Байланысты: XXI ҒАСЫРДАҒЫ ХИМИЯ ЖӘНЕ ХИМИЯЛЫҚ ТЕХНОЛОГИЯНЫҢ ЗАМАНАУИ ЖЕТІСТІКТЕРІ МЕН ТЕНДЕНЦИЯЛАРЫ-ХИМИЯ-2023-06-05 14 54 57pm
«СОВРЕМЕННЫЕ ДОСТИЖЕНИЯ И ТЕНДЕНЦИИ ХИМИИ И ХИМИЧЕСКОЙ ТЕХНОЛОГИИ В XXI ВЕКЕ» «XXI ҒАСЫРДАҒЫ ХИМИЯ ЖӘ НЕ ХИМИЯЛЫҚ ТЕХНОЛОГИЯНЫҢ ЗАМАНАУИ ЖЕТІСТІКТЕРІ МЕН ТЕНДЕНЦИЯЛА РЫ» - equipping the vacuum column with a regular nozzle with low
hydraulic resistance; -preliminary mechanical activation of crude oil;
- by installing an additional column.
Using a regular nozzle with low hydraulic resistance.
Initially, plates with low mass transfer efficiency and high hydraulic
resistance were used as contact devices of vacuum columns in the blocks
of vacuum distillation of fuel oil. This led to an increase in energy
consumption for distillation, the amount of decomposition gases formed
and a decrease in the quality of the vacuum distillates obtained [1].
In the global oil refining industry, regular-type nozzle contact
devices are widely used for vacuum distillation of fuel oil, which have
significantly lower hydraulic resistance per unit of theoretical plate,
compared with poppet contact devices.
The currently used vacuum columns with regular packing devices
can be divided into two types according to the method of organizing the
mutual movement of contacting liquid and steam flows: counter-current
and cross-current [2].
Countercurrent nozzles are made of perforated corrugated sheets,
which are then bonded together into finished sections.
The main distinguishing features of countercurrent nozzles from
poppet contact devices:
- significantly lower hydraulic resistance; -high separation capacity.
However, regular attachment devices also have a number of
disadvantages, such as:
- high cost and complexity of manufacturing;
- the complexity of organizing an even distribution of irrigation
over the entire area of the nozzle. Distillation of fuel oil in industrial
conditions is usually accompanied by the introduction of water vapor in
the amount of up to 1.5% of the mass of fuel oil into the vacuum column
cube. Along with the positive effect (improvement of the stripping of
hydrocarbons), there are also negative effects: the need to increase the
cross-sectional area of the column, dilution of hydrocarbon vapors and,
due to this, a decrease in the efficiency of the distillation column plates,
an increase in the load on the vacuum creation system.
A partial solution to this problem is the reconstruction of the vacuum
column with equipping it with regular nozzles with low hydraulic
resistance. The hydraulic resistance of the column directly affects the
selection of vacuum gas oil according to the following basic pattern: the
hydraulic resistance increases in proportion to the square of the increase
in the selection of vacuum gas oil. So regular nozzles with low hydraulic
resistance of the company
«
Koch - Glitsch
» , with steam and liquid
distributors, allow to increase the total output of vacuum distillates and
improve their quality.
In addition to the Koch - Glitsch nozzles, there are many other
regular countercurrent nozzles with low hydraulic resistance per
theoretical plate. Russian and foreign refineries mainly use regular
countercurrent nozzle devices developed by such companies as Glitsch
(Jam Pack), Zulzer (Mellapak), Cedar-89 (VAKUPAK) [3].
The main advantage of the cross-flow nozzle over the counter-flow
is that the counter-flow nozzle occupies the entire cross-section of the
column, and steam and liquid move towards each other, and the cross-
flow nozzle occupies only part of the cross-section of the column (in the
form of various geometric shapes: ring, triangle, quadrilateral, polygon,
etc.) and the flow of liquid is carried out from top to bottom, while the
vapor phase goes across the direction of the liquid flow.
A representative of this type of nozzles is the
«
PETON
» nozzle [4].
The developed regular cross-flow nozzle
«
PETON
» , in contrast to the
known types of contact devices, such as a high-flow nozzle, direct-flow
devices, cross-flow plate, allows you to combine the advantages of these
devices and substantially eliminate their disadvantages. The cross-flow
regular nozzle
«
PETON
» has the ability to independently adjust the section
for the passage of steam in the nozzle from the section for the passage of
liquid when designing the column. This property of the cross current in
the nozzle makes it possible to solve the problem of organizing effective
contact with unequal flow rates of steam and liquid in the column.
Bench tests of the PETON nozzle, confirmed by industrial tests
of columns in various processes with unequal steam and liquid loads,
showed:
- choking of the column occurs, on average, at loads 2.5 times greater
than with the counterflow of phases on regular nozzles;
- the efficiency of one section of the column with the
«
PETON
» nozzle is from 60% to 99% with the height of the sections commensurate
with the inter-tube distance in the column equipped with plates;
- special partitioning and redistribution of steam and liquid flows
increases efficiency, on average, by 1.5 times;
- The WATT of the column with the
«
PETON
» nozzle is 400 - 1000 mm.
Preliminary mechanical activation of crude oil
The method of mechanical activation of crude oil, which allows to
increase the yield of vacuum gas oil during distillation under vacuum,
is currently very ambiguous, but quite promising.