Processes and apparatus of chemical technology

Modern chemical technology is associated with grinding, crushing, transportation of various materials. Some of them are converted in the process of treatment into an aerosol form, the dust formed together with the ventilation and process gases enters the atmosphere. Let us consider the basis of chemical technology, which is currently used in production.

Apparatus for cleaning dust from gaseous substances

Dust particles have a high total surface, as a result they exhibit increased biological and chemical activity. Some of the substances in the aerosolized form appear new properties, for example, they are capable of spontaneously exploding. There are various apparatuses of chemical technology used to purify the gaseous substances formed in the production from a variety of dust particles and sizes.

Despite the significant differences in design, the principle of their operation is based on the delay of the weighted phase.

Cyclone and dust collection chambers

Analyzing various processes and apparatuses of chemical technology, we will focus on a group of dust-collecting apparatus, which include:

• Rotary dust collectors;
• Cyclones;
• Blind models;
• Dust collection chambers.

Among the advantages of such devices, we note the simplicity of their design, so they are produced in non-specialized enterprises.

As a minus of such devices, professionals note insufficient efficiency, the need for re-cleaning. All types of dust collecting apparatus function on the basis of centrifugal forces, differ in power and speed of precipitation of dust particles.

For example, the classical chemical technology for the production of sulfuric acid involves the use of a cyclone for purification from the impurities of the furnace gas formed during the burning of pyrite. The gas, in which there are particles of cinder (mixed iron oxide) enters the cyclone through a special tangential branch, then rotates along the inner walls of the apparatus. Accumulation and deposition of dust is carried out in the dust collector, and the purified gas rises upward, leaves into the next apparatus through the central tube.

Chemical technology is associated with the use of a cyclone in cases where high requirements are not imposed on the resulting gaseous substance.

Wet cleaners

A wet method in modern production is considered one of the most productive and simple types of purification of industrial gases from a variety of suspended particles. Processes and apparatuses of chemical technology associated with wet gas purification are now in demand not only in domestic but also in foreign industry. In addition to suspended particles, they are able to capture gaseous and vaporous components, which reduce the quality of products.

There is a subdivision of such apparatuses into packed hollow, foam and bubbling, turbulent and centrifugal types.

The disintegrator consists of a rotor and a stator equipped with special guide blades. The liquid is fed into the rotating rotor through the nozzles. Due to the gas flow moving between the stator and rotor rings, it is milled to separate droplets, resulting in increased contact of gases with trapped liquid particles. Thanks to the centrifugal forces, the dust is thrown to the walls of the apparatus, then it is removed from it, and the purified gaseous substances enter the next apparatus or are released into the atmosphere.

Porous Filters

Often, chemical technology involves the filtration of substances through special porous septa. This method assumes a high degree of purification from a variety of suspended particles, so porous filters are in demand in chemical production.

Their main disadvantages are the need for a systematic replacement of filter components, as well as large dimensions of devices.

Industrial filters are divided into granular and tissue classes. They are intended for purification of industrial gaseous substances having a high concentration of dispersed phase. To carry out the periodic removal of accumulating particles in the apparatus, special regenerating devices are installed.

Features of oil refining

Thin chemical technologies associated with refining petroleum products from mechanical impurities and high humidity are based precisely on filtration processes.

Among those processes and devices that are currently used in the petrochemical industry, filtering through coalescing partitions and ultrasound is isolated. With the help of centrifugal separators, coalescent filters, settling systems, a preliminary cleaning stage is carried out.

In order to perform complex purification of petroleum products, porous polymer compositions are currently used as a filter material.

They have confirmed their effectiveness, strength, reliability, so they are increasingly using common chemical technology.

Electric Filters

Chemical processes in the technology of sulfuric acid production presuppose the use of this apparatus. The efficiency of purification in them is from 90 to 99.9 percent. Electrofilters are able to capture liquid and solid particles of different sizes, the devices operate in the temperature range of 400-5000 degrees Celsius.

Due to low operating costs, these devices have become very popular in modern chemical production. Among the main shortcomings typical for such equipment, we will allocate significant initial costs for their construction, as well as the need to allocate a large space for installation.

From the economic point of view, it is advisable to use them when cleaning significant volumes, otherwise the use of electrostatic precipitators will be a costly exercise.

Contact device

Chemistry and chemical technology involves the use of a variety of devices and devices. Such an invention as a contact device is intended for carrying out catalytic processes. An example is the oxidation of sulfur oxide (4) to sulfurous anhydride, which is one of the steps in the technological production of sulfuric acid.

Due to the radial-spiral year, the gas passes through a layer with a catalyst located on special partitions. Thanks to the contact device, the economy of catalytic oxidation is significantly increased, and the maintenance of the device is simplified.

A special removable basket, which has a protective layer of catalyst, allows you to replace it without any problems.

Firing furnace

This apparatus is used in the production of sulfuric acid from iron pyrites. The chemical reaction proceeds at a temperature of 700 ° C. Due to the principle of counterflow, which assumes the supply of oxygen in air and iron pyrites in opposite directions, a so-called fluidized bed is formed. The bottom line is that the particles of the mineral are distributed evenly over the volume of oxygen, which guarantees a qualitative passage of the oxidation process.

After completion of the oxidation process, the resulting "cinder" (iron oxide) falls into a special bunker, from which it is periodically removed. The resulting furnace gas (sulfur oxide 4) is sent to the dust cleaning, then drained.

Modern furnace for firing, used in chemical production, can significantly reduce the loss of reaction products, while simultaneously increasing the quality of the resulting furnace gas.

In order to accelerate the process of oxidation of pyrite in the kiln for roasting, in the production of sulfuric acid, the raw material is preliminarily ground.

Shaft Furnaces

Blast furnaces, which form the basis of ferrous metallurgy, are referred to such reactors. The charge enters the furnace, contacts the oxygen fed through special openings, and then the obtained cast iron is cooled.

Various modifications of such devices have found their application in processing not only iron, but also copper ores, processing of calcium compounds.

Conclusion

It is difficult to imagine a full-fledged life of a modern man without using it as a product of chemical production. The chemical industry, in its turn, can not fully work without the use of automated and mechanical technologies, the use of special equipment. At present, chemical production is a complex set of equipment and machines that are designed for chemical-physical and chemical processes, automated equipment for packing and transporting finished products.

Among the main machines and devices in demand in such production, those that allow to increase the working surface of the process, carry out high-quality filtration, complete heat transfer, increase the yield of reaction products, and reduce energy costs.