Chapter 188: Bessemer Process Part 2
Ernest checked his pocket watch, noting the exact minute in his logbook.
Around the vessel, the floor was cleared. The blast engine operator stood at his control panel, watching the pressure gauges. The emergency water cooling systems hummed in the background.
Hollen glanced at Ernest. "Your kettle is charged."
"Raise the vessel," Ernest ordered the operator.
The operator engaged the hydraulic tilting gear. The heavy machinery groaned, and the massive vessel began rotating back toward the vertical position. Forty degrees... sixty... eighty... until the converter locked squarely beneath the exhaust hood.
"Vessel locked in blowing position!"
The shop fell entirely quiet. The only sound was the deep, rhythmic beat of the steam blowing engine in the adjacent building—the mechanical lungs of the steelworks.
Hollen stepped up beside Ernest. "Last chance to abort."
Ernest looked up at the machine he had engineered. For centuries, ironmasters had produced small, expensive batches of steel through laborious puddling methods. Today, he was attempting to produce fifteen tons of refined steel in a single twenty-minute operation.
If it succeeded, it would supply the rails for a kingdom.
Ernest raised his hand. "Engage the blast."
The operator pulled the primary air valve.
For a fraction of a second, nothing happened. Then the heavy steel air lines shuddered as high-pressure air slammed through the hollow trunnion, into the lower windbox, through the nineteen bottom tuyeres, and directly into the bath of liquid metal.
ROOOOOOOOOOOAR!
The converter erupted.
A violent, deafening roar tore through the building. Every man on the floor instinctively took a step back. A fountain of incandescent sparks and dense, orange-brown smoke shot from the mouth of the vessel directly into the overhead extraction hood.
Up in the gallery, Arthur gripped the iron railing, his eyes wide. "What in the world..."
Hollen leaned over the barrier, shouting over the din. "Ernest!"
"I see it!" Ernest shouted back, his eyes fixed on the vessel.
Inside the converter, oxygen was reacting violently with the impurities in the iron. Silicon and manganese oxidized first, releasing intense thermal energy that raised the bath temperature rapidly. Thousands of high-pressure air bubbles churned through the liquid metal, turning the bath into a boiling cauldron.
"Blast pressure?" Ernest called out.
The instrument technician checked the water column gauge. "Pressure stable at twenty-two pounds per square inch!"
"Airflow?"
"Holding steady!"
"Trunnion bearing temperatures?"
"Normal!"
Ernest logged the readings rapidly. One minute... two minutes.
The flame emerging from the mouth began to transform. The dense brown smoke cleared, replaced by a longer, brighter yellow flame that extended several meters into the collector hood.
Hollen watched the roaring plume. "It’s intensifying!"
"That’s the silicon finish!" Ernest called back. "The carbon reaction is starting!"
Right on cue, the character of the blow shifted. A brilliant, blinding white tongue of flame burst from the vessel’s mouth with a deep, pressurized WHOOSH. Incandescent particles sprayed against the iron hood, bathing the entire converter hall in stark, white-hot light.
The gallery erupted in startled shouts from the managers, but Ernest felt a surge of pure, quiet exhilaration.
The dissolved carbon was oxidizing, forming carbon monoxide gas that burned brilliantly as it met atmospheric oxygen at the mouth. The reaction was self-sustaining; the burning impurities were supplying the heat required to keep the refined metal liquid.
"You’re smiling!" Hollen yelled over the deafening roar.
"It’s working!" Ernest shouted back. "The thermodynamics are holding!"
"We don’t know if the metal is good yet!"
"We know the bath hasn’t frozen, and the tuyeres haven’t clogged!" Ernest laughed.
The flame continued its blinding roar for five... six... seven minutes. Ernest never took his eyes off the plume. This was the critical phase. They had no electronic sensors, no optical pyrometers, and no automated carbon analyzers. They were relying entirely on visual observation, timing, and physical chemistry.
At eight minutes and forty seconds, Ernest noticed a subtle shift.
The brilliant white plume began to waver. Its length shortened, and its blinding intensity began to drop.
Ernest leaned forward over the barrier, his heart pounding. "Watch the flame!"
"What is happening?" Hollen asked.
"The carbon is nearly exhausted," Ernest said, watching the plume carefully.
If he stopped the blast too early, too much carbon would remain, leaving the metal as high-carbon steel or pig iron. If he let the blast run too long, the oxygen would begin burning the iron itself, destroying the yield and ruining the batch with heavy iron oxides.
Nine minutes... nine minutes fifteen seconds... nine minutes thirty seconds.
The brilliant white flame suddenly dropped away, collapsing into a short, pale-blue feathery flame.
Ernest raised his hand instantly. "STOP THE BLAST! TILT THE VESSEL!"
The operator slammed the main air control valve shut and engaged the tilting drive.
CLANG!
The high-pressure blast cut off, and the deafening roar died instantly. The sudden silence in the massive hall was almost jarring.
The heavy trunnions rotated, bringing the converter mouth forward into the pouring position. A thick layer of liquid slag floated over a glowing, liquid bath.
Smoke drifted slowly toward the roof trusses. No one spoke. The operators stood frozen at their stations.
Fifteen tons of refined metal rested inside Pneumatic Converter No. 1.
Ernest closed his logbook, his hands steady. He looked at the chief ladle operator.
"Take a sample ingot for the laboratory," Ernest ordered calmly. "And prepare the casting ladle."
The converter tipped further, and a smooth, brilliant stream of liquid steel poured into the sampling ladle, throwing fine, delicate sparks into the air.
The young laboratory metallurgist rushed forward with long iron tongs, catching a small quantity of the glowing stream into a heavy cast-iron mold. He immediately quenched the small sample in a water tub, generating a violent plume of steam before hurrying off toward the chemical laboratory to run the fracture and carbon tests.
Hollen stepped up beside Ernest, watching the remaining molten metal settle inside the main transfer ladle. The radiant heat radiated against their faces in waves.
"If the carbon numbers come back right," Hollen whispered, "you’ve just rewritten forty years of metallurgy in nine minutes."
Ernest smiled faintly, staring down at the glowing pool. "We didn’t rewrite it, Hollen. We just gave it a faster engine."
The first pneumatic blow in the history of Belfast was complete. Now, they would find out if they had made steel.