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Wet lime-gypsum
desulphurizing process absorbs SO2 by the touch of gas
and liquid. The reacting procedure doesn’t reverse and isn’t
limited by balance. The desulphurizing efficiency is more than 95%.
The absorbing reaction is faster than that of limestone. The
desulphurizing agent lime of this process is widely used and easy to
get and make. The final product is gypsum, which can be used for raw
materials of building. It will not pollute the environment even if
it is stored for no condition to be processed.
The HT efficiently wet
desulphurizing technology was developed by Mr. Chen Minglou, the
general engineer, and the core technicians of Zhejiang Huate
Environmental Protection Equipment Industry Company, after five
years deeply research and scientifically calculating and analyzing.
This technology is based on wet lime-gypsum desulphurizing process,
combines with helical rotating-flow device and absorbs the
advantages of the traditional equipments, and can avoid the
insufficiencies of the former technologies, such as spray tower,
packing tower, ejector bubble tower, liquid column tower, turbulent
ball tower, venturi tube and porous tower, an so on.
The desulphurizing
equipment consists of inlet flue, main tower body, desludging box
and outlet flue. The main tower body is divided into two parts:
outer tank and inner tank. Between the outer tank and inner tank,
helical rotating-flow device, spray system and sputter-plate
overflow device are installed.
After being removed
dust, the gas enters the main tower body through the flue and
rises helically along the rotating board of the helical
rotating-flow device between the inner and outer tanks in the main
tower body. And then it meets and mixes with the film absorber
downstream that sprayed from the nozzle of the spray system.
SO2 in the
gas reacts with the absorber and produces CaSO4 and CaSO3.
Some of the desulphurizing liquid mixture with CaSO4 and
CaSO3 is trapped repeatedly by multiple reverse-angle
rotating-flow boards of the helical
rotating-flow device with the inertial force; the other of them is
thrown to the tower wall with the centrifugal force, and then is
pushed out from the sputter-plate overflow device and caught by the
film absorber on the tower wall.The desulphurizing liquid of the two
parts all falls into the bottom of the tower body with the gravity
and the helical force of each layer. The flue gas enters the inner
tank (container column) from the top of the tower body and falls
downward vertically. The remained little SO2 in the flue
gas goes on reacting with the few desulphurizer liquid drops and
produces CaSO4 and CaSO3.With the inertial
force and the gravity, the desulphurizing liquid with CaSO4
and CaSO3 falls to the bottom of the tower body. When the
flue gas enters the desludging box, CaSO4 and CaSO3
and water steam in it are again removed by the trapping device in
the desludging box. The purified flue gas after desulphurizing and
demisting finally goes through the outlet flue and discharged
through the chimney.
The desulphurizing
mixed liquid at the bottom of the tower body is discharged from the
water outlet to the water treatment device of the desulphurizing
circulating system. After treated, it can be used repeatedly. A
water seal arrangement is installed at the water outlet to separate
the flue gas in the tower from the atmosphere. A slope is installed
at the bottom of the tower to prevent CaSO4 and CaSO3
from depositing and scaling at the bottom.
Technical
characteristics of the desulphurizing equipment:Technical
characteristics of the desulphurizing equipment:
1．Low calcium-sulphur
ratio: calcium-sulphur ratio≤1.03；
2．Low liquid-gas ratio:
liquid-gas ratio≤0.8 l/m3；
3．High temperature of
discharged flue gas: temperature of flue gas≥63℃ ，no need to install flue gas temperature system (such as
GGH)；
4．Great demisting
function, low moisture content of discharged flue gas: moisture
content of flue gas≤2.54%；
5．Good performance of
antiscale: the system has a function of self-cleaning and can
avoid scaling；
6．High desulphurizing
rate: desulphurizing 100% of flue gas, desulphurizing rate≥95%；
7．Easy to overhaul and
maintain: no feeding and spray system, helical rotating-flow
device or trapping device of desludging box in the tower；
8．High utilization ratio
of the equipment: optimal system, low complication factor,
utilization ratio≥95%；the continuous normally-running time of the main
body≥3years；
9．Low resistance:
≤1000Pa. The system is designed intelligently and compactly;
there is no stuffing layer in the tower so the resistance is low；
10．The moisture rate of
the discharged flue gas is low and cannot scale or corrode the
flue and chimney；
11．Great adaptability:
this process can adapt to all types and tons of boilers
(especially to the boilers of 200-1200MW units) and the coal with
high, middle and low sulphur; under the condition that the key
parameters, such as current speed of flue gas and gas-liquid
ratio, etc., don’t change, the equipment can be ensured to run
stably；
12．Low total investment
of the project: the desulphurizing system generally only costs RMB
260 yuan/kw；
13．Low running costs: the
running costs only need RMB 0.002 yuan/kw/h；
14．Low degree of the rest
calcium sulfite in the desulphurizing by-product, in the condition
of not increasing the process of oxidizing device: the content of
calcium sulfite <8%，easy
to use and with low utility cost；
15．High utility rate of
desulphurizing circulating water: little drain of water in the
process, water circulating rate≥97.5%；
16．High degree of control
automation of the process.
The HT efficiently wet
lime-gypsum desulphurizing process is an improved localized
desulphurizing process. It simplifies the complex links of the
process and can reduce the project investment and optimize the
system. This technology will play an important role in promoting the
reform of the flue gas desulphurization of boilers in the thermal
power industry and easing the pressure on environmental protection
investment.
Hign
Efficiency and Wet Process of Desulphurization Technology of
HT Model
——China Environmental Protection Industry （2005.12） |
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