Process Technology Equipment exam 3
thin material transfers heat better, fins create turbulence
Fins are added to tubes because
Convection
Fluids when warmer molecules move toward coller moecules.
Tube-and-shell pressure rating
Fouling resistance is determined by all of the following except the
forced, induced
Mechanical draft towers use fans to force air in (_______________ draft) or pull air out (_______________ draft).
water distribution header, hot water inlet to cooling tower
A pipe that evenly disperses hot water over the fill of a cooling tower is
increasing fluid velocity, lowering the temperature, adding inhibitors
A process technician can reduce fouling in a heat exchanger by
Kettle reboiler
A shell-and-tube heat exchanger with a vapor disengaging cavity, used to supply heat for separation of lighter and heavier componenets in a distillation system and to maintain heat balance.
parallel flow
A term applied to fluid flow that is equally distributed to multiple pieces of equipment. Example is heat exchanger
cross flow
A term used to describe flow in a heat exchanger where shell-side flow vertically crosses the horizontal tube flow is
counter flow
A term used to describe flow in a heat exchanger where tube-side flow and shell-side flow go in opposite directions is
parallel flow
A term used to describe flow in a heat exchanger where tube-side flow and shell-side flow go in the same directions is
multi-pass, u-tube, floating head
A type of heat exchanger that channels the tube-side flow across the tube bundle more than once is
kettle
A type of heat exchanger that uses a tubular bundle to heat and flash a liquid in an over-sized shell with a vapor disengaging cavity is a
forced, slows-down, 20% efficiency decrease
Air moves through a (forced draft or induced draft) at a higher rate. What happens to the flow rate at the discharge point?
radiant
All of the following are examples of heat transfer found in a heat exchanger except
Basin heaters
Are designed to keep cooling system water from freezing during the winter months.
Longitudinal baffles
Are used inside the shell to split or divide the flow, increase velocity, and provide superior heat transfer capabilities.
10%, 20%
Sensible heat transfer accounts for _______________ to _______________ of the cooling effect in a cooling tower
section
Shell and tube nomenclature includes all of the following except
Air intake louvers
Slats located at the bottom or sides of a cooling tower to direct airflow
thermal shock
Sudden temperature changes that result in the rapid expansion or contraction of metal is
Basin
Concrete storage compartment located at the bottom of the cooling tower.
Turbulent flow
random movement or mixing in swirls and eddies of a fluid.
Laminar flow
streamline flow that is more or less unbroken; layers of liquid flowing in a parallel path.
plenum
the open area directly under the fan.
static film
A layer of fluid that tends to adhere to the walls of a heat exchanger is referred to as
impingement
A baffle that is designed to deflect high velocity fluids inside a heat exchanger are called
fouling
A common term used to describe the internal buildup on the surface area of a heat exchanger that results in restricted flow is
it produces air flow; mechanical or natural, the air flows in relation to the downward flow of water; cross, or counter current
A cooling tower is classified by how
Channel head
A device mounted on the inlet side of a shell and tube heat exchanger that is used to channel flow in a multipass heat exchanger is called the
splash bar
A device used in a cooling tower to break up and redirect the flow of falling water is a
air-cooled heat exchanger
A fin fan is an example of a(n)
double pipe
A hairpin heat exchanger is an example of
drift eliminators
Devices used in a cooling tower to keep water from blowing out are called
Drift eliminators
Devices used in a cooling tower to keep water from blowing out.
80%, 90%
Evaporative cooling accounts for _______________ to _______________ of the cooling effect in a tower.
Baffles
Evenly spaced partitions in a shell-and tube heat exchanger that support the tubes, prevent vibration, control fluid velocity and direction, increase turbulent flow, and reduce hot spots.
Conduction
Heat energy is transferred through solid objects such as tubes, heads, baffles, plates, fins, and shell.
electromagnetic wave intensity
Heat exchanger effectiveness is linked to all of the following except
Plate and frame
Heat exchangers are easy to clean and have high heat transfer coefficients.
plate and packed
Heat exchangers can be found in all of the following categories except
sensible heat
Heat that can be measured or sensed is referred to as
power plants
Hyperbolic towers are primarily designed for service in what industry?
Fouling
Internal buildup on the surface area of a heat exchanger that results in a restriction is referred to as
Segmental baffles
Often used in horizontal shell-and-tube heat exchangers.
shell inlet valve #3- steam
On a simple shell and tube heat exchanger, a process technician would close which of the following valves first?
tube outlet valve #2- process fluid 325 F
On a simple shell and tube heat exchanger, a process technician would turn the device into a bomb if he closed which of the following valves first.
Fill
Plastic or wood surfaces that direct airflow and provide for contact of water and air in a cooling tower
Wet-bulb temperature
The air temperature as measured by a thermometer that takes into account the relative humidity.
Dry-bulb temperature
The air temperature as measured without taking relative humidity into account.
differential pressure, Δ P (delta P)
The difference between inlet and outlet pressures is commonly referred to as
personnel
The efficiency of a tower is tied to all of the following factors except
u-tube
The heat exchanger that is designed to take the highest flow rates and largest temperature differences is
relative humidity
The measure of how much water the air has absorbed at a given temperature is the
relative humidity
The measurement of how much water the air has absorbed at a given temperature is
wind velocity
The rate of air flow in a natural draft cooling tower depends primarily on
scale
The result of dissolved solids adhering to internal surfaces of equipment in the form of deposits is
Cell
The smallest subdivision of a cooling tower that can function as an independent unit. Some cooling tower systems have multiple.
Approach to tower
The temperature difference between the water leaving a cooling tower and the wet-bulb temperature of the air entering the tower.
corrosion
This results when electrochemical reactions occur between metal surfaces and surrounding hot water that results in the gradual wearing away of metal.
Horizontal baffles
Used in vapor-phase or all-liquid-phase operations.
louvers
Vents located on the side of a cooling tower are called
The air temperature as measured by a thermometer that takes into account the relative humidity
WBT or wet-bulb temperature is the
Laminar and Turbulent
What are the two major classifications of fluid flow?
vertical baffles, impingement baffle,longitudinal baffles
What is the name of the metal plates located inside a shell and tube heat exchanger that are designed to increase turbulent flow and reduce hotspots?
Natural, mechanical
_______________ draft cooling towers use natural forces to bring air into a cooling tower while _______________ draft towers use fans to induce or force air into a tower.
Tub head
a floating head heat exchanger is firmly attached to the tube sheet.
Impingement baffles
are used to protect tubing from direct fluid impact.
Cooling tower
box-shaped collection of multi-layered wooden slats and louvers that direct air flow and breaks up water as it falls from the top of the tower or water distribution header, internal design of the tower that ensures good air and water contact
shell-an-tube
heat exchanger can be used to heat and cool a substance
Hairpin
heat exchangers are relatively easy to clean and install.
Sensible heat
heat that can be measured or sensed by a change in temperature.
