For steam trains, what kind of deaerator was used, if any?

What is a steam deaerator?

Deaerators are mechanical devices that remove dissolved gases from boiler feedwater. Deaeration protects the steam system from the effects of corrosive gases. It accomplishes this by reducing the concentration of dissolved oxygen and carbon dioxide to a level where corrosion is minimized.

What are the types of deaerator?

There are two basic types of deaerators, the tray-type and the spray-type: The tray-type (also called the cascade-type) includes a vertical domed deaeration section mounted on top of a horizontal cylindrical vessel which serves as the deaerated boiler feedwater storage tank.

Which chemical is used in deaerator?

Thermal deaerators

Dissolved carbon dioxide combines with water to form carbonic acid that may cause further corrosion. Most deaerators are designed to remove oxygen down to levels of 7 ppb by weight or less, as well as essentially eliminating carbon dioxide.

What is spray-type deaerator?

The Spray-Type Deaerator consists of a horizontal or vertical cylindrical vessel which serves as both the deaeration section and the boiler feedwater storage tank. The typical spray-type deaerator is a horizontal vessel which has a preheating section and a deaeration section. The two sections are separated by a baffle.

How does a tray type deaerator work?

Tray-type deaerators are designed with as many as 24tray tiers to permit an adequate surface exposure. By utilizing this design method, the same amount of water surface is exposed to the steam for gas release, regardless of inlet water temperature.

What is deaerator principle?

The Principle of Deaeration

Simply stated, the solubility of the gases in the water is decreased as the temperature of the water increases. The solubility of oxygen in water decreases as the water temperature increases.

Is a deaerator a pressure vessel?

Deaerators are large, insulated tank-car-shaped pressure vessels. They produce preheated boiler feedwater to help ensure efficient steam-plant operation. Deaerators come in numerous sizes and shapes, depending on boiler-plant design, capacity, and system pressure rating.

What do you mean by vent condenser *?

A vent condenser could condense the flashed steam, transfer its thermal energy to incoming makeup water, and then return it to the boiler. Energy is recovered in two forms: hotter makeup water and clean, distilled condensate ready for productive use in your operation.

What temperature should a deaerator be?

In most applications you are looking for 5-7 psi of pressure and a temperature of 225 to 227 degrees. This will ensure the DA Tank can remove these gases and get the water up to temperature before supplying it to the boiler.

Why do you need a deaerator?

The purpose of a deaerator is to reduce dissolved gases, particularly oxygen, to a low level and improve a plant’s thermal efficiency by raising the water temperature. In addition, deaerators provide feedwater storage and proper suction conditions for boiler feedwater pumps.

Where is deaerator located?

Deaerators are typically elevated in boiler rooms to help create head pressure on pumps located lower. This allows hotter water to be pumped without vapor locking should some steam get into the pump.

Why is pressure maintained in deaerator?

Steam pressure inside the deaerator has to be maintained to facilitate the removal of dissolved gases from water and also to provide adequate NPSH to boiler feed water pump. Deaerators are normally installed at high elevation in order to provide enough NPSH in the event of failure in steam pressure control also.

How do you pronounce deaerator?

Quote from Youtube video:Y ella derecha de ella.

How do you size a deaerator?

The receiver size on deaerators is typically based on the total system load (i.e., sum of all boilers fed by deaerator) with 10 minutes NET storage. If boiler and deaerator are on the same floor, enter a value of “0” for feet of head.

What is foaming in boiler?

Boiler water carry-over is the contamination of the steam with boiler-water solids. Bubbles or froth actually build up on the surface of the boiler water and pass out with the steam. This is called foaming and it is caused by high concentration of any solids in the boiler water.

What is sludge and scale?

If the precipitation takes place in the form of loose and slimy precipitate, it is called sludge. On the other hand, if the precipitated matter forms a hard, adhering crust/coating on the inner walls of the boiler, it is called scale.

What is carryover in a boiler?

Boiler carryover is when something other than clean steam leaves the boiler through the header. This often includes things like liquid, contaminants in vapor and even solids. Low pressure boilers are generally more susceptible to carryover but high pressure systems can have these issues as well.

What is boiler corrosion?

Boiler corrosion is the destruction of boiler metal. It occurs when the oxygen within the boiler dissolves into the water. The dissolved oxygen then causes a reaction with iron-rich (ferrous) boiler metal in a process known as oxidation. Deep holes and cavities develop within the metal.

What is the pH value of boiler water?

An important element of boiler feedwater treatment is controlling corrosion by keeping the boiler water slightly alkaline, between 7 and 9 on the pH scale.

What are boiler troubles?

Boiler troubles: Sludge, scale, priming and foaming, caustic embrittlement, boiler corrosion are collectively known as boiler troubles. A. Caustic Embrittlement: (Inter crystalline cracking of boiler metal) It is the intercrystalline cracking of boiler due to Na2CO3.

Which type of corrosion occur in boiler?

Galvanic corrosion occurs when a metal or alloy is electrically coupled to a different metal or alloy. The most common type of galvanic corrosion in a boiler system is caused by the contact of dissimilar metals, such as iron and copper. These differential cells can also be formed when deposits are present.

What are the 3 types of corrosion?


  • Uniform Corrosion. Uniform corrosion is considered an even attack across the surface of a material and is the most common type of corrosion. …
  • Pitting Corrosion. …
  • Crevice Corrosion. …
  • Intergranular Corrosion. …
  • Stress Corrosion Cracking (SCC) …
  • Galvanic Corrosion. …
  • Conclusion.

Why trisodium phosphate is used in boiler?

Trisodium phosphate (Na3PO4), also known as TSP, is a common boiler water conditioning chemical that establishes moderately alkaline conditions in the boiler to minimize corrosion and reduce scaling where hardness ingress occurs.

What does sulfite do in a boiler?

Sulfites. Sodium sulfite is generally used for the chemical removal of dissolved oxygen within the boiler water. To assure the rapid and complete removal of the oxygen entering the boiler feedwater system the concentration of sulfite in the boiler must be maintained at a minimum of 20 PPM (parts per million).

What is the pH of steam?

It comes into play with steam boilers because a pH between 7 and 9 (slightly alkaline) is just right. If the pH is lower than that, the water will start eating the pipes.

Is boiler water toxic?

Under certain conditions, it is theoretically possible that DEAE (or related compounds) in boiler water may be converted to nitrosamines, which are suspected human carcinogens.

What causes low pH in boiler water?

A low boilerwater pH is usually caused by contamination of the boiler feedwater, from sources such as hydrochloric or sulfuric acid from leaks in demineralizers and condenser leaks of cooling tower water.

What chemicals are used in boiler water?

The softening chemicals used include soda ash, caustic and various types of sodium phosphates. These chemicals react with calcium and magnesium compounds in the feed water. Sodium silicate is used to react selectively with magnesium hardness.

What is pH full form?

The letters pH stand for potential of hydrogen, since pH is effectively a measure of the concentration of hydrogen ions (that is, protons) in a substance. The pH scale was devised in 1923 by Danish biochemist Søren Peter Lauritz Sørensen (1868-1969).

What is alkalinity in boiler water?

The alkalinity is principally carbonate (CO3) or bicarbonate (HCO3) anions, which can be expressed in parts per million or as grains per gallon. One gpg equals 17.1 ppm. As the operating pressure in the boiler goes up, both the total dissolved solids and alkalinity should go down.

What are the five types of alkalinity of water?

Depending upon the pH of the water, alkalinity can exist in water in three basic forms: carbonate (CO3), bicarbonate (HCO3), or hydroxide (OH). Total alkalinity is the sum of these three forms.

What is P and M alkalinity in boiler?

p Alkalinity vs m Alkalinity

p alkalinity is the measurement of alkalinity given by hydroxide ions and half of the carbonate alkalinity. m alkalinity is the measurement of alkalinity given by hydroxide ions and total carbonate alkalinity.