Coal injection distributor and low-pressure safe pressure supplementing system for spray gun

Abstract

The utility model provides a coal injection distributor and spray gun low pressure safety pressure supplementing system, which comprises a pressure stabilizing gas supplementing main pipe and a plurality of branch gas supplementing pipes, the pressure stabilizing gas supplementing main pipe is communicated with each branch gas supplementing pipe, at least one branch gas supplementing pipe is connected with the bottom of a distributor large pipe, and the distributor large pipe is communicated with the branch gas supplementing pipes. The other branch blowdown pipes are connected with the branch pipes at the rear end of the distributor; pressure transmitters are respectively arranged on the pressure-stabilizing air supply main pipe and the distributor large pipe; another pressure transmitter is also arranged between the spray gun and a connecting node of the distributor rear-end branch pipe and the branch air supply pipe; each branch air supplementing pipe is provided with a pneumatic stop valve, a check valve and a manual stop valve, and the branch air supplementing pipe connected with the distributor large pipe is further provided with a pressure adjusting valve. According to the utility model, real-time monitoring and rapid supplement of pressure in the coal injection process are realized, potential safety hazards and production problems caused by insufficient pressure are effectively avoided, the safety and reliability of the coal injection process are improved, and meanwhile, the production cost is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to ironmaking blast furnace coal powder injection technical field, concretely relates to a coal injection distributor and low pressure safety pressure compensation system of lance. BACKGROUND

[0002] The technological process that coal powder is injected into blast furnace is as follows: coal powder first enters injection tank, then is transmitted to coal powder distributor through coal injection big pipe, and finally reaches blast furnace tuyere through distributor branch pipe, hose and lance.

[0003] According to "ironmaking safety regulations" (AQ2002-2018), in the process of injecting coal into blast furnace, the injection tank pressure must be strictly controlled to ensure that the injection outlet pressure exceeds the blast furnace hot air pressure by 0.05MPa. If this condition cannot be met, injection should be stopped immediately. In the production process, if the lance outlet pressure is insufficient (such as less than the tuyere hot air pressure), high-temperature hot air (about 1200 DEG C) will flow backward into the lance pipe from the lance nozzle, burning the connecting hose between the lance and the coal powder distributor branch pipe. This may cause a large amount of high-pressure high-temperature hot air to be ejected from the lance pipe with red-hot coke fines, burning the blowpipe and causing safety accidents. In addition, high-pressure high-temperature hot air containing a large amount of oxygen may also flow backward into the coal injection pipeline and burn with coal powder, causing safety accidents such as fire and explosion.

[0004] In the current coal injection process design, when the blast furnace tuyere hot air pressure remains constant, the lance outlet pressure is mainly affected by the front-end injection tank pressure (tank pressure) and the coal injection pipeline resistance loss. The adjustment of coal injection quantity mainly depends on the pressure difference between the injection tank pressure and the blast furnace tuyere hot air pressure. Increasing the coal injection quantity requires increasing the pressure difference, i.e. increasing the tank pressure, thereby increasing the lance outlet pressure; reducing the coal injection quantity requires reducing the pressure difference, which accordingly reduces the tank pressure, resulting in a decrease in the lance outlet pressure, and there is a one-to-one correspondence between the coal injection quantity and the pressure difference.

[0005] However, the existing coal injection process has many defects: when the blast furnace is not in order and requires low coal injection quantity, the low tank pressure causes the lance outlet pressure to be insufficient, which cannot meet the safety requirements; increasing the injection tank pressure will also cause excessive coal injection quantity, which violates the production requirements. The commonly used method of increasing secondary air flow has a lagging response and is prone to wear the coal injection big pipe. In addition, blockage of the front end of the coal injection big pipe, insufficient pressure of the injection gas source, blockage of the branch pipe inlet by foreign matter, failure of the injection tank coal supply valve, pipeline damage and leakage, and unreasonable design of the inner diameter of the lance and the pipeline, etc. can all easily cause the lance outlet pressure to be lower than the safety requirements, posing safety hazards and operational difficulties for production, and urgent optimization and improvement are needed. Therefore, we propose a coal injection distributor and low pressure safety pressure compensation system for blast furnace to solve the problems existing in the prior art and quickly supplement the pressure in the case of insufficient pressure of the coal powder distributor and lance based on safety. UTILITY MODEL CONTENTS

[0006] The utility model discloses a purpose at providing a coal injection distributor and low pressure safety pressure compensation system of spray gun, to solve the coal injection technology of prior art can not effectively stabilize pressure difference, cause pressure difference fluctuation and cause the influence to coal injection, bring the problem such as safety hidden danger to production.

[0007] To realize above-mentioned purpose, the utility model discloses the following technical scheme: a coal injection distributor and low pressure safety pressure compensation system of spray gun, characterized by, including the main pipe of pressure stabilization and a plurality of branch air supply pipe, the main pipe of pressure stabilization and each branch air supply pipe are communicated, wherein, at least one branch air supply pipe is connected with the bottom of distributor big pipe, forms coal injection big pipe and distributor pressure deficiency rapid pressure compensation part, the rest branch air supply pipe is connected with the distributor rear end branch pipe, forms the rapid pressure compensation part of distributor rear end branch pipe pressure deficiency,

[0008] The main pipe of pressure stabilization, distributor big pipe is provided with pressure transmitter respectively, also be provided with pressure transmitter between the connecting node of branch air supply pipe and the distributor rear end branch pipe and spray gun,

[0009] Each branch air supply pipe is provided with pneumatic cut-off valve, check valve and manual cut-off valve, and the branch air supply pipe connected with the distributor big pipe is also provided with pressure regulating valve.

[0010] Further, one end of the distributor big pipe is connected with the coal injection big pipe, and the other end is connected with the distributor ring pipe, and the distributor rear end branch pipe is connected on the distributor ring pipe.

[0011] Further, the check valve is arranged between the pneumatic cut-off valve and the manual cut-off valve.

[0012] After adopting the above technical scheme, compared with prior art, the following beneficial effects are obtained: the real-time monitoring and rapid replenishment of pressure during the coal injection process are realized, the safety hazards and production problems caused by insufficient pressure are effectively avoided, the safety and reliability of the coal injection process are improved, and the production cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0013] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or prior art, the drawings needed to be used in the embodiment or prior art description will be briefly introduced, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained according to these drawings without the creative labor.

[0014] Figure 1 It is the structure schematic diagram of the utility model.

[0015] Explanation of reference signs: 1, main pipe for pressure stabilization and air supplement; 11, branch pipe for air supplement; 111, pneumatic cut-off valve; 112, check valve; 113, manual cut-off valve; 114, pressure regulating valve; 2, large pipe of distributor; 3, ring pipe of distributor; 31, branch pipe at rear end of distributor; 4, large pipe for coal injection; 5, pressure transmitter. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical scheme and advantages of the utility model clearer and more apparent, the utility model will be further described in detail below in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the utility model and not to limit the utility model.

[0017] In view of the problems existing in the prior art, the utility model provides a coal injection distributor and a low-pressure safety pressure supplement system for a spray gun, aiming at solving the problem of insufficient pressure in the coal injection process in the prior art, ensuring the safety and stability of the coal injection process, meeting the requirements of relevant safety regulations, reducing the influence of pressure difference fluctuation on coal injection, and the utility model will be described in detail below in combination with the drawings.

[0018] Reference Figure 1 The technical scheme adopted by the specific embodiment is shown in the figure: a coal injection distributor and a low-pressure safety pressure supplement system for a spray gun, comprising a main pipe for pressure stabilization and air supplement 1 and a plurality of branch pipes for air supplement 11, wherein the main pipe for pressure stabilization and air supplement is in communication with each branch pipe for air supplement 11.

[0019] Among them, at least one branch pipe for air supplement 11 is connected with the bottom of the large pipe of distributor 2, forming a large pipe for coal injection 4 and a fast pressure supplement part for insufficient pressure of the distributor, while the remaining branch pipes for air supplement 11 are connected with the branch pipe at the rear end of the distributor 31, forming a fast pressure supplement part for insufficient pressure of the branch pipe at the rear end of the distributor 31, one end of the large pipe of distributor 2 is connected with the large pipe for coal injection 4, and the other end is connected with the ring pipe of distributor 3, and the branch pipe at the rear end of the distributor 31 is connected on the ring pipe of distributor 3.

[0020] It should be specifically pointed out that a pressure transmitter 5 should be arranged on the main pipe for pressure stabilization and air supplement and the large pipe of distributor 2, and a pressure transmitter 5 is arranged between the connection node of the branch pipe at the rear end of the distributor 31 and the branch pipe for air supplement 11 and the spray gun.

[0021] Each branch pipe for air supplement 11 is provided with a pneumatic cut-off valve 111, a check valve 112 and a manual cut-off valve 113, and the branch pipe for air supplement 11 connected with the large pipe of distributor 2 is further provided with a pressure regulating valve 114, specifically, the check valve 112 is arranged between the pneumatic cut-off valve 111 and the manual cut-off valve 113.

[0022] The quick pressure compensation part of the coal injection main pipe 4 and the distributor: when the pressure transmitter 5 on the pipe of the distributor main pipe 2 detects that the pressure is lower than a certain set value (for example, 60 kPa), it indicates that the pipe pressure of the coal injection main pipe 4 is insufficient, and the outlet pressure of the lance will be lower than 50 kPa. At this time, the computer program automatically triggers a signal to open the shut-off valve on the branch air supplement pipe 11 connected to the bottom of the distributor main pipe 2. The pressure regulating valve 114 quickly adjusts according to the set pressure range of the distributor to supplement air and pressure, so that the distribution gas pressure stabilizes in the appropriate range. When the system pressure returns to normal and shows an upward trend, the pressure regulating valve 114 slowly reduces the opening until the shut-off valve is closed to prevent large fluctuations in pressure supplementation, thereby affecting the stability of the entire pipe pressure.

[0023] The quick pressure compensation part of the distributor rear-end branch pipe 31: when the distributor overall pressure is normal, but the pressure transmitter 5 of a part of the distributor rear-end branch pipe 31 detects that the pressure of the branch pipe is lower than the safety value, it can be judged that there is a blockage at the inlet of the branch pipe or inside the branch pipe, which causes the outlet pressure of the corresponding lance to not meet the safety requirements. At this time, the computer program automatically opens the pneumatic shut-off valve 111 on the corresponding branch air supplement pipe 11 to quickly pressurize the distributor rear-end branch pipe 31 and increase the outlet pressure of the lance to ensure safety. The size of the pressurization can be pre-adjusted and set by the manual valve.

[0024] If a lance needs to be cooled due to insufficient cooling strength, causing the lance body to droop, the coal powder delivery of the lance does not need to be stopped, and the lance can be supplemented with air through the manual valve on the corresponding branch air supplement pipe 11 to adjust the pressure and flow, thereby enhancing the cooling effect. This method avoids the inflow of a large amount of nitrogen into other lances from the distributor, saves resources, and reduces costs.

[0025] In the production process, if the blast furnace requires low coal injection, a lower tank pressure needs to be set to meet the demand for low coal injection according to the corresponding relationship between pressure difference and coal quantity. However, after setting the tank pressure, due to the influence of pipe resistance loss, the distributor pressure may be too low, causing the pressure of the distributor rear-end branch pipe 31 to be close to the hot blast pressure of the blast furnace, which exists a safety hazard of hot blast backflow and cannot meet the safety requirements. At this time, the computer interlocking program will automatically start to open the shut-off valve on the branch air supplement pipe 11 connected to the distributor main pipe 2 to charge pressure. At this time, the pressure regulating valve 114 on the branch air supplement pipe 11 automatically adjusts according to the pressure value on the distributor within the set pressure range to stabilize the pressure of the distributor and ensure that the pressure of the distributor rear-end branch pipe 31 is higher than the hot blast pressure of the blast furnace by 50 kPa. Since the front-end pressurization will increase the resistance loss of the coal injection main pipe 4, in order to maintain the stability of the coal injection quantity, it is necessary to increase the tank pressure of the injection tank to increase the pressure of the entire coal injection pipe and form a safe pressure difference.

[0026] If the front end pressure of the coal injection main pipe 4 continuously rises and the rear end distributor pressure continuously drops during the coal injection process, the system determines that the front end of the coal injection main pipe 4 is blocked. When the distributor pressure value is lower than the set value, the system automatically opens the cut-off valve on the branch air supply pipe 11 connected to the bottom of the distributor main pipe 2, and then quickly charges the pressure. The pressure regulating valve 114 on the air supply pipe automatically adjusts according to the pressure value on the distributor, within the set pressure range, to stabilize the distributor pressure and prevent hot air from flowing backward.

[0027] If the front end main pipe pressure only slowly rises and the distributor end pressure sharply rises, while the pressure of the rear end branch pipe 31 of the distributor rapidly drops during the coal injection process, it is determined that foreign matter is blocked at the inlet of the rear end distribution branch pipe, causing the front end of the distributor to be blocked. In this case, the branch air supply pipe 11 system connected to the rear end branch pipe 31 of the distributor will automatically open the air supply and charge according to the set requirements, to avoid hot air from flowing backward and burning the hose.

[0028] If the pressure of each system is normal, but the pressure measurement value of the rear end branch pipe 31 of a certain distributor is lower than the safety requirement during the coal injection process, the system determines that there is a slight blockage at the inlet of the branch pipe or a blockage inside the branch pipe. At this time, the branch pipe pressure supply system will automatically open the air supply to avoid hot air from flowing backward into the inside of the lance.

[0029] The utility model realizes the real-time monitoring and rapid replenishment of pressure during the coal injection process, effectively avoids the safety hazards and production problems caused by insufficient pressure, improves the safety and reliability of the coal injection process, and reduces the production cost.

[0030] In the description of the utility model, unless otherwise specified, the meaning of "multiple" is two or more; the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the utility model.

[0031] The above is only used to illustrate the technical scheme of the utility model and is not limited, and other modifications or equivalent replacements of the technical scheme of the utility model made by those skilled in the art should be covered in the scope of the claims of the utility model.

Claims

1. A coal injection distributor and low pressure safety pressure supplementing system for a lance, characterized in that, The device comprises a constant-pressure air supplementing main pipe and a plurality of branch air supplementing pipes, the constant-pressure air supplementing main pipe is communicated with each branch air supplementing pipe, at least one branch air supplementing pipe is connected with the bottom of the distributor main pipe to form a coal injection main pipe and a fast pressure supplementing part of the distributor, and the rest of the branch air supplementing pipes are connected with the distributor rear end branch pipe to form a fast pressure supplementing part of the distributor rear end branch pipe; Pressure transmitters are arranged on the constant-pressure air supplementing main pipe and the distributor main pipe respectively, and a pressure transmitter is arranged between the connecting node of the distributor rear end branch pipe and the branch air supplementing pipe and the lance. A pneumatic cut-off valve, a check valve and a manual cut-off valve are arranged on each branch air supplementing pipe, and a pressure regulating valve is arranged on the branch air supplementing pipe connected with the distributor main pipe.

2. The coal injection distributor and low pressure safety pressure makeup system for lances according to claim 1, characterized in that, One end of the distributor main pipe is connected with the coal injection main pipe, and the other end is connected with the distributor ring pipe, and the distributor rear end branch pipe is connected with the distributor ring pipe.

3. The coal injection distributor and lance pressure low safety pressure makeup system of claim 1, wherein, The check valve is arranged between the pneumatic cut-off valve and the manual cut-off valve.

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