GB2071515A

GB2071515A - Vacuum loading apparatus

Info

Publication number: GB2071515A
Application number: GB7942285A
Authority: GB
Original assignee: DISAB VACUUMTEKNIK AB
Current assignee: DISAB VACUUMTEKNIK AB
Priority date: 1979-12-07
Filing date: 1979-12-07
Publication date: 1981-09-23

Abstract

Vacuum loading apparatus comprises a housing (10) having an inlet (13), vacuum means (11) for producing an air stream through the inlet into the housing and means (16, 21) for selectively causing the air stream to pass from the housing to the vacuum means either through a first flow path (15, 18) or through a second flow path (20, 23). The respective flow paths include two groups of filters alternatively usable for filtering wet or dry particulate material from the air stream apparatus, the first group of filters (15, 18) being located in the first flow path, and the second group of filters (20, 23) being located in the second flow path, each group comprising two separate filters arranged in series. Valves (17, 22) open in response to excess vacuum in respective flow paths. <IMAGE>

Description

SPECIFICATION Vacuum loading apparatus This invention relates to vacuum loading apparatus and in particular, although not so restricted, to such apparatus mounted on a motor vehicle.

According to one aspect of the present invention there is provided a vacuum loading apparatus comprising: a housing having two air inlets and an air outlet; vacuum means for producing an air stream in said housing; means for selectively causing the air stream to pass through a first flow path from one inlet to the outlet and through a second flow path from said other inlet to the outlet; a first group of filters in series for filtering particulate material from an air stream passing through the first flow path; and a second group of filters in series for filtering particulate material from an air stream passing through the second flow path.

In the preferred embodiment the first group of filters includes a dry filter for filtering air containing dry particulate material and a first control filter downstream of said dry filter. The apparatus may include a valve between said dry filter and said first control filter arranged to open when the vacuum in said first flow path exceeds a predetermined level.

In the preferred embodiment the second group of filters includes a wet filter for filtering air containing wet particulate material and a second control filter downstream of said wet filter. The apparatus may include a valve between said wet filter and said second control filter arranged to open when the vacuum in said first flow path exceeds a predetermined level.

Preferably the housing comprises a first part including said vacuum means and a second part including said first and second group of filters, the said first part being fixed and said second part being pivotally mounted.

The apparatus may include a separator having an inlet for air containing particulate material and connected to said two air inlets of the housing.

The separator may have cyclone means for filtering air containing particulate material. The separator may be connected to said second part of the housing for pivotal movement therewith.

The invention is illustrated, merely by way of example, in the accompanying drawings, in which: Figure 1 is a schematic diagram of a vacuum loading apparatus according to the present invention; Figure 2 illustrates schematically the apparatus of Figure 1 when used for filtering air containing dry particulate material; and Figure 3 illustrates schematically the apparatus of Figure 1 when used for filtering air containing wet particulate material.

Throughout the drawings like parts have been designated by the same reference numerals.

Referring first to Figure 1, there is illustrated, schematically, a vacuum loading apparatus according to the present invention. The vacuum loading apparatus is adapted to be mounted on a vehicle such as, for example, a truck or lorry (not shown) and arranged to collect wet andlor dry particulate material from, for example, industrial sites.

The apparatus consists of two flow paths A, B extending from a separator 10 to a blower 11. The blower 11 is driven by, for example, a diesel engine separate from that of the lorry of truck on which the apparatus is mounted. The flow path A is used when the particulate material being collected is essentially dry and the flow path B is used when the particulate material being collected is essentially wet, that is comprises solid particles with water or other liquid.

The particulate material is collected by means of a hose 13 connected to an inlet 12 of the separator 10.

The flow path A comprises a cyclone separating device 14 located within the separator 10, a dry filter 15,a changeover valve 16 which when open permits flow to the flow path A and which when closed prevents such flow, a safety valve 17 which is designed to open if the vacuum in the flow path A exceeds a predetermined level, for example, if the dry filter 15 becomes blocked, and a dry control filter 18. The flow path 6 comprises a wet filter 20, a changeover valve 21 interconnected with the changeover valve 16 and which when open permits flow through the flow path B and which when closed prevents such flow, a safety valve 22 similar to the safety valve 17 and designed to open if the vacuum in the flow path B exceeds a predetermined level, for example, if the wet filter 20 becomes blocked, and a wet control filter 23.The changeover valves 16, 21 are interconnected so that when the valve 16 is open, the valve 21 is closed and when the valve 16 is closed the valve 21 is open. Thus air containing particulate material from the separator 10 can pass either through the flow path A or through the flow path B but not through both flow paths simultaneously.

An unloading valve 24 is connected into the flow paths between the filters 15, 20 and the changeover valves 16, 21. The purpose of this valve is two-fold.

Firstly the valve 24 is opened upon start-up of the apparatus and until the blower 11 has reached an optimum speed and then it is closed to cause flow of air containing particulate material through one or other of the flow paths as desired. The valve 24 is also opened upon shut-down of the apparatus to avoid damage to the blower 11 resulting from it being rotated in the reverse direction by virtue of the residual vacuum in the apparatus. The second purpose of the valve 24 is as a safety valve. The vacuum or reduced pressure produced in the hose 13 connected to the inlet 12 may be relatively high and could endanger personnel operating the apparatus if they come into contact with the open end of the hose.The hose may, therefore, be provided with a "dead man's handle" connected to open the valve 24 to breakthevacuum in the hose when the dead man's handle is released. If the dead man's handle is released, the vacuum in the flow path A or B will be directly broken upon opening of the valve 24. Safety devices may be provided elsewhere on the The drawings originally filed were informal and the print here reproduced is taken from a later filed formal copy.

apparatus, operation of these safety devices also opening the valve 24 to break the vacuum within the apparatus in the event of malfunction or danger to personnel.

A conduit 25 extends from the high pressure side of the blower 11 through a valve 26 to the downstream side of the dry filter 15. When the valve 26 is open, warm air passes from the blower 11 through the conduit 25 and through the filter 15 back to the blower to dry the filter 15 in the event that it is wet. It will be appreciated that the dry filter 15 consists of relatively fine filter elements and these can become clogged relatively easily if wet particulate material is passed through the dry filter 15 accidently. To remove accumulation of particulate material on the dry filter, air pulses are blown therethrough in reverse direction, the air pulses being produced by a separate air system (not shown) controlled by a timing device.

The operation of the apparatus for filtering air containing dry particulate material will now be described with reference to Figure 2. During this operation the changeover valve 16 is open and the changeover valve 21 is closed so that air flow is through the path A. Thus air containing dry particulate material is sucked into the separator 10 by the blower 11 through the hose 13 and a proportion of the particulate material is removed by the cyclone separating device 14. The air, still containing some particulate material, passes from the cyclone separating device 14 into a chamber 30 in which is disclosed a plurality of filter tubes or bags 31 forming the dry filter 15. The air passes from the exterior of each filter bag to the interior, the interiors communicating with a chamber 32.The particulate material trapped by the dry filter 15 falls to the lower end of the chamber 30 which communicates with the separator 10 by way of a normally closed door 33. The air passes from the chamber 32 through the control filter 18, which removes any remaining particulate material which may have passed through the dry filter 15, through the blower 11 and a silencer 34 to atmosphere.

It will be seen that the conduit 25 for supplying warm air to clean and dry the dry filter 15 extends between the silencer 34 and the chamber 30. In Figure 2, the safety valve 17 and the unloading valve 24 are not shown.

The operation of the apparatus for collecting wet particulate material will now be described with reference to Figure 3. For this operation the changeover valve 21 is open and the changeover valve 16 is closed so that air flow is through the flow path B. Air containing wet particulate material is sucked into the separator 10 by the blower 11 through the hose 13 and a proportion of the water (or other liquid) and wet particulate material settles in the lower part of the separator 10. The air still containing wet particulate material leaves the separator 10 by way of a coarse screen filter 36 which traps moisture or liquid particles. The screen filter 36 is cleaned by means of high pressure water forced therethrough from a reservoir 37 by a pump 38. The air, still containing wet particulate material, enters a chamber 39 from the separator 10.In the chamber 39 there is disposed a plurality of filter tubes or bags 40 forming the wet filter 20. It will be seen that the wet filter 20 consists of fewer filter bags than the dry filter 15, but this is not essential and the - wet filter and the dry filter may have any number of filter bags as desired. The air passes from the chamber 39 through the filter bags 40 from the exterior thereof to the interior into a chamber 41. The particulate material trapped by the filter bags 40 falls to the lower part of the chamber 39 which communicates with the separator 10 by way of the door 33.

From the chamber 41, the air passes through the control filter 23, the blower 11, the silencer 34 to atmosphere.

The changeover valve 21 and the safety valve 22 are not shown in Figure 3.

The separator 10 has, as shown in Figure 3, a sensor 42 which is actuated when the material in the separator 10 reaches a predetermined level. When actuated, the sensor 42 causes the apparatus to shut down until the separator 10 has been emptied. For this purpose the separator 10 has a normally closed door 43.

The apparatus is arranged so that the part containing the separator 10, the dry filter 15 and the wet filter 20 can be tipped or pivoted about an axis 44 fixed to the chassis of the lorry or vehicle on which the apparatus is mounted. The remainder of the apparatus, that is the blower 11, the control filters 18, 23 etc. are fixed to the chassis and do not pivot. A dotted line in Figures 2 and 3 shows, to the right, those parts of the apparatus which are pivotally mounted on the chassis and, to the left, those parts which are fixed. Thus when the apparatus required emptying, the part containing the separator 10, the dry filter 15 and the wet filter 20 is pivoted about the axis 44 by an hydraulic device (not shown) and the door 43 is opened so that material in the separator 10 can be emptied out at a suitable disposal site. As this pivoting takes place the door 33 opens and the material in the chamber 30 and in the chamber 39 is emptied into the separator 10 and from thence through the door 43. A sprinkler system (not shown) may be provided around the door 43 to spray water onto the material being emptied from the separator 10 to contain dust.

The hose 13 may, for example, be of relatively large diameter and is, therefore, supported from the apparatus by an hydraulically extensible boom (not shown) to facilitate manoeuvring during operation of the apparatus.

Claims

1. Vacuum loading apparatus comprising: a housing having two air inlets and an air outlet; vacuum means for producing an air stream in said housing; means for selectively causing the air stream to pass through a first flow path from one inlet to the outlet and through a second flow path from said other inlet to the outlet; a first group of filters in series for filtering particulate material from an air stream passing through the first flow path; and a second group of filters in series for filtering particulate material from an air stream passing through the second flow path.

2. An apparatus as claimed in claim 1 in which the first group of filters includes a dry filterforfilter- ing air containing dry particulate material and a first control filter downstream of said dry filter.

3. An apparatus as claimed in claim 2 including a valve between said dry filter and said first control filter arranged to open when the vacuum in said first flow path exceeds a predetermined level.

4. An apparatus as claimed in any preceding claim in which the second group of filters includes a wet filter for filtering air containing wet particulate material and a second control filter downstream of said wet filter.

5. An apparatus as claimed in claim 3 including a valve between said wet filter and said second control filter arranged to open when the vacuum in said first flow path exceeds a predetermined level.

6. An apparatus as claimed in any preceding claim in which the housing comprises a first part including said vacuum means and a second part including said first and second group of filters, the said first part being fixed and said second part being pivotally mounted.

7. An apparatus as claimed in any preceding claim including a separator having an inlet for air containing particulate material and connected to said two air inlets of the housing.

8. An apparatus as claimed in claim 6 in which the separator has cyclone means for filtering air containing particulate material.

9. An apparatus as claimed in claim 6 when dependent upon claim 5 or claim 7 in which said separator is connected to said second part of the housing for pivotal movement therewith.

10. Vacuum loading apparatus substantially as herein described with reference to and as shown in the accompanying drawings.

New claims or amendments to claims filed on 21/10/80.

Superseded claim 1.

1. Vacuum loading apparatus comprising: a housing having two air inlets and an air outlet; vacuum means for producing an air stream in said housing; means for selectively causing the air stream to pass through a first flow path from one inlet to the outlet and through a second flow path from said other inlet to the outlet, the first and second flow paths being entirely separate from one another; a first group of filters in series for filtering particulate material from an air stream passing through the first flow path; and a second group of filters in series for filtering particulate material from an air stream passing through the second flow path.