Flushing and drying treatment system for heat transfer element package of movable air pre-heater

Abstract

The invention belongs to the technical field of boiler equipment cleaning, and discloses a movable air pre-heater heat transfer element package flushing and drying treatment system which is used for conducting off-line cleaning and drying on a seriously-blocked air pre-heater heat transfer element package. Comprising a moving device with a cavity, the moving device is internally provided with an alkali liquor soaking box used for pretreating the element bag, a flushing box used for flushing the element bag, a recycling box used for recycling flushing water, an alkali removing box used for removing residual alkali water in the element bag and a drying box, and the element bag sequentially passes through all stations to be flushed and dried. According to the device, the heat transfer element bag does not need to be disassembled, the system integration degree is high, the occupied area is small, the flexibility is good, and labor is little. The heat transfer element sheet is not lost in the cleaning process, and the surface of the heat transfer element sheet is not damaged. The device has the advantages of being high in cleaning speed, good in cleaning effect and low in cleaning cost, and can also be used for meeting the cleaning requirements of equipment such as a boiler SCR denitration catalyst module by properly adjusting parameters.

Description

Technical Field

[0001] The present invention belongs to the technical field of boiler equipment cleaning, and relates to a mobile air preheater heat transfer element package flushing and drying treatment system, which is used to treat air preheater heat transfer element packages that are severely clogged and traditionally require manual unpacking and flushing or high-pressure water flushing. Background Art

[0002] The rotary air preheater is a key component of large boiler systems. It can recover more than 15% of the fuel heat, increase combustion air temperature, accelerate combustion, and improve fuel burnout. One of its key control features is to ensure that the airflow resistance of the flue gas and air is within the allowable range, thereby ensuring low energy consumption and safety of the boiler's induced draft fan and forced draft fan. The core equipment of the air preheater is the hundreds of heat transfer element packs installed in the rotor. The element pack structure is shown in the attached figure. Figure 1 Each package consists of one to two hundred laminated heat transfer elements mounted in a metal frame. The elements are 0.5-1.0mm thick and feature several millimeters deep heat transfer enhancement patterns. Elements in severely corroded areas are coated with a protective enamel layer. The average spacing between the elements is 10-15mm. The element packages are typically trapezoidal in cross-section and 0.3-1.5m high. Each package weighs 0.1-1.2t. Due to the narrow airflow channels, large specific surface area, and low flue gas temperature within the air preheater, some components in the flue gas, such as sulfuric acid vapor and ammonium bisulfate vapor, condense into liquid on the surface of the heat transfer element plates, adsorbing ash in the flue gas to form surface dust. Over time, dust accumulation that is not removed will form a stubborn scale layer composed mainly of calcium sulfate, calcium carbonate, and fly ash, which becomes more difficult to clean. This reduces the heat exchange capacity of the air preheater. As the operating time increases, the airflow channels within the heat transfer element package become partially blocked, the flue gas and air resistance increase exponentially, the fan current increases significantly, and the fan reserve is exhausted, causing problems such as fan surge, which endangers the safe operation of the boiler.

[0003] Traditionally, when steam soot blowing in the air preheater is ineffective, the following methods are used to clean the dust and dirt inside the component package:

[0004] Method 1: Use online low-flow high-pressure water flushing. This method is generally unable to completely clean the dust accumulated in the component, and the effect decreases with the increase in the number of uses.

[0005] Method 2: During the shutdown phase, high-flow, low-pressure water is used for flushing, and the water consumption is often hundreds of tons per hour. Due to the low water pressure, the contact time between the scale layer and water is short, and the scale is not softened, making it difficult to clean thoroughly. Moreover, after cleaning, the surface is often not dried, and it will soon become clogged again shortly after being put back into operation.

[0006] Method 3: Manual high-pressure water flushing during shutdown or orbital ultra-high-pressure water cleaning. Due to the high water pressure of 30-70MPa, local heat transfer components are often torn and damaged. After flushing and commissioning, there are disadvantages such as component fragments blocking the component package air flow channel, blocking the air preheater rotor, and debris flying into the electrostatic precipitator causing accidents.

[0007] Method 4: Lift out the severely clogged component package, cool it with dry ice, freeze and separate the scale layer and component pieces, and then remove the dust by vibration. This method is expensive to clean, takes a long time, has a poor construction environment, and it is difficult to achieve the purpose of thorough cleaning.

[0008] Method 5: Manual unpacking is used to remove the component pieces and then manually clean the surface. This method consumes a lot of manpower and is slow to clean. In addition, when restoring the component package, the component pieces are difficult to completely reinstall, resulting in loss of heat exchange area and deformation of the component package size, making it difficult to reinstall the component package. Summary of the Invention

[0009] In order to solve the above problems, the present invention provides a mobile air preheater heat transfer element package flushing and drying treatment system for treating seriously clogged air preheater heat transfer element packages.

[0010] A mobile air preheater heat transfer element package flushing and drying treatment system includes a mobile device with a cavity. The mobile device is equipped with an alkali solution soaking tank for pre-treating the element package, a flushing tank for flushing the element package, a recovery tank for recovering the flushing water, a de-alkali tank for removing alkaline water residue in the element package, and a drying tank. The element package passes through each station in sequence to achieve flushing and drying.

[0011] This invention allows for convenient and centralized treatment of severely clogged air preheater heat transfer element packages, eliminating the need for disassembly, loss of heat transfer element sheets, and damage to the elements. The mobile device used to house the equipment is a flatbed carriage designed for highway transport and capable of being towed by a standard truck.

[0012] According to the present invention, further, the moving device is provided with a lifting device for moving the heat transfer element package to be cleaned.

[0013] According to the present invention, further, the trailer box includes a box-shaped vehicle body, the interior of which is provided with a bottom plate, a detachable up and down step ladder, a water inlet main pipe connected to an external water source at one end, a sewage main pipe connected to an external sewage area at one end, and an electric control box; wheels are installed on the outer bottom of the box-shaped vehicle body.

[0014] According to the present invention, further, the alkali solution soaking tank includes a soaking tank body, inside of which are provided with stirring blades, a soaking tank load-bearing grid, a soaking tank water inlet pipe, a pH meter, a thermometer, and a soaking tank sewage pipe.

[0015] According to the present invention, further, the flushing box includes a flushing box body, inside which are arranged a flushing box load-bearing grille, a flushing box water inlet pipe, a cleaning pipe transmission structure, a low-pressure cleaning structure connected to the cleaning pipe transmission structure, a high-pressure cleaning structure and a flushing pipe discharge pipe.

[0016] According to the present invention, further, the recovery box includes a recovery box body, inside of which a partition, a recovery box water inlet pump, a recovery box water outlet pump, and a recovery box sewage pipe are arranged.

[0017] According to the present invention, further, the dealkali tank includes a dealkali tank body, inside of which are arranged a dealkali tank load-bearing grid, a water spray pipe driving structure, a water spray pipe connected to the water spray pipe driving structure, a dealkali tank water inlet pipe, a dealkali tank drainage pump, and a dealkali tank sewage pipe.

[0018] According to the present invention, further, the drying box includes a drying box body, inside of which a drying box load-bearing grid, a blowing structure, an electric heating pipe group and a drying box sewage pipe are arranged.

[0019] According to the present invention, further, the lifting device includes a beam arranged at an upper position inside the mobile device, a retractable structure is provided at the bottom of the beam, the bottom of the retractable structure is fixed, and is used to adjust the height of the beam, and a track beam pointing to the inside of the mobile device is also provided on the beam, and the track beam slides in the horizontal direction of the beam to drive the component package to move between various workstations.

[0020] According to the present invention, further, electric hoists are provided at both ends of the crossbeam, connected to hooks, for driving a trolley carrying the component package to move to the rail beam. The trolley is used to transport the heat transfer component package on the ground, and generally several trolleys are provided.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention is composed of a trailer box, a lifting device, a transfer trolley, an alkali solution soaking box, a flushing box, a recovery box, an alkali removal box and a drying box, etc., which can conveniently and centrally handle the air preheater heat transfer element package that is severely clogged. There is no need to disassemble the heat transfer element package, and the cleaning process will not cause the heat transfer element pieces to be lost or damaged.

[0022] The device of the present invention has the advantages of fast cleaning speed, good cleaning effect and low cleaning cost. After appropriate adjustment of parameters, it can also be used to meet the cleaning needs of boiler SCR denitration catalyst modules. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the heat transfer element package structure.

[0024] Figure 2 It is a side structural schematic diagram of the system of the present invention.

[0025] Figure 3 Schematic diagram of the top view of the system of the present invention. DETAILED DESCRIPTION

[0026] The present invention will be described in detail below with reference to the following embodiments. Figure 2 and Figure 3 shown.

[0027] Example

[0028] After the equipment is loaded into trailer 1 and transported to the site, it is placed on the ground near the air preheater and wheels 1.1 are temporarily secured. The main water inlet pipe 1.5 is connected to the power plant's local low-pressure water source (process water), and the main sewage pipe 1.6 is connected to the on-site sewage ditch. After connecting the power supply, the electrical equipment such as the pump and fan are debugged.

[0029] First, fill the alkali solution soaking tank 4 with water to a level at least 50 mm above the height of the highest component package, then start the electric propeller 4.2. Add alkali powder to the water, preferably a weak base such as sodium carbonate, sodium bicarbonate, or some organic base, to control the solution's initial pH to around 12. The water temperature can be higher if conditions permit, but should not be less than 5°C. If the pH drops below 10 during the process, add a small amount of alkali powder. Protect your eyes and exposed skin during operation.

[0030] After hoisting the component package from the air preheater, place it on the ground. Use the power plant's compressed air duct to blow away any dust on the package's surface. Then, use a transfer cart (3) to move it below the cantilever end of the track beam (2,4) of the present invention's system and hoist it into the alkali solution soaking tank (4). The entire component package must be completely submerged in the liquid. Depending on the space available in the alkali solution soaking tank (4), multiple packages can be hoisted in at once. The minimum soaking time for the component package depends on its blockage and size, but is generally not less than 20 minutes.

[0031] After soaking, move the component package into the flushing tank 5, start the recycling tank outlet pump 6.4 (using recycled water, the outlet water pressure should not be less than 0.5MPa), start the recycling tank inlet pump 6.3 and the cleaning pipe chain transmission device 5.5, and rinse the component package. Manually monitor the cleaning effect, generally using a strong flashlight to observe the internal cleaning situation. For serious fouling, start the high-pressure water pump 5.7 (output water pressure range 20-50MPa, water source is external process water), and use the high-pressure cleaning pipe 5.8 to strengthen the flushing of the component package. For local points with stubborn fouling, use the high-pressure manual cleaning spray gun 5.9 for local fixed-point cleaning. The nozzle of the high-pressure cleaning pipe 5.8 should be made of wear-resistant materials, such as wear-resistant stainless steel, silicon carbide, etc.

[0032] After confirming complete cleaning, the component package is moved into the de-alkali tank 7. The valve on the de-alkali tank's water inlet line 7.6, the water spray pipe drive chain assembly 7.4, and the drive assembly 7.5 that controls its activation are opened. Clean water is then sprayed onto the component package to remove surface contaminated water stains and prevent contaminated water from corroding the original components. The de-alkali tank's drain pump 7.7 is activated to direct the used cleaning water into the recovery water tank 6, reducing overall water consumption. Preferably, the water spray pipe drive chain assembly 7.4 is positioned near the inner top wall of the de-alkali tank body 7.1. This allows the component package to be cleaned as it travels, ensuring a wide cleaning range and ensuring efficient cleaning of the component package.

[0033] If the component package is not in a hurry to be used after de-alkali treatment, it can be naturally air-dried or hoisted back to the air preheater and blown dry with a fan. If the weather is humid or the unit needs to be urgently restored to operation within a short period of time, the component package can be moved into the drying oven 8, the electric heating tube assembly 8.6 is activated, the temperature inside the oven is raised to no less than 60°C, the blower 8.4 is turned on, the drying oven lid 8.3 is closed, and the component package is dried until completely dehydrated. It can then be hoisted onto the transfer cart 3 and returned to the air preheater.

[0034] After all component packages are cleaned, the residual alkali solution in the soaking tank 4 needs to be neutralized before discharge. Hydrochloric acid or the like can be used for neutralization to control the pH value to be within 8. It can also be treated together with the desulfurization waste liquid from the power plant.

[0035] The above are preferred embodiments of the present invention. Those skilled in the art may make various changes or improvements based on the above. Without departing from the overall concept of the present invention, these changes or improvements should fall within the scope of protection required by the present invention.

Claims

1. A mobile air preheater heat transfer element package flushing and drying system, characterized by: The invention comprises a mobile device with a cavity, wherein an alkali solution soaking box (4) for pre-treating a component package, a rinsing box (5) for rinsing the component package, a recovery box (6) for recovering rinsing water, an alkali removal box (7) for removing alkaline water residue in the component package, and a drying box (8) are arranged in the mobile device. The component package is rinsed and dried by passing through each station in sequence.

2. The mobile air preheater heat transfer element package flushing and drying system according to claim 1, characterized in that: The moving device is also provided with a lifting device for moving the heat transfer element package to be cleaned.

3. The mobile air preheater heat transfer element package flushing and drying system according to claim 1 or 2, characterized in that: The trailer box (1) comprises a box-shaped vehicle shell (1.4), the interior of which is provided with a bottom plate (1.2), a detachable upper and lower step ladder (1.3), a water inlet main pipe (1.5) connected to an external water source at one end, a sewage main pipe (1.6) connected to an external sewage discharge area at one end, and an electric control box (1.7); wheels (1.1) are installed on the outer bottom of the box-shaped vehicle shell (1.4).

4. The mobile air preheater heat transfer element package flushing and drying system according to claim 1 or 2, characterized in that: The alkali solution soaking box comprises a soaking box body (4.1), inside of which are arranged stirring blades (4.2), a soaking box load-bearing grid (4.3), a soaking box water inlet pipe (4.4), a pH meter (4.5), a thermometer (4.6), and a soaking box sewage discharge pipe (4.7).

5. The mobile air preheater heat transfer element package flushing and drying system according to claim 1 or 2, characterized in that: The flushing box comprises a flushing box body (5.1), inside of which are arranged a flushing box load-bearing grid (5.2), a flushing box water inlet pipe (5.3), a cleaning pipe transmission structure, a low-pressure cleaning structure and a high-pressure cleaning structure connected to the cleaning pipe transmission structure, and a flushing pipe sewage discharge pipe (5.10).

6. The mobile air preheater heat transfer element package flushing and drying system according to claim 1 or 2, characterized in that: The recovery box comprises a recovery box body (6.1), inside of which a partition (6.2), a recovery box water inlet pump (6.3), a recovery box water outlet pump (6.4), and a recovery box sewage pipe (6.5) are arranged.

7. The mobile air preheater heat transfer element package flushing and drying system according to claim 1 or 2, characterized in that: The dealkali removal box comprises a dealkali removal box body (7.1), inside of which are arranged a dealkali removal box load-bearing grid (7.2), a water spray pipe driving structure, a water spray pipe (7.3) connected to the water spray pipe driving structure, a dealkali removal box water inlet pipeline (7.6), a dealkali removal box drainage pump (7.7), and a dealkali removal box sewage discharge pipeline (7.8).

8. The mobile air preheater heat transfer element package flushing and drying system according to claim 1 or 2, characterized in that: The drying box comprises a drying box body (8.1), inside of which are arranged a drying box load-bearing grid (8.2), a blowing structure, an electric heating pipe group (8.6) and a drying box sewage discharge pipeline (8.7).

9. The mobile air preheater heat transfer element package flushing and drying system according to claim 2, characterized in that: The lifting device comprises a crossbeam (2.3) arranged at an upper position inside the moving device; a retractable structure is arranged at the bottom of the crossbeam (2.3); the bottom of the retractable structure is fixed and is used to adjust the height of the crossbeam (2.3); a track beam (2.4) pointing to the inside of the moving device is also arranged on the crossbeam (2.3); the track beam (2.4) slides horizontally along the crossbeam (2.3) to drive the component package to move between various workstations.

10. The mobile air preheater heat transfer element package flushing and drying system according to claim 9, characterized in that: Electric hoists (2.5) are provided at both ends of the crossbeam (2.3), and the electric hoists (2.5) are connected to hooks (2.6) for driving a trolley (3) on which a component package is placed to move to the track beam (2.4).

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