SCHMIDT’SCHE® PROCESS GAS BOILER
Process gas boilers are the SCHMIDT'SCHE® solutions for steam reforming plants.
Depending on the process requirements, the gas downstream of the process gas cooler is used to superheat steam, preheat boiler feed water/feed or to enter it into the CO-shift converter.
SCHMIDT'SCHE® PROCESS GAS BOILER
SCHMIDT'SCHE® Process Gas Boilers are designed to withstand even extreme operation conditions and therefore ensure safe operation of steam reforming plants. Our engineers develop highly sophisticated designs which make the process gas boiler resistant to high temperatures and corrosion.
They are installed at the end of steam reforming processes. The process gas exiting the reformer catalyst tubes and the secondary reformer enters the process gas boiler where saturated steam is produced on the shell side while cooling the gas in the process tubes.
SCHMIDT'SCHE® Process Gas Boilers operate in natural circulation and are connected to the steam drum via downcomers and risers where steam and water are separated.
- Thin, flexible or super flexible tube sheets.
- Metal dusting resistance.
- Two bypass designs to control gas outlet temperature (hot and cold bypass).
- Full penetration, crevice-free tube to tube sheet welding to prevent crevice corrosion.
- Single-or twin-compartment design.
- Inlet tube sheet protected by ferrules and refractory lining.
SCHMIDT'SCHE® VERTICAL PROCESS GAS BOILER
SCHMIDT'SCHE® Vertical Process Gas Boilers are the solution to counteract a common problem in conventional ammonia plants:
Most of the world's ammonia plants are equipped with either one or two vertical bayonet-type water-tube process gas boilers which are installed downstream of the secondary reformer. This creates several reliability issues, in particular:
- Sludge deposition in the pocket of the bayonets
- Erosion and corrosion of the tubes
- Overheating vibration
- Damage to the tube bundles of these boilers is the main cause of unexpected shut-downs in ammonia plants; the tube bundle has to be completely replaced on a regular basis.
We have pooled our respective superior process understanding, as well as excellence in heat transfer component design and fabrication, to apply our unique Double Tube & Oval Header technology platform in ammonia plants as a replacement for existing waste heat boilers downstream of the secondary reformer.
The SCHMIDT'SCHE® Vertical Process Gas Boiler is designed to replace the existing boiler, using the existing foundations and with minimal modifications to the existing plant.
OUR ANSWER FOR VERTICAL PROCESS GAS BOILERS
The unique SCHMIDT'SCHE® Double Tube & Oval Header technology platform
Challenging and sophisticated requirements need individual and proven solutions. We apply our unique SCHMIDT’SCHE® Double Tube & Oval Header technology platform for process gas boilers in steam reforming processes.
This technology platform has been utilized in the ethylene industry for decades and has successfully been adapted for the steam reforming industry as well.
Double Tube & Oval Header Technology Platform
- Aerodynamically optimized funnel shaped tube inlets together with intensively cooled oval headers provide the best possible protection against tube inlet erosion and formation of gas side deposits.
- The system is able to compensate for uneven gas flow distribution, leading to optimized heat recovery results.
- Mechanical and thermal stresses are reduced by thin-walled oval headers which thereby protect the magnetite layer on the cooling tubes to ensure operational longevity.
- High cooling water flow velocities ensure maximum cooling of the gas contacted surface and ensure the removal and transport of particles.
- Tried and tested design principle for more than 60 years with many plants operating for over 20 years without one single failure. This results in low maintenance efforts.
FOR AMMONIA PLANTS
- No alternation in plant configuration.
- Re-use of existing foundations.
- Short transfer line between secondary reformer and boiler.
- Water-cooled tube sheet, no use of refractory.
- No sludge deposition.
- Low tube skin temperature.
- No crevice corrosion.
- Thermal expansion compensation.