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(11) | EP 1 340 592 B1 |
| (12) | EUROPEAN PATENT SPECIFICATION |
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| (54) |
Apparatus for blasting dry ice Strahlvorrichtung mit Trockeneis Dispositif de projection de glace carbonique |
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| Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). |
[0001] The invention relates to an apparatus for blasting dry ice comprising a compressed air supply, an ice pellet supply, a mixer for mixing ice pellets and compressed air and an outlet to which a blasting pistol can be connected, which mixer comprises a disc, rotatably disposed between two non-rotatable plates, and wherein the compressed air supply and the ice pellet supply each debouch in a first of the non-rotatably disposed plates, and wherein the outlet connects to the oppositely disposed second non-rotatable plate, and wherein the rotatable disc has one or several holes which during rotation of the disc alternatingly align with the ice pellet supply on the one hand and the compressed air supply and the outlet on the other hand, wherein the compressed air supply has at least two outlets in the first non-rotatable plate.
[0002] Such an apparatus is known from the Dutch patent NL-C-1015216, and is used for blasting solid frozen carbon dioxide granules, also called pellets, with great force onto a surface to be cleaned.
[0003] From DE-A-100 36 557 an apparatus according to the preamable is known, in which the outlet is provided with at least two inlet openings in the second non-rotatable plate, arranged in pairs opposite to the outlet openings of the compressed air supply in the first non-rotatable plate, so as to form through-passages when the hole or holes in the disc are aligned with the outlet openings of the compressed air supply.
[0004] It has been shown that by doubling the number of inlet openings of the outlet, a dry ice blast twice as powerful is produced, while the amount of ice pellets supplied is the same as with an apparatus of the prior art. A further increase of the number of inlet openings of the outlet will even better this result.
[0005] It is the object of the invention to improve the known apparatus such that a more powerful and more even blast is obtained.
[0006] The apparatus according to the invention is characterized in that the said outlet openings of the compressed air supply in the first non-rotatable plate and the said inlet openings in the second non-rotatable plate are positioned diametrically in relation to one another and equidistanced from the centre of the first and second non-rotatable plate respectively.
[0007] A further advantage obtained with the apparatus according to the invention is that the blast is not only more powerful but also more even and free of pulsation in the discharged dry ice blast.
[0008] The above-mentioned advantages are achieved while maintaining the favourable properties of the apparatus known from the cited prior art. In brief these advantages are as follows.
[0009] A small amount, from 1m3/min., of compressed air enables the apparatus according to the invention to produce a powerful blast at a dry-ice consumption ranging from only 5 kg/hour up to a maximum of 40 kg/hour.
[0010] When in use, the apparatus according to the invention produces a sound pressure of approximately 79 dB(A) at a standard operating pressure of 5 bars.
[0011] The working performance of the apparatus according to the invention is further advanced by the disc being provided with a series of holes positioned at regular distances from each other and equidistanced from the centre of the disc.
[0012] The invention will now be further elucidated with reference to the drawing of a non-limiting exemplary embodiment of the apparatus according to the invention.
[0013] The drawing shows in:
- Fig. 1 a schematic cross section of the active components of the apparatus according to the invention.
- Figs. 2 and 3, respectively, a cross-section of the non-rotatable upper plate and lower plate of the apparatus according to the invention.
[0015] Referring first to Fig. 1 showing the active components of the apparatus according to the invention. These include a dual compressed air supply 1 generally connected to a common compressed air source (not shown), an ice pellet supply 2 embodied as a hopper, a mixer 3, 4, 5 for mixing the ice pellets and compressed air, and an outlet 6 to which a blasting pistol can be connected. The mixer 3, 4, 5 comprises a rotatable disc 5 disposed between non-rotatable plates 3 and 4. As can be seen in the figure, both the compressed air supply 1 and the ice pellet supply 2 each debouch in one of the non-rotatably disposed plates 3, 4, in the case illustrated this is the upper plate 3. These outlet openings are clearly shown in Fig. 2 carrying the reference numbers 1', 1'' and 2', respectively.
[0016] Referring partly also to Fig. 3, the other non-rotatably disposed plate, i.e. the lower plate 4, is provided with two inlet openings 6' and 6"for the outlet 6. In a manner quite clear to the person skilled in the art and therefore not further illustrated in the drawing, the rotatable disc 5 is provided with one or several holes which during rotation of the disc 5 alternatingly align on the one hand with the ice pellet supply 2 and on the other hand with the compressed air supply 1 and the outlet 6. As clearly shown in connection with Fig. 2 and Fig. 3, the inlet openings 6' and 6" of the outlet 6 are disposed in pairs in the extended direction of the outlet openings 1' and 1'' of the compressed air supply 1, such that when the hole or the holes align with the outlet openings 1', 1'' of the compressed air supply 1 they form through-passages. In a manner that is obvious to the person skilled in the art, the disc 5 is preferably provided with a series of holes at regular distances from one another and equidistanced from the centre of the disc, so that when the disc is being rotated, such a through-passage can be realised at high frequency.
[0017] Both Fig. 1 and Fig. 2 show that the compressed air supply 1 comprises two outlet openings 1' and 1" positioned diametrically in relation to one another. In this way the compressed air load on the rotatable disc is symmetrical, allowing it to rotate with the least possible friction between the non-rotatably disposed plates 3 and 4. Fig. 1 further shows that the non-rotatably disposed plates 3 and 4 are fixed in relation to one another by means of fixing pins 7. These pins further serve to fasten the plates 3 and 4 to each other. The pins 7 are further provided with spring rings 8 exerting a slight upward pressure that pushes the non-rotatably disposed plates 3 and 4 toward each other, so as to avoid leakage loss between these non-rotatable plates 3 and 4 and the rotatable disc 5. Fig. 1 further schematically shows that the rotating disc 5 is coupled with an air-operated engine 9. In this connection the Figs. 2 and 3 show slots 10 provided in the upper plate 3 and the lower plate 4, for venting excess driving air. The apparatus according to the invention produces an excellent, constant blast that is virtually free of pulsation.
1. An apparatus for blasting dry ice comprising a compressed air supply (1), an ice pellet
supply (2), a mixer (3, 4, 5) for mixing ice pellets and compressed air and an outlet
(6) to which a blasting pistol can be connected, which mixer (3, 4, 5) comprises a
disc (5), rotatably disposed between two non-rotatable plates (3, 4), and wherein
the compressed air supply (1) and the ice pellet supply (2) each debouch in a first
of the non-rotatably disposed plates (3), and wherein the outlet connects to the oppositely
disposed second non-rotatable plate (4), and wherein the rotatable disc (5) has one
or several holes which during rotation of the disc (5) alternatingly align with the
ice pellet supply (2, 2') on the one hand and the compressed air supply (1) and the
outlet (6) on the other hand, wherein the compressed air supply (1) has at least two
outlets (1', 1'') in the first non-rotatable plate (3), and the outlet (6) is provided
with at least two inlet openings (6', 6'') in the second non-rotatable plate (4),
arranged in pairs opposite to the outlet openings (1', 1'') of the compressed air
supply (1) in the first non-rotatable plate (3), so as to form through-passages when
the hole or holes in the disc (5) are aligned with the outlet openings (1', 1") of
the compressed air supply (1), characterized in that the said outlet openings (1',1") of the compressed air supply (1) in the first non-rotatable
plate (3) and the said inlet openings (6',6") in the second non-rotatable plate (4)
are positioned diametrically in relation to one another and equidistanced from the
centre of the first (3) and second (4) non-rotatable plate respectively.
2. An apparatus according to claim 1, characterized in that the disc (5) is provided with a series of holes positioned at regular distances from
each other and equidistanced from the centre of the disc (5).
1. Vorrichtung zum Strahlen von Trockeneis, die eine Druckluftzufuhr (1), eine Eisgranulatzufuhr
(2), einen Mischer (3, 4, 5) zum Mischen von Eisgranulat und Druckluft sowie einen
Auslass (6) aufweist, an den eine Strahlpistole angeschlossen werden kann, wobei der
Mischer (3, 4, 5) eine Scheibe (5) aufweist, die drehbar zwischen zwei nicht-drehbaren
Platten (3, 4) angeordnet ist, und wobei die Druckluftzufuhr (1) und die Eisgranulatzufuhr
(2) jeweils in eine erste der nicht-drehbar angeordneten Platten (3) münden, und wobei
sich der Auslass an die gegenüberliegend angeordnete zweite nicht-drehbare Platte
(4) anschließt, und wobei die drehbare Platte (5) ein Loch oder mehrere Löcher aufweist,
die während der Drehung der Scheibe (5) im Wechsel auf die Eisgranulatzufuhr (2, 2')
einerseits und auf die Druckluftzufuhr (1) und den Auslass (6) andererseits ausgerichtet
sind, wobei die Druckluftzufuhr (1) wenigstens zwei Auslässe (1', 1") in der ersten
nicht-drehbaren Platte (3) aufweist und wobei der Auslass (6) mit wenigstens zwei
Einlassöffnungen (6', 6") in der zweiten nicht-drehbaren Platte (4) versehen ist,
die paarweise gegenüber den Auslassöffnungen (1', 1") der Druckluftzufuhr (1) in der
ersten nicht-drehbaren Platte (3) angeordnet sind, so dass Durchlässe entstehen, wenn
das eine oder die mehreren Löcher in der Scheibe (5) auf die Auslassöffnungen (1',
1") der Druckluftzufuhr (1) ausgerichtet sind, dadurch gekennzeichnet, dass die Auslassöffnungen (1', 1") der Druckluftzufuhr (1) in der ersten nicht-drehbaren
Platte (3) und die Einlassöffnungen (6', 6") in der zweiten nicht-drehbaren Platte
(4) diametral zueinander angeordnet sind und den gleichen Abstand zur Mitte der ersten
(3) bzw. der zweiten (4) nicht-drehbaren Platte aufweisen.
2. Vorrichtung nach Anspruch 1, dadurch gekennzeichnet, dass die Scheibe (5) mit einer Reihe von Löchern versehen ist, die in regelmäßigen Abständen
voneinander angeordnet sind und den gleichen Abstand zur Mitte der Scheibe (5) haben.
1. Dispositif de projection de glace carbonique, comprenant une alimentation en air comprimé
(1), une alimentation en blocs de glace (2), un mélangeur (3, 4, 5) pour mélanger
les blocs de glace et l'air comprimé, et une sortie (6) à laquelle un canon de projection
peut être connecté, ledit mélangeur (3, 4, 5) comprenant un disque (5) disposé de
façon rotative entre deux plaques non rotatives (3, 4), et dans lequel l'alimentation
en air comprimé (1) et l'alimentation en blocs de glace (2) débouchent toutes les
deux dans une première des plaques disposées de façon non rotative (3), et dans lequel
la sortie se connecte à la deuxième plaque non rotative située en face (4), et dans
lequel le disque rotatif (5) comporte un ou plusieurs trou(s) qui, pendant la rotation
du disque (5), s'aligne(nt) alternativement avec l'alimentation en blocs de glace
(2, 2') d'une part, et l'alimentation en air comprimé (1) et la sortie (6) d'autre
part, dans lequel l'alimentation en air comprimé (1) comprend au moins deux sorties
(1', 1") dans la première plaque non rotative (3), et la sortie (6) comporte au moins
deux ouvertures d'entrée (6', 6") dans la deuxième plaque non rotative (4), disposées
par paires en face des ouvertures de sortie (1', 1") de l'alimentation en air comprimé
(1) dans la première plaque non rotative (3) de manière à former des passages traversants
lorsque le trou ou les trous dans le disque (5) est/sont aligné(s) avec les ouvertures
de sortie (1', 1") de l'alimentation en air comprimé (1), caractérisé en ce que les ouvertures de sortie (1', 1") de l'alimentation en air comprimé (1) dans la première
plaque non rotative (3) et lesdites ouvertures d'entrée (6', 6") dans la deuxième
plaque non rotative (4) sont positionnées dans une relation diamétralement opposée
l'une par rapport à l'autre et sont équidistantes du centre des première (3) et deuxième
(4) plaques non rotatives, respectivement.
2. Dispositif selon la revendication 1, caractérisé en ce que le disque (5) comporte une série de trous positionnés à des distances régulières
les uns des autres et équidistants du centre du disque (5).