Mineral extruder for ultra-flexible mineral fire-resistant insulated cables

Abstract

The mineral extruder for ultra-flexible mineral fireproof insulated cable has a housing with a rotatably connected twin-screw rotor. The spiral portion of the twin-screw rotor separates the housing's inner chamber into a front chamber and a rear chamber. A feed port is provided at the top of the front chamber, which is located in a feed box. A discharge port is provided at the tail of the rear chamber, which is provided with a discharge valve. A pipe is provided at the bottom of the front chamber, and a pipe valve is provided on the pipe. By providing a pipe and a pipe valve at the bottom of the front chamber of the twin-screw rotor, a liquid medium that isolates gas is introduced before the material is fed. Then, through the combination of the liquid medium feeding, the rotation of the rotor, and the discharge valve, the gas inside the housing is completely exhausted, so that there is no gas in the internal space of the material before extrusion, which is equivalent to a vacuum environment, but does not have the disadvantages of a vacuum negative pressure environment. A tighter mineral coating layer can be extruded, with no pores inside, and better heat insulation and gas isolation effects.

Description

Technical Field

[0001] The invention relates to the technical field of cable production equipment, and in particular to a mineral extruder for ultra-flexible mineral fireproof insulated cables. Background Art

[0002] Using mineral wrapping to isolate cables from external air and minimize heat transfer to the core is a common method for fire-resistant insulated cables. In high-level engineering projects, cable fire protection requirements are very strict. Class B1 cables require that the duration of dripping particles within the cable after burning for 20 minutes does not exceed 10 seconds. This requires the protective layer to have very high levels of thermal insulation and gas barrier properties. Existing cable mineral wrapping is applied using an extruder. When the extruder is operating, it easily compresses gas into the mineral material, forming cavities, which reduces the thermal and insulating properties of the mineral wrap. The extruder's extrusion structure makes it difficult to form a vacuum space between the feed and discharge chambers. Since the front and rear chambers are nearly isolated by the extrusion mechanism, it is even more difficult to use a vacuum pump to create a vacuum. Furthermore, since there is extrusion residue in the extrusion mechanism chamber, vacuuming the residue will not be drawn into the pump body, making vacuuming difficult to achieve. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a mineral extruder for ultra-flexible mineral fire-proof insulated cables, which can create a vacuum environment in the mineral extruder through a simple device structure, that is, exhaust the air inside the extruder, so that the mineral wrapping layer on the cable after extrusion has better heat insulation and gas isolation effects.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] A mineral extruder for ultra-flexible mineral fire-proof insulated cables includes a shell, in which a rotatably connected twin-screw rotor is provided. The spiral portion of the twin-screw rotor is wrapped by the shell wall but with a gap. The spiral portion of the twin-screw rotor separates the inner chamber of the shell into a front chamber and a rear chamber. A feed port is provided at the top of the front chamber, and the feed port is located in a feed box. A discharge port is provided at the tail of the rear chamber, and a feed valve and a discharge valve are provided at the feed port and the discharge port respectively. A pipe is provided at the bottom of the front chamber, and a pipe valve is provided on the pipe.

[0006] One end of the twin-screw rotor extends out of the housing and is driven by a driving motor, and the other end is rotatably connected to the inside of the housing. Both ends of the twin-screw rotor are sealed with the housing.

[0007] The above-mentioned pipes and valves are used to introduce a gas-isolating liquid medium into the shell before the material is extruded, and to discharge the gas in the shell in conjunction with the discharge valve and the rotation of the twin-screw rotor.

[0008] A first liquid level sensor is provided on the top of the front cavity.

[0009] A second liquid level sensor is provided on the side wall of the feed inlet.

[0010] The feed inlet is provided with a feed valve.

[0011] The above-mentioned feed valve and discharge valve are telescopic valves.

[0012] The above-mentioned feed valve and discharge valve structure is as follows: it includes an electromagnetic coil fixedly connected to the outer wall of the shell, the upper end of the valve stem passes through the electromagnetic coil, the middle section of the valve stem is provided with a limit plate, a spring is provided between the limit plate and the inner wall of the shell, and a door body is provided at the end of the valve stem.

[0013] The feed valve and the discharge valve are tilted in opposite directions of feed and discharge respectively.

[0014] The present invention provides a mineral extruder for ultra-flexible mineral fire-proof insulated cables. The extruder arranges a pipe and a pipe valve at the bottom of the front cavity of the twin-screw rotor to allow a gas-isolating liquid medium to be introduced before the material is fed. The gas inside the shell is then completely discharged through the feeding of the liquid medium, the rotation of the rotor, and the cooperation of the discharge valve. This ensures that there is no gas in the internal space of the material before extrusion, which is equivalent to a vacuum environment but does not have the disadvantages of a vacuum negative pressure environment. A tighter mineral coating layer can be squeezed out without pores inside, which has better heat insulation and gas isolation effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0016] Figure 1 It is a structural schematic diagram of the mineral extruder of the present invention;

[0017] Figure 2 It is a schematic structural diagram of a preferred mineral extruder;

[0018] Figure 3 It is a side view of a mineral extruder;

[0019] Figure 4 for Figure 2 A partial enlarged schematic diagram.

[0020] Among them: shell 1, twin-screw rotor 2, feed box 3, feed port 4, feed valve 5, first liquid level sensor 6, second liquid level sensor 7, discharge port 8, discharge valve 9, pipeline 10, pipe valve 11, electromagnetic coil 12, valve stem 13, limit plate 14, spring 15, door body 16. DETAILED DESCRIPTION

[0021] The technical solution of the present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0022] like Figure 1-4 As shown in the figure, a mineral extruder for ultra-flexible mineral fire-proof insulated cables includes a shell 1, in which a rotatably connected twin-screw rotor 2 is provided. The spiral portion of the twin-screw rotor 2 is wrapped by the wall of the shell 1 but with a gap. The spiral portion of the twin-screw rotor 2 separates the inner chamber of the shell 1 into a front chamber and a rear chamber. A feed port 4 is provided at the top of the front chamber, and the feed port 4 is located in the feed box 3. A discharge port 8 is provided at the tail of the rear chamber. A feed valve 5 and a discharge valve 9 are provided at the feed port 4 and the discharge port 8 respectively. A pipe 10 is provided at the bottom of the front chamber, and a pipe valve 11 is provided on the pipe 10.

[0023] The pipe 10 is used to input a liquid medium that isolates air into the shell 1. The specific gravity of the liquid medium is smaller than that of the mineral body. Before the mineral extrusion operation is performed, the pipe 10 and the discharge valve 9 are first used to cooperate to fill the shell 1 with the liquid medium, so that most of the air is discharged from the feed port 4. Then, while the liquid medium continues to be input into the pipe 10, the twin-screw rotor 2 rotates to discharge the air in the discharge port 8, so that there is no air in the shell 1. The discharge valve 9 is closed, the twin-screw rotor 2 stops rotating, and then the mineral raw material is put into the feed port 4. Since its specific gravity is greater than that of the liquid medium, the mineral raw material will fill the front cavity. At this time, the twin-screw rotor 2 starts the extrusion operation and opens the discharge valve 9. At this time, when the mineral raw material reaches the discharge port 8, it is a mineral extrusion material that is completely free of gas, which is equivalent to production in a vacuum environment. Using a mold to wrap the extruded material around the cable can achieve the existence of no pores in the mineral wrapping layer, greatly increasing the heat insulation and gas isolation effect of the mineral layer.

[0024] One end of the twin-screw rotor 2 extends out of the housing 1 and is driven by the driving motor, and the other end is rotatably connected to the inside of the housing 1 . Both ends of the twin-screw rotor 2 are sealed with the housing 1 .

[0025] The above-mentioned pipeline 10 and pipe valve 11 are used to introduce a gas-isolating liquid medium into the shell 1 before the material is extruded, and to discharge the gas in the shell 1 in conjunction with the discharge valve 9 and the rotation of the twin-screw rotor 2.

[0026] The liquid medium for isolating gas may be a sodium silicate solution, which can simultaneously serve as a mineral binder and a liquid for isolating air.

[0027] Before the extrusion operation, the pipe 10 and the pipe valve 11 are used to pass the liquid medium into the front cavity. The liquid medium enters the rear cavity through the gap between the twin-screw rotors 2, so that the medium fills the shell 1. At this time, the discharge valve 9 is closed and the gas is discharged from the feed port 4. At this time, there is still a certain amount of gas in the pipe connecting the discharge port 8 and the rear cavity and in the gap between the twin screws due to the isolation of the residual material in the gap. While the pipe 10 continues to pass the liquid medium, the discharge valve 9 is opened and the twin-screw rotor 2 is started to discharge the liquid medium in the front cavity toward the rear cavity, so that the residual gas is discharged toward the discharge port 8 due to the extrusion of the liquid. Then the discharge valve 9 is closed and the rotation of the twin-screw rotor 2 is stopped. At this point, the gas is completely discharged from the shell 1 and the material extrusion operation can be carried out.

[0028] A first liquid level sensor 6 is provided on the top of the front cavity.

[0029] The first liquid level sensor 6 is used to sense whether the interior of the housing 1 is filled with a liquid medium that is isolated from gas.

[0030] A second liquid level sensor 7 is provided on the side wall of the feed port 4 .

[0031] The second liquid level sensor 7 is used to sense the liquid level of the liquid medium in the shell 1. The liquid medium in the shell 1 is used to isolate the feed minerals from the air. Since the specific gravity of the liquid medium is much smaller than that of the minerals, the liquid medium always keeps the minerals isolated from the air on the surface of the feed box 3.

[0032] The feed inlet 4 is provided with a feed valve 5 .

[0033] The above-mentioned feed valve 5 and discharge valve 9 are telescopic valves.

[0034] When feeding and discharging materials, the door of the telescopic valve retracts into the wall, and the impact of the material on the door is smaller.

[0035] The above-mentioned feed valve 5 and discharge valve 9 have the following structures: they include an electromagnetic coil 12 fixedly connected to the outer wall of the shell 1, the upper end of the valve stem 13 passes through the electromagnetic coil 12, the middle section of the valve stem 13 is provided with a limit plate 14, a spring 15 is provided between the limit plate 14 and the inner wall of the shell 1, and a door body 16 is provided at the end of the valve stem 13.

[0036] The feed valve 5 can be used for air intake and exhaust operations, that is, when the twin-screw rotor rotates to drive the liquid medium to be extruded backward, the valve is closed so that the liquid medium in the feed box 3 is not disturbed by the extrusion operation, which is convenient for subsequent material feeding. The non-fluctuating liquid is more conducive to the material sinking to the bottom.

[0037] The feed valve 5 and the discharge valve 9 are tilted in opposite directions of feed and discharge, respectively.

[0038] By tilting the feed valve 5 and the discharge valve 9, the insertion openings of the door panels of the two valves on the side walls are opposite to the direction of material flow, so that the material is not easy to enter during flow, which facilitates the closing of the valves.

Claims

1. Mineral extruder for ultra-flexible mineral fireproof insulated cable, characterized in that, The invention comprises a shell (1), wherein a rotatably connected twin-screw rotor (2) is provided in the shell (1), wherein the spiral portion of the twin-screw rotor (2) is wrapped by the shell (1) wall but with a gap, and the spiral portion of the twin-screw rotor (2) separates the inner chamber of the shell (1) into a front chamber and a rear chamber, wherein a feed port (4) is provided at the top of the front chamber, the feed port (4) is located in a feed box (3), a discharge port (8) is provided at the tail of the rear chamber, a discharge valve (9) is provided at the discharge port (8), a pipe (10) is provided at the bottom of the front chamber, and a pipe valve (11) is provided on the pipe (10); One end of the twin-screw rotor (2) extends out of the housing (1) and is driven by a driving motor, and the other end is rotatably connected to the interior of the housing (1). Both ends of the twin-screw rotor (2) are sealed with the housing (1); The pipe (10) and the pipe valve (11) are used to introduce a gas-isolating liquid medium into the housing (1) before the material is extruded, and to discharge the gas in the housing (1) in conjunction with the discharge valve (9) and the rotation of the twin-screw rotor (2); A first liquid level sensor (6) is provided on the top of the front cavity.

2. The mineral extruder for ultra-flexible mineral fireproof insulated cable according to claim 1, characterized in that: A second liquid level sensor (7) is provided on the side wall of the feed box (3).

3. The mineral extruder for ultra-flexible mineral fireproof insulated cable according to claim 2, characterized in that: The feed port (4) is provided with a feed valve (5).

4. The mineral extruder for ultra-flexible mineral fireproof insulated cable according to claim 3, characterized in that: The feed valve (5) and the discharge valve (9) are telescopic valves.

5. The mineral extruder for ultra-flexible mineral fireproof insulated cable according to claim 4, characterized in that: The structure of the feed valve (5) and the discharge valve (9) is as follows: it includes an electromagnetic coil (12) fixedly connected to the outer wall of the shell (1), the upper end of the valve stem (13) passes through the electromagnetic coil (12), the middle section of the valve stem (13) is provided with a limit plate (14), a spring (15) is provided between the limit plate (14) and the inner wall of the shell (1), and a door body (16) is provided at the end of the valve stem (13).

6. The mineral extruder for ultra-flexible mineral fireproof insulated cable according to claim 5, characterized in that: The feed valve (5) and the discharge valve (9) are inclined in opposite directions of feed and discharge, respectively.

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