DE102016006939A1 - Plant for the production of dry ice granules, dry ice granules and use of dry ice granules for the treatment of piece and / or bulk material - Google Patents

Abstract

When using dry ice granules (11) to treat chunk and / or bulk material (102), the treatment is deburring the chunk and / or bulk material (102) and the dry ice granule (11) has a dry ice snow content of less than 5% up. The dry ice granules (11) are made by a device (1) for producing a dry ice block or ring (10) having a dry ice snow content of less than 5%, followed by crushing (12) the resulting dry ice block or ring (10) into one Dry ice granules (11). A plant for producing dry ice granules (11) from a dry ice block or ring (10) comprises at least one device (12) for comminuting the manufactured dry ice block or ring (10) into dry ice granules (11).

Description

The invention relates to the use of dry ice granules for the treatment of loose and / or bulk material, dry ice granules and a plant for producing dry ice granules.

Devices for producing dry ice are known in the art. Such dry ice can be further processed into so-called pellets, which can be used for treating surfaces. For example, the DE 18 91 822 U1 a device for producing dry ice blocks from liquid, cold low-pressure carbonic acid in a press, a supply line for the liquid carbonic acid, a discharge line for the partial expansion of the liquid carbonic acid formed in the press room gaseous carbon dioxide, a piston for pressing the resulting carbon dioxide snow to solid Dry ice blocks and valves in the supply and discharge line has. A disadvantage in this device proves that carbon dioxide snow is formed, which is pressed into blocks only subsequently, since the blocks formed usually have no homogeneous consistency. Furthermore, when relaxing liquid carbon dioxide only 40 to 50% of the liquid carbon dioxide go into solid dry snow, the remaining 50 to 60% in the gaseous state. This part is either completely lost or can be collected and re-liquefied. To make this more efficient, the DE 10 2011 014 327 A1 to lead the liquid carbon dioxide under tank pressure or via an additional pumping device via a supply line and several connections in an apparatus with a plurality of through holes. The liquid carbon dioxide is pre-cooled prior to introduction into the apparatus to below the limit, in which the liquid carbon dioxide passes into the solid state. During the introduction of carbon dioxide, the passage openings of the apparatus are sealed on the outside pressure-tight. In or near the apparatus, a cooling device is provided by means of which the carbon dioxide in the apparatus is cooled so far that it passes into solid dry ice. To eject the dry ice is a pressing device.

It is thus known to relax liquid carbon dioxide under atmospheric pressure to produce dry ice snow, and to press this into pellets having a temperature of -79 ° C and a hardness of 2 to 2.4 Mohs. Such dry ice pellets can be used as blasting agents to clean surfaces, but are too soft to be abrasive when compared to other blasting media. Such dry ice pellets are therefore used only for cleaning purposes.

It is an object of the present invention to provide a dry ice granule improved over the prior art and a further use of the dry ice granules for the treatment of unit load and / or bulk material and a plant for producing the dry ice granules.

The object is achieved according to claim 1 by the use of dry ice granules for the treatment of unit and / or bulk material in that the treatment of the piece and / or bulk material is a deburring and the dry ice granules has a dry ice snow content of less than 5%. The object is achieved according to claim 4 by a dry ice granules, prepared by means of a device for producing a dry ice block with a dry ice snow content of less than 5% with subsequent crushing of the resulting dry ice block to granules. The object is achieved for a plant according to claim 6 for the production of dry ice granules from a dry ice block or ring, comprising at least one device for comminuting the dry ice block or ring produced to dry ice granules. Further developments of the invention are defined in the dependent claims.

As a result, dry ice granules are provided, which is significantly more stable or solid than dry ice pellets of the prior art. The dry ice granules are made into granules using a device for producing blocky dry ice and comminuting it. The device for producing the dry ice block advantageously comprises at least one pressure vessel for receiving liquid carbon dioxide. To prevent the formation of carbon dioxide snow, at least one device is advantageously provided, by means of which the pressure vessel can be filled or filled with a medium under pressure before the carbon dioxide is introduced. Furthermore, at least one further device is advantageously provided, by means of which the carbon dioxide in the pressure vessel against the medium pressure and displacing the medium from the pressure vessel can be filled or filled. The pressure vessel is used to hold liquid carbon dioxide and is advantageously formed at least double-walled, thus preferably comprises at least one inner tube and at least one outer tube. The inner tube has an inner lumen, so an inner cavity, for receiving the carbon dioxide. Between the inner tube and the outer tube, a coiled space is advantageously left for passing at least one refrigerant to provide a cooling jacket of the pressure container for cooling the liquid carbon dioxide absorbed in the interior, so that it passes from the liquid to the frozen state.

The dry ice block or ring provided in the device can be discharged from the device continuously or discontinuously. A dry ice block as well as a dry ice ring are therefore understood to mean both a block or ring of a defined length and an endless block or endless ring which results from continuous operation of the device or continuous expulsion of the dry ice produced from the device.

Still in or out of the device, it is subsequently placed in the form of granules using the apparatus for crushing the dry ice block. This can be done continuously or discontinuously. In continuous operation, the dry ice produced, particularly in a horizontal orientation, is introduced into the apparatus and continuously comminuted therein as it passes therethrough such that at the end of the apparatus the desired granule exits or is removable from the apparatus. Both the introduction of the dry ice into the device and the comminution process can be carried out continuously. In a batch operation, a dry ice block is introduced into the device, crushed therein and can be removed again after granulation of the device.

The produced dry ice block or the dry ice produced and accordingly also the dry ice granules produced from this is produced without emergence of dry ice snow, ie without relaxing the carbon dioxide, so that the resulting dry ice granules has such a hardness that it is for knocking off burrs and nubs on the surface of piece and bulk material projecting and should be separated, thus for abrasive processing of bulk and piece goods, can be used. Upon drying, the dry ice granules pass into the vapor phase, so that after separation of the burrs and nubs no granules remain, only the separated burrs and nubs, which can be removed from the device or plant.

The dry ice granules produced can be particularly advantageous for removing burrs and other from the surface of die-cast, sand casting, injection molding, in particular zinc die-cast, and / or good at least one metal, in particular non-ferrous metal, and / / or at least one plastic, in particular elastomeric material, such as rubber, or polyurethane, to be removed elements to be used. In particular, it has a hardness of more than 3 Mohs, in particular more than 5 Mohs, and / or a density of at least 1,600 kg / m ³ , in particular more than 1,600 kg / m ³ . Such a hardness or density can be produced by producing the dry ice or dry ice granules without relaxing the carbon dioxide, that is to say preventing the formation of carbon dioxide snow.

Advantageously, at least one device for deburring bulk and / or bulk material by means of dry ice granules is provided, wherein the device comprises at least one device for accelerating the dry ice granules for spin-coating thereof onto the piece to be deburred or abraded, protruding from protruding ridges and knobs - and / or bulk material. In particular, the device for accelerating comprises at least one centrifugal wheel and / or at least one injection gun or a part of an injection gun. Either the plant for producing dry ice granules may comprise such a device for deburring with at least one device for accelerating or such may be provided in addition to the plant, in particular remote from it. For example, one device or plant can only serve to produce the dry ice, and a second device can be provided for comminuting the resulting dry ice block or ring. Following this or away from this, the device may be provided for deburring the piece and / or bulk material. The individual devices can be provided at different locations, even far away from each other, depending on the particular application. The device for accelerating may in particular comprise a blast wheel and / or an injection gun and / or a part of an injection gun, so that the dry ice granules can be spun onto the piece and / or bulk material to be deburred by means of the blast wheel or the injection gun, to remove the protruding burrs or nubs etc. of this. In particular, a mixture of strongly cooled air and / or refrigerant and dry ice granules is spin-coated as a blasting agent, wherein the refrigerant or the highly cooled air for embrittlement of burrs, nubs etc. to be hammered off serves. If a mixture of refrigerant or cooled air and dry ice granules is used, additional charging of the unit and / or bulk material with refrigerant for embrittlement of the ridges, nubs etc. to be separated can be dispensed with.

Such ridges, knobs, etc. remain in particular after removal of the piece and / or bulk material in the form of a casting or molded part as excess material on the surface of the piece and / or bulk material are and must therefore be removed.

It proves to be particularly advantageous if the device for accelerating a central supply for refrigerants, in particular nitrogen, in particular when the device is designed for accelerating in the form of a centrifugal wheel. By supplying refrigerant centrally in the spinner, the refrigerant for embrittling the burrs and nubs to be separated, or elements generally projecting from the surface and being removed, can be accelerated along with the dry ice granules toward the burrs and nubs.

It is a wear-free deburring of both elastomers, such as rubber, as well as other plastics, diecasting material, such as zinc diecasting, sand casting and injection molding, and Good of one or more metals, especially non-ferrous metals, such as aluminum, Zinc, etc., when using the dry ice granules possible.

The means for accelerating advantageously has at least one inlet opening for introducing dry ice granules and at least one outlet opening for the exit of dry ice granules, at least one lock part between the inlet opening and the outlet opening and at least one device for generating a negative pressure in the lock part, wherein the inlet opening and the outlet opening are arranged at a small distance from each other. By providing a small distance between the inlet opening and outlet opening, it is possible that the blasting agent in the form of dry ice granules does not act on the impeller. Possibly. For example, the blast wheel can be rotated more quickly compared with use with another blasting medium, to safely avoid impinging the blast wheel with the dry ice granules.

More preferably, the inlet opening of the means for accelerating may be slit-shaped to provide a small inlet for the dry ice granules and to draw little air through this inlet opening together with the dry ice granules into the interior of the spinner wheel. The at least one outlet opening preferably has a larger dimension than the at least one inlet opening, in particular is funnel-shaped or formed as a funnel-shaped channel. In this way, a particularly broad-angle and therefore good discharge of the accelerated in the centrifugal dryer dry granules from this into a treatment chamber, in particular a processing drum, arranged therein to be deburred bulk or piece goods. In order to provide a short path between the outlet of the dry ice granules from the impeller and the inlet thereof, the inlet opening for the dry ice granules may be arranged close to the outlet opening, in particular the funnel-shaped outlet opening or the funnel-shaped channel.

Instead of a blast wheel, an injection gun or a part thereof may be provided for accelerating the dry ice granules. Here, the dry ice granules can be sucked in via a device and centrifuged together with the air onto the piece or bulk material to be deburred. The dry ice granules can be sucked when passing through the cooled air under the action of an occurring or acting negative pressure and carried along with the air flow. Here, the cooled air can be passed through a nozzle-like device and be spun by this together with the dry ice granules on the piece or bulk to be deburred. The device may be an injection gun or part of such. Advantageously, this can be operated manually and / or by machine. In particular, a purely mechanical deburring of the piece or bulk material to be deburred may also take place. In this case, a device for switching between a manual and a mechanical operation can be provided. The device is in particular designed so that a negative pressure, in particular by the flowing through cooled air, generated and used for sucking the dry ice granules. As a result, the desired result of the simultaneous short strong cooling and irradiation of the ridges and knobs to be separated off can be achieved in a simple manner. Instead of providing a device for sucking the dry ice granules and accelerating the cooled air, two separate or combined devices can be provided in principle, each having a partial function.

The air provided for cooling or embrittlement of the burrs or nubs on the piece or bulk material can first be compressed, then dried, subsequently the pressure is reduced and the air is cooled. Thus, it is possible to use the principle of a refrigeration machine, using at least one compression or compression device, a condenser as a drying device and a pressure reducer of whatever kind. The cooling system for cooling the air may comprise at least one coil through which air can pass and which can be brought into contact with a refrigerant, or in particular with liquid nitrogen. For cooling the air, this can therefore be introduced into at least one coil, which is passed through a refrigerant such as liquid nitrogen. Pressure and / or temperature of the air can be varied and thus adjusted by the level of the refrigerant surrounding the coil. In particular, the at least one coil of copper, in order to provide a rapid cooling of the air can. To adjust the temperature of the air can also the speed at which this is passed through the at least one coil, varies and thus adjusted. Instead of the liquid nitrogen, another refrigerant can be used, wherein the cooled air has a temperature such that burrs and nubs z. B. embrittled to elastomer and plastic parts when sweeping or irradiating or impinging with the cooled desire and can be separated accordingly.

Preferably, in the apparatus for producing the dry ice block, not only a continuous coiled or threaded space is formed along the longitudinal extension of the pressure vessel, but in sections a plurality of threaded interspaces, each with at least one inlet opening and at least one outlet opening for introducing and carrying refrigerant , This makes it possible to achieve as even cooling of the liquid carbon dioxide over the longitudinal extent of the pressure vessel, since sections always fresh cold refrigerant for cooling the liquid carbon dioxide in the container wall or the respective thread gap, which is arranged there initiated and that due the heat absorption from the liquid carbon dioxide heated refrigerant is discharged again.

Due to the uniform external cooling of the lateral surface of the pressure vessel, it is possible to form a homogeneous dry ice mass in the interior of the pressure vessel. In particular, it is possible to form one kilogram of solid carbon dioxide very efficiently from one kilogram of liquid carbon dioxide, which is not possible with the devices of the prior art.

In order to quickly form a homogeneous ice mass in the core of the forming dry ice depending on the selected diameter or clear width of the inner lumen of the inner tube of the pressure vessel, it proves to be further advantageous to arrange at least one core unit in the inner lumen of the inner tube for the supply of Cold in the space between the core unit and the inside of the inner tube of the outer wall or of the jacket of the pressure vessel. The core unit advantageously has at least one coiled passage for the passage of refrigerant inside, wherein here as well, a supply and discharge of refrigerant via corresponding openings or supply lines can be provided in order to uniformly or homogeneously cool the liquid carbon dioxide to dry ice allow and avoid gas bubbles safely.

To support the discharge or to initiate the discharge of the produced dry ice from the pressure vessel, at least one pressure device can be provided, in particular a hydraulically and / or pneumatically operable or operated pressure device, which is arranged in particular in the region of the inlet side of the pressure vessel. In this case, the pressure device may in particular be connected to at least one cover element which serves to close the inlet side, in particular of the pressure vessel, so that the pressurized container of the frozen carbon dioxide, ie dry ice, is set in motion or forced out of the pressure vessel by pressurizing the lid element , When a conical shape of the innermost or inner tube of the outer wall of the pressure vessel is provided, a slight pushing or pressing and movement of the frozen carbon dioxide is sufficient to set it in motion, so that it subsequently autonomously moves out of the pressure vessel. By applying the dry ice with the pressure force exerted by the particular hydraulically and / or pneumatically operated or operable pressure device, by a few millimeters, in particular 10 mm, the inside of the inner tube of the outer wall of the pressure vessel or the outside of the dry ice is heated light, so that any sticking of the dry ice on the inside of the inner tube of the outer wall of the pressure vessel lifted and a quick discharge of dry ice is made possible from the pressure vessel.

The at least one pressure device can not only be provided on the at least one cover element acting on the inlet side of the pressure vessel, but also exert pressure on the core unit if this is desired for accelerated discharge of the dry ice from the pressure vessel.

The pressure vessel can be set up not only in a vertical position, but also in horizontal or horizontal position in order to continuously or endlessly frozen carbon dioxide, ie dry ice, drive out of the pressure vessel or can pull out about this. In this case, it is particularly possible to form the pressure vessel without a core unit and to provide endless driving, for example, a pull-out mandrel or a device for endless drawing using pistons, which are moved via an eccentric drive. The advantage of using an eccentric drive is a variable travel and variable speed of a piston connected thereto. In particular, two pistons can be arranged at a distance from one another in the inner tube or innermost inner tube of the pressure vessel, in each case sealed against the inner side thereof. The connected to the eccentric piston is movable over this. The at least one further piston is advantageously at a distance from that on the eccentric drive arranged piston connected to a counter-pressure against a pushing into the interior of the pressure vessel causing counter holding device. Such a counter-holding device serves to prevent expulsion of the carbon dioxide inside the pressure vessel during the freezing of this at the beginning of the dry ice production. The counter-holding device thus serves to enable a complete freezing at the beginning of the dry ice production, since this prevents premature expulsion of the carbon dioxide from the interior of the pressure vessel.

Between the two or the at least two pistons, which is connected to the counter-holding device and connected to the eccentric piston, is advantageously provided a gap with at least one inlet opening for pressurized carbon dioxide to the space between the at least two pistons with pressurized To fill carbon dioxide. In order to avoid an unwanted escape of the introduced into this gap carbon dioxide, the inlet opening for supplying the carbon dioxide is advantageously provided with a check valve. Upon movement of the piston connected to the eccentric drive thereby applying a force on the piston of the retainer is enabled.

A sealing of the at least two pistons relative to the inside of the inner tube of the pressure vessel is effected by means of suitable seals, in particular by Teflon seals. These can be arranged in corresponding outside grooves of the at least two pistons.

For determining the filling amount of liquid carbon dioxide in the pressure vessel can be provided at least one weighing device, in particular a weighing device with a limiting device for switching off the supply of liquid carbon dioxide in the pressure vessel, in particular the free inner lumen of the inner tube of the pressure vessel, so the remaining space between the inner lumen of the inner tube of the pressure vessel and the core unit arranged therein. By providing such a weighing device, it is possible to fill only so much liquid carbon dioxide in this space of the pressure vessel that it is completely filled, overfilling is avoided, and thus an optimum amount of dry ice from the filled liquid carbon dioxide can be formed. To switch off the supply of carbon dioxide, in particular a pressure switch can be provided.

As an alternative to a weighing device or possibly in addition to this, advantageously at least one storage and equalizing reservoir can be provided with a biasing gas which can be connected or connected to the inner lumen of the pressure vessel via at least one valve. Via the valve and / or a pressure indicator and / or a limiting device, the supply of biasing gas can be switched off as soon as the pressure vessel is filled so far with the biasing gas as the optimum or maximum filling level of liquid carbon dioxide should correspond. The storage and surge tank filled with the bias gas first serves to charge pressurized bias gas into the pressure vessel at a similar or the same pressure, as hereinafter has the carbon dioxide to be introduced there. If the pressure vessel or its inner lumen available for receiving carbon dioxide is completely filled with the biasing gas, the valve for supplying biasing gas is advantageously closed and a valve for introducing the liquid carbon dioxide into the inner lumen of the pressure vessel can be opened. The liquid carbon dioxide is advantageously at the same or about the same pressure as the biasing gas in the pressure vessel. The supply of bias gas in the pressure vessel is closed via the valve or the pressure gauge or the limiting device. About a blow-off valve, the biasing gas can be pushed back into the storage and expansion tank when filling the liquid pressurized carbon dioxide into the inner lumen of the pressure vessel. Since the biasing gas is under the same or a slightly higher pressure than / as the liquid carbon dioxide, it does not occur when introducing the liquid carbon dioxide into the inner lumen of the pressure vessel to precipitate carbon dioxide snow, but the liquid carbon dioxide remains in the liquid state. It is therefore always pressed against the pressure of the biasing gas, the pressurized carbon dioxide into the inner lumen of the pressure vessel into it. The maximum charge of liquid carbon dioxide is contained in the storage and surge tank once the bias gas is fully pushed back into the storage and surge tank. Accordingly, the filling amount or maximum filling amount of liquid carbon dioxide in the inner lumen of the pressure vessel can be controlled via the filling amount of the filled with the biasing gas storage and expansion tank, since the biasing gas always pressed first from the storage and expansion tank into the inner lumen of the pressure vessel and subsequently pushed back by the incoming liquid carbon dioxide into the inner lumen of the pressure vessel out of this out into the storage and expansion tank. As the bias gas, for example, nitrogen (N ₂ ) can be used.

For the supply of liquid carbon dioxide in particular a solenoid valve may be provided, as well in the supply of the biasing gas in the inner lumen of the Pressure vessel and return from this in the reservoir and expansion tank. This makes a particularly effective and safe switching of the supply of carbon dioxide and bias gas possible. By advantageously providing a pressure relief valve in the supply line for supplying the carbon dioxide, in particular in conjunction with a pressure reducer, the pressure difference between the biasing gas pressure and the pressure of the carbon dioxide can be controlled. Preferably, this is at a maximum of 1 bar, to avoid a relaxation of the carbon dioxide and, accordingly, an attack of carbon dioxide snow. Accordingly, the dry ice snow content can be kept below 5%, especially about 0%, corresponding to the dry ice granules formed by crushing from the dry ice. The dry ice granules advantageously has a for deburring of piece and / or bulk material, such as moldings, suitable grain size, for. B. a grain size of 0.5 mm to 5 mm or larger, in particular 0.7 to 1 mm.

For a more detailed explanation of the invention, an embodiment of this will be described in more detail below with reference to the drawings. These show in:

1 a sketch-like longitudinal sectional view of a plant according to the invention with a device for producing dry ice and a device for producing dry ice granules from the produced dry ice,

2 a sketchy view of a device according to the invention for accelerating the produced dry ice granules in the form of a blast wheel, and

3 a sketchy view of a device according to the invention for accelerating the dry ice granules produced in the form of an injection gun.

1 shows a device 1 for producing dry ice, one in the apparatus 1 prepared, already taken from this dry ice block or ring 10 and dry ice granules 11 by crushing the dry ice block or ring 10 arises. The crushing of the dry ice block or ring 10 takes place in particular by machine, but may also be done manually if necessary. One or more devices used for crushing 12 are in 1 merely indicated as lightning arrows. The device 1 includes a pressure vessel 2 , a storage tank and reservoir 3 with bias gas, such as nitrogen (N ₂ ), and a reservoir 4 with liquid carbon dioxide (CO ₂ ). The storage and equalization tank 3 is via a supply line 30 with an inner lumen 20 of the pressure vessel 2 connected. With this inner lumen 20 of the pressure vessel 2 is also the reservoir 4 via a supply line 40 connected. Both supply lines 30 and 40 are each through a valve 31 respectively. 41 , which may be in particular a solenoid valve, closable and openable.

The pressure vessel 2 has a double-walled outer wall 21 on, being between an inner tube 22 and an outer tube 24 a coiled extending space 26 is provided. On the outside, an additional insulated jacket may be the outer tube 24 surround. The coiled space 26 serves to pass a refrigerant. As 1 can be further taken along the longitudinal extent of the pressure vessel 2 three sections, each with a separate coiled space 26 , each one an inlet opening 27 and an outlet opening 28 has provided. The respective inlet opening 27 serves to supply a fresh refrigerant and the respective outlet opening 28 serves to lead out due to the heat transfer from the in the inner lumen 20 of the pressure vessel 2 charged carbon dioxide heated refrigerant. It is thus always comparatively cold refrigerant for heat absorption from the cooled carbon dioxide available. Accordingly, a homogeneous cooling of the in the inner lumen 20 of the pressure vessel 2 filled liquid carbon dioxide over the entire longitudinal extension of the pressure vessel 2 done away.

To also inside the pressure vessel 2 and, accordingly, the forming dry ice formed upon cooling of the liquid carbon dioxide, to allow homogeneous cooling, is centrally in the interior of the pressure vessel 2 arranged a core unit 5 intended. The core unit 5 is also inside with one or more coiled aisles 50 provided through which also refrigerant can be passed. As a result, a supply of refrigerant is also in the interior of the pressure vessel 2 possible, on the one hand, to ensure that the carbon dioxide passes evenly into the frozen state and, on the other hand, prevents the formation of gas bubbles. Such would be to be feared in case of uneven cooling, since then some of the carbon dioxide passes into the gas phase if necessary. To also inside the pressure vessel 2 Always provide over the longitudinal extent of the pressure vessel away as uniform a quantity of refrigerant available with an approximately the same temperature, can also over the longitudinal extent of the pressure vessel 2 or the core unit 5 a plurality of coiled aisles having respective inlet openings and outlet openings for introducing and discharging refrigerant into and out of the respective coiled aisles (s) 50 be provided. In 1 are merely examples of the inlets 51 and outlet openings 52 indicated. The at least one coiled or helical gear 50 the core unit 5 is in this z. B. provided by Aussparen or cutting.

For better removal of the formed dry ice block, the inner tube 22 on its inside 122 be conically shaped. The core unit 5 is advantageously not cylindrical, but also tapered, wherein the cone shape is reversed to that of the inner tube 22 is provided.

To peel off the dry ice from the inside 122 of the inner tube 22 and the outside 53 the core unit 5 To apply required force is a printing device 6 intended. This acts on a cover element 7 one.

The cover element 7 closes the upper inlet opening 120 of the pressure vessel 2 , The outlet opening 121 is from a second cover element 8th locked.

The printing device 6 acts as in 1 sketchily indicated on the annular cover element 7 and thereby sets that in the interior of the pressure vessel or its inner lumen 20 formed dry ice in motion, so this dissolves from the inside 122 of the inner tube 22 ,

Instead of the action of the printing device 6 only on the annular cover element 7 can cover element 7 and core unit 5 also be connected to each other, so that when exposed to the printing device 6 on the lid element 7 , which is then formed circular in plan view, both the lid member and the core unit in the direction of the outlet opening 29 to be moved. Is, however, an annular cover element 7 provided, becomes the core unit 5 advantageous over fastening webs, in 1 are not indicated, on the remaining part of the pressure vessel 2 , held.

For the production of dry ice, first the pressure vessel with the biasing gas from the storage tank and expansion tank 3 , in particular with nitrogen, filled. The biasing gas is advantageously neutral and can also be cold air. It is used to fill the pressure vessel or its inner lumen 20 with a pressurized gas, wherein the pressure is as nearly as possible identical or identical to the pressure with which the carbon dioxide is subsequently introduced into the pressure vessel. The flood of the inner lumen 20 of the pressure vessel 2 With the biasing gas being at about the same pressure as the carbon dioxide to be charged, the carbon dioxide will cause the pressure of the biasing gas to flow into the inner lumen 20 of the pressure vessel 2 is filled and thereby a relaxation of the carbon dioxide is prevented. In a relaxation of the carbon dioxide would otherwise arise carbon dioxide snow, but this should be prevented. After filling at a predeterminable pressure, for example 15 bar, biasing gas into the inner lumen of the pressure vessel, the supply of biasing gas, thus the valve 31 getting closed.

Subsequently, the valve 41 for filling the carbon dioxide in the inner lumen of the pressure vessel 2 be opened. The carbon dioxide is at about the same pressure, in particular also a pressure of 15 bar at a bias gas pressure of 15 bar, in the inner lumen 20 of the pressure vessel 2 filled. In order to allow only a small difference between the pressure of the CO ₂ and the pressure of the biasing gas, can in the supply line 40 for feeding the carbon dioxide into the inner lumen 20 be provided a pressure relief valve or a pressure reducer to the pressure vessel to the carbon dioxide as possible with a low differential pressure to that in the inner lumen 20 to fill the biasing gas located there pressure vessel. For example, a pressure difference of only 1 bar can be set. While filling the carbon dioxide into the inner lumen 20 of the pressure vessel can be over the valve 31 or another valve located in a return line for returning the bias gas into the storage and surge tank 3 is provided, the carbon dioxide, the biasing gas in the storage and expansion tank 3 Press back. The storage and equalization tank 3 It also serves as a measuring device for that into the inner lumen 20 of the pressure vessel 2 filled carbon dioxide, since due to the approximately equal pressure and the pre-filling of the inner lumen 20 of the pressure vessel 2 with the bias gas just as much bias gas back into the storage tank and expansion tank 3 is pushed back, as carbon dioxide into the inner lumen 20 of the pressure vessel 2 is filled. Accordingly, this can be prevented overfilling of the pressure vessel with carbon dioxide, since the carbon dioxide supply can be interrupted, in particular via the valve 41 As soon as the bias gas returns to the storage tank and expansion tank 3 completely pushed back. There may also be a buffer volume of biasing gas in the upper region, ie in the region of the inlet opening 120 of the pressure vessel 2 remain, if desired, to avoid overfilling the pressure vessel with carbon dioxide in any case.

Overfilling of the pressure vessel with carbon dioxide can also be prevented by providing a weighing device, in particular by suspending the pressure vessel in strain gauges, for example, so as not to impair weighing. The weighing process can be started as soon as the supply of carbon dioxide through the supply line 40 into the inner lumen 20 of the pressure vessel 2 is started. In the area of the supply line 40 or of the valve 41 For example, a pressure switch can be provided which, upon reaching the intended amount of carbon dioxide in the inner lumen 20 of the pressure vessel shuts off the supply of carbon dioxide. Furthermore, in the area of the supply lines 40 respectively. 30 a sensor or pressure switch are provided which controls the supply of carbon dioxide upon reaching the respective inlets or outlets of the supply lines 30 respectively. 40 in the pressure vessel or its inner lumen 20 through that into the inner lumen 20 of the pressure vessel 2 filled carbon dioxide shuts off. The valve 41 can from the pressure vessel, so the biasing gas therein once this completely out of the inner lumen 20 of the pressure vessel 2 is pushed out. The supply of carbon dioxide is thus switched off.

The outer wall 21 or the outer jacket of the pressure vessel 2 can be vacuum insulated to isolate the pressure vessel to the outside, thus cooling losses through the outer wall 21 to avoid the outside.

The refrigerant may also be carbon dioxide or another refrigerant used in conventional chillers.

Alternatively to the in 1 shown pressure vessel 2 can such a one without an inner core, so the core unit 5 , trained, arranged horizontally and provided with a pull-out mandrel to this over continuously or endlessly frozen carbon dioxide, so dry ice to be able to pull out of the pressure vessel. As a result, a continuous horizontal spreading of frozen carbon dioxide from the pressure vessel is thus possible. Thus, on the one hand discontinuously dry ice with the in 1 shown device or continuously continuously by horizontally arranging such a pressure vessel without the core unit 5 is trained. A crushing of the dry ice produced can also be continuous, ie continuous or continuous, or discontinuous, that is not continuous.

The 2 and 3 show two embodiments of a device for accelerating the dry ice granules produced 11 for deburring in a treatment drum 101 arranged piece or bulk material, indicated here by a molding 102 , To 2 is the means for accelerating the dry ice granules produced 11 a blower wheel 103 , according to the design 3 an injection gun 104 , which is only hinted at there.

To 2 is the blower wheel 103 in a housing 105 arranged. The blast wheel comprises a number of arms or blades 106 around a central axis of rotation 107 are arranged around. In the area of the central axis of rotation, ie in the center of the blast wheel 103 , is an outlet 108 for the discharge of refrigerant, in particular nitrogen (N ₂ ), provided. This can thus centrally in the interior of the spinner 103 an influx of refrigerant passing through the impeller into the interior of the treatment drum 101 can be provided. The housing 105 the blower wheel 103 is via a funnel-shaped channel 109 with the treatment chamber 101 connected to the dry ice granules over a large angular range in the interior of the treatment drum 101 to be able to spin. This is in 2 indicated, with the protruding or over the surface protruding ridges and / or knobs 110 provided molding 102 within the treatment drum 101 , lying on and taken away by a driving shovel arranged therein 111 is arranged.

The supply of dry ice granules 11 in the interior of the case 105 the blower wheel 103 takes place via a narrow slot-shaped inlet opening 112 in the case 105 the blower wheel 103 , This is in 2 also indicated. The angle of an inlet channel 113 which is in the slot-shaped inlet opening 112 opens, to the central axis or axis of rotation 107 the blower wheel 103 is chosen so that a tangential flow of the impeller 103 or from its arms / shovels 106 with the dry ice granules is possible or without hitting the outer ends of the arms or blades 106 directly into one between the slot-shaped inlet opening 112 and the funnel-shaped outlet channel 109 arranged lock part 114 is sucked in because of in the lock part 114 resulting negative pressure with rotating impeller 103 , By such a tangential flow is a particularly good acceleration of the dry ice granules through the impeller 103 through in the direction of the funnel-shaped outlet channel 109 possible. The distance between the slot-shaped inlet opening 112 and the funnel-shaped outlet channel 109 is advantageous as short as possible, even before the abrasive processing of the piece and / or bulk material no unwanted heating of the dry ice granules 11 to risk inside the blast wheel housing. In particular, however, at the same time such a distance is selected that on the rotation of the centrifugal wheel 103 a very good acceleration of the dry ice granules 11 is possible. A particularly effective acceleration is achieved by acting on a negative pressure or generating a negative pressure in the lock part 114 when turning the blower wheel 103 generated. Over this can thus the Acceleration of the dry ice granules are carried out at a relatively high speed, with this in the treatment drum 101 is thrown in or blown. For wide-angle distribution of dry ice granules 11 in the interior of the treatment drum 101 inside is the funnel-shaped outlet channel 109 with the opposite the slot-shaped inlet opening 112 significantly larger outlet opening 115 from the outlet channel 109 intended.

To 3 is the means for accelerating the dry ice granules produced 11 in the form of an injection gun 104 educated. This acts on the molding 102 or its protruding burrs and nubs 110 with a mixture of cooled down air and the deburring material in the form of the dry ice granules 11 , Accordingly, in 3 on the one hand, the supply of dry ice granules 11 to the injection gun 104 indicated on the other hand, the supply of cooled air 116 , In the embodiment according to 3 cooled air is generated by the fact that air 117 in a compression device 118 compressed, in one of these downstream drying device 119 dried, in a pressure reducer 123 the pressure of the air diminished and the air in a cooling system 124 is cooled. On the one hand, the dry ice granules 11 about turning the blast wheel 103 and generating a negative pressure in the lock part 114 sucked in and with the cooled air 116 together on the burrs or pimples to be cut 110 of the molding 102 spin coated. Furthermore, however, it is also possible for the dry ice granules when passing through the cooled air 116 to suck in under the action of a negative pressure occurring or acting and to carry it with the air flow. The cooled air is through the nozzle-like injection gun 104 passed and through this together with the Entgratungsmaterial in the form of dry ice granules 11 on the burrs to be cut 110 of the molding 102 spun on. The injection gun 104 is in particular designed so that a negative pressure is generated in particular by the flowing through cooled air and is used for sucking the dry ice granules. This makes it possible, at the same time a short strong cooling and irradiation of the ridges or knobs to be separated 110 provided. The ridges or nubs to be separated embrittle when they are swept or irradiated or acted upon by the same with the cooled air and can, in the brittle state, be removed from the surface of the molded part 102 be subsequently rejected easily.

The molded part or piece or bulk material 102 can consist of a variety of materials, in particular a die-cast material, such as zinc die-cast, a sand casting Good, an injection-molded Good, a good elastomeric material, such as rubber, or polyurethane or from a plastic material or a good from a Metal, in particular non-ferrous metal such as aluminum, zinc, etc., be. The one in the device 1 formed dry ice block or ring 10 or the dry ice granules made therefrom 11 has due to the avoidance of the formation of carbon dioxide snow to such a hardness that all materials mentioned above are treated easily, so to be separated ridges, knobs, etc. from the respective surface of the deburred molding or piece and / or bulk material 102 can be knocked off. By means of the injection gun 104 together with the dry ice granules 11 accelerated and used to act on the burrs or nubs, etc. used cooled air or the blower wheel 103 to 2 used refrigerant, which is centrally in the blast wheel 103 is flowed in and through the arms or blades 106 the blower wheel 103 together with the dry ice granules 11 into the interior of the treatment chamber or treatment drum 101 for deburring the molded parts arranged therein 102 or of the pieces and / or bulk goods arranged therein, embrittlement of the burrs, knobs, etc. to be knocked off takes place without further supply of refrigerant to the interior of the treatment drum 101 , In both embodiments of the device for accelerating the dry ice granules produced 11 For slinging onto the piece and / or bulk material to be deburred, embrittlement of the protruding and to be separated ridges, knobs etc. in each case by applying the mixture to be deburred moldings or to be deburred piece and / or bulk material with a mixture of refrigerant or cooled Air and dry ice granules 11 respectively. This is very effective and therefore very beneficial. Depending on the piece and / or bulk to be deburred 102 can the grain size of the dry ice granules 11 be varied. Also depending on the respective bulk and / or general cargo for deburring either an injection gun, which can be operated automatically, ie mechanically, and / or manually, or a blast wheel can be used, optionally also a combination of both, if so the piece of material to be deburred, ie of ridges, knobs, etc., which are projecting on the surface, should prove to be advantageous for piece and / or bulk material.

In addition to the embodiments described above and shown in the embodiments of the use of dry ice granules for the treatment of piece and / or bulk can be formed numerous other, in particular any combination of the above features, each treating the piece and / or Bulk material is a deburring of the same and the dry ice granules a dry ice snow content of less than 5%, in particular of about 0% and for deburring the piece and / or bulk material in particular a blast wheel and / or an injection gun is used, advantageously for embrittlement of the surface of the piece and / or bulk material to be separated burrs, knobs, etc. with the dry ice granules cooled air and / or a refrigerant, such as nitrogen, is carried.

LIST OF REFERENCE NUMBERS

1

Device for producing dry ice

2

pressure vessel

3

Storage and expansion tank (N ₂ )

4

Reservoir (CO ₂ )

5

core unit

6

print Setup

7

cover element

8th

cover element

10

Dry ice block / ring

11

dry ice granules

12

Device for shredding

20

inner lumen

21

outer wall

22

inner tube

24

outer tube

26

coiled space

27

inlet port

28

outlet

30

supply

31

Valve

32

inlet port

40

supply

41

Valve

42

inlet port

50

coiled gear

51

inlet port

52

outlet

53

outside

101

treatment drum

102

Molding / piece or bulk material

103

blower

104

injection gun

105

casing

106

Arms / blades

107

central axis of rotation

108

outlet opening

109

funnel-shaped channel

110

Ridges / studs

111

entrainment scoop

112

slit-shaped inlet opening

113

inlet channel

114

lock part

115

outlet

116

cooled air

117

air

118

compression device

119

drying device

120

Inlet opening of 2

121

Outlet opening on the pressure vessel

122

Inside of 22

123

pressure reducer

124

cooling system

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 1891822 U1 [0002]
• DE 102011014327 A1 [0002]

Claims (12)

Use of dry ice granules ( 11 ) for treating piece goods and / or bulk goods ( 102 ), characterized in that the treatment is a deburring of the piece and / or bulk material ( 102 ) and the dry ice granules ( 11 ) has a dry ice snow content of less than 5%. Use according to claim 1, characterized in that the dry ice granules ( 11 ) by means of a blower wheel ( 103 ) and / or an injection gun ( 104 ) to be deburred piece and / or bulk material ( 102 ) is spun on. Use according to claim 1 or 2, characterized in that the piece or bulk material ( 102 ) Die casting, sand casting, injection molding material, in particular zinc die-cast material, and / or good from at least one metal, in particular non-ferrous metal, and / or at least one plastic, in particular elastomeric material or polyurethane. Dry ice granules ( 11 ), produced by means of a device ( 1 ) for producing a dry ice block or ring ( 10 ) with a dry ice snow content of less than 5% with subsequent comminution ( 12 ) of the resulting dry ice block or ring ( 10 ) to a dry ice granulate ( 11 ). Dry ice granules ( 11 ) according to claim 4 or use according to claim 1, 2 or 3, characterized in that the dry ice granules ( 11 ) has a hardness of more than 3 Mohs, in particular more than 5 Mohs, and / or a density of more than 1,600 kg / m ³ . Plant for producing dry ice granules ( 11 ) from a dry ice block or ring ( 10 ) comprising at least one device ( 12 ) for crushing the manufactured dry ice block or ring ( 10 ) to dry ice granules ( 11 ). Plant according to claim 6, characterized in that a device ( 1 ) for producing the dry ice block or ring ( 10 ) is provided, the at least one pressure vessel ( 2 ) for receiving liquid carbon dioxide and for preventing the formation of carbon dioxide snow at least one device ( 3 . 31 ) is provided, by means of which the pressure vessel ( 2 ) is filled or filled with a pressurized medium (N ₂ ) before filling the carbon dioxide, and at least one further device ( 4 . 41 ) is provided, by means of which the carbon dioxide in the pressure vessel ( 2 ) against the medium pressure and displacement of the medium (N ₂ ) from the pressure vessel ( 2 ) is filled or filled. Plant according to claim 6 or 7, characterized in that at least one device for deburring piece and / or bulk material ( 102 ) by means of dry ice granules ( 11 ), the device comprising at least one device ( 103 . 104 ) for accelerating, in particular at least one blast wheel ( 103 ) and / or at least one injection gun or part of an injection gun ( 104 ). Plant according to claim 8, characterized in that the device ( 103 ) for accelerating a central feeder ( 108 ) for refrigerant, in particular nitrogen. Installation according to one of claims 8 or 9, characterized in that the device ( 109 ) for accelerating at least one inlet opening ( 112 ) for introducing dry ice granules ( 11 ) and at least one outlet opening ( 115 ) for the discharge of dry ice granules ( 11 ), at least one lock ( 114 ) between the inlet opening ( 112 ) and the outlet opening ( 115 ) and at least one institution ( 103 ) for generating a negative pressure in the lock part, wherein the inlet opening ( 112 ) and the outlet opening ( 115 ) are arranged at a small distance from each other. Installation according to claim 10, characterized in that the inlet opening ( 112 ) is slot-shaped. Plant according to claim 10 or 11, characterized in that the at least one outlet opening ( 119 ) has a larger dimension than the at least one inlet opening ( 112 ), in particular a funnel-shaped channel ( 109 ) is trained.

Images