FR2795068A1 - APPARATUS FOR PROCESSING GRANULAR PYROTECHNIC PRODUCTS - Google Patents

Abstract

The technical field of the invention is essentially that of devices for mixing granular pyrotechnic products such as powders for a tube weapon. The object of the present invention relates to an apparatus (10) consisting of a cylindrical tank (2), the height is less than the radius of the tank (2) in which rotate horizontally, thanks to a drive motor (1), at least two arms (3) provided with blades (4) orientable. The invention also relates to use of such an apparatus as a mixer for granular pyrotechnic products, such an apparatus being able to be used as a simple dryer.

Description

The technical field of the invention is that of treatment devices.

  granular pyrotechnic products such as, for example, powders for tube weapons. The present invention relates more specifically to the use of these devices as mixers, such treatment devices being close to the dryers.

  can be used in the pyrotechnic industry.

  Mixers and dryers have already been specially designed for granular pyrotechnic products, but no mixer closely resembles the essential technical characteristics of dryers since, until the present invention, there was no general purpose appliance and there was no had not been discovered that a certain particular type of dryer made it possible to perform very efficiently

  mixtures of granular pyrotechnic products.

  It should be noted that the mixing operations relate to the same type of powder generally coming from different batches, and not to

  different types of powder at the same time.

  The object of the present invention relates to a versatile apparatus for processing granular pyrotechnic products, characterized in that it consists of a cylindrical tank whose height is less than the radius of the tank in which rotate horizontally, thanks to a motor. drive, at least two arms provided with blades, each of these blades being integral with a vertical axis which can pivot in a bore of said arms. Preferably, the axis of the tank is vertical and the blades are represented by flat objects of substantially rectangular shape similar to solid spatulas. According to another embodiment of the invention, the blades have a

central opening.

  Advantageously, each arm has at least three blades.

  According to a first embodiment of the invention, the bottom of the tank is flat. Preferably, the tank has at least one foot of variable length and a drain orifice located at the periphery of the flat bottom, so as to cause the draining of the apparatus by tilting the tank. In fact, at the end of the treatment operation, the tank is inclined so as to lower the part of the flat bottom where the drain orifice is located. The powder can then be discharged through the orifice. Advantageously, each blade is provided with its own means of rotation, allowing it to rotate on itself, around its vertical axis, in particular when the arms are moving in the tank. Preferably, the means of

  individual rotation is an electric motor.

  According to a second embodiment of the invention, the bottom of the tank is conical. Advantageously, the blades are orientable. According to a preferred embodiment of the invention, the tank has a frustoconical shape, the top of which is situated at a level below that of the periphery of the tank, said top comprising a central drainage orifice. During the treatment operation, the orifice is closed and, once the operation is complete, it is opened to empty the tank. Preferably, the drive motor is placed above the tank. Advantageously, the motor can produce different rotational speeds

  according to its operating regime.

  The invention also relates to the use of a processing apparatus provided with blades for carrying out an operation of mixing granular pyrotechnic products. Advantageously, the mixing operation is combined with a smoothing operation. According to another variant of the invention, the mixing operation is combined with a graphitization operation. In fact, the apparatus for processing granular pyrotechnic products5, notably involving a horizontal cylindrical tank, arms fitted with blades and a drive motor, are perfectly suited to simple mixing, mixing and smoothing or mixing operations and graphitization. The only modification10 made to these treatment devices to go from a "dryer" configuration to a "mixer" configuration is the removal of one of the two envelopes constituting the double envelope of the tank, not because of its influence on the mixture but

rather of its uselessness.

  Finally, the invention relates to a mixer of granular pyrotechnic products in accordance with

  treatment equipment described above.

  The major advantage of the apparatus for treating granular pyrotechnic products according to the invention is that it is versatile and that it makes it possible, among other things, to carry out operations as sought after as

drying or mixing.

  In addition, these versatile devices are instantly convertible into mixers or dryers

without special interventions.

  Finally, from a safety point of view, the apparatus according to the invention has the advantage of little confining the pyrotechnic product in the treatment phase and of avoiding the production of rapid bursts in the event of setting.

on fire or deflagration.

  A detailed description is given below

  three preferred variants of a device according to

  the invention with reference to Figures 1 to 5.

  Figure 1 is a diagram in partial axial section along the plane I-I of the first preferred variant

  of a treatment apparatus according to the invention.

  Figure 2 is a diagram in partial axial section along the plane II-II of the apparatus of Figure 1. Figure 3 is a diagram in partial axial section along the plane III-III of the second preferred variant

  of a treatment apparatus according to the invention.

  Figure 4 is a diagram in partial axial section

  according to plan IV-IV of the apparatus of FIG. 3.

  FIG. 5 is a diagram in partial axial section of the third preferred variant of an apparatus for

treatment according to the invention.

  Referring to Figures 1 and 2, the first variant 10 of the treatment apparatus according to the invention comprises a motor 1, a tank 2, four horizontal arms 3 provided with adjustable blades 4, and four feet 5 of fixed length distributed uniformly under the tank 2. The motor 1 is raised relative to the tank 2 and is positioned at the right of the center of the said tank 2. The engine 1 is held by three rigid bars 6, placed between them at 120 one of the other, and connecting the circular edge of the tank 2. The motor 1 rotates a vertical shaft 8, the end of which ends in four horizontal arms 3 of length less than the radius of the tank 2, each arm making its following an angle of 90. The tank 2 has a frustoconical shape, the top of which is situated at a level lower than that of the lowest part of the cylindrical crown constituting the body of the tank 2. The top of the conical bottom of the tank 2 ends in a neck cylindrical 7 serving as a drain orifice and being closed by a cover external to said tank 2. Each arm 3 has six regularly spaced blades 4 along its length, each consisting of a rod extended by a spatula of substantially rectangular shape. The blades 4 are found in a vertical position under the arms 3 which support them, and each spatula can be oriented around the vertical axis 5 formed by the rod which ensures its connection with the arm 3. The blades 4 belonging to the same arm 3 can to be

orientable simultaneously.

  The end of each spatula, closest to the conical bottom, has the same inclination as the bottom of said tank 2 when the blades 4 are oriented

  parallel to the arms 3 which support them.

  The tank 2 is kept in a horizontal position

  thanks to the four 5 feet which support it.

  The operation of the first preferred variant of the apparatus 10, in the mixer configuration is simple: The mixing powder generally coming from different batches is poured into the tank 2 until completely or partially covering the spatulas which have been previously oriented and then fixed in a direction for which, during the mixing phase, the powder will tend to migrate towards the periphery of the tank 2, so as to compensate for the natural movement of the grains towards the center of said tank 2 due to the slope of the conical bottom. This orientation of the blades 4 will depend on the direction of rotation of the arms 3. The arms 3 are then rotated about a vertical axis by the motor 1 and the regular passage of the blades 4 contributes to mixing the powder. The mixing operation can then last several minutes depending on the amount of powder to be mixed. Once the operation is complete, the cover closing the cylindrical neck 7 ending the top of the conical bottom is removed to empty the tank 2 and

recover the mixed powder.

  The mixing operation ensured by the mixer 10 according to the invention and which consists in sliding the grains one over the other by an inversion effect, makes it possible to simultaneously carry out smoothing or graphitizing operations. Smoothing is an operation which consists in spraying, onto the powder grains, a solution containing an agent making it possible to modify the rate of combustion of the powder.10 Graphitizing is an operation which consists in coating the powder grains with an agent antistatic, such as graphite, which can appear, either dry under

  in powder form, either in the form of a solution.

  These various agents are conveyed into the tank 2 filled with powder by clean means separate from the mixer, such as, for example, nozzles, or manual operations carried out with common commercial tools. The homogeneity and the quality of the mixture allow

  combine these two additional operations.

  Referring to Figures 3 and 4, the second preferred variant 20 of the treatment apparatus according to the invention also involves a motor 21, a tank 22, four horizontal arms 23 provided with blades 24 oriented parallel to said arms 23 which support them, and four feet 25 uniformly distributed under the tank 22. This second variant 20 differs from the first 10, in that the motor 21 is placed under the tank 22, that the tank bottom 22 is flat, that the 'drain port 27 is placed at the periphery of the tank bottom 22 and that the feet 25 each comprising a hydraulic cylinder have a variable length. The mode of operation of this second variant 20, as a mixer is similar to that of the first preferred variant 10 of the apparatus described above. The only difference is the emptying phase of the tank 22 filled with mixed powder. Indeed, for the second variant 20, once the mixing operation is complete, the tank 22 is inclined so as to lower the part of the flat bottom where the drain orifice 27 is located, and the arms 23, always in rotation, allow the blades 24, each time they pass above the orifice 27,

to evacuate the mixed powder.

  The mixing performance of the second variant is such that it also makes it possible to combine smoothing or graphitizing operations with these mixing operations, in the same manner as for the

  first variant 10 described above.

  Finally, with reference to FIG. 5, the third preferred variant 30 of the treatment apparatus according to the invention involves a tank 32 with a flat bottom, a drive motor 31 intended to rotate around a vertical axis four horizontal arms 33, provided with blades 34 each having a vertical axis connecting them to the arms 33 which support them and four feet 35 distributed uniformly under the tank 32. Like the second variant 20, a drain orifice 37 is placed at the periphery of the bottom of tank 32 to allow, at the end of the treatment operation, the evacuation of the powder. This third variant 30 differs from the second 20, by the fact that each of the blades 34 is provided with an individual motorization 39 allowing it to rotate on itself, around its vertical axis, while the arms 33 are in movement rotating in the tank 32. Each of the individual motors 39 is located on the upper part of the arms which support the blades 34, in a position diametrically opposite to that of the blade 34 which it will drive in rotation. This third variant 30 takes up the operating principle of the planetary mixer having a compound action on the powder grains, namely, a general mixing on the scale of the tank 32 dQ at the rotation of the arms 33, enriched with localized mixing caused by the rotation of the blades 34 on themselves. This equipment in mixer configuration generates such a quality of mixture that it can suit an extremely wide range of

  granular pyrotechnic products to be treated.

Claims (13)

Claimq   1. Multipurpose apparatus for treating granular pyrotechnic products, characterized in that it consists of a cylindrical tank (2, 22) whose height is less than the radius of the tank (2.22) in which rotate horizontally, thanks to a drive motor (1, 21), at least two arms (3, 23) provided with blades (4, 24), each of these blades (4, 24) being integral with a vertical axis which can pivot in a bore of said arms (3, 23).   2. Treatment apparatus according to claim 1, characterized in that each arm (3, 23) comprises at minus three blades (4, 24).   3. Treatment apparatus according to any one   claims 1 or 2, characterized in that the bottom of the tank (2) is flat.   4. Treatment apparatus according to claim 3, characterized in that the tank (22) has at least one foot (25) of variable length and a drain opening (27) located at the periphery of the flat bottom, so as to cause emptying of the apparatus (20) by tilting the tank (22).   5. Treatment apparatus according to claim 3 characterized in that each blade (34) is provided with its own means of rotation (39) allowing it to rotate on itself, around its vertical axis, in particular when the arms ( 33) are moving in the tank (32). 6. Treatment apparatus according to any one   claims 1 or 2, characterized in that the bottom of the tank (2) is conical.   7. Treatment apparatus according to any one   claims 1 or 6 characterized in that the blades (4.24) are adjustable.   8. Treatment apparatus according to claim 6, characterized in that the tank (2) has a frustoconical shape whose top is located at a level below that of the periphery of the tank (2), said   top with a central drain opening (7).   9. Treatment apparatus according to any one   of claims 1 to 8, characterized in that the   drive motor (1) is placed above the tank (2). 10. Use of processing equipment with   blades (24) according to one of claims 1 to 9   previous steps to perform a mixing operation of   granular pyrotechnic products.   11. Use of a treatment apparatus according to claim 10, characterized in that the operation   mixing is combined with a smoothing operation.   12. Use of a treatment apparatus according to claim 10, characterized in that the operation   mixing is combined with a graphitization operation.   13. Mixer of granular pyrotechnic products, characterized in that it conforms to one of the   Claims 1 to 9 above.