Carbon black raw oil preheater capable of reducing carbon deposition

Abstract

The invention relates to a carbon black raw oil preheater capable of reducing carbon deposition. The carbon black raw oil preheater comprises a raw oil preheater body, a cooling assembly, a sweeping and blowing assembly and a cleaning assembly. The cooling assembly is arranged at the flue gas inlet end of the raw oil preheater and comprises at least two quenching water guns; the sweeping and blowing assembly comprises a sweeping and blowing air valve and at least two sweeping and blowing spray heads, and the sweeping and blowing spray heads are arranged on the inner wall of the raw oil preheater close to the snake-shaped tube nest and connected with the sweeping and blowing air valve through sweeping and blowing pipelines; the cleaning assembly comprises a cleaning scraper blade, a telescopic rod, a fixing plate and a cooling water pipeline, the cleaning scraper blade is of a hollow structure, a through hole allowing the S-shaped tube nest to penetrate through is formed in the cleaning scraper blade, one end of the telescopic rod is connected with the cleaning scraper blade, the other end of the telescopic rod is connected with the fixing plate, and the cooling water pipeline is communicated with the cleaning scraper blade. According to the invention, the flowing speed of the carbon black flue gas in the raw oil preheater can be increased, the carbon deposition on the S-shaped tube nest is effectively reduced, the carbon deposition is cleaned in time, and the heat exchange efficiency of the carbon black hot flue gas and the raw oil is improved.

Description

Technical Field

[0001] The present application relates to the technical field of carbon black production, and in particular to a carbon black feedstock oil preheater capable of reducing carbon deposits. Background Art

[0002] The carbon black feedstock oil preheater is used to preheat the carbon black feedstock oil during the carbon black production process. The carbon black flue gas at the outlet of the carbon black waste heat boiler enters the carbon black feedstock oil preheater, and the carbon black flue gas exchanges heat with the feedstock oil. After the preheating effect is achieved, it enters the carbon black reactor to produce carbon black, and the carbon black flue gas flows to the filter bag for gas-solid separation after secondary rapid cooling. Since the carbon black flue gas contains moisture and carbon black powder, when the carbon black flue gas flows through the feedstock oil preheater, the heat exchange of the tubes causes the flue gas temperature to drop and the speed to drop. The carbon black powder is easily attached to the serpentine tube wall in the feedstock oil preheater after mixing with moisture and forms an accumulation layer. The accumulation layer will affect the heat exchange efficiency of the feedstock oil, resulting in insufficient preheating of the feedstock oil, affecting the atomization and cracking of the feedstock oil to produce carbon black, thereby affecting the quality of the carbon black product and energy saving and consumption reduction. The existing technology usually uses gas blowing to clean the accumulated layer, but since carbon black powder will form a sticky oily substance after mixing with water, the force of gas blowing is weak and it is difficult to effectively clean the accumulated carbon black. Summary of the invention

[0003] The purpose of the present invention is to provide a carbon black feedstock oil preheater that can reduce carbon deposits, increase the flow rate of carbon black flue gas in the feedstock oil preheater, effectively reduce carbon deposits on the serpentine tubes, and clean the carbon deposits in time, thereby improving the heat exchange efficiency between carbon black hot flue gas and feedstock oil.

[0004] The technical solution adopted by the present invention is: a carbon black raw oil preheater capable of reducing carbon deposits, comprising a raw oil preheater, a cooling component, a purge component and a cleaning component; the flue gas inlet end of the raw oil preheater is a closed structure, the cross section of which is shaped like a funnel, and a serpentine tube array is arranged in the raw oil preheater; the cooling component is arranged at the flue gas inlet end of the raw oil preheater, and the cooling component comprises at least two quenching water guns for spraying atomized quenching water into the flue gas inlet end of the raw oil preheater; the purge component comprises a purge air valve and at least two purge nozzles, and the purge nozzles are arranged at the raw oil preheater. The inner wall of the crude oil preheater is close to the position of the serpentine tube array and is connected to the purge air valve through a purge pipe to spray purge air to the serpentine tube array; the cleaning component includes a cleaning scraper, a telescopic rod, a fixed plate and a cooling water pipe. The cleaning scraper is a hollow structure and is arranged in the crude oil preheater. The cleaning scraper is provided with a through hole for the serpentine tube array to pass through. The fixed plate is arranged outside the crude oil preheater. One end of the telescopic rod is connected to the cleaning scraper, and the other end is connected to the fixed plate. The cooling water pipe is connected to the cleaning scraper, and flowing cooling water is injected into the cleaning scraper.

[0005] Furthermore, the edge of the through hole is provided with serrations.

[0006] Furthermore, the travel length of the telescopic rod is less than or equal to the length of a single straight pipe section in the serpentine tube array.

[0007] Furthermore, a pressure sensor is provided at one end of the telescopic rod connected to the fixed plate, for detecting the thrust of the telescopic rod on the cleaning scraper.

[0008] Furthermore, the pressure sensor signal is connected to a monitoring device, and when the pressure sensor signal is greater than a set threshold, the monitoring device sends an alarm signal to stop the telescopic rod from working.

[0009] Furthermore, the quenching water gun and the purge nozzle are evenly spaced around the side wall of the crude oil preheater, the spray angle of the quenching water gun is 10~30°, and the spray angle of the purge nozzle is 15~45°.

[0010] Furthermore, the gas sprayed by the purge nozzle is nitrogen or filtered carbon black smoke. When the gas sprayed by the purge nozzle is nitrogen, a heater is also provided on the purge pipe. The nitrogen is heated by the heater and then sprayed into the crude oil preheater by the purge nozzle.

[0011] The beneficial effects of the present invention are: (1) The present invention sprays quenching water into the flue gas inlet end of the crude oil preheater to reduce the initial temperature of the carbon black flue gas entering the crude oil preheater within a reasonable range. At the same time, the serpentine tubes are swept with nitrogen or filtered carbon black flue gas, thereby increasing the flow rate of the carbon black flue gas in the crude oil preheater and reducing the accumulation of carbon black. In addition, the present invention also regularly scrapes off the carbon black accumulated outside the serpentine tubes by a cleaning scraper to ensure the heat exchange efficiency. (2) The present invention is provided with serrations on the edge of the through hole to prevent the spacing between the through hole and the outer wall of the serpentine tube array from being too small, which would block the cleaning scraper from being blocked by the accumulated carbon black and make it unable to move; circulating cooling water is provided in the cleaning scraper to cool the cleaning scraper and extend the service life of the cleaning scraper in a high temperature environment; the present invention detects the thrust of the telescopic rod on the cleaning scraper through a pressure sensor. When the thrust exceeds a preset value, it indicates that the carbon black accumulation is more serious. A signal is sent to prompt the operator to stop the telescopic rod movement in time to avoid damage to the device, and remind the operator to arrange maintenance work in time to clean the carbon deposits. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0013] Figure 1 It is a structural schematic diagram of an embodiment of the present invention; Figure 2 Schematic diagram of the structure of the cleaning scraper in an embodiment of the present invention.

[0014] Explanation of the accompanying drawings: 1-raw oil preheater, 2-flue gas inlet, 3-quenching water gun, 4-purge air valve, 5-purge nozzle, 6-serpentine tube array, 7-cleaning scraper, 8-telescopic rod, 9-fixed plate, 10-cooling water pipeline, 11-through hole, 12-sawtooth, 13-pressure sensor, 14-heater, 15-boiler, 16-secondary quenching water gun, 17-filter bag, 18-purge pipeline, 19-raw oil inlet valve, 20-raw oil outlet valve, 21-cooling water tank. DETAILED DESCRIPTION

[0015] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention can also be implemented in other ways different from those described herein, and therefore, the present invention is not limited to the limitations of the specific embodiments disclosed below.

[0016] Unless otherwise defined, the technical or scientific terms used herein shall have the usual meanings understood by persons of ordinary skill in the field described in this application. The words "first", "second" and similar terms used in this patent application specification and claims do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "an" do not indicate a quantity limitation, but indicate the existence of at least one. Words such as "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship also changes accordingly.

[0017] like Figure 1~Figure 2As shown, a carbon black feedstock oil preheater capable of reducing carbon deposits comprises a feedstock oil preheater 1, a cooling component, a purge component and a cleaning component. The flue gas inlet end 2 of the feedstock oil preheater 1 is a closed structure, and its cross section is shaped like a funnel, which can accelerate the carbon black flue gas to enter the feedstock oil preheater 1. A serpentine tube array 6 is arranged in the feedstock oil preheater 1. The flue gas contacts the serpentine tube array 6 and performs heat exchange, and the temperature is transferred to the carbon black feedstock oil to preheat the feedstock oil. The cooling component is arranged at the flue gas inlet end 2 of the feedstock oil preheater 1, and the cooling component comprises at least two quenching water guns 3, which are used to spray atomized quenching water into the flue gas inlet end 2 of the feedstock oil preheater 1, reduce the pressure in the feedstock oil preheater 1, and accelerate the speed at which the carbon black flue gas flows through the feedstock oil preheater 1. The purge assembly includes a purge air valve 4 and at least two purge nozzles 5. The purge nozzles 5 are arranged on the inner wall of the crude oil preheater 1 near the position of the serpentine tube 6, and are connected to the purge air valve 4 through a purge pipe 18, and spray purge air to the serpentine tube 6 to clean the carbon black attached to the serpentine tube 6. The cleaning assembly includes a cleaning scraper 7, a telescopic rod 8, a fixed plate 9 and a cooling water pipe 10. The cleaning scraper 7 is a hollow structure and is arranged in the crude oil preheater 1. The cleaning scraper 7 is provided with a through hole 11 for the serpentine tube 6 to pass through. The fixed plate 9 is arranged outside the crude oil preheater 1. One end of the telescopic rod 8 is connected to the cleaning scraper 7, and the other end is connected to the fixed plate 9. The cleaning scraper 7 is moved left and right by the telescopic rod 8 to scrape off the carbon black accumulated on the outer wall of the serpentine tube 6. The cooling water pipe 10 is in communication with the cleaning blade 7 , and flowing cooling water is injected into the cleaning blade 7 , thereby extending the service life of the cleaning blade 7 in a high temperature environment.

[0018] In the embodiment of the present invention, the edge of the through hole 11 is provided with saw teeth 12, which can prevent the cleaning scraper 7 from being blocked by the accumulated carbon black and unable to move due to the small spacing between the through hole 11 and the outer wall of the serpentine tube 6. In order to prevent the cleaning scraper 7 from escaping from the serpentine tube 6 during movement and hitting the serpentine tube 6 to cause damage to the device, in the embodiment of the present invention, the stroke of the telescopic rod 8 is less than or equal to the length of a single straight tube section in the serpentine tube 6, and a pressure sensor 13 is provided at one end of the telescopic rod 8 connected to the fixed plate 9 to detect the thrust of the telescopic rod 8 on the cleaning scraper 7. The signal of the pressure sensor 13 is connected to the monitoring device. When the signal of the pressure sensor 13 is greater than the set threshold, the monitoring device sends an alarm signal to stop the telescopic rod 8 from working, so as to avoid damage to the telescopic rod 8 or the cleaning scraper 7, and the operator needs to arrange maintenance work as soon as possible.

[0019] The working principle of the embodiment of the present invention is as follows: The embodiment of the present invention is installed on the production line, the flue gas inlet end 2 of the crude oil preheater 1 is connected to the boiler 15, and the outlet end is connected to the filter bag 17, and the front end of the filter bag 17 is provided with a secondary quenching water gun 163. The two ends of the serpentine tube 6 of the crude oil preheater 1 are respectively connected to the crude oil inlet valve 19 and the crude oil outlet valve 20, and the cooling water pipeline 10 is connected to the cooling water tank 21. The carbon black flue gas at the boiler 15 enters the crude oil preheater 1 after being accelerated by the closing section. Since the inner diameter of the crude oil preheater 1 is larger than the inner diameter of the flue gas inlet, the carbon black flue gas will increase in volume after entering the crude oil preheater 1. At this time, quenching water is sprayed into the flue gas inlet end 2 of the crude oil preheater 1 through the quenching water gun 3, and the temperature of the carbon black flue gas is appropriately reduced, so that the air pressure of the flue gas inlet end 2 of the crude oil preheater 1 is reduced, thereby increasing the flow rate of the carbon black flue gas. The greater the flow rate of the carbon black flue gas, the less likely it is to accumulate on the outer wall of the serpentine tube 6.

[0020] Since the quenching water has a cooling effect, the quenching water gun 3 can only be set at the front end of the raw oil preheater 1, and cannot be directly sprayed on the serpentine tube 6, otherwise the preheating efficiency of the carbon black raw oil will be reduced, and the serpentine tube 6 will be more likely to adhere to carbon black after being stained with water mist. Therefore, for the straight pipe section of the serpentine tube 6, the purge air is sprayed by the purge nozzle 5 to clean it. Preferably, the gas sprayed by the purge nozzle 5 is nitrogen or carbon black smoke filtered by the filter bag 17. Nitrogen or filtered carbon black smoke will neither react with carbon black smoke in the raw oil preheater 1, nor increase the carbon black content in the carbon black smoke. If nitrogen is selected as the purge gas, in order to avoid the low temperature of nitrogen and affect the heat exchange efficiency at the serpentine tube 6, a heater 14 can be set on the purge pipe 18, and the nitrogen is heated by the heater 14 and sprayed into the raw oil preheater 1 by the purge nozzle 5 for purge. The quenching water gun 3 and the purge nozzle 5 are evenly spaced around the side wall of the crude oil preheater 1 to reduce the dead angle of injection and purge. Preferably, the injection angle of the quenching water gun is 10-30°, and the injection angle of the purge nozzle 5 is 15-45°.

[0021] In addition, the embodiment of the present invention will periodically start the cleaning component to clean the outer wall of the serpentine tube 6. The cleaning scraper 7 moves left and right along the outer wall of the serpentine tube 6 under the action of the telescopic rod 8 to scrape off the carbon black attached to the outer wall of the serpentine tube 6. In order to prevent the cleaning scraper 7 from slipping out of the serpentine tube 6, causing dislocation during the movement, and hitting the serpentine tube 6 to cause damage to the device, the embodiment of the present invention controls the stroke of the telescopic rod 8 within the length of the straight tube section of the serpentine tube 6. During the movement of the cleaning scraper 7, the embodiment of the present invention detects the thrust of the telescopic rod 8 through the pressure sensor 13, and transmits the signal of the pressure sensor 13 to the monitoring device, such as the DCS control device. When the pressure detected by the pressure sensor 13 exceeds the pre-set threshold, it means that the telescopic rod 8 is facing a large resistance at this time, which is most likely caused by the large amount of carbon black attached to the cleaning scraper 7. At this time, in order to avoid damage to the telescopic rod 8 or the cleaning scraper 7, the monitoring device will send a signal to prompt the operator to stop the telescopic rod 8 in time, and arrange maintenance work in time to clean the carbon deposits to ensure that the crude oil preheater 1 can work normally. During the operation of the embodiment of the present invention, the cooling water pipe 10 continuously injects circulating cooling water into the cleaning blade 7 to extend the service life of the cleaning blade 7 in a high temperature environment.

[0022] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A carbon black feedstock oil preheater capable of reducing carbon deposition, characterized in that: The invention comprises a crude oil preheater, a cooling component, a purge component and a cleaning component; the flue gas inlet end of the crude oil preheater is a closed structure, the cross section of which is shaped like a funnel, and a serpentine tube array is arranged in the crude oil preheater; the cooling component is arranged at the flue gas inlet end of the crude oil preheater, and the cooling component comprises at least two quenching water guns for spraying atomized quenching water into the flue gas inlet end of the crude oil preheater; the purge component comprises a purge air valve and at least two purge nozzles, and the purge nozzles are arranged on the inner wall of the crude oil preheater near the serpentine tube array position The cleaning component is disposed at a position connected with the purge air valve through a purge air pipe to spray purge air to the serpentine tube array; the cleaning component includes a cleaning scraper, a telescopic rod, a fixed plate and a cooling water pipe, the cleaning scraper is a hollow structure, disposed in the crude oil preheater, and a through hole for the serpentine tube array to pass through is provided on the cleaning scraper, the fixed plate is disposed outside the crude oil preheater, one end of the telescopic rod is connected to the cleaning scraper, and the other end is connected to the fixed plate, the cooling water pipe is connected to the cleaning scraper, and flowing cooling water is injected into the cleaning scraper.

2. A carbon black feedstock oil preheater capable of reducing carbon deposition according to claim 1, characterized in that: The edge of the through hole is provided with saw teeth.

3. A carbon black feedstock oil preheater capable of reducing carbon deposition according to claim 2, characterized in that: The travel length of the telescopic rod is less than or equal to the length of a single straight pipe section in the serpentine tube array.

4. A carbon black feedstock oil preheater capable of reducing carbon deposition according to claim 3, characterized in that: A pressure sensor is also provided at one end of the telescopic rod connected to the fixed plate, which is used to detect the thrust of the telescopic rod on the cleaning scraper.

5. A carbon black feedstock oil preheater capable of reducing carbon deposition according to claim 4, characterized in that: The pressure sensor signal is connected to the monitoring device. When the pressure sensor signal is greater than a set threshold, the monitoring device sends an alarm signal to stop the telescopic rod from working.

6. A carbon black feedstock oil preheater capable of reducing carbon deposition according to claim 5, characterized in that: The quenching water gun and the purge nozzle are evenly spaced around the side wall of the crude oil preheater. The spray angle of the quenching water gun is 10-30°, and the spray angle of the purge nozzle is 15-45°.

7. A carbon black feedstock oil preheater capable of reducing carbon deposition according to claim 6, characterized in that: The gas sprayed by the purge nozzle is nitrogen or filtered carbon black smoke. When the gas sprayed by the purge nozzle is nitrogen, a heater is also provided on the purge pipe. The nitrogen is heated by the heater and then sprayed into the crude oil preheater by the purge nozzle.

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