WO2000039515A1

WO2000039515A1 - Sighting apparatus for observing the inside of a furnace

Info

Publication number: WO2000039515A1
Application number: PCT/KR1999/000018
Authority: WO
Inventors: Bae-Hun Kim
Original assignee: Ro Ne Sight Co., Ltd
Priority date: 1998-12-28
Filing date: 1999-01-13
Publication date: 2000-07-06
Also published as: AU1984199A; KR19990045712A

Abstract

This invention is to provide a sighting apparatus by which a user can directly observe the inside of a furnace during operating and promptly control according to the condition inside the furnace. The sighting apparatus can completely seal up the inside of the furnace and is operable with small operation costs. The sighting apparatus includes a housing having a double casing structure keeping a space between the cases into vacuum condition and a sighting hole at a front end thereof and being sealably positioned into an opening formed on a wall of a furnace, a lens block detachably mounted inside the housing, a plurality of object lenses and ocular lenses respectively positioned in the lens block, a visible ray cut-off filter and an infrared ray transmitting filter positioned next to the last ocular lens in the lens block, a screen lens mounted at an inlet portion of the lens block, and a cooling means for cooling the lens block with the compressed air. The sighting apparatus has a simple structure, provides clean image of the inside of the furace, and is easy in maintenance and repair.

Description

Sighting Apparatus for Observing the Inside of a Furnace

FIELD OF THE INVENTION

This invention relates to a sighting apparatus for observing the inside of a furnace, and more particularly to, a sighting apparatus for observing the inside of a furnace by which an user can directly observe the inside of a furnace at any time, so that the user can promptly control overall process condition of the inside of the furnace on the basis of the observation result.

DESCRIPTION OF THE PRIOR ART

In general, industrial furnaces are classified into many different kinds according to the use purpose. There are, for example, an industrial incinerator for incinerating waste products, a smelting furnace for smelting metals for an ironworks, a gas furnace for melting glasses, a cement kiln, a pottery kiln, a calcining furnace and the likes.

When users use the furnaces, one of the users' common needs is to observe the inside of the furnace with clean image at any time during the operation of the furnace.

When the furnace starts working, the furnace is continuously operated during a predetermined period of time unless any particular troubles are occurred. Therefore, the user should see the inside of the furnace at any time to inspect the status of the inside of the furnace.

A number of attempts have been made in the prior art to design an effective sighting apparatus for the furnaces.

Figures 1 and 2 show an embodiment of one attempt of the known prior art for observing the inside of the industrial furnace. Referring to figures 1 and 2, the previously used furnace has an opening 2 of a predetermined size on a wall of the furnace and a door 3, which can be opened and shut, mounted on an entrance of the opening 2. Therefore, in case of need, the user usually opens the door 3, and then, see the inside of the furnace through the opening 2.

The above method forms about seventy percent of the furnaces which is presently used. In the prior art, when the user observes the inside of the furnace, the user should use a face mask 5 having an infrared glass 4 in order to protect the user's eyesight and to prevent strong visible ray.

However, the method has following disadvantages:

(a) since the opening is formed on the wall of the furnace, heating effect is dropped, and air comes into the furnace from the outside, thereby bringing about change of the air mixed proportion;

(b) the user may be burnt due to flying sparks from the furnace during seeing the inside of the furnace;

(c) it is inconvenient, since the user must use the face mask 5 to prevent the strong heat and light and to see the clear image; and,

(d) a field of vision is restricted only in a very partial area since the opening of the furnace is small and the wall of the furnace is thick. Another attempt to solve the problems of the prior art and to reduce its cost has been made. Figures 3 and 4 show another embodiment of the prior art. Referring to figures 3 and 4, a window 6 is located on the wall 1 of the furnace in order for the user to can see the inside of the furnace through the window 6.

In the prior art, the furnace must be not high in the temperature and the window glass has to contain a lot of quartz being resistant to heat.

However, the above method also has following disadvantages:

(a) the window glass becomes low in a degree of transparency and gives bad images as time passed, since the glass is resistant to heat but weak in an abrasion and a corrosion;

(b) the window glass is easy to break due to a strong shock; and,

(c) only very partial area can be observed since a field of vision is restricted as the previously mentioned prior art.

In case of using furnace which is large sized, or necessary to control the temperature of the furnace precisely, a sighting apparatus has been used as shown in figure 5.

Figure 5 shows a longitudinal sectional view of further another embodiment of the prior art. The prior art is a method that an image display equipment referred as a lens tube is inserted into the furnace to observe the inside of the furnace by a monitor. The lens tube 7 is put inside the furnace through the opening 2 formed on a wall 1 of the furnace. The lens tube 7 has to essentially include a cooling system using an air compressor or water and a retract system which is driven when the temperature of the inside of the furnace equals or exceeds a selected temperature, since the lens tube is located inside the furnace of high temperature. Through the cooling system and the retract system, the high priced lens tube 7 can be prevented from damage caused by the high temperature. However, the method using the lens tube for observing the inside of the furnace also has following disadvantages:

(a) a set of the lens tube is too expensive ( about fifty million won ~ five hundred million in Korean money);

(b) it is too high in the cost of maintenance and repair, since the high priced equipment is all damaged, if the cooling system and the retract system are out of order;

(c) the installation structure of the components installed in the furnace is very complicated;

(d) it is impossible that a local operator operating the furnace sees the image of the status of the inside of the furnace on the spot;

(e) it is difficult in repair and there is every probability of malfunction, since components necessary to cooling of the lens tube are very complicated; and, (f) the lens tube may be heavily damaged due to a change of pressure of the inside of the furnace, since it is impossible to completely seal up the furnace with the lens tube.

SUMMARY OF THE INVENTION It is, accordingly, an object of the present invention to overcome the disadvantages in the prior art by providing a sighting apparatus for observing the inside of a furnace which can seal up the inside of the furnace completely and sharply reduce the heat loss, thereby increasing thermal efficiency.

Another object of the present invention is to provide a sighting apparatus for observing the inside of a furnace which is easy in repair and control, and can reduce the change cost of lens, since in case of damage of lens, only the damaged lens of lenses in a lens block is changed.

Further another object of the present invention is to provide a sighting apparatus for observing the inside of a furnace which is simple in its structure and installation, compared with the prior arts, so that an user can accurately observe the operation condition of the inside of the furnace without difficulty, thus stably operating the furnace.

Still further object of the present invention is to provide a sighting apparatus for observing the inside of a furnace which is inexpensive and is applicable to all industrial furnaces, to spread easily.

Consistent with the foregoing objects, and in accordance with the invention as embodied and broadly described herein, a superior sighting apparatus for observing the inside of a furnace is disclosed.

The preferred sighting apparatus includes: a housing of double casing structure which keeps a space between the cases into vacuum condition, has a small sighting hole at a front end thereof, and is sealably positioned into an opening formed on a wall of a furnace; a lens block detachably mounted inside the housing; a plurality of object lenses and ocular lenses positioned in the lens block in order; a visible ray cut-off filter positioned next to the last ocular lens in the lens block; an infrared ray transmitting filter positioned next to the visible ray cut-off filter; a screen lens sealably fixed at an inlet portion of the lens block; and a cooling means for cooling the lens block with the compressed air.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become apparent upon reading to following detailed description of exemplary embodiments and upon reference to the accompanying drawings, in which: Fig. 1 is a brief view of an embodiment of the conventional prior arts;

Fig. 2 is a sectional view taken on line A-A in Fig. 1; Fig. 3 is a brief view of another embodiment of the prior arts; Fig. 4 is a sectional view taken on line B-B in Fig. 3;

Fig. 5 is a longitudinal sectional view of further another embodiment of the prior arts;

Fig. 6 is a longitudinal sectional view showing essential parts according to a preferred embodiment of the present invention;

Fig. 7 is a front view of Fig. 6; Fig. 8 is a detail view of portion "C" in Fig. 6; Fig. 9 is a detail view, with portion broken away for the sake of clarity, of one of nozzles of the present invention; and Fig. 10 is a brief view showing another preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION The presently preferred embodiments of the invention will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout.

Referring to figures 6 through 10, preferred embodiments of this invention are more specifically described as follows.

In figure 6, a sighting apparatus for observing the inside of a furnace includes a housing 8 of double casing structure which has a small sighting hole 9 at a middle part of a front end of the housing 8 for observing the inside of the furnace. The housing 8 of double casing structure which keeps a space between the cases into the vacuum condition is sealably located in an opening 2 formed on a wall 1 of the furnace. By keeping the vacuum condition of the housing 8, it is possible to minimize the transmission of heat of high temperature into the housing 8.

The housing 8 is made of titanium or stainless steel material which is low in a thermal conductivity and a heat expansion and resistant to corrosion.

A lens block 10 is detachably mounted inside the housing 8. The lens block 10 has a plurality of object lenses 11 and ocular lenses 12, a visible ray cut-off filter 13 for cutting off the visible ray and an infrared ray transmitting filter 14 for selectively transmitting the infrared ray. The object lenses 11, the ocular lenses 12, the visible ray cut-off filter 13, and the infrared ray transmitting filter 14 are positioned in the lens block 10 in order.

The object lenses 11 reverse the flame image taken from the furnace through the small sighting hole 9 and transmit the reversed image to the ocular lenses 12. The ocular lenses 12 right the reversed flame image and transmit the image through the visible ray cut-off filter 13 and the infrared ray transmitting filter 14 to a screen lens 17. The flame image can be observed through the screen lens

17 by an user's eyes, being enlarged over 100 percent by the lenses.

It will be appreciated that the object lenses and the ocular lenses may have respectively two or more lenses. In this embodiment, the object lens and the ocular lens respectively have two lenses.

The screen lens 17 is sealably fixed in a concave groove

18 formed at an inlet portion of the lens block 10 as shown in figure 8. The lens block 10 is fixed to the housing 8 by fixing bolts 16 at several positions. At this time, insulating materials are mounted between the housing 8 and the lens block 10 to certainly seal the space between the housing 8 and the lens block 10, so that the thermal conductivity can be considerably reduced.

The lens block 10 also has cooling means for cooling the housing 8 by jetting air of low temperature into the housing 8. As shown in figure 7, the cooling means has an air line

19 formed to lead to the lens block 10, an input air compressor 20 connected to one portion of the air line 19 by an air pipe, an output air compressor 21 connected to another portion of the air line 19 by an air pipe, and a plurality of nozzles 22 mounted on the air line 19 to cool down the lens block 10 mounted in the housing 8.

As shown in figure 7, the plurality of nozzles 22 are located on the outside of the lens block 10. The lens block 10 also has a plurality of cooling pins 23 at the outer circumference of the lens block 10 to increase the cooling efficiency. The cooling pins 23 are inclined from the lens block 10 toward the air jet portion. By the inclination of the cooling pins 23, the cooling pins 23 are contacted with a large quantity of air for a long time to increase the cooling efficiency. As shown in figure 9, each of the nozzles 22 for jetting the compressed air has an air jet hole 22a at an outlet of the nozzle 22 so that the temperature of the air jetted through the air jet hole 22a can be lowered to 50 percent.

The amount of the air output from the output air compressor 21 is small at about 30 percent in comparison to the amount of the air input from the input air compressor 20. The amount of the air of 30 percent is jetted into the furnace through the small sighting hole 9, such that high temperature and dust cannot come into the housing 8 through the small sighting hole 9 from the furnace.

If the power supply is shut off during operation of the sighting apparatus of the present invention, the input air compressor 20 and the output air compressor 21 are not driven, and then, the cooling means stops working, resulting in a damage of the lenses in the lens block 10 by the high heat from the furnace. Therefore, considering security, it is preferable that the input air compressor 20 and the output air compressor 21 are supplied with the power supply through a nobreak power supply equipment. a shading member 25 is extended from the outer circumference of the screen lens 17, so that the projected image is not dim by the source of light from the outside. That is, when the user directly distinguishes the image finally projected to the screen lens 17, the shading member 25 is provided to protect the projected image from dimness due to the sunlight, or other light sources. Therefore, it is preferable that the shading member 25 is extended from the screen lens 17 to about 10 cm, and made of titanium or stainless steel having a good heat-resistance, in consideration of its durability.

Figure 10 shows another embodiment of the present invention. Referring figure 10, the small sighting hole 9 is formed somewhat below the middle part of the housing 8, and a prism 24 is diagonally mounted at an upper part of the object lens 11 positioned at the front end of the lens block 10. Therefore, the user can observe the all inside of the furnace at an angle of 45° through the diagonally mounted prism 24.

Those skilled in the art will readily recognize that these and various other modifications and changes may be made to the present invention without strictly following the exemplary application illustrated and described herein and without departing from the true spirit and scope of the present invention, which is set forth in the following claims.

Claims

WHAT IS CLAIMED IS:

1. A sighting apparatus for observing the inside of a furnace comprising: a housing having a double casing structure and a sighing hole at a front end thereof, the housing keeping a space between the cases into vacuum condition, the housing being sealably positioned into an opening formed on a wall of a furnace; a lens block detachably mounted inside the housing; a plurality of object lenses positioned in the lens block; a plurality of ocular lenses positioned next to the object lenses in the lens block; a visible ray cut-off filter for cutting off the visible ray, the visible ray cut-off filter positioned next to the last ocular lens in the lens block; an infrared ray transmitting filter for selectively transmitting the infrared ray, the infrared ray transmitting filter positioned next to the visible ray cut-off filter; a screen lens for directly viewing an image from the inside of the furnace, the screen lens mounted at an inlet portion of the lens block; and a cooling means for cooling the lens block with the compressed air.

2. A sighting apparatus according to claim 1, wherein the cooling means includes: an air line formed to lead to the lens block; an input air compressor connected to one portion of the air line; an output air compressor connected to another portion of the air line; and a plurality of nozzles for jetting the compressed air from the input air compressor to the inside of the housing to cool down the lens block mounted in the housing, each of the nozzles mounted on the air line.

3. A sighting apparatus according to claim 1, wherein the lens block further includes a plurality of cooling pins inclined from an outer circumference of the lens block toward the air jet portion.

4. A sighting apparatus according to claim 1, wherein the housing is made of titanium or stainless steel material which is low in a thermal conductivity and a heat expansion and resistant to corrosion.

5. A sighting apparatus according to claim 1, wherein the object lenses and the ocular lenses include respectively two or more lenses.

6. A sighting apparatus according to claim 1 or 2, wherein the cooling means is set up to have the amount of the output air which is smaller at 30 percent than the amount of the input air, such that the air amount of 30 percent is jetted into the furnace through the small sighting hole.

7. A sighting apparatus according to claim 1, wherein a shading member is extended from an outer circumference of the screen lens, so that the projected image is not dim due to the source of light from the outside.

8. A sighting apparatus according to claim 1, wherein the lens block further includes a prism diagonally mounted at an upper part of the object lens positioned at the front end of the lens block, so that an user can observe the all inside of the furnace at an angle of 45° through the diagonally mounted prism.