Arp Training manual

1. CRM Complex
Acid Regeneration Plant
Training Manual
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2. INTRODUCTION
The Regeneration of the used Pickling Acid
The hydrochloric acid used in the pickling process is thermally treated in the
regeneration plant for the purpose of recovery and reuse in the pickling process.
Roughly, the plant is divided into the following sections;
• The rector in which the iron chloride is transformed into iron oxide and gaseous HCl
• The cyclone, incl. dust recirculation
• The venturi, in which the hot gases are cooled down from approximately 850’C to
100’C during this process the pickling acid is strongly concentrated due to
evaporation of water
• The separator in which the waste gases coming from the venturi liquid
• The absorber in which the hydrochloric acid is recovered by absorption of the
gaseous HCl in water
• The fan F-V-31 with the fume stake which sucks of the gases developed in the
reactor and keeps the entire system below atmospheric pressure. The residual inert
gases are led through the fume stake into the atmosphere
• The venture F25 with separator B26 in which a final treatment of the waste gas is
achieved.
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3. LINE DIAGRAM
K11
Nomenclature
Nomenclature
K11
A4
A4
K38
B26 F5
F5
F25 K38 F3
B26 F25 F3 C1
C2
K8
K8
B7
B7
V31
V31
C1
C2
C1,C2 –Reactor V31 –Exhaust fan
V31 - Exhaust fan
C1,C2 - Reactor
F3 –Cyclone K38 –Control valve valve
F3 -Cyclone separator K38 - Control
A4 –Gas duct F25 –Venturi scrubber V30
A4 –Venturi
F5 - Gas duct F25 - Venturi scrubber
B26 –Scrubber
F5 - Venturi B26 - Scrubber
B7-Separator
B7- Separator K11-Chimney
K11- Chimney
K8 - Absorber
K8 -Absorber V30 -Combustion Blower Blower
V30 - Combustion
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4. BASIC PROCESS
The oxides which result from the oxidation with oxygen while the
material is being hot rolled are an obstacle to the subsequent treatment and must
be eliminated.
In this case the oxides are eliminated by pickling with a solution
of hydrochloric acid.
The oxides arising during the oxidation process are transformed
by the effects of HCl into FeCl2.
Reaction Equation
The chemical reaction during the pickling process can be
illustrated with the following reaction equation:
Fe2O3 + 6HCl = 2FeCl3 + 3H2O
FeO + 2HCl = FeCl2 + H2O
2FeCl3 + H2 = 2FeCl2 + 2HCl
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5. LINE SPECIFICATIONS
Specifications
Rinse water to Absorber
80- 90 C Rinse water to Absorber
-5 to-10 mbar
-150 to-180 mbar
-150 to-180 mbar 800- 850 C
-5 to-10 mbar
100- 105 850- 870 C
50 mbar
50 mbar
C
-80 to-90mbar
-80 to-90 mbar 400- 750 C
870- 890 C
1440 g/lit
Acid to Reactor Oxide bed
Scrubbercirculation
Scrubber circulation oooooooooooo
oooooooooooo
Regenerated Acid
Regenerated Acid
Venturi Circulation
Whirl Air
Whirl Air Natural
Gas
Natural Gas
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6. TECHNICAL SPECIFICATIONS
• Waste Acid input : 4000 Ltr/hr
• Oxide Production : 700 Kg/hr
• Regenerated Acid Production : 5000 Ltr/hr
• Exhaust Fan V31 : 19000 M3/hr
• Air Blower V30 : 6000 M3/hr
• Venturi Circulation Pumps P32/P33 : 90 M3/hr
• Scrubber Circulation Pumps P34/P35 : 30 M3/hr
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7. PROCESS DESCRIPTION
Plant consists of following main equipments:
• Reactor with cyclone separator
• Venturi F5
• Absorption Tower
• Fan V31
• Venturi F25
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8. THE REACTOR AND THE CYCLONE SEPERATOR
Oxide
Oxide
HCL Fumes
HCL Fumes
870- 890 C
Oxide bed
oooooooooooo
oooooooooooo
oooooooooooo
oooooooooooo
oo
oooooo
oooooooo
By
By product
product
Fe2O3
Fe2O3
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9. THE REACTOR AND THE CYCLONE SEPERATOR
The fluidized bed in the reactor consists of particles of iron oxide in
turbulent state by the combustion gas. In to this fluidized bed, the
concentrated venturi liquid is pumped
through a titanium lance.
As a result of high temperature about 850 C the FeCl2 splits up into
Fe2O3 and Hcl. Thus the reverse of pickling
reaction takes place in the reactor.
2FeCl2 + 2H2O +1/2 O2 ------- Fe2O3 + 4Hcl
About 95% of this reaction takes place on the surfaces of the oxide
particles present, and only approx. 5% in the gas phase in between the
grains.
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10. THE REACTOR AND THE CYCLONE SEPERATOR
While the iron oxide reacting on the surface of the oxide particles, they
form fine oxide dust which is carried out of the reactor with combustion gasses
in the cyclone this dust is recovered and lead back to the reactor by means of
dust return pipe.
This formed iron oxide is discontinuously drawn off from the reactor as
Byproduct.
Due to this the amount of the material and thus the height of the whirling
bed is kept constant.
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11. THE VENTURI F5
• The hot reaction gasses drawn out of the
Rinse water
Rinse water
reactor at a temperature of 850 C are cooled in
the venturi to approx 100 C.
850 C
F5 • This cooling is achieved by the evaporation of
Evaporation
Evaporation water out of the venturi liquid, also the fine dust
100 C passing the cyclone also washed out by means
of venturi circulation.
K8
Hcl gas
Hcl gas B7
Density 1440 g/l • The venturi liquid needed for cooling is taken
Density 1250 g/l from Separator B7 by means of pumps
Regn Acid
Regn Acid P32,P33. as a result of evaporation the venturi
liquid becomes very concentrated.
P32 • Adding rinse water sets density of 1440 g/lit in
P33 the venturi circulation system.
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12. THE VENTURI F5
• Adding rinse water sets density of 148 Kg/CM3 in the venturi circulation system.
• A split system is taken out of this Venturi circulation system and conveyed to
reactor C1.
• The waste stacked in the storage station is pumped by means of pumps into
receiver vessel B15. This receiver vessel communicates with the separator B7.
Any reduction in the level of the separator as a result of the consumption of
Venturi liquid in reactor C1 in thus automatically equalized by the addition of
waste acid.
• Any excess waste conveyed to receiver vessel B15 flows back into the
appropriate waste acid storage tank.
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13. ABSORBER K8
• The hydrochloric acid present in the waste gas stream is scrubbed out in
absorber K8.
• To accomplish this, the upper part of the absorber is impinged with city water
which then flows through the absorber from top to bottom countercurrent to
the flow of gas.
• In doing so, the hydrochloric acid carried in the gas flow is washed out.
• Then the recycled regenerated acid flows from the bottom-most of the
absorber into the acid storage station.
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14. THE EXHAUST FAN V31
The waste gas out of the absorber K8
are drawn Off by the exhaust fan V31 and blown
K11
K11
out to the Venturi F25, To avoid build up on the
titanium Impeller. Water is continuously sprayed
over it.
K38
K38
B26
B26 F25
F25
V31
V31
P34
P35
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15. THE VENTURI F25 & OXIDE COOLING
TABLE & VERTICAL OXIDE CONVEYOR
• After the fan V31 the waste gases reach the venture F25 in which the waste
gases are mixed with water and thus the remaining HCl is removed out of the
waste gases.
Oxide Cooling Table V50
• Hot oxide is drained and cooled with cooling Table having water cooled
jackets and VFD motors to remove the oxide generated in the reactor.
Vertical oxide conveyor
• Cooled oxide from V50 is transported to oxide storage bin by vertical
spiral
conveyor driven by two unbalanced motors. From oxide bin cooled oxide is
safely filled in dumper and sent for recycling.
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16. THE TANK FARM & SUMP
From ARP
From ARP
To ARP
RW WPL RA Regn Acid Regn Acid RA TO PKL 1 1
RA TO PKL
10KL 10KL 10KL To ARP Regn Acid
Pkl 1
Pkl 1
Pkl 1
Regn Acid
85 kl kl
85 Pkl85 kl
1
85 kl
Regenerated
Acid pkl 2
Regenerated
Acid pkl 2
150 kl
150 kl
RA TO PKL 2
RA TO PKL 2
Rinse water Waste pickle Waste pickle Waste pickle
Waste pickle Waste pickle
Acid 2 Acid 1
Pkl 1 & 2 Acid 3 Waste pickle
Rinse water Acid 3 Acid 2 Acid 1
150 kl 150 kl kl
150 150kl
150 kl 150 kl
Acid 1 & 2 150 kl
150 kl
WPL From PKL 2
RW TO PKL 2 WPL From PKL 1
WPL From PKL 2 WPL From PKL 1
RW From PKL 2
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17. THE TANK FARM & SUMP
• ARP reserves the total capacity of 950 kl in its tank farm, which consists of
160 kl Rinse water, 460 kl Waste pickle Acid and 330 kl Regenerated acid.
• The tank farm is safely designed and located at -2 mtr level and having safe
Drainage system to meet Environmental and safety requirements.
• Waste water from ARP and Tank farm are collected in the sump pit and is
pumped to Effluent Treatment plant safely.
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18. Thank you
Compiled by :
RAJIV ARORA