CN88201516U

CN88201516U - Electron gun for electron-bombardment oven beam furnace

Info

Publication number: CN88201516U
Application number: CN 88201516
Authority: CN
Inventors: 廖志秋
Original assignee: Beijing General Research Institute for Non Ferrous Metals
Current assignee: Beijing General Research Institute for Non Ferrous Metals
Priority date: 1988-03-15
Filing date: 1988-03-15
Publication date: 1988-11-09

Abstract

The utility model relates to an electron gun for electron-bombardment oven beam furnaces for metal refining or remelting, which is composed of an electron generating chamber and a drifting chamber. A shielding cover is installed out of the tungsten cathode of the electron generating chamber to make the tungsten cathode, a cathode block and an electrode external cylinder separated, and simultaneously the structure of the cathode block is simplified; the cathode block is placed on a beam forming electrode through three points. A fence pore plate, a drifting tube and a milliammeter are grounded and are insulated with a furnace shell after being mutually connected. Because of the improvement, the utility model has the advantages of low power consumption and high efficiency. The lifetime of the tungsten cathode and the cathode block is observably enhanced, the installation of the cathode block is simplified, and the tracks of the electron beam can be controlled at any time.

Description

Electron gun for electron-bombardment oven beam furnace

The utility model relates to the electron beam gun of the electron bombardment furnace that refining of metal or remelting use.

The electron bombardment furnace that is used for refining of metal or remelting: be mainly used in the melting and casting of the particularly various refractory metals of metal such as tungsten, molybdenum, tantalum, niobium, titanium, zirconium, hafnium and alloy thereof and iron and its alloy, the technological operations such as welding of large-scale superconduction copper-clad cover.The formation of electron bombardment furnace comprises that electron beam gun, feeding device, crucible, furnace shell, vacuum system and power unit, its groundwork principle are to get on raw material and the molten bath by electron beam gun emission high-velocity electron beam, make raw materials melt splash into crucible, move down the cast metals that forms after the melting gradually.Electron beam gun mainly is made of electronics generation chamber (16) and drift chamber (17).Present used focused electron rifle, as the used electron beam gun of 200KW focused electron electron-beam furnace, its electronics generation chamber mainly comprises electrode inner core (1), be installed in the incense coil shape tungstencathode (2) of electrode inner core lower end, the electrode urceolus (3) that separates with insulating material and fuse with electrode inner core (1), be positioned at the cathode block (4) under the tungstencathode (2), bunching electrode under the cathode block (5), supporting base of bunching electrode (6) and accelerating anode (7), on the electrode inner core, apply 10～20 volts of alternating-current and 2.3 ten thousand volts of negative direct current high voltages, on the electrode urceolus, apply 20,000 volts of negative direct current high voltages, cathode block, bunching electrode, be in same negative high voltage current potential with the electrode urceolus, tungstencathode outside surface under the alternating-current effect produces thermionic electron beam, and by the potential difference emitting electrons bombarding cathode piece between electrode inner core and electrode urceolus, make the cathode block generating surface produce thermoelectron, by bunching electrode the cathode block ejected electron is gathered and to be passed the accelerating anode hole and quicken to enter the drift chamber, the drift chamber is by hurdle orifice plate (10), drift pipe (12) and magnetic lens (13) are formed.Because mutual repulsive force disperses the electronics trend between electronics, the effect of drift chamber is that the magnetic field size of regulating magnetic lens (13) reassembles electronics, the drift chamber of present electron bombardment furnace, all naked, electronics are got to these positions and ground connection between its drift pipe (12), hurdle orifice plate (10), furnace shell (15) and magnetic lens (13), the track of electron beam can't be adjusted and influence on request, the changing conditions of electron beam circulation efficient can not be seen at any time.Though hurdle orifice plate that has and furnace shell insulation, but still the difficult track of grasping electron beam, the situation that can't grasp whole electron beam trace and electron loss changes.Above-mentioned electron beam gun has several than significant disadvantages: between (1) tungstencathode, cathode block and electrode urceolus potential difference is arranged, tungstencathode has portions of electronics to the low electrode urceolus emission of current potential; Temperature was very high when (2) tungstencathode and cathode block were worked, and heat loss through radiation is fast, and watt consumption is big; (3) can't correctly adjust and influence the track of electron beam; (4) cathode block complex structure, the structure of the external cathode block that uses and installation roughly have three kinds of patterns, shape shown in Figure 1, there is stud the centre, upwards cathode block is installed, make middle part and both sides heating condition different, influence the negative electrode tantalum piece inequality of being heated, cathode block shown in Figure 2 will insert the tantalum piece of upwards slinging in the negative electrode tantalum piece hole with suspension rod, not only installs complicated, tantalum piece thickness is also inhomogeneous, it is inhomogeneous also to cause the tantalum piece to be heated, and the cathode block two sides of Fig. 3 is cambered surface, and it is more even to be heated, but still the installation of will upwards slinging, complicated operation; (5), make this electron beam gun, the electron beam gun of using as 200KW focused electron stove because above-mentioned shortcoming, its cathode block life-span is too short, is 80-200 hour, and cathode block boosting consumed power is bigger, be about 4KW, and the circulation efficiency of electron beam is about 90%, also awaits further raising.

One of the purpose of this utility model is to design a kind of new electron beam gun, overcomes the shortcoming of existing electron beam gun, reduces the watt consumption of electron beam gun, improves the circulation efficiency of electron beam;

Another purpose of the present utility model is the life-span that will improve tungstencathode and cathode block, simplifies the structure of rifle, makes tungstencathode and cathode block be convenient to install.

The 3rd purpose of the utility model is to want to grasp the track of electron beam at any time, so that correctly adjust the controlling electron beam track.

The electron beam gun of the said electron bombardment furnace of the utility model is made of electronics generation chamber (16) and coupled drift chamber (17).The electronics generation chamber comprises electrode inner core (1), be installed in the incense coil shape tungstencathode (2) of electrode inner core (1) lower end, the electrode urceolus (3) that separates and be connected with insulating material with the electrode inner core, be positioned at the cathode block (4) under the tungstencathode (2), bunching electrode under the cathode block (5), the supporting base (6) of bunching electrode (5) and accelerating anode (7), tungstencathode has been installed a shielding case (8) outward, shielding case (8) is installed on the electrode inner core (1), idiostatic with the electrode inner core, tungstencathode (2) and electrode urceolus (3) are separated, prevent electron emission to the electrode urceolus, the metallic support rod (9) more than three or three is arranged on the cathode block, by support rod cathode block is dropped on the bunching electrode, install very easyly, and contact area is little, and thermosteresis is little.On electrode inner core (1), apply alternating-current and negative direct current high voltage, on the electrode urceolus, apply and be lower than the galvanic negative direct current high voltage of electrode inner core, cathode block (4), bunching electrode (5), all be in same negative high voltage current potential with electrode urceolus (3), tungstencathode energising generating surface produces thermoelectron, bombards raw material and molten bath by focusing on, quickening through the drift chamber.

For the ease of going up tungstencathode is installed at electrode inner core (1), tungstencathode (2) two ends can be inserted respectively in two holes of electrode inner core (1), and fix with screw, the features simple structure such as welding that this mode is used are more at present easily gone, and very easily change tungstencathode simultaneously.

It evenly is the important factor of the even emitting electrons of cathode block that cathode block thickness keeps, and the utility model is curved surface up and down, and keeps consistency of thickness between two curved surfaces.

In order to control and adjust the track of electron beam, must know that then electron beam passes through behind the hole, hurdle electron scattering to the degree of drift chamber pipe (12), for this reason, hurdle orifice plate (10) fused with drift pipe (12) and the back ground connection that links to each other with milliampere meter, but hurdle orifice plate (10), drift pipe (12) and magnetic lens (13) must be insulated with insulating material (14) and furnace shell (15), could pass through milliampere meter (14) and adjust the track of electron beam, when the milliampere meter indication approached zero, the expression electron beam was concentrated and is got on raw material and the molten bath.

Advantage of the present utility model is:

(1) owing to increased shielding case, reduced the radiation heat loss of tungstencathode and cathode block;

(2) owing to increased shielding case, tungstencathode and cathode block can not be concentrated and be transmitted in cathode block again to the higher electrode urceolus emitting electrons of current potential, make the cathode block temperature even, thereby have reduced cathode block boosting watt consumption, improve the cathode block life-span;

(3) owing to increased shielding case, electrode urceolus positive ion bombardment tungstencathode and cathode block have been prevented, the life-span of having improved tungsten filament electrode and cathode block.

(4) cathode block is to be bearing on the bunching electrode with three (or more than three) metal support poles, and conductive heat loss is minimum, and the cathode block temperature is easy to evenly, and is easy to loading and unloading.

(5) because hurdle orifice plate and drift pipe are connected earlier behind the milliampere meter ground connection and hurdle orifice plate drift pipe and furnace shell insulate, can grasp the track and the electron loss situation of electron beam at any time, electron beam trace is adjusted in indication according to milliampere meter, more helps reducing the watt consumption of stove;

(6) owing to increased shielding case, hurdle orifice plate and drift pipe coupling milliampere meter, improved the whole efficiency of stove, as 200KW focused electron electron-beam furnace cathode block boosting consumed power only is 1.5KW, original 4KW has reduced by 62.5%, and electron beam circulation efficient is brought up to more than 98% by original 90%, and the cathode block life-span also is improved largely, bring up to more than 2000 hours by original 80-200 hour, the life-span improve at least 7-20 doubly more than.

Fig. 1,2,3: the structure of the external cathode block that uses

Fig. 4: the electron beam gun of the said electron bombardment furnace of the utility model.

Claims

1, the electron beam gun of electron bombardment furnace is formed by connecting by electronics generation chamber and drift chamber, and the electronics generation chamber comprises and applies negative direct current high voltage electricity and the electrode inner core that exchanges low voltage ⁽¹⁾, be fixed on the electrode inner core ⁽¹⁾The incense coil shape tungstencathode of lower end ⁽²⁾, imposing than the electrode inner core is the electrode urceolus of high negative direct current high voltage electricity ⁽³⁾, the insulation between electrode inner core and the electrode urceolus is positioned at the cathode block under the tungstencathode ⁽⁴⁾, cathode block ⁽⁴⁾Under bunching electrode ⁽⁵⁾, the supporting base under the bunching electrode ⁽⁶⁾With the accelerating anode that is positioned under the supporting base ⁽⁷⁾, cathode block, bunching electrode, supporting base all are in identical current potential with the electrode urceolus, and the drift chamber is positioned at electronics generation chamber below and is connected with the electronics generation chamber, comprises the hurdle orifice plate ⁽¹⁰⁾, the drift pipe under the hurdle orifice plate ⁽¹²⁾, be positioned at the outer magnetic lens of drift pipe ⁽¹³⁾, the hole on the hurdle orifice plate ⁽¹¹⁾Aim at the cathode block on it, it is characterized in that:

1) at tungstencathode ⁽²⁾Have outward tungstencathode and electrode urceolus ⁽³⁾The shielding case that separates ⁽⁸⁾, shielding case ⁽⁸⁾Be installed in the electrode inner core ⁽¹⁾On;

2) metallic support rod that (comprises three) more than three with the cathode block all-in-one-piece is arranged on the cathode block ⁽⁹⁾, be bearing in bunching electrode ⁽⁵⁾On.

2,, it is characterized in that two terminations of tungstencathode (2) are inserted in the hole of electrode inner core, and be screwed according to the electron beam gun of the said electron bombardment furnace of claim 1.

3,, it is characterized in that the upper and lower surface of cathode block (4) is curved surface and makes cathode block thickness even according to the electron beam gun of the said electron bombardment furnace of claim 2.

4,, it is characterized in that drift pipe (12) is linked to be integral body with hurdle orifice plate (10) and be connected back ground connection that drift pipe, hurdle orifice plate and magnetic lens (13) are insulated with furnace shell (15) with milliampere meter according to the electron beam gun of the said electron bombardment furnace of claim 3.