CN204007095U - High-accuracy electric heating nitriding furnace - Google Patents

Abstract

The utility model discloses a kind of high-accuracy electric heating nitriding furnace, comprise masonry in body of heater and stove, fire door, bell, in stove, nitrogen is carried and temperature equalization system, electric heating system, air-supply and smoke evacuation system, DCS control system; Body of heater is inside and outside double-layer frame structure, and between inside and outside framework, gap arranges; In stove, nitrogen conveying and temperature equalization system comprise the nitrogen transfer passage being opened in masonry side wall interlayer, uniformly be opened in the nitrogen outlet that masonry side wall inner surface communicates with nitrogen transfer passage, be horizontally fixed on the high-speed jet nozzles with injector on masonry side wall top, electric heating system has hollow water-cooled passage by Elema electrical heating elements and being arranged on electrode in housing sidewall forms; Air-supply and smoke evacuation system comprise air-supply passage and the discharge flue in masonry side wall interlayer.The utility model advantage is scientific and reasonable for structure, has greatly improved the uniformity of nitrogen and the uniformity of temperature in stove, and in stove, nitridation reaction control accuracy is high.

Description

High-accuracy electric heating nitriding furnace

Technical field

The utility model relates to industrial nitriding furnace, especially relates to high-accuracy electric heating nitriding furnace.

Background technology

Silicon nitride products based on silicon carbide is produced and must in high-temperature vacuum nitriding atmosphere stove, have been burnt till, and high temperature, high vacuum, highly purified nitrogenize environment, high accuracy Precise control mode are directly determining performance and the production cost of product quality.At present, state, the inside and outside nitrogenize firing furnace volume generally adopting, all at 4～8 cubic metres, exist production efficiency low, the deficiency that unit product power consumption is high.Because seal approach is undesirable, vacuum does not reach, and makes the purity of nitrogen just be difficult to ensure, product nitrogen rate is low.Meanwhile, because goods in the sintering process of silicon nitride goods are more responsive to environmental condition, particularly nitrogen gas concn, temperature, pressure influence maximum.Nitridation reaction is the process of heat release, and temperature is high can promote nitridation reaction aggravation, but too fast nitridation reaction release heat also can cause goods to burn out, and therefore needs effective control device, guarantees mild and stable the carrying out of goods course of reaction.In process of production except completing shove charge-heating-sealing schedule, also should carry out gas displacement operation according to nitridation reaction speed vacuumize-inflated with nitrogen repeatedly, the mode of production is and manually carries out by rule of thumb control operation at present, has the problems such as furnace inner environment control accuracy is low, and quality fluctuation is large.

Summary of the invention

The utility model object is to provide a kind of high-accuracy electric heating nitriding furnace.

For achieving the above object, the utility model is taked following technical proposals:

High-accuracy electric heating nitriding furnace described in the utility model, comprises masonry in body of heater and stove, fire door, bell, and in stove, nitrogen is carried and temperature equalization system, electric heating system, air-supply and smoke evacuation system, DCS control system; Described body of heater is inside and outside double-layer frame structure, the upper shed shell structure that described outer framework is made up of shaped steel, on the sidewall of described upper shed housing, offering stove car imports and exports, described bell, fire door are slidably matched with upper shed and the stove car import and export sealing of described housing respectively, are provided with the vacuum lead with its intracavity inter-connection on the sidewall of housing; The kiln body of described internal layer framework for being formed by steel structure support and masonry fixed thereon, the kiln body sidewall of importing and exporting position corresponding to described stove car offers stove vehicle passage mouth; Between described inside and outside framework, gap arranges; In described stove, nitrogen conveying and temperature equalization system comprise: be opened in the nitrogen transfer passage in described masonry side wall interlayer, uniformly be opened in the nitrogen outlet that masonry side wall inner surface communicates with described nitrogen transfer passage, be horizontally fixed on multiple high-speed jet nozzles with injectors on masonry side wall top, described multiple high-speed jet nozzles with injector air inlets and nitrogen transfer passage are all communicated with outside source nitrogen by pipeline; Described electric heating system is by the Si-Mo rod or the Elema electrical heating elements that are arranged on vertically downward on masonry roof, and is arranged on the electrode composition in described housing sidewall with hollow water-cooled passage in wedge-type seal mode; Described air-supply and smoke evacuation system comprise air-supply passage and the discharge flue of building by laying bricks or stones in described masonry side wall interlayer, described air-supply passage, discharge flue extend outside body of heater by seal for pipe joints respectively, and the air outlet of air-supply passage, the smoking mouth of discharge flue are opened in respectively the upper and lower of masonry side wall inner surface.

Sealing between upper shed, the import and export of stove car of described fire door, bell and described outer framework adopts respectively dual lip seal configuration; Described air-supply passage is built by laying bricks or stones in the interlayer of described masonry side wall top, and described discharge flue is built by laying bricks or stones in the interlayer of described masonry side wall bottom.

The utility model advantage is scientific and reasonable for structure, has greatly improved the uniformity of nitrogen and the uniformity of temperature in stove, and in stove, nitridation reaction control accuracy is high.

Brief description of the drawings

Fig. 1 is structural representation of the present utility model.

Fig. 2 is that the I-I of Fig. 1 is to cutaway view.

Detailed description of the invention

As shown in Figure 1, 2, high-accuracy electric heating nitriding furnace described in the utility model, comprise masonry 1 in body of heater and stove, fire door 2, bell 3, in stove, nitrogen is carried and temperature equalization system, electric heating system, air-supply and smoke evacuation system, DCS control system (DistributedControlSystem, scattered control system or Distributed Control System); Described body of heater is inside and outside double-layer frame structure, upper shed housing 4 structures that described outer framework is made up of shaped steel, on the sidewall of described upper shed housing 4, offer stove car and import and export 5, described bell 3, fire door 2 are imported and exported 5 with upper shed, the stove car of described housing 4 and are adopted respectively dual lip packing mode to be slidably matched, and are provided with the vacuum lead 16 with its intracavity inter-connection on the sidewall of housing 4; The kiln body of described internal layer framework for being formed by steel structure support 6 and masonry 1 fixed thereon, the kiln body sidewall of importing and exporting 5 positions corresponding to described stove car offers stove vehicle passage mouth 7; Between described inside and outside framework, gap arranges; In described stove, nitrogen conveying and temperature equalization system comprise: be opened in the nitrogen transfer passage 8 in described masonry 1 side wall interlayer, uniformly be opened in the nitrogen outlet that masonry 1 side wall inner surface communicates with described nitrogen transfer passage 8, be horizontally fixed on multiple high-speed jet nozzles with injectors 9 on masonry 1 side wall top, the conveyance conduit 17 of described multiple high-speed jet nozzles with injector 9 air inlets and nitrogen transfer passage 8 is all communicated with outside source nitrogen; Described electric heating system is by the Si-Mo rod or the Elema electrical heating elements 10 that are arranged on vertically downward on masonry 1 roof, and is arranged on the electrode 11 on described housing 4 sidewalls with hollow water-cooled passage in wedge-type seal mode and forms; Described air-supply and smoke evacuation system comprise the air-supply passage 12 of building by laying bricks or stones in described masonry 1 side wall top interlayer and the discharge flue 13 in the interlayer of bottom, and the air outlet of described air-supply passage 12, the smoking mouth of discharge flue 13 are opened in respectively the upper and lower of masonry 1 side wall inner surface; Air-supply passage 12, discharge flue 13 extend outside body of heater by air supply duct 14, smoke discharging pipe 15 sealings respectively, the air supply duct 14 extending outside body of heater is communicated with the blast orifice of air blast by the electrically-controlled valve by the control of described DCS control system, and the smoke discharging pipe 15 extending outside body of heater is communicated with the suction opeing of air exhauster by the electrically-controlled valve by the control of described DCS control system.

The utility model operation principle is summarized as follows:

1, body of heater adopts inside and outside double-layer frame structure, outer framework is made up of shaped steel, has therefore improved body of heater and bear the ability of furnace chamber internal pressure; Between inside and outside double-layer frame, gap arranges, and guarantees that masonry 1 is not subject to the impact of kiln body steel construction distortion, is conducive to moisture in masonry 1 simultaneously and discharges and reduce the effect of furnace body shell 4 temperature.

2, fire door 2 and bell 3 need to often carry out open and close operation, and fire door 2, bell 3, except meeting self higher intensity, also will ensure that sealing could realize the environmental requirement of the high pressure high vacuum in stove; Fire door 2, bell 3 are imported and exported 5 with upper shed, the stove car of housing 4 and are adopted dual lip slipper seal structure, even if ensured that fire door 2, bell 3 also can reach positive/negative-pressure sealing in slight deformation situation.

3, uniformity and the uniformity of goods reaction in stove, need to lean on the uniformity of nitrogen and the uniformity of temperature to ensure.To the nitrogen sending in stove, first be preheating to high temperature through the nitrogen transfer passage 8 in masonry 1 interlayer in stove, then deliver to around goods by the nitrogen outlet that is uniformly distributed in masonry 1 side wall surface, avoid low temperature nitrogen to pour in affecting the inhomogeneous of the low and atmosphere of local temperature, cause the inconsistent of course of reaction.Adopt high-speed jet nozzles with injector 9 taking nitrogen as disturbance medium, the stream of nitrogen gas of high velocity jet is taken near heat electrical heating elements 10 heaters that are arranged on masonry 1 side wall to place away from heater as the bottom of goods, multiple high-speed jet nozzles with injectors 9 form airstream in kiln circulation loop, drive the even of the interior atmosphere of furnace chamber and temperature.

4, nitriding furnace adopts Si-Mo rod and Elema to heat, power is very large, passes into the electric current maximum number kilo-ampere in stove, therefore adopts the electrode 11 with hollow water-cooled passage, electrode 11 is arranged on described housing 4 sidewalls in wedge-type seal mode, and sealing property is reliable.

5, the process of air-supply smoke evacuation is by the flue gas in the wind displacement stove outside stove, because the air temperature outside stove is lower, pass into and in stove, can cause that local temperature is too low is unfavorable for that impurity gets rid of, therefore first the wind from air supply duct 14 entered to the interior preheating of air-supply passage 12 of building by laying bricks or stones in masonry 1 side wall top interlayer, the cold air entering in kiln body is down to minimum on the impact of goods.Discharge flue 13 is built by laying bricks or stones in masonry 1 side wall bottom interlayer, multiple smokings mouthful uniform bottom that is opened in masonry 1 side wall inner surface, described DCS control system is by the analytical calculation to draft, adjust each smoke mouthful size equalization kiln in draft, guarantee away from smoke mouthful local flue gas can extract out.

6, DCS control system is burnt till and is carried out process control kiln, centralized operation, and decentralised control, differentiated control, flexible configuration, control accuracy is high.By design of Configuration Software, realize friendly human-machine interface, carry out computing for important data as three line degrees of unbalancedness, reaction rate etc., for operation and judgement provide reliable reference frame.Build energy management system, the energy consumption of kiln being burnt till to overall process monitors, for the optimization of technique provides reference simultaneously.

7, after flue gas is drawn by high temperature air exhauster, enter a heat-exchange system and add hot-air, the clean hot air after heat exchange is dry for goods base substrate.Flue gas after heat exchange is by secondary heat exchange system heating water, and the water after heating, for workman's bathing, is realized the efficient utilization of waste heat.

Claims (2)

1. a high-accuracy electric heating nitriding furnace, comprises masonry in body of heater and stove, fire door, bell, and in stove, nitrogen is carried and temperature equalization system, electric heating system, air-supply and smoke evacuation system, DCS control system; It is characterized in that: described body of heater is inside and outside double-layer frame structure, the upper shed shell structure that described outer framework is made up of shaped steel, on the sidewall of described upper shed housing, offering stove car imports and exports, described bell, fire door are slidably matched with upper shed and the stove car import and export sealing of described housing respectively, are provided with the vacuum lead with its intracavity inter-connection on the sidewall of housing; The kiln body of described internal layer framework for being formed by steel structure support and masonry fixed thereon, the kiln body sidewall of importing and exporting position corresponding to described stove car offers stove vehicle passage mouth; Between described inside and outside framework, gap arranges; In described stove, nitrogen conveying and temperature equalization system comprise: be opened in the nitrogen transfer passage in described masonry side wall interlayer, uniformly be opened in the nitrogen outlet that masonry side wall inner surface communicates with described nitrogen transfer passage, be horizontally fixed on multiple high-speed jet nozzles with injectors on masonry side wall top, described multiple high-speed jet nozzles with injector air inlets and nitrogen transfer passage are all communicated with outside source nitrogen by pipeline; Described electric heating system is by the Si-Mo rod or the Elema electrical heating elements that are arranged on vertically downward on masonry roof, and is arranged on the electrode composition in described housing sidewall with hollow water-cooled passage in wedge-type seal mode; Described air-supply and smoke evacuation system comprise air-supply passage and the discharge flue of building by laying bricks or stones in described masonry side wall interlayer, described air-supply passage, discharge flue extend outside body of heater by seal for pipe joints respectively, and the air outlet of air-supply passage, the smoking mouth of discharge flue are opened in respectively the upper and lower of masonry side wall inner surface.

2. high-accuracy electric heating nitriding furnace according to claim 1, is characterized in that: the sealing between upper shed, the import and export of stove car of described fire door, bell and described outer framework adopts respectively dual lip seal configuration; Described air-supply passage is built by laying bricks or stones in the interlayer of described masonry side wall top, and described discharge flue is built by laying bricks or stones in the interlayer of described masonry side wall bottom.