GB2233430A - Solid propellant blocks. - Google Patents
Solid propellant blocks. Download PDFInfo
- Publication number
- GB2233430A GB2233430A GB8426528A GB8426528A GB2233430A GB 2233430 A GB2233430 A GB 2233430A GB 8426528 A GB8426528 A GB 8426528A GB 8426528 A GB8426528 A GB 8426528A GB 2233430 A GB2233430 A GB 2233430A
- Authority
- GB
- United Kingdom
- Prior art keywords
- block
- propellant
- process according
- sections
- bonding composition
- 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.)
- Granted
Links
- 239000004449 solid propellant Substances 0.000 title claims description 10
- 239000003380 propellant Substances 0.000 claims description 48
- 238000000034 method Methods 0.000 claims description 35
- 239000000203 mixture Substances 0.000 claims description 31
- 239000004020 conductor Substances 0.000 claims description 26
- 238000005266 casting Methods 0.000 claims description 16
- 238000001125 extrusion Methods 0.000 claims description 10
- 239000002904 solvent Substances 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 6
- 150000002148 esters Chemical class 0.000 claims description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 3
- 229910052802 copper Inorganic materials 0.000 claims description 3
- 239000010949 copper Substances 0.000 claims description 3
- 230000006837 decompression Effects 0.000 claims description 3
- 239000002184 metal Substances 0.000 claims description 3
- 229910052751 metal Inorganic materials 0.000 claims description 3
- 239000004014 plasticizer Substances 0.000 claims description 3
- 229910052709 silver Inorganic materials 0.000 claims description 2
- 239000004332 silver Substances 0.000 claims description 2
- 238000002485 combustion reaction Methods 0.000 description 15
- 238000004519 manufacturing process Methods 0.000 description 7
- URAYPUMNDPQOKB-UHFFFAOYSA-N triacetin Chemical compound CC(=O)OCC(OC(C)=O)COC(C)=O URAYPUMNDPQOKB-UHFFFAOYSA-N 0.000 description 6
- 235000013773 glyceryl triacetate Nutrition 0.000 description 3
- 239000001087 glyceryl triacetate Substances 0.000 description 3
- 229960002622 triacetin Drugs 0.000 description 3
- RUKISNQKOIKZGT-UHFFFAOYSA-N 2-nitrodiphenylamine Chemical compound [O-][N+](=O)C1=CC=CC=C1NC1=CC=CC=C1 RUKISNQKOIKZGT-UHFFFAOYSA-N 0.000 description 2
- SNIOPGDIGTZGOP-UHFFFAOYSA-N Nitroglycerin Chemical compound [O-][N+](=O)OCC(O[N+]([O-])=O)CO[N+]([O-])=O SNIOPGDIGTZGOP-UHFFFAOYSA-N 0.000 description 2
- 239000000006 Nitroglycerin Substances 0.000 description 2
- PZIMIYVOZBTARW-UHFFFAOYSA-N centralite Chemical compound C=1C=CC=CC=1N(CC)C(=O)N(CC)C1=CC=CC=C1 PZIMIYVOZBTARW-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000010304 firing Methods 0.000 description 2
- 229960003711 glyceryl trinitrate Drugs 0.000 description 2
- -1 nitrogylycerin Chemical class 0.000 description 2
- 239000003381 stabilizer Substances 0.000 description 2
- 235000015842 Hesperis Nutrition 0.000 description 1
- 235000012633 Iberis amara Nutrition 0.000 description 1
- 239000000020 Nitrocellulose Substances 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 229920001220 nitrocellulos Polymers 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02K—JET-PROPULSION PLANTS
- F02K9/00—Rocket-engine plants, i.e. plants carrying both fuel and oxidant therefor; Control thereof
- F02K9/08—Rocket-engine plants, i.e. plants carrying both fuel and oxidant therefor; Control thereof using solid propellants
- F02K9/26—Burning control
-
- C—CHEMISTRY; METALLURGY
- C06—EXPLOSIVES; MATCHES
- C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
- C06B45/00—Compositions or products which are defined by structure or arrangement of component of product
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02K—JET-PROPULSION PLANTS
- F02K9/00—Rocket-engine plants, i.e. plants carrying both fuel and oxidant therefor; Control thereof
- F02K9/08—Rocket-engine plants, i.e. plants carrying both fuel and oxidant therefor; Control thereof using solid propellants
- F02K9/24—Charging rocket engines with solid propellants; Methods or apparatus specially adapted for working solid propellant charges
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Crystallography & Structural Chemistry (AREA)
- Organic Chemistry (AREA)
- Wire Processing (AREA)
- Extrusion Moulding Of Plastics Or The Like (AREA)
- Pressure Welding/Diffusion-Bonding (AREA)
- Fuses (AREA)
Description
Process for making solid propellant blocks
incorporating heat-conducting elements, and
the blocks so obtained.
This invention is concerned with a process for making solid propellant blocks incorporating heat conducting elements which serve to increase the combustion rate of the blocks. Such propellant blocks are suitable for rockets, missiles and, in general, all vehicles propelled by solid propellants.
Processes for making solid propellant blocks incorporating heat conducting elements are known, for example from French Patent 1 349 125 and U.S. Patent 3 509 822. However, these processes can only be used for the production of cast blocks since the conductor elements are placed in the mould before casting the propellant; these processes do not enable heat conducting elements to be incorporated into propellant blocks formed by extrusion or into blocks formed by the assembly of several pre-formed block sections.
French Patents 1 595 508 and 1 605 454 describe processes in which propellant blocks with short combustion times are formed, by extrusion, in the form of longitudinally extending sections and including a plurality of longitudinal bores or channels. These serve to considerably increase the combustion surface of the block which burns in an essentially radial combustion pattern.
We have now developed a method of making propellant blocks incorporating heat conducting elements in which heat conducting elements are inserted into blocks obtained by casting, by extrusion, or by the assembly of a plurality of block sections and which is independent of the nature of the propellant.
According to the present invention there is provided a process for making solid propellant blocks incorporating heat conducting elements1 which comprises forming a propellant block and simultaneously or subsequently forming one or more longitudinally extending channels therethrough, inserting a heat conducting element into the or each such channel, and introducing a bonding composition into the or each such channel to bond the conductor element and the propellant block.
The present invention also comprises solid propellant blocks incorporating heat conducting elements, when made by the process according to the invention.
The propellant block may be made by extrusion, by casting or by the assembly of a plurality of longitudinally extending block sections together, the channels being formed between adjacent sections and the sections being secured together by pressure or by the use of a bonding composition. The bonding composition may be either a combustible or an inert composition depending on the nature of the propellant composition of which the block is formed.
Thus, for a block made of homogeneous propellant, it is preferred to use the casting solvent used in the production of the block as the bonding composition, for example a nitric ester, such as nitroglycerin. Such a casting solvent causes the propellant matrix to swell in the channels, thus gripping the conductor elements. The block obtained may then be subjected to heat treatment.
In a preferred embodiment of the invention, the bonding composition is introduced into the channels by decompression suction1 in a manner which is generally similar to the one used for production of a double base propellant block using the so-called casting method.
When the propellant block is formed by the assembly of a plurality of block sections, the heat conducting elements are placed in the channels between the sections before the latter are secured together.
The bonding composition used to bond the conductor elements to the block is preferably the same as the bonding composition used to secure the sections together.
The use of the same bonding composition for both purposes enables the propellant blocks to be produced in a single operation and the presence of the conductor elements facilitates the introduction of the bonding composition between the block sections. The block sections can be made by extrusion or casting and may, if desired1 themselves incorporate heat conducting elements.
In order that the invention may be more fully understood, preferred embodiments thereof will now be described, by way of example, with reference to the accompanying drawings, in which:
Figure 1 is a schematic longitudinal section of a propellant block,
Figure 2 is a similar view, on an enlarged scale, of portion II of Figure 1,
Figure 3 is a view of the rear face of another propellant block, and
Figure 4 is a view of the rear face of a third propellant block.
Figures 1 and 2 show an extruded propellant block adapted for frontal combustion. A propellant composition, such as a homogeneous propellant obtained using the solventless method, is extruded to form a block 1 comprising a plurality of longitudinally extending channels 2 which are essentially parallel to the longitudinal centre line of the block. A heat conducting element 3 is inserted into each channel.
The elements 3 are preferably metal wires preferably formed of silver or copper, having a diameter of from 0.1 mm and 1 mm, more preferably of 0.1 mm. However, the conductor elements 3 can be made of any material which has a thermal conductivity higher than that of the propellant forming the block. It can also be in the form of a strip or blade or similar shapes.
It is preferred to keep the conductor elements 3 in a tensioned condition by means of a system of springs attached to the ends of the elements or by equivalent means. Alternatively, the ends of the conductor elements may be simply attached to fixed parts of the installation so as to keep them in their correct positions inside the channels 2.
A bonding composition 4 is then introduced into each channel 2 to ensure the mechanical bonding of the elements 3 to the propellant 1, as clearly shown in
Figure 2. The composition 4 may either be cast through the upper part of the propellant block l or may be introduced into the channels by decompression suction.
In the latter case, the propellant block l with the conductor elements 3 is placed in a mould, the mould is closed and decompressed and the composition 4 is supplied to the lower part of the mould, from which it rises through the channels 2.
To ensure good bonding between the elements 3 and the propellant 1, the composition 4 must possess good bonding properties with respect to both the elements and the propellant and it is preferred that it should be capable of chemically reacting with a component of the propellant 1, for example the binder in the case of a composite propellant, or nitrocellulose in the case of a homogeneous propellant. The bonding composition 4 may be combustible or inert.
In a preferred mode of carrying out the process according to the invention, when the block 1 consists of a homogeneous propellant, such as an extruded or cast double base propellant, the composition 4 is the casting solvent used in the production of the propellant. Suitable such casting solvents comprise, for example, a nitric ester such as nitrogylycerin, and a plasticiser, such as triacetin, and, if desired, a stabilizer, such as 2-nitro-diphenylamine (2-NDPA) or centralite. Such a casting solvent causes the propellant 1 to swell, thus gripping the conductor elements 3.
Specific suitable bonding compositions (which are combustible) are, for example, as follows (by weight):
Example A Example B
Nitroglycerin 78% 72%
Triacetin 21.5% 27.5 Centralite 0-5% 0.50to Triacetin may, for example1 be used as an inert bonding composition 4.
Production of the block may be completed by a heat treatment, followed by the application of an inhibition coat 5 on all the faces of the block except the rear face, since the block is of the frontal combustion type. A suitable heat treatment of such blocks comprises, for example, maintaining the block at -400C for 24 hours, followed by quick heating to 600C and maintaining it at this temperature for 24 hours, this cycle being performed three times in succession.
It is preferred to form on the rear face of the block, a plurality of conical depressions 6 with their apices centered on the conductor elements 3; such depressions accelerate stabilization of the combustion surface of the block during operation.
It will be seen that the process described enables a propellant block to be formed and heat conducting elements to be inserted into it without the necessity for complex and specific tooling.
Referring now to Figure 3, the propellant block 7 is formed by assembling together a number of preformed block sections1 that is to say a central hexagonal section 8 and six other sections 9 located around the central section 8. The sections 8 and 9 can be formed by casting or extrusion. Heat conducting elements 3 are placed between the sections before the latter are secured together. The channels for the conductor elements are provided by the gaps between adjacent sections. In the case of a frontal combustion block, the elements 3 are placed essentially parallel to the longitudinal axis of the block. The elements are preferably metal wires, as mentioned previously.
In the embodiment of Figure 3, an element 3 has been placed at each apex of the hexagonal section 8.
The assembly of sections and conductor elements is then placed in a mould (not shown), such as the mould described in French Patent 1 605 454 and a bonding composition is introduced into the bottom of the mould and allowed to rise up between the sections to effect bonding; to facilitate this effect it is preferred to decompress the mould.
As before, when block sections 8 and 9 consist of a double base propellant, it is preferred that the bonding composition should be the casting solvent used to make the propellant and that it should comprise a nitric ester, a plasticiser and, if desired, a stabilizer as described above.
Manufacture of the block is completed by heat treatment, inhibiting and, if desired1 the formation of conical depressions on its rear face, as described above in relation to Figure 1.
The location of conductor elements 3 can be varied. Thus, in the embodiment shown in Figure 4, the elements 3 are placed at the mid-points of the longitudinal faces of the sections 8 and 9. If desired, longitudinally extending grooves may be formed on the faces or at the apices of the sections 8 and 9 to better locate the conductor elements 3. The sections 8 and 9 may also comprise one or more internally located conductor elements 3a as shown in Figure 4. The conductor elements 3a may be incorporated into the sections using the process according to the invention. In this case, the sections 8 and 9 are formed with a longitudinally extending channel, preferably made by extrusion. If the sections 8 and 9 are made by casting, it is preferred to incorporate the conductor elements 3a during the casting stage using the process of our Application (French Application 83. 17044).
It will be seen that the process described with reference to Figures 3 and 4 enables the conductor elements to be inserted during the block section assembly stage. This procedure offers the further advantage that it facilitates assembly of the sections in that the elements 3 placed between the sections separate the faces of the sections and thus facilitate and assist introduction of the assembly bonding composition between the sections. It is thus possible to produce readily blocks with a larger cross-section than the maximum that can be produced by extrusion. This procedure also facilitates the insertion of a large number of elements 3 so that the combustion time of the blocks can be reduced without detriment to their mechanical properties.
Test firings of propellant blocks with the configuration shown in Figure 4 and made by the process according to the invention, have been carried out in a fixed test enclosure with a 5 mm dia. nozzle and at temperatures of -300, 200C and 500C. The results obtained are summarized in Table I below.
Table I Propellant Conductor Firing t Pme Va Vi n
c element temp. (sec) (bars) (mm/sec)(mm/sec)
Double base, Copper +500C 3.59 266.1 93.3 27.4 3.4 solventless wire +200C 5. 20 174.2 64.4 27 2.4 method and dia.
extruded 0.lmm -300C 7.25 128.4 46.2 24 1.9 where:
Pme is the mean combustion pressure
Va is the apparent combustion rate of the block, equal to:
length of conductor element t
C t is the duration of combustion at a steady rate
c Vi is the intrinsic combustion rate of the propellant n = Va = multiplication factor
Vi
These tests show, firstly, that the incorporation of heat conducting elements into the propellant block does not disturb the combustion of the block and, secondly, that the combustion rate multiplication coefficient is in the region of 2 to 3.5.
Claims (16)
1. A process for making solid propellant blocks incorporating heat conducting elements, which comprises forming a propellant block and simultaneously or subsequently forming one or more longitudinally extending channels therethrough, inserting a heat conducting element into the or each such channel, and introducing a bonding composition into the or each such channel to bond the conductor element and the propellant block.
2. A process according to claim 1, in which the propellant block is made by extrusion or casting and the channel(s) is/are formed simultaneously.
3. A process according to claim 1, in which the propellant block is formed by assembling a plurality of longitudinally extending block sections together, the channels being formed between adjacent sections.
4. A process according to claim 3, in which the bonding composition used to bond the conductor elements to the block is also used to bond the block sections together.
5. A process according to claim 3 or 4, in which the block sections have a polygonal cross-sectional shape, and the conductor elements are located at apices of the sections or on the flat longitudinal faces of the sections.
6. A process according to any of claims 3 to 5, in which one or more conductor elements is/are incorporated in the body of one or more of the block sections.
7. A process according to any of claims 3 to 6, in which the block sections are formed by extrusion.
8. A process according to any of claims 1 to 7, in which the block is formed of a homogeneous propellant and the bonding composition is the casting solvent used to make the propellant.
9. A process according to claim 8, in which the bonding composition comprises a nitric ester and a plasticiser.
10. A process according to any of claims 1 to 7, in which the bonding composition is an inert, nonenergetic, composition.
11. A process according to any of claims 1 to 10, in which the bonding composition is introduced into the channel(s) by decompression suction.
12. A process according to any of claims 1 to 11, in which, following the introduction and setting of the bonding composition, the block with its conductor elements is subjected to heat treatment.
13. A process according to any of claims 1 to 12, in which the heat conducting elements are metal wires having a diameter of from 0.1 mm to 1 mm.
14. A process according to claim 13, in which the wires are formed of copper or silver.
15. A process for making solid propellant blocks incorporating heat conducting elements substantially as herein described with reference to Figures 1 and 2,
Figure 3 or Figure 4 of the accompanying drawings.
16. Solid propellant blocks incorporating heat conducting elements when made by the process claimed in any of the preceding claims.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8317045A FR2640260B1 (en) | 1983-10-26 | 1983-10-26 | PROCESS FOR THE MANUFACTURE OF A PROPERGOL BLOCK COMPRISING THERMALLY CONDUCTIVE ELEMENTS, AND BLOCK OBTAINED BY THIS PROCESS |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2233430A true GB2233430A (en) | 1991-01-09 |
| GB2233430B GB2233430B (en) | 1991-06-26 |
Family
ID=9293536
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8426528A Expired - Lifetime GB2233430B (en) | 1983-10-26 | 1984-10-19 | Process for making solid propellant blocks incorporating heat-conducting elements,and the blocks so obtained |
Country Status (4)
| Country | Link |
|---|---|
| DE (1) | DE3438991A1 (en) |
| FR (1) | FR2640260B1 (en) |
| GB (1) | GB2233430B (en) |
| IT (1) | IT1224138B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109958548A (en) * | 2019-03-12 | 2019-07-02 | 湖北航天化学技术研究所 | A kind of rapid fire solid propellant rocket modularization charge process |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0707560A4 (en) * | 1993-05-04 | 1998-01-07 | Alliant Techsystems Inc | Improved propellant system |
| FR3014185B1 (en) * | 2013-12-04 | 2016-10-28 | Herakles | PYROTECHNIC LOADING AND GAS GENERATOR COMPRISING SUCH LOADING |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3509822A (en) * | 1960-06-09 | 1970-05-05 | Susquehanna Corp | Propellent grains |
| FR1349125A (en) * | 1961-09-26 | 1964-01-17 | Atlantic Res Corp | Improvements to propellants |
| US3613597A (en) * | 1964-01-16 | 1971-10-19 | North American Rockwell | Solid propellant grain |
| FR1595508A (en) * | 1965-04-08 | 1970-06-15 | ||
| GB1407661A (en) * | 1966-03-08 | 1975-09-24 | Mini Of Technology | Manufacture of propellant charges |
| DE1273395B (en) * | 1966-06-28 | 1968-07-18 | Nitrochemie Ges Mit Beschraenk | Solid propellant molded body |
| US3413384A (en) * | 1967-04-24 | 1968-11-26 | Thiokol Chemical Corp | Method of obtaining unidirectional orientation of monofilaments in curable elastomeric materials |
| FR2376098A1 (en) * | 1976-12-30 | 1978-07-28 | Poudres & Explosifs Ste Nale | PROCESS FOR PRODUCING PROPULSIVE LOADS OF DOUBLE-BASED PROPERGOLS BY HOT WELDING |
| JPS56134591A (en) * | 1980-03-18 | 1981-10-21 | Nissan Motor | End-burning type gas generating propellant grains |
-
1983
- 1983-10-26 FR FR8317045A patent/FR2640260B1/en not_active Expired - Lifetime
-
1984
- 1984-10-17 IT IT68027/84A patent/IT1224138B/en active
- 1984-10-19 GB GB8426528A patent/GB2233430B/en not_active Expired - Lifetime
- 1984-10-24 DE DE19843438991 patent/DE3438991A1/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109958548A (en) * | 2019-03-12 | 2019-07-02 | 湖北航天化学技术研究所 | A kind of rapid fire solid propellant rocket modularization charge process |
Also Published As
| Publication number | Publication date |
|---|---|
| IT8468027A0 (en) | 1984-10-17 |
| GB2233430B (en) | 1991-06-26 |
| FR2640260A1 (en) | 1990-06-15 |
| FR2640260B1 (en) | 1992-01-24 |
| DE3438991C2 (en) | 1992-10-08 |
| IT1224138B (en) | 1990-09-26 |
| DE3438991A1 (en) | 1990-11-08 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19961019 |