GB2156510A

GB2156510A - Dust collecting unit

Info

Publication number: GB2156510A
Application number: GB08407859A
Authority: GB
Inventors: Bernard David Clegg
Original assignee: ZEFAIR Ltd
Current assignee: ZEFAIR Ltd
Priority date: 1984-03-27
Filing date: 1984-03-27
Publication date: 1985-10-09
Also published as: GB8407859D0; GB2156510B

Abstract

A dust collecting unit having a casing within which is an impellor 5 housed in a scroll 4, the casing having an inlet on the axis of the impellor to which an inlet tube may be attached and an outlet 8 leading to a bag 17 for the collection of dust, the scroll 4 being perforated and between the scroll and the casing there being sound absorbent material 11. <IMAGE>

Description

SPECIFICATION Improvements in dust collecting units INTRODUCTION This invention relates to dust collecting units, particularly, though not exclusively, to mobile dust collecting units.

There are many instances where it is desirable, and some instances where it is necessary, to extract the dust from the atmosphere, for example, in buildings where a dust generating process is taking place. Dust extraction plant makes the atmosphere satisfactory for personnel to carry out their work and in some cases Government Regulations make it obligatory to install such plant.

Sometimes buildings are erected with dust extraction plant incorporated in the structure but in other, especially more older buildings, this is not so and dust collection apparatus has to be installed. If the building is not of sufficient size to warrant large-scale apparatus being installed, then smaller, possibly mobile, units would be suitable.

Mobile dust extraction units already proposed suffer from the disadvantage that they are noisy and this may cause considerable discomfort to personnel working nearby.

OBJECT It is the main object of this invention to provide a mobile dust extraction unit which is less noisy than previous proposals.

STATEMENTS OF INVENTION According to the present invention there is provided a dust collecting unit, including a casing within which is an impellor housed in a scroll, an inlet and an outlet leading to and from the scroll respectively and filter means connected to the outlet for the extraction and removal of dust from air moved by the impellor, characterised in that the scroll is perforated and between the scroll and casing is sound absorbent material.

The unit may be mounted on a wheeled base for mobility.

The invention also includes a dust collecting unit as above, in which the inlet has means for the connection of an inlet tube through which dust laden air is drawn, the inlet being provided with a closure flap which closes automatically on the removal of the inlet tube.

Conveniently, the flap operates by gravity.

DRAWINGS Figure 1 is a part cross-sectional side elevation of apparatus constructed in accordance with the invention; Figure 2 is an end view of the apparatus of Figure 1; Figure 3 is a plan view of the apparatus of Figure 1; Figure 4 is an enlarged part crosssectional view of the lower portion of the apparatus of Figure 2; Figure 5 is a scrap view of Figure 4; and Figure 6 is an end view of Figure 5.

SPECIFIC DESCRIPTION The dust extraction unit shown in the drawings is mobile but it will be appreciated that the invention is equally applicable to static units whether fabricated in situ or installed after erection of the structure.

The unit includes a base 1 having castors 2 for mobility. Carried on the base is a casing 3 within which is a scroll 4 housing a fan or impellor 5 driven by an electric motor 6. The scroll has an inlet 7 and an outlet 8.

The scroll is perforated as indicated at 9 and 10 and between the outer wall of the scroll and the inner wall of the casing is a sound absorbent material 11. This sound absorbent material may be mineral wool or any other packing which has the ability of absorbing and thereby deadening sound waves. The scroll may be perforated in selected areas as shown in Figure 1 or be made entirely of a perforated material.

The inlet 7 (see Figure 4) is designed to receive one end of an extraction duct or wander tube 1 2 through which dust laden air is carried to the scroll. A flap 13, hinged at 14, normally coveres all but a small area of the inlet and remains in the closed position by gravity as shown in Figures 5 and 6. However, with a tube fitted, the flap is pivoted upwards as shown in Figure 4 and is provided with a soft rubber block 1 5 which bears against the tube to prevent rattle. The flap acts to prevent inexperienced operators from gaining access to a rotating impellor via the inlet. If desired a locking means may be fitted temporarily to lock the flap in the closed position.

The outlet 8 leads to a manifold 1 5 having a quick release retaining clip 1 6 for temporarily retaining a plastics or fabric dust collecting bag 1 7 which may readily be removed when full and replaced by an emply bag. On top of the manifold is fitted a dust filter 18, probably of fabric, which is of known construction.

A dust extraction unit constructed as above has the advantage that sound generated by rotation of the impellor and the movement of dust laden air will be drastically reduced due to the absorpsion of the sound by the presence of the sound absorpsion material between the scroll and the casing, the sound waves penetrating the scroll through the perforations. Also the existence of the flap is a safety factor.

1. A dust collecting unit, including a casing within which is an impellor housed in a scroll, an inlet and an outlet leading to and from the scroll respectively and filter means connected

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements in dust collecting units INTRODUCTION This invention relates to dust collecting units, particularly, though not exclusively, to mobile dust collecting units. There are many instances where it is desirable, and some instances where it is necessary, to extract the dust from the atmosphere, for example, in buildings where a dust generating process is taking place. Dust extraction plant makes the atmosphere satisfactory for personnel to carry out their work and in some cases Government Regulations make it obligatory to install such plant. Sometimes buildings are erected with dust extraction plant incorporated in the structure but in other, especially more older buildings, this is not so and dust collection apparatus has to be installed. If the building is not of sufficient size to warrant large-scale apparatus being installed, then smaller, possibly mobile, units would be suitable. Mobile dust extraction units already proposed suffer from the disadvantage that they are noisy and this may cause considerable discomfort to personnel working nearby. OBJECT It is the main object of this invention to provide a mobile dust extraction unit which is less noisy than previous proposals. STATEMENTS OF INVENTION According to the present invention there is provided a dust collecting unit, including a casing within which is an impellor housed in a scroll, an inlet and an outlet leading to and from the scroll respectively and filter means connected to the outlet for the extraction and removal of dust from air moved by the impellor, characterised in that the scroll is perforated and between the scroll and casing is sound absorbent material. The unit may be mounted on a wheeled base for mobility. The invention also includes a dust collecting unit as above, in which the inlet has means for the connection of an inlet tube through which dust laden air is drawn, the inlet being provided with a closure flap which closes automatically on the removal of the inlet tube. Conveniently, the flap operates by gravity. DRAWINGS Figure 1 is a part cross-sectional side elevation of apparatus constructed in accordance with the invention; Figure 2 is an end view of the apparatus of Figure 1; Figure 3 is a plan view of the apparatus of Figure 1; Figure 4 is an enlarged part crosssectional view of the lower portion of the apparatus of Figure 2; Figure 5 is a scrap view of Figure 4; and Figure 6 is an end view of Figure 5. SPECIFIC DESCRIPTION The dust extraction unit shown in the drawings is mobile but it will be appreciated that the invention is equally applicable to static units whether fabricated in situ or installed after erection of the structure. The unit includes a base 1 having castors 2 for mobility. Carried on the base is a casing 3 within which is a scroll 4 housing a fan or impellor 5 driven by an electric motor 6. The scroll has an inlet 7 and an outlet 8. The scroll is perforated as indicated at 9 and 10 and between the outer wall of the scroll and the inner wall of the casing is a sound absorbent material 11. This sound absorbent material may be mineral wool or any other packing which has the ability of absorbing and thereby deadening sound waves. The scroll may be perforated in selected areas as shown in Figure 1 or be made entirely of a perforated material. The inlet 7 (see Figure 4) is designed to receive one end of an extraction duct or wander tube 1 2 through which dust laden air is carried to the scroll. A flap 13, hinged at 14, normally coveres all but a small area of the inlet and remains in the closed position by gravity as shown in Figures 5 and 6. However, with a tube fitted, the flap is pivoted upwards as shown in Figure 4 and is provided with a soft rubber block 1 5 which bears against the tube to prevent rattle. The flap acts to prevent inexperienced operators from gaining access to a rotating impellor via the inlet. If desired a locking means may be fitted temporarily to lock the flap in the closed position. The outlet 8 leads to a manifold 1 5 having a quick release retaining clip 1 6 for temporarily retaining a plastics or fabric dust collecting bag 1 7 which may readily be removed when full and replaced by an emply bag. On top of the manifold is fitted a dust filter 18, probably of fabric, which is of known construction. A dust extraction unit constructed as above has the advantage that sound generated by rotation of the impellor and the movement of dust laden air will be drastically reduced due to the absorpsion of the sound by the presence of the sound absorpsion material between the scroll and the casing, the sound waves penetrating the scroll through the perforations. Also the existence of the flap is a safety factor. CLAIMS

1. A dust collecting unit, including a casing within which is an impellor housed in a scroll, an inlet and an outlet leading to and from the scroll respectively and filter means connected to the outlet for the extraction and removal of dust from air moved by the impellor, characterised in that the scroll is perforated and between the scroll and casing is sound absorbent material.

2. A dust collecting unit as claimed in Claim 1, in which the unit is mounted on a wheeled base for mobility.

3. A dust collecting unit as claimed in either Claim 1 or Claim 2, in which the inlet has means for the connection of an inlet tube through which dust laden air is drawn, the inlet being provided with a closure flap which closes automatically on the removal of the inlet tube.

4. A dust collecting unit as claimed in Claim 3, in which the flap operates by gravity.

5. A dust collecting unit as claimed in any one of the preceding claims, in which the scroll is made entirely of a perforated material.

6. A dust collecting unit as claimed in any one of the preceding claims, in which the sound absorbent material is mineral wool.

7. A dust collecting unit substantially as herein described with reference to the accompanying drawings.