Ice Condensation Vacuum Systems
Karl Tomas Eriksson • •
German Technology meets ASAGA World Congress on Oils and Fats and 31st Lecture series Rosario – Argentina - Oct. and Nov. 2015
Traditional Multistage Ejector System with Cooling Tower 1 Booster (stage 1) 2 Booster (stage 2) 3 Main direct contact condenser 4 Ejector (stage 3) 5 Inter condenser 6 Ejector (stage 4) 7 Seal tank 8 Cooling water pump I 9 Cooling tower 10 Cooling water pump II
Low cost system but polluted cooling water Maintenance free (no risk of pollution in the condensers) Cooling tower must be cleaned time to time Air pollution
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11 Motive steam 12 Fresh water (cooling tower) 13 Bleed (cooling tower) 14 Overflow of fatty water 15 Draining 16 Gas outlet 17 Stripping steam from deodorizer 2
Alkaline Vacuum System (Chilled Water) Low energy consumption Low amount of waste water No air pollution Save operation
1 2 3 4 5 6 7 8 9A 9B 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
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Booster (stage 1) Main direct contact condenser Ejector (stage 2) Inter condenser Liquid ring vacuum pump Fat separator (buffer tank) Circulation pump pH-control unit Plate heat exchanger (in operation) Plate heat exchanger (stand by) Brine pump Compensation vessel Coolant compressor (chiller) Cooling tower pump Cooling tower Motive steam Heating steam Stripping steam from deodorizer Condensate Circulation water Chilled water Total over flow Caustic soda (NaOH) Gas outlet Fresh water (cooling tower) Bleed (cooling tower)
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Ice Condensations Vacuum System Most efficient system for large capacities Lowest energy consumption Minimum amount of waste
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Ice condenser I Ice condenser II Melting vessel Condensate pump Ejector stage1 Ejector stage 2 Air evacuation condenser Liquid ring vacuum pump Gas separator (Liquid ring vacuum pump) Re-cooler (Liquid ring vacuum pump) Refrigerant compressor Expansion valve Priority vessel Refrigerant separator Evaporative condenser
16 17 18 19 20 21 22 23 24 25
Cooling water Motive steam Stripping steam from deodorizer Gas outlet (Liquid ring vacuum pump) Over flow (liquid ring vacuum pump) Overflow (melting vessel) Heating steam Condensate Fresh water (soft water) Bleed (evaporative condenser) 4
Operation Cycle and step sequence of the Ice Condensation System Ice Condenser I on melting Ice Condenser II on loading
SWITCH OVER Ice Condenser I on loading Ice Condenser II on loading
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Ice Condenser I on pre-cooling Ice Condenser II on loading
Ice Condenser I on loading Ice Condenser II on melting
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Example of Installation of an ICE Condensation Vacuum System Ammonia Separator
Air Evacuation Unit
ICE Condenser Block
Liquid ring Vacuum Unit
Melting Vessel
Refrigerant Compressor Footer
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Main Advantages of an Ice Condensation Vacuum System significant energy saving by high efficiency far less waste water will be produced nearly no air pollution will be produced minimum space requirement (skid mounted units) R e frgi e ran t S epa ra ot r
non barometric installation newest technology with computer controlled operation
Ice C onden se r
experience by various installation world wide since 1988 S et am Je tE ej c ot r V a cuum G roup qi u di R ni g V a cuum P um p
C onden sa et M e ltni g V e sse l P um p
R e frgi e ran t C om p re sso r
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P ro ce ss V e sse l
R e frgi e ran t C onden se r
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ICE Condenser Vertical vs. Horizontal installation
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Rising film
Rising film
Falling film
Rising film
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Typical design of a Körting ICE Condenser CROSS FLOW
Air evacuation
Melting steam
Melting steam
NH3 out
NH3 in
Process flow
Process flow
Condensate Footer
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Controlled and Uncontrolled Ice Building View into a Körting ICE Condenser during loading Controlled, constant and smooth ice building due to the right condition, cycle time and operation
View into an Condenser from our competitor during loading Uncontrolled and heavy ice building due to over loading-
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Ice Building – Loading Cycle Time Chilling capacity should be design for loading and peak conditions.
Chilling capacity
Ice Condenser
100 %
==> Avoid Vacuum fluctuation !
85 % Safety margin Insolalation losses
65 %
Loading
Koertig design for 60 minutes loading cycles (3.5 mm ice layer) 5
30
60
time (minutes)
Longer loading times (> 2 hours) is not an advantage! ==> Pressure drop and electrical power will dramatically increase !
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Driving Forces for Koerting developing Ice Condensation vacuum systems Highest possible plant availability and reliability
Minimum Energy / Utilities Consumption
• 02 high quality valves at each suction steam condenser inlet; • 02 condenser inlets – Process and Heating Steam; • Horizontal condensers • Natural flow, without pumps – ammonia and heating steam cycles; • Surface Area – 2 x 100% • Condenser pipes; – Configuration; – Fixation (no welding on process side) • Position of Air Evacuation Outlet
• • – – – •
•
•
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Optimal Heat Transfer - Ice Layer and Cycle Time Lowest possible Pressure Drop; 02 Process and Heating Steam Inlets; Cross Flow Condensers Natural flow - ammonia and heating steam cycles; Optimal Melting - Fast and energy efficient without necessity for additional pumps Optimal Motive Steam Consumption Less Cooling Water Less Waste Water Low electrical energy consumption Low pressure drop / thinner ice layer / shorter cycles
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Comparison of the Various Systems ALKALINE CHILLED WATER
ICE CONDENSATION
Comparison of the Various Systems
∑ Motive Steam consumption
=
235 kg/h
∑ Cooling Water consumption
=
42 m³/h
∑ Motive Steam consumption
=
678 kg/h
∑ Cooling Water consumption
=
185 m³/h
(approximate daily production 600 t)
∑ Electrical Power consumption = 165 kW
∑ Electrical Power consumption =
∑ Motive Steam consumption
=
2597 kg/h
∑ Motive Steam consumption
=
3000 kg/h
∑ Cooling Water consumption
=
425 m³/h
∑ Cooling Water consumption
=
450 m³/h
210 kW
kg/ stripping steam + 10 kg/ air + 4 kg/ FFA, 80°C Design Data:= 0,489 250 ∑ Waste Water consumption m³/h ∑ Waste Water h h consumption h= 0,935 m³/h SURFACE 1,5 mbar at inlet to the vacuum system; ALKALINE motive steam pressure 10 bar abs / saturatedCONDENNORMAL WATER SATION cooling water inlet temperature 30 °C; wet bulb temperature 21 °C
∑ Electrical Power consumption = ∑ Waste Water consumption
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40 kW
= 2,854 m³/h
∑ Electrical Power consumption = ∑ Waste Water consumption
13 kW
= 3,257 m³/h
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Comparison of the Various Systems ALKALINE CHILLED WATER
ICE CONDENSATION
∑ Motive Steam consumption
=
235 kg/h
∑ Cooling Water consumption
=
42 m³/h
∑ Motive Steam consumption
=
678 kg/h
∑ Cooling Water consumption
=
185 m³/h
∑ Electrical Power consumption = 165 kW
∑ Electrical Power consumption =
∑ Waste Water consumption
∑ Waste Water consumption
= 0,489 m³/h
= 0,935 m³/h
SURFACE CONDENSATION
ALKALINE NORMAL WATER
∑ Motive Steam consumption
=
2597 kg/h
∑ Cooling Water consumption
=
425 m³/h
∑ Electrical Power consumption = ∑ Waste Water consumption
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210 kW
40 kW
= 2,854 m³/h
∑ Motive Steam consumption
=
3000 kg/h
∑ Cooling Water consumption
=
450 m³/h
∑ Electrical Power consumption = ∑ Waste Water consumption
13 kW
= 3,257 m³/h
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Comparison of the Various Systems Design Data :
250 kg/h stripping steam + 10 kg/h air + 4 kg/h FFA, 80 °C 1,5 mbar at inlet to the vacuum system motive steam pressure 10 bar abs / saturated cooling water inlet temperature 30 °C wet bulb temperature 21 °C
Cost Comparison for 8.250 operation hours / year
ICE
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ACL (cold)
ACL (warm)
Surface condensation
Steam costs (US $/t) / year
25
51.975
138.600
535.631
618.750
Re-cooling costs for the cooling water (Cent/m³) / year
10
33.000
174.900
350.625
378.675
Electrical power cost (Cent/kW) / year
10
134.475
181.500
33.000
8.250
Effluent costs (US $/m³) / year
4
16.698
30.657
94.182
107.481
Caustic soda costs 25% (Cent/kg) / year
8
0
1.980
1.980
1.980
Operation costs / year ( in US $ )
236.148
527.637
1.015.418
Difference / year ( in US $ )
878.988
587.499
99.718
Equipment price ( in US $ )
1.000.000
410.000
360.000
Difference / year ( in US $ )
675.000
85.000
35.000
Saving after 1 year
203.988
502.499
64.718
Saving after 2 years
1.082.976
1.089.998
164.436
Saving after 3 years
1.961.964
1.677.497
264.154
1.115.136
325.000
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Koerting do Brasil Ejetores e Equipamentos de Vácuo Ltda. Rua Adib Auada 35 Bloco B - Sala 110 06710-700 Cotia – SP Tel.: +55 11 4321-2745
[email protected]
www.koerting.de