Yellow phosphorus production system and working method thereof

Abstract

The present invention relates to a yellow phosphorus production system and a working method thereof. The yellow phosphorus production system includes: an industrial furnace; a first flue gas conveying pipe provided with a first control valve; a heating device connected to the industrial furnace via the first flue gas conveying pipe; a bag filter connected to the heating device via a second flue gas conveying pipe; a third flue gas conveying pipe provided with a second control valve, one end of which is connected to the bag filter and the other end is connected to a spray device; a circulation pipe, one end of which is connected to the first flue gas conveying pipe and is located between the heating device and the first control valve, and the other end of which is connected to the third flue gas conveying pipe and is located between the bag filter and the second control valve, the circulation pipe being provided with a third control valve and a fourth control valve; and a nitrogen supply pipe connected to the circulation pipe. The yellow phosphorus production system according to the present invention can effectively reduce the possibility of condensation of yellow phosphorus flue gas in the pipeline and reduce the possibility of pipeline blockage.

Description

Technical Field

[0001] The present invention relates to the field of yellow phosphorus production, and in particular to a yellow phosphorus production system and a working method thereof. Background Art

[0002] The electric furnace method for producing yellow phosphorus involves feeding a mixed charge through a feed pipe into an electric furnace. A reduction reaction occurs under the action of electric heat. The phosphorus-containing furnace gases undergo multi-stage condensation and scrubbing to produce crude phosphorus, which is then refined and separated through multiple stages of refinement to yield finished phosphorus. This process generates large amounts of wastewater and sludge, causing serious environmental pollution and high disposal costs. This complex production process results in a complex composition of phosphorus-containing furnace gases, high particulate matter concentrations, and significant fluctuations due to the influence of raw materials and operation. This results in low comprehensive raw material utilization and low yellow phosphorus recovery rates.

[0003] At present, the recovery of sludge phosphorus generally adopts the rotary pot method, that is, the yellow phosphorus tail gas is burned and heated outside the rotary pot, first evaporating about 60-70% of the water in the sludge phosphorus, and then gradually heating to the furnace temperature of 700-800℃ to evaporate the phosphorus, so that the phosphorus content of the residue is reduced to below 1%. The operation cycle of each pot of phosphorus evaporation is generally 6-8 hours.

[0004] Currently, some yellow phosphorus production methods involve pre-purifying the yellow phosphorus furnace gas, which can effectively avoid the formation of sludge phosphorus. However, these yellow phosphorus production methods typically start production directly, which results in relatively low temperatures throughout the production system. Once the yellow phosphorus furnace gas enters the production system pipelines, condensation easily forms, potentially blocking the pipelines and adversely affecting yellow phosphorus production. Summary of the Invention

[0005] Based on the above-mentioned defects in the prior art, the object of the present invention is to provide a yellow phosphorus production system and a working method thereof, which can effectively reduce the possibility of condensation of yellow phosphorus fume in the pipeline and reduce the possibility of pipeline blockage.

[0006] To this end, the present invention provides the following technical solutions.

[0007] The present invention provides a yellow phosphorus production system, which comprises:

[0008] Industrial furnaces for producing yellow phosphorus fume;

[0009] A first flue gas conveying pipe is provided with a first control valve;

[0010] a heating device connected to the industrial furnace via the first flue gas conveying pipe, and at least used to heat the yellow phosphorus flue gas;

[0011] a bag filter connected to the heating device via a second flue gas conveying pipe;

[0012] a third flue gas conveying pipe provided with a second control valve, one end of which is connected to the bag filter and the other end of which is connected to the spraying device;

[0013] a circulation pipe, one end of which is connected to the first flue gas conveying pipe and is located between the heating device and the first control valve, and the other end of which is connected to the third flue gas conveying pipe and is located between the bag filter and the second control valve, the circulation pipe being provided with a third control valve and a fourth control valve; and

[0014] A nitrogen supply pipe is used to input nitrogen for replacement. The nitrogen supply pipe is connected to the circulation pipeline and is located between the third control valve and the fourth control valve.

[0015] In at least one embodiment, the system further includes an air supply pipe connected to the circulation pipe and located between the third control valve and the fourth control valve.

[0016] In at least one embodiment, a circulation fan is provided on the circulation pipeline, and the circulation fan is provided between the third control valve and the fourth control valve.

[0017] In at least one embodiment, a variable frequency fan is provided on the third flue gas conveying duct, and the variable frequency fan is provided between the bag filter and the second control valve;

[0018] The first flue gas conveying pipe is provided with a pressure transmitter, and the pressure transmitter is interlocked with the variable frequency fan for control.

[0019] In at least one embodiment, the first smoke conveying pipe is vertically arranged, and the heating device is vertically inserted into the first smoke conveying pipe from the top of the first smoke conveying pipe.

[0020] In at least one embodiment, an ash discharge device is further included, wherein the ash discharge device includes an ash discharge hopper, and the ash discharge hopper is connected to the lower end of the bag dust collector for receiving the ash in the bag dust collector.

[0021] In at least one embodiment, a dust cleaning device is further included, wherein the dust cleaning device includes an air supply portion, a heating portion, a dust cleaning air pipe and a pulse valve.

[0022] The air supply part contains compressed nitrogen, the heating part is used to heat the compressed nitrogen, the air supply part is connected to the bag filter through the dust cleaning air pipe, and the pulse valve is provided on the dust cleaning air pipe.

[0023] The present invention also provides a working method of the yellow phosphorus production system described in any of the above embodiments, the working method comprising:

[0024] Before officially starting production, the first control valve and the fourth control valve are closed, the second control valve and the third control valve are opened, and nitrogen at room temperature is introduced from the nitrogen supply pipe to the entire pipeline of the yellow phosphorus production system for gas replacement;

[0025] After the replacement is completed, the second control valve is closed, the fourth control valve is opened, and the heating device is started to heat the nitrogen in the entire pipeline to a predetermined temperature.

[0026] In at least one embodiment, a circulation fan is provided on the circulation pipeline. When the heating device heats the nitrogen, the circulation fan operates to circulate the nitrogen in the entire pipeline.

[0027] In at least one embodiment, after stopping production, the first control valve is closed, the third control valve is opened, and nitrogen with a temperature greater than 180° C. is input from the nitrogen supply pipe and the heating device to the entire pipeline of the yellow phosphorus production system for gas replacement; and

[0028] When the equipment is being repaired, air is introduced from the circulation pipeline to replace the nitrogen in the entire pipeline.

[0029] Beneficial effects

[0030] According to the yellow phosphorus production system of the present invention, by providing a circulation pipeline and a nitrogen supply pipe, gas replacement can be performed on the pipelines of the entire production system before the formal yellow phosphorus production begins. The nitrogen in the pipeline can be circulated and heated to a predetermined temperature using a heating device. In this way, after the formal start of production, the possibility of yellow phosphorus fume entering the pipeline and causing condensation is greatly reduced, thereby reducing the risk of pipeline blockage. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The figure shows a schematic structural diagram of a yellow phosphorus production system according to the present invention.

[0032] Figure 2 A schematic diagram showing a heating device in the yellow phosphorus production system of the present invention is shown.

[0033] Description of Reference Numerals

[0034] 1 industrial furnace; 11 first flue gas conveying pipe; 111 first control valve; 112 pressure transmitter; 12 second flue gas conveying pipe; 121 temperature transmitter; 13 third flue gas conveying pipe; 131 second control valve; 132 variable frequency fan;

[0035] 2. Heating device;

[0036] 3 bag dust collector; 31 dust collecting part; 32 filter part;

[0037] 4 circulation pipeline; 41 circulation fan; 42 third control valve; 43 fourth control valve;

[0038] 5 nitrogen supply pipe; 51 fifth control valve;

[0039] 6 air supply pipe; 61 sixth control valve;

[0040] 7 ash discharge device; 71 ash discharge hopper; 72 ash discharge valve;

[0041] 8 dust cleaning device; 81 air supply unit; 82 heating unit; 83 dust cleaning air pipe; 84 pulse valve. DETAILED DESCRIPTION

[0042] To make the technical solutions and beneficial effects of the present invention more clearly understood, the following is a detailed description by listing specific embodiments. Unless otherwise defined, the technical and scientific terms used herein have the same meanings as those in the technical field to which this application belongs.

[0043] In the description of the present invention, unless otherwise expressly defined, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "height", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of simplifying the description of the present invention, and do not indicate that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and should not be understood as a limitation to the present invention.

[0044] In this disclosure, the terms "first" and "second" are used solely for descriptive clarity and should not be construed as indicating the relative importance of the features indicated or the quantity of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly include at least one such feature. In the description of this disclosure, "plurality" means at least two, and "several" means at least one, unless expressly specified otherwise.

[0045] In the present invention, unless otherwise expressly defined, the terms "installed," "connected," "connect," "fixed," and "disposed" should be understood broadly. For example, "connection" can mean fixed connection, removable connection, or integral molding; it can be mechanical or electrical; it can be direct or indirect through an intermediary; it can also refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on the specific circumstances.

[0046] In the present invention, unless otherwise clearly defined, when a first feature is “on,” “above,” “above,” “above,” “below,” “below,” or “below” a second feature, the first feature and the second feature may be in direct contact, or the first feature and the second feature may be in indirect contact via an intermediate medium. Moreover, when a first feature is “on,” “above,” or “above” a second feature, it may mean that the first feature is directly above or obliquely above the second feature, or simply means that the horizontal height of the first feature is higher than the horizontal height of the second feature. When a first feature is “below,” “below,” or “below” a second feature, it may mean that the first feature is directly below or obliquely below the second feature, or simply means that the horizontal height of the first feature is lower than the horizontal height of the second feature.

[0047] The following is based on Figures 1 to 2 The specific embodiment of the yellow phosphorus production system according to the present invention is described in detail.

[0048] In this embodiment, if Figure 1 As shown, the yellow phosphorus production system according to the present invention includes an industrial furnace 1, a heating device 2, a bag filter 3, a circulation pipe 4, a nitrogen supply pipe 5, an air supply pipe 6, an ash removal device 7, and an ash cleaning device 8. The industrial furnace 1 and the heating device 2 are connected via a first flue gas duct 11, the heating device 2 and the bag filter 3 are connected via a second flue gas duct 12, and the bag filter 3 and the spray device (not shown) are connected via a third flue gas duct 13.

[0049] In this embodiment, industrial furnace 1 can be a yellow phosphorus electric furnace for producing yellow phosphorus fume. Heating device 2 is at least used to heat the yellow phosphorus fume. Optionally, the yellow phosphorus fume is heated to a temperature between 220°C and 280°C. This effectively prevents condensation in yellow phosphorus fume, which typically has a dew point of at least 180°C. Furthermore, the overall gas temperature remains relatively low, resulting in low heating energy consumption for the entire production system and relatively low equipment costs.

[0050] like Figure 2 As shown, heating device 2 can be constructed as an internal heater, inserted vertically into first flue gas duct 11 from the top. First flue gas duct 11 is positioned vertically. This allows yellow phosphorus flue gas to flow through the bottom of the heater and out the side of the heater into second flue gas duct 12. Large particles in the yellow phosphorus flue gas settle directly back into industrial furnace 1 through vertical first flue gas duct 11. This structural design eliminates the need for primary dust collectors such as settling chamber dust collectors, mechanical dust collectors, and impact dust collectors commonly used in the prior art, simplifying the structure of the production system.

[0051] In this embodiment, if Figure 1As shown, the first smoke conveying pipe 11 is provided with a first control valve 111 and a pressure transmitter 112. The first control valve 111 is used to control the on-off of the first smoke conveying pipe 11.

[0052] The second flue gas conveying pipe 12 is provided with a temperature transmitter 121 for detecting whether the temperature of the yellow phosphorus flue gas heated by the heating device 2 reaches a predetermined temperature (for example, above 220° C. and below 280° C.).

[0053] The third flue gas conveying pipe 13 is provided with a second control valve 131 and a variable frequency fan 132. The second control valve 131 is used to control the on-off of the third flue gas conveying pipe 13, and the variable frequency fan 132 is used to discharge the purified yellow phosphorus flue gas.

[0054] In this embodiment, the pressure transmitter 112 and the variable frequency blower 132 are interlockedly controlled, thereby ensuring a slight positive pressure (about 50 Pa) at the outlet of the industrial furnace 1 .

[0055] In this embodiment, if Figure 1 As shown, the circulation duct 4 is provided with a circulation fan 41, a third control valve 42, and a fourth control valve 43. One end of the circulation duct 4 is connected to the first flue gas conveying pipe 11 and is located between the first control valve 111 and the heating device 2, while the other end is connected to the third flue gas conveying pipe 13 and is located between the bag filter 3 and the second control valve 131. The third control valve 42 and the fourth control valve 43 are respectively provided at both ends of the circulation duct 4 and are used to control the on / off state of the circulation duct 4. The circulation fan 41 is provided between the third control valve 42 and the fourth control valve 43 to promote gas flow.

[0056] like Figure 1 As shown, the nitrogen supply pipe 5 is connected to the circulation pipe 4 and is located between the third control valve 42 and the fourth control valve 43, for providing nitrogen to the circulation pipe 4. A fifth control valve 51 is provided on the nitrogen supply pipe 5 for controlling the on-off of the nitrogen supply pipe 5.

[0057] The air supply pipe 6 is connected to the circulation pipe 4 and is located between the third control valve 42 and the fourth control valve 43, and is used to provide air to the circulation pipe 4. The air supply pipe 6 is provided with a sixth control valve 61 for controlling the on-off of the air supply pipe 6.

[0058] In this embodiment, by providing the aforementioned circulation pipeline 4 and nitrogen supply pipe 5, the production system pipelines can be gas-exchanged before the production system officially starts production. Specifically, the first control valve 111 and the fourth control valve 43 can be closed, and the second control valve 131 and the third control valve 42 can be opened to introduce room-temperature nitrogen into the circulation pipeline 4 for gas replacement. Furthermore, after the gas replacement is complete, the second control valve 131 and the fifth control valve 51 can be closed, and the fourth control valve 43 can be opened. The nitrogen in the pipeline can be heated using the heating device 2. At this time, the circulation fan 41 operates to circulate the nitrogen in the pipeline, ultimately heating the nitrogen to a certain temperature, for example, above 220°C and below 280°C. Through this pre-gas replacement and heating, the production system pipelines can be pre-filled with high-temperature nitrogen. Thus, when production officially begins, the possibility of condensation forming on the yellow phosphorus fume emitted from the industrial furnace 1 is greatly reduced, thereby reducing the risk of pipeline blockage.

[0059] In this embodiment, if Figure 1 As shown, the lower part of the bag filter 3 is formed with an ash collecting section 31 for collecting the filtered ash. The ash discharge device 7 includes an ash discharge hopper 71 and an ash discharge valve 72. The ash discharge valve 72 is arranged between the ash collecting section 31 and the ash discharge hopper 71 to control the connection and disconnection between the two. A level meter can be set in the ash collecting section 31 to monitor the amount of ash therein to determine whether discharge is required. When discharge is required, the ash discharge valve 72 can be opened, and the ash in the ash collecting section 31 can enter the ash discharge hopper 71. After cooling in the ash discharge hopper 71, the ash can be collected and sent to the silo. It can be understood that multiple level meters can be set in the ash collecting section 31 as needed to detect different material levels. A level meter can also be set in the ash discharge hopper 71 to monitor the amount of ash therein to determine whether it needs to be further discharged and sent to the silo.

[0060] In this embodiment, a silo top dust collector may be provided on the top of the ash discharge hopper 71, and a screw conveyor or a pneumatic ash conveying device may be provided below. These are all prior arts and will not be described in detail here.

[0061] In this embodiment, if Figure 1As shown, the dust cleaning device 8 includes an air supply unit 81, a heating unit 82, a dust cleaning air pipe 83, and a pulse valve 84. The air supply unit 81 contains compressed nitrogen, the heating unit 82 is used to heat the compressed nitrogen, the air supply unit 81 is connected to the bag filter 3 through the dust cleaning air pipe 83, and the pulse valve 84 is provided on the dust cleaning air pipe 83 to control the on-off of the dust cleaning air pipe. It can be understood that compressed nitrogen can be input into the air supply unit 81, the heating unit 82 can heat the compressed nitrogen to a set temperature, and the pulse valve 84 can be opened at a fixed time to allow the high-temperature compressed nitrogen to enter the bag filter 3, to purge and clean the dust on the filter unit 32 of the bag filter 3, and to ensure the normal operation resistance of the bag filter 3.

[0062] In this embodiment, the air supply unit 81 and the heating unit 82 can be constructed as an integrated heating air bag, but the present invention is not limited thereto. Furthermore, the air supply unit 81 can be equipped with a pressure transmitter, a temperature transmitter, a heat tracing and heat preservation device, a safety valve, and a high-altitude release device, all of which are conventional technologies and will not be further described here.

[0063] The working method of the yellow phosphorus production system according to the present invention is briefly described below.

[0064] In this embodiment, the working method includes: before officially starting production, closing the first control valve 111 and the fourth control valve 43, opening the second control valve 131 and the third control valve 42, and inputting room temperature nitrogen from the nitrogen supply pipe 5 into the entire pipeline of the yellow phosphorus production system for gas replacement;

[0065] After the replacement is complete, the second control valve 131 and the fifth control valve 51 are closed, the fourth control valve 43 is opened, and the heating device 2 is activated to heat the nitrogen in the entire pipeline to a certain temperature (e.g., above 220°C and below 280°C). During this process, the circulating fan 41 operates to circulate the nitrogen throughout the pipeline. This helps to heat the nitrogen to the required temperature more quickly.

[0066] After pre-replacement and heating are complete, formal production can begin. At this time, the circulating fan 41 can be turned off, the variable frequency fan 132 can be turned on, the first control valve 111 and the second control valve 131 can be opened, and the third control valve 42 and the fourth control valve 43 can be closed. During formal production, the dust cleaning device 8 is used for regular cleaning, and the dust discharge device 7 is used for dust discharge.

[0067] After stopping production, the first control valve 111 can be closed, the third control valve 42 can be opened, and nitrogen with a temperature greater than 180°C can be input from the nitrogen supply pipe 5 and the heating device 2 to the entire pipeline of the yellow phosphorus production system for gas replacement to prevent condensation and tar film. After the replacement is completed, the relevant valves and equipment are closed.

[0068] Furthermore, when the equipment needs to be repaired, air is introduced into the circulation pipe 4 from the air supply pipe 6 to replace the nitrogen in the entire pipeline, which is conducive to ensuring safe maintenance.

[0069] By adopting the above technical solution, the yellow phosphorus production system according to the present invention has at least the following advantages:

[0070] (1) In the yellow phosphorus production system of the present invention, by providing a circulation pipe and a nitrogen supply pipe, the gas in the pipeline of the entire production system can be replaced before the formal yellow phosphorus production begins, and the nitrogen in the pipeline can be circulated and heated to a predetermined temperature by a heating device. In this way, after the formal start of production, the possibility of condensation caused by yellow phosphorus fume entering the pipeline is greatly reduced, thereby reducing the risk of pipeline blockage.

[0071] (2) In the yellow phosphorus production system of the present invention, the first flue gas conveying pipe is vertically arranged, and the heater is vertically inserted into the first flue gas conveying pipe directly from the top of the first flue gas conveying pipe. In this way, the yellow phosphorus flue gas can flow through the bottom of the heater and flow into the second flue gas conveying pipe from the side of the heater. Large particles in the yellow phosphorus flue gas are directly settled back into the industrial furnace from the vertically arranged first flue gas conveying pipe. This structural design eliminates the need for primary dust collectors such as settling chamber dust collectors, mechanical dust collectors, and impact dust collectors commonly used in the prior art, thereby simplifying the structure of the production system.

[0072] (3) In the yellow phosphorus production system of the present invention, the pressure transmitter and the variable frequency blower are interlockedly controlled to ensure a slight positive pressure at the outlet of the industrial furnace.

[0073] It should be understood that the above embodiments are exemplary and are not intended to encompass all possible embodiments of the present invention. Various modifications and variations may be made to the above embodiments without departing from the scope of the present invention. Similarly, the various technical features of the above embodiments may be arbitrarily combined to form other embodiments of the present invention that may not be explicitly described. Therefore, the above embodiments merely illustrate several embodiments of the present invention and do not limit the scope of protection of the present invention.

Claims

1. A yellow phosphorus production system, characterized in that: The yellow phosphorus production system comprises: Industrial furnaces for producing yellow phosphorus fume; A first flue gas conveying pipe is provided with a first control valve; a heating device connected to the industrial furnace via the first flue gas conveying pipe, and at least used to heat the yellow phosphorus flue gas; a bag filter connected to the heating device via a second flue gas conveying pipe; a third flue gas conveying pipe provided with a second control valve, one end of which is connected to the bag filter and the other end of which is connected to the spraying device; a circulation pipe, one end of which is connected to the first flue gas conveying pipe and is located between the heating device and the first control valve, and the other end of which is connected to the third flue gas conveying pipe and is located between the bag filter and the second control valve, the circulation pipe being provided with a third control valve and a fourth control valve; the third control valve and the fourth control valve being respectively provided at both ends of the circulation pipe and both being used to control the on-off state of the circulation pipe; an air supply pipe connected to the circulation pipe and located between the third control valve and the fourth control valve; and a nitrogen supply pipe, used for inputting nitrogen for replacement, the nitrogen supply pipe being connected to the circulation pipe and being located between the third control valve and the fourth control valve; The circulation pipeline is provided with a circulation fan, and when the heating device heats the nitrogen, the circulation fan works to circulate the nitrogen in the entire pipeline; The third flue gas conveying pipe is provided with a variable frequency fan, which is arranged between the bag dust collector and the second control valve; the first flue gas conveying pipe is provided with a pressure transmitter, which is interlocked with the variable frequency fan; Before officially starting production, the first control valve and the fourth control valve are closed, the second control valve and the third control valve are opened, and nitrogen at room temperature is input from the nitrogen supply pipe to the entire pipeline of the yellow phosphorus production system for gas replacement; after the replacement is completed, the second control valve is closed, the fourth control valve is opened, and the heating device is started to heat the nitrogen in the entire pipeline to a predetermined temperature; after completing the pre-replacement and heating, the production is started, and during the startup production, the third control valve and the fourth control valve are both in a closed state; After stopping production, the first control valve is closed, the third control valve is opened, and nitrogen with a temperature greater than 180° C. is introduced from the nitrogen supply pipe and the heating device into the entire pipeline of the yellow phosphorus production system for gas replacement; and when the equipment is being repaired, air is introduced from the circulation pipe to replace the nitrogen in the entire pipeline; The first smoke conveying pipe is vertically arranged, and the heating device is vertically inserted into the first smoke conveying pipe from the top of the first smoke conveying pipe.

2. The yellow phosphorus production system according to claim 1, wherein The circulation pipeline is provided with a circulation fan, and the circulation fan is provided between the third control valve and the fourth control valve.

3. The yellow phosphorus production system according to claim 1, wherein It also includes an ash discharge device, which includes an ash discharge hopper. The ash discharge hopper is connected to the lower end of the bag dust collector and is used to receive the ash in the bag dust collector.

4. The yellow phosphorus production system according to claim 1, wherein It also includes a cleaning device, which includes an air supply part, a heating part, a cleaning air pipe and a pulse valve. The air supply part contains compressed nitrogen, the heating part is used to heat the compressed nitrogen, the air supply part is connected to the bag dust collector through the cleaning air pipe, and the pulse valve is arranged on the cleaning air pipe.

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