High-pressure boilers are described as single-drum or bi-drum boilers. At first, the Sterling boilers were equipped with four drums that were on the lower one and three on top, connected with a tube bank. The three-drum and two-drum designs were developed. Today’s bi-drum boilers are specifically designed to handle the large flow, pressure, and temperature.

Bi-drum Boiler

Modern bi-drum boilers are utilized both for power generation as well as processes steam generators. To generate power the type boiler is utilized as high as 100 MW. These are basically non-reheat units that are being destroyed because of the high heat rates of this plant. For steam generation plants in the process, this kind of bi-drum boiler is most commonly used because it is able to handle high load fluctuations and react to changes in load speed much faster than a mono drum boiler.

The two drums inside these kinds of boilers are joined via a lot of heat transfer convective tubes, also known as bank tubes or boiler tubes. The bank tubes of a bi-drum boiler are around 11,000 in number. The bank tubes as well as the bottom drum will contain water, the volume of which will be equal to the normal working levels of the water inside the upper drum. The huge volume of water that is available within the bi-drum boiler allows it to adapt to large load shifts. The bank tubes on the furnace side, where flue gases are introduced into the bank tubes function as raisers and are stocked with the steam-water mix. The number of bank tubes that are located along the flue gas route that acts as raiser tubes can vary dependent on the load. The remaining row of tubes is downcomer tubes that connect the drums that are lower and the upper. Another key aspect in the boiler’s bank is the temperature of flue gas in the bank tubes stays virtually constant across all boiler operating loads. In the event of rapid or slow load shifts, the number of riser tube rows increase while the downcomer tube rows decrease so that steam can be pumped immediately within the steam drum when loads increase.

Bank tubes can be put into the lower and upper drum holes and then expanded to stand up to the pressure of operation. Some designers prefer to join them with both the drums, both lower and upper. Bi-drum boilers can be bottom as well as top supported designs.

Single Drum Boiler

Single drum boilers will be utilized mostly to generate power. As supercritical pressure boilers come into service, even the single drum is eliminated. This type of boiler comes with advantages in that it can be designed to operate at extremely high flow, pressure, and temperature. The downcomers are joined to the drum and are pipes that are sized and numbers two, to allow circulation through the furnace’s wall tubes. Single drum boilers can be utilized for both non-reheat and heating boilers. A single drum boiler design is suitable for natural circulation systems with high pressure and forced-circulation boilers. Single drum boilers are usually built with top-supported support only.

Bi-Drum Boiler Tube Expansion

A Bi-drum boiler is a multi-faceted two-drum water tube-style boiler fired with solid fuel that is generally utilized to create high steam pressure that is required to generate power for incidental purposes or cogeneration. It can also be utilized in saturated steam applications that require a continuous operation on extremely choking fuels. The boiler is durable and is able to operate all year round. Furthermore, as it is a small amount of water it is able to respond quickly to any changes in load or heating inputs. Subzero Tube Tools Pvt Ltd is one of the best tube expansion manufacturers in Mumbai