Water-free cleaning method for tubular reactor

Abstract

According to the waterless cleaning method for the tubular reactor, special scale in the tubular reactor can be efficiently removed in a waterless cleaning mode of mechanical scrubbing and / or fine sand blasting cleaning, meanwhile, the tubular reactor is prevented from being corroded, and the cleaning effect and the universality of equipment are greatly improved. Quartz sand is filled into the array tubes before and after cleaning, the quartz sand is weighed, and the sand filling rate is calculated, so that quantitative evaluation of the cleaning effect is achieved, and it is ensured that the cleaning quality reaches the standard. And a recovery device is arranged, so that residual substances and / or the catalyst can be synchronously recovered in the cleaning process, resource reutilization and environmental protection are realized, and the comprehensive benefits of the anhydrous cleaning method are further improved.

Description

Technical Field

[0001] The present application relates to the technical field of cleaning of shell and tube reactors, and in particular to a waterless cleaning method for shell and tube reactors. Background Art

[0002] Shell-and-tube reactors are widely used in chemical and pharmaceutical industries due to their compact structure and high heat transfer efficiency. However, after long-term operation, catalysts, reaction by-products, or other dirt will often deposit on the inner tube walls of the reactor, affecting the heat transfer effect and potentially causing safety hazards. Currently, although the commonly used high-pressure water cleaning technology is mature, it is difficult to completely remove certain special scales that react chemically with water; chemical cleaning has the risk of corrosion to equipment materials, especially for equipment with no corrosion margin. Dry ice cleaning is a waterless cleaning method that achieves cleaning through dry ice sublimation, but in actual application, it is easy to produce condensed water due to local cooling, resulting in poor cleaning effect. Summary of the Invention

[0003] The present application aims to solve at least one of the technical problems existing in the prior art. The present application provides a waterless cleaning method for a shell-and-tube reactor, which can efficiently remove special scale in the shell-and-tube reactor through a waterless cleaning method of mechanical scrubbing and / or fine sandblasting, thereby achieving better cleaning effect.

[0004] The waterless cleaning method for a shell-and-tube reactor according to an embodiment of the present application comprises the following steps:

[0005] In the pretreatment step, before cleaning, fill the tubes of the shell-and-tube reactor with quartz sand, and weigh the required quartz sand and record it as m a , transporting the cleaning equipment into the shell and tube reactor;

[0006] Cleaning steps;

[0007] In the acceptance step, after cleaning, the quartz sand is filled into the tubes of the tube reactor, and the required quartz sand is weighed and recorded as m b , calculate the sand filling rate and judge whether the cleaning meets the standards according to the value of the sand filling rate;

[0008] The sand filling rate is calculated by the following formula:

[0009]

[0010] Among them, S is the sand filling rate, m a The mass of quartz sand required to fill the tubes before cleaning, m b The mass of quartz sand required to fill the tubes with cleaned quartz sand.

[0011] According to some embodiments of the present application, the cleaning step includes a mechanical brushing step and / or a sandblasting cleaning step.

[0012] According to some embodiments of the present application, the mechanical scrubbing step includes the following steps:

[0013] Step a1. Connect the rotating flexible shaft to the cleaning device and install a brush head that meets the brush interference ratio conditions on the rotating flexible shaft;

[0014] Step b1. The brush head is placed in the tube array;

[0015] Step c1. starting the cleaning device;

[0016] Step d1. Control the brush head to reciprocate in the tube array at a preset rotation speed and movement speed to achieve brushing of a single tube array;

[0017] The step d1 is repeated until all the tubes are cleaned.

[0018] According to some embodiments of the present application, the sandblasting cleaning step includes the following steps:

[0019] Step a2. Connect one end of the sandblasting tube to the cleaning equipment, and the other end of the sandblasting tube to the nozzle;

[0020] Step b2. The nozzle is directed toward the tube;

[0021] Step c2. Filling sand;

[0022] Step d2. controlling the nozzle to rotate and axially blast the tubes in a preset manner;

[0023] The step d2 is repeated until all the tubes are cleaned.

[0024] According to some embodiments of the present application, the step further includes detecting the wear of the bristles of the brush head, and determining whether to replace the brush head according to the wear of the bristles;

[0025] The steps d1 and e1 are repeated until all the tubes are cleaned.

[0026] According to some embodiments of the present application, the cleaning equipment is a scrubber, the input air pressure of the scrubber is 0.7-0.8 MPa, the interference fit ratio of the brush head is 6%-10%, and the rotation speed of the rotating flexible shaft is 400-600 rpm.

[0027] According to some embodiments of the present application, the cleaning equipment is configured as a sandblasting machine, the output air pressure of the sandblasting machine is 0.5-0.8 MPa, the sand material is quartz sand, and the particle size of the quartz sand is 1-1.5 mm.

[0028] According to some embodiments of the present application, the pretreatment step includes installing a recovery device at the bottom of the shell-and-tube reactor; and a recovery step is also included between the cleaning step and the acceptance step, and recovery is performed through the recovery device.

[0029] According to some embodiments of the present application, the recovery device includes a dust collecting device arranged at the bottom of the shell and tube reactor and a dust extraction device connected to the dust collecting device; in the mechanical scrubbing step, the dust extraction device is kept turned on to collect the residual matter generated during the mechanical scrubbing process into the dust collecting device; the dust collecting device includes a first filter assembly, which is used to filter the residual matter removed during the scrubbing process and collect recyclable matter; in the mechanical scrubbing step, the first filter assembly is replaced to maintain the filtering performance; in the recovery step, the first filter assembly is removed to recover the recyclable matter.

[0030] According to some embodiments of the present application, the recovery device includes a sand collecting device arranged at the bottom of the shell and tube reactor and a sand pumping device connected to the sand collecting device; in the sand blasting cleaning step, the residual material generated during the sand blasting cleaning process is collected into the sand collecting device by keeping the sand pumping device turned on; the sand collecting device includes a second filter assembly, which is used to filter the residual material removed during the scrubbing process and collect recyclable materials; in the sand blasting cleaning step, the second filter assembly is replaced to maintain the filtering performance; in the recovery step, the second filter assembly is removed to recover the recyclable materials.

[0031] The waterless cleaning method for a shell-and-tube reactor according to an embodiment of the present application has at least the following beneficial effects:

[0032] The waterless cleaning method for shell and tube reactors of the present application can efficiently remove special scale in shell and tube reactors through the waterless cleaning method of mechanical scrubbing and / or fine sandblasting, while avoiding corrosion of the reactor, greatly improving the cleaning effect and the versatility of the equipment. By filling the shell and tube with quartz sand and weighing it before and after cleaning, the sand filling rate is calculated, thereby achieving a quantitative evaluation of the cleaning effect and ensuring that the cleaning quality meets the standards. The provision of a recovery device can simultaneously recover residual substances and / or catalysts during the cleaning process, realizing resource recycling and environmental protection, and further enhancing the comprehensive benefits of the waterless cleaning method of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present application is further described below with reference to the accompanying drawings and embodiments, wherein:

[0034] Figure 1 This is a schematic diagram of a mechanically scrubbed tubular reactor according to one embodiment of the present application;

[0035] Figure 2 This is a schematic diagram of a shell-and-tube reactor for sandblasting cleaning according to one embodiment of the present application;

[0036] Figure 3 This is a flow chart of mechanical scrubbing according to an embodiment of the present application;

[0037] Figure 4 This is a sandblasting cleaning flow chart of an embodiment of the present application. DETAILED DESCRIPTION

[0038] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0039] In the description of this application, it should be understood that if the terms "center", "middle", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this application, unless otherwise specified, "multiple" means two or more.

[0040] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0041] Refer to the following Figures 1 to 4 The waterless cleaning method of the shell and tube reactor in the examples of the present application is described.

[0042] according to Figures 1 to 4 As shown, the waterless cleaning method of a shell and tube reactor in one embodiment of the present application includes the following steps:

[0043] S1. Pretreatment step: before cleaning, fill the tubes of the shell-and-tube reactor with quartz sand with a particle size of 50 to 100 μm, and weigh the required quartz sand and record it as m a After recording is completed, the quartz sand is removed from the tubes; the cleaning equipment is transported into the tube reactor;

[0044] S2. Cleaning step: cleaning the tubes;

[0045] S3. Acceptance step: After cleaning, fill the tubes of the shell-and-tube reactor with quartz sand with a particle size of 50 to 100 μm, and weigh the required quartz sand and record it as m b , calculate the sand filling rate and judge whether the cleaning meets the standards based on the value of the sand filling rate;

[0046] The sand filling rate is calculated using the following formula:

[0047]

[0048] Among them, s is the sand filling rate, m a The mass of quartz sand required to fill the tubes before cleaning, m b The mass of quartz sand required to fill the tubes with cleaned quartz sand.

[0049] After a cleaning cycle, the sand filling rate of the tubular reactor was tested to be 15% or higher, indicating good cleaning results. The waterless cleaning method for tubular reactors in this application calculates the sand filling rate by filling the tubular reactors with quartz sand of the same specification before and after cleaning, weighing the sand, and then calculating the sand filling rate. This provides a visual, data-based cleaning effect evaluation method, improving the objectivity of cleaning effect assessment.

[0050] according to Figures 1 to 4 As shown, in one embodiment of the present application, the cleaning step includes a mechanical scrubbing step and / or a fine sandblasting cleaning step. The mechanical scrubbing step involves high-speed rotation to achieve high-frequency friction with the inner wall of the tubes of the shell-and-tube reactor, utilizing the frictional force to remove residual matter from the inner wall of the tubes. The fine sandblasting cleaning step involves a cleaning device converting fine sand and high-pressure gas into a high-speed sand jet through a fine-aperture jet device, thereby impacting the inner wall of the tubes to clean residual matter.

[0051] The mechanical brushing steps and fine sandblasting cleaning steps are as follows:

[0052] according to Figure 1 and Figure 3As shown, in one embodiment of the present application, the mechanical scrubbing step includes the following steps:

[0053] Step a1. Connect the rotating flexible shaft to the cleaning device and install a brush head that meets the brush interference ratio conditions on the rotating flexible shaft;

[0054] Step b1. Place the brush head in the tube array;

[0055] Step c1. Start the cleaning equipment;

[0056] Step d1. Control the brush head to reciprocate in the tube array at a preset rotation speed and movement speed to achieve brushing of a single tube array;

[0057] Repeat step d1 until all tubes are cleaned.

[0058] In some embodiments, step d1 includes the more specific steps of:

[0059] Step d1.1. Control the brush head to maintain a preset rotation speed and movement speed, moving from the top of the tube along the inner wall to the bottom to perform rotary friction scrubbing, thereby removing residual matter on the inner wall of the tube;

[0060] Step d1.2. The brush head scrubs to the bottom of the tube array, then rotates in the opposite direction, moves back to the top of the tube array and leaves the tube array, completing the scrubbing of the tube array;

[0061] By switching between the two rotation directions, residual substances can be better removed to achieve better cleaning effects.

[0062] In some embodiments, the flexible rotary shaft is configured as a metal flexible rotary shaft; specifically, a steel wire flexible rotary shaft.

[0063] In some embodiments, the brush head is provided as a brass brush head.

[0064] In some embodiments, the brush head moves in the tube array at a speed of 40 mm / s.

[0065] according to Figure 2 and Figure 4 As shown, in one embodiment of the present application, the sandblasting cleaning step includes the following steps:

[0066] Step a2. Connect one end of the sandblasting tube to the cleaning equipment and the other end of the sandblasting tube to the nozzle;

[0067] Step b2. Direct the nozzle toward the tubes;

[0068] Step c2. Filling sand;

[0069] Step d2. Control the nozzle to rotate and axially blast the tubes in a preset manner;

[0070] Repeat step d2 until all tubes are cleaned.

[0071] In some embodiments, a more specific step d2 is to control the nozzle to be inserted into the tube and sandblast for 30 seconds. For the first 20 seconds, the nozzle is tilted at an angle of ≤5°, and the nozzle rotates along the tube wall to perform sandblasting. For the next 10 seconds, the nozzle is vertically positioned, and the nozzle is directed vertically toward the tube to perform sandblasting, completing the cleaning of the tube. By first achieving the cutting and scrubbing effect of the sand particles on the tube wall at an inclined angle, the ability to remove stubborn scale is enhanced. The full rotation achieves comprehensive coverage of the inner wall of the tube. Then, vertical jetting is used to supplement the impact cleaning to further remove residual matter, effectively improving the thoroughness and uniformity of the cleaning.

[0072] according to Figure 1 and Figure 3 As shown, in one embodiment of the present application, the step e1 is further included. Detecting the wear of the bristles of the brush head, and determining whether to replace the brush head with a new one according to the wear of the bristles;

[0073] Repeat steps d1 and e1 until all tubes are cleaned.

[0074] The judgment of bristle wear specifically includes:

[0075] When the bristles of the brush head are detected to be damaged, a new cleaning brush head needs to be replaced in time;

[0076] When it is detected that the brush head has a large amount of cleaning residue in the tube (i.e. the brush interference ratio is too large), it is necessary to replace the cleaning brush head in time;

[0077] In the tube array, the brush head needs to be replaced with a new one every time it moves and cleans 30 meters cumulatively;

[0078] according to Figure 1 and Figure 3 As shown, in one embodiment of the present application, in the mechanical brushing step, the cleaning equipment is specifically a brushing machine, the input air pressure of the brushing machine is 0.7~0.8MPa, the interference ratio of the brush head is 6%~10%, and the rotation speed of the rotating soft shaft is 400~600rpm.

[0079] The brush interference ratio is calculated using the following formula:

[0080]

[0081] Where η is the brush interference ratio, Δ is the interference between the outer diameter of the brush bristles and the inner diameter of the tube, is the inner diameter of the tube.

[0082] according to Figure 2 and Figure 4As shown, in one embodiment of the present application, in the fine sandblasting cleaning step, the cleaning equipment is specifically a sandblasting machine, the nozzle size of the sandblasting machine is Φ10mm*2cm, the output air pressure of the sandblasting machine is 0.5-0.8MPa, the sand material is quartz sand, the particle size of the quartz sand is 1-1.5mm, the sand delivery valve of the sandblasting machine is opened to more than 2 / 3, and the sandblasting air volume of the sandblasting machine is 6m 3 / min. By using quartz sand with a particle size of 1 to 1.5 mm as the sandblasting medium, optimizing sandblasting parameters, and researching fine sandblasting techniques, the efficiency of removing residual material from the inner walls of the tubes can be significantly improved. This ensures uniform distribution of impact force during the cleaning process, effectively covering different locations of the tubes, and thus ensuring consistent and thorough cleaning. Furthermore, controlling the particle size within the range of 1 to 1.5 mm can reduce mechanical wear on the inner walls of the tubes without reducing cleaning efficiency, avoiding scratches and localized stress concentration, thereby extending the service life of the shell-and-tube reactor and the safety of the cleaning process.

[0083] according to Figures 1 to 4 As shown, in one embodiment of the present application, the pretreatment step includes installing a recovery device at the bottom of the tubular reactor; and a recovery step is also included between the cleaning step and the acceptance step, and the recovery is performed through the recovery device. That is:

[0084] S1. Pretreatment step: before cleaning, fill the tubes of the shell-and-tube reactor with quartz sand with a particle size of 50 to 100 μm, and weigh the required quartz sand and record it as m a After recording is completed, the quartz sand is removed from the tubes; the cleaning equipment is transported into the tube reactor; and a recovery device is installed at the bottom of the tube reactor;

[0085] S2. Cleaning step: cleaning the tubes;

[0086] S3. Recovery step, recovery by a recovery device;

[0087] S4. Acceptance step: After cleaning, fill the tubes of the shell-and-tube reactor with quartz sand with a particle size of 50 to 100 μm, and weigh the required quartz sand and record it as m b , calculate the sand filling rate and judge whether the cleaning meets the standards based on the value of the sand filling rate;

[0088] In some embodiments, the pretreatment step includes connecting the cleaning equipment and the gas source through an air pipe; in the cleaning step, the gas source sprays high-pressure gas into the tubes, and the residual substances that have fallen off the inner walls of the tubes are blown to the recovery device at the bottom of the tube reactor along with the high-pressure gas, and the recovery device filters, separates and recovers the residual substances.

[0089] In some embodiments, the waterless cleaning method of the shell-and-tube reactor of the present application is applicable to the following scenarios: (1) the upper head of the shell-and-tube reactor is removable or the upper head cannot be removed but there are space conditions for cleaning personnel to enter the reactor to carry out cleaning operations; (2) the bottom of the shell-and-tube reactor has installation conditions for installing a recovery device.

[0090] according to Figure 1 and Figure 3 As shown, in one embodiment of the present application, in the mechanical scrubbing cleaning, the recovery device specifically includes a dust collecting device and a dust extraction device. The dust collecting device is used to filter and collect recyclable substances (such as catalysts) in the residual substances, and the dust extraction device is used to form a negative pressure environment in the tubes to suck out the residual substances in the tubes; in the pretreatment step, the dust collecting device is installed at the bottom of the tube-in-tube reactor and the dust extraction device is connected to the dust collecting device; in the mechanical scrubbing step, the residual substances generated during the mechanical scrubbing process are collected into the dust collecting device for filtration by keeping the dust extraction device turned on.

[0091] The dust collecting device includes a first filter component, which is used to filter the residual substances removed during the mechanical brushing process and collect the catalyst. The remaining impurities and dirt are sucked into the dust extraction equipment through the first filter component; in the mechanical brushing step, it includes replacing the first filter component to maintain the filtering performance; in the recovery step, it includes removing the first filter component to recover the catalyst.

[0092] according to Figure 2 and Figure 4 As shown, in one embodiment of the present application, in fine sandblasting cleaning, the recovery device specifically includes a sand collecting device and a sand pumping device. The sand collecting device is used to filter and collect recyclable substances (such as catalysts) in the residual substances, and the sand pumping device is used to form a negative pressure environment in the tubes to suck out the residual substances in the tubes; in the pretreatment step, the sand collecting device is installed at the bottom of the tube-in-tube reactor and the sand collecting device is connected to the sand pumping device; in the sandblasting cleaning step, the residual substances generated during the sandblasting cleaning process are collected into the sand collecting device for filtration by keeping the sand pumping device turned on.

[0093] The sand collecting device includes a second filter component, which is used to filter the residual substances removed during the sandblasting cleaning process and collect the catalyst. The remaining impurities, dirt and sand are sucked into the sand pumping equipment through the second filter component; in the sandblasting cleaning step, it includes replacing the second filter component to maintain the filtering performance; in the recovery step, it includes removing the second filter component to recover the catalyst.

[0094] In some embodiments, the sand pumping device includes a third filter component, which is used to filter out impurities and dirt in the sand material to achieve sand recycling.

[0095] according to Figures 1 to 4 As shown, the following is a specific method for anhydrous cleaning of a shell and tube reactor:

[0096] Mechanical scrubbing to clean shell and tube reactors:

[0097] S1. Pretreatment step: before cleaning, fill the tubes of the shell-and-tube reactor with quartz sand with a particle size of 50 to 100 μm, and weigh the required quartz sand and record it as m a After recording, remove the quartz sand from the tubes; transport the scrubber to the tube reactor, connect the scrubber to the gas source through the gas pipe, and arrange the gas pipe position reasonably; install a dust collection device at the bottom of the tube reactor, and connect the dust extraction equipment to the dust collection device;

[0098] S2. Mechanical scrubbing step, scrubbing the tubes, including:

[0099] Step a1. Connect the rotating flexible shaft to the brushing machine and install a brush head that meets the brush interference ratio conditions on the rotating flexible shaft;

[0100] Step b1. Remove the tube caps, place the brush head in the tubes and turn on the dust extraction device;

[0101] Step c1. Start the scrubbing machine and start scrubbing;

[0102] Step d1.1. Straighten the rotating flexible shaft and place it into the tube array. Then, control the brush head to maintain a preset rotation speed and movement speed, moving from the top of the tube array along the inner wall to the bottom to perform rotary friction scrubbing to remove residual matter on the inner wall of the tube array.

[0103] Step d1.2. Scrub the brush to the bottom of the tube array, straighten the rotating flexible shaft, pull out the rotating flexible shaft, and at the same time, rotate the brush head in the opposite direction to scrub. Move the brush head back to the top of the tube array and leave the tube array to complete the scrubbing of the tube array;

[0104] Step e1. Detecting the wear of the bristles of the brush head and determining whether to replace the brush head with a new one based on the wear of the bristles;

[0105] Repeat steps d1 and e1 until all tubes are cleaned.

[0106] During mechanical scrubbing, the dust collecting device is cleaned regularly, the first filter assembly is replaced to maintain the filtering performance, and the catalyst is recovered and bagged.

[0107] S3 recovery step, remove the first filter assembly to recover the catalyst, the catalyst recovery play bag;

[0108] S4. Acceptance step: After cleaning, fill the tubes of the shell-and-tube reactor with quartz sand with a particle size of 50 to 100 μm, and weigh the required quartz sand and record it as m b,pass Calculate the sand filling rate and judge whether the cleaning meets the standards based on the value of the sand filling rate. If the sand filling rate reaches 1.5% or above, the cleaning meets the standards.

[0109] Fine sandblasting cleaning of tubular reactors:

[0110] S1. Pretreatment step: before cleaning, fill the tubes of the shell-and-tube reactor with quartz sand with a particle size of 50 to 100 μm, and weigh the required quartz sand and record it as m a After recording, remove the quartz sand from the tubes; transport the sandblasting machine into the tube reactor, connect the sandblasting machine and the gas source through the air pipe, and arrange the air pipe position reasonably; install a sand collecting device at the bottom of the tube reactor, and connect the sand pumping equipment to the sand collecting device;

[0111] S2. Sandblasting cleaning step, cleaning the tubes, including:

[0112] Step a2. Connect one end of the sandblasting tube to the sandblasting machine and the other end of the sandblasting tube to the nozzle;

[0113] Step b2. Remove the tube cap and point the nozzle toward the tube;

[0114] Step c2. Load the sand and start the sand pumping device;

[0115] Step d2. Start the sandblasting machine and control the nozzle to be inserted into the tube and sandblast for 30 seconds. For the first 20 seconds, tilt the nozzle at an angle of ≤5° and rotate the nozzle along the tube wall for one circle to sandblast. For the last 10 seconds, vertically point the nozzle toward the tube and sandblast to complete the cleaning of the tube.

[0116] Repeat step d2 until all tubes are cleaned.

[0117] During the sandblasting cleaning process, the sand collecting device is cleaned regularly, the second filter assembly is replaced to maintain the filtering performance, and the catalyst is recovered and bagged.

[0118] S3 recovery step, remove the second filter assembly to recover the catalyst, the catalyst recovery play bag;

[0119] S4. Acceptance step: After cleaning, fill the tubes of the shell-and-tube reactor with quartz sand with a particle size of 50 to 100 μm, and weigh the required quartz sand and record it as m b ,pass Calculate the sand filling rate and judge whether the cleaning meets the standards based on the value of the sand filling rate. If the sand filling rate reaches 1.5% or above, the cleaning meets the standards.

[0120] The waterless cleaning method for a shell-and-tube reactor provided in the present application effectively removes catalyst residues and special scales attached to the inner wall of the shell and tube reactor through mechanical brushing and / or fine sandblasting cleaning without using any water or chemical cleaning agents. It is particularly suitable for special scales that are difficult to handle by traditional high-pressure water washing, dry ice cleaning or chemical cleaning. It significantly improves the cleaning efficiency and scope of application, avoids problems such as equipment corrosion and residual chemical risks caused by water or chemicals, and fundamentally ensures the safety and service life of the shell-and-tube reactor.

[0121] By filling the tubes with quartz sand of the same particle size before and after cleaning and weighing them, and combining it with the "sand filling rate" calculation formula, a quantifiable, traceable, and easy-to-operate cleaning effect judgment mechanism was established. Compared with the traditional method that relies on visual inspection or experience, the evaluation of the cleaning effect is more objective and accurate.

[0122] A recovery device is set up during the cleaning process to simultaneously collect the removed residual substances (such as catalysts, scale and sandblasting materials), and effectively separate and recycle useful substances through filtering components, thereby realizing resource recycling, reducing material loss, significantly reducing cleaning costs and reducing environmental pollution, which is in line with the green production concept.

[0123] In the description of this specification, if the reference terms "one embodiment," "some examples," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples" appear, it means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples.

[0124] The above describes the implementation methods of the present application in detail in conjunction with the accompanying drawings, but the present application is not limited to the above implementation methods. Various changes can be made within the scope of knowledge possessed by ordinary technicians in the technical field without departing from the purpose of the present application.

Claims

1. A method for anhydrous cleaning of a tubular reactor, characterized in that: The following steps are included In the pretreatment step, before cleaning, fill the tubes of the shell-and-tube reactor with quartz sand, and weigh the required quartz sand and record it as m a , transporting the cleaning equipment into the shell and tube reactor; Cleaning steps; In the acceptance step, after cleaning, the quartz sand is filled into the tubes of the tube reactor, and the required quartz sand is weighed and recorded as m b , calculate the sand filling rate and judge whether the cleaning meets the standards according to the value of the sand filling rate; The sand filling rate is calculated by the following formula: Among them, S is the sand filling rate, m a The mass of quartz sand required to fill the tubes before cleaning, m b The mass of quartz sand required to fill the tubes with cleaned quartz sand.

2. The waterless cleaning method for a shell and tube reactor according to claim 1, wherein: The cleaning step includes a mechanical brushing step and / or a sandblasting cleaning step.

3. The waterless cleaning method for a shell and tube reactor according to claim 2, wherein: The mechanical scrubbing step comprises the following steps: Step a1. Connect the rotating flexible shaft to the cleaning device and install a brush head that meets the brush interference ratio conditions on the rotating flexible shaft; Step b1. The brush head is placed in the tube array; Step c1. starting the cleaning device; Step d1. Control the brush head to reciprocate in the tube array at a preset rotation speed and movement speed to achieve brushing of a single tube array; The step d1 is repeated until all the tubes are cleaned.

4. The waterless cleaning method for a shell and tube reactor according to claim 2, wherein: The sandblasting cleaning step comprises the following steps: Step a2. Connect one end of the sandblasting tube to the cleaning equipment, and the other end of the sandblasting tube to the nozzle; Step b2. The nozzle is directed toward the tube; Step c2. Filling sand; Step d2. controlling the nozzle to rotate and axially blast the tubes in a preset manner; The step d2 is repeated until all the tubes are cleaned.

5. The waterless cleaning method for a shell and tube reactor according to claim 3, wherein: The method further comprises the steps of detecting the wear of the bristles of the brush head and determining whether to replace the brush head according to the wear of the bristles; The steps d1 and e1 are repeated until all the tubes are cleaned.

6. The waterless cleaning method for a shell and tube reactor according to claim 3, characterized in that: The cleaning device is a scrubber, the input air pressure of the scrubber is 0.7-0.8 MPa, the interference fit ratio of the brush head is 6%-10%, and the rotation speed of the rotating flexible shaft is 400-600 rpm.

7. The waterless cleaning method for a shell-and-tube reactor according to claim 4, wherein: The cleaning equipment is configured as a sandblasting machine, the output air pressure of the sandblasting machine is 0.5-0.8 MPa, the sand material is quartz sand, and the particle size of the quartz sand is 1-1.5 mm.

8. The waterless cleaning method for a shell and tube reactor according to claim 3 or 4, characterized in that: The pretreatment step includes installing a recovery device at the bottom of the shell-and-tube reactor; and a recovery step is also included between the cleaning step and the acceptance step, and recovery is performed through the recovery device.

9. The waterless cleaning method for a shell-and-tube reactor according to claim 8, characterized in that: The recovery device includes a dust collecting device arranged at the bottom of the tubular reactor and a dust extraction device connected to the dust collecting device; In the mechanical scrubbing step, the residual material generated during the mechanical scrubbing process is collected into the dust collecting device by keeping the dust extraction equipment turned on; the dust collecting device includes a first filter component, which is used to filter the residual material removed during the scrubbing process and collect recyclable materials; in the mechanical scrubbing step, the first filter component is replaced to maintain the filtering performance; in the recovery step, the first filter component is removed to recover the recyclable materials.

10. The waterless cleaning method for a shell-and-tube reactor according to claim 8, characterized in that: The recovery device includes a sand collecting device arranged at the bottom of the shell and tube reactor and a sand pumping device connected to the sand collecting device; in the sand blasting cleaning step, the residual material generated during the sand blasting cleaning process is collected into the sand collecting device by keeping the sand pumping device turned on; the sand collecting device includes a second filter assembly, which is used to filter the residual material removed during the scrubbing process and collect recyclable materials; in the sand blasting cleaning step, the second filter assembly is replaced to maintain the filtering performance; in the recovery step, the second filter assembly is removed to recover the recyclable materials.

Images