Steam Boiler Quiz

Atomization is the process of breaking up fuel into fine particles to ensure good combustion. It involves converting the fuel into a fine spray or mist, which increases the surface area of the fuel and allows for better mixing with air. This promotes efficient combustion by facilitating the rapid and uniform burning of the fuel particles. Atomization is commonly used in various combustion systems, such as in internal combustion engines and industrial burners, to enhance fuel-air mixing and improve combustion efficiency.

The purpose of a peep hole in the boiler casing is to examine the condition of the flame. This is important because the flame is a crucial element in the combustion process of the boiler. By being able to observe the flame through the peep hole, operators can ensure that it is burning efficiently and without any issues such as excessive smoke or improper combustion. This helps in maintaining the overall performance and safety of the boiler.

Automatic boilers have combustion control systems that are designed to prevent immediate burner ignition after a normal or safety shutdown. This is done in order to allow time for the furnace to be purged. Purging the furnace means removing any remaining gases or impurities from the combustion chamber before igniting the burner again. This is important for safety reasons as it helps to prevent any potential explosions or accidents that could occur if there are still combustible gases present in the furnace.

The correct answer is "source of ignition for the explosive mixture". In order for an explosion to occur in the boiler furnace, all three conditions mentioned in the question must be met: an accumulation of unburned fuel, sufficient air to form an explosive mixture, and a source of ignition. Without a source of ignition, the explosive mixture will not ignite and therefore no explosion will occur. The other options listed (space large enough for explosion, ground in the burner ignition electrode, high steam demand on the boiler) are not directly related to the ignition of the explosive mixture.

Dissolved gases in the boiler feedwater can cause a corrosive condition in the boiler. When these gases, such as oxygen and carbon dioxide, are present in the water, they can react with the metal surfaces of the boiler, leading to corrosion. This corrosion can weaken the boiler structure and cause leaks or other damage. Therefore, it is important to remove dissolved gases from the feedwater to prevent the formation of a corrosive environment in the boiler.

The purpose of chemically treating boiler water is to achieve multiple goals. Firstly, it aims to reduce the formation of scale on the waterside of the boiler, which can hinder heat transfer and decrease efficiency. Secondly, it aims to minimize corrosion of the boiler metal, as corrosion can lead to equipment failure and leaks. Lastly, chemical treatment helps to reduce foaming and moisture carryover, which can cause operational issues and damage downstream equipment. Therefore, the correct answer is "all of the above."

High carbon monoxide content in the flue gas of a boiler indicates incomplete combustion. When fuel is not burned completely, it produces carbon monoxide instead of carbon dioxide. This can occur due to insufficient oxygen supply or improper mixing of fuel and air. Incomplete combustion is undesirable as it releases harmful pollutants into the atmosphere and reduces the overall efficiency of the combustion process.

Oil accumulation in boiler water can cause foaming and carryover from the boiler. Foaming occurs when the oil forms a layer on the water's surface, trapping steam bubbles and causing them to rise rapidly. This can lead to carryover, where the foaming water is carried over into the steam, resulting in contamination. Foaming and carryover can cause operational issues, such as reduced boiler efficiency, damage to downstream equipment, and increased maintenance requirements. Therefore, it is important to prevent oil accumulation in boiler water to avoid these problems.

Blowing down a gauge glass periodically helps to remove any sediment that may have accumulated on the glass. Sediment can obstruct the view and accuracy of the gauge glass, making it difficult to determine the water level in the steam drum. By removing the sediment, the gauge glass can provide a clear and accurate indication of the water level, ensuring the safe and efficient operation of the steam system.

If the fire box is not purged before attempting to light a fire in the boiler, it means that there may still be a buildup of flammable gases or fuel vapors present. When the fire is ignited, these gases can ignite and cause an explosion or flareback. Purging the fire box ensures that any potentially dangerous gases are removed before the fire is lit, reducing the risk of an explosion or flareback occurring.

The statement that heat transfer rate increases as temperature difference increases is correct. This is because the temperature difference between two objects determines the driving force for heat transfer. The greater the temperature difference, the greater the energy imbalance and the faster heat will flow from the higher temperature object to the lower temperature object. Therefore, the rate of heat transfer is directly proportional to the temperature difference.

The flash point of the fuel oil is the temperature at which it can ignite when exposed to an open flame or spark. When using the fuel oil for atomizing, it is important to determine the highest temperature to which the oil can be heated without reaching its flash point. This is because heating the oil beyond its flash point can lead to combustion and potentially cause a fire or explosion. Therefore, knowing the flash point helps ensure safe and efficient atomization of the fuel oil.

A pH value of 6 in boiler water indicates that the water is acidic. Acidic water can cause corrosion and damage to the boiler system. To prevent this, the pH should be raised to a normal level. This can be achieved by chemically treating the water to neutralize the acidity and bring the pH back to a safe range.

Strainers are installed in boiler fuel oil service lines to remove solids. This is important because solid particles can clog the fuel oil system, leading to reduced efficiency and potential damage to the boiler. By removing solids, the strainer helps to ensure a smooth flow of fuel oil, preventing blockages and maintaining the proper functioning of the boiler system.

When boiler water is chemically treated, reactions occur that produce by-products or impurities. These by-products and impurities can accumulate in the boiler over time, leading to various issues such as reduced efficiency and increased corrosion. To prevent these problems and maintain optimal boiler performance, regular removal of the accumulated by-products and impurities is necessary. This process is known as boiler blow down, where a portion of the boiler water is discharged to remove the contaminants. Therefore, the end product of reactions occurring during chemical treatment increases the need for boiler blow down.

As the pH of the boiler water approaches zero, it indicates a high concentration of hydrogen ions in the water. This high concentration of hydrogen ions makes the water acidic. Therefore, the correct answer is acidic.

The scanner installed in a modern combustion control system is responsible for detecting the presence of a fire. When the scanner senses that the fire has gone out, it triggers the system to cut off the fuel supply. This is done to prevent any potential hazards or accidents that may occur if fuel continues to be supplied without a fire present.

The correct answer is "steam has formed and all air is vented." When raising steam on a cold boiler, it is important to ensure that all air is vented from the system before closing the air vent. This is because air in the boiler can cause inefficiencies and potentially damage the boiler. Once steam has formed and all air is vented, it indicates that the system is properly filled with steam and ready for operation, allowing the air vent to be closed.

Failure to remove calcium and magnesium from the feedwater before it reaches the boiler can result in scaling. Scaling occurs when these minerals precipitate out of the water and form a hard, crusty layer on the inside of the boiler tubes. This layer reduces the efficiency of heat transfer and can eventually lead to overheating and failure of the tubes. Therefore, it is crucial to remove these minerals through water treatment processes to prevent scaling and maintain the proper functioning of the boiler.

If the low water level alarm sounds on an automatically fired boiler and the low water cut out fails to function, securing the fire is the correct action to take. By securing the fire, the fuel supply to the boiler is shut off, preventing further heat and pressure buildup. This helps to minimize damage to the boiler tubes, as continued firing without sufficient water can cause overheating and potentially lead to a catastrophic failure. It is important to secure the fire promptly to prevent any further damage or safety hazards.

Oxygen and carbon dioxide are the two common gases that dissolve in boiler water and cause corrosion on the internal parts of the boiler. Oxygen can lead to corrosion by reacting with the metal surfaces, while carbon dioxide can form carbonic acid when dissolved in water, which can also corrode the boiler. Therefore, the presence of these two gases in the boiler water can result in the deterioration of the internal parts of the boiler.

Keeping the steam line drained and insulated is the best way to prevent steam line water hammer. Water hammer occurs when steam condenses rapidly, causing a sudden pressure increase and resulting in a loud banging noise. By keeping the line drained, any accumulated condensate is removed, reducing the chances of water hammer. Additionally, insulating the steam line helps to maintain a constant temperature, preventing rapid condensation and minimizing the risk of water hammer.

Treating the water with chemical scavengers is the correct answer because chemical scavengers are substances that can react with dissolved oxygen and remove it from the boiler water. These scavengers can chemically react with the oxygen molecules, converting them into harmless compounds that do not pose a risk to the boiler system. This method is commonly used in boiler water treatment to prevent corrosion and damage caused by dissolved oxygen.

When a boiler is being cooled down, the temperature of the steam and water inside the drum decreases, causing a decrease in pressure. If the air vent is not opened, this decrease in pressure can create a vacuum inside the steam drum. Opening the air vent allows air to enter the drum, preventing the formation of a vacuum. This is important because a vacuum can cause damage to the boiler and its components.

Bunker "C" fuel oil is a heavy fuel oil with high viscosity. When it is heated prior to atomization, the heat causes the oil to become less viscous, meaning it flows more easily. This is important for efficient combustion in engines or burners, as reduced viscosity allows for better atomization and more complete combustion. Therefore, heating bunker "C" fuel oil reduces its viscosity, making it easier to handle and burn effectively.

Treatment of boiler feedwater is necessary to prevent waterside scale deposits. When the feedwater contains high levels of hardness, minerals such as calcium and magnesium can precipitate out of the water and form scale deposits on the internal surfaces of the boiler. These scale deposits can reduce heat transfer efficiency, restrict water flow, and ultimately lead to boiler failure. Therefore, treating the feedwater to remove or control hardness is essential in order to prevent the formation of scale deposits and ensure the efficient and safe operation of the boiler.

To minimize metal corrosion, boiler water is best kept alkaline. This is because alkaline conditions help to neutralize any acidic substances present in the water, preventing them from corroding the metal surfaces of the boiler. Alkaline water also forms a protective layer on the metal, acting as a barrier against corrosion. Keeping the water alkaline helps to maintain the integrity and longevity of the boiler system.

A boiler safety valve must be capable of remaining open until excess pressure in the steam drum is relieved in order to prevent a catastrophic failure of the boiler. If the pressure in the steam drum exceeds safe levels, the safety valve opens to release the excess pressure and prevent any damage or explosion. This ensures the safety of the boiler and the surrounding equipment and personnel.

Incomplete combustion occurs when there is not enough oxygen present for the complete oxidation of a fuel. In this case, insufficient air results in the production of carbon monoxide (CO) instead of carbon dioxide (CO2). Carbon monoxide is a toxic gas that is colorless, odorless, and tasteless. It is produced when carbon-containing fuels, such as gasoline, coal, or wood, do not burn completely. Carbon monoxide can be harmful when inhaled, as it binds to hemoglobin in the blood, reducing its ability to transport oxygen. Therefore, the excess amount of carbon monoxide is the correct answer.

Carbon dioxide is one of the most corrosive substances in boiler water. When carbon dioxide dissolves in water, it forms carbonic acid, which can corrode the metal surfaces of the boiler. This corrosion can lead to the deterioration of the boiler's structural integrity and reduce its efficiency. Therefore, it is important to control the levels of carbon dioxide in boiler water to prevent corrosion and maintain the proper functioning of the boiler system.

A positive displacement rotary pump is the most suitable choice for fuel oil service because it is designed to handle viscous fluids like fuel oil. This type of pump operates by trapping fluid between rotating components and the pump casing, creating a continuous flow. It is capable of delivering a consistent and steady flow rate, which is important for fuel oil applications. Additionally, positive displacement rotary pumps are known for their durability and ability to handle high pressures, making them suitable for the demanding conditions often found in fuel oil service.

Infrequent bottom blows refers to the process of removing accumulated solids from the bottom of a boiler. If bottom blows are infrequent, these solids can build up and increase the concentration of total dissolved solids in the water. This can lead to various issues such as reduced boiler efficiency, corrosion, and scaling. Therefore, infrequent bottom blows can be a possible cause for the increase in total dissolved solids concentration in the water in a boiler.

Flame scanners are used in combustion control systems to secure the fuel oil supply in the event of a flame failure. This means that if the flame scanner detects that the flame has gone out, it will take measures to ensure that the fuel oil supply is shut off to prevent any potential hazards or accidents. This is an important safety feature as it helps to prevent the accumulation of fuel oil in the system and reduces the risk of fire or explosions.

The presence of sulfur in the fuel oil can lead to corrosion in the fireside of the boiler. Sulfur, when burned, forms sulfur dioxide (SO2) which can combine with moisture in the flue gas to form sulfuric acid (H2SO4). This acid can then condense on the fireside surfaces of the boiler, leading to corrosion. Corrosion can weaken the boiler structure and cause leaks, reducing the efficiency and lifespan of the boiler.

Phosphates are used in the chemical treatment of boiler water because they have the ability to convert scale forming salts into relatively harmless sludge. This helps to prevent the formation of scale deposits on the surfaces of the boiler, which can reduce its efficiency and lead to costly repairs. By converting these salts into sludge, the phosphates make it easier to remove them from the system, ensuring that the boiler operates smoothly and efficiently.

Foaming in the boiler water is caused by excessive suspended solids. When the water in the boiler contains high levels of suspended solids, such as impurities or contaminants, it can lead to the formation of foam. This foam can interfere with the proper functioning of the boiler, causing issues such as reduced heat transfer, increased corrosion, and even boiler carryover. Therefore, it is important to control and minimize the levels of suspended solids in the boiler water to prevent foaming and maintain efficient boiler operation.

Highly alkaline boiler water can lead to caustic embrittlement. Caustic embrittlement is a condition where the metal of the boiler becomes brittle and prone to cracking due to the presence of high levels of alkaline substances, such as sodium hydroxide, in the water. This can occur when the pH of the water exceeds a certain threshold, causing the metal to undergo a process called alkaline attack. This can result in serious damage to the boiler and potential safety hazards.

The photoelectric cell installed in an automatically fired boiler is designed to sense light from the burner flame. This is important for combustion safety controls as it allows the system to monitor the presence and intensity of the flame. By sensing the light from the burner flame, the photoelectric cell can provide feedback to the control circuit, allowing it to make adjustments and ensure the proper functioning of the boiler.

The fire point is the lowest temperature at which fuel oil gives off sufficient vapors to burn continuously when ignited. This temperature is higher than the flash point, which is the lowest temperature at which fuel oil gives off sufficient vapors to ignite momentarily when exposed to an open flame. The auto ignition temperature refers to the lowest temperature at which fuel oil can spontaneously ignite without an external ignition source. Therefore, the fire point is the most appropriate term to define the given scenario.

Sulfur is a significant combustible element in fuel oil and is a major source of boiler corrosion. When fuel oil containing sulfur is burned, sulfur dioxide is produced. This sulfur dioxide combines with water vapor in the flue gas to form sulfuric acid, which is highly corrosive. This acid can corrode the boiler's metal surfaces, leading to damage and reduced efficiency. Therefore, sulfur is the correct answer as it is a major contributor to boiler corrosion in fuel oil.

The purpose of a deaerator feedwater is to prevent corrosion in the boiler. Corrosion in the boiler can lead to damage and reduce the efficiency of the system. The deaerator removes dissolved oxygen and other gases from the feedwater, reducing the potential for corrosion. This helps to prolong the lifespan of the boiler and maintain its performance.

When carbon dioxide gas dissolves in boiler water, it forms carbonic acid. This carbonic acid is dangerous in modern power boilers because it attacks the waterside. This means that it corrodes and damages the surfaces of the boiler, leading to potential leaks and structural integrity issues. Therefore, the presence of carbonic acid in the boiler water can cause significant damage to the boiler system.

A higher than normal boiler stack temperature usually indicates a dirty fireside. This means that there is a buildup of soot, ash, or other deposits on the fireside surfaces of the boiler. This buildup acts as an insulator, reducing heat transfer and causing the stack temperature to rise. It can be caused by factors such as inefficient combustion, poor fuel quality, or inadequate maintenance. Regular cleaning and maintenance of the fireside surfaces are necessary to prevent this buildup and maintain optimal boiler performance.

A dirty flame scanner in automated boiler operations will most likely result in securing fuel oil to the burner. This is because a dirty flame scanner may not be able to accurately detect the presence of a flame, leading to the system shutting off the fuel supply as a safety measure. By securing the fuel oil to the burner, the risk of a potential fire or explosion is minimized.

Low stack gas temperature should be avoided in order to reduce the formation of sulfuric acid. When the stack gas temperature is low, the water vapor present in the flue gas can condense and combine with sulfur dioxide (SO2) to form sulfuric acid (H2SO4). This can lead to the formation of acid rain, which is harmful to the environment and can cause damage to buildings and infrastructure. By maintaining a higher stack gas temperature, the water vapor is less likely to condense, reducing the formation of sulfuric acid.