Steam Boilers

Hydro Flow has the capability to manage all types of boiler system water treatment needs. The Hydro Flow team has expertise in water pre-treatment equipment, chemical treatment programs, boiler system water treatment service and management as well as chemical dosing equipment design, installation and commissioning.

All scales of industry use steam as a heat exchange and process activation medium; from a package boiler in a dry cleaners through to large high pressure boilers at power stations. Steam applications can be direct injection, process heating or power generating via turbines.

  • water tube boilers
  • fire tube boilers
  • condensing boilers
  • electric boilers

Hydro Flow works closely with utilities operations personnel and management, boiler mechanics and maintenance facilities companies to ensure excellence in operational considerations on the water side that enhance the efficiencies of the mechanical and heating functions of the boiler.

steam boilersFigure 1 – Typical industrial steam boiler circuit

Water Supply -> water pre-treatment (softening/ demineralisation) à preheating -> de-aeration -> ( superheating) (condensate return) -> makeup to boiler -> boiler

Design of a steam boiler system is dependent upon the requirements of the process and considerations such as pressure, temperature and flow load required by the plant.

On the water side of a boiler system, it is very important to understand the system conditions in order to provide the most effective and energy efficient water treatment solutions.

 

Hydro Flow focus on the following areas when designing and managing a BOILER WATER TREATMENT program:

  • Make up water treatment to remove impurities that have scaling potential and thus reduce any impact on heat transfer conditions.
  • Use of oxygen scavenging treatments that are complimentary to mechanical removal methods in order to minimise dissolved gases in the feedwater.
  • Energy balance by suitable control of blowdown to maintain a satisfactory level of cycles ( total dissolved solids concentration ratio) in the boiler water. Poor control leads to increase fuel costs, losses in water, heat and chemicals.
  • Treatment of steam space (overheads) pipework and processing vessels along with condensate return pipe work from corrosion attack.
  • Liaising with boiler operator and facilities personnel to ensure optimal operating conditions are maintained.

Boiler System

Make Up and Feedwater Water Quality

A boiler, by nature, concentrates any materials or impurities that are present in the feedwater when producing steam.

Make up water can vary across different regions and may require a number of different pre-treatment options to remove impurities and achieve an acceptable quality of water. In general, the higher the operating pressure of the boiler required the higher the purity of feedwater required.

Equipment such as softeners, demineralisers, carbon filters and reverse osmosis may be employed to remove the known impurities and reduce the impact of scaling and depositing materials from building up on the boiler heat transfer areas (tubes).

Hydro Flow can assist in the evaluation of the makeup water quality along with the design, installation, commissioning and management of the required equipment.

Pre-heating and Deaeration

Pre-heating of feedwater is often used to prepare the makeup water for use in the boiler and minimise thermal shock along with minimising fuel load . It can be heated by waste heat streams, return condensate, heating coils or other elements.

Dissolved gases in the feedwater can promote corrosion issues in the boiler. Deaeration via heat and mechanically allows the liberation of the dissolved gases prior to entering the boiler. The higher the pressure of the boiler, the more critical it is to remove these impurities.

To ensure the most effective removal of dissolved gases, oxygen scavenging chemicals are used to reduce residuals to a very low level (ppb) .

Boiler Water

Boiler water concentrates as the steam is produced. A balance of conducting blowdown or purging of boiler water to remove the build-up of total dissolved solids creates a need for new makeup water to enter the system.

Hydro Flow has extensive experience in managing effective application of treatment programs for boiler water systems. The programs are designed to balance between dispering scaling elements and minimising the development of a corrosive environment.

Condensate

Energy and water can be conserved if condensate is able to be returned to the boiler as a supplementary makeup and heat source.

Condensate can be naturally corrosive due to the dissolved carbon dioxide produced in the steaming process. In general, a chemical treatment that carries over with the steam is recommended to provide protection for condensate return pipe work and minimise ingress of corrosion product to the boiler.

Protection of the pipe work infrastructure also minimises any additional impurities such as iron and copper returning to the boiler system in the feedwater.