河北联合大学
Gas liquid mass transfer equipment consists of plate column and packed
column two categories.Distillation operation can not only adopt the plate tower,
also can be used in packing tower.Plate tower in the industry is the earliest use of
the bubble tower, tower, thereafter, especially in this century after fifty time, along
with the petroleum, chemical industry production develops quickly, appeared in
succession a large number of new tower trays, such as S plate, float valve tower
plate, multiple downcomer trays, tongue shaped tower plate, perforated ripple tray,
float jet tray and angle steel tower plate.From the current domestic and foreign
practical use situation, the main tower plate type sieve plate tower, float valve tower and bubble tower, while the former is widely used.
In the chemical industry, oil refining, pharmaceutical, food and environmental
protection industries, the tower is an important unit operation equipment.Its wide
application, a large amount of.According to statistics, tower equipment regardless
of their investment costs or all the weight of the steel consumption, in the whole process equipment in proportion is high.
Distillation is the separation of the most commonly used liquid mixture of a
chemical, oil refining, in industrial application is very broad.It is through steam,
liquid direct contact, using component volatilization of different, so that the volatile
components from liquid to vapor transmission, which is difficult to volatilize liquid transfer by steam, steam, liquid phase mass transfer between processes.
This design is stupid - chlorobenzene continuous separation of distillation
tower, and is a important basic raw material of organic synthesis, used as a dye,
medicine, pesticide, organic synthesis intermediates.Used in the manufacture of
5
河北联合大学
phenol, nitrochlorobenzene, two nitrochlorobenzene, aniline, nitrophenol and
insecticide DDT, also used as ethyl cellulose and many resin solvent.Application of
downstream products, nitrochlorobenzene is the main consumer of chlorobenzene,
nitrochlorobenzene is of vital dyes, pesticides, pharmaceutical intermediates.In
order to nitro - chloridize benzene as raw materials to production of p-nitrophenol,
p-nitroaniline, amino phenol, benzene two amine, p-aminophenol methyl ether and
amino benzene ether and a series of organic chemical products.But as a result of
Using Benzene Chlorination of chlorobenzene, benzene and chlorobenzene
miscible, so we need to design a distillation column used for the separation of volatile benzene and not easy to volatilize and chlorobenzene.
First of all, benzene and chlorobenzene raw material in the raw material
preheater of heating to boiling point, then, from raw materials into the feed inlet
into the distillation tower.Because of being heated to boiling point, a mixture of
both gas phase mixture, and the mixture in liquid phase, when the raw material
mixture was separated from the gas mixture, in the distillation tower rises, and the
liquid mixture in distillation tower in fall.Gas phase mixture to rise to the top of the
tower at the top of the condenser, the vapor mixture is cooled down to the bubble
point, wherein the liquid portion into the top product cooler, stop for a certain time
and then into benzene storage tank, and wherein the gaseous component back
into the distillation tower, this process is called return.Liquid phase mixture from
the bottom of the tower into a portion to the bottom of the tower product cooler,
one part enters the reboiler, the reboiler is heated to boiling point back to the
distillation column.Tower of the mixture to repeat the process, and the feed port
6
河北联合大学
has the fresh raw materials adding.Finally, complete the benzene and chlorobenzene separation.
Packed tower belongs to the differential contact type gas-liquid mass transfer
equipment.Tower to packing as a gas-liquid contact and mass transfer of basic
components.The liquid in the filler surface as a film flows from top to bottom, gas
and liquid phase bottom-up was continuous countercurrent flow, and the heat and
mass transfer of gas-liquid two phase.Two component concentration or temperature along the height of a continuous change.
Plate tower is a sequential contact of gas-liquid mass transfer
equipment.Tower to tower plate as a basic component, gas from tower bottom
upward to bubble live spray form, through the tower plate of the liquid layer, so
that the gas - liquid phase in close contact and mass transfer and heat transfer, two-phase component concentration was a step change.
Considering the plate tower as the ratio of packed tower stable performance,
high efficiency, convenient installation and maintenance and low cost, the design of plate column.
Plate is a plate tower main component, divided into a cross-flow plate and
counter-flow plate two, industrial applications to cross-flow plate, used a cross-flow plate mainly bubble tower, tower, float valve tower.
Sieve plate tower in relative phase load, efficiency, reliability and price was
lower than the other two Tayou, therefore the design selection of sieve plate tower, its features are as follows:
It has the advantages of simple structure, convenient manufacture repair;
7
河北联合大学
·
Large production capacity, higher than the float valve tower; Plate lower pressure drop, suitable for vacuum distillation;
Tower plate efficiency is high, but slightly lower than the float valve tower;
·
·
Rational design of sieve plate taco is highly flexible, only slightly and bubble
tower; ·
Small aperture plate is easy to be blocked, it is not appropriate treatment of
dirty, viscous and with solid particles in liquid.
This design topic is the separation of benzene and chlorobenzene rectifying
tower design, namely the design of a distillation column used for the separation of
volatile benzene and chlorobenzene not volatile, with continuous operation, the specific process parameters are as follows:
Processing capacity: 12000 tons / year
Liquid composition (containing chlorobenzene): 34%
Product composition (chlorobenzene purity): 99%
Overhead product composition (containing chlorobenzene: ≤ 1.5%) Operating pressure: the pressure 4KPa (gauge)
Thermal conditions of feed and reflux ratio of optional
Tower bottom heating steam pressure: 0.5MPa (gauge)
Single plate pressure drop: ≤ 0.7KPa
Earthquake intensity: 7 degrees
Soil conditions: second types of site soil
Local pressure =100kPa
Equipment working time: 300 days (day 24 hours of continuous operation)
8
河北联合大学
Power supply: source of water is enough, the normal power supply
For the 16MnR, =0 plate negative deviation, thus the nominal thickness.But
for low alloy steel vessel, shall not include corrosion allowance minimum thickness
shall be not less than 3mm, with 5mm corrosion allowance, nominal thickness of at least 8mm.
Because the head partially warp curvature change is smooth and continuous,
so the stress distribution is relatively uniform, and semi spherical head elliptical
head depth is much smaller, easy forming, is present in low pressure container, which is often applied in the head.The design of elliptical head.
Tower of the hand hole is the operator of the tower for inspection and repair of.Model design of hand hole DN250 welding neck flange hole.
The process needs to take over, in the tower design over size are DN32, DN50, DN65, DN80, DN125, all connecting pipes are not reinforced.
9
毕业论文精馏塔外文翻译--
