Multiple Effect Evaporator (MEE)
Effluent treatment for Strong Stream (for COD more than 10000 mg/lit):
The incoming effluent would be allowed to get collected in collection cum
Equalization tank. Required chemical treatment would be given using for pH
adjustment. The sludge from chemically treated effluent would be drained and
the supernatant will pass through Multiple Effect Evaporator. The condensate
from Multiple Effect Evaporator would be used in cooling tower of the quality is
acceptable. The reject from MEE would be incinerated in Solid cum liquid
incinerator.
The strong stream shall be given thermal treatment in Multiple Effect Evaporator
(MEE). the required pre-treatment for separation of Suspended solids shall be as
follows:
The strong stream shall be stored in one collection tank, the dosing of Poly
Electrolyte for coagulation and settling shall be done in zig-zag channel and
allowed to get settled in Settling tank. The supernatant of settling tank shall be
fed to MEE for evaporation. The sludge separated at bottom shall be sent to
TSDF site.
Tank size
Collection tank:
15 m3
Settling tank: 1.5 x 1.5 X 1.5 m3
INCINERATION SYSTEM:
5.4.1 PROCESS DESCRIPTION:
Bogie type pyrolizer is stationary type and the solid waste is charged in
batch wise into the bogie. The pyrolizer is operated at a temperature of 600
– 850 deg C and air is introduced in later stage for complete combustion of
the waste.
The required auxiliary energy for incinerator temp is maintained by
automatic fuel burner & is controlled through a temperature controller.
The aqueous waste is atomized through specially designed atomizer in to
the m a i n c ombus tion chamber. The te m p e ra t u re o f t h e MC C is
maintained at 800 – 900 deg C. Required energy for incinerator temp is
maintained through fuel burner, which is controlled through temperatures
controller for better fuel efficiency.
Post combustion chamber is refractory lined fired furnace. Fuel burner is
installed in the chamber to supplement required energy to raise the
temperature of the gas stream to achieve complete destruction of
combustible components or to enhance conversion of the components. The
flue gas from Bogie type pyroliser & MCC is re-combusted in the
combustion chamber at 1100 - 1200°C in excess air condition and required
retention time. Air is provided to the chamber to achieve complete
destruction.
Quencher is a n o p e n c o l u m n d i r e c t c o n t a c t c o u n t e r c u r r e n t
h e a t exchanger. Gas is introduced from the bottom and move upwards
while the w a t e r i s i n j e c t e d f r o m t o p a t o m i z e d d r o p l e t s . When t he
wa t e r evaporates, the heat of vaporizing the water is obtained at the
expense of the hot combustion gas, resulting in a reduction in the gas
temperature. The un-vaporized water reaching the bottom of the tower is
re-circulated by pumping back to the Quencher. The quencher is
considered as spray tower and spraying of water droplets in to a polluted
gas stream resulting in the removal of highly soluble gases and
particulate matters. The evaporative loss of water from the circulation tank
is compensated by makeup water addition. This alters the particulate
properties by raising surface conduction and increasing inter-particle
bonding, thereby enhancing t h e c o l l e c t i o n o f d u st a n d t ra ce
e le m e n t s in p a rt icu la t e devices.
The cooled flue gases from quencher are then passed through a Venturi.
Venturi is a pressure jet type device. Incinerator exhaust gas entering in to
the Venturi is accelerated to high velocity at the constricted area (throat)
and the scrubbing liquid is introduced at the throat in fine form. The high
velocity of the gas causes breaking of droplets into fine filaments
and droplets, which allow a large surface area.
The droplets accelerate in the throat section and the droplets and
particles are impacted against the slow moving droplets. Venturi itself is
only a gas conditioner and is followed by a separator. The liquid gas
mixture is their directed to separator to separate dense wet particles and
liquid droplets in the gas stream.
Packed B e d S c r u b b e r is vessel filled with randomly oriented packings,
Ranching Rings. Gaseous contaminants are removed by gas absorption
process by intimate gas/liquid contact. The Scrubbing liquid is fed into the
top of the vessel, with gas flowing in counter current mode. As the liquid
flows through the bed, it wets the packing material and provides interfacial
surface area for mass transfer with the gas phase.
On the Packed Bed Scrubber, the scrubbing liquid (NaOH Solution) wets
the gas rise through the column making close contact with the down flowing
liquid little gas. The soluble gases are scrubbed from the mixture of gases
by liquid. In the absorption of gases, caustic soda reacts directly with
gases as the gas approaches the liquid interface it dissolves and reacts with
caustic soda.
The support plate at the bottom of the bed of packing is designed to have
least resistance and maximum flow area and to have better distribution of
gas across packing bed and draining liquid completely.
The distributor mounted on top of the packed bed is designed to provide
uniform –irrigation of the packing.
Flue gas from the packed bed scrubber is passed through mist eliminator for
mist removal and flue gases are released into the atmosphere through an
I.D. Fan & Chimney.
I.D. Fan is the heart of the system, which maintains draft in the system
to overcome the flow resistance & prevent obnoxious gas leakage in the
plant operating area.
The system is provided with chimney to discharge the gas with good
dispersion characteristics.
5.4.2 INCINERATOR PROCESS FLOW DIAGRAM:
5.4.3 DESIGN ADEQUACY OF INCINERATOR :
Sr.
Incineration Aspect
No.
1 Incinerator capacity
2 Characteristics of Waste
Aqueous Waste
Solid Waste
3
4
Storage of Hazardous Waste
Waste feeding system
Solid waste feeding
Aqueous Waste feeding
5
Primary Chamber
Design
Remark
Solid waste – 50 Kg/hr, Aqueous waste – 250 lit/hr
--
75% Water, 3-5% Organic, 10-20% inorganic salt, Calorific Value300 Kcal/kg
Activated Carbon/Organic sludge/Packing material etc., Calorific Value4000 Kcal/kg
3 MT
--
Bogie type pyroliser for incinerating solid waste. Solid waste will be fed in
the bogie batchwise.
Aqueous waste is fed through specially designed automizers into the main
combustion chamber.
Type : On/OFF type, monoblock
Size -2200 mm dia X4000 mm long
Volume : 6 m3
Type of fuel : LDO/HSD
Fuel consumption rate : 40-50 ltr per hour
Fuel calorific value : 9600 Kcal/kg
Temp. : 800 – 9000C
Refractory lining : 115mm thk – Insulation Brick
230mm thk – Fire Brick
Burner details:
Make : Mc Cellend
Nos of burners :
Burner cap.: 20-60 X10 4– MCC
--
---
-Adequate
ADEQUECY OF INCINERATOR :
Sr.
No.
Incineration Aspect
Design
Blower Details:
No. of Blowers
5
Secondary
Chamber
(Proposed)
Capacity of Waste Blower
Combustion Temperature
MOC
Adequate
:
:
:
:
1 (common for MCC, PCC and Bogie
Pyroliserl)
2500 m3/hr 5 HP
1100 – 12000C
MS + Refractory lined
:
50 mm thk – calcium Silicate blocks
115mm thk – Insulation rick
230mm thk – Fire Brick
:
:
1, ON/OFF type, monoblock
30 X 104 - PCC
:
:
1 (common for all)
2500 m3/hr 5 HP X 2900 RPM
:
:
:
LDO/HSD
20-30 ltr per hr
20000 Lit.
Refractory
Burner Details:
No of Burner
Burner Capacity
Blower Details:
No. of Blowers
Capacity of Waste Blower
Fuel Details
Type of Fuel
Fuel Consumption Rate :
Fuel Storage Capacity
Shell Volume:
Shell Inside Volume:
Size:
Residence Time :
Remark
9 m3
2600 mm dia X 4600 mm
min. 2.5 sec
Adequate
ADEQUECY OF INCINERATOR :
Sr.
Incineration
No.
Aspect
6 Pollution control
devices
Design proposed
Type pollutants expected: - HCl/ SO2/ NOx/ particulate matter
Stack Details:
Stack Height
: 30m
Top dia.
: 550 mm
Flue gas temp. :
: 70-750C
Reservoir / Quenching tank:
Size
: 0.6 m dia X 0.9 m height
Type
: CYLINDRICAL
Volume
: 5000 Lit.
MOC
: PP/FRP
Ventury Scrubber:
Type
: Pressure jet venturi
Throat Venturi Dia
: 300 mm
MOC of Venturi
: MS + Refractory
Refractory
: Acid resistance bricks
Pressure drop
: 250--350 mmwc
Ventury water tank :
3 m. X 3 m. X 5 m.
ID Fan:
Fan type
: induced draft ,Centrifugal, 2 Nos.
Fan cap.
: 9000 m3/hr & 650mm water gauge pressure
Motor HP
: 50HP
Remark
Adequate
Adequate
Adequate
ADEQUECY OF INCINERATOR :
Sr. Particulars
No.
6 Pollution
control
devices
7
8
9
Design proposed
Packed Bed Scrubber:
Overall size of PBS
M.O.C
Pressure drop
Packing
Packing height
Scrubbing media
Scrubbing temp
Circulation Tank
Circulation tank
Nozzle MOC
Circulation Pump
Remark
Adequate
:
:
:
:
:
:
:
:
:
:
:
2000 mm dia X 5500 mm
MS internally refractory lined
100-115 mmwc
1 ½” rashing rings
1000 mm +400 mm
Water + Caustic
70-750C
5 M3
MS internally refractory lined
SS316L
Type-Vertical glandless
Capacity-20 m3/hr, MOC- PP, Motor-7.5 HP
Pressure--2 kg/cm2
Ash/slag
Collection, storage, transportation by registered vehicles and final disposal to Approved
management TSDF site. Storage area 3.0 m X 3.0 m shed of 4.0 m height
Monitoring
Stack gas monitoring/recording system for CO/SO2/NOx / HCl/ Opacity
and online
display
requirement
Quench /
Quencher /Scrubber effluent can will be sent to effluent treatment plant for further
scrubber
treatment.
liquid
Management
Adequate
Adequate
Adequate