midterms part 2 page 17-21 Flashcards
Provides rotational energy to the driven equipment.
DRIVER
example of driver
electric motors
connects Driver to the Driven equipment
connector
example of connector
-Couplings
-Belts
-Chains
-Gear boxes
it is the output
DRIVEN EQUIPMENT
example of driven equipment
-Fans
-Compressors
-Pump
also referred to as degradation mechanisms
Damage Mechanisms
is a general term referring to any cause of problems or failures within process equipment. These can range from corrosion, to cracking, to heat damage, and everything in between.
Damage Mechanisms
a specialized device engineered to regulate the flow of fluid in process piping
systems.
valve
There are two types by which valves can be operated:
-Manually
-Using Actuator
Valves are installed on equipment to perform the following functions:
- Starting/Stopping of fluid flow.
- Controlling the amount of fluid flow.
- Controlling the direction of fluid flow and preventing backflow.
- Regulating the downstream system or process pressure.
The different types of actuators
pneumatic, hydraulic, electric, etc.
feature a convex disc-shaped plug that is raised and lowered through a
rising stem within the spherical interior of the globe-shaped body.
Globe valves
utilize a disc-like gate that moves vertically, operated by a screwed stem
and handwheel.
Gate valves
The fluid’s path through the valve is distinctively _______..
causing the flow direction to
change twice, leading to a higher pressure drop.
S-shaped
utilize a ball-shaped obstructor held in place between two cup-shaped
seals.
ball valves
Commonly used for system shut-off or isolation, these valves are tailored to function either fully open or fully closed.
By simply rotating the globe 90 degrees using a lever,
the valve can be closed or opened.
ball valves
ensures both precise flow control and a tight seal when fully closed.
spherical design of the plug
A valve commonly used for throttling and on-off service
butterfly valve
The body of this type of valve is relatively small compared to other valves, and therefore it occupies much less space in a pipeline.
butterfly valve
designed to respond automatically to sudden increases in pressure.
relief valves
opens at a predetermined pressure.
relief valves
a disc is held in place by a spring that will not open until system
pressure exceeds its operating limits. Tremendous pressures can be generated in
process units.
relief valves
is a device that adjusts how fluids move in an industrial system.
control valve
control valve has two parts..
-valve body
-valve actuator
which directs the fluid
valve body
which powers the movement
valve actuator
chemical industry uses _____ for storage
tanks, drums, bins, and spheres
used more than any other pipe fittings.
It Provides flexibility to change the
pipe direction.
elbow
made from various metals and materials,
is designed for safe chemical
transport.
industrial piping
the component in a pipeline that reduces the pipe size from a larger to a
smaller bore (inner diameter).
reducer
is storage vessel commonly found in the food and chemical sectors. it can
hold either solid materials like grains or powders
bin tank
to ensure a consistent material supply, aiming to avoid situations where it runs out of material or where unwanted air enters the delivery
lines.
bin tank
designed to move gases
or liquids
pumps
can only move gas.
compressor
designed to transfer fluids by increasing their kinetic energy, which can subsequently be converted into pressure energy as the fluid navigates through the system.
pumps
directly elevate the pressure energy of gases by compressing them within a confined space.
compressors
works by increasing the kinetic energy of fluid
pumps
increases pressure energy
compressors
can only compress gases
compressors
works on both gases and liquids
pumps
works by transporting both fluids and gases
pumps
transports
only gases.
compressors
increases the energy of a fluid that is incompressible
pump
increases the energy of the fluid that is compressible.
compressor
designed without storage for it works by sucking fluids in from one end and
forcing it out from the other end.
pump
Dynamic pumps are classified into different types such as
-Centrifugal
-Vertical centrifugal
-Horizontal centrifugal
-Submersible
-Fire hydrant systems.
They impart velocity to the fluid using a rotating impeller, which is then converted to pressure energy.
dynamic pumps
moves a fluid by repeatedly enclosing a fixed volume and moving it mechanically through the system. The pumping action is cyclic and can be driven by pistons, screws, gears, rollers, diaphragms or vanes.
A positive displacement (PD) pump
Positive displacement pumps are classified into different types such as
-diaphragm
-gear
-peristaltic
-lobe
-piston pumps
Can handle sludges, slurries, and
other fluids with suspended
solids. They can be air or
mechanically operated
Diaphragm
has Smooth flow, sensitive to solids
gear
has Minimal contamination, shear-sensitive
Peristaltic
Provides a smooth, non-pulsating flow. It’s also relatively gentle, making it suitable for shear-sensitive fluids.
lobe
Capable of very high pressures.
Depending on the design, can
handle a variety of fluids.
piston
different types of pumps
-dynamic pumps
-positive displacement pumps
types of compressor
-positive displacement
-dynamic
operate by accelerating the gas and converting the energy to
pressure.
dynamic compressors
operate by trapping a specific
amount of gas and forcing it into a smaller volume.
They are classified as rotary or
reciprocating.
Positive displacement compressors
This type of compressor can be either centrifugal or axial.
dynamic compressors
They are classified as rotary or
reciprocating.
Positive displacement compressors
the transfer of energy from one molecule to another by direct contact.
This transfer occurs when molecules hit against each other, like a game of pool where
one moving ball strikes another, causing the second to move.
conduction
is the movement of heat by a fluid such as water or air.
convection
The fluid (liquid or
gas) moves from one location to another, transferring heat along with it. This movement
of a mass of heated water or air is called
current
the transfer of heat by electromagnetic waves. Note that, unlike conduction
or convection, heat transfer by radiation does not need any matter to help with the
transfer.
radiation
which states that energy (in the form of heat and work)
can neither be created nor destroyed. It can only be transferred to another
system or converted to one form or another
First Law of Thermodynamics
referred to as the Law of
Conservation of Energy,
First Law of Thermodynamics
In First Law of Thermodynamics…
In heat exchangers, this statement is translated by the heat balance equation written as
(Heat In) + (Generation of Heat) = (Heat Out) + (Accumulation of Heat)
it introduces the concept of
entropy, the degree of disorderliness and randomness of a system. The entropy
of the universe is constantly increasing and can never decrease. It tells us the
direction of the flow of energy between two interacting systems in which the
highest entropy is generated.
Second Law of Thermodynamics
it is always transferred from a body with higher
temperatures to lower temperatures which is the natural tendency of all systems.
heat
devices that transfer heat between fluids without mixing or
blending them.
Heat exchangers
it is a substance, as a liquid or gas, that is capable of flowing and that changes its
shape at a steady rate when acted upon by a force tending to change its shape.
fluid
the fluid that heats /cools the process.
Working fluid
the fluid that is heated or cooled down
Process fluid
what is the hot fluid to the cold fluid sequence?
1.From the hot fluid to the adjacent surface of the wall by convection.
- Through the wall surface side by conduction.
- From the wall to the cold fluid by convection.
the heat transferring process can
be…
-gas-to-gas
-liquid-to-gas,
-liquid-to-liquid
The main characteristics by which heat exchangers can be categorized include:
a) Flow configuration
b) Construction method
c) Heat transfer mechanism
also referred to as the flow arrangement
flow configuration
refers to the direction of movement of the fluids within the heat exchanger in relation to
each other.
flow configuration
There are four principal flow configurations employed by heat exchangers
-Co-current flow
-Countercurrent flow
-Crossflow
- Hybrid flow
also referred to as parallel flow heat exchangers
Co-current flow heat exchangers
are heat exchanging devices in which the fluids move parallel to and in the same direction as each other.
Co-current flow heat exchangers
it typically results in lower efficiencies than a counter flow
arrangement, it also allows for the greatest thermal uniformity across the walls of the
heat exchanger.
Co-current flow heat exchangers
also known as counter flow heat exchangers
Countercurrent flow heat exchangers
are designed such that the fluids move antiparallel (i.e., parallel but in opposite directions) to each other within the heat exchanger
Countercurrent flow heat exchangers
typically exhibits the highest
efficiencies as it allows for the greatest amount of heat transference between fluids and,
consequently, the greatest change in temperature
Countercurrent flow heat exchangers
fluids flow perpendicularly to one another
crossflow heat exchangers
exhibit some combination of the characteristics of the
previously mentioned flow configurations.
Hybrid flow heat exchangers
The CONSTRUCTION
characteristics by which these devices can be classified include
-Recuperative vs. regenerative
* Direct vs. indirect
* Static vs. dynamic
* Types of components and materials employed
can be classified as recuperative heat exchangers and regenerative
heat exchangers.
heat exchangers
commonly called recuperators
recuperative heat exchangers
each fluid
simultaneously flows through its own channel within the heat exchanger.
recuperative heat exchangers
also referred to as capacitive heat
exchangers or regenerators
regenerative heat exchangers
alternately allow warmer and cooler fluids to flow through
the same channel.
regenerative heat exchangers
employ either direct contact or indirect contact transfer
processes to exchange heat between fluids.
Recuperative heat exchangers
the fluids are not separated within the device and
heat transfers from one fluid to another through direct contact.
direct contact heat exchangers
two main types of regenerative heat exchangers
static heat exchangers and
dynamic heat exchangers
processes include tubular or plate heat exchangers
indirect contact transfer processes
the fluids remain separated from one
another by thermally conductive components, such as tubes or plates, throughout the
heat transfer process. The components first receive heat from the warmer fluid as it
flows through the heat exchanger, and then transfer the heat to the cooler fluid as it
flows through.
in indirect heat exchangers
include cooling
towers and steam injectors
direct contact transfer processes
also known as fixed bed regenerators
static regenerators
the heat exchanger
material and components remains stationary as fluids flow through the device.
static regenerators
the material and components move throughout the heat
transfer process.
dynamic regenerators
There are two types of heat transfer mechanisms employed by heat exchangers
-single-phase
-two-phase heat transfer.
the fluids do not undergo any phase change throughout the heat transfer process, meaning that both the warmer and cooler fluids
remain in the same state of matter at which they entered the heat exchanger.
single-phase heat exchangers
fluids do experience a phase
change during the heat transfer process. The phase change can occur in either or both of the fluids involved resulting in a change from a liquid to a gas or a gas to a liquid.
two-phase heat exchangers
require more complex design
two-phase heat transfer mechanism
types of two-phase heat exchangers examples
-boilers,
-condensers,
-evaporators.
common variants
employed throughout industry
Types of Heat Exchangers
-Shell and tube heat exchangers
- Double pipe heat exchangers
-Plate heat exchangers
-Condensers, evaporators, and boilers
constructed of a single tube or series of parallel tubes (i.e., tube bundle) enclosed within
a sealed, cylindrical pressure vessel (i.e., shell).
shell and tube heat exchangers
one pipe held concentrically
inside of a larger pipe
Double pipe heat exchangers
acts as the conductive barrier
inner pipe
where one fluid flows through this inner
pipe and another flows around it through the outer pipe,
it forms..______?
annulus shape
works via conduction, where the heat from one flow is
transferred through the inner pipe wall, which is made of a conductive material such as
steel or aluminum.
double pipe heat exchanger
often used in counterflow, where
its fluids move in opposite directions
double pipe heat exchanger
are constructed of several thin, corrugated plates bundled
together
Plate heat exchangers
The plates are
arranged in a ___________ pattern to maximize the thermal mixing between each
fluid.
a cold-hot-cold-hot
r. Each pair of plates creates a channel through which one fluid can flow, and the
pairs are stacked and attached—via __________________ such that a second
passage is created between pairs through which the other fluid can flow.
—via bolting, brazing, or welding
heat exchangers which employ a two-phase
heat transfer mechanism.
Boilers, condensers, and evaporators
are heat exchanging devices that take heated gas or vapor and cool it to
the point of condensation, changing the gas or vapor into a liquid.
condensers
the heat transfer process changes the fluids from liquid form to gas or vapor form.
evaporators and boilers
is a simple device used by industry to remove heat from water
cooling tower
transfers heat to cooler air as it passes through the internal components of the
tower.
hot water
a special type of heat exchanger
cooling tower
that allows water and air to
come in contact with each other to lower the temperature of the hot water
cooling tower
what is the purpose of a cooling tower?
to cool down water
that gets heated up
by industrial equipment
and processes
Most cooling towers work based on the principle of?
“evaporative cooling“
the process where warm water from an industrial process is pumped up to the top of the cooling tower where the water distribution system is
Evaporative cooling
a closed vessel inside which water is stored.
boiler
generally coal
fuel
burnt in a furnace and hot gasses are produced.
fuel
the hot gasses come in contact with water vessel where the heat of these hot gases
transfer to the water and consequently steam
is produced in
boiler
commonly called boilers
Steam generators
are used by industrial manufacturers to
produce steam
Steam generators
used to drive turbines and provide heat to process equipment
steam
classified as fire-tube or water-tube boilers.
Steam generators
typically designed for large industrial applications.
Water-tube boilers
reverse of the fire tube boiler
Water-tube boilers
used in smaller systems and processes.
Fire-tube boilers
there are numbers of tubes through which hot gases are passed and
water surrounds these tubes.
Fire-tube boilers
the water is heated inside tubes and hot gasses surround these
tubes
Water-tube boilers
a device used primarily to heat large quantities of
hydrocarbons. These systems are very expensive and complex and require a well-trained and dedicated staff.
fired heater or furnace
consist essentially of a battery of pipes or tubes that pass through a
firebox.
Fired heaters
The primary source of heat transfer is
radiant and convective
it occurs as energy passes through the tubes
conductive heat
transfer
is a device used to convert raw materials into useful products through
chemical reactions
reactor
These devices combine raw materials with catalyst, gases, pressure, or heat
reactor
The basic components of a reactor
-shell
-heating or cooling device
-two or more product inlet ports
-one outlet port.
may be used to blend the
materials together.
mixer
Several critical process variables associated with reactor operation
-temperature
-pressure
-concentration of reactants
-catalysts,
-time
designed to make chemical bonds, break chemical bonds, or make and break
chemical bonds, temperature is carefully controlled.
a chemical reactor
used to speed up the reaction.
catalyst
a chemical that can
increase or decrease a reaction rate without becoming part of the product.
A catalyst
Chemical reactions are classified as
-Based on Heat Transfer
-Based on Reaction Type
Based on Heat Transfer types
-Exothermic
-Endothermic
Based on Reaction Type
- Replacement
- Neutralization
_______ reactions produce heat
Exothermic
_________ reactions require heat
endothermic
an exothermic reaction.
combustion
are those that absorb heat from the surroundings.
endothermic
absorb heat from the surroundings
Endothermic
In this type of reaction, one element displaces or replaces another element in a
compound.
Replacement (Single Displacement) Reaction:
When zinc reacts with copper sulfate, zinc displaces the copper, forming zinc sulfate
and releasing copper metal.
Zn + CuSO4 → ZnSO4 + Cu
its an example of…
Replacement (Single Displacement) Reaction
This type of reaction occurs when an acid and a base react to form water and a
salt. It’s called “neutralization” because the acid’s properties are neutralized by
the base, and vice versa.
Neutralization Reaction
this is an example of….
Hydrochloric acid reacting with sodium hydroxide produces water and sodium chloride.
HCl+NaOH→H2O+NaCl
Neutralization Reaction
is a series of stills placed one on top of another
distillation
a process that separates substances from a mixture by the various boiling
points of the substances.
distillation
The condensed
liquid is referred to as
distillate
the liquid that does not vaporize in a column is
residue
usually accomplished with a pump-around loop or a mixer
mixing
Heat balance on the tower is maintained by a device known as a
reboiler
are usually shell-and-tube heat exchangers or fired furnaces
Preheaters
one way of making such a separation, and it is perhaps the most frequently used method
Distillation
Distillation columns come in two basic designs
plate and packed.
take suction off the bottom of the tower.
reboiler
all four materials are liquids,
and the mixture is separated by allowing them to separate into layers (layer out) by
weight or density.
liquid-liquid extraction
is a process for separating
two materials in a mixture by introducing a third material that will dissolve one of the first
two materials but not the other.
extraction
One of the problems most frequently encountered in chemical process operations is that
of separating two materials from a mixture or a solution.
SEPARATORS
