1. A method of continuously casting molten steel into a beam blank comprising a first flange portion, a second flange portion and a neck portion interconnecting the first and second flange portions, the method comprising:
providing a mold for the beam blank, the mold comprising a first flange-forming region, a second flange-forming region and a neck-forming region located between the first flange-forming region and the second flange-forming region;
introducing a first molten steel composition into the mold via a nozzle outlet disposed in the first flange-forming region of the mold and immersed in the first molten steel composition cast in the first flange-forming region of the mold;
placing a connecting rod within the second flange-forming region such that a substantial portion of the connecting rod is immersed in the first molten steel composition cast in the second flange-forming region of the mold;
introducing a second molten steel composition into the first flange-forming region of the mold so that the second molten steel composition is cast over the first molten steel composition cast in the mold and that the connecting rod is immersed in the second molten steel composition cast in the mold; and
cooling the first and second molten steel compositions to form the beam blank, which comprises the connecting rod in the second flange thereof.
2. The method of claim 1, wherein the outlet of the nozzle is open downward.
3. The method of claim 1, further comprising, prior to placing the connecting rod, removing mold powder.
4. The method of claim 1, wherein casting is performed without drawing a cast piece while the first molten steel composition stays in the mold prior to the introduction of the second molten steel composition.
5. The method of claim 4, wherein the rate of introducing the second molten steel composition into the mold ranges from 0.55 mmin to 0.7 mmin.
6. The method of claim 1, wherein the level of the first molten steel composition staying in the mold is maintained from 25% to 35% prior to the introduction of the second molten steel composition.
7. The method of claim 1, further comprising supplying mold powder to the mold, wherein the mold powder comprises CaO in an amount of 32.7\u02dc33.7 wt %, SiO2 in an amount of 29.3\u02dc30.3 wt %, Al2O3 in an amount of 8.90\u02dc9.90 wt %, Na2O in an amount of 1.8\u02dc2.8 wt %, F in an amount of 1.10\u02dc2.10 wt % and C in an amount of 15.6\u02dc16.6 wt %.
8. The method of claim 1, further comprising, prior to introducing the second molten steel composition, removing mold powder staying in the mold.
9. The method of claim 1, wherein the first molten steel composition is introduced from a first tundish, and the second molten steel composition is introduced from a second tundish, wherein the method further comprises replacing the first tunish with the second tundish comprising, prior to introducing the second molten steel, replacing tundishes.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A lubrication system for a natural gas compressor, in which a lubricant is periodically injected into the compressor cylinder through a check valve that prevents natural gas from entering the lubrication system, comprising:
a device positioned between the compressor cylinder and the check valve to maintain an oil seal to prevent natural gas from fouling the check valve, the device having a fill capacity that requires less than 10 cycles of a lubricant pressurization device to fill the fill capacity, the device further comprising two bores cut into a solid plug having a threaded end for attaching to the compressor cylinder, one bore leading to the compressor cylinder and the other bore leading to a threaded opening for attaching the check valve; and
wherein the lubricant pressurization device is in fluid communication with the device and supplies no more than 0.098 cm3 (0.006 cubic inches) of lubricant to the device each cycle.
2. The device of claim 1 in which the device includes a path for lubricant, the direction of the path changing within the device to trap oil between the check valve and the compressor within the path for lubricant.
3. The device of claim 1 in which the fill capacity requires less than 2 cycles of the lubricant pressurization device to fill the fill capacity.
4. The device of claim 1 in which the device has a fill capacity that requires less than 7 cycles of the lubricant pressurization device to fill the fill capacity.
5. The device of claim 1 in which the device has a fill capacity that requires less than 5 cycles of the lubricant pressurization device to fill the fill capacity.
6. The device of claim 1 in which the device has a fill capacity that requires less than 3 cycles of the lubricant pressurization device to fill the fill capacity.
7. An assembly for introducing lubricant into a natural gas compressor, comprising:
the device in accordance with claim 1; and
the check valve connected to an inlet bore of the device.
8. The assembly of claim 7 further comprising a divider block for distributing oil to the check valve.