Method and apparatus for heating the charge in a yellow phosphorus electric furnace using the combustion heat of yellow phosphorus tail gas

Abstract

This invention discloses a method and apparatus for heating the charge feed into a yellow phosphorus electric furnace using the combustion heat of yellow phosphorus tail gas. First, the yellow phosphorus tail gas is premixed with combustion air and then enters the gas combustion chamber for combustion, forming a medium-high temperature flue gas flow. Air is blown into the flue gas duct to mix with the medium-high temperature flue gas, and after temperature adjustment, it enters the heating and insulation silo. The medium-high temperature flue gas flows from bottom to top into the heating and insulation silo through the flue gas duct. A mixture of phosphate rock, carbonaceous reducing agent, and silica is added to the heating and insulation silo through the feed inlet. The mixed charge feed moves from top to bottom and is heated by the medium-high temperature flue gas flowing from bottom to top. After heat exchange, the medium-high temperature flue gas cools down to ambient temperature, passes through a dust collection hood, is drawn out by a dust removal fan, and is sent to a bag filter for dust removal before being discharged through the chimney. The heated charge feed enters the yellow phosphorus electric furnace through the feed pipe. This invention solves the problem of efficient utilization of yellow phosphorus tail gas in the prior art, realizes the hot charging configuration of the charge feed for yellow phosphorus production, and achieves energy saving and consumption reduction.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of yellow phosphorus furnace raw material preparation and treatment and yellow phosphorus tail gas waste heat utilization, and particularly relates to a device and method for heating yellow phosphorus furnace raw material by using yellow phosphorus tail gas combustion heat. BACKGROUND

[0002] At present, the electric furnace method is the main process for phosphorus production at home and abroad. In the process of electric furnace method for phosphorus production, yellow phosphorus tail gas mainly composed of CO is generated. The traditional process is to discharge the yellow phosphorus tail gas into the atmosphere after combustion, which causes energy waste and environmental pollution. With the increasingly strict environmental protection policy in China, the method of yellow phosphorus tail gas combustion and emission has been unable to meet the latest requirements of the state for energy saving and emission reduction of electric furnace method for phosphorus production.

[0003] In order to ensure the smooth progress of production, the production enterprises of electric furnace method for phosphorus production currently adopt the methods of yellow phosphorus tail gas combustion for power generation and drying of raw materials. The yellow phosphorus tail gas combustion for power generation needs to be matched with a gas boiler, a steam turbine and a generator set, a supporting plant, equipment and professional personnel. For yellow phosphorus production enterprises, especially small and medium-sized yellow phosphorus production enterprises, the investment is high, the operation and maintenance are complex, the benefits cannot cover the cost, and the economic feasibility is poor. The flue gas required for drying materials is only about 105℃, and the CO content of yellow phosphorus tail gas is more than 85%, so the energy is used in a high-quality and low-quality way.

[0004] Some people have also tried to set a burner in the mixing bin of the electric furnace plant to directly combust the yellow phosphorus tail gas in the mixing bin to heat the raw material, so as to reduce the electric consumption of the electric furnace and realize the energy saving utilization of the yellow phosphorus tail gas. However, this method is easy to ignite the carbonaceous reducing agent in the raw material and the combustible gas that can rise, causing carbon loss and safety hazards.

[0005] In summary, the efficient utilization of yellow phosphorus tail gas has been a technical problem difficult to solve in the electric furnace method for phosphorus production. SUMMARY

[0006] In order to solve the above problems, the present application provides a method for heating yellow phosphorus furnace raw material by using yellow phosphorus tail gas combustion heat, which solves the problem of efficient utilization of yellow phosphorus tail gas in the existing phosphorus production technology, realizes the hot charging configuration of yellow phosphorus production raw material, and achieves the effect of energy saving and consumption reduction.

[0007] The method for heating yellow phosphorus furnace raw material by using yellow phosphorus tail gas combustion heat is as follows:

[0008] (1) The yellow phosphorus tail gas is premixed with the combustion air provided by the combustion air fan according to a certain proportion to form a mixed gas, and then the mixed gas is introduced into the coal gas combustion chamber;

[0009] (2) The mixed gas of yellow phosphorus tail gas and combustion air is combusted in the coal gas combustion chamber to form high-temperature flue gas, and then the high-temperature flue gas flows out through the flue gas pipeline;

[0010] (3) The temperature control mixed air fan blows air into the flue gas pipeline to mix with the medium-high temperature flue gas, and the temperature of the medium-high temperature flue gas is stabilized at 200-600 DEG C.

[0011] (4) The medium-high temperature flue gas stabilized in temperature enters the heating and heat preservation stock bin through the flue gas pipeline, and the mixed charging material composed of phosphorite, carbonaceous reducing agent and silica is added into the heating and heat preservation stock bin from the charging port of the heating and heat preservation stock bin by the charging vehicle, and the mixed charging material moves from top to bottom in the heating and heat preservation stock bin and is heated to 150-550 DEG C by the medium-high temperature flue gas moving from bottom to top, and after the medium-high temperature flue gas and the mixed charging material complete the gas-solid heat exchange, the temperature is reduced to become normal temperature flue gas.

[0012] (5) The normal temperature flue gas is guided out by the dust removal fan through the dust collecting cover located at the upper part of the heating and heat preservation stock bin, is dusted in the bag dust collector and is discharged by the chimney after dust removal; the charging material heated to the specified temperature enters the yellow phosphorus electric furnace from the heating and heat preservation stock bin.

[0013] The yellow phosphorus tail gas and the combustion air are premixed before entering the coal gas combustion chamber to realize the full combustion of the yellow phosphorus tail gas; the coal gas combustion chamber is used to complete the combustion reaction of the yellow phosphorus tail gas and the combustion air and generate medium-high temperature flue gas, and the medium-high temperature flue gas and the mixed charging material complete the gas-solid heat exchange in the heating and heat preservation stock bin to realize the utilization of the yellow phosphorus tail gas combustion heat.

[0014] The mixing ratio of the yellow phosphorus tail gas and the combustion air is determined according to the medium-high temperature flue gas temperature set value, the medium-high temperature flue gas temperature set value is determined according to the type of the carbonaceous reducing agent in the mixed charging material, the carbonaceous reducing agent includes but is not limited to coke, bituminous coal, anthracite and the like, and the range of the medium-high temperature flue gas temperature set value is 200-600 DEG C.

[0015] The temperature of the medium-high temperature flue gas formed by combustion in the coal gas combustion chamber and the medium-high temperature flue gas temperature set value have a deviation, and the air is blown into the flue gas pipeline by the temperature control mixed air fan to mix with the medium-high temperature flue gas to adjust and correct.

[0016] Another object of the present application is to provide a device for completing the above method, which comprises a combustion air fan, a yellow phosphorus tail gas pipe, a coal gas combustion chamber, a temperature control mixed air fan, a heating and heat preservation stock bin, a charging vehicle, a dust collecting cover, a discharging pipe, a dust removal fan, a bag dust collector and a chimney; the combustion air fan and the yellow phosphorus tail gas pipe are connected with the coal gas combustion chamber through a pipeline, the coal gas combustion chamber is connected with the heating and heat preservation stock bin through a flue gas pipeline, and the temperature control mixed air fan is arranged on the flue gas pipeline and is close to the heating and heat preservation stock bin; the dust collecting cover is arranged above the heating and heat preservation stock bin and is sealingly connected with the upper part of the heating and heat preservation stock bin, the charging vehicle is arranged above the heating and heat preservation stock bin and is located in the dust collecting cover and is used for uniformly adding the charging material into the heating and heat preservation stock bin; the dust collecting cover is connected with the bag dust collector through the dust removal fan and a pipeline, the bag dust collector is connected with the chimney, and the bottom of the heating and heat preservation stock bin is communicated with the yellow phosphorus electric furnace through the discharging pipe.

[0017] The heating and heat-preserving stock bin is a container for storing the mixed charging material, and is also a heat exchanger for directly exchanging heat between the high-temperature flue gas and the mixed charging material, so as to realize the heat transfer from the high-temperature flue gas to the mixed charging material.

[0018] The heating and heat-preserving stock bin comprises a bin body, a hopper and a wind distribution mechanism, the bin body is provided with a charging port at the top, two or more hoppers are fixed at the bottom of the bin body, and one wind distribution mechanism is arranged on one side of each hopper, the wind distribution mechanism comprises a main air pipe, a branch pipe group and a temperature sensor, the branch pipe group comprises two or more middle branch pipes of the hoppers and one bottom branch pipe of the hopper, the middle branch pipes of the hoppers are arranged on the main air pipe and located at the middle of the hoppers and in communication with the main air pipe, the bottom branch pipe of the hopper is arranged on the main air pipe and located at the bottom of the hopper and in communication with the main air pipe, one end of the main air pipe is provided with an opening for the high-temperature flue gas inlet, and the other end is closed, and the temperature sensor is arranged at the high-temperature flue gas inlet, and the hopper is provided with a discharging port at the bottom.

[0019] The heating and heat-preserving stock bin further comprises a plurality of mounting supports arranged outside the top end of the bin body, and the heating and heat-preserving stock bin is fixed on the charging layer platform of the plant through the mounting supports.

[0020] The bin body, the hopper and the wind distribution mechanism are all provided with a conventional heat insulation layer outside, the bin body and the hopper are provided with reinforcing ribs on the outer walls, and the materials of the bin body, the hopper and the wind distribution mechanism are selected according to the set value of the high-temperature flue gas temperature and are all high-temperature flue gas resistant materials.

[0021] The combustion-supporting air fan and the temperature-controlling air mixing fan are both frequency-adjustable fans, and the air volume can be adjusted by adjusting the frequency of the fan.

[0022] The application range of the method of the application includes but is not limited to the electric furnace method for producing phosphorus, and the method is also applicable to other electric furnace smelting processes of solid mineral charging materials, the method of using the high-temperature flue gas formed after the combustion of the combustible gas or directly using the high-temperature flue gas to heat the charging material in the stock bin to realize the hot charging and energy saving of the charging material, and all of the above are within the protection scope of the application.

[0023] The application has the advantages of solving the problem of efficient utilization of the yellow phosphorus tail gas in the prior art and realizing the hot charging and configuration of the charging material in the yellow phosphorus production. BRIEF DESCRIPTION OF DRAWINGS

[0024] Fig. 1 FIG. 1 is a structural schematic view of the energy-saving device for heating the charging material in the yellow phosphorus production by using the yellow phosphorus tail gas combustion heat according to the application;

[0025] Fig. 2 FIG. 3 is a structural schematic view of the heating and heat-preserving stock bin from different perspectives;

[0026] Fig. 3 FIG. 4 is a structural schematic view of the wind distribution mechanism in the heating and heat-preserving stock bin from different perspectives;

[0027] In the figure: 1-combustion air fan, 2-yellow phosphorus tail gas pipe, 3-gas combustion chamber, 4-temperature control mixed air fan, 5-heating and heat preservation bin, 5-1-feeding port, 5-2-installation support, 5-3-bin body, 5-4-cone hopper, 5-5-air distribution mechanism, 5-5-1-medium high temperature flue gas inlet, 5-5-2-main air pipe, 5-5-3-cone hopper middle branch pipe, 5-5-4-cone hopper bottom branch pipe, 5-5-5-temperature sensor, 5-6-discharge port, 6-distributing car, 7-dust collecting cover, 8-discharging pipe, 9-yellow phosphorus electric furnace, 10-dust removal fan, 11-bag-type dust collector, 12-chimney. DETAILED DESCRIPTION

[0028] In order to make the personnel in the technical field better understand the present application scheme, the technical scheme in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0029] Example 1: as Figs. 1-3As shown, the device for heating yellow phosphorus furnace charging material by using yellow phosphorus tail gas combustion heat in the embodiment comprises combustion air fan 1, yellow phosphorus tail gas pipe 2, coal gas combustion chamber 3, temperature control mixed air fan 4, heating and heat preservation material bin 5, material distribution vehicle 6, dust collecting hood 7, discharging pipe 8, dust removal fan 10, bag type dust collector 11 and chimney 12. The combustion air fan 1 and the yellow phosphorus tail gas pipe 2 are connected with the coal gas combustion chamber 3 through a pipeline, the coal gas combustion chamber 3 is connected with the heating and heat preservation material bin 5 through a flue gas pipeline, the heating and heat preservation material bin 5 comprises bin body 5-3, cone hopper 5-4 and air distribution mechanism 5-5, the bin body 5-3 is provided with feeding port 5-1 at the top, four cone hoppers 5-4 are fixed at the bottom of the bin body 5-3, and one air distribution mechanism 5-5 is arranged on one side of each cone hopper 5-4. The air distribution mechanism 5-5 comprises main air pipe 5-5-2, branch pipe group and temperature sensor 5-5-5. The branch pipe group comprises three cone middle part branch pipes 5-5-3 and one cone bottom part branch pipe 5-5-4. The cone middle part branch pipes 5-5-3 are arranged on the main air pipe 5-5-2 and located at different positions in the middle part of the cone hopper 5-4 and are in communication with the main air pipe. The cone bottom part branch pipe 5-5-4 is arranged on the main air pipe 5-5-2 and located at the bottom of the cone hopper 5-4 and is in communication with the main air pipe. One end of the main air pipe 5-5-2 is provided with medium-high temperature flue gas inlet 5-5-1, and the other end is closed. The temperature sensor 5-5-5 is arranged at the medium-high temperature flue gas inlet 5-5-1. The cone hopper 5-4 is provided with discharging port 5-6 at the bottom. The temperature control mixed air fan 4 is arranged on the flue gas pipeline and close to the high temperature flue gas inlet 5-5-1 of the heating air distribution mechanism. The dust collecting hood 7 is arranged above the heating and heat preservation material bin 5 and is in sealing connection with the upper part of the heating and heat preservation material bin, so as to cover the upper area of the heating and heat preservation material bin 5. The material distribution vehicle 6 is arranged above the feeding port of the bin body 5-3 and located in the dust collecting hood, and is used for uniformly adding the charging material into the bin body. The dust collecting hood 7 is connected with the bag type dust collector 11 through the dust removal fan 10 and a pipeline. The dust removal fan 10 provides negative pressure to lead the dust-containing normal temperature flue gas in the dust collecting hood 7 out and into the bag type dust collector 11. The bag type dust collector 11 is connected with the chimney 12. The bottom of the heating and heat preservation material bin 5 is communicated with the yellow phosphorus furnace 9 through the discharging pipe 8. The combustion air fan and the temperature control mixed air fan are frequency conversion fans. The bin body 5-3, the cone hopper 5-4 and the air distribution mechanism 5-5 are externally provided with heat preservation layers. The bin body 5-3 and the cone hopper 5-4 are externally provided with structure reinforcing ribs.

[0030] The use steps of the above device are as follows:

[0031] (1) The yellow phosphorus tail gas is premixed with the combustion air provided by the combustion air fan 1 according to the volume ratio of 1:12 to form a mixed gas, and then enters the coal gas combustion chamber 3.

[0032] (2) The mixed gas of the yellow phosphorus tail gas and the combustion air is combusted in the coal gas combustion chamber to form medium-high temperature flue gas, and then flows out through the flue gas pipeline.

[0033] (3) The temperature control mixed air fan 4 blows air into the flue gas pipeline to mix with the high-temperature flue gas, and the temperature of the high-temperature flue gas is stabilized at 500℃; the temperature-stabilized high-temperature flue gas enters the furnace body 5-3 and the hopper 5-4 from the high-temperature flue gas inlet 5-5-1 of the air distribution mechanism through the flue gas pipeline, and the mixed charging material prepared by mixing phosphorite, carbonaceous reducing agent (coke) and silica is added into the furnace body 5-3 from the charging port 5-1 of the furnace body 5-3 by the charging vehicle 6, and the charging material moves from top to bottom in the furnace body 5-3 and the hopper 5-4 and is heated to 450℃ by the high-temperature flue gas flowing from bottom to top; after the high-temperature flue gas and the mixed charging material complete the heat exchange between gas and solid, the temperature of the high-temperature flue gas is reduced, and the high-temperature flue gas becomes normal-temperature flue gas;

[0034] (4) The normal-temperature flue gas is guided by the dust collection hood 7 located at the upper part of the heating and heat preservation stock bin 5, is introduced into the bag-type dust collector 11 by the dust removal fan 10 after dust removal, and is discharged by the chimney 12; the heated charging material enters the yellow phosphorus electric furnace 9 from the discharge port 5-6 of the hopper 5-4 through the discharge pipe 8;

[0035] The temperature sensor 5-5-5 is associated with the temperature control mixed air fan 4 through a controller, and the air volume of the temperature control mixed air fan 4 is adjusted according to the measured value, and the specific method is as follows:

[0036] Step (1), the measured value of the high-temperature flue gas temperature detected by the temperature sensor 5-5-5 is compared with the set value of the high-temperature flue gas temperature;

[0037] Step (2), if the absolute value of the difference between the measured value of the high-temperature flue gas temperature and the set value of the high-temperature flue gas temperature is less than or equal to the set deviation, the frequency of the temperature control mixed air fan 4 is not adjusted, and the air volume is kept unchanged;

[0038] Step (3), if the absolute value of the difference between the measured value of the high-temperature flue gas temperature and the set value of the high-temperature flue gas temperature is greater than the set deviation and the difference is a positive value, the frequency of the temperature control mixed air fan 4 is increased by one gear, and the air volume is increased;

[0039] Step (4), if the absolute value of the difference between the measured value of the high-temperature flue gas temperature and the set value of the high-temperature flue gas temperature is greater than the set deviation and the difference is a negative value, the frequency of the temperature control mixed air fan 4 is decreased by one gear, and the air volume is decreased;

[0040] Step (5), after a delay time, it is judged again whether the absolute value of the difference between the measured value of the high-temperature flue gas temperature and the set value of the high-temperature flue gas temperature is greater than the set deviation, if the absolute value of the difference between the measured value of the high-temperature flue gas temperature and the set value of the high-temperature flue gas temperature is greater than the set deviation and the difference is a positive value, step (3) is executed, if the absolute value of the difference between the measured value of the high-temperature flue gas temperature and the set value of the high-temperature flue gas temperature is greater than the set deviation and the difference is a negative value, step (4) is executed, and if the absolute value of the difference between the measured value of the high-temperature flue gas temperature and the set value of the high-temperature flue gas temperature is less than or equal to the set deviation, step (2) is executed;

[0041] Wherein, the deviation is set according to the actual working condition, the value range is (3%-10%); the delay time is (1.1-1.3) times of the time required for the medium-high temperature flue gas to flow from the mixing position to the temperature sensor 5-5-5 position.

[0042] The above description of disclosed embodiments enables one of ordinary skill in the art to make or use the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Therefore, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for heating yellow phosphorus furnace charge with yellow phosphorus tail gas combustion heat, characterized in that, The steps are as follows: (1) the yellow phosphorus tail gas is premixed with combustion air to form a mixed gas, which is then introduced into a gas combustion chamber, and the mixed gas is combusted in the gas combustion chamber to form high-temperature flue gas, which flows out through a flue gas pipeline; (2) air is introduced into the flue gas pipeline to mix with the high-temperature flue gas, so that the temperature of the high-temperature flue gas is stabilized at 200-600℃; (3) the high-temperature flue gas with a stabilized temperature is introduced into a heating and heat-insulating stock bin from bottom to top, and the mixed charging material of phosphorite, carbonaceous reducing agent and silica is introduced into the heating and heat-insulating stock bin from the charging material inlet of the heating and heat-insulating stock bin by a charging vehicle, and the mixed charging material moves from top to bottom in the heating and heat-insulating stock bin and is heated to 150-550℃ by the high-temperature flue gas flowing from bottom to top, and the high-temperature flue gas is cooled to become normal-temperature flue gas after completing the gas-solid heat exchange with the mixed charging material; (4) the normal-temperature flue gas is introduced into a bag-type dust collector by a dust removal fan through a dust collection hood located at the upper part of the heating and heat-insulating stock bin, and is discharged through a chimney after being cleaned by the bag-type dust collector; and the heated charging material is introduced into a yellow phosphorus electric furnace through a discharging pipe from the heating and heat-insulating stock bin.

2. The method for heating the charging material of the yellow phosphorus electric furnace by using the combustion heat of yellow phosphorus tail gas according to claim 1, characterized in that: The carbonaceous reducing agent includes one of coke, bituminous coal or anthracite.

3. An apparatus for carrying out the method of heating the charge of a yellow phosphorus electric furnace with the heat of combustion of the yellow phosphorus tail gas as claimed in claim 1, characterized in that: The device comprises a combustion air fan (1), a yellow phosphorus tail gas pipe (2), a gas combustion chamber (3), a temperature control and air mixing fan (4), a heating and heat-insulating stock bin (5), a charging vehicle (6), a dust collection hood (7), a discharging pipe (8), a dust removal fan (10), a bag-type dust collector (11) and a chimney (12); the combustion air fan (1) and the yellow phosphorus tail gas pipe (2) are connected with the gas combustion chamber (3) through a pipeline, the gas combustion chamber (3) is connected with the heating and heat-insulating stock bin (5) through a flue gas pipeline, and the temperature control and air mixing fan (4) is arranged on the flue gas pipeline and close to the heating and heat-insulating stock bin; the dust collection hood (7) is arranged above the heating and heat-insulating stock bin (5) and is sealingly connected with the upper part of the heating and heat-insulating stock bin, the charging vehicle (6) is arranged above the heating and heat-insulating stock bin (5) and is located in the dust collection hood, and is used for uniformly introducing the charging material into the heating and heat-insulating stock bin (5); the dust collection hood (7) is connected with the bag-type dust collector (11) through the dust removal fan (10) and a pipeline, the bag-type dust collector (11) is connected with the chimney (12), and the bottom of the heating and heat-insulating stock bin (5) is communicated with the yellow phosphorus electric furnace (9) through the discharging pipe (8).

4. The apparatus of claim 3, wherein: The heating and heat preservation stock bin (5) comprises a bin body (5-3), a hopper (5-4) and a air distribution mechanism (5-5). The bin body (5-3) is provided with a feeding port (5-1) at the top. Two or more hoppers (5-4) are fixed at the bottom of the bin body (5-3). Each hopper (5-4) is provided with an air distribution mechanism (5-5) on one side. The air distribution mechanism (5-5) comprises a main air pipe (5-5-2) and a branch pipe group, and a temperature sensor (5-5-5). The branch pipe group comprises two or more middle hopper branch pipes (5-5-3) and one bottom hopper branch pipe (5-5-4). The middle hopper branch pipes (5-5-3) are installed on the main air pipe (5-5-2) and located in the middle of the hopper (5-4) and communicate with the main air pipe. The bottom hopper branch pipe (5-5-4) is installed on the main air pipe (5-5-2) and located at the bottom of the hopper (5-4) and communicates with the main air pipe. One end of the main air pipe (5-5-2) is provided with a medium-high temperature flue gas inlet (5-5-1), and the other end is closed. The temperature sensor (5-5-5) is arranged at the medium-high temperature flue gas inlet (5-5-1). The hopper (5-4) is provided with a discharging port (5-6) at the bottom.

5. The apparatus of claim 4, wherein: The heating and heat preservation stock bin further comprises a mounting support (5-2). A plurality of mounting supports (5-2) are arranged outside the top end of the bin body (5-3). The heating and heat preservation stock bin (5) is fixed on the loading layer platform of the factory building through the mounting supports.

6. The apparatus of claim 3, wherein: The combustion air fan (1) and the temperature control mixed air fan (4) are frequency conversion fans.

7. The apparatus of claim 4, wherein: The bin body (5-3), the hopper (5-4) and the air distribution mechanism (5-5) are all provided with an external heat preservation layer.

Images