RU2029740C1 - Glass melt feeding device - Google Patents

Abstract

FIELD: glass production. SUBSTANCE: device has hollow member heated by electric unit and enclosed in cylindrical shell, current supplying members, metering unit formed as funnel and conical shunting casing, whose larger ends are connected with hollow member and smaller ends are connected to lower current supplying unit. EFFECT: increased efficiency and simplified construction. 1 dwg

Description

 The invention relates to devices for supplying molten glass from a feeder of a glass melting furnace to die feeders when forming fiberglass in a one-step method or to other glass-forming units, for example, for producing glass beads, and can be used in glass and fiberglass manufacturing enterprises.

 Known jet feeder for supplying molten glass in the production of fiberglass in a one-stage method, made in the form of two electrically heated tubes with current leads inserted one into the other and connected in the upper part, the inner tube made of two sections with separate adjustment of the current load in them [1].

 However, this device has a significant drawback: it is characterized by a short service life due to the burning out of the lower section of the inner tube at the junction with the upper section, which is also the place of welding of the current lead, through which the upper and lower sections of the inner tube are electrically powered, and therefore, the total load current, leading to overheating of the place of welding of the current lead.

 Known inkjet feeder for supplying molten glass, comprising a hollow element in the form of a truncated body with a current supply in the lower part, the feeder contains an additional hollow element in the form of a truncated cone, mounted inside the main hollow element coaxially with the smaller base upward. The feeder also contains a ring with a current lead; the ring and the additional hollow element are rigidly interconnected; the ring is mounted with a gap to the main element. This design allows you to increase the life of the feeder by reducing the temperature of the walls of the hollow elements of the feeder, since the melt is heated due to its resistance, which is several times higher than the resistance to electric current of the material of the feeder [2].

 However, this design does not provide heating of the melt in the lower part of the jet feeder (at the outlet of it) during the start-up period, when the main load current flows through the melt in the feeder, which leads to the burning out of the upper current supply located in this melt.

 Closest to the invention is an inkjet platinum-rhodium feeder for supplying molten glass and controlling flow rate due to the vertical movement of the platinum-rhodium plunger installed above the hollow element of the jet feeder [3].

However, this device has a number of significant disadvantages:
1. Does not provide a uniform flow of the melt using the lower refractory glasses with diathermic, with an upper limit of crystallization of more than 1350 ^{° C,} a reduced viscosity of less than 1,5˙ February ¹⁰ Pa s, the appropriate temperature for ^about 20-40 C above the upper limit of the crystallization temperature , since in the lower part of the jet feeder there is a periodic cooling of the glass melt.

 2. It has a low service life due to the burning of the lower part of the jet feeder if it is necessary to increase its temperature in case of a decrease in the melt temperature in the feeder.

 3. When using refractory glass crystals prone to crystallization with low heat transparency and various rheological and thermophysical properties, it is impossible to calculate the technological parameters of the power supply device, since its design does not allow the application of known physical laws, in particular, the Poiseuille formula for calculating the flow rate (flow rate) ) of the melt, its viscosity, etc., which is a prerequisite in the precision process of feeding the melt into a die feeder for forming thin refractory vkih fibers and glass beads.

 The aim of the invention is to provide a uniform supply to the forming devices of refractory, prone to crystallization of glass melts with low heat transparency, with the necessary and stable flow rate, as well as increasing the life of the supply device.

 This is achieved by the fact that the melt supply device, including an electrically heated hollow element enclosed in a cylindrical casing, and current leads, is equipped with a metering element made in the form of a funnel, and a cone-shaped shunt casing, large bases of which are connected to the hollow element, and smaller ones with lower current lead. The ratio of the channel length of the cylindrical part of the metering element to its diameter is 3-5, and the ratio of the height of the metering element to the height of its conical part is 1.9-5.1.

 The drawing schematically shows a power device.

 The feeding device for supplying the molten glass includes an electrically heated hollow element 1, made in the form of a truncated cone, facing a smaller base downward and enclosed in a cylindrical casing 2.

 The hollow element 1 is provided in the lower base with a metering element 3, made in the form of a funnel, consisting of a conical and cylindrical parts, enclosed in a conical casing-shunt 4, at the same time acting as a heat shield. The cylindrical casing 2 of the hollow element 1 is provided with an upper annular current supply 5, and the metering element 3 and the conical casing-shunt are equipped with a lower current supply 6.

 The supply device is electrically powered through current leads 5 and 6 from the transformer 7. All elements of the supply device are made of platinum-based alloys, for example, platinum-rhodium-ruthenium.

 The device operates as follows.

 Through the hollow element 1, the glass melt from the feeder (not shown) enters the preheated feeder, and passing through the metering element 4 of the proposed design, it is brought to the working viscosity, which ensures uniform flow of the melt to the forming devices with the required flow rate.

= 3-5, а отношение высоты дозирующего элемента Н к высоте его конусной части h - в пределах

= 1,9-5,1.To ensure the necessary stable flow rate of the melt, the ratio of the channel length of the cylindrical part of the metering element l to its diameter d is within

= 3-5, and the ratio of the height of the metering element H to the height of its conical part h is within

= 1.9-5.1.

Performing the above requirements allows to 60-80 ^{° C} to lower the temperature on the elements of the supply device with respect to the dispensing element, which increases the life of the power supply unit by 30-35%.

< 3 и

< 1,9 происходит перегрев дозирующего элемента из-за уменьшения электрического сопротивления и увеличения силы тока, проходящего через дозирующий элемент, что приводит к сокращению срока эксплуатации питающего устройства.In case of non-compliance with these requirements, namely, with constantly consumed power, N = const, d = const and relations

<3 and

<1.9, the metering element overheats due to a decrease in electrical resistance and an increase in the current flowing through the metering element, which leads to a reduction in the life of the power supply device.

> 5 и

> 5,1 происходит понижение температуры дозирующего элемента из-за возрастания его электрического сопротивления при одновременном повышении температуры конусообразного кожуха-шунта в связи с перераспределением токовых нагрузок между дозирующим элементом и конусообразным кожухом-шунтом, что приводит к увеличению теплопотерь во внешнюю среду, нарушению обеспечения необходимого стабильного дебита расплава, а также уменьшает срок эксплуатации питающего и стеклоформующих устройств.In the case of elements with ratios

> 5 and

> 5.1 there is a decrease in the temperature of the dosing element due to an increase in its electrical resistance while increasing the temperature of the cone-shaped shunt-casing due to the redistribution of current loads between the dosing element and the cone-shaped casing-shunt, which leads to an increase in heat loss to the environment, violation of the provision the necessary stable flow rate of the melt, and also reduces the life of the feeding and glass forming devices.

The technical and economic effect of the use of the invention is expressed in the following:
a) increasing the life of the supply device to 30-35% by reducing the temperature of its elements at 60-80 ^{° C;}
b) an increase in the life of the spinneret feeder by 1.5-2 times due to the supply of a melt into it with the parameters necessary for generation, such as the temperature of the melt, its flow rate and viscosity, which eliminates the need to prepare the melt in the spinneret feeder;
c) saving of expensive platinum-based alloys due to the rejection of plungers used for dosing.

Claims (1)

 GLASS MELT SUPPLY DEVICE, including an electrically heated hollow element enclosed in a cylindrical casing and current leads, characterized in that it is equipped with a metering element made in the form of a funnel and a cone-shaped shunt casing, large bases of which are connected to the hollow element, and smaller - with a lower current supply, and the ratio of the channel length of the cylindrical part of the metering element to its diameter is 3 - 5, and the ratio of the height of the metering element to the height of its conical part is 1.9 - 5.1.

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