Steam Desuperheaters

Steam Desuperheaters

Most modern boilers generate steam at high pressures & temperatures. High pressure steam has lesser volume than steam at atmospheric pressure, thereby translating into smaller boiler size & lower diameter of steam piping. Also, high temperature (superheated) steam has more energy, which translates into higher efficiency for power generating steam turbines.

On the other hand, all process industries use low pressure low temperature saturated steam, primarily due to the following reasons:

  • Saturated steam has the highest heat transfer efficiency.
  • Lower pressures & temperatures translate into thinner pipes, lighter flanges & less expensive materials thereby significantly reducing initial plant cost.

In any industry, steam is required at different locations, but the required steam pressure & temperature at each location varies according to the application. Therefore, high pressure superheated steam is generated at a central location (boiler), distributed to various locations in the plant through a steam piping network, and then reduced to the operating pressure & temperature just upstream of the usage points.

MTECK steam desuperheaters are available in the following configurations:

Mechanical Spray Desuperheater (MSD or MINI)

The DeFlo Mini is one of the most basic type of Desuperheaters which utilizes a MTECK HP-Globe Control valve as its cooling water control valve. It consists of fixed jets arranged to face the steam flow direction through the periphery of the Desuperheater sleeve. It works well in stable conditions where the steam flow turn-down is a maximum of 4:1.

The Stainless Steel sleeve acts as a thermal liner and is of the size of the steam pipe ID hence eliminating localized velocities created by many competitor designs.

For low turndown applications or in oversized pipes a venturi sleeve can be provided which creates local turbulence and velocity for effective mixing of the water with the steam.

For MTECK to design an efficient Mechanical Spray Desuperheater, please provide below information as a minimum:

  • Operating pressure of steam
  • Maximum inlet temperature of steam~
  • Required outlet temperature of steam
  • Steam flow rate~
  • Available cooling water pressure
  • Available cooling water temperature
    ~You may provide all possible values for these parameters

Variable Spray Desuperheater (VSD)

The DeFlo VSD integrates the precision and simplicity of a Control Valve into a Desuperheater to attain maximum turn-down, responsiveness and accurate control.

For a maximum efficiency, the DeFlo VSD atomizes the cooling fluid (water in most cases) at the vena contracta just downstream of the throttling point and right at the injection point. The special design of the spray retainer or nozzle ensures a hollow swirling cone pattern of the fluid which provides most effective atomization, and the particles are dispersed and distributed evenly across the flow path of steam in order to provide effective Desuperheating.

The total cooling water differential pressure is available at the throttling point thereby optimizing the atomization even further.

The integrated MTECK DeFlo VSD:

  • No Additional cooling water control valve required.
  • Class V shut-off available.
  • Probe installation which does not influence the piping geometry or velocity of the steam.
  • Lower maintenance cost: No additional valve to service, integrated lightweight & compact high performance actuator.

Steam Conditioning Valve (SCV)

This combined Pressure Reducing and Desuperheating control valve is a compact yet effective and carefully designed instrument. The MTECK DeFlo SCV eliminates all common issues faced by combined type steam conditioning valves.

The SCV is the most efficient way of steam conditioning where the water is injected in a highly turbulent area to ensure most efficient water to steam mixing. The DeFlo SCV are available in Standard, Angle and Expanded outlet configurations.

No special expertise is required to operate or maintain the MTECK DeFlo SCV as it utilizes most parts of our Standard HP-Globe control valve with an addition of a Thermal Desuperheating Sleeve at its outlet. This spray method protects the valve belly from pitting and thermal shocks/stresses unlike most of the designs available in market. This also reduces maintenance costs of the SCV as the Valve and Trim life is greatly prolonged.

With an extensive knowledge of Control Valves and Desuperheating units, MTECK is one of only a handful manufacturers specialising in the field of Pressure Reducing and Desuperheating.

Pressure Reducing & Desuperheating Station (PRDS)

MTECK PRDS is a modular steam conditioning unit to reduce the steam pressure & temperature at the point of usage and it can be directly installed into client’s existing steam network.

MTECK PRDS is specifically sized and designed to meet client’s requirements and is supplied pre-fabricated or as a module to plug/install into client’s existing steam system.

Some applications of PRDS are as below:

  • PRDS for process heating / cooling applications in sugar, food, textile, paper etc. plants
  • Deaerator, Ejector PRDS for boiler
  • Turbine bypass PRDS

Steam Desuperheaters Specification