Table of Contents
- 1 How are water tubes attached to drums headers?
- 2 Why no Vapour bubble should flow along with water from the drum to the water tube Downcomers in natural circulation?
- 3 Why the drums are used in water tube boiler?
- 4 Which material is used for boiler tubes?
- 5 What is the difference between forced circulation and natural circulation?
- 6 What is circulation ratio?
- 7 How are downcomer and riser tubes connected in a steam drum?
- 8 Which is the best way to roll a water tube?
How are water tubes attached to drums headers?
The earlier water tubes include an arrangement of the only drum by headers that are connected by short, straight tubes and bent pipes. The hot gases will flow over the pipes in one go only. This article discusses an overview of water tube boiler, components, and its types.
Why no Vapour bubble should flow along with water from the drum to the water tube Downcomers in natural circulation?
No vapour bubble should flow along with saturated water from the drum to the down comers. This will reduce the density difference and the pressure head for natural circulation.
Why is circulation ratio kept over 6?
The value of circulation ratio varies from 6 to 30 in industrial boilers. Circulation ratio for utility high pressure boilers is between 6 to 9. Circulation ratio is higher side as the density difference between steam & water is high. Medium pressure industrial boilers adopted higher circulation ratio.
What chemical is fed to the deaerator?
The type of chemical added depends on whether the location uses a volatile or non-volatile water treatment program. Most lower pressure systems (lower than 650 psi (4,500 kPa)) use non-volatile treatment programs. The most commonly used oxygen scavenger for lower pressure systems is sodium sulfite (Na2SO3).
Why the drums are used in water tube boiler?
A steam drum is a standard feature of a water-tube boiler. The drum stores the steam generated in the water tubes and acts as a phase-separator for the steam/water mixture. The difference in densities between hot and cold water helps in the accumulation of the “hotter”-water/and saturated-steam into the steam-drum.
Which material is used for boiler tubes?
Boiler tubes are seamless tubes and are made of either carbon steel or alloy steel. They are widely used in steam boilers, for power generation, in fossil fuel plants, industrial processing plants, electric power plants, etc.
What does tube rolling mean?
Tube rolling is the process of trying out a number of tubes in the same spot in an amplifier and selecting the one that sounds best to you. This can be very helpful in optimizing the tone of the amplifier. CAUTION: Tube amplifiers run on dangerous high-voltages and the tubes get very hot during operation.
What is the function of steam drum?
A steam drum is a standard feature of a water-tube boiler. It is a reservoir of water/steam at the top end of the water tubes. The drum stores the steam generated in the water tubes and acts as a phase-separator for the steam/water mixture.
What is the difference between forced circulation and natural circulation?
The difference between the forced circulation boiler and the natural circulation boiler is that the circulation between the downcomer of the natural circulation boiler and the heating surface is generated by the natural indenter between the two, and the forced circulation boiler is forced by the furnace water …
What is circulation ratio?
Circulation ratio is defined as the ratio of the mass of the steam/water mixture to the mass of steam at the exit of the evaporator tube field. A circulation ratio of 5:1 means there is five times as much water flowing through the downcomer and into the tubes than steam being generated in the tubes.
What is the advantage of a pressurized deaerator over an atmospheric deaerator?
Price on atmospheric unit is slightly lower than a pressurized unit. The pressurized unit is more flexible, the atmospheric system costs less and usually has lower vent losses.
How big of an expander do I need for a drum tube?
Choose the appropriate expander; tube hole tolerances should be considered (figure plus 1/32”), the roll length should allow you to expand a minimum of 3/16” to a maximum of 1/2” beyond the tube sheet or seat, as in a drum or counter-bored tube hole.
How are downcomer and riser tubes connected in a steam drum?
Note that the steam drum plate into which the downcomer and riser tubes are connected is thicker than the rest of the drum. The tubes are rolled into this plate like the tubes in an exchanger are rolled into the tube sheet. Expanded tube connections are generally suitable for pressures up to 1200 psia.
Which is the best way to roll a water tube?
Set the rolls and tighten the mandrel so that the space between the end of the tube and the front of the flare roll will allow for rolling the tube three-fourths tight while producing a suitable flare.
How is the ear tube pushed into the ear canal?
Extrusion is the process of the ear tube being slowly pushed out of the ear drum into the ear canal. In rare cases, the tube falls into the middle ear, and the ear drum heals over the tube. This process is called intrusion.