SGI steel degassing mechanical vacuum pump- set module lines are based on:
For VD process 3, 4 and 5- stage vacuum degassing line systems. For VOD/RH process 2 to 3 stages
Prefabricated VD/VOD/RH machine stage
VD Vacuum steel degassing module lines:
Three stage VD vacuum module line system
The SGI machine installation in a three stage steel degassing line consisting of a (HV) high vacuum rotary piston blower as first stage to the evacuation side and in the second stage a pre-inlet cooled rotary piston blower from Aerzener Maschinenfabrik. The third stage is a special dry screw vacuum pump.
Four stage VD vacuum module line system
The SGI machine installation in a four stage degassing line system consisting of a (HV) high vacuum rotary piston blower as first and second stage to the evacuation side and in the third stage a pre- inlet cooled rotary piston blower from Aerzener Maschinenfabrik. The fourth stage is a special dry screw vacuum pump.
Five stage VD vacuum module line system for very large systems or very low energy consumptions.
VOD/RH Vacuum steel degassing module lines:
Two stage VOD/RH vacuum module line system, in accordance to ATEX.
The SGI machine installation in a two stage module line consisting of a pre-inlet cooled rotary piston blower stage combined with a special dry screw vacuum pump. This two stage VOD/RH module line can be a part from a 3,4,or 5 stage VD module line.
Three stage VOD/RH vacuum module line system,in accordance to ATEX.
The SGI machine installation in a three stage module line consisting of a 1. and 2. pre-inlet cooled rotary piston blower stage combined with a special dry screw vacuum pump as last stage. This three stage VOD/RH module line can be a part from a 4, or 5 stage VD module line.
Sizing a steel degassing line with mechanical pumps
The following sizing parameters are based on tonnes of liquid metal.
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VD vacuum suction capacity at 0,7 mbara 1.300 -1.500 m3/h/ton at 50 - 80°C
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VOD/ suction capacity at 130 mbara/ 200-250 m3/h/ton and at 30°C or 25-45 kg/h/ton
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RH Control and pump down flow 200-250 m3/h/ton
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VD System air leakage expected 0,15-0,25 kg/h/ton
Temperature influence
Higher gas temperature in the VOD process will influence thermal load of machine stages as well as mass flow. In order to protect machines therefore pre cooling is required.
Higher VD machine suction temperature over design 50 to 80°C will reduce suction flow of volumetric HV machine stages.
Due to low gas flow density (kg/m3) at stationary VD process at 0,7 mbara, higher gas temperature in VD process will not influence thermal load of machine stages but will influence final suction pressure due to existing latent gas heat in the middle of the VD suction gas pipe.
SGI Vacuum module steel degassing line systems A1, A2, A2x and B, B1 for VD/VOD/RH process
| Module | for VD at 0,7 mbara, | VD Energy | for VOD at 130 mbara, | VOD Energy |
| A1 | 39.000 m3/h, three stages | 60 kW | 7.100 m3/h two stages | 134 kW |
| A2/a | 42.000 m3/h, four stages | 48 kW | 3.400 m3/h two stages | 68 kW |
| A2/b | 42.000 m3/h, four stages | 50 kW | 6.200 m3/h two stages | 182 kW |
| A2x | 80.000 m3/h, four stages | 76 kW | 7.100 m3/h two stages | 134 kW |
| B | 94.000 m3/h, four stages | 102 kW | 12.000 m3/h two stages | 220 kW |
| Bx 1/2 | 177.000 m3/h, four stages | 129 kW | 12.000 m3/h two stages | 220 kW |
| B1 | 94.000 m3/h, five stages | 74 kW | 12.000 m3/h three stages | 244 kW |
| B1 x 1/2 | 177.000 m3/h, five stages | 104 kW | 12.000 m3/h three stages | 244 kW |
Customer can duplicate or even triplicate the steel degassing modules A1, A2, A2x and B, Bx, B1x or can combine modules depending on requirements for size of VD or VOD/RH process.
The machinery for A1, A2, A2x modules can be completely installed on skid or in an machine container.
For Modules B, Bx and B1, B1x four stages of five can be installed in on a common skid or in an machine container. Due to the size the first stage will be installed on machine frame outside basic skid or container.
Typical process flow of a SGI steel degassing vacuum pump set module line
The flow diagram Fig.1 is drawn for a three stage vacuum module steel degassing line system, four stages have only one (HV) stage in serial installation more. The instrumentation for controlling the system is not shown in the process flow diagram).
The SGI installation in a three stage degassing line consists a water cooled pre- cyclone and a pre-cooler optional for VOD process, a water cooled bag-filter and as first vacuum machine stage to the evacuation side a (HV) high vacuum rotary piston blower with intercooler and in the second stage a pre-inlet cooled rotary piston blower with intercooler, the third stage are two dry screw vacuum pumps.
Figure 1
Container installation
Beside installation of SGI steel degassing line inside a building it is possible to install the steel degassing module lines A/A1and A2 inside a noise protected machine container Figure 2.
Advantage of machine container installation
No need for a special machine foundation only a concrete base plate is required for the machine container
No need for a noise protected and ventilated machine house or no need for complicated high costly modification of an existing building
The mechanical vacuum steel degassing line is completely installed and piped in the machine container
The machines are installed inside the container on flexible machine elements so that no dynamic machine forces are transferred to the concrete base plate
Wiring of machines and instrumentation to a terminal box inside the machine container
Noise protection of the machine container wall down to 80 dB(A) pressure sound level in 1 m distance from outside container wall as well as from off-gas noise silencer
Ventilation of machines inside the container to transfer the radiated machine heat via the ventilation air outside the container
The container ventilation system includes inlet and outlet noise elimination houses
No packing of the degassing line is required for shipping
No mounting of single degassing line machines and components at site is required
Short installation time of steel degassing line because machinery inside container is completely mounted, piped, instrumented, wired and tested.
Machine container installation of steel degassing module line A1
Figure 2
Pictures of containerized vacuum pump-set solutions steel degassing lines A1 - A2
Pictures inside machine house: Vacuum pump-set solutions steel degassing line A1
Pictures inside machine house: Vacuum pump-set solutions steel degassing line 2 x A2
Customized large vacuum pump-set B/B1 solutions for Saldanha Steel in South Africa
Picture 1 » Largest vacuum machine stage for steel degassing 92.000 m3/h
Picture 2-3 » Pre-inlet cooled machines in the size up to 55.000 m3/h
Picture 4 » Largest inter-stage Cooler for steel degassing 92.000 m3/h
