Apparatus for purifying exhaust air, in particular in sand-blasting units

(42) Date of commencement of the patent: 15.10.1992 (45) Date of issue: 25. 5.1993

<td>(30) Priority:</td><td>(73) Patent owner:</td>

<td>1. 4.1986 DE 3610780 claims.</td><td>FERTL KLAUS D-8860 NÖRDLINGEN (DE).</td>

<td>(56) Documents:</td><td></td>

<td>DE-AS 1255638 DE-AS2214435 DE-PS 916689 US-PS2414718</td><td></td>

(54) DEVICE FOR CLEANING EXHAUST AIR, ESPECIALLY FOR SANDRESTING ENVIRONMENT (57) The invention relates to a device for cleaning the exhaust air, in particular in the case of sand blasting installations. This device is a so-called wet device, which is effective from bottom to top. The object of the invention is to be seen in the improvement of the cleaning effect. For this purpose, in an intermediate piece (8), in which the air to be purified flows tangentially, baffles (37 - 40) are provided, wherein in the upper part (10) provided impeller (18) is surrounded at a radial distance from a grid that with a jacket (14) delimits a hollow cylindrical space (15) and the jacket (14) forms a further hollow cylindrical space (17) with the upper part (10), at least the latter (17) providing a drain (cf. 21) down into the water tank (4).

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AT 396 072

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The invention relates to a device for cleaning the exhaust air, especially in sand blasting machines, the from bottom to top essentially of a partially filled with water container, a cylindrical intermediate piece with a tangentially merging intake manifold and an attached upper part with an upwardly projecting discharge nozzle, the upper part being a vertical, explosion-proof and water-protected motor with impeller pointing radially from bottom to top, close to one, is either the intermediate piece or the top belonging horizontal partition, which protrudes with a connecting piece in the space of the intermediate piece

In view of the ever stricter regulations with regard to air pollution control and also with regard to the health regulations, the demands on equipment for cleaning the exhaust air, especially in sandblasting plants, are steadily increasing. As has been shown in practice, the so-called wet cleaning equipment is preferably used or in many cases it is impossible to work without water.

The initially indicated wet devices are known in various constructive embodiments and it has been shown that with respect to the cleaning effect still considerable gaps exist, d. h., It is unavoidable, in spite of the use of water, that in particular the finer dust particles of the air get into the atmosphere, which is not permitted and can lead to costly complaints. The insufficient cleaning is based mainly on the fact that the contaminated, interspersed with water air is thrown against the inner walls, where deposited solid components, part of which wegsackt down, but other parts in the air flow led up and get into the discharge nozzle.

The object of the invention is to be seen in such a way to improve a device of the type mentioned above that actually cleaned air, so air passes without exceeding the permissible limits exceeding pollution into the atmosphere. It is also an object of the invention to find a design which does not require significant additional expenditure of material and other costs and is nevertheless functionally reliable and durable.

This object is achieved in that special, tangentially provided on the inner wall and in the inflow direction of the air to be cleaned from the Zwischenstückinnenwandung wegstrebende baffles are provided in the intermediate piece, and further that the hochtourig ongoing, gfs. speed-adjustable impeller is surrounded at a radial distance of a kind of grid, which delimits a hollow cylindrical space together with a small distance all-around jacket and the mantle in turn with the inner wall of the upper part forms a further hollow cylindrical, compared to the first hollow cylindrical space voluminöseren space, said at least the latter has a drain down into the water tank. First, to prove beneficial that no particularly high construction costs are incurred here, but for a much improved cleaning effect is achieved especially therefore, because even here in the intermediate piece by the baffles, so to speak, a pre-cleaning is achieved that is, through the nozzle projecting into the intermediate piece, air which has already been partly freed from dirt particles and permeated with water, even though it is also thrown against the inner surface of the jacket lying behind the grid, However, while experiencing through the grid a kind of damping, which results in not only a good mixing of the air with the moistened impurities, but also by the different heights of the grid and the mantle the air-dirt-water mixture slightly calms the mantle, so to speak, climbed over, wherein the water-soaked particles of dirt are thrown by the centrifugal force against the inner lateral surface of the upper part, at which they sag down and get through the drain into the water tank, while the purified, at most still moisture-containing air strives for the discharge nozzle. Due to the possible speed change of the impeller, z. B. With a geared motor, the device can be adapted to the most diverse conditions, which is quite as essential to the invention and should be regarded as advantageous.

According to a further feature of the invention it is provided that the baffles, preferably curved away from the inner wall of the intermediate piece and are supported at their free ends relative to the inner wall of the intermediate piece. By the baffles the still relatively dry and polluted air is screened so to speak, so that at least the heavier components fall down into the water tank.

With regard to a pre-moistening of the air, it appears expedient that the support of the baffles, the perforated plates or lattice-like structures, done with striking plates, which preferably also perforated plates od. like. are, which connect the baffle plate ends with the intermediate piece inner wall - approximately in the radial direction. As a result, namely vortex zones, which cause the mentioned pre-moistening, the latter the more so, as by the strong suction effect of the nozzle, the pre-cleaned air enters the water intake, whereby a good moisture penetration takes place.

It is also advantageous constructively that the grid or the perforated plate and the all-around coat on the partition sessile gfs. are releasably secured and project beyond the impeller in their heights, the jacket in turn od over the grid. like. protrudes and above a inwardly directed, the inner hollow cylinder overlapping ring carries. Initially, the attachment to the partition wall is simple, which seems beneficial insofar as at least the perforated plate is subject to wear and tear and the possibility must exist to be able to easily and quickly replace this perforated plate, which is fully within the effective range of the impeller. Due to the mentioned different heights the outflow of the now

-2AT396 072B whirled up air-dirt-water mixture upwards, wherein the covering ring leads to a kind Venturi tube effect, so that above the ring, the flow rate drops and so the impurities with such a force against the Inner wall of the upper part are thrown that they are unable to drain down.

So that the noise development remains as low as possible and on the other gfs. existing unbalance vibrations of the vertical engine and / or the impeller is not transmitted to the whole device and expose this harmful vibrations is proposed according to the invention that the motor is suspended elastically with the balanced impeller, z. B. at the inner hollow cylindrical space covering ring.

In order to check the contents of the water tank and can easily refill water, it appears expedient according to the invention that the partially filled with water container carries a side, open at the top sight and / or refill, the bottom of a recess communicates with the interior of the container and the one gfs. can contain automatic Wassemachfülleinrichtung.

To avoid that the partially contaminated with heavy contaminants water in the water tank passes through the tangential entry of the air in a balancing rotary motion, it is considered advantageous that the partially filled with water container a, gfs. includes in its height adjustable brake insert, which has at least three radial, attached to a central central boom, which come close to close to the inner wall of the water tank and gfs. There with stops interacting. It is understood that you could prevent co-rotation of the brake insert by other means than with attacks. It is important, however, that you can clean the container without difficulty, so z. B. The brake insert is pulled upwards.

The previously mentioned drain from the outer hollow cylindrical space in the upper part is arranged in a simple manner by all-round openings, for. B. formed by holes in the partition Also, this measure captivates by its simplicity

In order to change the suction effect of acting on the water, projecting into the intermediate piece neck, it is proposed according to the invention to perform the projecting into the intermediate piece central neck changeable in its axial length. In this way one can also influence the relationship between water and air to be purified in a simple way.

For the cleaning of the water tank, it is favorable that the water tank is arranged swung and / or removable, or extendable on the intermediate piece

For the above-mentioned cleaning, it is also favorable for many purposes that the water tank has a conical bottom which is provided at the lowest point with a lockable spout.

Since it can not be ruled out that the whole device unintentionally changes its position due to vibration, it is finally expedient for the entire device to be designed as a stand device to be anchored to the ground

In the drawing, the invention is illustrated, for example; show it:

Fig. 1 illustrates the device according to the invention in perspective view, partially broken and partially transparent

Fig. 2 shows the basic structure of the device in section and simplified

Fig. 3 is a section along the line (ΙΠ-ΙΠ) of Fig. 2;

Fig. 4 is a section along the line (IV-IV) of Fig. 2 and

5 shows a section along the line (VV) of Fig. 2nd

As is apparent from Figure 1 and partly from the other figures, the whole device (1) on a pedestal frame (2) is constructed. Viewed from bottom to top, the device (1) consists of a partially filled with water (3) container (4), the side one, gfs. equipped with a float-operated, connected to a water supply valve visual and refill box (5) which communicates via a corresponding recess in the wall (6) of the container (4) with the water content of the container (4). The container (4) may be equipped with casters (indicated only) (7) to facilitate extension from the pedestal frame (2) when the container (4) has to be cleaned of impurities.

On the container (4) follows an intermediate piece (8) having a tangentially attached intake (9). On the intermediate piece (8) follows an upper part (10), which has an intermediate wall (11) at the bottom as a bottom, but could also belong to the intermediate piece (8) as a lid. The intermediate wall (11) carries a downwardly into the free space of the intermediate piece (8) projecting nozzle (12), is sucked through the prepurified, water-enriched air.

It is essential to the invention that on the intermediate wall (11) a kind of grid (13), z. B. an all-round perforated plate, which is releasably secured together with a likewise all-round jacket (14) delimits a hollow-cylindrical space (15). The jacket (14), in turn, defines together with the inner wall (16) of the upper part (10) a hollow-cylindrical space (FIG. 17) which is bulkier to the space (15). Grid (13) and sheath (14) surrounded with a radial distance an impeller (18) which is driven by an explosion and moisture-proof motor (19), the gfs. is variable in speed. One recognizes also that

3AT 396 072 B the grid (13) is formed lower than the jacket (14), the latter carrying a ring (20) which covers the space (15) to a certain extent. In addition, in the intermediate wall (11) holes (21) can be seen, which connect the hollow cylindrical space (17) in a sense to the cavity (22) of the intermediate piece (8). With (23) a hose is called, which receives the supply lines for the motor (19) protected. The air discharge nozzle on the upper part (10) is designated by (24).

Figures 2 to 5 show further details, which are explained in more detail in the order from bottom to top. The water tank (4) has a conical bottom (25) which is equipped with a closable outlet nozzle (26) and above all appears to be suitable for flushing the container (4) with water.

In the container (4) there is a brake insert (27) which at a central center piece at least three arms (28, 29, 30) (see. in particular FIG. 5) which cooperate with U-shaped stops (31, 32, 33) of the wall of the container (4), so that the brake insert (27) can not set in rotation and thus entgegenwiikt the rotational movement of the water and the impurities , which prevents imbalances. The brake insert (27) can be removed upwardly from the stops (31, 32, 33) and can be detachably connected at (34) to the stops (31, 32, 34). Also, the arrangement can be made so that the brake insert (27) can be adjusted in height.

When the intermediate piece (8) is to be noted that the nozzle (12) of the intermediate wall (11) is designed telescopically, ie, a sleeve-like part (35) can be moved on the neck (12) up and down, whereby the suction on the water ( 3) in the container (4) can be changed (see Figures 2 and 4).

In FIGS. 2 and 4 it can be further seen that baffles (37, 38, 39) and (40) are provided on the inner wall (36) of the intermediate piece (8), which extend away from the inner wall (36) and at their free ends with strike plates (41, 42) (only two visible in Fig. 4) relative to the inner wall (36) are supported. The baffles (37-40), which may be perforated plates or latticed structures, are used for the pre-cleaning of the polluted air flowing through the intake manifold (9).

Figures 2 and 3 can be particularly well the drain holes (21) at the bottom of the hollow cylindrical space (17) recognize. The different radial expansions of the hollow cylindrical spaces (15, 17) are just as clear.

FIG. 2 shows in the upper part (10) clearly rubber-metal parts (43) of which at least three pieces are provided which elastically hold the motor (19) with the impeller (18), namely on the ring (20) of the jacket (14 )

The device according to the invention (1) operates as follows:

When the engine is running (19) contaminated air is sucked through the intake manifold (9) and, as indicated in Figures 2 and 4, set in rotational motion, the air bounces against the perforated plates (37-40) and heavier components fall down; the latter the more so as the lower end (44) of the intake (12, 35) inflowing air supports this dropping operation. The coarse parts therefore fall into the water tank (4). The suction effect through the nozzle (12, 35) brings the surface of the water in motion, which is indicated by the irregularly curved line (45). In the process, the impurities, which have not yet been thoroughly mixed with moisture, are enriched with water and, as it were, made heavier. That in this air-water movement, the spaces behind the strike plates (41, 42) experience additional turbulence, of course

The air-water contaminant mixture, which has already been well swirled, is thrown against the jacket (14) by the impeller (18), through the grille (13), whereby further turbulence takes place, as shown by the illustrated vortex lines. By the upwardly acting impeller (18), the mixture through the constriction (46) (see. FIG. 2) pressed, whereupon immediately a radial expansion takes place, d. h., By centrifugal force the moistened impurities are thrown against the inner wall of the upper part (10), from where they sag down and pass through the holes (21) back into the cleaning cycle. Pure, carefree air strives for the discharge nozzle (24) and can get into the free atmosphere from there.