Aquasub green sand reclamation for moulding sand

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