U.S. patent application number 11/817565 was filed with the patent office on 2009-02-19 for apparatus for combusting collected diesel exhaust material from aftertreatment devices and method.
This patent application is currently assigned to Donaldson Company, Inc.. Invention is credited to John T. Herman, Mary Joanne Lorenzen, Wayne M. Wagner.
Application Number | 20090044523 11/817565 |
Document ID | / |
Family ID | 36169182 |
Filed Date | 2009-02-19 |
United States Patent
Application |
20090044523 |
Kind Code |
A1 |
Wagner; Wayne M. ; et
al. |
February 19, 2009 |
APPARATUS FOR COMBUSTING COLLECTED DIESEL EXHAUST MATERIAL FROM
AFTERTREATMENT DEVICES AND METHOD
Abstract
The present disclosure relates to an apparatus for combusting
soot from a diesel engine exhaust aftertreatment device. The
apparatus includes a cabinet having a housing, a heating element
positioned within the housing of the cabinet, and a mounting
arrangement for securing the diesel engine exhaust aftertreatment
device above the heating element. The apparatus also includes an
ash collection container mounted beneath a floor of the housing for
collecting ash that falls from the diesel engine exhaust
aftertreatment device during heating.
Inventors: |
Wagner; Wayne M.; (Apple
Valley, MN) ; Lorenzen; Mary Joanne; (Chanhassen,
MN) ; Herman; John T.; (Rhinelander, WI) |
Correspondence
Address: |
MERCHANT & GOULD PC
P.O. BOX 2903
MINNEAPOLIS
MN
55402-0903
US
|
Assignee: |
Donaldson Company, Inc.
Minneapolis
MN
|
Family ID: |
36169182 |
Appl. No.: |
11/817565 |
Filed: |
January 18, 2006 |
PCT Filed: |
January 18, 2006 |
PCT NO: |
PCT/US06/01850 |
371 Date: |
June 16, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60658612 |
Mar 4, 2005 |
|
|
|
Current U.S.
Class: |
60/303 |
Current CPC
Class: |
B01D 2279/30 20130101;
F01N 3/023 20130101; F01N 3/027 20130101; F01N 3/0237 20130101;
B01D 46/48 20130101; F01N 3/0233 20130101; B01D 41/04 20130101 |
Class at
Publication: |
60/303 |
International
Class: |
F01N 3/10 20060101
F01N003/10 |
Claims
1. An apparatus for combusting soot from a diesel engine exhaust
aftertreatment device, the apparatus comprising: a cabinet having a
housing; a heating element positioned within the housing of the
cabinet; a mounting arrangement for securing the diesel engine
exhaust aftertreatment device above the heating element; and an ash
collection container mounted beneath a floor of the housing for
collecting ash that falls from the diesel engine exhaust
aftertreatment device during heating.
2. The apparatus of claim 1, further comprising a pulse generator
for directing pulses of air to a location beneath the heating
element.
3. The apparatus of claim 2, wherein the pulse generator includes a
nozzle positioned between the heating element and the ash
collection container that directs the pulse of air downwardly
toward the ash collection container.
4. The apparatus of claim 1, further comprising a porous heat
reflector positioned beneath the heating element at a location
between the heating element and the ash collection container.
5. The apparatus of claim 4, further comprising a pulse generator
for directing pulses of air to a location beneath the heating
element, the pulse generator including a nozzle positioned between
the heat reflector and the ash collection container that directs
the pulse of air downwardly toward the ash collection
container.
6. The apparatus of claim 1, further comprising a vent for venting
products of combustion from the housing.
7. The apparatus of claim 6, further comprising a blower for
facilitating venting the products of combustion through the
vent.
8. The apparatus of claim 1, wherein the housing includes a door
for inserting the aftertreatment device into the housing and for
removing the aftertreatment device from the housing, and wherein
the apparatus includes a sensor for detecting if the door is
opened.
9. The apparatus of claim 8, further comprising a controller that
prevents the heating element from being heated if the door is
open.
10. The apparatus of claim 1, wherein the housing includes a door
for inserting the aftertreatment device into the housing and for
removing the aftertreatment device from the housing, and wherein
the apparatus includes and electronic latch that prevents the door
from being opened when the heating element is hot.
11. The apparatus of claim 10, further comprising a stop button for
deactivating the heating element and for deactivating the
electronic latch.
12. The apparatus of claim 1, further comprising a cabinet
temperature sensor for sensing a temperature within the housing,
wherein the heating element is deactivated if a temperature in the
housing exceeds a predetermined temperature value.
13. The apparatus of claim 1, further comprising a heating element
temperature sensor for sensing a temperature of the heating
element.
14. The apparatus of claim 13, wherein the apparatus deactivates
the heating element of the heating element exceeds a predetermined
temperature.
15. The apparatus of claim 13, further comprising a temperature
gage for displaying the temperature of the heating element.
16. The apparatus of claim 1, further comprising further comprising
a fan for facilitating venting the products of combustion through
the vent.
17. The apparatus of claim 1, further comprising an aftertreatment
device sensor for sensing whether an aftertreatment device is
present above the heating element.
18. The apparatus of claim 1, further comprising a slide lock
arrangement for securing the aftertreatment device above the
heating element.
19. The apparatus of claim 18, further comprising a platform
positioned within the housing, wherein the slide lock arrangement
includes a plurality of slide bars mounted to the platform, the
slide bars being slideable between first positions in which the
slide bars are adapted to engage a lower flange of the
aftertreatment device to secure the aftertreatment device in place
above the heating element, and second positions where the slide
bars are spaced from the lower flange.
20. The apparatus of claim 1, further comprising an insulating
component for insulating the aftertreatment device, the insulating
component including an insulating layer positioned between inner an
outer metal layers.
21. The apparatus of claim 20, wherein the insulating component
includes first and second half-cylinders.
22. A method for cleaning a diesel engine exhaust aftertreatment
device comprising: positioning the aftertreatment device over a
heating element; heating the aftertreatment device with the heating
element to burn soot on the aftertreatment device; providing pulses
of air that move upwardly through the aftertreatment device during
heating.
23. The method of claim 22, further comprising cooling the
aftertreatment device by turning off the heating element and
increasing the amount of air that flows upwardly through the
aftertreatment device.
24. The method of claim 22, wherein no air is pulsed through the
aftertreatment device during an initial warming period.
Description
[0001] This application is being filed on 18 Jan. 2006 as a PCT
International Patent application in the name of Donaldson Company,
Inc., a U.S. national corporation, applicant for the designation of
all countries except the US, and Wayne M. Wagner, Mary Joanne
Lorenzen, and John T. Herman, all citizens of the U.S., applicants
for the designation of the US only, and claims priority to U.S.
Provisional Application Ser. No. 60/658,612, filed Mar. 4,
2005.
TECHNICAL FIELD
[0002] The present invention relates generally to devices and
methods for servicing/cleaning diesel particulate filters or other
aftertreatment devices.
BACKGROUND
[0003] To reduce air pollution, engine exhaust emissions standards
have become increasingly more stringent. Aftertreatment devices
have been developed to satisfy these increasingly stringent
standards. For example, catalytic converters have been used to
reduce the concentration of pollutant gases (e.g., hydrocarbons,
carbon monoxide, nitric oxide, etc.) exhausted by engines. With
respect to diesel engines, diesel particulate filters have been
used to reduce the concentration of particulate matter (e.g., soot)
in the exhaust stream. U.S. Pat. No. 4,851,015, which is hereby
incorporated by reference, discloses an example diesel particulate
filter. Other example types of aftertreatment devices include lean
NOx catalyst devices, selective catalytic reduction (SCR) catalyst
devices, lean NOx traps, or other device for removing for removing
pollutants from engine exhaust streams.
[0004] At times, it is required to service aftertreatment devices.
To facilitate servicing, aftertreatment devices are often clamped
into an exhaust system as modules or separate units. For example,
clamps can be provided at flange interfaces located opposite
adjacent opposite ends of the aftertreatment devices. By removing
the end clamps, a given aftertreatment device can be removed from
its corresponding exhaust system for servicing.
[0005] In use, aftertreatment devices occasionally become
overloaded with soot, ash or other materials present in or
generated from engine exhaust. As aftertreatment devices become
overloaded, the devices cause undesirable backpressure in their
corresponding exhaust systems. When an aftertreatment device
becomes plugged to the point where excessive backpressure is a
concern, it is recommended to remove the device from its
corresponding exhaust system for servicing. To service a device
such as a diesel particulate filter, it is known to manually move a
focused stream of pressurized air back and forth across the outlet
side of the filter to loosen soot/ash that has collected on the
filter. For example, a compressed air gun (e.g., 50-100 psi) can be
used as a source of pressurized air. Simultaneously, an industrial
vacuum device is coupled to the inlet side of the filter. The
vacuum device is typically equipped with a high-efficiency
particulate air filter or ultra-low penetration air filter for
collecting the soot/ash that is blown from the filter by the
pressurized air. Total time for cleaning the filter depends on the
size of the filter, but is typically 30-50 minutes. However, the
small volume of compressed air typically provided from a compressed
air nozzle can often diffuse rapidly into the porous core of the
aftertreatment device thereby limiting effectiveness.
[0006] Diesel particulate filters can also be cleaned by using a
heating process to combust material captured on the filters. It is
known to use ovens for heating the diesel particulate filter. When
heating filters in an oven, filters have been known to crack
because the combustion is uncontrolled.
[0007] What is needed is an improved device/method for servicing
overloaded diesel particulate filters or other exhaust
aftertreatment devices.
SUMMARY
[0008] Certain aspects of the present disclosure relate to devices
and methods for efficiently and effectively combusting diesel
exhaust material present on diesel particulate filters or other
aftertreatment devices.
[0009] Examples representative of a variety of inventive aspects
are set forth in the description that follows. The inventive
aspects relate to individual features as well as combinations of
features. It is to be understood that both the forgoing general
description and the following detailed description merely provide
examples of how the inventive aspects may be put into practice, and
are not intended to limit the broad spirit and scope of the
inventive aspects.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a front view of an aftertreatment device
regeneration cleaner having features that are examples of inventive
aspects in accordance with the principles of the present
disclosure;
[0011] FIG. 2 is a side view of the cleaner of FIG. 1;
[0012] FIG. 3 is a perspective view of a vent and hood assembly of
the cleaner of FIG. 1;
[0013] FIG. 4 is a perspective view of a heating element and ash
collection container of the cleaner of FIG. 1;
[0014] FIG. 5 is a cross-sectional view taken along section line
5-5 of FIG. 4;
[0015] FIG. 6 is a perspective view of a base assembly of the
cleaner of FIG. 1;
[0016] FIG. 7 is an end view of the base assembly of FIG. 6;
[0017] FIG. 8 shows an insulation layer for insulating an
aftertreatment device during the heat cleaning process;
[0018] FIG. 9 is a schematic diagram of a control system for an
aftertreatment device regeneration cleaner having features that are
examples of inventive aspects in accordance with the principles of
the present disclosure;
[0019] FIG. 10 is a perspective view of an aftertreatment device
cleaner including the control system of FIG. 9; and
[0020] FIG. 11 is a transverse cross-sectional view of a
aftertreatment device insulating component shown at FIG. 10.
DETAILED DESCRIPTION
[0021] In the following detailed description, references are made
to the accompanying drawings that depict various embodiments which
are examples of how certain inventive aspects may be practiced. It
is to be understood that other embodiments may be utilized, and
structural and functional changes may be made without departing
from the broad scope of the inventive aspects.
[0022] The present disclosure relates to methods and systems for
efficiently and effectively cleaning diesel particulate filters
(DPF) or other exhaust aftertreatment devices. In one embodiment, a
cleaner includes a cabinet in which a heating element is
positioned. A compressed air outlet is provided beneath the heating
element. An ash collection container is mounted beneath the
compressed air outlet. A hood is provided for venting the products
of combustion from the cabinet. A blower or fan can be used to
force air into the cabinet for facilitating venting the products of
combustion through the hood. In use, a diesel particulate filter or
other aftertreatment device is mounted over the heating element and
the heating element is heated to start the combustion process. To
promote controlled combustion, pulses of air from the compressed
air outlet are directed into the region beneath the heating
element. The pulses move through the diesel particulate filter or
other aftertreatment device to enhance the combustion process. Air
nozzles used in generating the pulses can be aimed directly at the
diesel particulate filter being serviced or away from the diesel
particulate filter being serviced.
[0023] Throughout the remainder of the specification, cleaning
devices and methods are described primarily with respect to
cleaning diesel particulate filters. However, it will be
appreciated that the same devices and methods can be used to clean
other types of engine exhaust aftertreatment devices as well. Other
example aftertreatment devices that may require servicing include
catalytic converters, lean NOx catalyst devices, selective
catalytic reduction (SCR) catalyst devices, lean NOx traps, or
other devices for removing for removing pollutants from the exhaust
stream. The methods and cleaners can also be used to clean other
types of filters/treatment devices, and are not limited exclusively
to engine exhaust aftertreatment devices.
[0024] Diesel particulate filter substrates can have a variety of
known configurations. An exemplary configuration includes a
monolith ceramic substrate having a "honey-comb" configuration of
plugged passages as described in U.S. Pat. No. 4,851,015 that is
hereby incorporated by reference in its entirety. This type of
filter can be referred to as a wall-flow trap or filter. Common
materials used for wall-flow filters include silicon carbide and
cordierite. Wire mesh, corrugated metal foil and other flow-through
type filter configurations can also be used. In certain
embodiments, the filter substrate can include a catalyst. Exemplary
catalysts include precious metals such as platinum, palladium and
rhodium, and other types of components such as base metals or
zeolites.
[0025] As described herein, aftertreatment devices are described as
having inlet sides or faces and outlet sides or faces. The inlet
side or face of an aftertreatment device is the side that faces the
incoming flow of exhaust when installed in an exhaust system. The
inlet side can be referred to as the "dirty" side since it is the
side at which material filtered from the exhaust stream collects.
The outlet side or face of an aftertreatment device is the side
that faces away from the incoming flow of exhaust when installed in
an exhaust system. The outlet side can be referred to as the
"clean" side.
[0026] FIGS. 1 and 2 illustrate a cleaner 20 having features that
are examples of inventive aspects in accordance with the principles
of the present disclosure. The cleaner 20 includes a cabinet 21
having a rectangular housing 22 supported on legs 33 that elevate
the housing 22 above the ground. The legs 33 and a bottom wall 24
of the housing 22 cooperate to form a base assembly 25 (see FIG. 6
and 7) of the cabinet 21. The front of the cabinet 21 includes a
door 40 that can be opened to provide access to the interior of the
housing 22. An ash collection container 42 is mounted under the
housing 22 for collecting ash that drops from the DPF's as the
DPF's are cleaned. A vent stack 44 is mounted at the top of the
housing 22 for venting the products of combustion from the housing
22.
[0027] Referring to FIG. 3, the vent stack 44 is in fluid
communication with a fume and heat containment chamber 23 within
the interior of the housing 22. The vent stack 44 is part of an
assembly including a hood 46. The hood 46 is mounted beneath the
vent stack 42 within the chamber 23.
[0028] Referring to FIGS. 4 and 5, a heating element 50 (e.g., an
electric heating element (e.g., a coil, grid or other structure) or
other heating structure) is mounted in the chamber 23 adjacent the
bottom wall 24 of the housing 22. A heat reflector 52 (e.g., a
porous ceramic disc/plate) is mounted beneath the heating element
50. Preferably, the reflector 52 is sufficiently porous to readily
allow air and ash to pass therethrough. In one embodiment, the
reflector 52 includes 5-25 pores per inch and has a thickness in
the range of 0.5-2 inches. The reflector 52 prevents radiant heat
loss into the ash container since air flow through the reflector 52
carries heat from the reflector upwardly to the diesel particulate
filter being serviced.
[0029] The heating element 50 and the reflector 52 are mounted
within a cylindrical first pipe section 100 having flanged upper
and lower ends. The flanged upper end allows an aftertreatment
device to be clamped in place (e.g., with v-band clamp 102) over
the heating element 50. The lower flanged end of the first pipe
section 100 is clamped to the upper flanged end of a second pipe
section 104 (e.g., with v-band clamp 106). The second pipe section
104 includes an enlarged diameter portion 108 connected to a
reduced diameter portion 110 by a conical diameter transition
portion 112. The second pipe section 104 is secured (e.g., welded
or fastened) to a rim 114 secured to the bottom wall 24 of the
cabinet 21. The reduced diameter portion 110 of the second pipe
section 104 projects downwardly below the bottom wall 24 and has a
flanged lower end.
[0030] The ash collection container 42 is clamped (e.g., with
v-band clamp 116) to the lower flanged end of the second pipe
section 104. The ash collection container 42 includes a main bin 43
having an open top end covered by a lid 45. A pipe section 47 is
mounted at the center of the lid 45. The pipe section 47 extends
though the lid 45 and has a flanged upper end that can be clamped
to the lower flanged end of the second pipe section 104. The lid 45
is removable from the bin 43 to allow ash to be emptied from the
bin 43.
[0031] A compressed air outlet 45 (e.g., a nozzle, hose, pipe, of
other structure) is positioned between the reflector 52 and the
container 42. For example, in FIG. 5, the outlet 45 is shown
connected to a compressed air line 122 that extends through an
opening 120 in the second pipe section 104. In the depicted
embodiment, the outlet 45 is configured to direct air in a downward
direction toward the container 42. In other embodiments, the outlet
may direct air upwardly toward the heating element or laterally
toward the side wall of the second pipe section 104.
[0032] It is preferred of the outlet 45 to be in fluid
communication with a source of compressed air 124 via the line 122.
A controller 126 controls the amount of air provided to the outlet
45. The flow can be controlled/metered to control the rate of
combustion at the aftertreatment device being serviced. In one
embodiment, the controller interfaces with a solenoid 128 that
opens and closes to provide pulses of air to the outlet 45. In one
embodiment, the source of compressed air has a pressure of at least
60 pounds per square inch (psi), or in the range of 60-100 psi, or
preferably about 90 psi. In another embodiment, flow rates
preferably in the range of 0.5-2.0 standard cubic feet per minute
(SCFM) are provided beneath the heating element during
regeneration. In still another embodiment, pulses having durations
in the range of 0.25-1 s, a pulse frequency of about 2-15 or 2-8
pulses per minute, and a flow rate in the range of 0.5-2.5 SCFM or
0.75-1.25 SCFM are provided beneath the heating element. It will be
appreciated that the above numerical information is provided for
illustration purposes only, and is not intended to limit the broad
inventive aspects of the present disclosure.
[0033] The pulses of air provide a number of functions. For
example, the air pulses impinge on the aftertreatment device
causing soot and ash packed on the device to be dislodged and to
fall into the container 42. The upward flow of air also carries and
distributes heat evenly through the aftertreatment device. By
controlling the air flow rate, the amount of oxygen supplied to the
aftertreatment device can also be controlled to control the core
temperature and combustion rate. In a preferred embodiment, the
high pressure air pulse can penetrate soot built-up on the diesel
particulate filter.
[0034] A blower 70 or fan is also mounted in the housing 22. A wall
52 (see FIG. 4) separates the blower 50 from the chamber 23. A hose
54 provides fluid communication between the blower 50 and the
interior of the main chamber. The blower 70 forces air into the
main chamber to facilitate venting the products of combustion from
the chamber.
[0035] In use of the system, the front door 40 of the cabinet is
opened to provide access to the chamber 23. With the door open 40,
a diesel particulate filter (DPF) can be mounted (e.g., clamped or
otherwise secured) on top of the heating element. Preferably, the
DPF is mounted with the inlet side facing downwardly and the outlet
side facing upwardly. Once the DPF is in place, the door 40 is
closed and the heating element is activated to heat the core of the
DPF to a temperature suitable for combusting ash on the DPF (e.g.,
900-1500 F). During an initial warm-up period (e.g., about 20
minutes), the heating element is activated. During this warm up
period, it is preferred to not provide air pulses to the system so
that more uniform radiant heating is provided across the entire
face of the core being serviced. Uniform heating prevents
preferential air flow paths from developing in the DPF that may
interfere with the ability to uniformly regenerate the entire DPF.
After the warm-up period, the air outlet 45 begins to direct pulses
of air downwardly into the container 42 (e.g., at a pulse rate of
0.5 seconds on and 15 seconds off). The pulses of air reflect off
the container 42 and migrate upwardly through the heat reflector
52, the heating element 50 and the DPF mounted on the heating
element 50. The pulses of air assist in providing uniform
combustion temperatures across the entire volume of the DPF while
maintaining a controlled combustion. The pulses of air also assist
is dislodging ash from the DPF during the combustion process. The
ash falls downwardly from the DPF through the heating element 50
and the heat reflector 52 and is collected in the container 42. The
container 42 is preferably periodically disconnected from the
cabinet to be emptied.
[0036] After the combustion process has been completed (e.g., about
3-5 hours), the heating element 50 turned off and the air flow is
increased during the cool-down. In one embodiment, the flow rate is
increased to at least 1.5 times the regeneration air flow rate. For
example, the pulse rate can be increased to 0.5 second on and 4-10
s or 7.5 to 10 seconds off). The cool-down period can often extend
for 2-3 hours. After the heating element and cabinet interior cool
to a predetermined temperature (e.g., 140 F), the front door 40 can
be opened to remove the clean DPF. Thereafter, another DPF can be
mounted on the heating element 50 and the process can be
repeated.
[0037] During heating, if the heating element fails (e.g., a
heating controller does not modulate), the solenoid fails (e.g.,
sticks open or closed), or the cabinet temperature exceeds a
predetermined temperature, the system can be programmed to abort
the regeneration cycle.
[0038] To make the process more efficient, the DPF, the pipe
sections 100, 104 and the ash container 42 can be covered with
insulating layers (e.g., heat shields, blankets, sheaths, etc.) For
example, FIG. 8 schematically shows an insulation sheath/blanket
300 wrapped around the DPF and the pipe sections 100,104.
[0039] To improve cleaning, the combustion type cleaner disclosed
herein can be used in combination with a pulse cleaner of the type
disclosed at U.S. patent application Ser. No. not yet assigned,
having attorney docket number 758.1913USU1, entitled APPARATUS FOR
CLEANING EXHAUST AFTERTREATMENT DEVICES AND METHODS, filed on a
date concurrent herewith, which is hereby incorporated by reference
in its entirety. For example, after soot has been combusted from an
aftertreatment device with the heat cleaner of the present
disclosure, the aftertreatment device can then be placed in a pulse
cleaner to remove any residual ash.
[0040] FIG. 9 schematically shows an example control system for a
heat cleaner 320 in accordance with the principles of the present
disclosure. The heat cleaner 320 includes a cabinet 321 housing a
platform/table 323 for mounting a DPF, a heating element 350
mounted at a central opening of the table 323, a reflector 352
mounted below the heating element 350, an ash collection container
342 positioned below the reflector 352, and a compressed air outlet
345 for providing pulses of air that move through the DPF during
heating. The control system includes a main controller 326 that
interfaces with the various control components of the heater. The
controller 326 can include a microprocessor, memory, output drivers
and an analog to digital converter and other components
conventionally found in a controller. The memory can be used to
store software/firmware for use controlling a visual display (e.g.,
at a front of the cabinet) and for the overall control of the
module.
[0041] Referring to still to FIG. 9, the control system includes a
front control panel 400 having a visual display and also having
buttons for controlling operation of the heat cleaner 320. The
visual display includes a temperature gage 402 that shows the
temperature of the heating element 350. The visual display also
includes a light 402 that is illuminated during heating, a light
404 that is illuminated during cool-down, and a light 406 that
illuminates when a cleaning operation has been completed. The front
control panel 400 further includes a start button 408 that an
operator can depress to start a heating operation, and an emergency
stop bottom 410 that an operator can depress to stop a heating
operation at any time. A plurality of wires can be used to
electrically connect the components of the front panel 400 to the
controller 326.
[0042] The controller interfaces with a temperature sensor 405
(e.g., a thermocouple or thermometer) provided at the heating
element 350 to access temperature readings corresponding to the
temperature of the heating element 350. The controller 326 uses the
temperature readings to control the temperature gage 402. If the
temperature of the heating element 350 exceeds a predetermined
limit, the controller 326 can terminate heating operations by
disconnecting the heating element 350 from its power supply 412
(e.g., via power switch 414).
[0043] The controller 326 further interfaces with an electronic
latch 416 (e.g., a solenoid of other structure), a door sensor 418
(e.g., a push switch or other structure), a fan 420, an
aftertreatment device sensor 422 (e.g., a proximity sensor or other
device for detecting the presence of an aftertreatment device above
the heating element) and a cabinet temperature sensor 224 (e.g., a
thermometer, temperature switch or other structure for providing
feedback regarding temperature). The electronic latch 416 prevents
the cabinet door from being opened during heating operations. If it
is necessary to open the cabinet door during heating operations,
the emergency stop button 410 can be pressed to stop heating
operations and override the latch 416. The door sensor 418 senses
whether the cabinet door is opened or closed. The controller 326
will not begin a heating operation unless the cabinet door is
closed. The fan 420 provides air for exhausting/ventilating the
cabinet 321. The sensor 422 senses whether a DPF is in position
over the heating element 350. If the sensor 422 does not detect the
presence of a DPF, the controller will not allow a heating
operation to take place. The controller also will terminate heating
operations if the cabinet temperature exceeds a predetermined limit
as indicated by the cabinet temperature sensor 424.
[0044] The controller 326 also interfaces with a solenoid 426 and
an air pressure sensor 428. The solenoid 426 receives compressed
air from a source of compressed air 430, and is used by the
controller 326 to control the pulses (e.g., duration and timing) of
air provided to the compressed air outlet 345. The pressure sensor
428 reads whether sufficient pressure is being provided to the
solenoid. If sufficient pressure is not present, the controller
will either terminate heating operations if heating operations are
ongoing, or will prevent heating operations from being started.
[0045] FIG. 10 is a perspective view of a heat cleaner 320
including the control system of FIG. 9. The cleaner 320 includes
cabinet 321, DPF mounting table 323, heating element 350 and ash
collection container 342. The DPF mounting table 323 has a central
opening at which the heating element is positioned. A DPF retaining
arrangement is provided at the top of the table 323. The retaining
arrangement includes three sets of slide locks/bars (only two sets
are visible) secured to the table 323 by fasteners (e.g., bolts).
Each set of slide bars includes an upper bar 370 and a lower bar
371. The sets of slide bars 370 are spaced at about 120 degree
increments about the heating element 350. The upper slide bars 370
have elongated holes 373 for receiving fasteners 377. By loosening
the fasteners, the upper bars 370 can be slid back away from the
heating element 350 along the top sides of the bars 371 to allow a
DPF 375 to be placed on top of the heating element 350. Once the
DPF 375 is in place, the upper slide bars 370 can be slid toward
the DPF to position where the bars 370 overlap the lower flange of
the DPF 375. The slide bars 370 can then be tightened down with the
fasteners 377 such that the bars 370 firmly clamp the DPF 375 in
place against the top side of the heating element 350.
[0046] Referring still to FIG. 10, the system also includes an
insulating sleeve 500 mounted about the DPF 375 to retain heat
therein. The sleeve includes two half-cylinders 502 that are held
together by mechanical latches 503, hooks or other structures. The
half-cylinders 502 include an insulating material 507 (e.g.,
fiberglass) positioned between inner and outer layers 504, 506 of
metal (see FIG. 11). By unhooking the latches 503, the
half-cylinders 502 can be separated from one another and placed
about the DPF. 375. The latches 503 can then be re-attached to hold
the sleeve 500 about the DPF 375.
[0047] Referring again to FIG. 10, the heat cleaner 320 includes a
rear control box 600 in which the controller 326 is positioned.
Wires 603, 604 connect the controller respectively to the solenoid
426 and the pressure sensor 428. The solenoid 426 and the pressure
sensor 428 are mounted to the floor of the cabinet 321. The source
of compressed air connects to the solenoid 426 through the floor of
the cabinet 321. A hose 607 carries compressed air from the
pressure sensor 428 to the compressed air outlet 345.
[0048] As shown at FIG. 10, the front control panel 400 is
positioned at the front of the cabinet 321. A conduit 605 is used
to carry wires that interconnect the front panel 400 to the
controller 326. The door latch 416 and the door sensor 418 are also
positioned adjacent the front of the cabinet 321. Wires 611, 613
respectively connect the door latch 416 and the door sensor 418 to
the controller 326. The cabinet temperature sensor 424 is mounted
adjacent the top of the cabinet 321 and is connected to the
controller 326 by wire 615. Fans 420 and an aftertreatment device
sensor 422 are mounted to a divider wall 617 that separates the
cabinet 321 into a DPF cleaning chamber and a control chamber. The
control box 600, the solenoid 428 and the pressure switch 428 are
positioned within the control chamber. FIG. 10 also shows a wire
621 for providing power to the heating element 350, and a wire for
623 for allowing the controller 326 to take readings from the
temperature sensor 405.
[0049] It will be appreciated that the same types of heating and
cooling cycles/processes described with respect to the embodiment
of FIG. 5 can also be used in combination with the heat cleaner of
FIG. 10.
[0050] The above specification provides examples of how certain
inventive aspects may be put into practice. It will be appreciated
that the inventive aspects can be practiced in other ways than
those specifically shown and described herein without departing
from the spirit and scope of the inventive aspects.
* * * * *