U.S. patent application number 14/930774 was filed with the patent office on 2017-05-04 for design of an air injection system at the level of the cylinder in a coke drum.
This patent application is currently assigned to Intevep, S.A.. The applicant listed for this patent is Intevep, S.A.. Invention is credited to Maria Isabel Specht, Gabriel Arcangel Vivas Chacon.
Application Number | 20170121607 14/930774 |
Document ID | / |
Family ID | 58634452 |
Filed Date | 2017-05-04 |
United States Patent
Application |
20170121607 |
Kind Code |
A1 |
Vivas Chacon; Gabriel Arcangel ;
et al. |
May 4, 2017 |
DESIGN OF AN AIR INJECTION SYSTEM AT THE LEVEL OF THE CYLINDER IN A
COKE DRUM
Abstract
A system for controlling thermal changes using air injection
including a coke drum having a cylindrical outer surface, a
material surrounding the cylinder defining an annular space between
the material and the cylindrical outer surface, and an air
injection system communicated with the annular space for
introducing air into the annular space. A method of operating the
system is also included.
Inventors: |
Vivas Chacon; Gabriel Arcangel;
(Los Teques, VE) ; Specht; Maria Isabel; (San
Antonio de Los Altos, VE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Intevep, S.A. |
Caracas |
|
VE |
|
|
Assignee: |
Intevep, S.A.
Caracas
VE
|
Family ID: |
58634452 |
Appl. No.: |
14/930774 |
Filed: |
November 3, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10B 3/02 20130101; C10B
55/00 20130101; C10B 41/00 20130101; C10B 47/30 20130101; C10B 1/04
20130101 |
International
Class: |
C10B 41/00 20060101
C10B041/00; C10B 3/02 20060101 C10B003/02; C10B 47/30 20060101
C10B047/30 |
Claims
1. A system for controlling thermal changes using air injection
comprising: a coke drum having a cylindrical outer surface, a
material surrounding the drum so as to define an annular space
between the material and the cylindrical outer surface, and an air
injection system communicated with the annular space for
introducing air into the annular space.
2. A system as in claim 1 wherein the material surrounds the drum
around the entire cylindrical outer surface.
3. A system as in claim 1 wherein the drum comprises a main body
defining the outer cylindrical surface and cone shaped bottom
connected to the main body.
4. A system as in claim 3 wherein a skirt is attached to a top of
the cone shaped bottom.
5. A system as in claim 1 wherein the air injection system is
communicated with the annular space by a toroid tube.
6. A system as in claim 5 wherein the toroid shaped tube further
comprises an inlet air intake.
7. A system as in claim 6 wherein the air injection system injects
air into the annular space through the toroid shaped tube.
8. A system as in claim 6 wherein air exits the annular space
through an outlet at the top of the annular space.
9. A system as in claim 1 wherein the material is thermal
insulation.
10. A system as in claim 1 wherein the material defines an outer
layer having a bottom, and wherein the bottom of the outer layer is
above the cone shaped bottom.
11. A system as in claim 1 wherein the material partially surrounds
the drum around cylindrical outer surface.
12. A method for controlling thermal changes using air injection
comprising the steps of, monitoring temperature inside a coke drum
having a cylindrical outer surface, a material surrounding the
cylindrical outer surface so as to define an annular space between
the material and the cylinder, and an air injection system
communicated with the annular space for introducing air into the
annular space, and, operating the air injection system using air
with temperature closer to temperature of items to be placed into
the drum than temperature of current contents of the drum, to feed
air through the annular space and prevent conditions that lead to
bulging of the coke drum.
13. A method as in claim 12 wherein the air is injected at a
temperature within 1000.degree. C. degrees of the temperature
inside of the drum.
14. A method as in claim 12 wherein the air is injected at a
temperature within 1000.degree. C. degrees of the temperature the
top of the drum.
15. A method as in claim 12 wherein the air is injected at a
temperature within 1000.degree. C. degrees of the temperature at
the bottom inside the drum.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to a system and a method for
controlling thermal changes in a coke drum.
[0002] Coke drums are thin-walled pressure vessels that operate
under severe cyclic heating and quenching conditions for coke
materials. Often bulging occurs when the temperature of the
contents of the drum are decreased from 420.degree. C. to
90.degree. C. Drum bulging can lead to leaks that in extreme cases
can result in fires. Coke drums are one of the most failure prone
components in refineries making them costly and dangerous.
[0003] Some try to address the bulging problem by incorporating
longitudinal welds during the fabrication of the coke drum, to
strengthen the areas prone to stresses and bulging. The problem
with this design is that it does not preclude the stresses that
lead to bulging. The method only pauses the bulging effect,
eventually the stresses weaken the structure enough that the
longitudinal welds do not help and bulging ensues. The need exists
for a way to address bulging issues permanently by decreasing the
stresses from mechanical and thermal effects.
SUMMARY OF THE INVENTION
[0004] According to the invention, a system and method are provided
to decrease the stresses on a coke drum during operation, which
stops the bulging effect.
[0005] The present invention features a system and method for
controlling coke drum bulging using air injection. The coke drum is
a hollow cylinder. As the contents of the drum cycle through high
and low temperatures, the drum exterior experiences extreme
stresses. The system utilizes an air injection system that injects
air with temperature closer to temperature of items to be placed
into the drum than temperature of current contents of the drum into
an annular space that is created by the outside of the coke drum
and a layer of insulation material. Air is injected into the
annular space at a temperature such that the changes in temperature
experienced by the drum are not as rapid.
[0006] The details of one or more embodiments of the invention are
set forth in the accompanying drawings and the description below.
Other features, objects, and advantages of the invention will be
apparent from the description and drawings, and from the
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 shows a cutaway view of a coke drum with air
injection system according to the invention.
DETAILED DESCRIPTION
[0008] According to the invention, a system and method are provided
to decrease the stresses on a coke drum during operation, which
stops the bulging effect.
[0009] The present invention features a system for controlling coke
drum bulging using air injection.
1. Referring generally to FIG. 1 the system comprises a coke drum
(2) which features a cylindrical main body (4) having an outer
cylindrical surface, a cone shaped bottom (6) and a skirt (12),
that can be attached to the junction of cone shaped bottom (6) and
cylindrical main body (4), as well as an air injector (20).
Cylindrical main body (4) is surrounded by a layer of thermal
insulation (8), having a top (24) and bottom (22), creating an
annular space (10) between the cylindrical main body (4) and the
layer of thermal insulation (8). A toroid tube (14), can be
communicated with the bottom (22) of annular space. Air injector
(20) is communicated with toroid tube (14), and toroid tube (14)
can be used as an air inlet device into annular space (10) for
uniform distribution of air. Air is injected into annular space
(10) by air injector (20) at a specified temperature, and this
slowly changes the temperature of cylindrical main body (4),
thereby allowing the temperature of cylindrical main body (4) to
change less rapidly during operational cycles, which prevents high
stresses and bulging of cylindrical main body (4).
[0010] An air outlet (26) from annular space (10) can be defined
near the top (24) of layer of thermal insulation (8). Air exiting
outlet (26) can be recycled back into the system encompassing the
invention or can be fed to other processes of a larger system.
Alternatively air exiting outlet (26) can be vented back as
exhaust. During the drum pre-heating and heating stages hot air can
come from various processes throughout a larger system, such as a
twin drum that could be operating on a schedule opposite coke drum
(2) , while during drum cooling stages, before and during quenching
stages, ambient air can be used as the colder air.
[0011] According to one embodiment of the invention the temperature
of the contents of the coke drum (2) can be monitored at the coke
drum inlet (30)by a temperature monitor (28), for example during
quenching and heating. The air being injected into annular space
(10) can be injected at a temperature such that cylindrical main
body (4) is heated closer to the expected temperature of the
incoming contents. This prevents cylindrical main body (4) from
experiencing rapid changes in temperature and high temperature
gradients during coke drum operational cycles which can promote the
bulging.
[0012] Particularly useful in retrofitting situations where a drum
has specific areas that are most prone to bulging, in another
embodiment of the invention, insulating material (8) does not
surround the entire cylindrical main body (4) but is only placed in
specific targeted areas creating a flow space between the
insulating material (8) and the outside surface of cylindrical main
body (4). The areas are selected based on where temperature changes
are fastest, in order to protect those areas.
[0013] The system of the invention can be used in new coke drums or
can be retrofitted to existing coke drums. Parts of the system can
be applied to existing coke drum systems on an as needed basis.
[0014] The system of the invention can be used to adjust the
temperature of the drum to be closer to the temperature of a
material about to be added to the drum, and can be used to keep
temperature changes at that wall of the drum more controlled and
uniform. This helps avoid bulging of the drum as desired.
[0015] The present invention provides a novel and non-obvious
method for one or more embodiments of the present invention have
been described. Nevertheless, it will be understood that various
modifications may be made without departing from the spirit and
scope of the invention. For example, the exact placement of the
insulation material, the materials used and the shape of the coke
drum. Accordingly, other embodiments are within the scope of the
following claims.
* * * * *