Evaluation of Oxyfuel Gas Cutting Gases

Evaluation of Oxyfuel Gas Cutting Gases ————————— July 14, 2014 ————————— EWI Project No. 55272CSP Submitted to: Magnegas Tarpon Springs, Florida

Report

Project No. 55272CSP

on

Evaluation of Oxyfuel Gas Cutting Gases

to

Magnegas Tarpon Springs, Florida

July 14, 2014

Nick Kapustka EWI

1250 Arthur E. Adams Drive Columbus, OH 43221

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Contents

Page

1.0 Introduction .......................................................................................................................... 1

2.0 Objectives ............................................................................................................................ 1

3.0 Experimental Procedure ....................................................................................................... 1

4.0 Results ................................................................................................................................. 3

5.0 Discussion............................................................................................................................ 6

6.0 Conclusions ......................................................................................................................... 8

7.0 Future Work ......................................................................................................................... 9

8.0 Reference ............................................................................................................................ 9

9.0 Disclaimer ............................................................................................................................ 9

Tables

Table 1. Torch Type and Tip Type Used to Make the Deliverable Cuts for Each Fuel Gas/Plate Thickness Condition ................................................................................ 10

Table 2. Gas Pressures, Flow Rates, Travel Speed, and Total Gas Consumption for the Deliverable Cuts Made for Each Fuel Gas/Plate Thickness Condition (Gas Consumption Does Not Account for the Preheat Time) ........................................... 11

Table 3. Surface Depression Measurements for the Cut Surfaces of Deliverable Cuts Made on 2-in. Plate ................................................................................................. 12

Table 4. Preheat Data for Deliverable Cuts Made for Each Fuel Gas/Plate Thickness Combination ............................................................................................................ 13

Table 5. Gas Pressures, Flow Rates, Travel Speed, and Total Gas Consumption for the Best Cuts Made Using Magnegas Products and Cutting Tips Designed for Propylene Gas (Harris 6290-NXP Type Tips) .......................................................... 14

Table 6. Cutting Orifice Diameters for One Tip for Each Combination of Tip Type and Size .. 14

Table 7. Comparison of the Flow Rate and Travel Speed Values Listed in the AWS Handbook Volume 2 for Cuts Made With Acetylene and Propane With the Values for Deliverable Cuts Made During this Project ......................................................... 15

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Contents (Continued)

Page Figures

Figure 1. Cutting Equipment, Positioning System, and Cutting Table ..................................... 16

Figure 2. Allicat Model M-100 SLPM-D/SM Flow Meters ........................................................ 16

Figure 3. Photo Showing the Feeler Gage and Straight Edge Used to Measure Maximum Depth of Surface Depression for Deliverable Cuts Made on 2-in. Steel Plates ........ 17

Figure 4. Photo Showing the Surface of the 1-in. Steel Plates Cut During this Project ........... 17

Figure 5. Photo Showing the Surface of the 2-in. Steel Plates Cut During This Project Using Acetylene ...................................................................................................... 18

Figure 6. Photo Showing the Surface of the 2-in. Steel Plates Cut During this Project Using Magnegas 1, Magnegas 2, and Propane ....................................................... 18

Figure 7. Photos of a Deliverable Cut Made Using Acetylene on a 1-in. Steel Plate (Trial ACE 12, top corner is shown on the left, cut surface is shown on the right) .... 19

Figure 8. Photo of Deliverable Cut Made Using Acetylene on a 1-in. Steel Plate (Trial ACE 12, straight edge placed on cut surface to show flatness) ...................... 19

Figure 9. Photos of a Deliverable Cut Made Using Magnegas 1 on a 1-in. Steel Plate (Trial MG1-06S-A, top corner is shown on the left, cut surface is shown on the right)19

Figure 10. Photo of Deliverable Cut Made Using Magnegas 1 on a 1-in. Steel Plate (Trial MG1-06S-A, straight edge placed on cut surface to show flatness) ................ 20

Figure 11. Photos of a Deliverable Cut Made Using Magnegas 2 on a 1-in. Steel Plate (Trial MG2-09S-A, top corner is shown on the left, cut surface is shown on the right) ........................................................................................................................ 20

Figure 12. Photos of a Deliverable Cut Made Using Magnegas 2 on a 1-in. Steel Plate (Trial MG2-09S-A, straight edge placed on cut surface to show flatness) ................ 20

Figure 13. Photos of a Deliverable Cut Made Using Propane on a 1-in. Steel Plate (Trial PRP-10-A, top corner is shown on the left, cut surface is shown on the right) ........................................................................................................................ 21

Figure 14. Photos of a Deliverable Cut Made Using Propane on a 1-in. Steel Plate (Trial PRP-10-A, straight edge placed on cut surface to show flatness) ................... 21

Figure 15. Photos of a Deliverable Cut Made Using Acetylene on a 2-in. Steel Plate (Trial ACE-12, top corner is shown on the left, cut surface is shown on the right) .... 21

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Page

Figure 16. Photos of a Deliverable Cut Made Using Acetylene on a 2-in. Steel Plate (Trial ACE-12, straight edge placed on cut surface to show flatness) ...................... 22

Figure 17. Photos of a Deliverable Cut Made Using Magnegas 1 on a 2-in. Steel Plate (Trial MG1-8S-A, top corner is shown on the left, cut surface is shown on the right) 22

Figure 18. Photo of a Deliverable Cut Made Using Magnegas 1 on a 2-in. Steel Plate (Trial MG1-8S-A, straight edge placed on cut surface to show flatness) .................. 22

Figure 19. Photos of a Deliverable Cut Made Using Magnegas 2 on a 2-in. Steel Plate (Trial MG2-13S-A, top corner is shown on the left, cut surface is shown on the right) ........................................................................................................................ 23

Figure 20. Photo of a Deliverable cut made using Magnegas 2 on a 2-in. Steel Plate (Trial MG2-13S-A, straight edge placed on cut surface to show flatness) ................ 23

Figure 21. Photos of a Deliverable Cut Made Using Propane on a 2-in. Steel Plate (Trial PRP-05A, top corner is shown on the left, cut surface is shown on the right) . 23

Figure 22. Photo of a Deliverable Cut Made Using Propane on a 2-in. Steel Plate (Trial PRP-05A, straight edge placed on cut surface to show flatness) .................... 24

Figure 23. Photos of the Best Cut Made on 1-in. Steel Plate Using Magnegas 1 and a Tip Designed for Propylene (Trial MG1-07, top corner is shown on left, cut surface is shown on right) ........................................................................................................ 24

Figure 24. Photo of the Best Cut Made on 1-in. Steel Plate Using Magnegas 1 and a Tip Designed for Propylene (Trial MG1-07, straight edge placed on cut surface to show flatness) ......................................................................................................... 24

Figure 25. Photos of the Best Cut Made on 1-in. Steel Plate Using Magnegas 2 and a Tip Designed for Propylene (Trial MG2-16, top corner is shown on left, cut surface is shown on right) ........................................................................................................ 25


Figure 27. Photos of the Best Cut Made on 2-in. Steel Plate Using Magnegas 1 and a Tip Designed for Propylene (Trial MG1-11, top corner is shown on left, cut surface is shown on right) .................................................................................................... 25


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Page

Figure 29. Photos of the Best Cut Made on 2-in. Steel Plate Using Magnegas 2 and a Tip Designed for Propylene (Trial MG2-22, top corner is shown on left, cut surface is shown on right) ........................................................................................ 26


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1.0 Introduction Magnegas has two products, Magnegas 1 and Magnegas 2, that compete with other fuel gases in the oxyfuel gas cutting products market. Magnegas asked EWI to evaluate their products along with acetylene and propane, with respect to travel speed and gas consumption during oxyfuel gas cutting of steel plate. EWI performed testing with each fuel gas to determine maximum travel speed and the corresponding gas consumption for producing fabrication quality cuts on 1- and 2-in. uncoated steel. The information generated during this project will provide Magnegas with an independent comparison of their products along with competing fuel gases.

2.0 Objectives The objective of this project was to determine gas consumption and travel speed for producing fabrication quality cuts on 1- and 2-in. uncoated steel using Magnegas 1, Magnegas 2, acetylene, and propane.

3.0 Experimental Procedure The equipment used for this project is shown in Figure 1. The steel plate was placed on a cutting table, and the cut was made to a section extending from the side of the cutting table. A Harris Model 98-6E cutting torch was used with acetylene, whereas a Harris Model 98-6F cutting torch was used for propane, Magnegas 1, and Magnegas 2. Each torch was mounted to a track-based Gullco carriage. The fuel gas hose was the Grade T type, so the same hose was used for all fuel gases. A fuel pressure regulator calibrated for Magnegas products by the regulator manufacturer was used for both Magnegas products. A fuel pressure regulator calibrated for acetylene was used for cuts with acetylene, while a fuel pressure regulator calibrated for propane was used for cuts with propane. The same oxygen pressure regular was used for all cuts. The Allicat Model M-100 SLPM-D/SM flow meters shown in Figure 2 were integrated into the fuel and oxygen lines between the torch and the pressure regulators. These flow meters had settings for numerous gases and provided pressure data and flow rate data. The flow meters had settings for acetylene and propane. Magnegas specified to use the fuel gas setting for nitrous oxide for Magnegas 1, and the fuel gas setting for acetylene for Magnegas 2. For Magnegas 1, the flow rates measurements with the nitrous oxide setting are accurate, whereas the actual flow rates for Magnegas 2 are determined by multiplying the flow rates with the acetylene setting by 0.85. The oxygen and fuel gas pressures were set using the digital read-out values on these flow meters.

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Cutting tip size and type were selected for each condition based on cutting equipment manufacturer’s data, the AWS Welding Handbook Volume 2, and input from Magnegas. Regardless of the fuel gas, a size 2 tip was used for 1-in. steel, whereas a size 3 tip was used for 2-in. steel. Torch type and tip type used to make cuts for each condition of fuel gas/plate thickness are listed in Table 1. Harris 6290-2 and 6290-3 tips were used with acetylene and Harris 6290-2NX and 6290-3NX tips were used for propane. Initial trials with Magnegas products were done with Harris 6290-2NXP and 6290-3NXP tips. The deliverable cuts with the Magnegas products were made using American Torch Tip Company (ATTC) NXM-2 and NXM-3 tips. The desired cut quality was determined through input from EWI and Magnegas. Cut quality criteria are listed below:

1. Top and bottom corners are not excessively rounded 2. Cut surface is smooth 3. Cut surface is relatively flat, with minimal waviness or depressions 4. Dross is easily removed with a hammer and a chisel.

For each of the 8 conditions of fuel gas type and plate thickness iterative trials were conducted to determine procedures that produce acceptable cuts at relatively high travel speed using relatively low levels of fuel gas. Faster travel speeds may be achievable with each combination of fuel gas, tip type, and plate thickness, but cut quality may be reduced below the criteria stated above. For all trials the torch travel and work angles were set to 0° and the maximum preheat temperature of the plate prior to starting the cut was limited to 125°F. Parameters screened include the fuel gas flow rate, the preheat oxygen flow rate, the ratio of preheat oxygen flow rate to fuel gas flow rate, travel speed, and torch standoff distance. Tip type was also screened for the Magnegas products. The best procedures for each condition were selected to produce two 36-in. long deliverable cuts during which the preheat time, cutting tip standoff distance, travel speed, fuel gas pressure, oxygen pressure, fuel gas flow rate, preheat oxygen flow rate, and total oxygen flow rate during cutting were measured. For each deliverable cut the dross was removed prior to taking photos of the cut surface. The flow rate, preheat time, and travel speed data were used to calculate fuel gas consumption and oxygen consumption for each deliverable cut. Flatness of the cut surfaces for deliverable cuts made on 2-in. material was quantified using the tools shown in Figure 3. A straight edge was placed on the cut surface near the middle of the cut and a ½-in. wide feeler gage was used to measure the maximum depression of the cut surface. Flatness of the cut surface was not measured for deliverable cuts made on 1-in. plate because these cuts were generally flatter than cuts on the 2-in. plates, and because any depressed areas were too narrow to measure using the feeler gage technique.

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4.0 Results Data for the two deliverable cuts made for each of the 8 fuel gas/plate thickness conditions are presented in this section along with data for the best cuts made using the Magnegas products and the tips designed for propylene. Gas pressures, flow rates, travel speed, and total gas consumption for the deliverable cuts made for each fuel gas/plate thickness condition are listed in Table 2. As noted, the gas consumption calculations do not account for gas consumption during the preheat time. Tips designed for cutting with MAPP gas (ATTC NXM type) were selected to make the deliverable cuts with the Magnegas products. An effort was made to keep the oxygen pressure constant for all conditions. Acceptable procedures were developed for each plate thickness using Magnegas 1, Magnegas 2, and propane with an oxygen pressure of 60 psi. For cuts made with acetylene, oxygen pressures in the range of 45 to 60 psi resulted in unstable conditions, so oxygen pressure of 40 psi was used to produce the deliverable cuts. The Harris Model 98-6E torch used for the acetylene cuts was the positive pressure type meaning that it required conventional fuel gas pressure to operate correctly. Fuel gas pressure settings near the middle of the manufacturer’s recommended range (5 to 15 psi) were used to produce the deliverable cuts made with acetylene. The Harris Model 98-6F torch used for the cuts made with Magnegas 1, Magnegas 2, and propane was the universal pressure type meaning that it could operate with pressures ranging from less than 1 psi up to pressures exceeding 15 psi. The deliverable cuts made with propane used a relatively low pressure setting of 2 psi, whereas the pressure settings for the deliverable cuts made with Magnegas 1 and Magnegas 2 ranged from 5 to 13 psi. For deliverable cuts made on each plate thicknesses, Magnegas 2 provided the highest travel speeds followed by Magnegas 1, acetylene, and then propane. For each plate thickness, oxygen consumption increased approximately with the inverse of travel speed. For deliverable cuts made on 1-in. plate, Magnegas 2 had the lowest oxygen consumption, followed by Magnegas 1, acetylene, and propane. For deliverable cuts made on 2-in. plate, Magnegas 2 had the lowest oxygen consumption followed by Magnegas 1, propane, and then acetylene. For cuts made on both plate thicknesses deliverable cuts made with acetylene had the lowest fuel gas consumption, followed by propane, Magnegas 2, and then Magnegas 1. For each fuel gas, fuel gas flow rates were generally slightly higher for deliverable cuts made on 1-in. plate, then for deliverable cuts made on 2-in. plate. A photo showing the surface of the 1-in. steel plate cut during this project is shown in Figure 4. The 1-in. plate used for all deliverable cuts had similar surfaces consisting of a non-flaking mill scale coating. As shown in Figure 5, the 2-in. plates used to make the deliverable cuts with acetylene had a similar surface appearance. Referring to Figure 6, the surfaces of the 2-in.

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plates used for the deliverable cuts made with Magnegas 1, Magnegas 2, and propane had a slightly different surface coating consisting of mill-scale with areas with flaking. Photos of deliverable cuts made on 1-in. plate with each fuel gas are shown in Figures 7 through 14. All of these cuts had relatively low rounding of the top corner, minimal if any rounding of the bottom corner, and a relatively smooth and flat cut surface. Flatness of these cuts could not be measured using the predefined feeler gage technique, but these cuts were as flat as or flatter than the deliverable cuts made on 2-in. plate. Photos of deliverable cuts made on 2-in. plate with each fuel gas are shown in Figures 15 through 22. All of these cuts had relatively low rounding of the top corner, minimal if any rounding of the bottom corner, and a relatively smooth and flat cut surface. Surface depression measurements for the cut surfaces of deliverable cuts made on 2-in. plate are listed in Table 3. The deliverable cuts made on 2-in. plate with acetylene and propane had a slightly flatter cut surface than those made with the Magnegas products. As a result, areas with surface depressions on the cut surfaces produced with acetylene and propane were too narrow to measure using the ½-in. wide feeler gage. Deliverable cuts made with Magnegas 1 and Magnegas 2 had a maximum surface depression of 0.024 in. Preheat data for each fuel gas/plate thickness combination are listed in Table 4. The preheat time was defined as the duration between when the center of the cut flame arrived at the edge of the plate, and when travel was initiated. For acetylene, Magnegas 1, and propane the operator viewed the edge and initiated travel when the edge became sufficiently molten. As a result the preheat time varied from trial to trial for the deliverable cuts. For Magnegas 2 travel was initiated after an experimentally determined preheat time (i.e., the preheat time for the deliverable cuts was set). Preheat time ranged from 4.9 sec up to 16.1 sec for the deliverable cuts made on 1-in. plate. For this thickness, cuts made with acetylene had the lowest preheat time, whereas cuts made with Magnegas 1 had the highest preheat time. Furthermore, for Magnegas 1 preheating was done with a standoff distance of 1/8 in. and then increased to a main standoff distance of 5/16 in. For deliverable cuts made on 1-in. plate using acetylene, Magnegas 2, and propane the standoff distance used for preheating was the same as that used for cutting. For deliverable cuts made using each fuel gas on 2-in. plate the standoff distance for preheating was the same as that used for cutting. The preheat times ranged from 3.0 to 10.0 sec. Magnegas 2 had the lowest preheat time of 3.0 sec, followed by propane, Magnegas 1, and then acetylene. Comparison of the gas consumption data listed in Table 4 with that listed in Table 2 indicates that the gas consumed during preheat is a very small fraction of the gas consumed during the 36-in.-long cut. Tips designed for propylene were initially used with the Magnegas products. Data for the best cuts made using these tips (Harris 6290-NXP type tips) with the Magnegas products are listed in Table 5. Photos of the best cut made with each of the four fuel gas/thickness conditions are

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shown in Figures 23 through 30. The best cut made on 1-in. plate using either Magnegas product were not fully developed before changing over to the tips designed for MAPP gas. Referring to Figures 23 and 24 the best cut made using the propylene tip and Magnegas 1 on 1-in. plate (MG1-07) had an excessively rounded top corner, but had a smooth and flat cut surface. This condition used a relatively high fuel gas flow rate which likely contributed to the excessive rounding of the top corner. As shown in Figures 25 and 26, the best cut made on the 1-in. plate with Magnegas 2 and the tip designed for propylene had acceptable top and bottom corners, but the cut surface was wavy and did not meet flatness requirements. The best cuts made on 2-in. plate with each Magnegas product and tips designed for propylene met the cut quality criteria. As shown in Figures 27 and 29, both cuts had very little rounding of the top and bottom corners. Referring to Figures 28 and 30 the best cuts made on 2-in. plate with Magnegas 1 and Magnegas 2 and the tips designed for propylene were very flat, and were flatter than the deliverable cuts made on 2-in. plate with tips designed for MAPP gas. Depressed areas on the cut surfaces were too narrow to measure using the feeler gage technique. The fuel gas and preheat oxygen flow rates used for the cuts made on 1-in. plate with the Magnegas products and tips designed for propylene were much higher than the deliverable cuts made on 1-in. plate using the Magnegas products and tips designed for MAPP gas. The travel speeds for the best cuts made on the 1-in. plate with the Magnegas products and tips designed for propylene were comparable to the deliverable cuts made on 1-in. plate with the Magnegas products and tips designed for MAPP gas. Because the travel speeds were comparable and the flow rates were higher, the best cuts made on 1-in. plate using tips designed for propylene had higher gas consumption than the deliverable cuts made on 1-in. plate with tips designed for MAPP gas. The best cut made on 2-in. plate with Magnegas 1 and the tip designed for propylene used a lower fuel gas flow rate and a higher preheat oxygen flow rate than the deliverable cuts made on 2-in. plate using the same fuel gas and tips designed for MAPP gas. The best cut made on 2-in. plate using Magnegas 2 and the tip designed for propylene used higher fuel gas and preheat oxygen flow rates than the deliverable cuts made on 2-in. plate using the same fuel gas and tips designed for MAPP gas. The best cuts made on 2-in. plate using the Magnegas products and tips designed for propylene utilized lower travel speeds than the deliverable cuts made on 2-in. plate using the same fuel gas products and tips designed for MAPP gas. However, the best cuts made on the 2-in. plate with the tips designed for propylene had slightly higher quality due to flatter cut surfaces, compared to the deliverable cuts made on 2-in. plate with tips designed for MAPP gas. To confirm that cutting orifice diameter was relatively constant for a given tip size regardless of the tip type, the cutting gas orifice of one tip of each type was measured using an optical comparator. As listed in Table 6 the diameters ranges for the size 2 and size 3 tips were 0.0019 and 0.0025 in., respectively.

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5.0 Discussion Deliverable cuts made during this project met the criteria listed below:

1. Top and bottom corners are not excessively rounded 2. Cut surface is smooth 3. Cut surface is relatively flat, with minimal waviness or depressions 4. Dross is easily removed with a hammer and a chisel.

For each fuel gas/plate thickness condition iterative trials were conducted to determine procedures that produce acceptable cuts at relatively high travel speeds and relatively low fuel gas flow rates. For deliverable cuts made on each plate thickness, Magnegas 2 provided the highest travel speeds followed by Magnegas 1, acetylene, and then propane. Listed in Table 7 is a comparison of the flow rate and travel speed values listed in the AWS Handbook Volume 2 for cuts made with acetylene and propane with the values for deliverable cuts made during this project.(Ref. 1) The deliverable cuts made with acetylene and propane had travel speed near the top end of the range listed for the corresponding condition in the AWS Handbook. For both plate thicknesses deliverable cuts made with acetylene had the lowest fuel gas consumption, followed by propane, Magnegas 2, and then Magnegas 1. Referring to Table 7, the fuel gas flow rates for deliverable cuts made on 1-in. plate with acetylene and propane were near the low end of the range specified in the AWS Handbook. Deliverable cuts made with acetylene and propane on 2-in. plate were made with fuel gas flow rates just below the range listed in the AWS Handbook for cuts made on 2-in. plate with each gas. The ability to cut with relatively low flow rates is at least partially due to the mechanized setup. The total oxygen flow rate during cutting is defined as the oxygen flow rate when the cutting oxygen valve is opened. The tip size being used along with the preheat oxygen flow rate have the greatest effect on the total oxygen flow rate, but other factors such as the oxygen pressure setting, torch design, and tip design may also influence this value to a much lesser degree. Referring to Table 2, because tip size was held constant for a given plate thickness, and the preheat oxygen flow rates were within a range of 3-LPM, the total oxygen flow rate during cutting was within a relatively tight range for cuts made on each plate thickness. For a given plate thickness oxygen consumption tended to increase as the travel speed was reduced. As a result, cuts made with the highest travel speed (Magnegas 2) had the lowest oxygen consumption while cuts made with the lowest travel speed (acetylene or propane) had the highest oxygen consumption.

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The preheat time is dependent on several factors including the fuel gas characteristics, fuel gas to preheat oxygen ratio, fuel gas flow rate, preheat oxygen flow rate, position of flame on the edge (i.e., half the flame is over the edge verses a quarter of the flame, etc.), and standoff distance during preheating. For deliverable cuts made on 1-in. plate the preheat times for acetylene and propane were lower than the preheat times for Magnegas 1 and Magnegas 2. For Magnegas 1 the standoff distance during preheating was reduced (compared to the main cut) as a means of lowering the preheat time. Constant standoff distances were used for the deliverable cuts made on 2-in. plate. For the 2-in. plate Magnegas 2 had the lowest preheat time, followed by propane, Magnegas 1, and acetylene. The fuel gas flow rate used with acetylene and 2-in. plate was set at a low value to avoid excessive melting of the top corner. Increasing the acetylene gas flow rate while keeping the ratio of fuel gas to preheat oxygen flow rate constant, or reducing the standoff distance at the start of the cut would reduce the preheat time required for the 2-in. plate. This data indicates that when fuel gas flow rates are used that produce lower preheat capability, preheat time can be reduced by using shorter standoff distance at the start, and then increasing the standoff to the steady-state value once the cut is initiated. Regardless of the fuel gas used, gas consumption during preheating is a very small fraction of the total gas consumption used during production of the 36-in. cut. Tip design can affect travel speeds attainable for a given fuel gas and plate thickness combination, as well as the corresponding fuel and oxygen consumption rates. The travel speed and gas consumption data for the deliverable cuts made with each fuel gas was determined using the specified tip type. Faster travel speeds maybe attainable for a given fuel gas with different tip designs. Faster travel speeds may also be attainable using the pressure and flow rate settings defined for the deliverable cuts if a reduction in cut quality is acceptable. The data for the best cuts made using the Magnegas products and tips designed for propylene was included in this report to demonstrate how tip design and gas flow rates can affect cutting characteristics. The best conditions developed on 1-in. plate using the tips designed for propylene produced lower quality cuts than the deliverable cuts on 1-in. plate using the same fuel gases and tips designed for MAPP gas. The reduced cut quality is likely due to the conditions being underdeveloped for cuts made on 1-in. plate with the Magnegas products and tips designed for propylene. Because the cuts made on 1-in. plate with the propylene tips were underdeveloped, the attainable travels speeds for cuts made using these tips cannot be compared with those of the deliverable cuts made using MAPP tips. Both the best cuts made on 2-in. plate using the Magnegas products and tips designed for propylene, and the deliverable cuts made with the Magnegas products and the tips designed for MAPP gas had acceptable quality. The deliverable cuts made on 2-in. plate with tips designed for MAPP gas were made at higher travel speed than the best cuts made on 2-in. plate with tips designed for propylene, but the cut surfaces of the best cuts made with the propylene tips were flatter than the surfaces of the deliverable cuts made using the tips designed for MAPP gas.

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6.0 Conclusions Tip design can affect travel speeds attainable for a given fuel gas and plate thickness combination, and the corresponding fuel gas and oxygen consumption rates. The travel speed and gas consumption data for the deliverable cuts made with each fuel gas was generated using the specified tip type. Faster travel speeds maybe attainable for a given fuel gas with different tip designs. Faster travel speeds may also be attainable using the pressure and flow rate settings defined for the deliverable cuts if a reduction in cut quality is acceptable. Deliverable cuts made during this project met the previously defined criteria. Acetylene, Magnegas 1, Magnegas 2, and propane were evaluated regarding cutting travel speed and gas consumption by producing cuts on 1- and 2-in. plate. For each fuel gas/plate thickness condition iterative trials were conducted to determine procedures that produce acceptable cuts at relatively high travel speeds and relatively low fuel gas flow rates. The conclusions from this project are listed below:

1. All deliverable cuts were met the predefined criteria. 2. For deliverable cuts made on each plate thickness, Magnegas 2 had the highest travel

speeds followed by Magnegas 1, acetylene, and then propane. 3. For each plate thickness Magnegas 1 had the highest fuel gas consumption followed by

Magnegas 2, propane, and then acetylene. 4. Oxygen consumption to make a 36-in. cut was primarily dependent on the cutting tip size

and the travel speed of the cut. For a given plate thickness (and tip size) oxygen consumption to make a 36-in. cut tended to reduce as the travel speed increased. Magnegas 2 had the lowest oxygen consumption, followed by Magnegas 1, acetylene, and then propane for deliverable cuts made on 1-in. plate. Magnegas 2 had the lowest oxygen consumption, followed by Magnegas 1, propane, and then acetylene for deliverable cuts made on 2-in. plate.

5. Preheat time only accounts for a small fraction of the gas consumption required to produce a 36-in. long cut on each plate thickness using each fuel gas. Preheat time varied for deliverable cuts made on each plate thickness. These variations are at least partially attributable to gas characteristics, flow rates, and position of the torch during preheating.

6. Flatness was measured for deliverable cuts made on 2-in. plate, and the best cuts made on 2-in. plate using Magnegas products and the tips designed for propylene. All of these cuts met the defined criteria. The cut surfaces of the deliverable cuts made with the Magnegas were less flat than the deliverable cuts made with acetylene and propane, as well as the best cuts made using Magnegas products and the tips designed for propylene.

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7.0 Future Work The fuel gases evaluated during this project have different chemistries, flame characteristics, and combustion reactions during cutting. The surface of cuts made using conventional fuel gases such as acetylene and propane can be hardened during cutting. This hardening is dependent on the base metal chemistry as well as diffusion of carbon or other by-products of the combustion reactions into the cut surface. Many fabrication operations do not require the cut surface to be ground prior to welding. However certain applications require grinding of the cut surface prior to welding to remove the hardened surface, or as a means of eliminating any deleterious by-products that may be present in the cut surface. Grinding of the flame cut surfaces is often required in shipbuilding or pipeline applications where high strength steels are used. If Magnegas plans to market its products to industries that require grinding of the flame cut surface prior to welding, then it is recommended that cuts produced with the Magnegas products be evaluated to determine the following: (1) is the cut surface hardened, (2) what is the depth of hardening at the cut surface, and (3) what is the chemistry of the cut surface (i.e., does the cut surface contain extra carbon or any deleterious tramp elements from the reactions with the fuel gas). Knowing these characteristics will help Magnegas to better market its products to certain industries.

8.0 Reference 1. AWS Handbook Volume 2, Eighth Edition.

9.0 Disclaimer EWI disclaims all warranties, express or implied, including, without limitation, any implied warranty of merchantability or fitness for a particular purpose. Under no circumstances will EWI be liable for incidental or consequential damages, or for any other loss, damage, or expense, arising out of or in connection with the use of or inability to use the report delivered under this engagement. This report may not be reproduced or disseminated to individuals or entities outside of your organization without the prior written approval of EWI.

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Table 1. Torch Type and Tip Type Used to Make the Deliverable Cuts for Each Fuel Gas/Plate Thickness Condition

Fuel Gas Thickness

(in.) Torch Type Tip Type(s)

Acetylene 1 Harris Model 98-6E Harris 6290-2 Magnegas 1 1 Harris Model 98-6F Harris 6290-2NXP, ATTC NXM-2(a) Magnegas 2 1 Harris Model 98-6F Harris 6290-2NXP, ATTC NXM-2(a)

Propane 1 Harris Model 98-6F Harris 6290-2NX Acetylene 2 Harris Model 98-6E Harris 6290-3

Magnegas 1 2 Harris Model 98-6F Harris 6290-3NXP, ATTC NXM-3(a) Magnegas 2 2 Harris Model 98-6F Harris 6290-3NXP, ATTC NXM-3(a)

Propane 2 Harris Model 98-6F Harris 6290-3NX (a) ATTC NXM-2 and ATTC NXM-3 cutting tips were used for deliverable cuts made with

Magnegas products

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Table 2. Gas Pressures, Flow Rates, Travel Speed, and Total Gas Consumption for the Deliverable Cuts Made for Each Fuel Gas/Plate Thickness Condition (Gas Consumption Does Not Account for the Preheat Time)

ID Fuel Gas Thickness

(in.)

Pressures (psi)

Flow Rates (LPM) Travel

Speed (ipm)

Main Standoff Distance

(in.)

Gas(a)(b) Consumption (Litters)

Fuel Oxygen Fuel Preheat Oxygen

Total Oxygen

Fuel Oxygen

ACE-12 Acetylene 1

10.0 40.0 4.0 4.8 24.5 17.4 1/8- to 3/16 8.3 50.7 ACE-13 10.0 40.0 4.0 4.8 24.7 17.4 1/8- to 3/16 8.3 51.1

MG1-06S-A Magnegas 1 1

13.0 60.2 12.1 2.3 20.7 18.0 5/16 24.2 41.4 MG1-06S-C 12.3 56.1 12.1 2.3 20.4 18.0 5/16 24.2 40.8 MG2-09S-A

Magnegas 2 1 5.0 61.0 8.3 1.9 20.1 21.0 3/8 14.2 34.5

MG2-09S-B 5.0 61.0 8.3 1.9 20.0 21.0 1/4 14.2 34.3 PRP-010-B

Propane 1 2.0 60.0 4.5 5.0 23.5 15.0 3/16 10.8 56.4

PRP-010-C 2.0 60.0 4.5 5.0 23.5 15.0 3/16 10.8 56.4 ACE-30-A

Acetylene 2 10.0 40.0 3.0 3.5 30.5 13.0 1/4 8.3 84.5

ACE-30-C 10.0 40.0 3.0 3.5 31.0 13.0 1/4 8.3 85.8 MG1-08S-A

Magnegas 1 2 9.9 60.6 12.5 2.6 29.2 16.0 3/16 28.1 65.7

MG1-08S-B 10.0 60.0 12.5 2.6 29.3 16.0 3/16 28.1 65.9 MG2-13S-A

Magnegas 2 2 9.8 60.0 7.2 2.0 28.4 18.0 1/4 14.4 56.8

MG2-13S-B 10.3 60.4 7.2 2.0 28.6 18.0 1/4 14.4 57.2 PRP-05-A

Propane 2 2.0 60.0 3.3 3.2 28.4 12.5 1/8 9.5 81.8

PRP-05-B 2.0 60.0 3.3 3.2 28.1 12.5 1/8 9.5 80.9 (a) Gas consumption required to make a 36-in.-long cut. (b) Gas consumption does not account for the gas consumed during the preheat time.

12

Table 3. Surface Depression Measurements for the Cut Surfaces of Deliverable Cuts Made on 2-in. Plate

ID Fuel Gas Maximum Depth

(in.) ACE-30-A Acetylene Note A ACE-30-C Note A

MG1-08S-A Magnegas 1 0.024 MG1-08S-B 0.019 MG2-13S-A Magnegas 2 0.021 MGS-13S-B 0.015 PRP-05-A Propane Note A PRP-05-B Note A

(a) Any depressed areas on the cut surface are too narrow to measure with the feeler gage

13

Table 4. Preheat Data for Deliverable Cuts Made for Each Fuel Gas/Plate Thickness Combination


(in.)


(in.)

Preheat Standoff Distance

(in.)

Preheat Time (sec)

Fuel Gas Flow Rate

(LPM)

Preheat Oxygen

Flow Rate

(LPM)

Gas Consumption

During Preheat (Liters)

Fuel Oxygen ACE-12

Acetylene 1 1/8 to 3/16 1/8 to 3/16 5.1 4.0 4.8 0.34 0.41

ACE-13 1/8 to 3/16 1/8 to 3/16 4.9 4.0 4.8 0.33 0.39 MG1-06S-A

Magnegas 1 1 5/16 1/8 7.1 12.1 2.3 1.43 0.27

MG1-06S-C 5/16 1/8 16.1 12.1 2.3 3.25 0.62 MG2-09S-A

Magnegas 2 1 3/8 3/8 7(a) 8.3 1.9 0.97 0.22

MG2-09S-B 1/4 1/4 9(a) 8.3 1.9 1.25 0.29 PRP-010-B

Propane 1 3/16 3/16 5.6 4.5 5.0 0.42 0.47

PRP-010-C 3/16 3/16 6.9 4.5 5.0 0.52 0.58 ACE-30-A

Acetylene 2 1/4 1/4 7.0 3.0 3.5 0.35 0.41

ACE-30-C 1/4 1/4 10.0 3.0 3.5 0.50 0.58 MG1-08S-A

Magnegas 1 2 3/16 3/16 4.8 12.5 2.6 1.00 0.21

MG1-08S-B 3/16 3/16 4.8 12.5 2.6 1.00 0.21 MG2-13S-A

Magnegas 2 2 1/4 1/4 3.0(a) 7.2 2.0 0.36 0.10

MGS-13S-B 1/4 1/4 3.0(a) 7.2 2.0 0.36 0.10 PRP-05-A

Propane 2 1/8 1/8 4.3 3.3 3.2 0.24 0.23

PRP-05-B 1/8 1/8 4.1 3.3 3.2 0.23 0.22 (a) For Magnegas 2 travel was started after a predefined preheat time.

14

Table 5. Gas Pressures, Flow Rates, Travel Speed, and Total Gas Consumption for the Best Cuts Made Using Magnegas Products and Cutting Tips Designed for Propylene Gas (Harris 6290-NXP Type Tips)


(in.)

Pressures (psi)

Flow Rates (LPM) Travel

Speed (ipm)


(in)

Gas(a)(b) Consumption (Litters)

Fuel Oxygen Fuel Preheat Oxygen

Total Oxygen

Fuel Oxygen

MG1-07 Magnegas 1 1 12.7 47.6 21.9 7.8 26.1 20.5 1/8 38.5 45.8 MG2-16 Magnegas 2 1 5.1 60.5 18.6 4.9 23.2 22.0 3/8 30.4 38.0 MG1-11 Magnegas 1 2 11.6 58.7 9.0 3.2 28.6 14.0 1/4 23.1 73.5 MG2-22 Magnegas 2 2 8.9 60.0 8.2 2.4 28.0 14.0 1/4 21.1 72.0

(a) Gas consumption required to make a 36-in.-long cut. (b) Gas consumption does not account for the gas consumed during the preheat time. Table 6. Cutting Orifice Diameters for One Tip for Each Combination of Tip Type and Size

Tip Size Tip Type Tip

Manufacturer’s Specified Gas

Cutting Orifice Diameter

(in.) 2 Harris 6290-2 Acetylene 0.06455 2 Harris 6290-2NXP Propylene 0.06440 2 Harris 6290-2NX Propane 0.06560 2 ATTC NXM-2 MAPP 0.06370 3 Harris 6290-3 Acetylene 0.0769 3 Harris 6290-3NXP Propylene 0.0787 3 Harris 6290-3NX Propane 0.0794 3 ATTC NXM-3 MAPP 0.07725

15

Table 7. Comparison of the Flow Rate and Travel Speed Values Listed in the AWS Handbook Volume 2 for Cuts Made With Acetylene and Propane With the Values for Deliverable Cuts Made During this Project

Thickness (in.)

AWS Handbook Values(Ref. 1) Values for Deliverable Cuts Travel Speed (ipm)

Acetylene Flow Rate

(LPM)

Propane Flow Rate

(LPM)

Acetylene Travel Speed

(ipm)

Propane Travel Speed

(ipm)

Acetylene Flow Rate

(LPM)

Propane Flow Rate

(LPM) 1 9-18 3-5 3-8 17.4 15.0 4.0 4.5 2 6-13 4-8 4-10 13.0 12.5 3.0 3.3

16

Figure 1. Cutting Equipment, Positioning System, and Cutting Table

Figure 2. Allicat Model M-100 SLPM-D/SM Flow Meters

17

Figure 3. Photo Showing the Feeler Gage and Straight Edge Used to Measure Maximum Depth of Surface Depression for Deliverable Cuts Made on 2-in. Steel Plates

Figure 4. Photo Showing the Surface of the 1-in. Steel Plates Cut During this Project

18

Figure 5. Photo Showing the Surface of the 2-in. Steel Plates Cut During This Project

Using Acetylene

Figure 6. Photo Showing the Surface of the 2-in. Steel Plates Cut During this Project

Using Magnegas 1, Magnegas 2, and Propane

19

Figure 7. Photos of a Deliverable Cut Made Using Acetylene on a 1-in. Steel Plate

(Trial ACE 12, top corner is shown on the left, cut surface is shown on the right)

Figure 8. Photo of Deliverable Cut Made Using Acetylene on a 1-in. Steel Plate

(Trial ACE 12, straight edge placed on cut surface to show flatness)

Figure 9. Photos of a Deliverable Cut Made Using Magnegas 1 on a 1-in. Steel Plate

(Trial MG1-06S-A, top corner is shown on the left, cut surface is shown on the right)

Top Surface

Travel

Top Surface Top Surface

Travel

20

Figure 10. Photo of Deliverable Cut Made Using Magnegas 1 on a 1-in. Steel Plate

(Trial MG1-06S-A, straight edge placed on cut surface to show flatness)





Top Surface

Top Surface

Travel

Top Surface

21

Figure 13. Photos of a Deliverable Cut Made Using Propane on a 1-in. Steel Plate

(Trial PRP-10-A, top corner is shown on the left, cut surface is shown on the right)

Figure 14. Photos of a Deliverable Cut Made Using Propane on a 1-in. Steel Plate

(Trial PRP-10-A, straight edge placed on cut surface to show flatness)


(Trial ACE-12, top corner is shown on the left, cut surface is shown on the right)

Top Surface

Top Surface

Travel

Top Surface

Travel

22


(Trial ACE-12, straight edge placed on cut surface to show flatness)



Figure 18. Photo of a Deliverable Cut Made Using Magnegas 1 on a 2-in. Steel Plate


Top Surface

Travel

Top Surface

Top Surface

23



Figure 20. Photo of a Deliverable cut made using Magnegas 2 on a 2-in. Steel Plate


Figure 21. Photos of a Deliverable Cut Made Using Propane on a 2-in. Steel Plate (Trial

PRP-05A, top corner is shown on the left, cut surface is shown on the right)

Top Surface

Travel

Top Surface

Top Surface

Travel

24

Figure 22. Photo of a Deliverable Cut Made Using Propane on a 2-in. Steel Plate (Trial

PRP-05A, straight edge placed on cut surface to show flatness)

Figure 23. Photos of the Best Cut Made on 1-in. Steel Plate Using Magnegas 1 and a

Tip Designed for Propylene (Trial MG1-07, top corner is shown on left, cut surface is shown on right)

Figure 24. Photo of the Best Cut Made on 1-in. Steel Plate Using Magnegas 1 and a Tip

Designed for Propylene (Trial MG1-07, straight edge placed on cut surface to show flatness)

Top Surface

Top Surface

Top Surface

25







Top Surface

Top Surface

Top Surface

26







Top Surface

Top Surface

Top Surface

Documents

Evaluation of Oxyfuel Gas Cutting Gases