CN201471067U - Novel longhole pipe sheet welding gun - Google Patents

Abstract

The utility model relates to a novel longhole pipe sheet welding gun for welding a double-pipe plate heat exchanger for manufacturing polysilicon. The novel longhole pipe sheet welding gun comprises a gun pipe (13) in which an air inlet pipe (1) and a water inlet pipe (2) are inserted. The novel longhole pipe sheet welding gun is characterized in that: an insulating ring (5) is sheathed at the outer end of the gun pipe (13); an outer positioning sleeve (6) is sheathed out of the insulating ring (5); an inner positioning core (8) is sheathed at the inner end of the gun pipe (13); the inner end of the inner positioning core (8) is connected with a ceramic nozzle (11) which is made of silicon nitride and is internally provided with a conductive nozzle (9); the conductive nozzle (9) is fixedly connected with a tungsten bar (10) which is arranged vertical to the gun pipe (13); and a thermoplastic pipe (7) is sheathed on the pipe wall of the gun pipe (13) between the outer positioning sleeve (6) and the inner positioning core (8). The novel longhole pipe sheet welding gun can ensure the capsulation and intensity of the heat exchange pipe and the inner pipe plate by welding.

Description

Novel deep hole tube sheet welding gun

(1) technical field

The utility model relates to a kind of novel deep hole tube sheet welding gun.Be used to make the welding of the double tube plate heat exchanger of polysilicon.Belong to technical field of welding equipment.

(2) background technology

Along with the continuous aggravation of energy crisis, environmental problem, a large amount of research has been carried out to regenerative resource in countries in the world.Solar energy becomes the focus that everybody is paid close attention to its environmental protection, high reserves, safe and potential economy.Polysilicon is the critical materials of photovoltaic and electronic industry, and along with the fast development of international solar energy industry, huge breach appears in the market demand, becomes " bottleneck " of photovoltaic industry development.According to statistics, world's solar cell power generation probably accounted for 1 ‰ of total energy in 2010, needed 130,000 tons of solar-grade polysilicons.Solar cell becomes a kind of development trend as a kind of clean energy resource, so the polysilicon market prospects are boundless.And the double tube plate heat exchanger (see figure 1) is to make the nucleus equipment of polysilicon.Double tubesheet generally all adopts expanded joint (machinery expands or hydraulic pressure expands) method to guarantee sealing, but often be subjected to the influence of the factors such as diameter, thickness and U type pipe of pipe at present.Pipe diameter is more little, and the pipe wall thickness is thick more, just difficult more enforcement of expanded joint, and separate space cylindrical shell long (reaching 500mm) is difficult for expanded joint, and risk is bigger.And leak easily behind the expanded joint, bring massive losses will for polysilicon enterprise in case leak, media such as trichlorosilane and silicon tetrachloride are inflammable and explosive.Consider to solve this difficult problem from the angle of welding for this reason.

And common argon-arc welding gun is because the restriction of space and position and can not realize welding, satisfies requirement of welding so can only consider that Butt welding gun redesigns.

(3) summary of the invention

The purpose of this utility model is to overcome above-mentioned deficiency, provides a kind of and can guarantee the sealing of heat exchanger tube and internal tube plate and the novel deep hole tube sheet welding gun of intensity by welding.

The purpose of this utility model is achieved in that a kind of novel deep hole tube sheet welding gun, comprise gun barrel, be inserted with air inlet pipe and water inlet pipe in the gun barrel, the gun barrel outer end is set with dead ring, dead ring is equipped with the outside fix cover outward, location core in gun barrel the inner is set with, interior location in-core end is connected with ceramic nozzle, ceramic nozzle adopts silicon nitride material, be provided with ignition tip in the ceramic nozzle, be fixedly connected with tungsten bar on the ignition tip, this tungsten bar and described gun barrel are arranged vertically, and are set with thermoplastic tube on the gun barrel tube wall between described outside fix cover and the interior location core.

Owing to weld from inside tube, at first to adjust the position of tungsten bar, guarantee to make tungsten bar perpendicular to pipe, electric arc is penetrated on tube wall during welding.

Usually the fusion penetration of argon arc welding shallow (≤3mm), so heat exchanger tube and internal tube plate can not be fused together, so, be coated with the last layer activating agent in tube inner wall in order to increase the fusion penetration of welding.Activating agent mainly is made up of oxide (SiO2, Cr2O3 and TiO2) and fluoride (CaF2 and NaF), utilizes acetone that the graininess activating agent is stirred, and spreads upon the inner surface of heat exchanger tube more uniformly.Activating agent evaporates the back and is enclosed in the electric arc neighboring area with the atom form under high arc temperature, because electric arc neighboring area temperature is lower, the electronics that the activating agent evaporation atom is caught in this zone forms anion and is lost to surrounding space, make the electron number in the electric arc present minimizing trend, the electric arc electric conductivity weakens, its final result causes electric arc to produce contraction automatically, and heat is concentrated, arc force is concentrated, thereby welding penetration is increased.Utilize activating agent to increase the fusion penetration of weld seam during welding, heat exchanger tube and tube sheet are fused together fully.

Because be subjected to the restriction (φ 19X2, φ 19X3) of pipe diameter, the diameter of welding gun will be much smaller than the internal diameter of heat exchanger tube.Because welding gun itself adopts metallic cavity to need effects such as water flowing, ventilation, conduction.And the distance that welding gun enters behind the pipe and between the tube wall is very little, is punctured by high-frequency electrical easily during welding, so need insulate non-conductive at the outer surface of welding gun.The space is narrow and small in the heat exchanger tube, will produce high heat during welding.General temperature is about 1500 ℃, and conventional insulator will melt, and especially at ceramic nozzle, melts easily and ftractures.At this problem, adopt silicon nitride material, molecular formula is that Si3N4 is used as structural ceramic material, and this material is heated in air more than 1000 ℃, and sharply cooling sharply heating can be not cracked more yet.Silicon nitride usually under normal pressure 1900 ℃ begin to decompose.Utilized carrying out smoothly that this character high temperature resistant, insulation of silicon nitride guarantees to weld, and be difficult for being punctured by high-frequency electrical; The electric arc environment temperature reaches about 1500 ℃ during welding, and ceramic nozzle is not melted; Having welded the back is cooled to also can not ftracture about 200 ℃ in air immediately.

The beneficial effects of the utility model are:

Utilize activating agent that the heat that argon arc welding produces is concentrated when 1, welding, increase the fusion penetration of weld seam.

2, the silicon nitride ceramics nozzle has solved the frangible problem easy to crack of ceramic nozzle in the welding process, solves the high-frequency arc strike problem.

The utility model has solved the means that double tube plate heat exchanger adopts expanded joint for a long time always, guarantees the sealing and the intensity of heat exchanger tube and internal tube plate by welding.The utilization of welding method has solved the potential safety hazard of double tubesheet product for a long time.

(4) description of drawings

Fig. 1 is the expanded joint of double tubesheet employing in the past schematic diagram.

Fig. 2 is the novel deep hole tube sheet welding gun schematic diagram of the utility model.

Fig. 3 is the utility model deep hole tube sheet welding schematic diagram.

Fig. 4 is an internal tube plate welding of the present utility model back profile.

Among the figure:

Air inlet pipe 1, water inlet pipe 2, outlet pipe 3, brass contiguous block 4, dead ring 5, outside fix cover 6, thermoplastic tube 7, interior location core 8, ignition tip 9, tungsten bar 10, ceramic nozzle 11, tungsten bar set bolt 12, gun barrel 13, expanded joint position 14, outer tube plate 15, heat exchanger tube 16, internal tube plate 17.

(5) specific embodiment

Referring to Fig. 2, the novel deep hole tube sheet welding gun that the utility model relates to, comprise gun barrel 13, be inserted with air inlet pipe 1 and water inlet pipe 2 in the gun barrel 13, gun barrel 13 outer ends are connected with outlet pipe 3, outlet pipe 3 outer ends are connected with brass contiguous block 4, gun barrel 13 outer ends are set with dead ring 5, the dead ring 5 outer outside fix covers 6 that are equipped with, location core 8 in gun barrel 13 the inners are set with, core 8 the inners, interior location are connected with ceramic nozzle 11, be provided with ignition tip 9 in the ceramic nozzle 11, be fixedly connected with tungsten bar 10 with tungsten bar set bolt 12 on the ignition tip 9, this tungsten bar 10 is arranged vertically with described gun barrel 13, is set with thermoplastic tube 7 on gun barrel 13 tube walls between described outside fix cover 6 and the interior location core 8.

Earlier activating agent is spread upon the heat exchanger tube inwall during welding, more whole welding gun is extend in the heat exchanger tube after the acetone volatilization in the isoreactivity agent.Internal diameter and external diameter by heat exchanger tube are located, and the outside fix cover on the welding gun contacts with inwall with the outer wall of heat exchanger tube respectively with interior location core, guarantee that welding gun and heat exchanger tube are on same center line.Can guarantee in the weld period arc length so even, under the situation about not changing the welding one week.Fusion penetration when activating agent increases welding, the special substance of ceramic nozzle do not split when guaranteeing welding guarantees that high-frequency arc strike does not take place in other place.Thereby that guarantees to weld carries out smoothly, specifically sees Fig. 3.Internal tube plate welding back profile such as Fig. 4.

Claims (1)

1. novel deep hole tube sheet welding gun, comprise gun barrel (13), be inserted with air inlet pipe (1) and water inlet pipe (2) in the gun barrel (13), it is characterized in that: described gun barrel (13) outer end is set with dead ring (5), the outer outside fix cover (6) that is equipped with of dead ring (5), location core (8) in gun barrel (13) the inner is set with, core (8) the inner, interior location is connected with ceramic nozzle (11), ceramic nozzle (11) adopts silicon nitride material, be provided with ignition tip (9) in the ceramic nozzle (11), be fixedly connected with tungsten bar (10) on the ignition tip (9), this tungsten bar (10) is arranged vertically with described gun barrel (13), is set with thermoplastic tube (7) on gun barrel (13) tube wall between described outside fix cover (6) and the interior location core (8).

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