Column Presentation

Refinery Column
Prepared By: Taifur Ahmed Tarek

(Maintenance & Utility Department)
Principle of Column
Columns are vertical separator with internal trays or
packing to allow greater separation performance
Relative volatility
is a measure of
differences in
volatility between
two components.
It indicates how
easy or difficult a
separation will be.
Necessity of Column in Refinery
 Separation Process : Separation is performed in a distillation
column/tower. Furnace besides distillation column heats and
vaporizes the NGC mixture. The vapor and liquid mixture is
then fed into the bottom section of the column. The feed
section is the hottest point in the distillation column.
Components that are still liquid at this elevated temperature
become the column’s bottom product. Components that are in
vapor form rise up the column through a series of distillation
stages. The temperature decreases as the vapors rise through
the column and the components condense.
Necessity of Column in Refinery (Cont.)
 Purification Process: Once NGC are separated the resulting
products are ready for purification which is principally sulfur
removal.
Stripping is a physical separation process where one or more
components are removed from a liquid stream by a vapor stream.
Stripping is usually carried out in either a packed or trayed column.
Trayed column consist of a vertical with liquid flowing in the top
and out the bottom. The vapor phase enters in the bottom of the
column and exits out of the top. Inside of the column are trays . The
purpose of these trays is to increase the amount of contact area
between the liquid and vapor phases.
Types of Distillation Column
 Batch Column :
In Batch operation, the feed to the column is introduced batch-wise.
That is, the column is charged with a batch and then the distillation
process is carried out. When the desired task is achieved, a next batch
of feed is introduced.
 Continuous Column :
Continuous columns process a continuous feed stream. No
interruptions occur unless there is a problem with the column or
surrounding process units. They are capable of handling high
throughputs and are the most common of the two types.
Types of Continuous Column
 The nature of the feed that they are processing,
􀀹Binary column -feed contains only two components
􀀹multi-component column -feed contains more than two components
 The number of product streams they have
􀀹multi-product column -column has more than two product streams
 Where the extra feed exits when it is used to help with the separation,
􀀹extractive distillation -where the extra feed appears in the bottom product stream
􀀹azeotropic distillation -where the extra feed appears at the top product stream
 The type of column internals
􀀹Tray column -where trays of various designs are used to hold up the liquid to
provide better contact between vapor and liquid, hence better separation
􀀹Packed column -where instead of trays, 'packings' are used to enhance contact
between vapor and liquid
Trayed Columns
A Tray consist of
1)Overflow or
weir
2)Down comer
3) Tray Deck
Tray Component
Tray Component Tray Assembly

Packed Column
 Packing's are passive devices that are designed to increase the
interfacial area for vapor-liquid contact. These shaped pieces are
supposed to impart good vapor-liquid contact when a particular type
is placed together in number,without causing excessive pressure-drop
across a packed section. This is important because a high pressure
drop would mean that more energy is required to drive the vapor up
the distillation column.
Column Internal
 Sieve Tray : Sieve trays are simply metal plates with holes in them. Vapor
passes straight upward through the liquid on the plate. The arrangement, number
and size of the holes are design parameters.
 Valve Tray : In valve trays, perforations are covered by lift able caps. Vapor
flows lifts the caps, thus self creating a flow area for the passage of vapor. The
lifting cap directs the vapor to flow horizontally into the liquid, thus providing
better mixing than is possible in sieve trays.
 Bubble cap Tray :A bubble cap tray has riser or chimney fitted over each
hole, and a cap that covers the riser. The cap is mounted so that there is a space
between riser and cap to allow the passage of vapor.
Because of the efficiency, wide operating range, ease of maintenance and cost
factors, sieve and valve trays have replaced the once highly thought of bubble cap
trays in many applications.
Different Tray Types
Comparison of common Tray Types
Tray Efficiency
Distillation trays in a fractionator operate between 10 and 90
percent efficiency.
Tray Efficiency : Compare the vapor temperature leaving a tray to
the liquid temperature leaving the tray.
Poor Tray Efficiency is caused by:
•Flooding Tray and down comer fill. Inadequately sized flow path
for liquid.
•Weeping Leakage caused by low gas rate.
List of PRL Column at a Glance
 C-100 (Fractionation Column- Tray Column)
 C-101 (Stripping Column –Packed Column)
 C-201(Stripper Column- Tray Column)
 C-301 (Stabilizer Column-Tray Column)
 C-302(De-Ethenizer Column –Tray Column)
C-100 Column Internal
C-100 MVG Tray
In design , Required number of valves -246

Actual number of valves -250
MVG Tray Features
Sulzer’s MVG trays provide higher capacity compared to standard sieve
or valve trays, while providing higher efficiency and lower pressure drop
per theoretical stage. The MVG tray deck offers better turndown capability
than a sieve tray, i.e. up to 3:1.
Advantages of MVG Tray
 Mini V-Grid trays use smaller valves than the conventional SVG valve
 Provide up to 20% higher capacity compared to standard sieve or valve
trays
 Deliver higher efficiency and lower pressure drop per theoretical stage
 MVG trays are well proven in various industrial applications ranging from
low to high pressure distillation
Column-100 Item List
Item Qty unit Description Material
1 32 Pcs 32*1 pass MVG Tray 316/L-14404
2 1 Pcs SKI chimney Tray below tray #12 316/L-14404
4 15 Pcs 15*1 pass MVG Tray 316/L-14404

C-100 Item List (Continue)
Item Qty unit Description Material
8 1 Pcs General Attachment SA-516 Gr 70N
9 1 Pcs LTE Elbow for Nozzle N8 316/L-14404

C-201 Stripper (Arrangement of internal)
Column-201(Tray Arrangemant)
Arrangement of Tray (#8- Arrangement of Tray

Arrangement of Tray (#1- (#16-29) (Here 170 MDV
7) (Here 89 MDV valve) 15) (Here 170 MDV
valve) valve)
Column-201 Internal Bundle Tray photograph
Column troubleshooting using Gamma Ray Scanning
Analyzing gamma ray scanning a number of common malfunction in trayed

or packed column can be determined.
 Mechanical Problem:
 Displaced or damaged trays, demister pads and packing
 Corrosion resulting in partial tray damage
 Missing, collapsed or buckled trays or man ways
 Out-of-place liquid or vapor distributors
 Level control problems on chimney trays or base liquid level
 Process Related Problem :
 Foaming on trays or in re boilers, condensers and accumulators
 Mal distribution of vapour and liquid in packing
 Liquid hold-up due to plugging and fouling
 Superheated or sub cooled feed or reflux
Distinguishing features of the Gamma Ray Technology
 Capable of non-disruptive and non-invasive investigation.
 Scans are performed on-line, hence normal operation of the column is not
disrupted. They are carried out completely external to the process.
 Full length scanning capabilities.
 No preparation of columns (for additional scaffolding or staging) and components
dismantling is required. Only requires access from readily available platforms or
walkways.
 Insulation or lagging need not be removed.
 Performs non-contact measurement, therefore, is not affected by high temperature,
high pressure, corrosiveness etc.
 Utilizes small amount of “sealed radioactive source” with in-built radiological
safety features to comply with national and international legislative requirements.
 Applicable to all column sizes.
 Uses computer-aided data acquisition, retrieval and analysis system enabling fast,
accurate and reliable results.
Principle of measurement (GR Technology)
Gamma Ray Absorption scan in a Trayed column
• The mass absorption

coefficient, m is constant
for a given gamma-ray
energy and material
composition.
• The increase in material
density will reduce the
radiation signal or
conversely a decrease in
material density will
result to an increase in the
level of radiation intensity
transmitted to the
detector.
Maintenance of Column (Chemical Cleaning)
The chemical cleaning procedures for column during a major shut down
consist typically of two types of cleanings: the liquid phase and vapor
phase chemical cleaning .
 Steam Chemical Cleaning (SCC) or Decontamination is performed to
remove the volatile organic components and inorganic solids such as iron
sulfide producing volatile toxic gasses. The objective is to reduce the
required steam-out time before entering the equipment. The SCC or
decontamination phase in intended to prepare the equipment to a gas free
state, which is minimum required for safe entry into the equipment for
inspection and/or other activities.
 Chemical Cleaning in liquid phase is performed when SCC alone is not
sufficient to remove the fouling or deposits. Depending on the type of
contamination and the objective of the cleaning, the liquid phase chemical
cleaning could contain one or more steps. These are Degreasing,
Degassing , Acid Cleaning.
Thanks to ALL

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Refinery Column

Prepared By: Taifur Ahmed Tarek

􀀹multi-product column -column has more than two product streams

Tray Component Tray Assembly

In design , Required number of valves -246

1 32 Pcs 32*1 pass MVG Tray 316/L-14404

2 1 Pcs SKI chimney Tray below tray #12 316/L-14404

3 1 Pcs SKI chimney Tray below tray #27 316/L-14404

4 15 Pcs 15*1 pass MVG Tray 316/L-14404

5 1 Pcs SKI chimney Tray below tray #43 316/L-14404

6 1 Pcs SKI chimney Tray below tray #9 316/L-14404

7 1 Pcs SKI chimney Tray below tray #14 316/L-14404

8 1 Pcs General Attachment SA-516 Gr 70N

9 1 Pcs LTE Elbow for Nozzle N8 316/L-14404

10 1 Pcs LTE Elbow for Nozzle N1 316/L-14404

11 1 Pcs LTE Elbow for Nozzle N12 316/L-14404

12 1 Pcs LTE Elbow for Nozzle N13 316/L-14404

Arrangement of Tray (#8- Arrangement of Tray

Analyzing gamma ray scanning a number of common malfunction in trayed

Gamma Ray Absorption scan in a Trayed column

• The mass absorption

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