
. .~
~ ' .
5 ~3 Preferably, at least a part o~ the mixture should be moved at a speed o~ at least 1 ms , and typical speeds for the combustible mixture lie in the range of 20 - 50 ms The fuel is pre~erably introduced into the air in the combustion chamber which is at ambient pressure. When using a stoichiometric amount of, for example, natural gas, the pressure in the combustion chamber thus increases by about o.l bar. With a slight excess pressure of this kind there are no substantial sealing problems and hence no gas losses or safety problems.
The stoichiometric ratio between air and fuel does not, however, have to be adhered to; it is only essential that the resultant mixture remains combustible.
One can consider for fuels both solid materials as well as liquid and gaseous materials. The following have proved to be particularly suitable either alone or in mixtures:
natural gas, methane, propane, butane, acetylene, gasoline and diesel oil. Also pyrophoric dusts, such as coal dust, saw dust and the like, are suitable.
~o A further advantage o~ the process of the invention is the fact that the maximum pressure in the closed system, reached a~ter initiati~n of the combustion, is substantially 8 bar, which considerably simpli~ies -the construction o~ the packing apparatus and considerably lowers the stress on the apparatus.
With all explosion packing processes the surface of the packed mould becomes brittle and friable and the -combustion heat dries out a 5 - 10 mm thick sand layer.
One embodiment of the process o-f the invention allows the elimination of this disadvantage. It consists in -that the surface of the granular material to be packed is provided, be~ore initiation of the explosion, with a gas-impermeable cover. If the cover covers only a part o~ the sur~ace, for example, by means o~ a container open at the botto~ the side walls of which dip into the granular material, then at the same time the compressive strength at the top of the mould can be controlled locally.
A further possibility of controlling the mould strength on the upper surface of the mould, apart from the already i5~
mentioned power variability of the blower, lles in -the changing of the volume o~ the combustion chamber, again with positive correlation, that is the greater the volume.
of the combustion chamber the greater the mould strength.
The process and apparatus of the invention can not only be used in the foundry industry for the production of casting moulds and cores but can also be used in the building industry for packing building materials.
For a better understanding of the present invention and to show more clearly how it may be carried into efiect reference will now be made, by way of example, tc the accompanying drawings in which:-Figure 1 illustrates moulding equipment incorporatinga first embodiment of a device according to the present invention;
Figure 2 illustrates moulding equipment incorporating a second embodiment o~ a device according to the present invention;
Figure 3 illustrates moulding equipment incorporating a third embodiment o~ a device according to the present invention;
Figure 4 illustrates mouldlng equipment incorporating a fourth em~odiment o~ a device according to the present invention; and Figure 5 illustrates moulding equipment incorporating a fifth embodiment of a device according to the present invcntion.
Figure 1 sho-vs moulding equipment in which a pattern plate 5 with a pattern 6 mounted thereon comes into a filling and moulding station. Here the plate 5 is raised by means of a hydraulic lifting ram 7 against a sand container 17 containing a measured amount of moulding sand via a moulding frame 11 and a filling frame 12;
which are movable by means of rollers 13. After the sand has been poured into the moulding and filling ~rames, the container 17 is moved away horizontally and a cap 18 takes the place of the container 17. The cap 18, which : substantially iorms a combustion chamber 23 and which consists of an upper cover plate 24 and a side wall 25, has an i~i~al pulse trigger, for example an igniter 19, a blower 20 driven by an electric motor 22 and provided with a guide ring 20a and an inlet aperture 21 for fuel.
An amount o~ fuel guaranteeing ignitability is conveyed through a line 27 into the combustion chamber 23 which is filled with air at atmospheric pressure, ~vhereby the pressure rises minimally (for example with natural gas at the stoichiometric ratio the pressure rises by about 0.1 bar). The blower 20 mixes the air and fuel to form an explosive mixture. In order to be able to control the movement of the explosive mixture, the blower 20 is advantageously of variable power by means of blade adjustment or change in speed. The igniter 19 ignites the mi.xture when the blower 20 is operating, for example by an electrical spark, and the moulding sand is packed.
The maximum pressure increase is about 8 bar.
The drop in pressure depends, amongst other things, on the temperature of the wall wbich call be provided with cooling pipes 70 during continuous operation (automatic equipment) (see Figure 2). In addition, the exhaust gas escapes,for example through grouped vents and/or between the parts 5, ll, 12 and 25, Th~ excess pressure ~alls to ~ero when the ram 7 is lowered. The container 17 now comes into the ~illing position above the filling ~rame 12 and at the same time the cap 18 comes into a position 28 drawn in dotted lines, in which position an exhaust 29 removes the exhaust gases. Advantageouslythe blower 20 can remain constantly in operation in order to carry out 30 three functions : mixing the combustion components, :
increasing the propagation speed of the combustion front during combustion and expelling the exhaust gases.
The smaller the combustion chamber, the less fuel or combustible gas is used and the more cheaply can the device be produced.
Figure 2 shows a cap 18 which can slide in a frame 13 which fits on the filling frame 12, and which can be fixed in specific positions, for example by means of ~ins 34 which pass through apertures 35 in -the frame 33 and engage in -the side wall 25. On the outer side of the wall 25, seals 36 are advantageously pr~vided. This embodiment allows the optimum ratio o:E combustion chamber / sand filling volume to be adjusted respectively with different sized 5~ patterns. The adjustment of the cap 18 can also be effected by o-ther means, for example in a hydraulic or pneumatic manner, or electrically with the aid of a servo-motor.
Figure 3 shows two different features which may be combined. First of all a preferred arrangement of the blower 20 is shown. As shown in Figure 3, a suction no~zle 51 of the blower lies approximately coaxially over the sand or the pattern plate 5 so that the flow, which the pressure wa~e follows, runs downwards against the side wall. Thus the resistance between the sand and the wall can be compensated, at least partially, with the aim of obtaining even more uniform hardness values at the inter~ace.
Secondly another possibility is shown of affecting the mould streng-th along the interface. For this purpose a container 54, open at the bottom, is detachably connected to the wall 25 of the cap 18 by means of rods 52. After the ~illing process, the upstanding wall 53 of the container 54 dips into the sand, when the c:ap l3 is pressed against the moulding and filling ~rames 11, 12, in such a w~y that the surface 55, that is the closed end of the container 54, lies above the sand filling level 56. Surprisingly, it has been iound that by this means the compressive strength in tbe middle zone of the interface is reduced and in the wall zones it is somewhat increased.
~Vith fairly large moulding and iilling ~rames 11, 12, several blowers 20 can be arranged in the combustion chamber 23, and also other devices producing a movement o~ ~
the mixture, such as for example mixing valves and devices producing a wave movement of the mixture.
It is also possible, instead of a blower 20, to arrange one or more initial pulse triggers constructed as igniters 19 in the combustion chamber 23 on a rotating sha~t 80 ~see Figure 2, right-hand side), in which ignition time and rotation speed are preferably adjustable and hence an efficiently operating combustion process is obtained.
.
As a further variant, an arrangement of several igniters 19 distributed on the cap 18 around the circumference and over the height, is possible, these igniters being ignited simultaneously or according to a predetermined time schedule.
Figure ~ shows an embodiment in which combustion chamber 23 is arranged laterally of a moulding material container 57, and this chamber is connected via an aperture 58 to a lower combustion chamber part 23a.
Blower 20, driven by motor 22~ is connected to the cover Of the combustion chamber 23. The supply line 27 for a fuel and the one or more igniters 19 are in a side wall of the combustion chamber 23.
The axis of symmetry o~ the lower combustion chamber part 23a is the same as that of the moulding material container 57 which with its outlet aperture 59 can be inserted into the filling aperture 60 of the combustion chamber part 23a. A slide plate 61 is provided as a closure means for the filling aper-ture 60, and this plate can be moved transversely with respect to the filling aperture 60 by means of a thrust piston drive 62. The ~illing frame 12 and the moulding frame 11 are arranged with the same a~is of symmetry as the moulding material container 57 and can be lowered on rollers 13. ~, already described, the pattern plate 5 and pattern ~ are mounted on the plate of the lifting ram 7.
For the process of filling with moulding material, the slide plate ~1 is shifted into the open position and so tlle filling aperture is released. Next, by actuating the li~ting ram 7, the filling frame 12 is raised until it is in joining relationship with the combustion chamber part 23a. Now the closure of the moulding material container 57 is opened and a measured ~or dosed) amount of moulding material is fed in. Then the filling aperture - 60 is closed by means of the slide plate 61 and the lifting ram 7 is raised to the "Pressing" position. ~ith this process~ the combustion chamber part 23a is pressed against a ~rame 63 and hence the slide plate 61 is sealedly connected in position against the combustion chamber part ~i5.~
23a. Now the packing process can take place as ~lready described.
Figure 5 shows another embodimerlt in which a moulding frame 11, a filling frame 12 and a pattern plate 5, with pattern 6, sealedly connected to these ~rames by means of clamps 65, are disposed on a support 64. A housing 66 which covers the moulding frame 11, the filling frame 12 and the pattern plate 5 is placed on a seal 67 on the support 64 and is connected to the support by means of clamps 68. The blower 20 and motor 22 are mounted on one part oi the wall of the housing 66, and the fuel line 27 and the igniter 19 are mounted on the other part.
A carrier ring 69 is provided for raising and lowering the housing 66.
By using one or more catalysts, the combustion process with certain ~uels can be accelera-ted and at the same time by a choice o~ catalysts a desired reproducible combustion process can be achieved.
These catalysts can be o~ precious metals, for example platinum, gold or the like~ and can be arranged in the ~mbustion chamber 23 or can be introduced into the combustion chamber as additives with the fuel.
Thus) the illustrated embodiments oi the present invention permit the economical and safe production of moulds having a predetermined, high, reproducible compressive strength, without the need for additional oxygen or precompression.
.
The process and apparatus are particularly suitable for packing foundry moulding material, although -they are not 5 limited to this application.
An explosion packing process hitherto in the foundry industry for the production of moulds and cores (see U.S. Patent No. 3,170,202) has not progressed beyond the experimental stage.
In particular the following factors proved -to be disadvantageous:
- Safety risk in the storage and handling of ~- . explosive materials in the foundry area;
- Lack of reproducibility of the achieved results;
- The necessary combustion pressures couLd only be achieved by pre-compressing the combustible mixture in the combustion chamber, which involves additi.onal expense and sealing problems;
- Without the use of additional oxygen the strength values necessary for :Eoundry purposes were not achieved;
- The use of additional oxygen made the process unduly expensive and increased -the safety risk.
According to the present invention there is provided a process for packing granular materials by means of an exothermic reaction of a combustible mix-ture of air and Euel in a closed system, wherein the exothe:rmic reaction is initiated during relatlve movement between the mixture and one or more initiating pulses.
According to the present invention there is also provided an apparatus for packing granular materials, which apparatus comprises a plate for receiving the granular material to be packed, a moulding-frame and a filling frame disposed on t~e plate, a combustion chamber mounted over -the filling ~ .
?~'i~e' 6~
frame, the combus-tion chamber having at least one fuel inlet aper-ture and at least one initiating pulse trigger, and means for producing a relative movement between the com-bustible mixture and the one or more initiating pulse trig-gers located within the combustion chamber or operatinglyconnected to the combus-tion chamber.
By these features a desired reproducible combus-tion process is achieved. At the same time an increase in the intensity of the exothermic reaction can also be achieved.
Of particular importance is -the increase in the propagation speed of the combustion process through the relative movement of the combustible mixture. Only after this step is it possible, without the use of additional oxygen, to increase the propagation speed so tha-t the necessary strength values are achieved.
The combus-tible mixture is preferably brought into a self-contained, closed-loop current, variable in its speed, by a power-variable blower, which is either in the combustion chamber itsel~ or is connected to the combus-tion chamber. The closed-loop current may be ei-ther turbulent or laminar. However, production ol movement is also possible for example with mixing valves or the like.
desired combustion process can also be achieved by the actuation of the initiating pulse triggers.
The power variability of the blower makes i-t possible, via the variable flow of the combustible mixture, to achieve a desired mould strength, according to the particular circumstances. The correlation between movement intensity and mould s-trength is hence a positive one, that is the greater the speed the grea-ter the mould strength.
. .~
~ ' .
5 ~3 Preferably, at least a part o~ the mixture should be moved at a speed o~ at least 1 ms , and typical speeds for the combustible mixture lie in the range of 20 - 50 ms The fuel is pre~erably introduced into the air in the combustion chamber which is at ambient pressure. When using a stoichiometric amount of, for example, natural gas, the pressure in the combustion chamber thus increases by about o.l bar. With a slight excess pressure of this kind there are no substantial sealing problems and hence no gas losses or safety problems.
The stoichiometric ratio between air and fuel does not, however, have to be adhered to; it is only essential that the resultant mixture remains combustible.
One can consider for fuels both solid materials as well as liquid and gaseous materials. The following have proved to be particularly suitable either alone or in mixtures:
natural gas, methane, propane, butane, acetylene, gasoline and diesel oil. Also pyrophoric dusts, such as coal dust, saw dust and the like, are suitable.
~o A further advantage o~ the process of the invention is the fact that the maximum pressure in the closed system, reached a~ter initiati~n of the combustion, is substantially 8 bar, which considerably simpli~ies -the construction o~ the packing apparatus and considerably lowers the stress on the apparatus.
With all explosion packing processes the surface of the packed mould becomes brittle and friable and the -combustion heat dries out a 5 - 10 mm thick sand layer.
One embodiment of the process o-f the invention allows the elimination of this disadvantage. It consists in -that the surface of the granular material to be packed is provided, be~ore initiation of the explosion, with a gas-impermeable cover. If the cover covers only a part o~ the sur~ace, for example, by means o~ a container open at the botto~ the side walls of which dip into the granular material, then at the same time the compressive strength at the top of the mould can be controlled locally.
A further possibility of controlling the mould strength on the upper surface of the mould, apart from the already i5~
mentioned power variability of the blower, lles in -the changing of the volume o~ the combustion chamber, again with positive correlation, that is the greater the volume.
of the combustion chamber the greater the mould strength.
The process and apparatus of the invention can not only be used in the foundry industry for the production of casting moulds and cores but can also be used in the building industry for packing building materials.
For a better understanding of the present invention and to show more clearly how it may be carried into efiect reference will now be made, by way of example, tc the accompanying drawings in which:-Figure 1 illustrates moulding equipment incorporatinga first embodiment of a device according to the present invention;
Figure 2 illustrates moulding equipment incorporating a second embodiment o~ a device according to the present invention;
Figure 3 illustrates moulding equipment incorporating a third embodiment o~ a device according to the present invention;
Figure 4 illustrates mouldlng equipment incorporating a fourth em~odiment o~ a device according to the present invention; and Figure 5 illustrates moulding equipment incorporating a fifth embodiment of a device according to the present invcntion.
Figure 1 sho-vs moulding equipment in which a pattern plate 5 with a pattern 6 mounted thereon comes into a filling and moulding station. Here the plate 5 is raised by means of a hydraulic lifting ram 7 against a sand container 17 containing a measured amount of moulding sand via a moulding frame 11 and a filling frame 12;
which are movable by means of rollers 13. After the sand has been poured into the moulding and filling ~rames, the container 17 is moved away horizontally and a cap 18 takes the place of the container 17. The cap 18, which : substantially iorms a combustion chamber 23 and which consists of an upper cover plate 24 and a side wall 25, has an i~i~al pulse trigger, for example an igniter 19, a blower 20 driven by an electric motor 22 and provided with a guide ring 20a and an inlet aperture 21 for fuel.
An amount o~ fuel guaranteeing ignitability is conveyed through a line 27 into the combustion chamber 23 which is filled with air at atmospheric pressure, ~vhereby the pressure rises minimally (for example with natural gas at the stoichiometric ratio the pressure rises by about 0.1 bar). The blower 20 mixes the air and fuel to form an explosive mixture. In order to be able to control the movement of the explosive mixture, the blower 20 is advantageously of variable power by means of blade adjustment or change in speed. The igniter 19 ignites the mi.xture when the blower 20 is operating, for example by an electrical spark, and the moulding sand is packed.
The maximum pressure increase is about 8 bar.
The drop in pressure depends, amongst other things, on the temperature of the wall wbich call be provided with cooling pipes 70 during continuous operation (automatic equipment) (see Figure 2). In addition, the exhaust gas escapes,for example through grouped vents and/or between the parts 5, ll, 12 and 25, Th~ excess pressure ~alls to ~ero when the ram 7 is lowered. The container 17 now comes into the ~illing position above the filling ~rame 12 and at the same time the cap 18 comes into a position 28 drawn in dotted lines, in which position an exhaust 29 removes the exhaust gases. Advantageouslythe blower 20 can remain constantly in operation in order to carry out 30 three functions : mixing the combustion components, :
increasing the propagation speed of the combustion front during combustion and expelling the exhaust gases.
The smaller the combustion chamber, the less fuel or combustible gas is used and the more cheaply can the device be produced.
Figure 2 shows a cap 18 which can slide in a frame 13 which fits on the filling frame 12, and which can be fixed in specific positions, for example by means of ~ins 34 which pass through apertures 35 in -the frame 33 and engage in -the side wall 25. On the outer side of the wall 25, seals 36 are advantageously pr~vided. This embodiment allows the optimum ratio o:E combustion chamber / sand filling volume to be adjusted respectively with different sized 5~ patterns. The adjustment of the cap 18 can also be effected by o-ther means, for example in a hydraulic or pneumatic manner, or electrically with the aid of a servo-motor.
Figure 3 shows two different features which may be combined. First of all a preferred arrangement of the blower 20 is shown. As shown in Figure 3, a suction no~zle 51 of the blower lies approximately coaxially over the sand or the pattern plate 5 so that the flow, which the pressure wa~e follows, runs downwards against the side wall. Thus the resistance between the sand and the wall can be compensated, at least partially, with the aim of obtaining even more uniform hardness values at the inter~ace.
Secondly another possibility is shown of affecting the mould streng-th along the interface. For this purpose a container 54, open at the bottom, is detachably connected to the wall 25 of the cap 18 by means of rods 52. After the ~illing process, the upstanding wall 53 of the container 54 dips into the sand, when the c:ap l3 is pressed against the moulding and filling ~rames 11, 12, in such a w~y that the surface 55, that is the closed end of the container 54, lies above the sand filling level 56. Surprisingly, it has been iound that by this means the compressive strength in tbe middle zone of the interface is reduced and in the wall zones it is somewhat increased.
~Vith fairly large moulding and iilling ~rames 11, 12, several blowers 20 can be arranged in the combustion chamber 23, and also other devices producing a movement o~ ~
the mixture, such as for example mixing valves and devices producing a wave movement of the mixture.
It is also possible, instead of a blower 20, to arrange one or more initial pulse triggers constructed as igniters 19 in the combustion chamber 23 on a rotating sha~t 80 ~see Figure 2, right-hand side), in which ignition time and rotation speed are preferably adjustable and hence an efficiently operating combustion process is obtained.
.
As a further variant, an arrangement of several igniters 19 distributed on the cap 18 around the circumference and over the height, is possible, these igniters being ignited simultaneously or according to a predetermined time schedule.
Figure ~ shows an embodiment in which combustion chamber 23 is arranged laterally of a moulding material container 57, and this chamber is connected via an aperture 58 to a lower combustion chamber part 23a.
Blower 20, driven by motor 22~ is connected to the cover Of the combustion chamber 23. The supply line 27 for a fuel and the one or more igniters 19 are in a side wall of the combustion chamber 23.
The axis of symmetry o~ the lower combustion chamber part 23a is the same as that of the moulding material container 57 which with its outlet aperture 59 can be inserted into the filling aperture 60 of the combustion chamber part 23a. A slide plate 61 is provided as a closure means for the filling aper-ture 60, and this plate can be moved transversely with respect to the filling aperture 60 by means of a thrust piston drive 62. The ~illing frame 12 and the moulding frame 11 are arranged with the same a~is of symmetry as the moulding material container 57 and can be lowered on rollers 13. ~, already described, the pattern plate 5 and pattern ~ are mounted on the plate of the lifting ram 7.
For the process of filling with moulding material, the slide plate ~1 is shifted into the open position and so tlle filling aperture is released. Next, by actuating the li~ting ram 7, the filling frame 12 is raised until it is in joining relationship with the combustion chamber part 23a. Now the closure of the moulding material container 57 is opened and a measured ~or dosed) amount of moulding material is fed in. Then the filling aperture - 60 is closed by means of the slide plate 61 and the lifting ram 7 is raised to the "Pressing" position. ~ith this process~ the combustion chamber part 23a is pressed against a ~rame 63 and hence the slide plate 61 is sealedly connected in position against the combustion chamber part ~i5.~
23a. Now the packing process can take place as ~lready described.
Figure 5 shows another embodimerlt in which a moulding frame 11, a filling frame 12 and a pattern plate 5, with pattern 6, sealedly connected to these ~rames by means of clamps 65, are disposed on a support 64. A housing 66 which covers the moulding frame 11, the filling frame 12 and the pattern plate 5 is placed on a seal 67 on the support 64 and is connected to the support by means of clamps 68. The blower 20 and motor 22 are mounted on one part oi the wall of the housing 66, and the fuel line 27 and the igniter 19 are mounted on the other part.
A carrier ring 69 is provided for raising and lowering the housing 66.
By using one or more catalysts, the combustion process with certain ~uels can be accelera-ted and at the same time by a choice o~ catalysts a desired reproducible combustion process can be achieved.
These catalysts can be o~ precious metals, for example platinum, gold or the like~ and can be arranged in the ~mbustion chamber 23 or can be introduced into the combustion chamber as additives with the fuel.
Thus) the illustrated embodiments oi the present invention permit the economical and safe production of moulds having a predetermined, high, reproducible compressive strength, without the need for additional oxygen or precompression.
.
Claims (34)
1. A process for packing granular materials by means of an exothermic reaction of a combustible mixture of air and fuel in a closed system, wherein the exothermic reaction is initiated during relative movement between the mixture and one or more initiating pulses.
2. A process according to claim 1, wherein the relative movement is produced by a movement of the combus-tible mixture.
3. A process according to claim 2, wherein the mixture is moved in a closed loop current.
4. A process according to claim 2, wherein at least a part of the combustible mixture is moved at a speed of at least 1 mn-1.
5. A process according to claim 4, wherein the speed of the mixture is at least 20 mn-1.
6. A process according to claim 1, wherein the relative movement is produced by movement of at least one initiating pulse.
7. A process according to claim 1, wherein the mixture is formed in the closed system.
8. A process according to claim 7, wherein before initiation of the exothermic reaction the pressure in the closed system is equal to that outside the system or at the most has an excess pressure such as results from the introduciton of the necessary amount of fuel into the air in the closed system which is a-t ambient pressure.
9. A process according to claim 8, wherein a solid fuel is used.
10. A process according to claim 8, wherein a liquid fuel is used.
11. A process according to claim 8, wherein a gaseous fuel is used.
12. A process according to claim 11, wherein the gaseous fuel comprises a saturated hydrocarbon or a mixture of saturated hydrocarbons.
13. A process according to claim 1, wherein the maximum pressure in the closed system, reached after initiation of combustion, is substantially 8 bar.
14. A process according to claim 13, wherein the surface of the granular material to be packed is provided with a complete or partial gas-impermeable cover before initiation of the exothermic reaction.
15. A process according to claim 14, wherein the exothermic reaction is accelerated by means of a catalytic effect.
16. A process according to claim 3, wherein said loop current is turbulent.
17. A process according to claim 3, wherein said loop current is laminar.
18. A process according to claim 6, wherein the mixture is formed in the closed system.
19. A process according to claim 18, wherein before initiation of the exothermic reaction the pressure in the closed system is equal to that outside the system or at the most has an excess pressure such as results from the introduction of the necessary amount of fuel into the air in the closed system which is at ambient pressure.
20. A process according to claim 19, wherein a solid fuel is used.
21. A process according to claim 19, wherein a liquid fuel is used.
22. A process according to claim 19, wherein a gaseous fuel is used.
23. A process according to claim 22, wherein the gaseous fuel comprises a saturated hydrocarbon or a mixture of saturated hydrocarbons.
24. A process according to claim 23, wherein the maximum pressure in the closed system, reached after initiation of combustion, is substantially 8 bar.
25. A process according to claim 24, wherein the surface of the granular material to be packed is provided with a complete or partial gas-impermeable cover before initiation of the exothermic reaction.
26. A process according to claim 25, wherein the exothermic reaction is accelerated by means of a catalytic effect.
27. An apparatus for packing granular materials, which apparatus comprises a plate for receiving the granular material to be packed, a moulding-frame and a filling frame diposed on the plate, a combustion chamber mounted over the filling frame, the combustion chamber having at least one fuel inlet aperture and at least one initiating pulse trigger, and means for producing a relative movement between the combustible mixture and the one or more initiating pulse triggers located within the combustion chamber or operatingly connected to the combustion chamber.
28. An apparatus as claimed in claim 27, wherein the means for producing the relative movement comprises at least one blower for the mixture.
29. An apparatus as claimed in claim 28, wherein the or each blower is power-variable.
30. An apparatus as claimed in claim 27, wherein the means for producing the relative movement comprises one or more movable initiating pulse triggers.
31. An apparatus as claimed in claim 27, 28 or 29, wherein the volume of the combustion chamber is variable.
32. An apparatus as claimed in claim 27, 23 or 29, and including a container open at its bottom and connectible with the wall of the combustion chamber, the open side of the container lying below the granular material filling level and the closed side, opposite the open side, lying above the granular material filling level.
33. An apparatus as claimed in claim 30, wherein the volume of the combustion chamber is variable.
34. An apparatus as claimed in claim 30, and including a container open at its bottom and connectible with the wall of the combustion chamber, the open side of the container lying below the granular material filling level and the closed side, opposite the open side, lying above the granular material filling level.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH1015079A CH640437A5 (en) | 1979-11-14 | 1979-11-14 | Method and apparatus for compacting granular materials |
| CH10150/79-3 | 1979-11-14 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1165966A true CA1165966A (en) | 1984-04-24 |
Family
ID=4359914
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000364534A Expired CA1165966A (en) | 1979-11-14 | 1980-11-13 | Process and apparatus for packing granular materials |
Country Status (5)
| Country | Link |
|---|---|
| CA (1) | CA1165966A (en) |
| CH (1) | CH640437A5 (en) |
| ES (2) | ES8102838A1 (en) |
| NO (1) | NO155328C (en) |
| ZA (1) | ZA801799B (en) |
-
1979
- 1979-11-14 CH CH1015079A patent/CH640437A5/en not_active IP Right Cessation
-
1980
- 1980-03-26 ZA ZA00801799A patent/ZA801799B/en unknown
- 1980-05-16 ES ES491543A patent/ES8102838A1/en not_active Expired
- 1980-06-09 NO NO801717A patent/NO155328C/en unknown
- 1980-06-18 ES ES492532A patent/ES492532A0/en active Granted
- 1980-11-13 CA CA000364534A patent/CA1165966A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| ES491543A0 (en) | 1981-02-16 |
| ES8102486A1 (en) | 1981-01-16 |
| ZA801799B (en) | 1981-04-29 |
| NO155328C (en) | 1987-03-18 |
| NO801717L (en) | 1981-05-15 |
| CH640437A5 (en) | 1984-01-13 |
| NO155328B (en) | 1986-12-08 |
| ES8102838A1 (en) | 1981-02-16 |
| ES492532A0 (en) | 1981-01-16 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |