The so-called reverberatory furnace is to separate the combustion chamber from the melting chamber, and use the dome structure with arc of the furnace to introduce the high-temperature flame and heating air in the combustion chamber into the smelting chamber to realize the separation of the processed material and the fuel, and avoid the pollution of the processed material by the fuel.

In the early days, people invented this furnace because of the need for iron refining.

The reverberatory furnace is a necessary thing for crossing, and it is natural that it will not be absent from the information of online writers.

Chen Xian designed the smelting chamber of the reverberatory furnace into an inclined trough, and the copper coin was placed at the upper end of the chute, and after being heated by the reflected flame, the tin and lead in the copper coin would first dissolve and flow down the chute to the outlet below the chute.

After a long period of controlled calcination, most of the tin and lead in the copper coins are separated, and the remaining copper will be further refined.

The pyrometallurgical refining of copper is based on the principle that most of the impurities in copper have a greater affinity for oxygen than copper, and the oxides generated are insoluble in copper.

The more primitive copper refining method is to use a reverberatory furnace to dissolve the copper, drum into the air to oxidize the copper and the impurities in it, the copper oxide formed after copper oxidation will be dissolved in the copper liquid, and the oxide formed by impurities is insoluble in the copper liquid, forming slag.

After the slag is removed, heavy oil is poured into the molten copper, or a green wood is inserted to reduce the copper oxide, and in the reduction process, in order to prevent the copper from being oxidized again, a layer of carbon is placed on the surface of the molten copper to prevent the oxidation reaction.

Chen Xian built a larger reverberatory furnace and installed more and larger bellows, which smoothly dissolved the copper into a liquid state.

After the copper is dissolved, the heated air is directly poured into the smelting chamber from the side to strengthen the oxidation reaction of the molten copper, and at the same time, from the operation door specially set aside on the side of the smelting chamber, the wrought iron wire woven cover filter is stretched out, and the oxide slag floating on the surface of the molten copper is constantly fished out.

After a period of refining, when the surface of the molten copper is not slag out, stop the fire in the furnace, open the operation door, sprinkle toner on the surface of the molten copper, and cover the surface of the liquid.

It stands to reason that heavy oil is a better reducing agent, but where did Chen Xian get the heavy oil, he asked people to insert Aoki into the copper solution to act as a reducing agent.

It turns out that the method is quite reliable, and the refined red copper is very beautiful.

The tin-lead alloy obtained by smelting copper coins was separated by Chen Xian according to the crystallization method recorded in the data.

The so-called crystallization method means that the solution of the tin-lead alloy will first crystallize and precipitate tin in the process of temperature reduction, and by using this principle, the lead-tin solution can be repeatedly heated and cooled to obtain tin crystals with higher purity.

This method is quite time-consuming and laborious, and it needs to be crystallized repeatedly to obtain high-purity tin, but fortunately, the melting point of tin and lead is not high, the processing is relatively easy, and Chen Xian's amount of tin is not large.

The information also records how to test the tin for large amounts of lead.

Tin is easy to react with a strong alkali to form tinic acid, while lead does not react with a strong alkali, and Chen Xian just has a strong alkali like potassium hydroxide in his hand.

Using this chemical principle, Chen Xian took a small amount of purified tin and mixed it with a strong alkali to observe whether there was any lead left in the end.

Through comparison, Chen Xian can distinguish whether the purification is effective, and according to the results of this experiment, he can judge the timing of fishing for tin crystallization, so as to formulate detailed process guidance for future mass production.

In the process of removing lead, the tin-lead alloy must first be smelted in a reverberatory furnace, and Chen Xian took this opportunity to have people use a filter made of fine iron wire to remove the ash and hard lumps in the solution.

These ash and hard lumps are impurities such as iron and arsenic, which are used to remove these two impurities by using the characteristics of tin-lead with a much lower melting point than iron and other impurities, which is called melting method in modern industry.

After these two steps of refining, the purity of the tin was high enough, and Chen Xian began to smelt the two metals of copper and tin into a bronze alloy according to the ratio of guncopper.

Because there was no zinc, Chen Xian first smelted it according to the ratio of copper 9 tin 1.

When casting the cannon, Chen Xian did not adopt the sand turning method, but directly tried to cast the iron mold.

The advantage of the iron mold is that it can be used repeatedly, the efficiency is higher, and there is no need to worry about the rapid evaporation of the water in the sand mold under high heat, which will cause pores in the gun body.

However, the use of iron mold casting will reduce the temperature of the casting body faster, the internal stress will be greater, and defective products will be more likely to occur.

However, as mentioned earlier, bronze can absorb stress very well because of its toughness and ductility, so this shortcoming has little impact on copper casting, but if the iron cannon is cast in this way, it will cause a higher defective rate of casting, and the quality of the iron cannon will be worse.

When installing the mold, Chen Xian took a vertical posture, and let the tail end of the cannon face downward, pouring layer by layer, so that even if the cast cannon has air holes, it will be easier to appear at one end of the muzzle because of buoyancy, so as to better ensure the quality of the rear end of the more important cannon.

Experiments show that although the iron mold has little impact on the copper cannon, it does not mean that there is no effect, and the copper cannon cast by the iron mold and the sand mold is compared, Chen Xian found that the deformation of the copper cannon cast by the iron mold is more obvious.

In order to eliminate the effect, Chen Xian adopted the preheating method, he installed the iron mold in an iron box, filled the iron box with heated hot sand, waited until the sand preheated the iron mold, and then poured bronze liquid into the mold.

After preheating, the deformation of the cast copper cannon is significantly smaller.

Chen Xian used a 22-millimeter cannon as a test material, repeated experiments, and finally he tested that in the absence of zinc, it is most appropriate to use an alloy with a ratio of 89% copper and 11% tin.

In order to improve the quality of the cannon, Chen Xian enlarged the drilling machine used to drill the musket and manufactured a boring machine specially for the cannon boring.

The shape of this boring machine is similar to that of the drilling rig that drills the barrel of a musket, and the operating principle is basically similar, the only difference is that it is not human power that drives this boring machine, but a water turbine.

After boring, the inner wall of the copper cannon is smoother, the dimensional accuracy is higher, the dimensional accuracy in the barrel is high, the matching accuracy of the shell can be improved accordingly, and the smaller the clearance in the gap between the shell and the barrel, the greater the accuracy and power of the shell.

In addition to the power of accuracy, for artillery, the most important thing is probably the gun carriage, without the gun carriage, the bulky cannon can only be used as a tool to defend the city, with a flexible gun carriage that can pull the cannon around, the cannon can become the king on the battlefield.

Chen Xian naturally did not forget the design and manufacture of the gun carriage, and from the moment he made up his mind to make a cannon, Chen Xian had already begun to consider the design of the gun carriage.

Chen Xian was not thinking about inventing a new gun carriage, but about how to restore the gun carriage in the photo of the Napoleonic gun in the Internet writer's profile.

Chen Xian's industrial accumulation at this time naturally could not be compared with the Napoleonic era, so he could not build that kind of exquisite light gun carriage.

Chen Xian's existing conditions and technological level, the main trunk of the gun carriage body is made of wood, some vulnerable structural parts are made of iron, some of which are cast and forged, the wheel hub is made of wood structure and covered with iron plates, and the spokes are made of forged iron bars......

Chen Xian originally wanted to use a more advanced lead screw to adjust the elevation angle of the cannon, but after trying, he found that although he could make a lead screw, it was limited to the strength of the knife, and the strength of the lead screw produced was not enough, and the strength of the lead screw was not enough.

Chen Xian could only look back and consider using a wedge to adjust the angle of fire.

……

Just when Chen Xian was wholeheartedly building a cannon and testing it, a crisis was coming to him!