Water and Steam Pressure-Relief Systems
The task of water and steam pressure-relief systems consists of the following:
- relief of high-pressure water, steam and water-steam mixtures
- separation of water and steam in a drainage flash tank
- draining off the water, in an eddy-free flow and if required cooled down in a collecting tank
- removal of the steam via an exhaust pipe and a blow-off silencer into the atmosphere
During the pressure reduction of high-pressure hot water, considerable vaporization heat is emitted, forming a water-steam mixture which is separated into the individual phases. This phase separation occurs in the drainage flash tank through which the remaining condensate is led into a collecting tank and the generated steam is carried off via an exhaust pipe and a subsequent blow-off silencer into the open air.
Throttle systems are used in order to ensure a low-noise pressure reduction of the medium to the pressure level prevailing in the tank. A multistage throttle is radially flowed through. The number of stages depends on the amount of the pre-pressure and the noise reduction required.
The dimensions of the flash tank depend on the type (tangential or gravity relief tank), the mass flow rates occurring as well as on the thermodynamic state quantities. The phase separation in the tank is sustained by inserts like deflectors, flow chicanes and demister packages.
A complete condensate system consists of the main components pressure relief and condensate tanks, blow-off silencers and – besides the exhaust pipe – a multitude of pipes which are adapted to each other with respect to their dimensions, operating behaviour and acoustic effects.
The advantage of our offer to supply complete water-steam pressure relief systems is that it ensures an integrated plant optimization, free of intersection points and designed according to the requirements of process engineering, acoustics, standards required for the construction of pressure tanks as well as the statics of the whole system.
The typical scope of services of the basic engineering comprises:
- Process engineering design with determination of all main dimensions, cross-sections and volumes
- Providing an acoustic concept, including the design of noise reducing flash tank inserts as well as the design of the blow-off silencer
- Determination of all equipment parts and of the construction of the individual components
- Design of the acoustic and thermal insulation
- A support, guidance and expansion concept for all construction components with evidence of stability
For designing the complete system we use state-of-the-art computer-aided tools in three-dimensional construction. Parallel to the three-dimensional virtualization in the CAD system, automatic cross-linking is carried out in which the tension and expansion calculations are done by means of the FEM analysis based on given exterior end conditions, such as pipe connection and wind forces, interior pressures and temperature ranges.
The complete system is designed according to an agreed and approved pre-documentation. The system is delivered to the construction site after cost optimization of transport and assembly dimensions.
The typical documentation comprises:
- Data sheets for all system parts with principal design data of the individual components
- Layout drawings with all components including indications on:
- main dimensions
- platform levels
- loads applied, forces and expansions indicated in x, y, and z-directions
- manufacturer’s and purchase instructions
- welding prerequisites
- Quality and manufacturing documentation