Green Sand Reclamation for Moulding Sand A Case Study Presented by: C Sathyamurthy, Vice President Aquasub Engineering, Coimbatore At 65th Indian Foundry Congress, Kolkata
Why Green sand reclamation? • Availability of sand • Quality of sand • Issues related to dumping of sand • Cost
S1 Sand Scrubber Installation Pics BEFORE
AFTER
Total Power consumption: 82.5 H.P. Total Air consumption: 40 c.f.m.
MACHINES PVT. LTD.
Reclaimed Sand System Process Flow
Sand Dryer with Existing Belt Conveyor from
Excess Sand Hopper
LPG Automatic Intermediate
hopper with Vibratory Feeder
Burner and Temperature Control
Sand Scrubber
& Deduster as per FATA Design
Desired Output < 1 % Moisture
Installed for manless operation
Pneumatic Conveyor to
Reclaimed Sand Hopper
Reclaimed Sand Hopper transfer output to
Return Sand System
Techno-Commercial Considerations - preinstallation Sand Balance Calculation
Quantity & Economics New Sand MT/ Month
600
New Sand MT/ Day
24
New Sand Cost Rs / MT
2,500
Disposal Cost Rs./ MT
50
Drying & Handling Rs / MT
0
Reclamation Cost Rs/ MT
1,000
Net Saving in Sand Cost Rs/MT
1,550
Reclaimed Sand Usage
75%
Reclaimed Sand MT per Month
450
Saving per Month in Rs.
6,97,500
Present Batch Capacity Return Sand Dead clay RS New Sand kgs Dead Clay NS DC Reduction Dead Clay S1 Net S1 Input to RS Net Dead Clay
100.00 95.00 2.40% 5.00 5.0% 0.50% 40% 1.440%
2.311
With Reclamation (S1) 100.00 91.25 2.40% 1.25 1.25% 0.50% 40% 1.440% 7.50 7.5% 2.304
Actual Usage Data from Dec 2015 to Dec 2016 •
Quantity of Sand Reclaimed
•
Average Utilisation Hours
•
Dead Clay Reduction Results (to make graph based on data collected)
•
•
At Output Rate – 2 t/hr to 1 t/hr
•
Dead Clay Reduction – 30% to 60%.
•
Output Rate set – 1.3 t/hr for 50% DC Reduction
Processing Costs @ 1.3 t/hr •
Energy – 20 kWh/MT of Reclaimed Sand @ Rs 8.0 = Rs 160/MT
•
LPG (To dry incoming sand) – 4.3 kg/MT (with 2-3% Moisture) @ Rs 60 = Rs 258
•
Total Cost of Reclaimed Sand = Rs 418/MT
•
Net cost of replacement of new sand = 2 x 418 = Rs 836/MT against Rs 1,000 considered in projections)
Benefits – Commercial & Environmental • New Sand Consumption Reduced in Moulding Sand - 15 per day / 425 MT per month • Reduction in Sand Disposal (net of fines removed) – 425 MT per month
• Estimated CO2 emission saved from Vehicular Emissions for 425 MT of Sand = 15 trips X 500kms = 7500 kms = Approx. 1500 litres of Diesel equivalent CO2 emissions • Return of Investment achieved • Investment – Rs 85 Lakhs • Saving – Rs 1,500/MT * 425 MT = Rs. 637000 per month
• ROI of 14 months