CN1157329A

CN1157329A - Hood-type annealing furnace

Info

Publication number: CN1157329A
Application number: CN 96104043
Authority: CN
Inventors: 彼得·H·埃布纳; 赫里伯特·洛克纳
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-02-16
Filing date: 1996-02-16
Publication date: 1997-08-20

Abstract

A hood-type annealing furnace comprises an annealing base for supporting the annealing goods and a protective hood tightly placed onto the annealing base. Inside the annealing base there is provided a fan including a central impeller and a distributor surrounding the same. To achieve a quicker cooling after the heat treatment, a sealable annular gap is disposed between the impeller and the distributor, behind which annular gap a heat exchanger is provided, from which the partial quantity of protective gas branched off into the annular gap can flow back into the protective hood.

Description

Bell type annealing furnace

The present invention relates to a kind of bell type annealing furnace, especially for the bell type annealing furnace of band steel or wire rod, it comprises the annealing table and the protective guard that is placed in hermetically on the annealing table that are used to support the annealing article; And in the annealing table, a blower fan that comprises a center impeller and around the divider of impeller is housed, being used to circulate is present in shielding gas in the protective guard.

In the thermal treatment of these metalloid annealing article; this thermal treatment and necessary follow-up cooling are all carried out under shielding gas; shielding gas consists predominantly of the mixture of nitrogen or hydrogen or these gases, is mainly used in to avoid on the metallic surface of annealing article oxidation taking place.In order to utilize this shielding gas, the annealing article that will be supported on the annealing table with protective guard cover, and in protective guard, after finding time or washing down process, the pump circulation of utilizing blower fan to produce is blown shielding gas to plunder the surface of annealing article.

After thermal treatment is finished, replace the heating mantles that is used for heating purposes that is placed on the protective guard with a cooling cowl, by the outside surface that makes airflow overprotection cover the material that loads is cooled off.In order to accelerate process of cooling, when reaching certain temperature, also can add entry and replace and stop cooling air flowing.After process of cooling, wash down after the process, remove cooling cowl, and mention protective guard from the annealing table with one.

Process of cooling for the material accelerating to anneal article, promptly pack into; known method is the part of the circulating current of shielding gas to be drawn into the outside from annealing table district by one or several venting ports through a water cooler of an additional blower fan, and it can be turned back to anneal chamber.But because this exterior cooling loop, the power loss that heat-processed is accompanied by by circulating current inlet mouth of shunting in process of cooling and venting port increases.In addition, since near the lubricant resistates that water cooler, evaporates, the inevitable pollution, and this need exert to safeguard.Moreover because blower fan and water cooler are installed under the annealing table, the foundation structure under this structure assembly is quite complicated.

In order to accelerate process of cooling, it also is known in the divider of annealing table the cooling tube that extends perpendicular to the blower fan axle being installed, these cooling tubes do not need in annealing process, and have only and just carry heat-eliminating medium since the process of cooling of a scheduled time.But in this case, increased the possibility that causes inefficacy owing to the crackle that produces in the tube bank.In input heat-eliminating medium and rapid refrigerative process subsequently; pipe sharply shrinks; will cause revealing in the fatigue of relatively short all after dates like this owing to material; this leakage can cause the increase of the undesirable moisture content in the round-robin shielding gas again, and even may cause by the generation oxidation of heat treated metallic surface.

Therefore the objective of the invention is to eliminate these defectives and the bell type annealing furnace that creates a kind of above-mentioned form, it can be accelerated process of cooling and not have damage or risk of pollution, and needn't provide additional space under the annealing table.

The present invention has realized this purpose, for a sealable circular clearance is provided between impeller and the divider, in its back a heat exchanger is installed in the present invention, and that part of shielding gas that therefrom is diverted in the circular clearance flow back in the protective guard.

Yes in the circular clearance in heat treatment process closes, and carries out the circulation of common whole shielding gas.But; at cooling stages, the part of protection air-flow is admitted to circular clearance and heat exchanger, promptly is cooled; and only just be added into after this in the shielding gas that remains heat, so just realized the quicker cooling of shielding gas and shortened process of cooling.This does not need extra blower fan, only needs the heat exchanger installed thereafter, and its size is less relatively, and does not require that below the annealing table very big space is arranged.When obtaining the identical effect of known exterior cooling stream, reduced technical difficulty widely.Owing to there is not extra blower fan, the danger that the lubricant residue of evaporation pollutes has not just existed yet.

Carry out incidental control simply for the closed ring gap with to the amount of shielding gas of shunting; a heat exchanger thin wall cylinder that open wide and that have a wear ring or analogue is installed in the circular clearance of downward extension, and it can utilize a setting device that is installed in annealing table outside to move this tube by a connecting rod that passes the bottom of annealing table hermetically.Utilize a temperature detection and evaluating system can regulate the tube that has wear ring, and make the unlikely performance of its latter linked heat exchanger excessive.

Between annealing table and protection case, stay a circular clearance with known mode own, so that the shielding gas recirculation of effusive that part of amount from heat exchanger.In order to provide controllability to the tube that has guard ring, each blade of divider has a groove at place, contiguous sealable circular clearance, so that hold wear ring when opening in the circular clearance.

Accompanying drawing has been represented half the axial sectional view of the basic element of character of the bell type annealing furnace of an embodiment with way of illustration.

Bell type annealing furnace comprises annealing table 1 and protective guard 3 that is placed on hermetically on the annealing table 1 of annealing article 2 that are used to support mark.In annealing table 1, provide one to include a center impeller 4 and a blower fan that is looped around its divider 5 on every side.The structure that supports annealing article 2 is not shown for the reason of simplifying.Below impeller 4 and divider 5, place a tamping unit 6 of not drawing thin portion, a heat exchanger 8 is installed in its lower section.

Between impeller 4 and divider 5, arrange a circular clearance 7; it extends downwardly into heat exchanger 8; and between annealing table and/or tamping unit 6 and annealing cover 2, also provide a circular clearance 9, make gas to flow back into the main chamber of protective guard 3 by heat exchanger 8 from circular clearance 9.A tube 11 that has a wear ring 10 is provided in the circular clearance 7 of extending downwards, it can move by a setting device 12 and a connecting rod 13 that passes the bottom of annealing table hermetically that is installed in annealing table 1 outside, make wear ring 10 closed ring gaps 7, or can be brought to different open positions.In order to form the space for wear ring 10 or tube 11, a groove 14 is arranged all on the blade of each divider 5.

In illustrated situation, promptly in cooling stages, a part of shielding gas is conveyed into circular channel 7 from blower fan 4, arrives heat exchanger 8 thus, and mixes with main flow below annealing cover 3 when finally flowing back to.

Claims

1; a kind of bell type annealing furnace; particularly a kind of annealing furnace that is used to steel or wire rod; it comprises the annealing table (1) and the protective guard (3) that will be placed on hermetically on the annealing table (1) that are used for supporting annealing article (2); inside at annealing table (1) provides a blower fan that comprises a center impeller (4) and a divider around it (5); being used for circulation is present in shielding gas in the protective guard (3); it is characterized in that; between impeller (4) and divider (5), be provided with a sealable circular clearance (7); provide a heat exchanger (8) in the back of this circular clearance, the shielding gas that is diverted to the part amount in the circular clearance (7) thus flow back in the protective guard (3).

2, bell type annealing furnace as claimed in claim 1, it is characterized in that, in the circular clearance (7) of extending, settle a thin wall cylinder (11) downwards, its heat exchanger (8) is opened wide and is had a wear ring (10) or an analogue, and can be installed in the setting device (12) of annealing table (1) outside and by a connecting rod (13) that passes the bottom of annealing table (1) hermetically it is moved by one.

3, bell type annealing furnace as claimed in claim 1 is characterized in that, the circular clearance (9) that is located in a manner known way between annealing table (1) and the protective guard (3) is used for the shielding gas of recirculation from that part of amount of heat exchanger (8) discharge.

4, bell type annealing furnace as claimed in claim 1 or 2 is characterized in that, each blade of divider (5) all has a groove (14) near sealable circular clearance, is used for that (7) hold wear ring (10) when opening in the circular clearance.