EP3279596B1 - Instrument bracket and method for liquid-free instrument cooling and system for liquid-free monitoring of the interior of high temperature systems - Google Patents

Description

The invention relates to an instrument holder and a method for liquid-free instrument cooling, in particular for use in the high temperature range, as well as a system or an arrangement for liquid-free interior monitoring of high-temperature systems.

US6069652 discloses an apparatus for monitoring industrial processes, and more particularly relates to a video camera and associated therewith a thermal protection device for viewing the interior of a heated chamber.

For the monitoring and observation of the interior of high-temperature systems, such as in particular industrial furnaces, burners or thermal process rooms at operating temperatures of more than 900 ° C have to make special demands on the temperature resistance of the monitoring instruments. Thus, it is necessary that sensors and cameras, which are usually fixed to lances fixed end face in the relevant high temperature range or arranged in the area concerned, must be cooled so as not to be damaged. So far, the cooling of such lances is realized with a multi-walled, liquid-cooled protective housing having a frontal view opening for a monitoring or observation instrument. However, it has been found that the acceptance for the use of liquid-cooled, in particular water-cooled, systems is low, since such systems pose a risk of water entering the high-temperature system, which can cause damage. There is therefore a need for a liquid-free cooling of instruments for monitoring and monitoring the interior of High temperature systems, in particular ovens, burners and thermal process rooms.

It is therefore an object of the present invention to propose ways for liquid-free cooling of instruments for monitoring and observation of the interior of high temperature systems.

The object is achieved by an instrument holder for liquid-free instrument cooling with the features according to claim 1, a system for liquid-free interior monitoring of high-temperature systems according to claim 8 and a method for liquid-free instrument cooling according to claim 11. Further developments are specified in the respective dependent claims.

The instrument holder according to the invention for liquid-free instrument cooling comprises a protective housing which is at least double-walled, an inlet opening for cooling gas, at least one flow channel for cooling gas and at least one outlet opening for cooling gas. Furthermore, the instrument holder according to the invention comprises an instrument housing, which can be arranged in a flow channel for cooling gas, with an inlet opening for a flushing gas, a flushing gas flow channel, at least one outlet opening for flushing gas, an opening for an instrument and fastening means for fastening an instrument in the instrument housing. Through the flow channel for a cooling gas, it is possible to dissipate the heat input when used in the high-temperature system with a flow of cooling gas, without a liquid cooling is required. Advantageously, the instrument housing, in which instruments, such as cameras or sensors for monitoring and monitoring of the interior of high-temperature systems can be attached, arranged in the flow channel for cooling gas, so that a cooling gas flow can flow around the instrument housing, thereby displacing ambient heat.

For the purposes of the invention, high-temperature systems are to be understood to mean furnaces, such as glass melting furnaces or aluminum melting furnaces, burners or thermal process rooms, whose internal temperatures or operating temperatures are above 900 ° C. This is not to exclude that the instrument holder according to the invention can be used advantageously even at lower temperatures for cooling instruments for monitoring and observation of the interior of high-temperature systems.

The term instrument is in the context of the invention for a variety of devices that can be used to monitor or monitor the interior of high-temperature systems and thereby need to be cooled.

According to an advantageous embodiment of the instrument holder according to the invention, the protective housing may be formed with an outer tube and at least one inner tube. In this case, the outer and the inner tube may be arranged so that between the outer tube and the at least one inner tube, a flow channel for cooling gas is formed. In this production-technically advantageous embodiment, the double-walled protective housing is formed by two tubes arranged inside one another, wherein the outer tube can project beyond an end face of the at least one inner tube at the outlet opening for cooling gas. As a result, the outer tube forms an extended shield against the ambient heat when used in the high-temperature system. It can also be provided that the protective housing is formed with a plurality of inner tubes, each having smaller outer diameter and therefore can be arranged so that between each of them a flow channel for cooling gas is formed. It may further be provided that an inner tube projects beyond the end face of an inner tube with a smaller outer diameter in order to achieve a protective effect against the ambient heat.

Basically, the shape of the protective housing is not limited to a round shape. Other shapes may also be provided which are adapted, for example, to an opening in a wall of a high-temperature system.

To protect against radiant heat, the instrument housing is further arranged inside the protective housing, so that the protective housing projects beyond the instrument housing, without the view opening for an instrument is covered. Preferably, the position of the instrument housing in the protective housing can be changed to change the field of view for an instrument for observing the interior. However, a change in the position of the instrument housing can also be advantageous to protect the instrument from excessive thermal stress. In this case, the instrument case can be positioned deeper in the protective case.

According to a further advantageous embodiment of the instrument holder according to the invention, it may be provided that a flow channel for cooling gas is formed between the instrument housing and the protective housing, so that the instrument housing can be completely surrounded by a flow of cooling gas. It may further be provided that an inner wall of the protective housing has at least one opening corresponding to a flow channel for cooling gas. Such an opening formed in the inner tube of the protective housing ensures a supply of cooling gas for the further flow channel formed between the instrument housing and the protective housing. Advantageously, a plurality of flow channels for cooling gas can thereby be provided without requiring further inlet openings for cooling gas. This also has a constructive advantage, since the instrument holder can be made less bulky. According to the invention, the outlet opening for cooling gas, the outlet opening for purge gas and the viewing opening for an instrument are arranged on a high-temperature side of the instrument holder. In this embodiment, all outlet openings for cooling gas and purge gas are arranged in the direction of a arranged in the instrument housing instrument, so that the gases for cooling and flushing are used in the high-temperature system in the interior of the high-temperature system. Advantageously, the inside outgoing gas is used to allow an improved view in the direction of view for an instrument.

For applications in which an excessive gas input into the interior of the high-temperature system is undesirable, provision may be made for the outlet opening for cooling gas to be arranged on a side of the instrument holder facing away from the high temperature. Conveniently, the flow channel for cooling gas may be formed so that spent cooling gas is discharged to the environment on a low temperature side or provided for further use.

According to a further advantageous development of the instrument holder according to the invention, several of the outlet openings for purge gas can be arranged around the viewing opening for an instrument for monitoring the interior. Conveniently, the inlet opening for cooling gas, the inlet opening for purge gas and at least one connection for signaling or electrical connection with an instrument on a side remote from the high temperature side of the instrument holder can be arranged.

The protective housing is expediently formed from a temperature-resistant material. Ceramics, composite materials or metal alloys which have a high melting point are conceivable. Stainless steel alloys have proved to be particularly advantageous. That's how it works Protective housing preferably be formed of a stainless steel alloy. Particularly preferably, the protective housing may be formed of the stainless steel alloy of grade 1.4301.

The instrument housing may also be formed of a temperature-resistant stainless steel alloy. In order to achieve a weight reduction of the instrument holder parts of the instrument housing may be formed of aluminum. Preferably, parts of the attachment means for mounting the instrument in the instrument housing are made of aluminum. Furthermore, it can also be provided that the instrument housing has a guide for instruments, in particular a camera guide, with which a camera can be moved within the instrument housing.

For fixing and / or fixing the instrument holder in or on a wall opening of a high-temperature system, the instrument holder may have a fastening device. In this case, the fastening device may comprise a guide in which the protective housing is guided displaceably. Through the guide, the penetration depth of the protective housing can be influenced in the high-temperature system. Advantageously, the protective housing can be slid so that the penetration depth into the interior of a high-temperature system can be varied in order to minimize the heat input due to thermal radiation. The fastening device may be designed so that it can be screwed to the wall of a high-temperature system.

For the determination of the temperature distribution in / on the protective housing and in / on the instrument housing thermometers or temperature sensors can be arranged at different positions in or on the instrument housing. The data provided by the thermometers or temperature sensors can be used to control the gas flows for cooling and / or flushing.

The invention further comprises a system for liquid-free interior monitoring of high-temperature systems with an instrument holder according to the preceding description.

The system of the invention includes an instrument held by the instrument holder, a controller for processing signals from the instrument, and a supply means for providing a gas flow to the instrument holder. An instrument is expediently to be understood as a device or a measuring device which can detect signals of physical and / or chemical processes. Preferably, a camera, a pyrometer or a combination of camera and pyrometer can be used as an instrument.

Preferably, the supply device may have a pressure regulator, with which the pressure of the gas flow is preferably adjustable in the range of 0.1 bar to 8.5 bar. Furthermore, it can be provided that the supply device has a flow meter, with which the volume flow of the gas stream can be determined. Conveniently, the pressure regulator and the flow meter can be used for an appropriate adjustment of the required for cooling the camera and the instrument holder volume flow of a gas. Furthermore, provision can be made for the supply device to be set up for automatic control and / or regulation of the gas flow, the supply device accessing, for example, temperature data provided by temperature sensors of the instrument holder.

According to the embodiment of the instrument holder, the supply device can provide a cooling gas flow and a purge gas flow to the instrument holder, wherein the cooling gas flow and the purge gas flow are independently controllable.

For the provision of the gas stream for cooling and / or flushing, the supply device can be connected to a gas source or have a device which provides a gas volume, such as bottled gas. In a particularly simple embodiment of the system according to the invention ambient air is used as the gas source, so that the supply device can be connected to an existing compressed air network or compressed air is provided via a compressor, which may be part of the supply device. It is also conceivable that required for cooling and / or flushing gas flows are provided with a fan.

However, it can also be provided that different gases, such as inert gases, are used for cooling and rinsing. Accordingly, the supply device can have multiple connections for gas sources. Also conceivable is a receiving device for gas cylinders in a housing of the supply device.

In order to minimize the risk of introducing liquid into a high-temperature system, the supply device can have a liquid separator or water separator, with which liquid / water can be separated from the gases used for cooling and / or rinsing.

According to an advantageous development of the system according to the invention, the control device for processing camera signals and the supply device for providing a gas flow can be arranged in a common housing.

For connecting the supply device to the instrument holder, heat-resistant hose lines can be used, which are fastened with screwed-on screw connections.

Furthermore, the invention comprises a method for liquid-free instrument cooling with a previously described instrument holder or a system for liquid-free interior monitoring of high-temperature systems, wherein for cooling an instrument held by the instrument held a volume flow for a cooling gas and / or a flow rate for a purge gas in response to a temperature the instrument, a temperature of the instrument holder and / or an ambient temperature of the instrument holder is provided to the instrument holder.

According to an advantageous embodiment of the method according to the invention, the volume flow for a cooling gas and / or for a purge gas in dependence on the temperature of the instrument, a temperature of the instrument holder and / or an ambient temperature of the instrument holder is controlled. In this case, temperature data provided by the temperature sensors of the instrument holder can be taken into account.

According to an advantageous embodiment of the method according to the invention can be used as the cooling gas and / or purge gas air. For certain applications, however, it can also be provided that an inert gas, such as nitrogen or a noble gas, is used as the cooling gas and / or purge gas.

Preferably, a cooling gas pressure and / or a purge gas pressure in the range of 0.1 bar to 8.5 bar can be adjusted. Particularly preferably, a purge gas pressure of 1 bar and a cooling gas pressure of at least 0.5 bar are set.

According to a further advantageous embodiment of the method according to the invention, a total volume flow for cooling gas and purge gas of at least 0.6 m ³ / min can be set. Usually this is Temperature of the supplied cooling gas 20 ° C to 30 ° C. Advantageously, with an instantaneous flow of 0.6 m ³ / min through the instrument holder at an ambient temperature in the high temperature system of 1700 ° C, a permanent cooling of an instrument held by the instrument holder instrument can be achieved to a temperature not exceeding 55 ° C.

Fig. 1:

eine schematisch perspektivische Schnittdarstellung eines Ausführungsbeispiels einer Instrumentenhalterung für eine flüssigkeitsfreie Kühlung mit Befestigungsvorrichtung für den Einsatz in einem Hochtemperatursystem

Fig. 2:

eine weitere Schnittdarstellung eines Ausführungsbeispiels einer Instrumentenhalterung zur flüssigkeitsfreien Instrumentenkühlung

Further details, features and advantages of embodiments of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. Show it:

Fig. 1:

a schematic perspective sectional view of an embodiment of an instrument holder for a liquid-free cooling with fastening device for use in a high-temperature system

Fig. 2:

a further sectional view of an embodiment of an instrument holder for liquid-free instrument cooling

Recurring features are identified in the figures with the same reference numerals.

The FIG. 1 shows a schematic perspective sectional view of an embodiment of an instrument holder 1 with fastening device 11 for use in a high-temperature system.

In the example shown here, the right side A of the instrument holder 1 is the high-temperature side, which is referred to as the high-temperature side. The side B facing away from the high-temperature side may also be referred to as a low-temperature side.

The instrument holder 1 has a reference numeral 2 characterized double-walled protective housing, which is formed with an outer stainless steel tube 2.1 and an inner stainless steel tube 2.2. On the ambient temperature side B, the protective housing 2 has an inlet opening 3 for cooling gas. Between the outer stainless steel tube 2.1 and the inner stainless steel tube 2.2, a flow channel 4.1 is formed, which has an outlet opening for cooling gas 5.1 on the high-temperature side. Furthermore, the protective housing 2 has a perforation 3.1 corresponding to the flow channel 4.1 in the stainless steel tube 2.2. In this case, the opening 3.1 is formed coaxially to the central axis of the inlet opening 3, so that introduced into the inlet opening 3 cooling gas can pass through the opening 3.1 in the marked with the reference numeral 4.2 flow channel. The flow channel 4.2 has an outlet opening 5.2 for cooling gas, through which a cooling gas can be discharged into the high-temperature region into the interior of a high-temperature system. Consequently, a cooling gas introduced into the inlet opening 3 can flow through the flow channels 4.1 and 4.2 and thereby discharge a heat input acting on the protective housing 2.

In the present example, the outer stainless steel tube 2.1 longer than the inner stainless steel tube 2.2 is formed so that the outer stainless steel tube 2.1 the front side of the inner stainless steel tube 2.2 projects beyond the outlet 5.1.

Reference numeral 6 denotes an instrument housing which is arranged in the flow channel 4.2 of the protective housing 2. The instrument case 6 has an inlet port 7 for a purge gas, a purge gas flow passage 8, and a plurality of outlet ports (not shown) arranged in a circular shape formed in the end surface of the instrument case 6 on the high-temperature side. Also in the end face of the instrument housing 6, a look-out opening 9 for an instrument (not shown) for observing and monitoring the interior of a high-temperature system is formed. Furthermore, the instrument housing 6 fastening means for attachment of an instrument, which in the present example is an aluminum guide bar 10 intended for mounting a camera (not shown). Not shown is a connection option for signaling and / or electrical connection of a camera. Preferably, such a connection possibility is provided on the low-temperature side at one end of the instrument housing 6.

According to the present embodiment, the instrument case 6 is movably disposed in the protective case 2, so that the position of the instrument case 6 can be varied. Thus, the position of the instrument housing 6 can be changed accordingly at particularly high temperatures in order to better exploit the protective shield effect of the protective housing 2.

The reference numeral 11 denotes a fixing device for fixing the instrument holder 1 to a wall opening of a high-temperature system (not shown). In the present example, the fastening device is a steel plate with a guide 12 for holding and guiding the protective housing 2. The guide 12 allows a change of the insertion position of the protective housing 2, so that the positioning of the instrument holder 1 in the wall of a high-temperature system can be adjusted can. Furthermore, the fastening device 11 holes 11.1, by means of which the fastening device 11 by means of screws or bolts to a wall opening of a high-temperature system (not shown) can be attached.

The FIG. 2 shows a further sectional view of an embodiment of an instrument holder 1 for use in a high-temperature system. Unlike the in FIG. 1 As shown, the instrument holder 1 is shown without the fixing device 11. The shown instrument holder 1 has in the present example a total length of 453 mm and a diameter of 60 mm (measured on the outer diameter of the protective housing 2). The outer stainless steel tube 2.1 of the protective housing 2 is 310 mm long and has a wall thickness of 1.5 mm, so that results because of the outer diameter of 60 mm, an inner diameter of 57 mm. The inlet opening for cooling gas 3 is arranged at a distance of 29.35 mm from the right edge of the instrument holder 1 and has an opening diameter of 18 mm. The inner stainless steel tube 2.2 is formed with 300 mm shorter than the outer stainless steel tube 2.1 and has an outer diameter of 45 mm with a wall thickness of 1.5 mm. Furthermore, the inner stainless steel tube 2.2 two openings 3.1, which correspond to the inlet opening 3 in terms of their position and dimensions. The instrument housing 6 arranged in the flow channel 4.1 is 315 mm long and has a diameter of 22 mm. The left side end face of the instrument case 6, which faces the inside of the high temperature system, has a thickness of 2 mm. The diameter of the formed in the end face of the instrument housing 6 view opening 9 is 6 mm. The reduction in cross-section of the flow channel for purge gas 8 caused by the view opening 9 contributes to turbulence of an outflowing purge gas, resulting in better cooling. At a distance of 8 mm to the view opening 9, twelve outlet openings 8.1 for purge gas are formed in a circle around the view opening 9. Each outlet opening 8.1 has a diameter of 1 mm. The flushing openings 8.1 prevent fouling of the end face of the instrument housing 6 or the view opening 9 formed therein.

At a distance of 20 mm to the right edge of the instrument housing 6, the purge gas connection 7 is arranged, which has an opening diameter of 11 mm. Not shown are further openings for the arrangement of sensors for temperature monitoring of the instrument holder. 1

For mounting a camera (not shown), an aluminum tube 10 is provided, which is inserted into the instrument housing 6. The aluminum tube 10 is 271 mm long and has a diameter of 18 mm. On the left side, a metric fine thread M15 x 1 is cut to a depth of 10 mm. On the right side a metric thread M15 x 1.5 is cut to a depth of 12 mm. Furthermore, the aluminum tube 10 has two elongated holes 10.1 and 10.2.

The relatively compact design of the instrument holder 1 and the possibility of changing the penetration depth into the high-temperature region of a high-temperature system has the advantage that the heat input caused by thermal radiation into the instrument holder 1 can be reduced. Preferably, the penetration depth is always adjusted so that the protective housing 2 is located in a wall region of a refractory lining of a high-temperature system. This allows liquid-free cooling of instruments with a cooling gas flow that can be provided with ambient air.

An embodiment of the system according to the invention for monitoring the interior of high-temperature systems, such as furnaces, in particular furnaces, burners or thermal process chambers with operating temperatures above 900 ° C, comprises an instrument holder 1 according to the FIG. 1 , Furthermore, the system comprises a camera, which is held by the instrument holder 1 and a control device for processing camera signals. Expediently, the control device can also have a display unit for the visualization of camera signals. For signal-technical and / or electrical connection of the control device with the camera temperature-resistant connection cable can be used. According to one embodiment, a wireless transmission of camera signals via radio can also be provided. As a camera, for example, a digital camera or a thermal imaging camera can be used.

Furthermore, the system for liquid-free interior monitoring of high-temperature systems comprises a supply device for providing a gas flow to the instrument holder 1. The gas source is ambient air, wherein the supply device may also have connections for external gas sources. Furthermore, the supply device to pressure regulator and flow meter, which can be used to control the volume flow of at least two gas streams independently of each other or regulate. The volume flows for cooling gas or purge gas can be regulated as a function of temperature data provided by temperature sensors of the instrument holder 1. Thus, the volume flow can be increased if a temperature increase is detected at the temperature sensors of the instrument holder 1. Liquid separators prevent the flow of gas from entering the interior of a high-temperature system.

The supply device and the control device for processing camera signals are preferably accommodated in a common housing.

With the system according to the invention can be achieved at an ambient temperature in the high temperature range up to 1700 ° C, a permanent instrument cooling of the instrument to a temperature not exceeding 100 ° C. A corresponding cooling is achieved at a purge gas pressure of at least 1 bar and a cooling gas pressure of at least 0.5 bar, wherein the instantaneous flow must be at least 0.6 m ³ / min. Ambient air can be used as the gas source.

LIST OF REFERENCE NUMBERS

1

instrument holder

2

housing

2.1

Outer tube

2.2

Inner tube

3

Inlet opening for cooling gas

3.1

perforation

4.1

Outer flow channel for cooling gas

4.2

Inner flow channel for cooling gas

5.1

Outlet opening for cooling gas outer flow channel

5.2

Outlet opening for cooling gas inner flow channel

6

instrument Enclosures

7

Inlet opening for purge gas

8th

Flow channel for purge gas

8.1

Outlet opening for purge gas

9

Outlook opening

10

Fastener / aluminum tube

10.1 / 10.2

Long hole

11

fastening device

11.1

holes

12

guide

A

High-temperature side

B

Ambient temperature side

Claims (15)

1. Instrument holder (1) for liquid-free instrument cooling, comprising:

   an at least double-walled protective housing (2) with

   - an inlet opening for cooling gas (3)

   - at least one flow channel for cooling gas (4.1/4.2), and

   - at least one outlet opening for cooling gas (5.1/5.2), and

   an instrument housing (6) capable of being arranged in a flow channel for cooling gas (4.1/4.2), with

   - an inlet opening (7) for flushing gas (7)

   - a flow channel for flushing gas (8)

   - at least one outlet opening for flushing gas (8.1),

   - a viewing opening (9) for an instrument and

   - fasteners (10) for fastening an instrument in the instrument housing (6), whereby the outlet opening for cooling gas (5.1/5.2) the outlet opening for flushing gas (8.1) and the viewing opening (9) for an instrument on a side (A), facing a high temperature, of the instrument holder (1) are arranged in the viewing direction of an instrument capable of being arranged in the instrument housing.
2. Instrument holder (1) in accordance with Claim 1, characterised in that the protective housing (2) is designed with an outer tube (2.1) and at least one inner tube (2.2), which are arranged in such a way that between the outer tube (2.1) and the at least one inner tube (2.2) a flow channel for cooling gas is constructed (4.1).
3. Instrument holder (1) in accordance with Claim 2, characterised in that the outer tube (2.1) projects above a front side of the at least one inner tube (2.2) on the outlet opening for cooling gas (5.1).
4. Instrument holder (1) in accordance with one of Claims 1 to 3, characterised in that the protective housing (2) projects above the instrument housing (6).
5. Instrument housing (1) in accordance with one of Claims 1 to 4, characterised in that the instrument housing (6) is arranged in such a way that between the instrument housing (6) and the protective housing (2), a flow channel for cooling gas (4.2) is formed.
6. Instrument holder (1) in accordance with one of Claims 1 to 5, characterised in that an internal wall of the protective housing (2) has at least one aperture (3.1) corresponding to a flow channel for cooling gas (4.1).
7. Instrument holder (1) in accordance with one of Claims 1 to 6, characterised in that the inlet opening for cooling gas (3), the inlet opening for flushing gas (7) and at least one connection for an instrument are arranged on a side (B), facing away from a high temperature, of the instrument holder (2).
8. System for the liquid-free interior monitoring of high-temperature systems with an instrument holder in accordance with Claims 1 to 7, comprising an instrument which is held by the instrument holder (1), a control unit for processing signals from the instrument and a supply unit for providing a gas stream to the instrument holder (1).
9. System in accordance with Claim 8, characterised in that the supply unit has a flow meter with which the volume flow of the gas stream can be determined.
10. System in accordance with one of Claims 8 or 9, characterised in that the supply unit provides the instrument holder (1) with a cooling gas stream and a flushing gas stream, whereby the cooling gas stream and the flushing gas stream are adjustable independently of one another.
11. Method for liquid-free instrument cooling with an instrument holder (1) in accordance with Claims 1 to 7, whereby for the purposes of cooling an instrument held by the instrument holder (1), a volume flow for a cooling gas and/or for a flushing gas is supplied to the instrument holder depending on a temperature of the instrument, a temperature of the instrument holder (1) and/or an ambient temperature of the instrument holder (1), whereby the gases for the cooling and the flushing, during use in a high-temperature system, are diverted into the interior of the high-temperature system in the viewing direction of the instrument.
12. Method in accordance with Claim 11, characterised in that the volume flow for a cooling gas and/or for a flushing gas is regulated depending on a temperature of the instrument, a temperature of the instrument holder (1) and/or an ambient temperature of the instrument holder (1).
13. Method in accordance with one of Claims 11 or 12, characterised in that, by way of a cooling gas and/or flushing gas, air and/or an inert gas is used.
14. Method in accordance with one of Claims 11 to 13, characterised in that a cooling gas pressure and/or a flushing gas pressure is set in the range 0.1 bar to 8.5 bar.
15. Method in accordance with one of Claims 11 to 14, characterised in that a total volume flow - for cooling gas and flushing gas - of at least 0.6 m³/min is set.

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