High Pressure Steam Boiler: Features, Perks, and When to Replace

ByMcKenna Boiler

Boilers have become an everyday thing for commercial and industrial activities. A high pressure steam boiler has tons of great benefits in the industry, which is why business owners are making use of these to get ahead in the market.

But what are the basic things that a high pressure steam boiler has?

Basic Features of a High Pressure Steam Boiler

  • Increased number of small diameter tubes

It is pretty normal to know that the surface-to-area volume ratio, which is the area density, generally increases via the use of small-diameter tubes. This helps in a high rate of heat transfer to the water flowing right inside the tubes. This is why a large number of small-density tubes are there in a zigzag manner and are used for the forced circulation of water. Not to mention that the use of short tubes lowers the pressure loss so to offer a better quality of steam.

  • Forced circulation of water

This is the good thing about all the modern-day high pressure steam boiler models. The forced circulation of water remains the same, courtesy of pumps. It also increases the help of pumps. Additionally, it also increases the main temperature of heat addition and evaporation capacity of the whole boiler.

  • Compactness

The high rate of heat transfer right inside the boiler can reduce the overall size of the boiler, resulting in the boiler becoming compact.

  • Improved heating mode

High-pressure steam boiler systems make use of heat transfer via radiation along with convection and conduction. The complete heat-receiving equipment gets divided into different parts. All that can be easily located in different zones of the furnaces for more efficient heat transfer to the water circuit.

  • Intensive heating

The furnace temperature for high pressure steam boiler models is already high, and 70 percent of heat is transferred to the water via radiation. This seems to be the faster way of heat transfer.

  • High temperature and steam pressure

Steam is usually generated at a pressure of 80 to 300 bars with a temperature of 450C to 585C with two superheaters in series. The use of this kind of steam can be very suitable for power generation. It also increases the thermal efficiency of the plant while reducing moisture content in low-pressure stages of expansion in the turbine.

Benefits of High Pressure Steam Boiler

  • This requires less heat of vaporization in comparison.
  • They make use of the forced circulation of water to make sure that the positive circulation of water increased evaporative capacity.
  • These are generally compact and require less floor space.
  • Because the velocity of water is high, the scale formation tendency gets minimized.
  • The overall efficiency of the plant gets increased.
  • All of the parts get uniformly heated which minimizes the danger of overheating.
  • Making use of a high pressure steam boiler, steam generation becomes economical.
  • It is easy to raise steam in order to meet the variable load requirements without using complicated control devices.

When to Consider Replacing a Boiler

Changes in Requirements

It is no secret that high pressure steam boiler requirements can change over the course of time. An oversized high-pressure steam boiler that is continuously operating at a low range is generally far less efficient in comparison to a unit that is in the perfect size for the load.

This is why investing in the right size of boiler can help in saving a lot of money while offering better overall performance. Improved efficient models, small models in terms of capacity, or even a couple of smaller steam boilers can operate in a more efficient manner, which generally depends on the situation. A supplier that has the right amount of knowledge can help in making all the right decisions.

While making a decision about whether to replace the boiler or not, all such things should be considered. This includes the current plant loads, future plant loads, and the technology that should be considered during the repair or replacement decision. A steam boiler that isn’t safe for use should be taken as a serious concern and should be made the absolute priority.

Safety Reasons

Safety concerns are pretty normal and are generally discovered during regular safety inspections and at the same time, licensed inspectors are responsible for examining the condition of the pressure vessel and the boiler safety devices. On top of the regular inspections, it is important to closely monitor boiler inspection. Here are some of the conditions to watch out for.

  • Exceeded Cycling

Generally, continuous starts and stops can increase the number of thermal cycles, to which, the pressure vessel is subjected to. An increase in thermal cycling and the associated stress can generally cause fatigue in a steel boiler.

  • High Stack Temperatures

If the temperature of the stack is unusually high, it implies that the heat transfer is quite poor and it is potentially unsafe conditions because of poor combustion, low water levels, or even poor water management.

  • Poor Combustion Rumbling/Tuning

In case the fuel or the airflow is improper, it can lead to noticeable surging and pulsations in the whole process. The possible causes for this include improper burner adjustment, issues with the combustion fan, and improper stack conditions or design.

  • Irregular Starting/Stopping

Irregular starting or stopping can be a strong indication that the operating controls are not functioning in a proper manner and that the safety controls have taken over. All such operating and safety devices along with their settings should be inspected by a technician with the right credentials.

High-pressure steam boiler safety issues generally manifest either from combustion side issues or waterside issues.

  • Poor removal of oxygen

In case the deaerator or the water treatment system doesn’t function, oxygen pitting on the surface of the tubes may result.

  • Water hardness

The development of internal scales on the tubes due to a failed water softener or because of incorrect softener settings. This layer of scale further impedes the transfer of heat and can cause overheating to a dangerous extent, which can normally be observed in the form of high stacked temperatures.

  • Quenching

Incomplete or improper water circulation within the boiler can lead to overheating in certain specific areas of the boiler. As soon as the overheated steel is quickly quenched or cooled, cracks might develop which can lead to tube failure.

  • Poor control of water chemistry

This can cause caustic embrittlement which can cause tubes to lose their key mechanical properties.

Economics

With time, steam boilers can become inefficient which can be a good reason for replacing a boiler. The cost of fuel can also play a major role in this issue. This cost of inefficiency gets increased significantly when fuel costs and operating hours move up. Even the smallest of improvements in efficiency can lead to major savings.

Another major economic consideration comes into play whenever boiler steam needs repairing or replacing. In the majority of cases, the cost of repair is high enough that replacement actually becomes a better financial decision. If for some reason, the parts are obsolete or if the service is not getting scheduled, the overall downtime impact can severely increase the cost of repair.

Once the overall cost of the steam boiler downtime becomes expensive, try installing a backup boiler to increase the overall reliability.