CN104496153A - Device and method for preventing crystallization at leakage hole - Google Patents

Abstract

The invention discloses a device and a method for preventing crystallization at a leakage hole, belonging to the technical field of manufacturing of optical glass, and mainly solving the problem that crystallization is often caused due to extremely low temperature at the leakage hole in the process of molding the optical glass. The device is mainly characterized in that each folding part of the lower part of each semicircular-folding platinum heating piece is level to a leakage orifice; the lower ends of the inner sides of two semicircular folding platinum heating pieces are respectively welded on the lower edge of the leakage orifices in two sides of a leakage pipe; two electrode plates are respectively welded on the outside edges of the two semicircular folding platinum heating pieces; a thermal preservation material coats the lower section of the leakage pipe close to the orifice; a groove between the upper parts of the semicircular folding platinum heating pieces is filled with the lower part of the thermal preservation material. According to the device and the disclosed by the invention, the temperature distribution uniformity in an orifice area can be improved, so that the temperature variation gradient of the leakage pipe orifice and the ambient environment is small. Therefore, the device has the characteristic of preventing molten glass from generating crystallization while flowing through the area and is mainly used for melting and molding lanthanide series optical glass.

Description

A kind of leakage expects that mouth prevents the device and method of crystallization

Technical field

The invention belongs to opticglass manufacturing technology field.Be specifically related to a kind of leakage and expect that mouth prevents the device and method of crystallization, the opticglass leakage material being particularly useful for very easily crystallization is shaping.Adopt this device effectively can reduce opticglass and flow through the crystallization produced when Lou expecting the mouth of pipe and the inherent strip flaw of the opticglass caused by crystallization.

Background technology

Opticglass is owing to forming difference, and its high temperature melting characteristic is also different.Very wide to some optical glass having high refractive index crystalline ranges, the easy especially crystallize out when founding, this crystalloid is present in inside glass, causes opticglass interior quality to decline.Particularly lanthanide optical glass, its tendency towards devitrification is strong.In moulding process, near usual leakage material mouth, temperature is too low, be in the crystalline range of this glass, when glass metal flow through Lou expect the mouth of pipe time, can adhere to and Lous expect also to form crystal grain fast around the mouth of pipe, these crystal grain constantly produce and are constantly swept along out by the glass metal of follow-up outflow, enter into glass billot forming mould, shaping glass billot interior quality is declined, forms calculus or strip flaw, cause product quality bad, add production cost and quality risk.

Summary of the invention

Object of the present invention is exactly leak shaping the proposed a kind of homogeneity improving orifice region temperature distribution of material for very easily crystallization opticglass, make leakage the material mouth of pipe and ambient temperature variable gradient little, thus produce the device and method of crystallization when stoping glass metal to flow through this region.

The present invention prevents the technical solution of the device of crystallization from being: a kind ofly leak the device that material mouth prevents crystallization, it is characterized in that: comprise two semi-circulars and fold platinum heating piece, two electrode slices and lagging material; With leakage, each burst in bottom that semi-circular folds platinum heating piece expects that the mouth of pipe is concordant; Two semi-circulars fold platinum heating piece inside lower end and are welded on respectively along upper under the leakage material mouth of pipe of Lou expecting pipe both sides, and two electrode slices are welded on two semi-circulars respectively and fold the outer side edges of platinum heating piece along upper, for accessing low-voltage and high-current source; Lagging material is wrapped in the leakage material pipe hypomere of tube mouth, and lagging material is under-filled folds in the alternate groove in platinum heating piece top at semi-circular.

Semi-circular described in the technical solution of apparatus of the present invention folds in the alternate groove in platinum heating piece top and is provided with temperature thermocouple, folds platinum heating piece to the radiation temperature of leaking the material mouth of pipe for monitoring semi-circular.

The present invention prevents the technical solution of the method for crystallization from being: a kind ofly leak the method that material mouth prevents crystallization, it is characterized in that comprising the following steps:

(1) adopt two semi-circulars to fold platinum heating piece, two electrode slices, lagging material, temperature measuring equipment and low-voltage and high-current sources; Two semi-circulars are folded platinum heating piece inside lower end be welded on respectively Lou expect pipe both sides the leakage material mouth of pipe under along upper, two electrode slices are welded on two semi-circulars respectively and fold the outer side edges of platinum heating piece along upper; Fold in the alternate groove in platinum heating piece top at the leakage material pipe hypomere of tube mouth and semi-circular and wrap up lagging material; Temperature measuring equipment is welded on Lou expects that on pipe, the temperature thermocouple in temperature measuring equipment is arranged on semi-circular and folds in the alternate groove in platinum heating piece top;

(2) first determine the recrystallization temperature upper limit LT of opticglass, this recrystallization temperature upper limit LT is that glass metal keeps 30 minute hands to start the temperature of crystallization at LT temperature; Reset and Lou expect pipe control temperature, setting leaks material pipe temperature range at LT+120 DEG C, and preferred LT+90 DEG C, more preferably LT+60 DEG C, set corresponding semi-circular and fold platinum heating piece temperature range at LT+110 DEG C, preferred LT+80 DEG C, more preferably LT+50 DEG C;

(3), in the moulding process of opticglass, material pipe temperature is leaked in monitoring at any time and semi-circular folds platinum heating piece temperature, control its temperature the (2) article described in scope in, obtain without crystallization and the optical glass strip material without striated surface.

The present invention folds platinum heating piece owing to adopting by two semi-circulars, the leakage material mouth that two electrode slices and lagging material are formed prevents the device of crystallization, wherein, with leakage, each burst in bottom that semi-circular folds platinum heating piece expects that the mouth of pipe is concordant, two semi-circulars fold platinum heating piece inside lower end and are welded on respectively under the leakage material mouth of pipe of Lou expecting pipe both sides along upper, two electrode slices are welded on two semi-circulars respectively and fold the outer side edges of platinum heating piece along upper, lagging material is wrapped in the leakage material pipe hypomere of tube mouth, and lagging material is under-filled folds in the alternate groove in platinum heating piece top at semi-circular, when thus using, first determine the recrystallization temperature upper limit LT of opticglass, this recrystallization temperature upper limit LT is that glass metal keeps 30 minute hands to start the temperature of crystallization at LT temperature, reset and Lou expect pipe control temperature, setting is leaked material pipe temperature and is controlled at LT+120 DEG C, preferred LT+90 DEG C, more preferably LT+60 DEG C, corresponding semi-circular folds platinum heating piece temperature and controls at LT+110 DEG C, preferred LT+80 DEG C, more preferably LT+50 DEG C, in the moulding process of opticglass, material pipe temperature is leaked in monitoring at any time and semi-circular folds platinum heating piece temperature, and carry out appropriate regulation, obviously can promote the temperature of the mouth of pipe, guarantee from leaking the glass fluid column internal and external temperature flowed out in material pipe close, when controlling temperature of glass liquid higher than recrystallization temperature, the crystallization of opticglass can be stoped to occur, obtain without crystallization and the optical glass strip material without striated surface.

Accompanying drawing explanation

Fig. 1 is structural representation of the present invention.

In figure: 1. electrode slice; 2. leak material pipe; 3. lagging material; 4. platinum sheet; 5. leak the material mouth of pipe 6. temperature thermocouple.

Embodiment

As shown in Fig. 1 sectional view.Platinum plate is made the platinum sheet 4 that two semi-annular are folding, platinum sheet 4 inside lower end is welded in respectively Lou expects under the mouth of pipe 5 left and right sides along upper, the platinum sheet 4 of two panels semi-annular multiple folding is except the mouth of pipe 5 place can contact, other positions are not in contact with each other mutually, to ensure not to be short-circuited when using current electrifying heating.Can not fit between platinum plate between two in the folding position of the platinum sheet 4 of single semi-annular multiple folding, with leakage, lower end, each folding position expects that the mouth of pipe 5 is concordant.Leak outside material pipe 2 and in the alternate groove in semi-annular multiple folding platinum sheet 4 top and wrap up resistant to elevated temperatures lagging material 3, platinum sheet 4 bottom of semi-annular multiple folding is placed in air.Electrode slice 1 is welded on the edge of semi-annular multiple folding platinum sheet 4 both sides respectively, access low-voltage and high-current power supply.Leaking on material pipe 2 and be welded with temperature measuring equipment, being welded with temperature thermocouple 6 in the platinum sheet 4 top insulating cotton of semi-annular multiple folding, for monitoring the radiation temperature of platinum sheet 4 line up 5 of semi-annular multiple folding.

Working method: when determining to produce certain trade mark optical glass strip material, the recrystallization temperature upper limit LT(glass metal of this trade mark glass known keeps 30 minute hands to start the temperature of crystallization at such a temperature).When setting leakage material pipe control temperature, for ensureing that glass metal does not produce crystallization in outflow leakage material pipe process, setting is leaked material pipe temperature and is controlled at LT+120 DEG C, preferred LT+90 DEG C, more preferably LT+60 DEG C, the platinum sheet temperature of corresponding semi-annular multiple folding controls at LT+110 DEG C, preferred LT+80 DEG C, more preferably LT+50 DEG C, guarantees that opticglass does not produce crystallization in flow process in platinum pipe and formed glass fluid viscosity is suitable, is beneficial to not produce convection current striped in moulding process.

Embodiment:

According to embodiment, the present invention will be described in more detail, but the invention is not restricted to these examples.

Choose specific refractory power more than 1.83, a kind of opticglass (LT:910 DEG C) of Abbe number 37 carries out volume production experiment as objective for implementation.Under the leakage, identical shaping specification of same glass liquid, by regulating the platinum sheet temperature of leaking material pipe temperature and semi-circular multiple folding, obtain variant production, by judging the product inner quality under various condition.Synthetic determination result is as shown in the table.

Claims (3)

1. leak the device that material mouth prevents crystallization, it is characterized in that: comprise two semi-circulars and fold platinum heating piece, two electrode slices and lagging material; With leakage, each burst in bottom that semi-circular folds platinum heating piece expects that the mouth of pipe is concordant; Two semi-circulars fold platinum heating piece inside lower end and are welded on respectively along upper under the leakage material mouth of pipe of Lou expecting pipe both sides, and two electrode slices are welded on two semi-circulars respectively and fold the outer side edges of platinum heating piece along upper, for accessing low-voltage and high-current source; Lagging material is wrapped in the leakage material pipe hypomere of tube mouth, and lagging material is under-filled folds in the alternate groove in platinum heating piece top at semi-circular.

2. according to claim 1 leakage expects that mouth prevents the device of crystallization, it is characterized in that: described semi-circular folds in the alternate groove in platinum heating piece top and is provided with temperature thermocouple, folding platinum heating piece to the radiation temperature of leaking the material mouth of pipe for monitoring semi-circular.

3. device prevents a method for crystallization according to claim 1, it is characterized in that comprising the following steps:

(1) adopt two semi-circulars to fold platinum heating piece, two electrode slices, lagging material, temperature measuring equipment and low-voltage and high-current sources; Two semi-circulars are folded platinum heating piece inside lower end be welded on respectively Lou expect pipe both sides the leakage material mouth of pipe under along upper, two electrode slices are welded on two semi-circulars respectively and fold the outer side edges of platinum heating piece along upper; Fold in the alternate groove in platinum heating piece top at the leakage material pipe hypomere of tube mouth and semi-circular and wrap up lagging material; Temperature measuring equipment is welded on Lou expects that on pipe, the temperature thermocouple in temperature measuring equipment is arranged on semi-circular and folds in the alternate groove in platinum heating piece top;

(2) first determine the recrystallization temperature upper limit LT of opticglass, this recrystallization temperature upper limit LT is that glass metal keeps 30 minute hands to start the temperature of crystallization at LT temperature; Reset and Lou expect pipe control temperature, setting leaks material pipe temperature range at LT+120 DEG C, and preferred LT+90 DEG C, more preferably LT+60 DEG C, set corresponding semi-circular and fold platinum heating piece temperature range at LT+110 DEG C, preferred LT+80 DEG C, more preferably LT+50 DEG C;

(3), in the moulding process of opticglass, material pipe temperature is leaked in monitoring at any time and semi-circular folds platinum heating piece temperature, control its temperature the (2) article described in scope in, obtain without crystallization and the optical glass strip material without striated surface.