RU2745785C1 - Method for forming a glass pipe nozzle and a device for its implementation - Google Patents

Abstract

FIELD: glass materials production.

SUBSTANCE: group of inventions relates to the production of glassy materials, in particular to the method of bell-shaped formation of a glass pipe, and can be used in the manufacture of equipment for the chemical, biological, pharmaceutical industries, in particular, to the technology of manufacturing capacitor devices, filters, sedimentation tanks and distillates. In the method of forming a tube socket, including placing a mandrel in a glass tube blank, heating the blank, according to the invention, the glass tube is rigidly fixed in a vertical position, heating is carried out in a two-zone furnace with separate temperature control for each zone, while the furnace with a mandrel placed in it is made with the possibility of vertical movement relative to the glass tube as the glass softens, forming the required tube geometry, while the working part of the cone-shaped mandrel is placed in the upper heating zone of the furnace designed to heat the point of contact of the glass tube with the mandrel, the second lower heating zone is configured to anneal the finished bell glass tube, nitrogen is supplied to the inside of the furnace above the upper heating zone, and the difference between the diameters of the workpiece and the mandrel made of graphite is determined from the ratio: (D1-D) = (0.1 ÷ 0.25) h, where D is the inner diameter of the workpiece; D1 - diameter of the graphite mandrel, corresponding to the diameter of the socket on the finished product; h is the height from the point where the workpiece touches the mandrel to the beginning of the diameter D1.

EFFECT: improved quality of the product by eliminating the likelihood of pipe sagging, increased service life, as well as simplified and reduced the cost of a device for making a bell of a glass pipe.

6 cl, 8 dwg

Description

The group of inventions relates to the production of glassy materials, in particular to the method of bell-shaped formation of a glass tube and can be used in the manufacture of equipment for the chemical, biological, pharmaceutical industries, in particular, to the technology of manufacturing capacitor devices, filters, sedimentation tanks and distillates.

The known method and device for forming a glass tube from glass blanks (see the application of the Russian Federation No. 2018142878 according to the class IPC С03B23 / 07, publ. 09.07.2020). The method includes heating a glass ingot to a temperature above the glass transition temperature of the glass ingot, the glass ingot having an outer surface defining the outer diameter of the glass ingot and a channel passing through the glass ingot, the channel defining the inner diameter of the glass ingot; pulling the glass tube out of the glass ingot vertically downward, whereby the outer diameter of the glass ingot is reduced to the outer diameter of the glass tube; and passing a stream of compressed gas through the channel of the glass ingot while pulling the glass tube vertically downward, thereby increasing the inner diameter of the glass ingot to the inner diameter of the glass tube.

The device comprises a furnace extending in a substantially vertical direction; a source of compressed gas in fluid communication with a channel of a glass ingot located inside the furnace by means of a supply conduit, the source of compressed gas providing a flow of compressed gas into the channel; at least one pair of pulling rollers located downstream of the furnace and intended to come into contact with a glass tube drawn from the glass ingot; inner diameter caliber; outer diameter caliber; and an electronic control unit connected with the possibility of exchanging information with the caliber of the inner diameter, the caliber of the outer diameter, a source of compressed gas, and with at least one pair of pulling rollers, while the electronic control unit contains a processor and non-volatile memory for storing computer readable and executable commands that, when executed by the processor: adjust at least the speed or torque of at least one pair of pull rollers; and adjusting the flow rate of the compressed gas supplied from the compressed gas source.

However, the method and device do not solve the problem of bell-shaped formation of a glass tube.

There is a known method of socket formation of the end of a tube made of thermoplastic material and a device for its implementation, described in patent RU2423233, IPC B29C57 / 02, publ. 10.07.2011). The method includes the steps of inserting the first mandrel into the end to widen the end without forming a bell. The first mandrel is then pulled out from the flared end. The shape of the flared end is then stabilized and a second mandrel is inserted into the flared end to form the flared flared end. The heater is located inside the mandrel. With this method, the tube is fixed horizontally in the clamping device. Due to the combination of the mechanical expanding action of the mandrel with the thermal effect, the socket section is formed.

The machine for socket forming the ends of the tubes is connected to the extruder via a transfer station and comprises a first feeding device of a known type for feeding each tube in a horizontal direction parallel to the longitudinal axis of the tube from the transfer station to the loading station. The tube is fed by the device through a heating station expanding and a second heating station forming a bell and a cooling station in series. The station has a heating device with a carriage and an oven, which has a cylindrical shape and is installed above the carriage. The station also has a forming and cooling device.

However, this method and device are intended for the socket formation of only thermoplastic (polyolefin) materials. When machining in a horizontal position, the pipe may sag. To achieve high temperatures, it is ineffective to locate the heater inside the mandrel.

The closest in technical essence to the proposed solution are a method and device for producing a tube from high-temperature glass (quartz) by zone heating and softening the tube with a movable heating zone in a horizontal position (see patent for invention US9957185, IPC С03B23 / 08, dated 01.05.2018 ). The pipe is located horizontally and constantly rotates around its axis. The quartz tube is continuously formed by the radial expansion of the softened area under the action of centrifugal force and / or internal overpressure. Excess pressure is supplied to the inside of the pipe. The outer wall of the tube is supported by a graphite mandrel as support. The method and device make it possible to expand the workpiece in one or a small number of stages of shaping into a glass tube with a large outer diameter and high dimensional accuracy. Differential wall thickness adjustment is ensured by supplying coolant to the area with a minimum wall thickness.

However, with this method of processing in a horizontal position, it is necessary to accurately control the viscosity of the glass in the heating zone due to the high probability of pipe sagging. In addition, the use of open flame heating of the burners will not allow accurate maintenance and regulation of the temperature in the heating zone. The source does not contain information about the protection in the area of the open flame of the graphite mandrel against burnout and wear.

The technical problem of the claimed inventions is the bell-shaped shaping of a glass pipe, in particular with the possibility of manufacturing a bell with both one and several transitions.

The technical result of the group of inventions is to improve the quality of the product by eliminating the likelihood of pipe sagging, increasing the service life, as well as simplifying and reducing the cost of a device for manufacturing a bell of a glass pipe.

The technical problem and the technical result are achieved by the fact that in the method of forming a tube socket, including placing a mandrel in a glass tube blank, heating the blank according to the invention, the glass tube is rigidly fixed in a vertical position, heating is carried out in a two-zone furnace with separate temperature control for each zone, in this case, the furnace with the mandrel placed in it is made with the possibility of vertical movement relative to the glass tube as the glass softens, forming the required tube geometry, while the working part of the cone-shaped mandrel is placed in the upper heating zone of the furnace designed to heat the place of contact of the glass tube with the mandrel, the second lower heating zone is made with the possibility of annealing the finished bell of the glass tube, nitrogen is supplied to the inside of the furnace above the upper heating zone, and the difference between the diameters of the workpiece and the mandrel made of graphite is determined from the ratio:

(D1-D) = (0.1 ÷ 0.25) h,

where D is the inner diameter of the workpiece; D1 - diameter of the graphite mandrel, corresponding to the diameter of the socket on the finished product; h is the height from the point where the workpiece touches the mandrel to the beginning of the diameter D1.

Vertical movement of the furnace carry out under the action of a counterweight.

The mandrel may contain an additional section with a diameter D2 to form an additional socket, while the difference between the diameters of the workpiece and the additional section of the mandrel is determined from the ratio:

(D2-D1) / h1 = 0.1 ÷ 0.25,

where D1 is the diameter of the mandrel and the diameter of the first socket on the finished product;

D2 - diameter of the mandrel and the diameter of the additional socket on the finished product;

h1 is the distance between sections D1 and D2.

The device for implementing the method comprises a frame on which a two-zone furnace capable of vertical movement with separate temperature control in each zone is placed, a mandrel located in the upper zone of the furnace, having a cone-shaped working part, hingedly fixed on the frame, a cassette for a glass tube blank, made with the possibility of fixing in a vertical position opposite the mandrel, the tube for supplying nitrogen to the inner cavity of the furnace above the upper heating zone, while the furnace is equipped with a plug installed from below to prevent air circulation, while the diameter of the working part of the mandrel corresponds to the diameter of the bell.

Bake contains counterweight for vertical movement of the furnace regarding the cassette. The mandrel may contain an additional section to form an additional bell

The group of inventions is illustrated by drawings, which depict:

- in fig. 1 is a general view of the installation for the formation of a bell of a glass pipe with a lowered and raised cassette with a pipe;

- in fig. 2 - furnace for forming the bell of a glass pipe;

- in fig. 3 - product with one socket;

- in fig. 4 - mandrel for manufacturing a product with one socket;

- in fig. 5 - product with two sockets;

- in fig. 6 - mandrel for manufacturing a product with two sockets.

Positions in the drawings indicate:

1.main frame;

2. cassette for billet pipe;

3. oven;

4. counterweight;

5. billet pipe;

6. upper heating zone;

7. lower heating zone;

8. graphite mandrel;

9.nitrogen supply tube;

10. direction of nitrogen supply;

11. plug;

12. tapered part of the mandrel;

13. the second tapered part of the mandrel.

A cassette 2 is installed on the main frame 1. A blank tube is loaded into the cassette 2. The cassette 2 with the pipe 5 rises to a vertical position and is fixed in it. A furnace 3 with a counterweight 4 weighing from 6 to 10 kg is installed on the main frame. Resistance furnace 3 cylindrical type with two independent heating zones (upper zone 6 and lower zone 7). Heating zone 6 is the main one, in it the workpiece 5 is heated to the glass softening temperature. Heating zone 7 is necessary for faster heating of the furnace 3, maintaining the set temperature and annealing the product. Dimensions L2 and L4 determine the width of the heating zones, dimension L1 specifies the position of zone 6 relative to the top of the furnace, L3 - the distance between heating zones 6 and 7. Length L3 excludes the mutual influence of the heating zones. The L1 dimension is set to 0.9 L2 for smooth heating of the workpiece and to prevent the furnace from cooling down. L2 depends on the number and length of the flare transitions. L4 is assumed to be equal to half the length of the socket. The diameter of the inner cavity of the furnace is taken to be equal to the diameter of the workpiece.

The graphite mandrel 8 of a given shape is rigidly fixed in the furnace 3. The graphite mandrel 8 has a tapered part 12 with a diameter of the working part D1. The tapered parts 12 and 13 of the graphite mandrel 8 are located in the hot part of the heating zone 6.

Above the upper heating zone 6, a nitrogen supply tube 9 is introduced into the inner cavity of the furnace, indicating the direction of supply 10. The nitrogen supply tube 9 is located around the circumference of the internal cavity of the furnace. Through the holes along the entire length of the tube 9, nitrogen is supplied to the furnace cavity on the tapered part 12 and the working part D1 of the graphite mandrel. A plug 11 installed at the bottom of the oven prevents air circulation.

To obtain the article of FIG. 3, a graphite mandrel of the shape of FIG. 4 is provided. To obtain the article of FIG. 5, a graphite mandrel with the shape of FIG. 6 is proposed. The tapered part 12 of the graphite mandrel 8 is determined from the ratio:

(D1-D) / h = 0.1 ÷ 0.25, where D is the inner diameter of the workpiece, D1 is the diameter of the graphite mandrel,

h is the height from the point where the workpiece touches the mandrel to the beginning of the diameter D1. A deviation from this ratio leads to the destruction of the workpiece at the beginning of shaping, or an overestimation of the size of the finished product relative to D1. If the pipe contains an additional socket section, then the tapered part 13 of the graphite mandrel 8 is determined from the ratio: (D2-D1) / h1 = 0.1 ÷ 0.25, where D1 is the socket diameter on the finished product, D2 is the diameter of the graphite mandrel and the diameter additional socket on the finished product, h1 - Distance between sections D1 and D2.

The method is implemented as follows. The pipe 5 (workpiece) is rigidly fixed in the cassette 2, installed in a vertical position relative to the graphite mandrel 8. Nitrogen is supplied to the furnace cavity 3 through the nitrogen supply pipe 9. Nitrogen is supplied to the working part of the mandrel at the lowest possible flow rate, which protects the graphite mandrel from burnout and loosening.

The upper zone of the furnace is heated to the glass softening temperature, and the lower zone to the glass annealing temperature. The furnace 3 is brought in until the graphite mandrel 8 touches the billet pipe 5. Under the influence of the temperature of the upper heating zone 6, the glass billet 5 softens. When the glass reaches sufficient viscosity, the furnace 3 with the graphite mandrel 8 begins to move upward under the action of the counterweight. A furnace with a graphite mandrel, rising gradually, enters the softened pipe, forming a bell of a given height. Simultaneously with the formation of the bell, annealing occurs in the heating zone 7. After annealing, the furnace 3 is lowered by a pneumatic cylinder (not shown) to its original position.

The method makes it possible to produce a bell-shaped expansion of a glass tube by introducing a graphite mandrel into a workpiece preheated to the glass softening temperature.

An example of a specific implementation. To obtain the funnel of FIG. 7, the furnace of FIG. 2 with the following dimensions: for the outer diameter of the workpiece 40 mm, the diameter of the inner cavity of the furnace is 80 mm, L1 = 49 mm, L2 = 55 mm, L3 = 67 mm, L4 = 100 mm. Nitrogen was fed into the furnace cavity at a flow rate of 0.1 m ³ / hour.

The socket was formed at a temperature of the upper zone of 870 ° C, of the lower zone of 500 ° C (annealing temperature). The counterweight was 8 kg.

A graphite mandrel was used as shown in FIG. 8, with dimensions calculated according to the stated formulas. The coefficient was taken equal to 0.175. Based on the technological features, the diameter of the graphite mandrel should be 0.2 mm less than the inner diameter of the socket of the finished product.

h = (D1-D) / 0.1 ÷ 0.25 = (36.2-35.4) / 0.175 = 4.57 mm,

knowing h, you can calculate the angle α of the tapered part of the mandrel by the formula:

α = 2 * arctan ((D1-D) 2 * h) = 2 * arctan ((36.2-35.4) / 2 * 4.57 = 10˚

h1 = (D2-D1) / 0.1 ÷ 0.25 = (43.4-36.2) / 0.175 = 41.1 mm,

knowing h1, you can calculate the angle of the tapered part of the mandrel by the formula:

α = 2 * arctan ((D2-D1) / 2 * h1) = 2 * arctan ((43.4-36.2) / 2 * 41.1 = 10˚

Thus, the claimed group of inventions allows the formation of a glass pipe with one or more sockets, eliminating the likelihood of the pipe sagging, thereby increasing the quality of the product.

Claims (14)

1. A method of forming a tube socket, including placing a mandrel in a glass tube blank, heating the blank, characterized in that the glass tube is rigidly fixed in a vertical position, heating is carried out in a two-zone furnace with separate temperature control for each zone, while the furnace is located in it the mandrel is made with the possibility of vertical movement relative to the glass tube as the glass softens, forming the required tube geometry, while the working part of the cone-shaped mandrel is placed in the upper heating zone of the furnace designed to heat the point of contact of the glass tube with the mandrel, the second lower heating zone is made with the possibility After annealing the finished socket of the glass tube, nitrogen is supplied to the inside of the furnace above the upper heating zone, and the difference between the diameters of the workpiece and the mandrel made of graphite is determined from the ratio: (D1-D) = (0.1 ÷ 0.25) h, where D is the inner diameter of the workpiece; D1 - diameter of the graphite mandrel, corresponding to the diameter of the socket on the finished product; h is the height from the point where the workpiece touches the mandrel to the beginning of the diameter D1. 2. The method according to claim. 1, characterized in that the vertical movement of the furnace is carried out under the action of a counterweight. 3. The method according to claim 1, characterized in that the mandrel contains an additional section with a diameter D2 for the formation of an additional socket, while the difference between the diameters of the workpiece and the additional section of the mandrel is determined from the ratio: (D2-D1) / h1 = 0.1 ÷ 0.25, where D1 is the diameter of the mandrel and the diameter of the first socket on the finished product; D2 - diameter of the mandrel and the diameter of the additional socket on the finished product; h1 is the distance between sections D1 and D2. 4. A device for implementing the method according to claim 1, characterized in that it contains a frame on which a two-zone furnace capable of vertical movement with separate temperature control in each zone is placed, a mandrel located in the upper zone of the furnace, having a cone-shaped working part, is hinged a cassette mounted on the frame for a glass tube blank, made with the possibility of fixing in a vertical position opposite the mandrel, a tube for supplying nitrogen to the inner cavity of the furnace above the upper heating zone, while the furnace is equipped with a plug installed from below to prevent air circulation, while the diameter of the working part of the mandrel corresponds to socket diameter. 5. The device according to claim. 4, characterized in that the furnace contains a counterweight for vertical movement of the furnace relative to the cassette. 6. The device according to claim. 4, characterized in that the mandrel contains an additional section for the formation of an additional bell.

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