SU757173A1 - Extraction tower - Google Patents

Description

The invention relates to the refining and can be used in the purification of oil fractions polar solvents, such as phenol, furfural, etc., from unwanted components, which include polycyclic aromatic and naphthenic-aromatic hydrocarbons with short side chains, unsaturated hydrocarbons, sulfur and nitrogenous compounds, resinous substances.

Known extractors for cleaning fuel and oil fractions from unwanted components, the most common are vertical extractors [1].

The disadvantages of the known extraction columns are the low degree of contact between the raw material and the solvent, which slows down the process of extracting the most undesirable components from the raw material, and the poor quality of the raffinate.

Of the known extraction columns, the closest to the technical essence of the invention is an extraction column equipped with continuous horizontal partitions that divide the column into an appropriate number of sec2.

In the upper and lower parts of each section there are nozzles for outputting intermediate light and heavy phases, respectively, in the middle part each section has a mixer, to which pipelines _{5 are} connected to feed the light phase from the lower section and the heavy phase from the upper section ^ these pipelines equipped with regulating valves [2].

The disadvantages of this column are low volumetric capacity and low extraction efficiency.

The purpose of the invention is to increase the volumetric productivity of the extraction column, the yield and quality of the raffinate obtained during the purification of oil fractions with polar solvents.

⁵ This is achieved by the fact that the extraction column containing the tank, divided into sections with a blank plate, equipped with a helmet and drain pipes, contact devices in the upper section and fitting

About for the supply and removal of raw materials and solutions

it is supplied with vertical electrodes, installed under a deaf plate and made of horizontal pipes, with a source of electric current with which it is connected

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BUT

Yens are odd electrodes, and even-numbered electrodes are grounded and have one pipe larger than odd ones, as well as pipes installed below grounded electrodes and made with holes on their upper surface.

The drawing shows the proposed extraction column section.

It includes a vertical cylindrical container 1, which is divided into two sections by a blank plate 2. A blank plate 2 allocates a volume (section) at the bottom of the column, designed for 5–10-minute residence of raw materials in the area of the electrodes.

Blind plate 2 is equipped with a helmet 3 and drain 4 pipes for the flow of light and heavy phases, respectively. Helmet 3 and drain 4 pipes at the ends of the mother liquor 5 for uniform distribution of phases. To enter the raw mix (oil fraction with watered solvent) the column is equipped with a collector 6, taps 7 and perforated pipes 8 in the lower part. The perforated pipes 8 are installed under the bottom pipes of grounded electrodes 9 and provided with holes directed vertically upwards. Each grounded electrode 9 is connected to a perforated pipe 8 with a gap of 5-10 mm. A metal frame 11 is suspended to a deaf plate 2 on insulators 10, to which a voltage of 10–16 kV is supplied through a bushing 12. The working electrodes 13 are connected to a metal frame 11.

The grounded electrodes 9 are located between the working electrodes 13. All electrodes 9 and 13 are made of horizontal pipes in the form of vertical rows.

Electrode tubes have a diameter of 50-75 mm with a gap between the pipes horizontally and vertically not more than 150 mm. Each working electrode 13 consists of two three pipes, and the number of pipes in a grounded electrode 9 is one more.

In addition, the column is equipped with distribution plates 14, fittings 15 for entering the solvent and fittings 16 and 17 output raffinate and extract solutions, respectively, and several layers of packing 18.

Extraction column works as follows. in a way.

A mixture of an oil fraction with a solvent and water or a mixture of a fraction with an extract solution and water are fed into the extraction column 1 through the collector 6 at a specific ratio and temperature. The amount of solvent in the feed should be such that it does not completely dissolve in the feed at a given temperature and does not form a continuous phase (dispersion medium). Mixing the mixture components

produced to the column in pipelines and heat exchange equipment.

From the collector 6, the mixture through the taps 7 and perforated pipes 8 enters the zone of electrodes 9 and 13. The lower tube of a grounded electrode, installed at the apertures of the perforated pipe 8, splits the raw material flows, reduces its speed, promotes uniform distribution throughout the electric field and prevents the flow of raw materials with high electrical conductivity on the lower tubes of the working electrode 13.

In the electric field formed between the horizontal tubes of the working electrode 13 and the grounded electrode 9, watered solvent with the most undesirable components dissolved in it is removed from the raw material mixture.

Solvent particles with these components are deposited at the bottom of the column. Pre-cleaned raw materials with a certain amount of solvent that can dissolve in the oil fraction at a given temperature, passes through the area of the electrodes and through the helmet tube 3, which is provided with a blank plate 2, rises in the upper section (part) of the column for final cleaning.

The presence of electrodes in the form of a vertical row of pipes and oppositely charged electrodes in one horizontal row allows us to have different values of the electric field strength and the speed of movement of raw materials in the course of the movement of the raw material. In the horizontal planes, where the surfaces of the pipes approach due to their shape, the electric field strength and the flow velocity increase due to a reduction in the cross section.

The increased flow rate of the raw material contributes to the breaking of current-carrying chains, the formation process of which is accelerated at an increased electric field strength, and makes it impossible to cause a short circuit of the electrodes. Further, in the course of the movement of raw materials, the distance between the surface of oppositely charged pipes increases, which leads to a decrease in field strength and flow rate. This slows down the process of forming conductive chains, creates the conditions for their conversion into enlarged droplets and their subsequent deposition without shorting the electrodes.

Depending on the type of solvent, its amount in the mixture and the temperature of the raw materials in the area of the electrodes, up to 15–35% of undesirable components are given. In the upper part of the column, the pre-cleaned raw material comes into contact on the packing plates 18 with the bulk of the solvent supplied through the nozzle 15.

As a result of repeated contact

a solution is obtained at the top of the blueblood

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purified raw material (raffinate solution), which is displayed on the solvent regeneration through the fitting 16. The solvent containing the extracted undesirable components (extract solution), as having a higher density, ₅ accumulates over the deaf plate 2. Hence the extract solution continuously flows through the drain pipe 4 the lower part of the column under the collector 6 of the input of raw materials, where it is mixed with the primary extract solution isolated from the raw materials in the area of the electrodes, o With this mixing, the useful solution is displaced from the extract solution s components of the most undesirable components.

These useful components are transferred to pre-purified raw materials, increasing the yield of raffinate. The presence in the deaf plate 2 of the drain pipe 4 and the location of its end 300–400 mm below the perforated pipe does not allow the extract solution, which has a high electrical conductivity, to get into the 20 zone of the electrodes and cause them to short circuit. The extract solution obtained in the lower part of the column through the nozzle 17 is displayed on the regeneration of the solvent. This extract solution can be used as a component of the raw mix fed to the collector 6. The amount of the extract solution in the raw mix depends on its conductivity and the required quality of the raffinate. Installation of control valves on the helmet 3 and drain 4 of the pipes is not required.

The use of an extraction column with electrical section allows to increase the productivity of the column by 10%, to increase the selection of the raffinate by 4% with some improvement in its quality, as measured by the refractive index.

Claims (1)

Claim An extraction column containing a tank divided into sections with a blank plate with a helmet and drain pipes, contact devices in the upper section and fittings for supplying and discharging raw materials and solutions, characterized in that, in order to increase the volumetric productivity, yield and quality of raffinate, it is equipped vertical electrodes installed under a deaf plate and made of horizontal 4rub, a source of electric current, to which odd electrodes are connected, and even-numbered electrodes are grounded and have one pipe b proc eed than odd and pipes laid below ground electrodes, and made with openings on their upper surface.