NL8800724A - Filter ceiling for paint spray cabin - has filter support gauze in ceiling box, producing downward flow - Google Patents

Abstract

Motor vehicle body paint spray cabin includes rectangular box shaped air filter box with filter support gauze. Air filter system ensures dust free downwards flowing air current. Filter box protrudes from ceiling and has filter gauze fitted at sides and bottom of box, to produce a dust free air flow directed against cabin walls. Dust free air quantity and speed is sufficient to prevent any air rising along cabin walls. A floor mounted suction grid is incorporated.

Description

}

a

-1-

Short designation: Construction of the filter ceiling of a spray booth, which prevents the rising air flow along the walls.

In the car body repair business, a repaired car is finally sprayed in a spray booth.

In the manufacture of spray booths, all attention is paid to provisions to prevent dust as much as possible during spraying.

In principle, this is achieved by allowing the supplied air to enter the cabin through the largest possible filter ceiling, fitted with very high-quality filters, so that the object to be sprayed is completely in a dust-free vertical air flow.

In the attached drawing: (Fig-1) this was indicated: the clean air flow emerges from the filter ceiling according to the arrows "A". A well-known and feared phenomenon here is that this air flow at the edges of the filter ceiling causes ambient air to move according to the arrows "B" as a result of the friction. This creates an air circulation "C" between the 20. central dust-free zone and the walls: directed upwards along the walls and downwards along the edges of the ceiling filter. The air circulation "C" is further enhanced by the thermal effect of the heat from the cabin walls and the light boxes.

25. Obviously, this airflow J, C "consists of dust-rich air, originating from floors, walls and light ornaments.

It is precisely around the vehicle to be sprayed that a critical air zone is created in which dust-free and dust-rich air adjoin each other, and the painter is also at work in this area.

The manufacturer tries to counter this phenomenon, called dust air injection, in several ways: '1. By keeping the light paths as narrow as possible and thereby allowing the filter ceiling to reach as close to the wall as possible.

.880 0724

V

Ir -2- 2. Remove the heat through the light ornaments, by flushing them with dust-free air.

3. By creating an additional dust-free air flow between the lighting ornaments and the cabin walls, which 5. is directed downwards.

4. By extending the filter ceiling to the cabin walls and installing the lighting outside the cabin with glass windows in the walls.

With the first provision. relatively the best results can still be achieved; the other provisions are either impractical or more or less expensive with dubious results.

sa0 072 4 -3- *

Explanation of the design, see drawing, sketch 2:

Instead of a flat ceiling filter, this is implemented as a filter box, which protrudes below the closed cabin ceiling.

5. In addition to the bottom surface, the vertical edges of this filter box are also provided with the same high-quality filter material.

The support mesh supporting the filter material in these vertical edges must have such a passage that, depending on the total amount of feed air and the resistance over the large flat filter, the amount of dust-free air per volume passing along the vertical filter edges and speed is sufficient to counteract an increase in airflow along the cabin walls and convert it into a vertical downward airflow.

As this outer air flow progresses between filter ceiling and extraction grille in the floor, it will begin to contain more dust particles, but these will not pose a risk of dust ingress into the paintwork.

.8800724 *

Claims (2)

1. Design of the filter ceiling of a spray booth as a flat rectangular box against the ceiling, characterized in that all interfaces of this box are provided with high-quality filter material so that the air supplied via this filter box enters the cabin as dust-free air, namely via the bottom surface vertically downwards and horizontally outflowing via the upright filter surfaces in the direction of the cabin walls. 2. An embodiment according to claim 1, characterized in that the surface and the resistance of the filter carrier mesh in the various planes are dimensioned such that the horizontally emerging air flows in terms of volume and speed are able to prevent ascending air flows near the cabin walls and / or and convert it into downwardly directed airflows, with the aim of preventing air flows above the object to be sprayed which contain dust particles and which can cause dust to penetrate the paint. .880 0724