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E. I. DU PONT DE NEMOURS & COMPANY 256 VANDERPOOL STREET NEWARK, NEW JERSEY
Stria! No ^-71-17
Copy No*
18
RETURN TO JACKSON LABORATORY
FILE ROOM
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NEWARK PLANT PIGMENT COLOR RESEARCH REPORT
LEAD MELTING AND OVERFLOW SYSTEM
Period Covered
JUNE 1969 - JUNE 1971
FILE: DATE:
121 6-30-71
NJ 14071
m 71-17
Copy No.
18
1. Numerical Pile 2. Research Office Pile 121 3. Newark Library Pile 121 4. M.Hunt,Pigments, Wilmington
5 W. S. S truve/J.Jackson/A.R.Hanke 6. R.H.Wetzel,Newport (cir. and Pile) 7. B.E. Jaife/E.F.Klenke/B.H. Perkins/Library 8* pJ.Monahan, Newark {Vital Records) 9. N.G.Fisher,Central Research Dept./Wilmington 10. Newark Library - for Central Report Index 11. Newark Library - for Central Report Index 12. W. J.McClure/R.H.Akins
13. R.Gedd/R.B .Horton 14. B.C.Hertz 15. Extra 16. Extra 17. Extra 18. Extra 19. Extra
NEWARK PLANT
PIGMENT COLOR RESEARCH REPORT
TITLE
LEAD MELTING AND OVERFLOW SYSTEM
PERIOD COVERED! JUNE 1969 -
qe.ikSUBMITTED BY: B. c. h eJr t z
E 1971
Date Submitted: 6/26/71
APPROVED BY:
Date Released: 6/30/71
ABSTRACT:
This report covers the design and installation of two electric lead melting furnaces and a heated molten lead overflow system in the lead nitrate area of Hie Newark
Plant. These facilities have replaced the single oil fired lead furnace and the manual ladling troughs.
K
JACKSON HIE
DUP050082763
INTRODUCTION Newark melts * 14,000,000 pounds of lead annually for the
subsequent manufacture of lead nitrate. The area used an oil fired furnace which consisted of a cast iron pot supported on a masonry fire box. An oil flame was distributed through a brick arch constructed below the pot in order to provide uniform heating and to minimize local hot spots.
The combination of external heating and the four ton lead load stressing the pot resulted in frequent pot failure. With failure the molten metal would seep down onto the brick arch and react with the refractory destroying it. A four to six day shut down would be needed to repair the damage. During this shutdown period no chrome yellows or Molybdate oranges could be made, after the lead nitrate in storage was consumed.
The lead, once molten, was hand ladled into an open metal trough. The operator manually transferred 20,000 pounds of molten lead per shift at instantaneous lift rates of 700 pounds per hour. Be was constantly exposed to the 1100*p. heat of the pot and the danger of spillage of the molten liquid.
Modernization and improvements of these facilities were investigated, and alternate methods selected and installed.
PATENT STATUS None
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SUMMARY AND CONCLUSIONS The oil fired furnace was an unreliable piece of equipment.
Past experience indicated a pot life expectancy of approximately 10.000,000 pounds of melted lead, or less than a single year's use (See APPENDIX).
Internal and external gas fired, internal resistance and induct ion furnaces were investigated as replacements. The lowest initial costs favored replacement with internal resistance heating units, and the lowest operating cost favored replacement with internal gas fired units. The relative simplicity of the electric resistance unit vs. the gas fired unit, as well as its ease of maintenance and ability to perform on a limited basis with the burnout of several elements, outweigh the added energy and heating element replacement cost.
Size and space limitations had precluded the possibility of constructing a second oil fired furnace in the lead shop area. The electric resistance and the internal gas fired furnaces could be designed to fit two units of the capacity of the oil fired furnace into the area.
Two electric resistance units were recommended as replacements and were installed in March of 1971* Startup of the first furnace was uneventful. The second furnace is serving as an installed spare.
A heated overflow system was designed and installed in November of 1969 as a demonstration prototype unit. The system was successful and remained in service for a year and a half, until the new furnaces were installed. At this time another heated overflow was designed and installed which overcame some deficiencies in the prototype unit. This system was started up in March, 1971 and has been operating satisfactorily.
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IN 8/35 1/37 4/37 2/38 4/43 12/45 5/47 4/48 12/48 4/50 12/50 7/51 5/51 11/52 9/53 3/54
5/55 11/55
2/58 7/58 9/60 7/62 1/64 6/64 12/65
T.RAD POP REPLACEMENT CYCLES MONTHS OPERATED 17 3 10 67 27 17 12 7 16 9 4 1 18 10 7 13 6 27 5 26 22 18 4.5 18 14 *- 3 -
APPENDIX
LEAD MELTED <*> 7.9 .9 3.0 24.3 9.7 10.3 10.6 4.9 10-0 10.2 3.8 1.4 18.4 11.1 6,3 13.0 7.8 25.5 4.2 23.6 18.7 15.9 4.0 15.9
DU P050082766
Lead Pot Replacement cycles
MONTHS IN OPERATED
2/67
11
1/68
6
7/68
ii
6/64
4
10/69
7
Appendix (Cent1d)
LEAD MELTED (MM.#)
-
10.3
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DUP050082767
ECONOMIC DATA
External Induction induction
Internal
Gas Fired
Htd
Htd
Internal Resistance
Unit
Commercial Du Pont Gas Fired
Htd
ID (2)
(3) (4)
(4)
Operating Unit
$9,045
$60,000
$10,000
$7,195
$5,900
Standby unit
9,045
60,000
10,000
7,195
5,900
Equipment Installa tion
18,090
120,000
18,000
17,960
11,800
Service Facilities
Gas 6,600
Electric
.
TOTAL
42,780
10.000 250,000
-
10,000 46,000
6,600
--
38,900
10.000 33,600
Ooeratincr Costs Based on cold Standby
Energy
$3,500
$6,180
$6,180
$3,500
Maintenance 1,300
4,800
3,000
1,010
Deprec 6%
3.560
15,000
2,750
2,330
TOTAL
7,360
25,980
11,930
6,840
$4,500 2,000 2,020 8,520
Gross ROI-% 12.6
0
0 31.5 Base
Investment cost for current appraisal study only not for project preparation.
1. American Gas Furnace company - Quote 2. inductotherm Company - Verbal quote
3. Chambers Works Design - John Branscome estimate
4. C. M. Kemp company - Quote
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DUP050082768
Design Data; Induction Heating - 120 watts per foot of pipe at 60 cycle 110 volts to beat pipe to 450c using one turn per inch and three inches of magnesium Oxide insulation*
- 3 KVA transformer "Buck or Boost Transformer" GE model #9T5M113 2 volts per foot of pipe at 60 amps*
RECOMMENDATIONS The high heat loss from the open top of the lead pot would
favor installation of an insulated cover. This would minimize holding losses and reduce energy costs.
Molten lead should be ladled from the operating furnace into the standby furnace to a level of four inches. This would cover the heating elements and facilitate an emergency startup of the second unit.
REFERENCESi 1. Drawing #d-39820, The C. M. Kemp Mfg* Co. 2. Letter from J. W, McNees, E.S.D. to Barry Hertz dated July 28, 1970. 3. Project No. 7820
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