AU2018203111B2

AU2018203111B2 - Filter unit

Info

Publication number: AU2018203111B2
Application number: AU2018203111A
Authority: AU
Inventors: Greg Venticinque
Original assignee: Ventico Australia Pty Ltd
Current assignee: Ventico Australia Pty Ltd
Priority date: 2017-05-05
Filing date: 2018-05-04
Publication date: 2023-01-12
Anticipated expiration: 2038-05-04
Also published as: AU2018203111A1; CN110593992A

Abstract

H:\khilterove\NR~rtb\DC\KM~l695329_[Ldx-4/05/2018 ABSTRACT A filter unit including a enclosure with an inner and outer wall and a lid, fittings to allow coolant to circulate through the enclosure, between the inner and outer wall and through the lid, and a catalysed filter insert within the enclosure. C-4 LLL C4

Description

C-4

LLL

C4

FILTER UNIT

Field

[0001] This invention relates to a filter unit particularly but not exclusively for use with a diesel engine.

Background

[0002] A catalysed filter is used with a diesel engine to promote combustion of collected soot (carbon) within the filter. The main purpose of a catalyst in the filter is to facilitate passive regeneration of the filter by enabling the oxidation of diesel particulate matter under exhaust temperatures experienced during regular operation of the engine, typically in the 300-400°C range. In the absence of the catalyst, particulates can be oxidized at appreciable rates only at temperatures around 550-650°C which can occur only at full load conditions in the diesel engine.

[0003] The catalysed filter is generally constructed of a porous catalysed material inside a metal housing. The housing has an enlarged central section that accommodates the filter material and tapers down to pipe couplings used to connect the filter into an exhaust system of the vehicle.

[0004] If the catalysed filter needs to be changed, the exhaust system is dismantled at the couplings to allow the entire housing to be removed and replaced, which can be a time consuming exercise.

[0005] Due to such maintenance downtime, a catalysed filter is not generally considered ideal for use with underground mining vehicles, where a vehicle stoppage for an extended period of time is costly.

[0006] A catalysed filter is also not considered suitable for use in underground coal mining, for example, as the operating temperature of the catalysed filter is too high for the environmental conditions. Coal mining equipment needs to operate with external surface temperatures preferably below 150°C since coal dust can spontaneously ignite at temperatures of about 1600 to 170°C.

[00071 Due to maintenance downtime concerns and the risk of spontaneous ignition in such an environment, paper filters are generally used instead of catalysed filters. Paper filters can be easily replaced and disposed of however the useful lifetime of a paper filter is relatively short and cumulative maintenance downtime and filter replacement costs can be expensive.

Summary

[0008] In one aspect, there is provided a filter unit including an enclosure comprising an inlet for receiving exhaust gases into the enclosure and an outlet to exhaust the exhaust gasses from the enclosure, and a catalysed filter insert located within the enclosure along a flow path of the exhaust gasses between the inlet and the outlet and adapted to filter said exhaust gasses. The enclosure further comprises an inner and outer wall and a lid, and fittings to allow coolant to circulate through the enclosure, between the inner and outer wall and through the lid. The lid is configurable between a removed configuration, in which the lid is removed to allow the filter insert to be removed from within the enclosure, and a closed configuration, in which the lid prevents removal of the filter insert from within the enclosure.

[0009] In one embodiment, the lid has a first and a second skin whereby coolant can circulate between the first and the second skin of the lid.

[0010] In one embodiment, the filter insert includes catalysed filter material inside a cylindrical casing.

[0011] In one embodiment, the filter insert includes a handle at an end of the casing to allow the insert to be gripped and lifted clear of the enclosure.

[0012] In one embodiment, a thermal separation gap is provided between the filter insert and the inner wall of the enclosure.

[00131 In another aspect, there is provided a vehicle including an engine and the filter unit, as described above, mounted in the vehicle to filter exhaust from the engine.

[00141 In one embodiment, the vehicle includes a turbocharger connected between the engine and the filter unit arranged such that the engine exhaust passes through the turbocharger before being delivered to the filter unit.

[0015] In one embodiment, the turbocharger is mounted inside an explosion proof box.

[00161 In one embodiment, the fittings connect the filter unit into a coolant circuit of the vehicle.

[00171 In another aspect, there is provided an exhaust treatment assembly including the filter unit, as described above, mounted to a scrubber.

[00181 In one embodiment, a minimum water level is maintained in the scrubber and a downpipe takes filtered exhaust from the filter unit down below the minimum water level so that the filtered exhaust passes through water before exiting the scrubber through an exhaust pipe.

[0019] In another aspect, there is provided a filter insert for the filter unit described above, including a casing around a catalysed material and a handle to lift the insert in and out of the enclosure.

[0020] In one embodiment, the filter insert includes a flange at a downstream end of the insert to support the insert at a base of the enclosure.

[0021] In one embodiment, the flange projects outwardly of a side wall of the casing so that the side wall of the casing is spaced from the enclosure to define a thermal separation gap between the insert and the enclosure.

Brief Description of the Invention

[0022] The invention is described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

[00231 Figure 1 is a perspective view of an insert;

[0024] Figure 2 is a perspective sectioned view of a portion of the insert material;

[00251 Figure 3 is a diagrammatic side view of a filter unit and scrubber of an exhaust treatment assembly;

[0026] Figure 4 is a rear view of the filter unit and scrubber;

[00271 Figure 5 is a top perspective view of an enclosure of the filter unit;

[0028] Figure 6 is a bottom perspective view of the enclosure;

[0029] Figure 7 is a bottom perspective view of a scrubber body;

[0030] Figure 8 is a top perspective view of the scrubber body;

[0031] Figure 9 is a schematic diagram illustrating flow paths through the exhaust treatment assembly;

[0032] Figure 10 is a schematic diagram illustrating the exhaust treatment assembly coupled to an engine;

[0033] Figure 11 is a schematic diagram illustrating coolant flow paths in the engine and assembly;

[0034] Figure 12 is a rear perspective view of an engine and exhaust treatment assembly fitted in an engine bay of a vehicle; and

[0035] Figure 13 is a front perspective view of the engine and exhaust treatment assembly.

Detailed Description

[0036] Figure 1 shows a filter insert 1 with a cylindrical casing 2, end flanges 3, 4 and a handle 5. A diesel oxidation catalyst material 6 is housed within the casing 2. Diesel exhaust is introduced into the material 6 at an engine tailpipe end 7 of the filter insert 1 and exits from a downstream end 8 of the filter insert 1.

[00371 Figure 2 illustrates the material 6 as being formed of an array of cells 9 with porous walls 10 and plugs 11 formed at the respective ends 7, 8 of the filter insert 1. Exhaust entering one of the cells 9 is indicated by an arrow 12. The exhaust flows through the porous walls 10 into adjoining cells as indicated by arrows 13 where particulates such as soot/carbon are captured. The filtered air then exits the cells 9 as indicated by arrows 14.

[00381 The catalyst in the filter insert 1 causes reduced temperature ignition of the soot in order to clear the filter insert 1 of particulates to thereby provide passive regeneration of the filter insert 1.

[00391 The material 6 is preferably a ceramic wall-flow monolith made of cordierite, however, any other suitable catalysed material can be used, as required.

[0040] Figure 3 is a cross-sectional view (taken along the line A-A of Figure 4) which shows an exhaust treatment assembly 20 which includes a filter unit 21 and a scrubber 22.

[0041] The filter unit 21 includes an enclosure 23 with an attachment plate 24 that connects the filter unit 21 to the scrubber 22. The enclosure 23 has an inner and outer wall , 26 and a double-skin lid 27. The lid 27 has fittings 28 that allow a coolant to cycle through the lid 27. Similar fittings 29 are provided in the outer wall 26 to provide access for coolant to enter and circulate between the inner and outer walls 25, 26.

[0042] The flange 3 supports the filter insert 1 in a base 30 of the enclosure 23. The flange 3 projects outwardly of a side wall 31 of the casing 2 so that a thermal separation gap 32 is defined between the insert 1 and the inner wall 25 of the enclosure 23.

[00431 An inlet 33 is provided at a top 34 of the enclosure 23 for receiving exhaust gases which are introduced into a void 35 above the insert 1. The exhaust gases pass through the filter insert 1 and exit from a funnel shaped outlet 36 extending from the base 30 of the enclosure which couples to a downpipe 37. The filtered exhaust from the downpipe 37 passes through the scrubber 22 and out an exhaust pipe 38.

[0044] Figure 4 is a rear side view of the filter unit 21 and scrubber 22, showing an overflow port 39 and an air bleed port 40 in the plate 24, a drainage port 41 and a low water port 42, which are used to control water levels in the scrubber.

[00451 Figure 5 and 6 further illustrate the relative positions of the overflow port 39 and air bleed port 40 on the plate 24 and the fittings 29 in the enclosure 23. The downpipe 37 is formed of a central conduit 43 and a manifold of smaller pipes 44.

[0046] Figure 7 and 8 show a scrubber body 45 with attachment feet 46 for connecting the scrubber 22 to a vehicle chassis (not shown).

[00471 Figure 9 illustrates flow paths through the exhaust treatment assembly 20. Exhaust enters the assembly through the inlet 33 of the filter unit 21, as indicated by arrows 50. The exhaust passes through the filter insert 1, out through the base 30 of the enclosure 23 and down the downpipe 37. The filtered exhaust then passes through water 51 in the scrubber 22 before exiting the scrubber 22 via the exhaust pipe 38, as indicated by arrow 52.

[00481 A minimum water level is maintained in the scrubber in order to accommodate the scrubber 22 being tilted at angles of, say, 15 degrees whilst still operating effectively. The minimum level is monitored by a low water test valve 53 connected to the low water port 42. Additional water is provided through a make up tank 54, which is coupled into the scrubber 22 via a strainer 55, a 3-way valve 56, primary and secondary floats 57, 58 and a water line 59. The port 39 is connected to the primary float 57 and the port 40 is connected to the secondary float 58. The 3-way valve 56 is used to shut off water and bleed air when a low water shut down test is used.

[0049] Figure 10 shows an air induction and exhaust gas path of an engine 60 fitted with a turbocharger 61. Air is received through a filter 62 and delivered to an air inlet 63 of the turbocharger 61. The air is compressed and sent to an air intake 64 of the engine 60, through an after-cooler 65. The engine exhaust from the turbocharger outlet 66 is transferred to the treatment assembly 20 through an engine tail pipe 67, where the exhaust gases pass through the filter unit 21 and scrubber 22 and exit through the exhaust pipe 38.

[0050] Figure 11 illustrates a coolant flow schematic 70, where a header tank 71 provides coolant through a coolant circuit 72 to the enclosure 23 of the filter unit 21, which allows the external temperature of filter unit 21 to remain at less than 150°C despite the internal operating temperature of the filter insert 1 being at around 300 to 400°C, which is the temperature required to activate the catalytic combustion of soot from the exhaust. The coolant circuit 72 is incorporated into the coolant system 73 of the engine 60 which flows through the radiator 74 to maintain low coolant temperatures through heat exchange with ambient air.

[0051] A separate coolant circuit 75 provides coolant to an explosion proof box 77 which houses the turbocharger 61 so that the external surface of the box 77 is maintained at a relatively low operating temperature. The construction detail of the explosion proof box would be readily known to a person skilled in the art. The turbocharger 61 may be further air-cooled by connecting air into the box in such a manner that air delivered to the turbocharger is firstly able to circulate within the box and around the turbocharger before entering the turbocharger for compression.

[0052] Figures 12 and 13 illustrate the positioning of the treatment assembly 20 in an engine bay 76 of a vehicle 80. The assembly 20 fits neatly into the engine bay 76 behind the radiator 74 and adjacent the engine 60 and the box 77 that houses the turbocharger 61.

[00531 As indicated above, the enclosure 23 is connected to a coolant system 73 of the vehicle 80 which, combined with the thermal separation gap 32 between the filter insert 1 and the enclosure 23, enables the external temperature of the filter unit 21 to remains relatively low. This allows the filter unit 21 to operate in, for example, an underground coal mine without risk of ignition of surrounding coal dust.

[0054] The lid 27 of the filter unit 21 can be easily removed and the handle 5 gripped and lifted in order to lift the filter insert 1 clear of the enclosure 23 for maintenance purposes and reconditioning of the filter material, if required. As such, wastage and cost associated with use and disposal of conventional paper filters can be avoided. Since the filter insert 1 is able to passively regenerate, maintenance is required only after extended operation hours, potentially greater than 10,000 hours, which is a considerably longer time than that associated with a paper filter based system. The downtime to swap in a replacement filter insert and close the lid 27 is also minimal so the vehicle need only be out of operation for a short time.

[0055] Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" or

"comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

[0056] The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as, an acknowledgement or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

Claims

The claims defining the present invention are as follows:

1. A filter unit including an enclosure comprising an inlet for receiving exhaust gases into the enclosure and an outlet to exhaust the exhaust gasses from the enclosure; and a catalysed filter insert located within the enclosure along a flow path of the exhaust gasses between the inlet and the outlet and adapted to filter said exhaust gasses, wherein the enclosure further comprises an inner and outer wall and a lid, and fittings to allow coolant to circulate through the enclosure, between the inner and outer wall and through the lid; and wherein the lid is configurable between a removed configuration, in which the lid is removed to allow the filter insert to be removed from within the enclosure, and a closed configuration, in which the lid prevents removal of the filter insert from within the enclosure.

2. The filter unit of claim 1, wherein the lid has a first and a second skin whereby coolant can circulate between the first and the second skin of the lid.

3. The filter unit of claims 1 or 2, wherein thefilter insert includes catalysed filter material inside a cylindrical casing.

4. The filter unit of claim 3, wherein the filter insert includes a handle at an end of the casing to allow the insert to be gripped and lifted clear of the enclosure.

5. The filter unit of any one of the preceding claims, wherein a thermal separation gap is provided between the filter insert and the inner wall of the enclosure.

6. A vehicle including an engine and the filter unit of any one of the preceding claims, mounted in the vehicle to filter exhaust from an engine.

7. The vehicle of claim 6, including a turbocharger connected between the engine and the filter unit arranged such that the engine exhaust passes through the turbocharger before being delivered to the inlet of the filter unit.

8. The vehicle of claim 7, wherein the turbocharger is mounted inside an explosion proof box.

9. The vehicle of any one of claims 6 to 8, wherein the fittings connect the filter unit into a coolant circuit of the vehicle.

10. An exhaust treatment assembly including the filter unit of any one of claims 1 to 5, mounted to a scrubber.

11. The exhaust treatment assembly of claim 10, wherein a minimum water level is maintained in the scrubber and a downpipe coupled to the outlet takes filtered exhaust from the filter unit down below the minimum water level so that the filtered exhaust passes through water before exiting the scrubber through an exhaust pipe.

12. A filter insert for the filter unit of any one of the preceding claims, including a casing around a catalysed material and a handle to lift the insert in and out of the enclosure.

13. The filter insert of claim 12, including a flange at a downstream end of the insert to support the insert at a base of the enclosure.

14. The filter insert of claim 13, wherein the flange projects outwardly of a side wall of the casing so that the side wall of the casing is spaced from the enclosure to define a thermal separation gap between the insert and the enclosure.