How to make a rocket engine with caramel fuel. Sugar caramel by evaporation method. Making sorbitol starch rocket fuel

Racket fuel is made from saltpeter and newspaper.

Any saltpeter can be used:

• POTASSIUM NITRATE: KNO3 - aka potassium nitrate, potassium nitrate, potassium nitrate, Indian nitrate (suitable for all parameters).
• SODIUM NITRATE: NaNO3 - aka sodium nitrate, sodium nitrate, Chilean nitrate (at high humidity it can become damp)
• AMMONIUM NITRATE: NH4NO3 - aka ammonium nitrate, ammonium nitrate, ammonium nitrate, nitrogen fertilizer (recipe with transformation)
• CALCIUM NITRATE: Ca (NO3) 2 - aka calcium nitrate, calcium nitrate, lime nitrate, Norwegian nitrate (recipe with transformation)

Making a solution of nitrate for impregnating newspapers

1. Take any container of a suitable size for your measurement (cap, bottle, glass, jar or bucket ;-) Don't do too much the first time! If nitrate in granules is larger than buckwheat, grind it to the size of table salt before measuring. Sugar is measured in the form of sand. You need to measure it as follows: Take a full measure with a slide and press it to seal (by hand force), add and press again. When the content stops thickening, bend the excess evenly along the edge of the measure with a ruler or pencil body. This will be one measurement (percent by weight is indicated in parentheses).

Saltpeter recipes

For potash nitrate:

3 volumes of saltpeter + 1 volume of sugar

Sequencing:

• Measure: 3 saltpeter (80%), 1 sugar (20%) and 3 times more water (12 measures, 300%).

The solution is ready.

For sodium nitrate:

2 saltpeter + 1 sugar

Sequencing:

• Measure: 2 saltpeter (70%), 1 sugar (30%) and 2 times more water (6 measures, 200%).
• Heat while stirring until completely dissolved.

The solution is ready.

For ammonium nitrate with conversion to sodium:

2 saltpeter + 2 baking soda (NaHCO3) or 1 washing soda (Na2CO3) + 1 sugar

Sequencing:

• Provide good ventilation!
• Measure: 2 saltpeter (40%), 2 baking soda (45%) or 1 washing and twice as much water (8 or 6 measures, 200%).
• Boil for about an hour until the smell of ammonia almost disappears.
• Add 1 part sugar (15%).

The solution is ready.

In order not to spoil the air in the room with ammonia released as a result of the reaction with soda, cook under a hood or in the open air! If this is not possible, the jar with the solution can be placed outside the window on the windowsill. You can use a small boiler for heating.

For ammonium nitrate with conversion to potash:

3 nitrate + 3 potassium chloride (KCl) or 1 potassium carbonate (potash) (K2CO3) or 1 potassium sulfate (K2SO4) + 1 sugar

Sequencing:

• Measure: saltpeter, potassium and twice as much water.
• Transfer to any suitable container and mark the level.
• Boil for about an hour.
• Pour back into the container with the marked level and top up with water up to the mark.
• Add 1 part sugar.

The solution is ready.

For calcium nitrate with conversion to sodium or potassium:

3 saltpeter + 3 baking soda or potassium sulfate or potassium sulfate + 1 sugar

Sequencing:

• Measure: 3 saltpeter, 3 soda or potassium and twice as much water (12 scoops).
• Heat while stirring. The solution will turn cloudy white.
• Let it stand. The chalk formed will precipitate.
• Carefully drain the saltpeter solution from the sediment.
• Discard the sediment.
• Add 1 part sugar to the solution.

The solution is ready.

Impregnation of newspapers

If you burn a 5 cm piece of caramel paper folded several times or rolled into a roll for testing, it should actively burn out in about 3 - 5 seconds. with a "neon" flame. In one layer, it can burn unstably and even go out.

Several decades ago, when mankind raved about space exploration, the passion for rocketry was rampant. Both schoolchildren and adult men enthusiastically designed in garages and kitchens from scrap materials. Now the excitement has subsided a little, but what could be more exciting than launching a self-made aircraft into the air? How do you make a rocket take off? The most affordable and practical is to use caramel fuel, a mixture of nitrate and carbohydrates.

What is required

The set of components is not that great.

1. Sugar or sorbitol - raw material for caramelization.

2. Saltpeter (you can use different ones, more on this below).

3. Metal container - most often they take ordinary cans, although it is preferable to take dishes with thick walls - for more even heating. Even better - enameled or stainless steel, so that there is no reaction of the solution with the material of the dishes.

4. Electric stove - you cannot cook fuel on a gas stove!

5. Newspaper or other paper with good absorbency (if your goal is to make not just caramel fuel, but caramel paper). It is also used in rocket engines, impregnated with finished "caramel" and dried (without heating).

6. Protective equipment: glasses and gloves.

7. Ventilation.

Three manufacturing methods

There are many ways to make caramel fuel. The easiest thing is to simply mix the ingredients. Still "caramel" is cooked - simply or with evaporation. With normal mixing, the fuel is poured into glass jar and shake several times, then close tightly to prevent water absorption. When used directly in rocket engines, this type of fuel must be well sealed, otherwise an explosion is possible.

Caramel fuel is boiled, or rather melted at a temperature of 120-145 degrees until the sugar is completely converted and a mass is formed, similar in consistency to liquid semolina. It is not necessary to grind the components beforehand. It is very important to constantly stir it so that no air bubbles form. Evaporation cooking involves adding water and then evaporating it. Disadvantages of this method: moisture remains in the fuel, and this reduces the rate of its combustion.

Recipe number 1

Caramelized fuel is the best option. The ingredients are taken in the following proportions: sugar or sorbitol - 35%; saltpeter - 65%. Saltpeter is dried in a flat wide frying pan about 100-150 degrees for about two hours. Then grind for about 20 seconds - you can use a mortar or coffee grinder.

Lay in equal portions, 50 grams each. In order not to bother with grinding sugar, it is better to buy ready-made powdered sugar. For "boiled" caramel fuel, you do not need to grind or dry anything. To increase efficiency, 1% iron oxide (Fe 2 O 3) can be added to the mixture.

Recipe number 2

Sodium nitrate caramel fuel. The peculiarity of this mixture is that it is more hygroscopic. You will need 70% nitrate, 30% sugar and two volumes of water (200%).

Recipe number 3

It is not recommended to use it. fuel for (ammonium nitrate). Why is it better to pay attention to other recipes? Because it's an unstable compound and anything can go wrong when heated. As a result, the venture is likely to end in fire!

In addition, extremely toxic fumes are emitted from ammonium nitrate when making "caramel". Therefore, all recipes using ammonium nitrate contain additional components to convert it to sodium or potassium. The easiest option is with sodium. We take 40% nitrate, 45% baking soda and 200% water. We note the level of the liquid and evaporate until the smell of ammonia disappears. Then we add water to the original level (it has partially evaporated), add 15% sugar and wait for it to dissolve.

Catalysts

To increase the efficiency of the "caramel", various catalysts are added to it. The most popular is iron oxide. Less well known are caramel fuels with aluminum. Attention! A mixture of aluminum and nitrates can ignite in the presence of water. Particularly dangerous is the presence of any alkaline impurities that may be present in nitrate that is not pure enough or made on your own. Therefore, in a fuel based on nitrates with aluminum as a catalyst, it is necessary to add 0.5-1% of some weak acid, and it is not a fact that this amount will be enough - it all depends on the quality of nitrate. Borna - the best option... Oxalic and acetic acid are not suitable - aluminum reacts with them. If during the cooking process the mixture heats up very much, foams and emits a pungent smell of ammonia, you must immediately remove it from the stove and immerse it in water.

In general, it is better for experienced rocket scientists who have mastered the simplest types of fuel to experiment with catalysts. And it doesn't hurt to learn chemistry: it's easy to use ready-made advice, but knowledge and understanding of what you are doing and what reactions occur in the mixture are much more valuable.

Aluminum is added to the potassium caramel. Allowable variations are from 2.5 to 20%. A different amount gives a different change in the rate of combustion of the fuel. It is recommended to use spherical aluminum ASD-4.

How to stay whole and healthy

The most dangerous thing is to prepare caramel fuel by melting sugar and saltpeter, but this option is also the most effective. The container in which the "caramel" is cooked must be perfectly clean - foreign substances can cause a fire.

There should be no sources of open flames nearby - we don't need explosions in the kitchen. It is very important to monitor the temperature of the mixture - it should not rise above 180 degrees under any circumstances!

It is best to use a wooden stick when stirring to avoid side reactions. It should be mixed very carefully, but evenly: air bubbles in the finished fuel, when used, lead to an explosion of the rocket. When pouring this fuel into molds, care must also be taken that there are no bubbles. It is necessary to work with a hood or in the fresh air, especially for a recipe with ammonium nitrate.

Do not grind sugar and saltpeter together in a coffee grinder! Grind separately, mix, shaking, in a glass container.

Beginners should not mess with ammonium nitrate: first try the simplest and safest (based on potassium nitrate) caramel fuel. The manufacture of any home-made fuel must take place under the strictest control of the quality of ingredients, temperature, moisture content and in compliance with all safety measures!

Where to get ingredients

Saltpeter is sold in agricultural stores and summer residents' departments as fertilizer. Sorbitol is a sugar substitute for diabetics. Sold, respectively, in a pharmacy. Fe 2 O 3 - iron oxide - used to be sold under the name You can try to make it yourself by studying the relevant literature. Mineral hematite - this also aluminum is sold by manufacturers of chemical reagents.

Sometimes you want something strange. Here, recently I was drawn to rocket modeling. Since I build rockets at the Nubian level, for me a rocket consists of two parts - an engine and a body. Yes, I know that everything is much more complicated, but even with this approach, rockets fly. Naturally, you are wondering how the engine is made.

I want to warn you that if you are going to repeat what is written in this article, you will do it at your own peril and risk. I do not guarantee the accuracy or safety of the proposed technique.

For the motor housing, I use thick-walled PVC pipes 3/4 inch diameter. Pipes of this diameter are relatively cheap and readily available. The pipes are best cut with special scissors. I suffered a lot, trying to cut such pipes with a jigsaw - it always turned out very crooked.

I mark the pipe like this:

All dimensions are in inches. who does not know, the size in inches must be multiplied by 2.54 and you get the size in centimeters. I found these dimensions in a wonderful book

There are a bunch of other designs too. The upper piece of the engine (which is empty) I do not do. There should be an expelling charge for the parachute, I'm still far from that.

The cut piece of pipe is inserted into a special device. I will show you all the adaptations at once, so that there are no questions:

A long stick plays the role of a "pestle" Clay and fuel are compacted with it. The second piece is the conductor. It serves to drill the nozzle exactly in the center of the engine. Here are their blueprints:

The drill is used long - 13cm long. It is just enough to drill a channel through all the fuel.

Now you need to knead the fuel. I use the standard "caramel" - sugar and saltpeter in a ratio of 65 saltpeter / 35sugar. I don’t want to melt caramel - it’s a risky job, and it’s not worth the hemorrhoids. I'm not trying to get the best out of the fuel. This is amateur rocket science. I just mix the powdered sugar and saltpeter:

We hammer in the powder according to the marking. You need to hit pretty hard.

Fuel plugging and plugging are no different. It seems that knocking on fuel is dangerous, but caramel is difficult to ignite even from a match. Naturally, basic precautions should be taken - do not lean over the engine, work in a protective mask, etc.

I leave the last 5mm plugs for the hot melt glue. Several times I tried to make a rocket without a plug from hot melt glue, the top plug was pulled out by pressure. Hot glue has excellent adhesion to plastic and does not have time to melt when the engine burns.

We drill the nozzle through the jig:

Fuel is very poorly drilled - the sugar melts and sticks to the drill, so you often have to pull it out and clean off the stuck fuel. Checking the nozzle:

Fill the last 5mm of the tube and its end with hot melt glue

That's it, the engine is ready. This is what the engine looks like in static tests. Unfortunately, the video is not indicative - in this engine, the channel was drilled in half, and the camera did not record the sound correctly. In real life, the "roar" of the engine is very loud and serious, and not as toy-like as on the record.

Production of MIKS-1 sugar starch rocket fuel using the evaporation method (Rcandy type)

Obtaining caramel fuel by evaporation has long been known. One of the most successful evaporation technologies is considered to be a technique invented by the American rocket scientist Rcandy. In our conditions, it is difficult to accurately repeat his method for various reasons, on which I will not dwell. I just propose my adaptation called MIX-1. It is simpler in terms of both components and technology. Of course, I did not make comparisons with the original, but the successful use of fuel in the TRDK-1 engine speaks of its suitability.

The advantage of the evaporation technique is clear.
Firstly, the components do not need to be ground, they will still be dissolved in water. Those. we take, for example, ordinary granulated sugar or powdered sugar, sorbitol and saltpeter straight from the package.
Secondly, there is no need to mix in advance. Stirring is done during the dissolution process.
And, thirdly, there is no need for strict control of the moisture content of the original components. The components, of course, must be taken dry enough so that moisture does not noticeably affect the weight proportions of the components. Usually the moisture content of the components in the original packaging is quite acceptable.

Fuel components:

Potassium nitrate KNO 3 - 65%
Sugar (sucrose) C 12 H 22 O 11 - 25%
Sorbitol (sorbitol) C 6 H 14 O 6 - 10%

Hot water should be taken by the weight of nitrate. To obtain fast-burning fuel, you can add 1-1.5% iron oxide Fe 2 O 3 on top. You can add oxide immediately, with all the components, or after the fuel is ready, when it has not yet thickened. This option was named MIKS-1K.

We buy sugar in a grocery store, sorbitol in a pharmacy, and saltpeter in a gardening store or in a specialized company.

We weigh the components in the required proportions and pour them into a vessel in which we will prepare the fuel. A small, thick-walled aluminum skillet works well. For small quantities you can take a steel crook. Fill with hot water and put on a hot stove.

Be sure to control the temperature of the heater surface

I wrote how to control heating in an article about sorbitol caramel.

At first, the tile temperature can be high 200-250 ° C. Bring our mixture to a boil and evaporate, stirring with a spoon.

The evaporation process requires constant monitoring.

When the mixture thickens and begins to bubble a lot, reduce the temperature to 175 ° C and continue evaporating with stirring.

After the active bubbling has ceased, the process can be continued without stirring.

At some point, bubbling practically stops, only rare single bubbles and a slight crackle indicate that the process continues. It's better to work in silence here. Set the temperature down to 150 ° C and listen carefully. When the crackling stops, the fuel is ready.

To make sure of this completely, you need to take some fuel, roll up a small sausage, put it on a metal surface and crush it into a cake. If, when bending, the cake "broke", then it is definitely ready. Reduce the temperature to 100-120 ° C and start placing the fuel in the molds.

Fuel is flexible enough, and installation is not difficult. A portion of the fuel is taken, rolled into a tight lump and put into a mold. Then the lump is manually tamped tightly into shape by the end of a thick metal rod. If necessary, the next lump is taken, placed on top and again rammed. When tamping, the caramel behaves like plasticine, forming a dense plastic packing, without air bubbles, which is very important.

It is very easy to form various channels in such a plastic charge, pushing the composition with a suitable rod. The charge solidifies quite quickly, but there is enough time for the formation of channels in the checker or the bonded charge. Within the next half hour, this is done without problems.

Rcandy writes that the fuel can be stored in a plastic bag and, if necessary, used by heating it to 100-120 ° C. I have not tested. I usually make as much fuel as needed for a particular charge.

Fuel characteristics are standard for sugar caramel.
The burning rate of MIKS-1 in air is 3.5-3.6 mm / s.
Burning rate of MIKS-1K fuel with feroxide catalyst 4.8-5.0 mm / s
Combustion temperature ~ 1700 ° C.

The technology is not complicated, although it takes time. The only requirement is constant process monitoring and temperature control. When these conditions are met, large quantities of caramel can be cooked fairly safely. / kia-soft 10/07/2010 / ***

In the process of working on the end motor, he came to the modernization of the MIKS-1K fuel manufacturing technology.
1. I pre-grind the iron oxide for 20 seconds in a coffee grinder.
2. I mix the catalyst in advance, before adding water.
3. After evaporation, I do not lower the temperature below 180 ° C, transferring the fuel to the melting phase.

The variation was named MIKS-1KP. Subjectively and objectively, the fuel turns out to be a little more active. The maximum thrust of the TRDK-1 end-piece on it increased by 17%. Burning speed in air 4.9-5.2 mm / s. There is a video of a sample test.

Instead of a conclusion.
As a result of the development of "fast" fuel, it received a little more than planned.
First, the proposed composition can be used both in the standard (MIKS-1) and "accelerated" (MIKS-1K) versions.
Secondly, the composition can be prepared both by evaporation and by melting, which favorably distinguishes it from the composition based on pure sugar. The presence of sorbitol prevents the sugar from decomposing when the fuel melts.
Thirdly, inadvertently developed new technology fuel preparation EVAPORATION-MELTING. It combines all the advantages of both technologies. According to preliminary estimates, MIKS-1KP fuel prepared using this technology is approximately 10% more active.

Related to blended fuels with an organic binder. The basic, most studied and frequently used composition is 65% KNO 3 and 35% sorbitol (by weight). Such a composition is close to the optimum in terms of the attainable specific impulse at small degrees of expansion, which are characteristic of model solid propellants. A moderate exponent in the law of combustion makes the fuel suitable for operation in a wide range of pressures, and, as a consequence, suitable for handicraft solid propellants with a noticeable scatter of geometric characteristics.

The energetic characteristics of this composition are very moderate. The theoretical specific impulse of caramel fuel on potassium nitrate is 153 kgf * s / kg, and practically achievable does not exceed 125 units. This is less than that of cheap ballistic fuels based on nitrocellulose, so this composition is not used industrially. However, this is significantly more than that of black powder, besides, the manufacture of caramel fuel does not require specific equipment necessary for the production of gunpowder, therefore it is popular with manufacturers of model rocket engines, both artisanal and serial commercial.

The main disadvantages of this fuel are hygroscopicity and a large amount of condensed phase in combustion products. It should also be recognized as a disadvantage that this fuel is fragile, which narrows the choice of solid propellant rocket engines with its use. Finally, the disadvantage is significant shrinkage (decrease in volume) during hardening, which can cause distortion of the shape of the checker or detachment of the armor.

When replacing sorbitol with sucrose in the fuel, the combustion rate increases quite significantly, by 40% at atmospheric pressure, but other properties of the fuel (density, specific impulse, exponent in the combustion law, etc.) hardly change. The main disadvantage of the sugar composition is the much more dangerous cooking process, since more heat is required.

Caramel fuel is so named because of the use of sugar or sorbitol in its composition, as well as because of appearance finished fuel. The English-language term "rocket candy" characterizes the attitude towards it in the same way.

Despite its relative safety compared to other formulations, caramel fuel requires the same precautions in use as any other rocket fuel, since it is a high-energy composition.

The original fuel has low toxicity, but the products of its combustion can irritate the mucous membranes and respiratory organs, since potassium carbonate, which is released in a highly dispersed form and has an alkaline reaction, can cause a chemical burn even after cooling to room temperature. The combustion temperature of the base composition is about 1400 degrees Celsius, this is enough to soften the steel body of the solid propellant rocket when exposed to it without thermal protection.

The finished fuel consists of a solid solution of nitrate in sorbitol and fine particles of undissolved nitrate suspended in it. The melting point of the finished fuel is much lower than that of the starting components. The solubility of nitrate in sorbitol in solid form is much less than in the melt, therefore, when the fuel cools down, it gains strength gradually, since crystals are released from the solid solution along the volume, and a certain amount of heat is released. Large checkers remain soft for more than a day.

The pioneer of the use of caramel fuel is Bill Colburn, who first used it in 1948, and this fuel gained wide popularity in the United States with the publication of Bertrand Brinley's book in 1960. Widely used in improvised rockets due to the availability of components.