4BE3 U6 C1 Obj 5 EMH
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EASY What happens to the steam in the condenser section of a deaerator?

  • It is used to control the pressure
  • It is used to heat the water
  • It condenses and falls back into the deaerator (correct)
  • It is vented to the atmosphere

What is the purpose of the steam pressure controller?

  • To regulate the steam flow (correct)
  • To vent the gases to the atmosphere
  • To heat the water
  • To control the level of water in the deaerator

What is the function of the overflow valve?

  • To regulate the water level (correct)
  • To control the pressure in the deaerator
  • To heat the water
  • To vent the gases to the atmosphere

What is the purpose of the level alarm low?

<p>To indicate low water level (D)</p> Signup and view all the answers

How does a tray-type deaerator work?

<p>By trickling water down over a series of trays (B)</p> Signup and view all the answers

What is the purpose of the internal vent condenser?

<p>To condense the steam and remove gases (D)</p> Signup and view all the answers

What is the function of the steam flow gauge?

<p>To measure the steam flow (D)</p> Signup and view all the answers

What is the purpose of the safety valve?

<p>To prevent overpressure (B)</p> Signup and view all the answers

How does a bubbling tray deaerator work?

<p>By forcing steam up through perforated panels (A)</p> Signup and view all the answers

What is the function of the level control valve?

<p>To control the water level (A)</p> Signup and view all the answers

What happens to dissolved gases in water as the temperature rises?

<p>Their solubility decreases (A)</p> Signup and view all the answers

Why are deaerators used in boiler feedwater systems?

<p>To remove dissolved gases from the water (D)</p> Signup and view all the answers

What is the purpose of scrubbing the water with steam in a deaerator?

<p>To help sweep away released gases (B)</p> Signup and view all the answers

What is the effect of increasing temperature on the solubility of dissolved gases in water?

<p>It decreases the solubility (D)</p> Signup and view all the answers

What is the purpose of the trays in a tray-type deaerator?

<p>To increase the surface area of the water (D)</p> Signup and view all the answers

What is the difference between a tray-type and spray-type deaerator?

<p>The method of water-steam contact (B)</p> Signup and view all the answers

What is the purpose of the spray nozzles in a spray-type deaerator?

<p>To break up the water into small particles (C)</p> Signup and view all the answers

What is the result of not removing dissolved gases from boiler feedwater?

<p>Corrosion of the boiler (B)</p> Signup and view all the answers

MEDIUM What is the primary benefit of increasing the surface area of the water in a deaerator?

<p>To promote greater water-steam contact and improve degassing efficiency (B)</p> Signup and view all the answers

What is the role of turbulence in a deaerator?

<p>To ensure efficient mixing in support of gas scrubbing (B)</p> Signup and view all the answers

What happens to the oxygen and carbon dioxide in the deaerator?

<p>They are vented to the atmosphere (D)</p> Signup and view all the answers

What is the effect of residence time on a deaerator's efficiency?

<p>It increases the efficiency of the deaerator (D)</p> Signup and view all the answers

What is the purpose of the condenser section in a deaerator?

<p>To condense and vent the steam (A)</p> Signup and view all the answers

What is the function of the Level Control Valve?

<p>To control the water flow (D)</p> Signup and view all the answers

What is the purpose of heating the water in a deaerator?

<p>To reduce the solubility of dissolved gases (B)</p> Signup and view all the answers

Which of the following is a key difference between a tray-type and spray-type deaerator?

<p>The method of increasing the surface area of the water (C)</p> Signup and view all the answers

What is the purpose of the steam in a deaerator?

<p>To scrub the water and remove dissolved gases (B)</p> Signup and view all the answers

What is the difference between an internal vent condenser and an external vent condenser?

<p>One is mounted inside the deaerator vessel and the other is mounted outside (C)</p> Signup and view all the answers

What is the result of removing dissolved gases from boiler feedwater?

<p>Reduced corrosion in the boiler (C)</p> Signup and view all the answers

Why is it important to vent the released gases from the deaerator?

<p>To prevent the released gases from re-dissolving in the water (A)</p> Signup and view all the answers

What is the purpose of the combination deaerator?

<p>To combine the spray and tray principles (B)</p> Signup and view all the answers

What is the purpose of combining the steam flow with the water in a deaerator?

<p>To create turbulence and promote efficient mixing (B)</p> Signup and view all the answers

What is the effect of increasing the water temperature in a deaerator?

<p>It decreases the solubility of dissolved gases (D)</p> Signup and view all the answers

What is the purpose of the perforated panels in a bubbling tray deaerator?

<p>To force steam up through the water (C)</p> Signup and view all the answers

What is the purpose of the safety valve in a deaerator?

<p>To prevent overpressure in the deaerator (B)</p> Signup and view all the answers

What is the result of deaerating the water in a deaerator?

<p>The water becomes less prone to corrosion and scaling (D)</p> Signup and view all the answers

What is the primary factor that affects the solubility of dissolved gases in water?

<p>Temperature (B)</p> Signup and view all the answers

Which of the following operating parameters is not directly affected by the design of the deaerator?

<p>Temperature (A)</p> Signup and view all the answers

What is the primary benefit of using a combination deaerator?

<p>Flexibility in operation (D)</p> Signup and view all the answers

Which of the following is a disadvantage of the spray-type deaerator compared to the tray-type deaerator?

<p>Lower surface area (C)</p> Signup and view all the answers

What is the primary purpose of the scrubber in a deaerator?

<p>To remove dissolved gases (A)</p> Signup and view all the answers

What is the effect of increasing the residence time in a deaerator?

<p>Increased efficiency (A)</p> Signup and view all the answers

Which of the following is a characteristic of the tray-type deaerator?

<p>Increases the surface area of the water (B)</p> Signup and view all the answers

HARD What is the primary reason for venting the released gases from the deaerator?

<p>To prevent corrosion (A)</p> Signup and view all the answers

What is the primary function of the steam in the deaerator during the heating process?

<p>To increase the water temperature (D)</p> Signup and view all the answers

What is the purpose of the trays in a combination deaerator?

<p>To increase the surface area of the water (B)</p> Signup and view all the answers

What is the effect of increasing the residence time in a deaerator?

<p>It increases the deaeration efficiency (A)</p> Signup and view all the answers

What is the purpose of the internal vent condenser in a combination deaerator?

<p>To condense the steam and vent the gases (D)</p> Signup and view all the answers

What is the role of the overflow valve in a deaerator?

<p>To regulate the water flow (B)</p> Signup and view all the answers

What is the primary benefit of using a bubbling tray deaerator?

<p>It increases the deaeration efficiency (B)</p> Signup and view all the answers

What is the purpose of the thermometer in a deaerator?

<p>To measure the water temperature (D)</p> Signup and view all the answers

What is the effect of increasing the water temperature in a deaerator?

<p>It decreases the solubility of dissolved gases (B)</p> Signup and view all the answers

What is the purpose of the safety valve in a deaerator?

<p>To prevent overpressure in the deaerator (A)</p> Signup and view all the answers

What is the primary difference between an internal vent condenser and an external vent condenser?

<p>The location of the condenser (B)</p> Signup and view all the answers

Study Notes

Boiler Feedwater Systems and Deaerators

  • Dissolved gases, such as oxygen and carbon dioxide, have lower solubility in water as the water temperature rises.
  • Deaerators are used to remove dissolved gases from boiler feedwater to prevent corrosion in boilers.

Deaerator Operating Parameters

  • Temperature: an increase in temperature reduces the solubility of dissolved gases.
  • Turbulence: steam flow ensures efficient mixing in support of gas scrubbing.
  • Surface Area: the use of trays increases the surface area of the water, which improves the degassing efficiency.
  • Time: a deaerator's efficiency is a function of the residence time.

Deaerator Configurations

  • Tray Type: inlet water is directed into a steam chamber, where it heats up and then cascades down several trays to increase the surface area of the water.
  • Spray Type: inlet water is broken up into small particles with spray nozzles to promote water-steam contact.

Deaerator Components and Control Mechanisms

  • Steam Supply
  • Steam Flow Gauge
  • Level Control Valve
  • Relief Valve
  • Level Alarm Low and Low-Low
  • Pressure Gauge
  • Air Vent
  • Condensate Safety Valve
  • Thermometer
  • Vent

Deaerator Process

  • Inlet water is heated and scrubbed with steam to release dissolved gases.
  • Released gases and steam are vented from the deaerator.
  • Degassed water is stored in the deaerator and withdrawn continuously as needed by the boiler feedwater pump.

Tray-Type Deaerator

  • Water flow is broken up by trickling down over a series of trays.
  • Entering steam scrubs the water in the lower trays and heats the water in the upper tray section.
  • Released gases and remaining steam pass to the internal vent condenser, where most of the steam is condensed and the gases are vented to atmosphere.

Combination Deaerator

  • Water is first sprayed into the upper heating section of the deaerator.
  • Then, it trickles over a series of steam-swept trays.
  • Released gases and remaining steam pass through the incoming water spray on their way to the vent opening, causing most of the steam to condense.

Boiler Feedwater Systems and Deaerators

  • Dissolved gases, such as oxygen and carbon dioxide, have lower solubility in water as the water temperature rises.
  • Deaerators are used to remove dissolved gases from boiler feedwater to prevent corrosion in boilers.

Deaerator Operating Parameters

  • Temperature: an increase in temperature reduces the solubility of dissolved gases.
  • Turbulence: steam flow ensures efficient mixing in support of gas scrubbing.
  • Surface Area: the use of trays increases the surface area of the water, which improves the degassing efficiency.
  • Time: a deaerator's efficiency is a function of the residence time.

Deaerator Configurations

  • Tray Type: inlet water is directed into a steam chamber, where it heats up and then cascades down several trays to increase the surface area of the water.
  • Spray Type: inlet water is broken up into small particles with spray nozzles to promote water-steam contact.

Deaerator Components and Control Mechanisms

  • Steam Supply
  • Steam Flow Gauge
  • Level Control Valve
  • Relief Valve
  • Level Alarm Low and Low-Low
  • Pressure Gauge
  • Air Vent
  • Condensate Safety Valve
  • Thermometer
  • Vent

Deaerator Process

  • Inlet water is heated and scrubbed with steam to release dissolved gases.
  • Released gases and steam are vented from the deaerator.
  • Degassed water is stored in the deaerator and withdrawn continuously as needed by the boiler feedwater pump.

Tray-Type Deaerator

  • Water flow is broken up by trickling down over a series of trays.
  • Entering steam scrubs the water in the lower trays and heats the water in the upper tray section.
  • Released gases and remaining steam pass to the internal vent condenser, where most of the steam is condensed and the gases are vented to atmosphere.

Combination Deaerator

  • Water is first sprayed into the upper heating section of the deaerator.
  • Then, it trickles over a series of steam-swept trays.
  • Released gases and remaining steam pass through the incoming water spray on their way to the vent opening, causing most of the steam to condense.

Boiler Feedwater Systems and Deaerators

  • Dissolved gases, such as oxygen and carbon dioxide, have lower solubility in water as the water temperature rises.
  • Deaerators are used to remove dissolved gases from boiler feedwater to prevent corrosion in boilers.

Deaerator Operating Parameters

  • Temperature: an increase in temperature reduces the solubility of dissolved gases.
  • Turbulence: steam flow ensures efficient mixing in support of gas scrubbing.
  • Surface Area: the use of trays increases the surface area of the water, which improves the degassing efficiency.
  • Time: a deaerator's efficiency is a function of the residence time.

Deaerator Configurations

  • Tray Type: inlet water is directed into a steam chamber, where it heats up and then cascades down several trays to increase the surface area of the water.
  • Spray Type: inlet water is broken up into small particles with spray nozzles to promote water-steam contact.

Deaerator Components and Control Mechanisms

  • Steam Supply
  • Steam Flow Gauge
  • Level Control Valve
  • Relief Valve
  • Level Alarm Low and Low-Low
  • Pressure Gauge
  • Air Vent
  • Condensate Safety Valve
  • Thermometer
  • Vent

Deaerator Process

  • Inlet water is heated and scrubbed with steam to release dissolved gases.
  • Released gases and steam are vented from the deaerator.
  • Degassed water is stored in the deaerator and withdrawn continuously as needed by the boiler feedwater pump.

Tray-Type Deaerator

  • Water flow is broken up by trickling down over a series of trays.
  • Entering steam scrubs the water in the lower trays and heats the water in the upper tray section.
  • Released gases and remaining steam pass to the internal vent condenser, where most of the steam is condensed and the gases are vented to atmosphere.

Combination Deaerator

  • Water is first sprayed into the upper heating section of the deaerator.
  • Then, it trickles over a series of steam-swept trays.
  • Released gases and remaining steam pass through the incoming water spray on their way to the vent opening, causing most of the steam to condense.

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Learn about the importance of deaerators in boiler feedwater systems and how they prevent corrosion by removing dissolved gases from the water.

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