GB2310293A

GB2310293A - Camera system

Info

Publication number: GB2310293A
Application number: GB9602440A
Authority: GB
Inventors: Peter Charles Richardson
Original assignee: P C Richardson & Co
Current assignee: P C Richardson & Co
Priority date: 1996-02-07
Filing date: 1996-02-07
Publication date: 1997-08-20
Also published as: GB9602440D0

Description

CAMERA SYSTEM This invention relates to a camera system, and particularly, but not exclusively, to a camera system for use in areas of high temperature, and to a housing for such a camera system.

It is often necessary to obtain visual information relating to objects or surfaces situated within a high temperature area.

For example, it is necessary from time to time to inspect an inner lining of a factory chimney to ensure that the chimney is in good repair, or to carry out repairs if necessary.

It is known to shut down a chimney which requires inspection.

This can sometimes also necessitate the shutting down of a factory serviced by the chimney. It is then necessary to allow the chimney to cool before sending in personnel to inspect the inner lining to take photographs if necessary prior to carrying out any repairs.

A disadvantage of this known method of inspecting the inner lining of a chimney is that it necessitates the shutting down of the chimney and/or the factory serviced by the chimney.

This results in the chimney and/or factory being out of commission which can be expensive.

It is also necessary to predict the level of repairs which may be necessary and to schedule in advance an appropriate shutdown time of the chimney and/or factory to allow the repairs to be carried out. It is not easy to predict the level of repairs necessary, and therefore the shutdown time that has been estimated may be inappropriate. This can result either in insufficient time being allowed to carry out the repairs, or a longer shutdown than necessary occurring.

If a longer shutdown than necessary has been scheduled, production time may be lost, which may be expensive.

According to the present invention there is provided a camera system comprising: a heat resistant housing comprising at least one window; mounting means for mounting one or more devices within the housing.

Preferably, the housing comprises an inner casing containing the mounting means, and an outer casing.

Advantageously, the inner casing is heat resistant.

Conveniently the inner casing is also acid resistant.

If the camera system according to the present invention is used to inspect the inner lining of the chimney, exhaust gases passing through the chimney may be acidic, and it is therefore important that the one or more devices mounted within the inner casing are protected from damage by acid.

Preferably, the inner casing is made from a man made laminate.

Alternatively the inner casing may be made from any other suitable material. The man made laminate may be chosen from any one of a number of suitable laminates which are currently available. A particularly useful type of laminate is the type used for laboratory work tops which is both acid and temperature resistant.

The one or more windows formed in the inner casing may be formed from a high temperature glass. Alternatively they can be formed from high temperature plastics. Preferably, the material used to form the windows is resistant to temperatures of up to about 5000C.

Preferably, the outer casing is also heat resistant. The outer casing can also be made from a man made laminate or other suitable material.

The outer casing further comprises one or more windows corresponding to the one or more windows in the inner casing.

Advantageously, the outer casing is coated with a heat reflective layer such as a heat reflective cloth.

Conveniently, the reflective cloth is an aluminised ceramic cloth.

Preferably, the outer casing is plated with a ceramic shell to provide further heat resistance.

Conveniently, the ceramic shell is formed from ceramic material such as Monolux 500.

The inner casing and the outer casing are spaced apart from one another, and the inter-case space may be kept cool by means of compressed air fed into the inter-case space. Alternatively, cooling devices such as pre-cooled drycoal packs may be positioned in the inter-case space providing cooling.

If initial ambient temperature is low, for example, less than 10 C, then no further cooling device is required if the temperature in use does not exceed 2000C and if the time that the camera is exposed to this temperature is no more than two hours.

If compressed air is fed into the inter-case space, it is conveniently supplied to the housing by means of pipes or tubing.

Advantageously the housing further comprises a deflector shield. The deflector shield is substantially conical in shape and provides additional insulation against hot gases passing through a chimney being inspected, and serves to deflect the gases away from the windows. The shield may also provide aerodynamic stability to the camera system whilst in use.

Preferably, the camera system comprises four cameras positioned substantially at right angles to one another and mountable on the mounting means.

The cameras are mounted in substantially the same horizontal plane as one another.

The inner casing and outer casing both comprise four windows positioned appropriately to allow each of the four cameras to view the surroundings through a respective pair of windows.

Preferably, the camera system further comprises a "quad unit" which enables the signals from the four cameras to be transmitted through a single co-axial cable and viewed simultaneously on a single viewing screen, or recorded on video tape.

Advantageously, the camera system further comprises lighting means positioned within the inner casing to allow cameras to operate effectively within areas of relative darkness.

Advantageously, the system further comprises a power supply contained within the inner casing. The power supply may comprise, for example, one or more dry batteries.

Conveniently, the system further comprises a co-axial cable extending from the inner casing through the outer casing and extending to a control centre. The co-axial cable may be used to connect the cameras to a recording device in order that personnel may study information from the cameras in real time.

The co-axial cable preferably comprises insulation. The cable may be inserted by using, for example, lagging and/or compressed air.

Alternatively, the recording device may be positioned within the inner casing. In such a situation although the information obtained from the cameras may be analysed by personnel this cannot take place in real time and must be carried out after the camera system has been taken out of the environment in which the information was collected.

Alternatively, the camera system may comprise transmitters and receivers which emit radio signals which allow information from the cameras to be transmitted to a recording device without the need for co-axial cable.

Embodiments of the invention will now be further described by way of example only with reference to the accompanying drawings in which: Figure 1 is a schematic representation of a camera system according to the present invention; Figure 2 is a cross sectional representation of the camera system of Figure 1; Figure 3 is a plan view of the system of Figure 1 (with lid removed; Figure 4 is a schematic representation of the camera system according to Figure 1 being lowered into a chimney to be inspected; and Figure 5 is a schematic representation of the camera system of Figure 1 being lowered into the chimney to be inspected through an inspection port.

Referring to the Figures, a camera system according to the present invention is designated generally by the reference numeral 1. The system 1 comprises the housing 2 having an inner casing 20 and an outer casing 21.

The housing 2 serves to provide a structure in which to mount component parts of a camera unit. Because one of the main uses of a system 1 according to the present invention is to inspect an inner lining of a chimney which is still in commission, it is important to protect the component parts of the camera unit which may include electronic devices and components from heat and acids contained in the flue gases within the chimney, and also to provide stability against buffeting and turbulence caused by the movement of gases within the flue.

The inner casing 20 may be made from a man made laminate which is resistant to both heat and acid attack.

The inner casing comprises a plurality of windows 30 which are formed from high temperature glass.

The outer casing 2 is also constructed from a man made laminate. The outer casing is further coated with a heat reflective cloth (not shown) and further plated with a ceramic shell 22. The outer casing also comprises a plurality of windows 3 formed from a high temperature glass.

The housing 2 further comprises a conical deflector 4 attached to a lower area of the outer casing 2. The shield 4 provides additional insulation against hot gases travelling through the chimney being inspected, and also serves to deflect gases away from the windows 3, 30. In addition the shield provides aero dynamic stability for the system whilst in use.

The inter-case space 24 may be kept cool by compressed air which is fed through a hose 5 leading from a compressor situated at ground level outside the chimney.

However, in an alternative embodiment, the space 24 may be cooled by using pre-cooled glycol packs which may be packed into the inter-case space before the system is lowered into a chimney.

Warm air generated from the cooling process is vented into the chimney flue.

A video camera system is mounted within in the inner casing 20 on mounting means 26. The video system comprises four camera units 32 mounted in substantially the same horizontal plane and at substantially 90" to one another. The four cameras therefore provide a substantially full circumferential view of the chimney lining at any particular level at which the system is positioned.

The cameras are connected to a "quad unit" which enables the signals from each of the four cameras to be transmitted through a single co-axial cable and to be viewed simultaneously on a single viewing screen or to be recorded on a single video tape.

Lighting 34 is also supplied to enable the cameras to operate efficiently even in a darkened environment.

Power for the system may be provided by dry cell batteries 28 also positioned within the inner casing 20.

The signal from the cameras 32 is transmitted to a receiver or recording device via a single co-axial cable. If compressed air is supplied to the system via a hose, then the co-axial cable may run inside the hose. The hose carrying the compressed air thus insulates the co-axial cable.

Referring to Figures 4 and 5, the camera system 1 may in use be raised into position at the top of a chimney 40, the lining of which is to be inspected, via an adjustable purpose made davit 42 secured to an access platform 44 on the exterior 46 of the chimney shell 40. The camera system 1 may then be skewed around centrally over the flue by means of a davit turntable 48 allowing the system 1 to descend into the chimney 40. As the camera system 1 descends into the chimney 40 the camera transmits visual information and allows remote inspection of the chimney to take place.

Referring to Figure 5, a chimney comprising an inspection door 52 is shown. The inspection door 52 allows the camera system 1 to be lowered from the point of the access door 52 rather than from the top of the chimney. This can be particularly useful if part inspection of the lower portion of the chimney is required. It obviates the need to lower the camera system from the top of the chimney.

After a successful inspection of a chimney lining, the system 1 may be raised out of the chimney swung clear and removed.

Although the present invention has been described primarily in terms of a camera system for use in inspecting an inner lining of a chimney, the camera system could be used in many other different situations in which it is necessary to obtain visual information from high temperature environments.

Claims

CLAIMS:

1. A camera system comprising: a heat resistant housing comprising at least one window; mounting means for mounting one or more devices within the housing.

2. A camera system according to claim 1, wherein the housing comprises an inner casing containing the mounting means, and an outer casing.

3. A camera system according to claim 2, wherein the inner casing is heat resistant.

4. A camera system according to claim 2 or claim 3, wherein the inner casing is acid resistant.

5. A camera system according to any one of claims 2 to 4, wherein the inner casing is made from a man-made laminate.

6. A camera system according to any one of the preceding claims, wherein the at least one window is formed from a high temperature resistant glass.

7. A camera system according to any one of claims 1 to 5, wherein the at least one window is formed from a high temperature resistant plastics material.

8. A camera system according to any one of the preceding claims, wherein at least one window is resistant to temperatures of up to about 5000C.

9. A camera system according to any one of claims 2 to 8, wherein the outer casing is heat resistant.

10. A camera system according to any one of claims 2 to 9, wherein the outer casing further comprises at least one window corresponding to the at least one window in the inner casing.

11. A camera system according to any one of claims 2 to 10, wherein the outer casing is coated with a heat reflective layer.

12. A camera system according to claim 11, wherein the heat reflective layer comprises a heat reflective cloth.

13. A camera system according to claim 12, wherein the heat reflective cloth is an aluminised ceramic cloth.

14. A camera system according to any one of claims 2 to 13, wherein the outer casing is coated with a ceramic shell.

15. A camera system according to claim 14, wherein the ceramic shell is formed from ceramic material such as Monolux 500.

16. Á camera system according to any one of claims 2 to 15, wherein the inner casing and the outer casing are spaced apart from one another to form an inter-case space which intercase space is kept cool by means of compressed air fed into the inter-case space.

17. A camera system according to any one of the preceding claims, wherein the housing further comprises a deflector shield.

18. A camera system according to claim 18, wherein the deflective shield is substantially conical in shape.

19. A camera system according to any one of the preceding claims, comprising four cameras positioned substantially at right angles to one another and mountable on the mounting means.

20. A camera system according to claim 19, wherein the cameras are mounted in substantially the same horizontal plane as one another.

21. A camera system according to claim 19 or claim 20, wherein the inner casing and the outer casing each comprise four windows positioned appropriately to allow each of the four cameras to view the surrounding through a respective pair of windows.

22. A camera system according to any one of claims 19 to 21, further comprising a quad unit enabling the signals from the four cameras to be transmitted through a single coaxial cable.

23. A camera system as claimed in any one of claims 2 to 22, further comprising lighting means positioned within the inner casing to allow effective operation within areas of relative darkness.

24. A camera system according to any one of claims 2 to 23, further comprising a power supply contained within the inner casing.

25. A camera system according to any one of claims 2 to 24, further comprising a coaxial cable extending from the inner casing through the outer casing and extending to a control centre.

26. A camera system according to claim 25, wherein the coaxial cable comprises insulation.

27. A camera system according to any one of claims 2 to 26, wherein a recording device is positioned within the inner casing.

28. A camera system according to any one of claims 2 to 26, further comprising transmitters and receivers which emit radio signals which allow information to be transmitted from the camera system to a recording device.

29. A camera system substantially as hereinbefore described with reference to the accompanying drawings.