CN105865194B

CN105865194B - Heating furnace

Info

Publication number: CN105865194B
Application number: CN201610224223.5A
Authority: CN
Inventors: 降宇波; 吴德慧; 彭思; 谢非; 沈琪
Original assignee: China Nuclear Power Engineering Co Ltd
Current assignee: China Nuclear Power Engineering Co Ltd
Priority date: 2016-04-12
Filing date: 2016-04-12
Publication date: 2020-04-03
Anticipated expiration: 2036-04-12
Also published as: CN105865194A

Abstract

The invention relates to a heating furnace, which comprises a furnace shell with an opening at the lower part and a furnace liner assembly arranged in the furnace shell in a penetrating way, wherein the furnace liner assembly comprises a furnace liner and a furnace platform which is arranged in the furnace liner and can be lifted, the periphery of the lower part of the furnace liner and the bottom of the furnace shell are sealed by a lower sealing assembly, the upper part of the furnace liner is provided with a furnace liner top connecting pipe, and the periphery of the furnace liner top connecting pipe and a furnace shell top plate are sealed by an upper sealing assembly; a plurality of heating elements inserted from the top of the furnace shell are arranged between the inner wall of the furnace shell and the furnace pipe. The heating furnace can heat the radioactive materials in a closed environment, and can continuously finish heating by using other heating bodies under the condition that partial heating bodies fail; in a weak sealing link, a structure capable of performing double sealing and pressure detection is designed, so that the sealing reliability is improved; after heating is finished, forced cooling can be carried out, so that the cooling time is saved, and the production efficiency is improved; by adopting a modular structure, the device has clear layers, realizes the quick overhaul and replacement of parts and saves time.

Description

Heating furnace

Technical Field

The invention belongs to the field of heating equipment, and particularly relates to a heating furnace which is mainly used for heating toxic or radioactive materials.

Background

In the chemical industry field, often need to heat the material. When the material has toxicity or radioactivity, the material needs to be heated in a closed environment in order to avoid the diffusion of the toxicity or radioactivity; meanwhile, due to the existence of radioactivity, the maintenance time is required to be as short as possible when the heating equipment is maintained and replaced, and the existing heating equipment cannot meet the requirements. In addition, in the batch heating mode, the furnace temperature needs to be reduced to a reasonable temperature before the materials can be taken out, so that the temperature reduction time is long, and the improvement of the productivity is greatly restricted. When the heating element breaks down, the existing electric heating furnace is difficult to continue to complete the heating work.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a heating furnace which can heat radioactive materials in a closed environment and can continuously finish heating by using other heating bodies under the condition that partial heating bodies fail; aiming at the sealing problem under the high-temperature condition, a structure capable of carrying out double sealing and pressure detection is designed at the weak link of sealing, so that the sealing reliability is improved; after heating is finished, forced cooling can be carried out, so that the cooling time is greatly saved, the production efficiency is improved, and the economic efficiency is good; the heating furnace adopts a modular structure, is well-arranged, realizes the quick overhaul and replacement of parts and saves time.

In order to achieve the above purposes, the invention adopts the technical scheme that: the heating furnace comprises a furnace shell with an opening at the lower part and a furnace liner assembly penetrating through the furnace shell, wherein the furnace liner assembly comprises a furnace liner and a furnace platform which is arranged in the furnace liner and can be lifted, the lower periphery of the furnace liner and the bottom of the furnace shell are sealed through a lower sealing assembly, the upper part of the furnace liner is provided with a furnace liner top connecting pipe, and the periphery of the furnace liner top connecting pipe and a furnace shell top plate are sealed through an upper sealing assembly; and a plurality of heating elements inserted from the top of the furnace shell are arranged between the inner wall of the furnace shell and the furnace liner.

Furthermore, a hearth air inlet pipe and an air guide pipe are arranged at the bottom of the furnace shell, and a hearth exhaust pipe is arranged at the top of the furnace shell.

Furthermore, a plurality of temperature measuring elements inserted from the top of the furnace shell are arranged between the inner wall of the furnace shell and the furnace pipe.

Furthermore, the heating element is a reciprocating winding radiant tube, and two adjacent sections of radiant tubes are isolated by a ceramic piece; the temperature measuring element is a thermocouple.

Further, the upper sealing assembly is a secondary sealing structure which comprises an upper connecting pipe, an adapter and a gland; the lower part of the upper connecting pipe is welded with the upper part of the connecting pipe at the top of the furnace pipe, the upper part of the upper connecting pipe is connected with the lower part of the adapter through threads, and the upper part of the adapter is connected with the gland through threads; the joint between the adapter and the upper connecting pipe and the joint between the adapter and the gland are sealed through the adapter sealing gasket.

Further, the adapter is cross cavity structures, including horizontal pipe and vertical pipe, horizontal pipe is used for stove courage exhaust and stove courage internal pressure measurement, insert the thermocouple in vertical intraductal for to the measurement of stove courage internal temperature.

Further, the secondary sealing structure also comprises an upper pipe joint, a middle pipe joint and a lower pipe joint which are connected in sequence and used for sealing the upper connecting pipe and the adapter;

furthermore, the upper part of the middle pipe joint is connected with the lower part of the upper pipe joint through threads, and the lower part of the middle pipe joint is connected with the upper part of the lower pipe joint through threads.

Further, all be equipped with coupling sealing washer and clamping ring between gland and the adapter, between top tube joint and well union coupling, well union coupling and the low tube coupling.

Further, the lower sealing component comprises a furnace liner flange and a furnace opening flange which are connected with each other, a furnace shell sealing gasket is arranged between the furnace liner flange and the bottom of the furnace shell, a furnace liner sealing gasket is arranged between the furnace liner flange and the furnace opening flange, and a furnace platform sealing gasket is arranged between the furnace opening flange and the furnace platform bottom plate.

The invention has the beneficial technical effects that:

(1) by adopting the heating furnace, the sealing devices are arranged at the top and the bottom of the furnace shell, so that the heating furnace can be heated in a sealed environment, and harmful effects on the environment caused by diffusion of toxic substances or radioactive substances are avoided;

(2) the heating furnace is provided with the hearth air inlet pipe, the air guide pipe and the hearth exhaust pipe, the temperature is quickly reduced through the hearth, and meanwhile, the temperature reduction speed of the furnace pipe is accelerated, so that the production efficiency is improved;

(3) the heating furnace can realize quick maintenance and replacement of parts, particularly can realize independent replacement of a radiant tube which is a service life bottleneck of the electric heating furnace, reduces maintenance cost and saves maintenance time;

(4) the heating furnace can complete heating by redistributing power under the condition that part of the radiant tubes are failed, and has good adaptability.

(5) The heating furnace provided by the invention aims at the weak link of sealing under a high-temperature condition, namely, a secondary sealing structure capable of carrying out double sealing and pressure detection is arranged between the connecting pipe at the top of the furnace pipe and the top plate of the furnace shell, so that the sealing reliability can be improved.

Drawings

FIG. 1 is a front sectional view of a furnace according to the present invention;

FIG. 2 is a top view of FIG. 1;

FIG. 3 is an enlarged view taken at A in FIG. 1;

figure 4 is a schematic view of the upper seal assembly adapter removed;

FIG. 5 is a schematic view of the structure of the radiant tube and thermocouple replacement;

FIG. 6 is a schematic structural view of furnace body replacement of the heating furnace;

FIG. 7 is a schematic view of a change in the hearth seal;

fig. 8 is a schematic structural view of the rapid cooling system.

In the figure: 1-hearth inlet pipe, 2-heat insulation block, 3-air guide pipe, 4-hearth 5-furnace pipe, 6-heating element, 7-hearth outlet pipe, 8-temperature measuring element, 9-furnace shell top plate, 10-heat insulation layer, 11-furnace shell, 12-furnace shell sealing gasket, 13-furnace pipe flange, 14-locking mechanism, 15-furnace pipe sealing gasket, 16-furnace mouth flange, 17-hearth sealing gasket, 18-gland, 19-adapter, 20-upper pipe joint, 21-middle pipe joint, 22-lower pipe joint, 23-upper connecting pipe, 24-pipe joint sealing ring, 25-pressure ring, 26-adapter sealing gasket, 27-hearth top connecting pipe

Detailed Description

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

As shown in fig. 1 and 2, the present invention is a schematic structural diagram of a heating furnace, which includes a furnace shell 11 having a lower opening and a furnace assembly inserted into the furnace shell 11, wherein the furnace assembly includes a furnace 5 and a furnace platform 4 disposed in the furnace 5 and capable of being lifted. This furnace pipe 5 is bell jar shape thin wall cavity structure, its upper portion has furnace pipe top connecting pipe 27, furnace pipe top connecting pipe 27 wears out the stove outer covering top, it is sealed through last seal assembly between furnace pipe top connecting pipe 27 and the stove outer covering roof 9, it is sealed through lower seal assembly between furnace pipe lower part periphery and the stove outer covering bottom, go up seal assembly and lower seal assembly cooperation, make the material heat under inclosed environment, avoid the diffusion of poisonous substance or radioactive substance, produce unfavorable influence to the environment. The furnace platform 4 comprises a cup seat at the top, a heat preservation block 2 at the middle part and a furnace platform bottom plate at the bottom. A plurality of heating elements 6 and a plurality of temperature measuring elements 8 which are inserted from the top of the furnace shell are arranged between the inner wall of the furnace shell 11 and the furnace pipe 5. The bottom of the furnace shell 11 is provided with a hearth air inlet pipe 1 and a plurality of air guide pipes 3, the top of the furnace shell is provided with a hearth exhaust pipe 7, and the hearth air inlet pipe 1, the air guide pipes 3 and the hearth exhaust pipe 7 form a rapid cooling system of a hearth, so that the production efficiency is improved. An insulating layer 10 is arranged between the inner wall of the furnace shell 11 and the heating element 6, so that the temperature in the furnace can be ensured conveniently. The furnace shell 11 is provided with a locking mechanism 14, the locking mechanism 14 is connected with a locking fixing piece arranged on the box chamber and used for realizing the fixation of the furnace shell, and the structure can be in a movable joint bolt form.

Wherein: the furnace pipe 5 is positioned in the middle of the furnace body and is a heat-resistant steel lower opening cavity, and the size of the cavity is matched with the furnace platform 4 arranged in the furnace body.

The lower sealing assembly comprises a furnace pipe flange 13 and a furnace opening flange 16 which are arranged on the periphery of the furnace pipe 5, and the furnace pipe flange 13 and the furnace opening flange 16 are connected through a connecting piece. A furnace shell sealing gasket 12 is arranged between the furnace liner flange 13 and the bottom of the furnace shell 11 and used for sealing the furnace shell, a furnace liner sealing gasket 15 is arranged between the furnace liner flange 13 and the furnace opening flange 16 and used for sealing the furnace liner, the furnace opening flange 16 is connected with the furnace platform bottom plate, and a furnace platform sealing gasket 17 is arranged between the furnace opening flange 16 and the furnace platform bottom plate and used for sealing the furnace platform. The furnace shell sealing gasket 12 and the furnace liner sealing gasket 15 are both high-temperature-resistant sealing materials, and materials such as silicon rubber and the like can be used.

The upper sealing assembly includes an upper connecting tube 23 and an adapter 19. The lower part of the upper connecting pipe 23 is welded with a connecting pipe 27 at the top of the furnace pipe, the upper part of the upper connecting pipe 23 is in threaded connection with the lower part of the adapter 19, sealing is realized through threaded pressing force, and an adapter sealing gasket 26 is arranged between the upper connecting pipe 23 and the adapter 19. Adapter 19 is removable cross cavity structures, including horizontal pipe and vertical pipe, and horizontal pipe is used for stove courage exhaust and the pressure measurement of stove courage, inserts the thermocouple in the vertical intraductal for to the measurement of the temperature in the stove courage and the sealed of stove courage. Adapter 19's top is equipped with gland 18, and adapter 19 and gland 18 closely cooperate, and the lower part is equipped with top tube coupling 20, well union 21 and lower union 22 in the adapter 19, and top tube coupling 20 is hollow coupling structure, and its external screw thread matches with the internal thread at well union 21 top, and well union 21 lower part is external screw thread structure, matches with the internal thread of lower union 22, and lower union 22 lower part is passed through the flange and is connected with stove outer shell roof 9. All the above groups of screw thread matching are matched through a pipe joint sealing ring 24 and a pressing ring 25, a sealing space can be formed outside the adapter 19, and a second seal is arranged, as shown in fig. 3.

The heat preservation layer 10 is arranged outside the furnace pipe 5 and inside the furnace shell 11, the bottom opening of the heat preservation layer is matched with the outer diameter of the furnace pipe in size, the heat loss of the middle part is reduced, the middle part of the heat preservation layer is concave, the top of the heat preservation layer is provided with a plurality of openings, and the specifications of the openings are matched with the upper connecting pipe, the radiant tube, the hearth exhaust pipe 7 and the thermocouple of the furnace pipe 5. The bottom of the heat insulation material 10 is provided with a plurality of mounting holes of the air guide pipes 3, and the mounting holes are matched with the air guide pipes 3. The inner material of the heat-insulating layer 10 can be alumina fiber, and the outer material is soft alumina silicate fiber.

The radiant tube is in a resistance wire form of reciprocating winding, two adjacent sections are isolated through a ceramic piece, the top of the radiant tube is in a flange structure and is connected with a furnace shell top plate 9, and an electrode leading-out terminal is arranged at the top of the radiant tube and used for electrical connection. Each radiant tube is a heating module, a plurality of groups of radiant tubes are arranged in the furnace shell, and when one radiant tube fails, other radiant tubes can still work normally to finish heating.

The thermocouple is a middle thermocouple wire, a sleeve is arranged outside the thermocouple wire, and the thermocouple wire is arranged on the furnace shell top plate 9 in a flange mounting mode.

The air guide pipe 3 is of a blind pipe structure, the side face of the top of the air guide pipe is provided with a plurality of small holes, and the small holes face the direction of the furnace pipe 5 during installation. The air guide pipe 3 is made of high-temperature resistant compact material, such as ceramic.

The furnace shell top plate 9 is a cover plate of the furnace shell and is connected with the furnace shell 11 through bolts. The furnace shell top plate is provided with a plurality of through holes, the specifications of the through holes are matched with the upper connecting pipe, the radiant tube and the thermocouple of the furnace liner, and the through holes are matched with a flange structure, so that the installation and the sealing of the parts can be realized.

The following describes how each part of the heating furnace is replaced:

1. and (6) overhauling the adapter. When needs overhaul the sealed pad 26 of adapter, or overhaul the furnace body, can loosen top tube coupling 20, and then rotate adapter 19 and can pull down the adapter and overhaul relatively. If further will overhaul secondary seal structure, can loosen well union 21, take off, can realize the maintenance to whole secondary seal structure, as shown in fig. 4.

2. Replacement of radiant tubes and thermocouples. Compared with mechanical parts such as furnace shells, heat insulation materials and the like, electrical elements such as radiant tubes, thermocouples and the like have more random failures and shorter service life, so that a more convenient and faster maintenance mode is required. The electric heating furnace adopts a structural form of mounting from the top, adopts a modular design, and only needs to loosen the screws of the fixed flange during maintenance, the damaged radiant tube and the thermocouple can be drawn out from the top and then are loaded into a new element to complete replacement. As shown in fig. 5.

3. And (5) replacing the furnace body. When the parts in the furnace body have problems or the furnace body sealing gasket needs to be overhauled, the furnace body locking mechanism 14 can be loosened to integrally draw out the furnace body, as shown in fig. 6.

4. And (4) replacing a sealing gasket of the furnace platform. The hearth seal 17 is replaced from below, and when the hearth is lowered, the hearth seal is exposed and replaced from inside the cabinet by remote inspection, as shown in fig. 7.

5. And (4) realizing forced cooling. When forced cooling is needed, cooling medium is introduced from the hearth gas inlet 1, the cooling medium is blown into the hearth between the furnace pipe and the heat insulation material through the air guide pipe 3 and is discharged from the hearth exhaust pipe 7, and the temperature in the furnace pipe can be rapidly reduced through continuous cooling medium circulation, so that the purpose of rapid cooling is achieved, as shown in fig. 8.

The heating furnace of the present invention is not limited to the above specific embodiments, and those skilled in the art can derive other embodiments according to the technical solutions of the present invention, and the embodiments also belong to the technical innovation scope of the present invention.

Claims

1. The heating furnace comprises a furnace shell (11) with a lower opening and a furnace pipe assembly arranged in the furnace shell (11) in a penetrating way, and is characterized in that: the furnace pipe assembly comprises a furnace pipe (5) and a furnace platform (4) which is arranged in the furnace pipe (5) and can be lifted, the lower periphery of the furnace pipe (5) is sealed with the bottom of a furnace shell (11) through a lower sealing assembly, a furnace pipe top connecting pipe (27) is arranged at the upper part of the furnace pipe (5), and the periphery of the furnace pipe top connecting pipe (27) is sealed with a furnace shell top plate (9) through an upper sealing assembly; a plurality of heating elements (6) inserted from the top of the furnace shell (11) are arranged between the inner wall of the furnace shell (11) and the furnace pipe (5); the bottom of the furnace shell (11) is provided with a hearth air inlet pipe (1) and an air guide pipe (3), and the top of the furnace shell (11) is provided with a hearth exhaust pipe (7); the upper sealing assembly is a secondary sealing structure which comprises an upper connecting pipe (23), an adapter (19) and a gland (18); the lower part of the upper connecting pipe (23) is welded with the upper part of a furnace pipe top connecting pipe (27), the upper part of the upper connecting pipe (23) is connected with the lower part of the adapter (19) through threads, and the upper part of the adapter (19) is connected with the gland (18) through threads; the joint between the adapter (19) and the upper connecting pipe (23) and the joint between the adapter (19) and the gland (18) are sealed by adapter sealing gaskets.

2. The heating furnace according to claim 1, wherein: a plurality of temperature measuring elements (8) inserted from the top of the furnace shell (11) are also arranged between the inner wall of the furnace shell (11) and the furnace pipe (5).

3. A heating furnace according to claim 2, wherein: the heating element (6) is a reciprocating winding radiant tube, and two adjacent sections of radiant tubes are isolated by a ceramic piece; the temperature measuring element (8) is a thermocouple.

4. The heating furnace according to claim 1, wherein: adapter (19) are cross cavity structures, including horizontal pipe and vertical pipe, horizontal pipe is used for stove courage exhaust and stove courage internal pressure measurement, insert the thermocouple in vertical intraductal for to the measurement of temperature in stove courage (5).

5. The heating furnace according to claim 4, wherein: the secondary sealing structure also comprises an upper pipe joint (20), a middle pipe joint (21) and a lower pipe joint (22) which are sequentially connected, and is used for sealing between an upper connecting pipe (23) and the adapter (19);

6. the heating furnace according to claim 5, wherein: the upper part of the middle pipe joint (21) is connected with the lower part of the upper pipe joint through threads, and the lower part of the middle pipe joint (21) is connected with the upper part of the lower pipe joint (22) through threads.

7. The heating furnace according to claim 6, wherein: and a pipe joint sealing ring and a pressing ring are arranged between the gland (18) and the adapter (19), between the upper pipe joint (20) and the middle pipe joint (21), and between the middle pipe joint (21) and the lower pipe joint (22).

8. The heating furnace according to claim 1, wherein: the lower sealing assembly comprises a furnace pipe flange (13) and a furnace opening flange (16) which are connected with each other, a furnace shell sealing gasket (12) is arranged between the furnace pipe flange (13) and the bottom of a furnace shell (11), a furnace pipe sealing gasket (15) is arranged between the furnace pipe flange (13) and the furnace opening flange (16), and a furnace platform sealing gasket (17) is arranged between the furnace opening flange (16) and a furnace platform bottom plate.