DE19736291A1 - Device for directing compressed air and liquid carbon dioxide to machine for cooling - Google Patents

Abstract

The compressed air and liquid carbon dioxide are supplied from sources by connecting hoses to a hose safety unit (7) such as a mechanically operated valve and from there through one or more connecting hoses (2-4) to the machine (1). With a slow or sudden escape of the liquid carbon dioxide from a first hose part (7) the supply of liquid carbon dioxide and where applicable also the supply of compressed air is interrupted. There is an Independent claim for the polishing or grinding machine.

Description

The invention relates to a device for conducting compressed air and liquid or supercritical carbon dioxide or nitrous oxide in one Connection hose from a source for the compressed air and a source for the liquid or supercritical carbon dioxide or nitrous oxide to one or several machine (s), preferably one or more machine (s) for Surface treatment. The invention further relates to a machine for grinding and / or polishing and on an arrangement for guiding Compressed air and liquid or supercritical carbon dioxide or Nitrous oxide.

Under the term "liquid or supercritical carbon dioxide or Nitrous oxide "here is liquid or supercritical carbon dioxide or liquid or supercritical nitrous oxide.

Liquid carbon dioxide has a temperature of approximately 194 K to approximately 304 K and a pressure of approx. 1 bar to approx. 74 bar. Supercritical carbon dioxide has one Temperature greater than approx. 304 K and a pressure greater than approx. 74 bar.

Nitrous oxide in liquid form has a temperature of approx. 184 K to approx. 310 K and a pressure of approx. 1 bar to approx. 73 bar and the supercritical Nitrous oxide is at a temperature greater than approx. 310 K and a pressure greater than approx. 73 bar.  

Under the term "warm liquid carbon dioxide or nitrous oxide" here carbon dioxide or nitrous oxide in liquid form at one temperature of greater than approx. 283 K (10 ° C), for example, has warm liquid carbon dioxide a temperature of about 283 K to about 304 K and a Pressure from approx. 44 to approx. 74 bar.

Machines operated with compressed air are used in many areas today. The compressed air required for this is usually located centrally at a specific location generated and one or more machines are connected via a hose system Compressed air supplied.

It is also known, in particular in the field of surface processing, such as for example grinding and polishing, the local area of engagement of the Cooling tool of the machine. It is known to use cooling Using a liquid gas, such as air, nitrogen or carbon dioxide to make.

From DE 39 10 590 A1 a polishing machine is known, which one Polishing disc and a cold gas supply for cooling the to be polished or Grinding surface comprises, the cold gas supply preferably in one Gas outlet, which is arranged in the axis of rotation of the polishing disc, opens out. The device is preferably operated with nitrogen as the cold gas, which is in liquid Mold stored, evaporated and fed to the gas outlet via the cold gas supply becomes. To an optimal operating temperature of the cold gas, which is essentially depends on the material properties of the surface to be treated guarantee, the nitrogen must be heated at a complex temperature. It is also known to operate such a device with carbon dioxide as a cold gas, the when liquid carbon dioxide is released, a temperature of -78 ° C (195 K). This temperature is for the operation of such polishing machines advantageous, since they usually exactly meet the requirements for cooling requirements becomes.  

From a not yet published patent application by the applicant a machine for polishing and / or grinding with a relative movement known to the workpiece executing machining tool at the processing tool means for supplying liquid or Supercritical carbon dioxide are assigned and where the means of supply of liquid or supercritical carbon dioxide a valve for regulating the Flow rate of carbon dioxide with an expansion nozzle for the liquid or include supercritical carbon dioxide and in which the valve within the Machine is arranged.

The invention has for its object a device, an arrangement and Means to create a particularly used for cooling purposes liquid or supercritical carbon dioxide or nitrous oxide relative safely from a source of this liquid or supercritical carbon dioxide or nitrous oxide to a preferably operated with compressed air Machine.

The object is achieved according to the invention by a device with specified features solved and further by a machine for grinding and / or polishing according to claim 23 and an arrangement for conducting Compressed air and liquid or supercritical carbon dioxide or Nitrous oxide dissolved according to claims 24 and 25.

Advantageous developments of the invention are in the subclaims specified.

The term "hose" or "hose part" is not here a hose in the narrow sense. The device according to the invention also includes Pipes and pipe-like connections between the source for the compressed air and the liquid or supercritical carbon dioxide or nitrous oxide and the with compressed air and using the liquid or supercritical  Carbon dioxide or nitrous oxide operated tool. For reasons the easier handling of the tool are hoses with one certain flexibility preferred.

According to the invention, it is provided that the material (s) for the second, outer tube part a plastic and / or an elastomer, preferably a Composite consisting of an inner layer (soul) and an outer ceiling synthetic rubber and one arranged between the soul and the outer ceiling Yarn braid is used as a pressure carrier. The first, inner tube part is manufactured according to the invention from a plastic and / or an elastomer, preferably a composite consisting of an inner layer made of polyamide, a print carrier made of highly tear-resistant synthetic fiber and an outer layer Polyamide or polyurethane is used and the print medium between Inner layer and outer layer is arranged. The inside diameter of the The first, inner tube part is particularly preferably 2 to 2.5 mm and the Outside diameter 4.5 to 6 mm for the first, inner tube part. Through the Use of such hose parts for the connecting hose is on the one hand a relatively good flexibility of the connecting hose ensured and on the the other side is a safe conduction of compressed air in the outer hose part and the liquid or supercritical carbon dioxide or nitrous oxide guaranteed in the inner tube part.

According to the invention, preferably warm liquid carbon dioxide or Nitrous oxide, but particularly preferably warm liquid carbon dioxide a temperature of approx. 284 K to approx. 304 K and with a pressure of approx. 44 bar up to approx. 74 bar. When using supercritical Carbon dioxide or nitrous oxide is the range below about 100 bar for the supercritical gas is particularly preferred. However, the invention is not based on the mentioned gases limited. Rather, any gas or gas mixture used physical properties similar to those of carbon dioxide or has nitrous oxide and the requirements of use,  in particular the use for cooling purposes of one to be processed Surface, fulfilled.

The inventive device will now be based on three figures (Fig. 1, Fig. 2 and Fig. 3) explained in greater detail.

Fig. 1, the device according to the invention shows an example for safe guidance of compressed air into an outer tube portion and of liquid or supercritical carbon dioxide or nitrous oxide in an inner hose part.

Fig. 2 shows an example of various options for the design of the connecting hose.

In Fig. 3, a flange for connecting the connecting hose to the machine and / or to the hose securing unit is shown as an example.

In the device shown in FIG. 1, the liquid or supercritical carbon dioxide or nitrous oxide for cooling purposes and compressed air for driving the machine is fed to a machine for grinding and / or polishing ( 1 ) via a connecting hose ( 2 ). The connecting hose ( 2 ) has two hose parts ( 3 , 4 ) lying coaxially one inside the other, the liquid or supercritical carbon dioxide or nitrous oxide being conducted in a first, inner hose part ( 3 ) and the compressed air being conducted in a second, outer hose part ( 4 ) becomes. The connecting hose ( 2 ) is connected to the machine via a flange ( 5 ) and to a hose securing unit ( 7 ) via a flange ( 6 ). The hose safety unit ( 7 ) has a break safety device ( 8 ) which, for example with the aid of a valve (not shown here), supplies the supply when the liquid or supercritical carbon dioxide or nitrous oxide escapes slowly or suddenly from the first, inner hose part ( 3 ) of liquid or supercritical carbon dioxide or nitrous oxide and, if necessary, additionally the supply of compressed air is interrupted. This interruption occurs when a certain limit value for the flow of compressed air is exceeded in the form of the connecting hose ( 2 ) shown here or when a certain pressure increase in a third hose part (not shown here) of a connecting hose ( 8 ) connected to the hose securing unit ( 7 ). An embodiment not shown here, in which the connecting hose ( 8 ) has at least three hose parts, the liquid or supercritical carbon dioxide or nitrous oxide being conducted in at least one first hose part and compressed air being conducted in at least one second hose part, and in which the first hose part and the second hose part are arranged side by side coaxially within the third hose part. The hose securing unit ( 7 ) also has a non-return flap ( 9 ) which is connected to a connection piece ( 10 ) via which the compressed air is supplied from the source for the compressed air ( 10 ) via a line ( 11 ). In the event of an increase in the pressure in the connecting hose ( 2 ) above the pressure of the compressed air supplied to the hose securing unit ( 7 ), the supply of compressed air is interrupted. The liquid or supercritical carbon dioxide or nitrous oxide is stored in a tank ( 13 ) or in pressurized gas cylinders (not shown here) and fed to the hose securing unit ( 7 ) via a line ( 14 ) and a connection piece ( 15 ). On the nozzle ( 15 ) a rupture disc ( 16 ) is arranged, which is connected to the tank ( 13 ) or the line ( 14 ) of the liquid or supercritical carbon dioxide or nitrous oxide, and in the event of an increase in the pressure of the supplied liquid or supercritical carbon dioxide or nitrous oxide over a certain pressure the supply in the connecting hose ( 2 ) is interrupted. The rupture disc ( 16 ) is preferably designed so that the supply in the connecting hose ( 2 ) is interrupted at a pressure of approximately 100 bar.

Fig. 2 shows embodiments of the connecting hose with two hose parts ( Fig. 2.1), three hose parts ( Fig. 2.2), 6 hose parts ( Fig. 2.3) and a further variant with three hose parts ( Fig. 2.4).

The connecting hose shown in Fig.2.1 has two coaxial hose parts ( 3 , 4 ), the liquid or supercritical carbon dioxide or nitrous oxide being conducted in the first, inner hose part ( 3 ) and compressed air in the second, outer hose part ( 4 ) is directed. In the connecting tube in Fig. 2.2 are three tube parts (3, 4, 17), wherein the first tube member (3), in which the liquid or supercritical carbon dioxide or nitrous oxide is passed and the second tubular part (4), guided in which compressed air is arranged side by side coaxially within a third tube part ( 17 ). In Fig. 2.3 a of FIG. 2.2 corresponding connecting tube (2) is shown, in which case a first tube part (3) and four second tube parts (4 a, 4 b, 4 c, 4 d) coaxially within a third tube part (17) are arranged. The connecting hose ( 2 ) shown in Fig. 2.4 is a variant of the connecting hose ( 2 ) shown in Fig. 2.2. Here the three hose parts ( 3 , 4 , 17 ) are arranged so that the first hose part ( 3 ), in which the liquid or supercritical carbon dioxide or dinitrogen monoxide is conducted, and the second hose part ( 4 ), in which compressed air is conducted, lie side by side , wherein the first hose part ( 3 ) is arranged coaxially within a third hose part ( 17 ). It is possible to make the connecting hose ( 2 ) coiled, as shown here in Fig.2.4 . This has the advantage that the connecting hose ( 2 ) is also elastic in the longitudinal direction, that is to say it can be stretched without great stresses which can impair the guidance of the machine ( 1 ).

The flange ( 18 ) shown in Fig. 3.1 is used to connect the connecting hose ( 2 ) to the machine ( 1 ) and / or to the hose securing unit ( 7 ). The connecting hose ( 2 ) consists in this case of two hose parts ( 3 , 4 ) lying coaxially one inside the other, the liquid or supercritical carbon dioxide or nitrous oxide being conducted in the first, inner hose part ( 3 ) and in the second, outer hose part ( 4 ) Compressed air is passed. The connecting hose is arranged on the flange ( 18 ), which consists of two coaxial pipe sections ( 20 , 21 ) at the end of the connecting hose and a perforated disc ( 22 ) on the machine or hose securing unit side and which means ( 23 , 24 , 25 , 26 ) to arrange and seal the flange ( 18 ) on the machine ( 1 ) or hose securing unit ( 7 ). The first, inner tube section ( 20 ) connects to the first, inner tube part ( 3 ). The outer diameter of the first, inner tube section ( 20 ) is therefore dimensioned such that the inner jacket surface of the first, inner tube part ( 3 ) is in positive contact with the outer jacket surface of this first, inner tube section ( 20 ). The connection to the compressed air is made possible with the aid of the second, outer tube section ( 21 ), the outer diameter of the second, outer tube section ( 21 ) being dimensioned such that the inner lateral surface of the second, outer hose part ( 4 ) is in positive contact with the outer lateral surface this second, outer tube section ( 21 ). The liquid or supercritical carbon dioxide or nitrous oxide and the compressed air are conducted to the perforated disc ( 22 ) through the two pipe sections ( 20 , 21 ) lying coaxially one inside the other. The perforated disc ( 22 ) has an opening ( 27 ) for the liquid or supercritical carbon dioxide or nitrous oxide and openings ( 28 ), preferably four openings, for the compressed air. The openings ( 28 ) are arranged centrally around the central opening ( 27 ) for the liquid or supercritical carbon dioxide or nitrous oxide and guide the compressed air at an included angle (a) of 15 to 45, based on the longitudinal axis of the flange ( 18 ) , to the machine ( 1 ) or the hose securing unit ( 7 ). The flange ( 18 ) is fastened to the machine ( 1 ) or to the hose securing unit ( 7 ) with the aid of a screw connection. For this purpose, openings ( 23 ) are arranged in the perforated disc ( 22 ) through which the screws or stud bolts are guided (not shown here). Four of these openings ( 23 ) are preferably arranged centrally around the central opening ( 27 ) for the liquid or supercritical carbon dioxide or nitrous oxide. It is also provided that the flange ( 18 ) is attached to the machine ( 1 ) or to the hose securing unit ( 7 ) by means of a union nut (not shown here) via the perforated disc ( 22 ). To seal the flange ( 18 ) and thus the connection between the connecting hose ( 2 ) and the machine ( 1 ) or hose securing unit ( 7 ), the perforated disc ( 22 ) has a pipe section-like connector ( 26 ) arranged on the machine end or on the hose securing unit end. on the outer lateral surface elastic sealing material ( 25 ) is arranged. In addition, elastic sealing material ( 24 ) is arranged on the perforated disc ( 22 ) on its end face on the machine side or hose securing unit side.

Claims (25)

1. Device for directing compressed air and liquid or supercritical Carbon dioxide or nitrous oxide in a connecting hose from a source for the compressed air and a source for the liquid or supercritical carbon dioxide or nitrous oxide to one or more Machine (s), preferably one or more machine (s) for Surface treatment, where the compressed air and the liquid or supercritical carbon dioxide or Nitrous oxide is fed to a hose securing unit and by the hose securing unit via one or more Connection hose / hoses, the at least two Has / have hose parts, wherein in at least a first Hose part the liquid or supercritical carbon dioxide or Nitrous oxide is passed and in at least a second Hose part of compressed air is passed and at which the Hose securing unit means are assigned, whereby at a slow or sudden escape of the liquid or supercritical Carbon dioxide or nitrous oxide from a first hose part Liquid or supercritical carbon dioxide or Nitrous oxide and, if necessary, additionally the supply of compressed air is interrupted. 2. Device according to claim 1, where the connecting hose (s) have at least three Has / have hose parts, wherein in at least a first Hose part the liquid or supercritical carbon dioxide or Nitrous oxide is passed and in at least a second Hose part of compressed air is conducted and in which the first hose part and the second hose part is arranged within a third hose part are.   3. Device according to claim 1 or 2, in which the supply of liquid or supercritical carbon dioxide or Nitrous oxide and, if necessary, additionally the supply of compressed air is interrupted at one compared to the normal conditions at least ten times the pressure and / or flow rate of the Compressed air and / or liquid or supercritical carbon dioxide or Nitrous oxide. 4. Device according to one of claims 1 to 3, where the connecting hose (s) at least has / have two coaxially nested hose parts, wherein in the liquid or at least a first, inner tube part supercritical carbon dioxide or nitrous oxide is passed and in At least a second, outer hose part of compressed air is passed. 5. The device according to claim 4, in which the first, inner tube part has an inner diameter of 1 to 6 mm and the second, outer tube part an inner diameter of 6 to 20 mm. 6. Device according to one of claims 4 or 5, in which a plastic is used as the material (s) for the first, inner tube part and / or an elastomer is / are used and as material (s) for the second, outer tube part a plastic and / or an elastomer will be used. 7. Device according to one of claims 4 to 6, in which the second, outer tube part consists of several, preferably 1 to 4 individual hose parts, which are concentric around the first inner hose part are arranged.   8. Device according to one of claims 1 to 7, in which the supply of liquid or supercritical carbon dioxide or Nitrous oxide and, if necessary, additionally the supply of compressed air is interrupted at a pressure in the range of 10 to 30 bar second hose section through which compressed air flows. 9. Device according to one of claims 1 to 8, in which the hose securing unit has at least one valve, one Check valve and a break protection are assigned, the Break protection in the event of a slow or sudden escape of the liquid or supercritical carbon dioxide or nitrous oxide a first tube part the supply of the liquid or supercritical Carbon dioxide or nitrous oxide and, if necessary, additionally Compressed air supply at a certain flow limit the hose securing unit interrupts by closing a valve, which in connection with the source or the feed line of the liquid or supercritical carbon dioxide or nitrous oxide and where the Non-return valve is connected to the source or the feed line of the Compressed air and in the event of an increase in pressure in / in Connection hose / connection hoses on the pressure of the Hose securing unit supplied compressed air the supply of compressed air interrupts. 10. The device according to claim 9, in which a rupture disc is also arranged, which is connected with the source or the supply line of the liquid or supercritical Carbon dioxide or nitrous oxide and what in the case of a Increase the pressure of the supplied liquid or supercritical Carbon dioxide or nitrous oxide over a certain pressure Feed in the connecting hose (s) interrupted becomes.   11. The device according to claim 10, in which the rupture disc is designed so that the feed into the Connection hose / connection hoses is interrupted at a Pressure of approx. 100 bar. 12. The device according to one of claims 9 to 11, where the hose securing unit is a mechanically operated valve The second part (s) through which compressed air flows the connecting hose (s) is connected with an element made of elastic material or a has elastic storage, whereby the valve at a certain Limit for the pressure in the first Connection hose / connecting hoses, which by a slow or sudden escape of liquid or supercritical carbon dioxide or nitrous oxide is caused from a first tube part that Liquid or supercritical carbon dioxide or Nitrous oxide and, if necessary, additionally the supply of compressed air interrupts. 13. The device according to one of claims 3 to 12, where the connection hose (s) are connected to one Flange is / are, which consists of a perforated disc and two coaxially nested pipe sections on connecting hose end with a first, inner tube section and a second, outer tube section and which means has to the flange on the machine and / or the To arrange and seal the hose securing unit, the Perforated disc at least one opening for the liquid or supercritical Carbon dioxide or nitrous oxide and at least one opening for the Compressed air and wherein the outer diameter of the first, inner Pipe section is dimensioned so that the inner surface of the first, inner tube part, in which the liquid or supercritical  Carbon dioxide or nitrous oxide is passed in a positive manner Contact with the outer surface of this first, inner tube section and wherein the outer diameter of the second, outer tube section is dimensioned such that the inner lateral surface of the second, outer Part of the hose in which the compressed air is conducted in a form-fitting manner Contact with the outer surface of this second, outer Pipe section is. 14. The apparatus according to claim 13, where the flange is a central, centrally located opening for the liquid or supercritical carbon dioxide or nitrous oxide and four Has openings for the compressed air, which is centered around the central Opening for the liquid or supercritical carbon dioxide or Nitrous oxide are arranged around and which in one included angle (a) of 15 to 45 °, based on the longitudinal axis of the flange are arranged. 15. The apparatus of claim 13 or 14, wherein the flange one at machine-side and / or hose securing unit-side end arranged pipe section-like connecting piece, on the outer The outer surface of the elastic sealing material is arranged and in which the Flange on the end face additionally has elastic sealing material. 16. The device according to one of claims 1 to 15, where the liquid or supercritical carbon dioxide or Nitrous oxide has a pressure in / in the first hose part (s) of 40 to 80 bar. 17. The device according to one of claims 1 to 16, at which the source of the liquid or supercritical carbon dioxide or Nitrous oxide is a source of liquid carbon dioxide, preferably warm liquid carbon dioxide, is.   18. Device according to one of claims 1 to 17, in the case of liquid or supercritical carbon dioxide or nitrous oxide is supplied from a pipeline or in a low pressure tank, a Medium pressure tank or in a bottle, with between Low pressure tank and hose securing unit one Pressure increasing unit is arranged. 19. Device according to one of claims 1 to 18, where the machine is a machine for grinding and / or polishing one executing a relative movement with respect to the workpiece Editing tool. 20. The apparatus according to claim 19, in the machine means for supplying liquid or supercritical Carbon dioxide or nitrous oxide are associated with an exit for the liquid or supercritical carbon dioxide or nitrous oxide include which is in the immediate vicinity of the machining tool is arranged. 21. The apparatus according to claim 20, in which the means for supplying liquid or supercritical carbon dioxide or nitrous oxide in the axis of rotation of a rotating or oscillating machining tool are arranged. 22. The apparatus according to claim 21, in which the means a valve for regulating the flow rate of the liquid or supercritical carbon dioxide or nitrous oxide with an expansion nozzle for the liquid or supercritical carbon dioxide or nitrous oxide, with the valve inside the machine is arranged.   23. Machine for grinding and / or polishing in the machine means for supplying liquid or supercritical Carbon dioxide or nitrous oxide and a hose safety device are assigned, causing a slow or sudden escape of liquid or supercritical carbon dioxide or nitrous oxide from a connecting hose between the hose securing unit and Machine supplying liquid or supercritical carbon dioxide or Nitrous oxide is interrupted. 24. Arrangement for directing compressed air and liquid or supercritical Carbon dioxide or nitrous oxide from a source of compressed air and a source of the liquid or supercritical carbon dioxide or Nitrous oxide to a machine using a device, in particular according to claim 1, with compressed air and liquid or supercritical carbon dioxide or Nitrous oxide is fed to a hose securing unit and then from the hose securing unit via a Connection hose is fed to a machine. 25. Arrangement for directing compressed air and liquid or supercritical Carbon dioxide or nitrous oxide from a source of compressed air and a source of the liquid or supercritical carbon dioxide or Nitrous oxide to two or more, preferably two to ten Machines with the aid of a device, in particular according to claim 1, with compressed air and liquid or supercritical carbon dioxide or Nitrous oxide is fed to a hose securing unit and then from the hose securing unit via two or more Connection hoses are fed to the machines.