Method and device for transferring zinc liquid

Abstract

The present invention relates to a method and device for transferring molten zinc, belonging to the technical field of molten zinc transportation. The method and device utilize vacuum negative pressure to extract molten zinc, and cooperate with a rotating mechanism to dump the molten zinc. This method and device can reduce the time required to open the molten zinc outlet of a cored induction furnace and the need to clear blockages at the outlet, thereby saving labor costs and reducing labor intensity. The molten zinc transfer device can better prevent oxidation of the molten zinc in the chute, reduce slag rate and production costs, and minimize temperature loss, thereby saving energy. By calculating the gap ventilation volume, gas and fluid velocities, an optimal power variation characteristic curve is derived, stabilizing molten zinc extraction and improving vacuum extraction efficiency.

Description

Technical Field

[0001] The invention relates to a method and a device for transferring zinc liquid, belonging to the technical field of zinc liquid transportation. Background Art

[0002] Currently, in domestic zinc alloy production, after molten zinc is melted in a cored induction furnace, it is transported to a coreless induction furnace using a chute. This method presents challenges such as zinc oxidation, high slag rates, safety risks from the high-temperature melt, and high-temperature radiation exposure to employees. Domestic technicians used lead pumps as a reference to manufacture zinc pumps. However, due to the severe corrosion of zinc to metals, the zinc pump impeller had a short service life, was costly, and was impractical.

[0003] Therefore, a method and device for transferring zinc liquid are provided to solve the problem that the transfer of zinc liquid is limited by the length and temperature of the chute, and to better prevent the oxidation and scumming of zinc liquid. Summary of the Invention

[0004] To overcome the problems of the prior art, the present invention utilizes a vacuum negative pressure extraction method and device for zinc liquid transfer, coupled with a rotating mechanism for zinc liquid transfer. This method reduces the time required to open the zinc liquid outlet of a cored induction furnace and the need to clear blockages, thereby saving labor costs and reducing labor intensity. The zinc liquid transfer device also effectively prevents zinc liquid from oxidizing in the chute, lowering slag production and production costs, and minimizing zinc liquid temperature loss, thereby saving energy. By calculating the gap ventilation volume, gas and fluid velocities, an optimal power variation characteristic curve is derived, stabilizing zinc liquid transfer and improving vacuum extraction efficiency.

[0005] In order to overcome the problems existing in the background technology and solve the above problems, the present invention is implemented through the following technical solutions:

[0006] A zinc liquid transfer device includes a shell, a thermal insulation layer, a pouring gate, a feed pipe, an air compressor nozzle, a hanger, and a rotating mechanism. The shell is a cylindrical sealable tank with a thermal insulation layer provided inside the shell. The feed pipe is installed at the upper end of the shell. The pouring gate is provided in the middle of the shell opposite to the feed pipe installation surface. An air compressor nozzle is installed on the top of the shell. The hanger is rotatably installed on both sides of the middle of the shell. A rotating mechanism for rotating liquid transfer is provided on the shell.

[0007] Preferably, the rotating mechanism includes a motor, a rotating gear, a driven gear, and a rotating shaft. The driven gear is fixed to the housing through the rotating shaft, the hanger is fixed to the rotating shaft through a bearing, the motor is mounted on the housing, the rotating gear is mounted on the motor output shaft, the rotating gear is engaged with the driven gear, and by driving the driven gear to rotate, the pouring device can rotate to pour the zinc liquid.

[0008] Preferably, the compressed air nozzle is connected to a vacuum pump through a vacuum pipe.

[0009] Preferably, the thermal insulation layer is made of refractory bricks and thermal insulation cotton.

[0010] Preferably, a gate cover is hinged on the gate, and an electromagnetic suction cup is installed on the gate for adsorbing the gate cover.

[0011] A method for transporting zinc liquid includes the following steps:

[0012] Step 1: Use a metallurgical crane to lift the zinc liquid transfer device to the slag removal port of the cored induction furnace. Step 2: Insert the feed pipe of the zinc liquid transfer device into the zinc liquid, start the vacuum pump to create negative pressure in the zinc liquid transfer device, and pump the zinc liquid from the cored induction furnace into the zinc liquid transfer device.

[0013] Step three: Use a metallurgical crane to lift the zinc liquid transfer device onto the coreless induction furnace, open the zinc pouring gate cover, and electrically control the rotating mechanism to pour the zinc liquid into the coreless induction furnace to complete the zinc liquid transfer.

[0014] Preferably, the vacuum pump exhaust control process in step 2 is as follows:

[0015] Step 2.1, calculate the air flow rate between the gate and the gate cover gap;

[0016] Step 2.2, calculate the gas flow rate of the feed pipe and the gas flow rate of the exhaust pipe;

[0017] Step 2.2: Calculate the optimal power variation characteristic curve and suction time of the vacuum pump based on the expected suction volume and negative pressure of the zinc liquid transfer device.

[0018] Preferably, the process of step 2.1 is to install a pressure gauge at the feed port of the zinc liquid transfer device, install an air flow meter on the air compressor nozzle and then connect it to a vacuum pump, detect the pressure change by the pressure gauge under different pressure differences, and calculate the air flow rate of the gate gap. The calculation formula for the gap air flow rate is:

[0019] Q s =S l P a =S m P a / ρ a (1)

[0020] In the formula, Q s Indicates the air volume that penetrates through the door gap, P a represents the absolute atmospheric pressure, ρ a Indicates the atmospheric pressure corresponding to the density, S l represents the gas volume flow rate, S m Indicates the gas mass flow rate.

[0021] Preferably, the calculation process of step 2.2 is to calculate the gas flow rate of the exhaust pipeline:

[0022] Q0=S p CP / (S p +C) (2)

[0023] Where S p Indicates the vacuum pump's pumping speed, C indicates the pipe flow conductance, and P indicates the vacuum pressure; calculate the feed pipe flow conductance,

[0024] Calculation of zinc liquid flow rate in the feed pipe:

[0025]

[0026] Where, u represents the flow rate of zinc liquid, It represents the average pressure at both ends of the pipeline. P0 represents atmospheric pressure, S is the cross-sectional area of ​​the feed pipe;

[0027] Preferably, the calculation process of the optimal power variation characteristic curve of the vacuum pump is as follows: according to steps 2.1 and 2.2, the exhaust equation of the zinc liquid transport device is:

[0028] V0dP / dt=S m P a / ρ a -S p CP / (S p +C) (4)

[0029] Solving formula (5) yields,

[0030] S pi =(-V0ΔPC i ) / (Δt i C i P i +V0ΔP) (5)

[0031] Where S pi Indicates the corresponding t i Vacuum pump speed, Δt i Indicates 0-t i Time step, ΔP represents Δt i The pressure change value of the zinc liquid transfer device within the time period, V0 represents the volume of the zinc liquid transfer device, C i Indicates t i Time ductal conductance, P i Indicates t i The pressure value of the zinc liquid transfer device;

[0032] From the starting pressure P to the ending pressure P i Divide into n segments, given the initial values ​​P and ΔP, find According to P i Using the characteristic curve S of the vacuum pumppi -P calculates the Reynolds number and the conductance C of the feed pipe i , the corresponding time period Δt is obtained from formula (3) i =t i -t0, t0=0, then let P i =(P+ΔP) / 2, and the liquid extraction time t is obtained by superposition calculation.

[0033] The beneficial effects of the present invention are:

[0034] 1. The zinc liquid transfer method and device of the present invention adopts vacuum negative pressure to extract zinc liquid and cooperates with a rotating mechanism to dump the zinc liquid, which can reduce the opening time of the zinc liquid outlet of the core induction furnace and the work of clearing the blockage of the zinc liquid outlet, save labor costs, and reduce labor intensity. The zinc liquid transfer device can better prevent the zinc liquid from oxidizing in the chute, reduce the slag rate and production costs, and reduce the temperature loss of the zinc liquid, saving energy consumption.

[0035] 2. The present invention calculates the gap ventilation volume, gas and fluid velocity to obtain the optimal power change characteristic curve, thereby stabilizing the zinc liquid extraction and improving the vacuum extraction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a front view of the inverting device of the present invention;

[0037] Figure 2 is a cross-sectional view of the inverting device of the present invention;

[0038] Figure 3 It is a schematic diagram of the rotating mechanism of the present invention.

[0039] The numbers in the figure are: 1-shell, 2-thermal insulation layer, 3-gate, 4-feed pipe, 5-air compressed air nozzle, 6-hanger, 7-rotating mechanism, 701-motor, 702-rotating gear, 703-driven gear, 704-rotating shaft, 8-core induction furnace. DETAILED DESCRIPTION

[0040] In order to make the objectives, technical solutions and beneficial effects of the present invention more clear, preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings to facilitate understanding by technicians.

[0041] like Figure 1-3As shown, a zinc liquid transfer device includes a shell 1, a thermal insulation layer 2, a gate 3, a feed pipe 4, an air compressor nozzle 5, a hanger 6, and a rotating mechanism 7. The shell 1 is a cylindrical sealable tank body cast from high-temperature resistant steel 310S stainless steel. A thermal insulation layer 2 is provided in the shell 1. The thermal insulation layer 2 uses refractory bricks and thermal insulation cotton. The feed pipe 4 is installed at the upper end of the shell 1. The feed pipe 4 is made of zinc liquid corrosion-resistant pipes such as titanium tubes or ceramic-plated steel tubes. The gate 3 is arranged in the middle of the shell 1 and is opposite to the installation surface of the feed pipe 4. A gate cover is hinged on the gate 3, and an electromagnetic suction cup is installed on the gate 3. When the gate cover is closed, the electromagnetic suction cup is energized and fixed, which can seal the zinc liquid transfer device to a certain extent. When it needs to be opened, the power is turned off and then opened manually. An air compressor nozzle 5 is installed on the top of the shell 1. The air compressor nozzle 5 is connected to a vacuum pump through a vacuum pipe. The vacuum pump generates negative pressure to extract the zinc liquid in the core induction furnace 8. The hanger 6 can be rotatably installed on both sides of the middle of the shell 1. The hanger 6 is a door-type structure. The upper end of the hanger 6 is connected to a metallurgical crane to move the zinc liquid transfer device.

[0042] The housing 1 is provided with a rotating mechanism 7 for pouring zinc liquid, and the rotating mechanism 7 includes a motor 701, a rotating gear 702, a driven gear 703, and a rotating shaft 704. The rotating shaft 704 is welded on both sides of the housing 1, and the driven gear 703 is fixed to the front end of the rotating shaft 704. The hanger 6 is fixed on the rotating shaft 704 through a bearing, so that the zinc liquid transfer device is tilted at a certain angle through the bearing. The motor 701 is fixed to the fixed platform by bolts. The motor 701 is a three-phase asynchronous motor. The fixed platform is welded to the housing 1. The rotating gear 702 is installed at the front end of the output shaft of the motor 701. The rotating gear 702 and the driven gear 703 are engaged with each other, and the driven gear 703 is driven to rotate by the motor 701. The control circuit of the motor 701 is a forward and reverse self-locking circuit connection, so that the transfer device can rotate at a certain speed to pour the zinc liquid and return to its original position. A hexagonal mounting hole is provided on the fixed point of the central axis on the right side of the rotating gear 702 for fixedly installing a manual rotating disk.

[0043] A method for transporting zinc liquid includes the following steps:

[0044] Step 1: Use a metallurgical crane to lift the zinc liquid transfer device to the slag removal port of the core induction furnace; Step 2: Slowly lower the zinc liquid transfer device and insert the feed pipe of the zinc liquid transfer device into the zinc liquid. Start the vacuum pump to create negative pressure in the zinc liquid transfer device, and the zinc liquid is pumped from the core induction furnace to the zinc liquid transfer device;

[0045] Step three: After the zinc liquid is extracted, the zinc liquid transfer device is hoisted onto the coreless induction furnace using a metallurgical crane, the zinc pouring gate cover is opened, the motor of the electric control rotation mechanism is started, the transfer device rotates and tilts forward at a certain speed, and the zinc liquid is poured into the coreless induction furnace, completing the zinc liquid transfer.

[0046] During the process of starting the vacuum pump to suck the zinc liquid in step 2, the vacuum pump suction control method is as follows:

[0047] Step 2.1, calculate the air flow rate between the gate and the gate cover gap;

[0048] Step 2.2, calculate the gas flow rate of the feed pipe and the gas flow rate of the exhaust pipe;

[0049] Step 2.2: Calculate the optimal power variation characteristic curve and suction time of the vacuum pump based on the expected suction volume and negative pressure of the zinc liquid transfer device.

[0050] The process of step 2.1 is to install a pressure gauge at the feed port of the zinc liquid transfer device, install an air flow meter on the air compressor nozzle and then connect it to the vacuum pump to measure the extracted gas. The pressure change is detected by the pressure gauge under different pressure differences to calculate the ventilation volume of the gate gap. The ventilation volume of the gap in a unit time period is calculated as follows:

[0051] Q s =S l P a =S m P a / ρ a (1)

[0052] In the formula, Q s Indicates the air volume that penetrates through the door gap, P a represents the absolute atmospheric pressure, ρ a Indicates the atmospheric pressure corresponding to the density, S l represents the gas volume flow rate, S m Indicates the gas mass flow rate.

[0053] The calculation process of step 2.2 is to calculate the gas flow rate of the exhaust pipeline:

[0054] Q0=S p CP / (S p +C) (2)

[0055] Where S p Indicates the vacuum pump's pumping speed, C indicates the pipe flow conductance, and P indicates the vacuum pressure; calculate the feed pipe flow conductance,

[0056] Feed pipe flow calculation: The flow state in the pipeline needs to be determined according to the Reynolds number Re. When Re < 2000, it is laminar flow, otherwise it is turbulent flow. The expression of Re is 14:

[0057]

[0058] Where, is the average density of the liquid in the pipe; D is the pipe diameter, u is the average flow velocity of the liquid in the pipe, and μ is the dynamic viscosity of the liquid.

[0059] Under the ideal isothermal condition, the zinc melt satisfies

[0060]

[0061] Assume that the average flow rate u of the liquid in the pipe is determined by the pumping speed S p Approximately, according to formula (6) (7) we get

[0062]

[0063] For a uniform circular cross-section pipe, the pressure difference at both ends can be expressed by Fanning's formula

[0064]

[0065] Where L is the total length of the pipeline, γ is the resistance coefficient related to the flow state, and

[0066]

[0067] From formulas (6)-(10), we can get

[0068]

[0069] Where u represents the gas flow rate, Indicates the average pressure of pipeline gas, P0 represents atmospheric pressure, S is the cross-sectional area of ​​the feed pipe;

[0070] The calculation process of the optimal power change characteristic curve of the vacuum pump is as follows: According to steps 2.1 and 2.2, the exhaust equation of the zinc liquid transport device is:

[0071] V0dP / dt=S m P a / ρ a -S p CP / (S p +C) (4)

[0072] Solving formula (5) yields,

[0073] S pi =(-V0ΔPC i ) / (Δt i C i P i +V0ΔP) (5)

[0074] Where S pi Indicates the corresponding t i Vacuum pump speed, Δt i Indicates 0-t i Time step, ΔP represents Δt iThe pressure change value of the zinc liquid transfer device within the time period, V0 represents the volume of the zinc liquid transfer device, C i Indicates t i Time ductal conductance, P i Indicates t i The pressure value of the zinc liquid transfer device;

[0075] From the starting pressure P to the ending pressure P i Divide into n segments, given the initial values ​​P and ΔP, find According to P i Using the characteristic curve S of the vacuum pump pi -P calculates the Reynolds number and the conductance C of the feed pipe i , the corresponding time period Δt is obtained from formula (3) i =t i -t0, t0=0, then let P i =(P+ΔP) / 2, and the liquid extraction time t is obtained by superposition calculation.

[0076] According to S pi Indicates the corresponding t i The vacuum pump is controlled according to the vacuum pump pumping speed and optimal power change characteristic curve to stabilize the zinc liquid extraction and improve the vacuum extraction efficiency.

[0077] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A method for transporting zinc liquid, characterized in that: The following steps are involved: Step 1: Use a metallurgical crane to lift the zinc liquid transfer device to the slag outlet of the cored induction furnace; the zinc liquid transfer device includes a shell, a thermal insulation layer, a pouring gate, a feed pipe, an air-compressed tuyere, a hanger, and a rotating mechanism. The shell is provided with a thermal insulation layer, the feed pipe is installed at the upper end of the shell, the pouring gate is provided in the middle of the shell opposite to the feed pipe installation surface, the air-compressed tuyere is installed on the top of the shell, the hanger is rotatably installed on both sides of the middle of the shell, and the shell is provided with a rotating mechanism for rotating liquid transfer; Step 2: inserting the feed pipe of the zinc liquid transfer device into the zinc liquid, starting the vacuum pump to form a negative pressure in the zinc liquid transfer device, and pumping the zinc liquid from the core induction furnace into the zinc liquid transfer device, wherein the vacuum pump is connected to an air compressor nozzle; Step 2.1, calculate the air flow rate between the gate and the gate cover gap; Step 2.2, calculate the gas flow rate of the feed pipe and the gas flow rate of the exhaust pipe; Step 2.2, calculating the optimal power variation characteristic curve and suction time of the vacuum pump based on the expected suction volume and expected negative pressure of the zinc liquid transfer device; Step three, use a metallurgical crane to lift the zinc liquid transfer device onto the coreless induction furnace, open the zinc pouring gate cover, and electrically control the rotating mechanism to pour the zinc liquid into the coreless induction furnace to complete the zinc liquid transfer; wherein, the rotating mechanism includes a motor, a rotating gear, a driven gear, and a rotating shaft, the driven gear is fixed to the housing through the rotating shaft, the hanger is fixed to the rotating shaft through a bearing, the motor is installed on the housing, the rotating gear is installed on the motor output shaft, the rotating gear is engaged with the driven gear, and drives the driven gear to rotate.

2. A zinc liquid transport method according to claim 1, characterized in that: The process of step 2.1 is to install a pressure gauge at the feed port of the zinc liquid transfer device, install an air flow meter on the air compressor nozzle and then connect it to the vacuum pump. The pressure change is detected by the pressure gauge under different pressure differences, and the air flow rate of the gate gap is calculated. The calculation formula of the gap air flow rate is: （1） In the formula, Indicates the air volume that penetrates through the door gap. represents the absolute atmospheric pressure, Indicates the atmospheric pressure corresponding to the density, represents the gas volume flow rate, Indicates the gas mass flow rate.

3. A zinc liquid transporting method according to claim 1, characterized in that: The calculation process of step 2.2 is to calculate the gas flow rate of the exhaust pipeline: （2） Where, Indicates the vacuum pumping speed, represents the pipe conductance, Indicates vacuum pressure; calculate feed pipe conduction flow, Calculation of zinc liquid flow rate in the feed pipe: （3） Where, Indicates the flow rate of zinc liquid, It represents the average pressure at both ends of the pipeline. , represents atmospheric pressure, S is the cross-sectional area of ​​the feed pipe; 4. A zinc liquid transporting method according to claim 1, characterized in that: The calculation process of the optimal power change characteristic curve of the vacuum pump is as follows: According to steps 2.1 and 2.2, the exhaust equation of the zinc liquid transport device is: （4） Solving formula (5) yields, （5） Where, Indicates correspondence Vacuum pump speed, Indicates 0- Time period step, express The pressure change value of the zinc liquid transfer device within the time period, Indicates the volume of the zinc liquid transfer device, express When the catheter flow conductance, express The pressure value of the zinc liquid transfer device; From the starting pressure To the end pressure Divide into n segments, give the initial value and , to obtain ,according to Using the characteristic curve of the vacuum pump - Calculate the Reynolds number and feed pipe conductance , the corresponding time period is obtained from formula (3) , , and then , and perform superposition calculation to obtain the liquid extraction time t.

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