GB2063464A

GB2063464A - Apparatus for Extracting and Purifying Contaminated Air at Workplaces

Info

Publication number: GB2063464A
Application number: GB8024387A
Authority: GB
Original assignee: VENTILATOR AG
Current assignee: VENTILATOR AG
Priority date: 1979-07-25
Filing date: 1980-07-25
Publication date: 1981-06-03
Also published as: FR2462210A1; FR2462210B3; IT8035918V0; DE2930156A1

Abstract

Apparatus for extracting and purifying contaminated air and vapours at a workplace in a production area comprises a collector hood 2, filtration equipment 3, 4 and a suction fan 5 which are all arranged as a single unit particular to the workplace. <IMAGE>

Description

SPECIFICATION Apparatus for Extracting and Purifying Contaminated Air at Workplaces The present invention relates to an apparatus for extracting and purifying contaminated air and vapours at workplaces, and has particular application in extracting and purifying waste gases from a die-casting machine. The apparatus comprises an extractor or collector hood, filtration equipment, and a suction device.

The invention is concerned in particular with industrial environments and as used herein "workplaces" means one part only of a production area which has a number of workplaces. For example, a die-casting floor of factory may be regarded as a production area comprising a number of die-casting machines each at a workplace.

At the present time there is increasing interest in maintaining the cleanliness of workplaces in factory areas, in particular workplaces where dust and gases containing injurious substances are produced. Basically such measures involve preserving the health of the work-force and also keeping the production areas clean.

Known apparatus for keeping workplaces clean normally consist of extractor hoods covering one or more workplaces, the hoods being connected via a system of pipes and ducts to a central extraction unit. The gases extracted in such a way are normally vented to the outside atmosphere or passed to a special filtration unit.

Such known systems obviously have the disadvantage that they are fixed and stationary and moreover depend on the satisfactory operation of the central suction unit. It has also been found that there is a further disadvantage in the fact that on account of the extraction and venting of the contaminated air or gases, further equipment is necessary in order to supply further fresh air to the workplace or production area.

The object of the present invention is largely to obviate these disadvantages.

According to the invention there is provided an apparatus for extracting and purifying contaminated air and vapours at a workplace in a production area, said apparatus comprising a collector hood, filtration equipment and a suction fan, wherein the hood, filtration equipment and fan form a single unit particular to the workplace.

Each individual workplace that is to be cleaned is provided with such an apparatus. In this way a high degree of independence and autonomy is achieved, whereby one hood designed to cover the whole workplace is preferably provided, to which the filtration equipment, for example a prefilter and subsequent fine filter, can then be directly connected. The fan is likewise arranged directly behind the filters, means being provided in order to recirculate the purified air directly from the fan into the production area.

Suitable pre-filters are, for example, permanent filters, i.e. washable filter elements, while replaceable or disposable filter elements may be provided as the fine filter.

A flap is preferably provided in the extraction duct between the hood and fan, for example, directly in front of the pre-filter, which flap is adapted to shut off the said duct. This is useful in the event of a machine fire, whereby an unnecessary air draught can be avoided by closing the flap.

The hood itself is advantageously horizontally displaceably guided on the upper part of the apparatus.

By virtue of such a construction it is possible to retract the hood when toois on the machine have to be exchanged or replaced. The tools can then be installed and/or removed for example by means of a crane.

The possibility of being able to recirculate the purified air directly from the fan into the producton area results in a substantially reduced separate supply of fresh air, which means a not inconsiderable saving in energy.

One embodiment of the apparatus according to the invention will be described in more detail hereinafter with the aid of the drawing, in which: Figure 1 is a side view of a die-casting machine, above which an apparatus according to the invention is arranged, and Figure 2 is a purely diagrammatic front view of the apparatus according to Figure 1, the hood being shown in section.

Figure 1 of the drawing shows a die-casting machine 1 above which a suction and purification apparatus is arranged. In die-casting, especially when processing aluminium, toxic substances that are relatively aggressive are emitted. In order to protect the actual apparatus and the workforce, it is therefore essential to extract the vapours that are produced.

The apparatus shown in the drawing for extracting and purifying contaminated air or vapours consists essentially of a collector hood 2 arranged directly above the workplace of the machine 1. A duct leads directly from the hood 2 through a pre-filter 3 which removes the coarsest particles and substances. A further filter compartment is connected to the pre-filter 3, which further filter compartment in the illustrated example contains three fine filters 4.

The pre-filter 3 consists, for example, of a washable metallic pre-filter, while the fine filters 4 consist of replaceable or disposable fabric-type filters.

A radial fan 5 and associated motor is coupled directly to the filter compartment 4, and effects the air flow through the filters. The purified air is blown back into the production area through the outlet pipe 6.

Figure 2 of the drawing shows purely diagrammatically a cross-section through the extractor hood 2 over the workplace. Additional side plates or curtains 7, 8 are meant to ensure that the vapours formed can be extracted as thoroughly as possible.

The apparatus described above with reference to the drawing provides a compact construction which can be arranged easily in each case at the relevant workplace. The apparatus presents a single unit which is independent of a central extraction unit and also has the advantage that the purified air is re-circulated. Thus, not only is the workplace kept clean, but the need to provide an energy-intensive fresh air supply is also at the same time avoided.

Claims

1. An apparatus for extracting and purifying contaminated air and vapours at a workplace in a producton area, said apparatus comprising a collector hood, filtration equipment and a suction fan, wherein the hood, filtration equipment and fan form a single unit, particular to the workplace.

2. Apparatus according to claim 1 wherein a hood designed to cover the whole workplace is provided, the filtration equipment, e.g. pre-filter and fine filters, is arranged immediately after the hood, and the fan is arranged behind the filters, wherein means are provided in order to recirculate the purified air directly from the fan into the production area.

3. Apparatus according to claim 1 or claim 2, wherein one or more permanent filter elements are provided as the pre-filter, and one or more replaceable filter elements are provided as the fine filters.

4. Apparatus according to one of claims 1 to 3, wherein a flap is provided in the extraction duct between the hood and fan, e.g. in front of the prefilter, which flap can close off the duct.

5. Apparatus according to one of claims 1 to 4, wherein a radial fan is provided as the fan.

6. Apparatus according to claim 1, wherein the hood is guided for horizontal movement.