Chemical Engineering CRE LAb assignment lab

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University of Gujrat,
Faculty of Engineering
Department of Chemical Engineering
Program: BSc chemical Engineering
Course code CHE-
Course Title CRE LAB
Semester/Year 5th
Semester
Instructor Engr. Fahad Nisar
ASSIGNMENT No. 01
Assignment Title Types of Reactors
Student Name SYED MUHAMMAD USMAN SHAH
Student ID 16103123-022
Submission Date 05-Dec-2018
Marks

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Ideal reactors have three ideal flow or contacting patterns.
Batch Flow Reactor:
In Batch Flow reactor there is uniform composition everywhere in the reactor but of course the
composition changes with time. In the batch reactor or BR the reactants are initially charged
into container, are well mixed, and are left to react for a certain period. The resultant mixture is
then discharge. This is an unsteady-state operation where composition changes with time
however at any instant the composition throughout the reactor is uniform.
Semi batch(semi flow) reactors operate much like batch reactors in that they take place in a
single stirred tank with similar equipment. However, they are modified to allow reactant
addition and/or product removal in time.
Plug Flow Reactor:
In this type of Reactor fluid passes through the reactor with no mixing of earlier and later
entering fluid and with no overtaking it is as if the fluid moved in single moves in single file
through the reactor. The first of two ideal steady state flow reactors is variously known as the
plug flow slug flow piston flow ideal tabular and unmixed flow reactor. We refer it as the plug
flow reactor or PFR and to this pattern of flow as plug flow It is characterized by the fact that
the flow of fluid through the reactor is orderly with no element of fluid overtaking or mixing
with any other element ahead or behind. Actually there may be lateral mixing of fluid in a plug
flow. It is characterized by the fact that the flow of fluid through the reactor is orderly with no
element of fluid overtaking or mixing with any other element ahead or behind. Actually there
may be lateral mixing of any fluid in a plug flow reactor, however there must be no mixing or
diffusion along the
flow path. The
necessary and
sufficient condition
or plug flow is for the

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residence time in the reactor to be the same for all elements of fluid. The plug flow reactor
model (PFR, sometimes called continuous tubular reactor, CTR, or piston flow reactors) is
a model used to describe chemical reactions in continuous, flowing systems of cylindrical
geometry. The PFR model is used to predict the behavior of chemical reactors of such design,
so that key reactor variables, such as the dimensions of the reactor, can be estimated.
Mixed Flow Reactor:
The feed is uniformly mixed in this reactor and same composition everywhere within the reactor
at the exit. The other ideal state flow reactor is called mixed flow, the backmix reactor, the ideal
stirred tank reactor and the C(meaning C-star) CSTR, or the CFSTR (constant flow stirred tank
reactor) and as its names suggest, it is a reactor in which the contents are well stirred and
uniform throughout. Thus, the exit stream from this reactor has the same composition as the
fluid within the reactor. We refer to this type of flow as mixed flow, and the corresponding
reactor the mixed flow reactor, or MFR.
These three ideals are relatively easy to treat. In addition
one or usually represents the best way of contacting the reactants--- no matter what the
operation. For these reasons we often try to design ideal reactors so that their flows approach
these ideals.