Outdoor epoxy powder spraying equipment and construction method

Abstract

The invention belongs to the technical field of steel pipe anti-corrosion treatment equipment, and particularly relates to outdoor epoxy powder spraying equipment and a construction method. The equipment comprises a rotating base, a clamping base, a rotating cylinder, a dispersing mechanism, a driving mechanism, a pressure bin and an electrostatic spraying machine. The method comprises the steps of fixation of additional equipment, humidity control, spraying, drying and the like. The defect that after the outdoor steel pipe is welded, the spraying effect is poor due to the fact that epoxy powder is sprayed through a spray gun of existing equipment under the influence of wind power and humidity factors is overcome, the problem that epoxy powder sprayed through a conventional spray gun is uneven in distribution is solved, and the effect of spraying epoxy powder to the welding position of the outdoor steel pipe can be remarkably improved; and the epoxy powder spraying and coating drying line production is achieved, the spraying effect is guaranteed, meanwhile, the construction efficiency is improved, and the device is worthy of application and popularization in the high-quality steel pipe welding corrosion prevention field.

Description

Technical Field

[0001] The invention belongs to the technical field of steel pipe anti-corrosion treatment equipment, and particularly relates to outdoor epoxy powder spraying equipment and a construction method. Background Art

[0002] Electrostatic powder sprayers (electrostatic sprayers) are commonly used epoxy powder coating equipment on the market. Their mechanism is as follows: During electrostatic spraying, the spray gun or spray cup is connected to a negative electrode, while the workpiece is connected to a positive electrode and ground. The high voltage generated by a high-voltage electrostatic generator creates an electrostatic field between the tip of the spray gun (or spray plate, or spray cup) and the workpiece. The force exerted on the paint particles in this electric field is related to the voltage of the electrostatic field and the charge of the paint particles, and is inversely proportional to the distance between the spray gun and the workpiece. When the voltage reaches a certain level, the air near the spray gun tip becomes ionized, resulting in intense ionization and heating. This creates a dark red halo around the sharp edge of the spray gun tip or the electrode needle, which is particularly noticeable in the dark. At this time, the corona discharge in the air also becomes extremely intense. Film-forming materials in paint, such as resins and pigments, are primarily composed of high-molecular-weight organic compounds, most of which are conductive dielectrics. Paints also contain organic solvents, cosolvents, curing agents, electrostatic diluents, and other additives. Most of these solvents, such as benzene, xylene, and gasoline, are polar and have low resistivity, resulting in a certain degree of conductivity. These substances enhance the coating's charging properties. The molecular structure of dielectrics can be categorized as polar or non-polar. Under the influence of an electric field, polar molecules exhibit electrical properties, while non-polar molecules acquire electrical polarity, attracting conductive charges and causing localized charge formation on the dielectric surface within the applied electric field. When the paint is atomized and sprayed through a nozzle, it becomes charged by contact with the nozzle's electrode needle or the edge of the spray disc or cup. When these negatively charged paint particles enter the gas ionization zone generated by the corona discharge, their surface charge density increases again. Under the influence of the electrostatic field, these negatively charged paint particles are moved toward the workpiece surface and deposited there, forming a uniform coating film.

[0003] After welding outdoor steel pipes, epoxy powder needs to be sprayed to improve the corrosion resistance of the welded parts. However, most of the existing epoxy powder spraying equipment works indoors. Due to the uncontrollable outdoor wind force, the construction is difficult. This is reflected in the following aspects: when the wind force is strong, the powder will deviate from the preset direction and cannot reach the preset spraying position. At the same time, the wind force against the wind will also increase the resistance of the powder, making the powder's stroke smaller. When the wind is with the wind, the powder is easy to disperse, weakening the spraying effect. When there is a lot of dust in the air, it will have a significant impact on the spraying effect of the epoxy powder. On the other hand, the wind factor is also an external factor that makes it difficult to control temperature and humidity, which also affects the spraying effect. The existing spray gun sprays in the form of an atomized gas beam, which easily leads to uneven spraying. Summary of the Invention

[0004] The present invention discloses an outdoor epoxy powder spraying device and a construction method. Based on the existing electrostatic sprayer, by adding external equipment, the device can be applied to the steel pipe welding anti-corrosion construction in outdoor places. Based on the design of the external equipment, the present invention avoids the influence of wind and humidity factors on the spraying effect and further improves the spraying quality.

[0005] To achieve the above purpose, the technical solution of this invention is:

[0006] An outdoor epoxy powder spraying equipment includes an external device, the external device includes a pressure chamber connected to the barrel of an electrostatic spray gun, the pressure chamber is covered on the outside of a welded steel pipe and is used to spray the surface of the welded part, a plurality of nozzles are evenly distributed on the inner surface of the pressure chamber, the nozzle is made of a high-temperature resistant insulating material, and includes a cylinder, a piston, a compression spring, a stud, and a nozzle, the top of the cylinder is connected to the pressure chamber, the bottom of the cylinder is screwed with a stud, the top of the stud is connected to the bottom of the piston through a compression spring, the piston is sealed and slidably connected to the inner wall of the cylinder, and the An annular limit block is provided at the top of the inner wall of the cylinder, and an annular pressure sensor is fixedly connected to the bottom of the annular limit block. A plurality of nozzles inclined downward are evenly distributed on the upper part of the side wall of the cylinder. When the top of the piston contacts the annular pressure sensor, the inner port of the nozzle is closed. A limit column is provided at the center of the top of the stud, and a pressure sensor is provided at the top of the limit column. When the bottom end of the piston contacts the pressure sensor, the top of the piston is aligned with the lower edge of the inner port of the nozzle, and the nozzle is fully opened. The length of the stud satisfies: the initial length of the compression spring is regulated by adjusting the length entering the cylinder.

[0007] Preferably, the welded steel pipe constitutes an "I"-shaped steel pipe, and the external equipment also includes a rotating base arranged on the steel pipe walls on both sides of the weld, and a clamping base coaxially arranged on the outside of the rotating base. The pressure chamber is connected between the two clamping bases, and a rotating cylinder is rotatably connected between the rotating base and the clamping base. The rotating cylinder is rotatably connected to the outer edge of the rotating base and the inner edge of the clamping base through an inner slip ring and an outer slip ring symmetrically arranged on the inner and outer surfaces. The rotating cylinder is provided with a dispersing mechanism for evenly dispersing epoxy powder, and one end of the rotating cylinder is connected to the clamping base through a driving mechanism.

[0008] Preferably, the rotating base includes two first hoops, the first hoops include a semicircular upper hoop body and a lower hoop body, the side walls at both ends of the upper hoop body and the lower hoop body are respectively provided with a first connecting plate folded outward, the first connecting plates of the upper hoop body and the lower hoop body are opposite to each other, and are respectively provided with a first connecting hole, the inner surfaces of the upper hoop body and the lower hoop body are respectively provided with an elastic rubber layer, the upper hoop body and the lower hoop body are covered on the outer wall of the steel pipe, and are locked on the outer wall of the steel pipe by a first bolt passing through the first connecting hole and a first nut tightened on the first bolt, the circumferential surfaces of the upper hoop body and the lower hoop body are respectively coaxially provided with a first semi-annular slide groove, and the two first semi-annular slide grooves are connected to form a complete lower annular slide groove.

[0009] The lockhole that is formed on the upper surface of the second rim is formed on the upper surface of the second rim, and the lockhole that is formed on the lower surface of the second rim is formed on the lower surface of the second rim.

[0010] Preferably, the rotating cylinder includes a semicircular upper cylinder and a lower cylinder, and the inner slip ring and the outer slip ring respectively include a semicircular semicircular inner slip ring provided on the inner surface of the upper cylinder and the lower cylinder and a semicircular semicircular outer slip ring provided on the outer surface of the upper cylinder and the lower cylinder. The upper cylinder and the lower cylinder are butted together to form a complete rotating cylinder, the two semicircular inner slip rings on the same side are butted together to form a complete inner slip ring, and the two semicircular outer slip rings on the same side are butted together to form a complete outer slip ring. The outer slip ring is slidably connected to the upper annular groove, and the inner slip ring is slidably connected to the lower annular groove. The rotating cylinder is clamped and limited between the rotating base and the clamping base by the inner slip ring and the outer slip ring.

[0011] Preferably, the inner walls of the upper annular chute and the lower annular chute are provided with a graphene coating or are evenly embedded with ball structures, and the cross-sections of the inner sliding ring and the outer sliding ring are "convex"; the driving mechanism includes a driven gear coaxially fixed to the outer surface of one end of the rotating cylinder, a handle is connected between the top ends of the two upper hoop arms, one end of the handle is connected to a mounting seat, a servo motor is fixed to the bottom of the mounting seat, the output shaft of the servo motor is fixedly connected to a driving gear, and the driving gear is meshed with the driven gear.

[0012] Preferably, the dispersion mechanism includes a plurality of axially arranged rectangular through grooves evenly distributed around the axis in the middle of the rotating cylinder, the rotating cylinder wall between adjacent rectangular through grooves constitutes a back-ribbed structure, the inner surface of the back-ribbed structure is integrally formed with a guide plate, the guide plate is inclined toward one side of the outer wall of the steel pipe, and is used to guide the epoxy powder atomized gas to the outer wall of the steel pipe, the rotating cylinder and the guide plate are respectively made of high-temperature resistant insulating materials, and the rectangular through grooves are used in conjunction with the nozzle.

[0013] Preferably, the outer walls of the upper pressure chamber and the lower pressure chamber are respectively connected with a powder feed pipe and an air feed pipe, and the powder feed pipe and the air feed pipe are respectively connected with the barrel of the spray gun and the high-temperature pressure gas conveying equipment, and the upper hoop body and the lower hoop body are respectively provided with a ventilation pipe.

[0014] Preferably, a humidity sensor is provided on the inner surface of the pressure chamber, and the humidity sensor, annular pressure sensor, pressure sensor, servo motor, and high-temperature pressure gas delivery equipment are electrically connected to the control module of the electrostatic sprayer through wires.

[0015] A construction method for outdoor epoxy powder spraying equipment comprises the following steps:

[0016] (1) Install the two first clamps of the rotating base on the steel pipe wall on both sides of the welded steel pipe to be sprayed, ensuring that the rotating base is firmly connected to the steel pipe wall, connect the upper and lower half cylinders to the lower annular slide groove through the inner sliding ring and connect the outer sliding ring to the upper annular slide groove, lock the clamping base with the second bolt and the second nut, and ensure that the driving gear and the driven gear are meshed with each other;

[0017] (2) The control module determines the humidity in the space between the pressure chamber and the steel pipe based on the information from the humidity sensor. When the humidity is greater than the preset value, the high-temperature pressure gas delivery equipment is started to reduce the humidity value to the set range by blowing hot air; when the humidity is lower than the preset value, water is manually sprayed from the ventilation pipe into the space between the pressure chamber and the steel pipe through a water gun to ensure that the spraying environment meets the humidity requirements;

[0018] (3) Spraying begins according to the preset parameters of the electrostatic sprayer. When the epoxy powder airflow pressure reaches the set minimum value, the piston overcomes the elastic force of the compression spring and begins to move. When the pressure sensor detects the pressure value, the nozzle is fully opened. The control module controls the airflow of the electrostatic sprayer's spray gun to control the value of the pressure sensor within the set maximum value. When the nozzle begins to open, the servo motor is turned on to evenly disperse the epoxy powder on the outer wall of the steel pipe through the guide plate.

[0019] (4) After spraying for the preset time, turn off the electrostatic sprayer, turn on the high-temperature pressure gas delivery equipment, and dry the coating. After drying for the set time, turn off the high-temperature pressure gas delivery equipment and remove the additional equipment from the steel pipe.

[0020] Preferably, the construction method also includes a method for screening the set minimum value and set maximum value of the epoxy powder airflow pressure and the speed of the servo motor, including: according to the quality after spray molding, selecting the set minimum value and set maximum value and the speed of the servo motor that can achieve the best effect as construction parameters. During the screening process, by screwing the stud, the length of the stud entering the cylinder is controlled to obtain compression springs with different compression lengths, and then obtain different values of the annular pressure sensor and different values of the pressure sensor, and in this case, a spraying experiment is carried out to obtain the optimal construction parameters by changing the speed of the servo motor.

[0021] The beneficial effects of the outdoor epoxy powder spraying equipment and construction method of the present invention are:

[0022] The present invention overcomes the defect that epoxy powder sprayed by the spray gun of existing equipment after outdoor steel pipe welding is affected by wind and humidity factors, resulting in poor spraying effect, and solves the problem of uneven distribution of epoxy powder sprayed by conventional spray guns. It can significantly improve the effect of spraying epoxy powder at the welding position of outdoor steel pipes, and the flow operation of spraying epoxy powder and drying the coating improves construction efficiency while ensuring the spraying effect. It is worthy of promotion and use in the field of high-quality steel pipe welding anti-corrosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure from a front view of an embodiment of the present invention.

[0024] Figure 2 This invention Figure 1 Left view of .

[0025] Figure 3 It is a structural schematic diagram of the rotating base of the present invention assembled on a steel pipe.

[0026] Figure 4 It is a front view structural schematic diagram of the rotating drum of the present invention.

[0027] Figure 5 It is a side view structural diagram of the cooperation between the rotating drum and the steel pipe of the present invention.

[0028] Figure 6 It is a schematic diagram of the top view of the lower pressure chamber of the present invention.

[0029] Figure 7 It is a schematic cross-sectional structural diagram of the nozzle of the present invention.

[0030] Figure 8 It is a front view structural schematic diagram of the nozzle of the present invention.

[0031] The figure shows: 01-position to be sprayed, 1-pressure chamber, 11-upper pressure chamber, 12-lower pressure chamber, 101-powder inlet pipe, 102-air inlet pipe, 103-outer wall of lower pressure chamber, 104-nozzle, 1041-cylinder, 1042-annular limit block, 1043-annular pressure sensor, 1044-piston, 1045-nozzle, 1046-compression spring, 1047-stud, 1048-limit column, 1049-pressure sensor, 2-handle, 3-mounting seat, 4-servo motor, 5-driving gear, 6-rotating cylinder, 61-upper cylinder, 62-lower cylinder, 63-driven gear, 64-inner sliding ring, 65-outer sliding ring, 66-rectangular through groove, 67-back rib structure, 68-guide plate, 7-clamping base, 71-upper hoop arm, 72-lower hoop arm, 73-second connecting plate, 74-second semi-annular chute, 8-steel pipe, 9-rotating base, 91-ventilation pipe, 92-first connecting plate, 93-elastic rubber layer, 94-lower annular chute, 901-upper hoop body, 902-lower hoop body. DETAILED DESCRIPTION

[0032] The following description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0033] The following embodiments may be understood as individually expressing a part of a local structure or method of the present invention, or may be understood as a combination of the embodiments to explain the connotation of a larger structure or method of the present invention.

[0034] Example 1

[0035] An outdoor epoxy powder spraying equipment, such as Figure 1-8 As shown, it includes an additional device, which includes a pressure chamber connected to the barrel of the spray gun of an electrostatic sprayer (a commonly used device, not shown in the figure) for storing pressurized gas containing epoxy powder. The pressure chamber is coated on the outside of the welded steel pipe and is used to spray the surface of the welded portion. Since the welded steel pipe has a variety of shapes, such as straight and T-shaped, a pressure chamber that can cover the welded portion can be designed according to the shape of the steel pipe, that is, two symmetrical half-shells are connected to form a complete coating structure, each half-shell is hollow, and the hollow portion is the pressure chamber;

[0036] For further reference, Figure 6-8As shown, a number of nozzles 104 are evenly distributed on the inner surface of the pressure chamber. The nozzles 104 are made of high-temperature resistant insulating material (such as ceramic material or an insulating layer provided on the surface of a metal material), including a cylinder 1041, a piston 1044, a compression spring 1046, a stud 1047, and a nozzle 1045. The top of the cylinder 1041 is connected to the pressure chamber, and the bottom end of the cylinder 1041 is screwed with a stud 1047. The top end of the stud 1047 is connected to the bottom end of the piston 1044 through a compression spring 1046. The piston 1044 is sealed and slidably connected to the inner wall of the cylinder 1041. The top end of the inner wall of the cylinder 1041 is provided with an annular limit block 1042, and the bottom of the annular limit block 1042 is fixedly connected There is an annular pressure sensor 1043, and a plurality of downward-inclined nozzles 1045 are evenly distributed on the upper part of the side wall of the cylinder 1041. When the top end of the piston 1044 contacts the annular pressure sensor 1043, the inner port of the nozzle 1045 is closed. A limiting column 1048 is provided at the center of the top of the stud 1047, and a pressure sensor 1049 is provided on the top of the limiting column 1048. When the bottom end of the piston 1044 contacts the pressure sensor 1049, the top end of the piston 1044 is aligned with the lower edge of the inner port of the nozzle 1045, and the nozzle 1045 is fully opened. The length of the stud 1047 satisfies: the initial length of the compression spring 1046 is regulated by adjusting the length entering the cylinder 1041. It is understandable that the shorter the compression spring, the greater its elastic force. In other words, overcoming the initial elastic force of the compression spring is a necessary condition for opening the nozzle. At this time, the pressure of the pressurized gas in the cylinder is the set minimum value. To fully open the nozzle, it is necessary to further increase the pressure of the pressurized air to further shorten the compression spring. At this time, the bottom end of the piston contacts the pressure sensor. In actual use, the nozzle should be kept 15-30 cm away from the position of the steel pipe to be sprayed. According to the difference in spraying quality, the depth of the stud screwed into the cylinder can be adjusted (such as Figure 8 As shown, the outer wall of the stud is provided with a scale for marking the screw-in depth) and the set minimum value is fixed by the initial elastic force of the compression spring. At this time, the annular pressure sensor can synchronously detect the set minimum value, which keeps a corresponding relationship with the initial expansion and contraction of the compression spring. Since excessive airflow pressure will also lead to reduced spraying quality, the value of the pressure sensor can be used as a reference data for controlling the set maximum value of the airflow pressure, so that the airflow pressure ejected from the nozzle can be accurately controlled by the control module of the electrostatic sprayer, so that it is fixed within the range between the set minimum value and the set maximum value to ensure the best spraying effect. Since a pressure chamber covering the steel pipe is provided, the influence of external wind factors on the spraying is avoided. Since the nozzles are evenly distributed, it is ensured that the steel pipe surface can be evenly sprayed. Since the distance between the nozzle and the steel pipe surface and the pressure value of the compressed air are controlled, a good spraying effect is guaranteed.

[0037] Example 2

[0038] like Figure 1-8 As shown, in order to further illustrate the present invention, an expanded explanation is now given based on a steel pipe welding form: the welded steel pipe constitutes an "I"-shaped steel pipe, and the external equipment also includes a rotating base 9 provided on the steel pipe wall on both sides of the weld, and a clamping base 7 coaxially provided on the outside of the rotating base 9. The pressure chamber 1 is connected between the two clamping bases 7, and a rotating cylinder 6 is rotatably connected between the rotating base 9 and the clamping base 7. The rotating cylinder 6 is rotatably connected to the outer edge of the rotating base 9 and the inner edge of the clamping base 7 through an inner slip ring 64 and an outer slip ring 65 symmetrically provided on the inner and outer surfaces. The rotating cylinder 6 is provided with a dispersing mechanism for evenly dispersing epoxy powder, and one end of the rotating cylinder 6 is connected to the clamping base 7 through a driving mechanism.

[0039] In this embodiment, although a certain degree of uniform spraying can be achieved by spraying epoxy powder through several evenly arranged nozzles, there is still unevenness between the center and periphery of the epoxy powder beam sprayed from the nozzle. Although the epoxy powder can be dispersed on the surface of the steel pipe due to its own charge, uniform spraying cannot be achieved between the epoxy powder spray points (including the center and periphery of the spray points). Therefore, the present invention provides a dispersion mechanism to evenly disperse the epoxy powder airflow between the pressure chamber and the steel pipe wall to the steel pipe surface to achieve a more ideal effect. It should be noted that the present invention is designed to provide a high-quality anti-corrosion effect and is suitable for workpieces with high anti-corrosion requirements.

[0040] Example 3

[0041] like Figure 2 、 3 As shown, the rotating base 9 includes two first hoops, and the first hoops include a semicircular upper hoop body 901 and a lower hoop body 902. The side walls at both ends of the upper hoop body 901 and the lower hoop body 902 are respectively provided with a first connecting plate 92 folded outward, and the first connecting plates 92 of the upper hoop body 901 and the lower hoop body 902 are opposite to each other and are respectively provided with a first connecting hole (not drawn in the figure). The inner surfaces of the upper hoop body 901 and the lower hoop body 902 are respectively provided with an elastic rubber layer 93. The upper hoop body 901 and the lower hoop body 902 are covered on the outer wall of the steel pipe 8 and are locked on the outer wall of the steel pipe 8 by a first bolt passing through the first connecting hole and a first nut tightened on the first bolt. The circumferential surfaces of the upper hoop body 901 and the lower hoop body 902 are respectively coaxially provided with a first semi-annular slide groove, and the two first semi-annular slide grooves are connected to form a complete lower annular slide groove 94.

[0042] like Figure 1 、 2As shown in , 6, the clamping base 7 includes two groups of second clamps, the second clamp includes a semicircular upper clamp arm 71 and a lower clamp arm 72, the two free ends of the upper clamp arm 71 and the lower clamp arm 72 are respectively provided with a second connecting plate 73 folded radially outward, the second connecting plates 73 of the upper clamp arm 71 and the lower clamp arm 72 are opposite to each other and are respectively provided with a second connecting hole, the inner surfaces of the upper clamp arm 71 and the lower clamp arm 72 are coaxially provided with a second semi-annular slide groove 74 along the circumference, and the two second semi-annular slide grooves 74 are connected to form a complete upper annular slide groove, and the second clamp is sleeved on the outside of the first clamp and coaxially arranged. The pressure chamber 1 includes a semicircular upper pressure chamber 11 and a lower pressure chamber 12, the upper pressure chamber 11 and the lower pressure chamber 12 are respectively connected between the two upper clamp arms 71 or the two lower clamp arms 72, and the upper pressure chamber 11 and the lower pressure chamber 12 are connected to form a complete pressure chamber 1, and the one-to-one opposite second connecting plates 73 are locked by a second bolt and a second nut.

[0043] like Figure 1 、 2 As shown in Figures 4 and 5, the rotating cylinder 6 includes a semicircular upper cylinder 61 and a lower cylinder 62, and the inner slip ring 64 and the outer slip ring 65 respectively include a semicircular semicircular inner slip ring provided on the inner surface of the upper cylinder 61 and the lower cylinder 62 and a semicircular semicircular outer slip ring provided on the outer surface of the upper cylinder 61 and the lower cylinder 62. The upper cylinder 61 and the lower cylinder 62 are butted together to form a complete rotating cylinder 6, and the two semicircular inner slip rings on the same side are butted together to form a complete inner slip ring 64, and the two semicircular outer slip rings on the same side are butted together to form a complete outer slip ring 65. The outer slip ring 65 is slidably connected to the upper annular groove, and the inner slip ring 64 is slidably connected to the lower annular groove. The rotating cylinder 6 is clamped and limited between the rotating base 9 and the clamping base 7 by the inner slip ring 64 and the outer slip ring 65.

[0044] As described above, the rotating base can rotate relative to the rotating base and the clamping base, thereby achieving the effect of dispersing the epoxy powder. At the same time, due to the mutual limitation between the inner slip ring and the lower annular groove and the mutual limitation between the outer slip ring and the upper annular groove, the structural stability of the external equipment can be guaranteed when it is working.

[0045] Example 4

[0046] like Figure 1-6As shown, the inner walls of the upper and lower annular chutes 94 are provided with a graphene coating or are evenly embedded with ball structures, and the cross-sections of the inner and outer sliding rings 64 and 65 are "convex"; as set above, the relative sliding can be smooth and the structure can be stable; the driving mechanism includes a driven gear 63 coaxially fixed to the outer surface of one end of the rotating cylinder 6, a handle 2 is connected between the tops of the two upper hoop arms 71, and one end of the handle 2 is connected to a mounting base 3. A servo motor 4 is fixed to the bottom of the mounting base 3, and the output shaft of the servo motor 4 is fixedly connected to a driving gear 5, which is meshed with the driven gear 63. The rotation of the rotating cylinder is controlled by the servo motor to achieve better control of the spraying effect.

[0047] Example 5

[0048] like Figure 4 、 5 As shown, the dispersion mechanism includes a plurality of axially arranged rectangular through slots 66 evenly distributed around the axis in the middle of the rotating cylinder 6, and the rotating cylinder wall between adjacent rectangular through slots 66 forms a back rib structure 67. The inner surface of the back rib structure 67 is integrally formed with a guide plate 68, and the guide plate 68 is inclined to one side of the outer wall of the steel pipe 8 (as shown in FIG. Figure 5 As shown), and is used to guide the epoxy powder atomized gas to the outer wall of the steel pipe 8. The rotating cylinder 6 and the guide plate 68 are made of high-temperature resistant insulating materials, and the rectangular through groove 66 is used in conjunction with the nozzle 104.

[0049] In this embodiment, the nozzle 104 sprays epoxy powder atomizing gas, which enters the rotating cylinder through the rectangular through-groove. The gas entering is evenly dispersed around the outer periphery of the steel pipe 8 under the rotation of the guide plate, and is continuously pushed toward the outer wall of the steel pipe, thereby overcoming the problem of uneven distribution of epoxy powder caused by the existing gas beam method and further improving the spraying effect. It should be noted that the speed of the servo motor also controls the contact force between the epoxy powder and the surface of the steel pipe. The higher the speed, the faster the guide plate drives the epoxy particles to move toward the surface of the steel pipe, that is, the greater the contact force; at the same time, the guide plate also has the effect of further atomization, which can make the epoxy powder particles reach a smaller size, which is conducive to promoting the epoxy powder particles to reach a size with better spraying effect. In other words, the present invention can use relatively large epoxy powder particles to achieve the spraying effect of small-sized epoxy powder particles.

[0050] Example 6

[0051] like Figure 1 、 2As shown, the outer walls of the upper pressure chamber 11 and the lower pressure chamber 12 are respectively connected to a powder feed pipe 101 and an air intake pipe 102, and the powder feed pipe 101 and the air intake pipe 102 are respectively connected to the barrel of the spray gun and the high-temperature pressure gas delivery equipment, and the upper hoop body 901 and the lower hoop body 902 are respectively provided with a ventilation pipe 91.

[0052] A humidity sensor is provided on the inner surface of the pressure chamber. The humidity sensor, annular pressure sensor, pressure sensor, servo motor and high-temperature pressure gas delivery equipment are electrically connected to the control module of the electrostatic sprayer through wires.

[0053] In this embodiment, the epoxy powder particles discharged from the gun barrel carry an electric charge and enter the powder inlet pipe, and then into the pressure chamber. When the pressure in the pressure chamber reaches a set minimum value, the nozzle opens, and the electrostatic sprayer's pressure regulation ensures that the nozzle's spray pressure is always maintained between the set minimum and maximum values. Excess epoxy powder particles are discharged through a vent pipe, which can be connected to a recovery device for recycling the discharged epoxy powder particles. The high-temperature pressure gas conveying equipment is mainly used for drying after the powder spraying is completed.

[0054] Example 7

[0055] Based on the above embodiments, this embodiment discloses a construction method of an outdoor epoxy powder spraying equipment, such as Figure 1-8 As shown, the following steps are included:

[0056] (1) Figure 3 As shown, the two first clamps of the rotating base 9 are installed on the steel pipe walls on both sides of the welded steel pipe to be sprayed position 01 to ensure that the rotating base 9 is firmly connected to the steel pipe wall, the upper half cylinder 61 and the lower half cylinder 62 are connected to the lower annular groove 94 through the inner sliding ring 64, and the outer sliding ring 65 is connected to the upper annular groove. The clamping base 7 is locked with the second bolt and the second nut to ensure that the driving gear 5 and the driven gear 63 are meshed with each other;

[0057] (2) The control module determines the humidity in the space between the pressure chamber 1 and the steel pipe 8 based on the information from the humidity sensor. When the humidity is greater than the preset value, the high-temperature pressure gas delivery device is activated to reduce the humidity value to the set range by blowing hot air; when the humidity is lower than the preset value, water is manually sprayed from the ventilation pipe into the space between the pressure chamber and the steel pipe through a water gun to ensure that the spraying environment meets the humidity requirements;

[0058] (3) Spraying begins according to the preset parameters of the electrostatic sprayer. When the epoxy powder airflow pressure reaches the set minimum value, the piston 1044 overcomes the elastic force of the compression spring 1046 and begins to move. When the pressure sensor 1049 detects the pressure value, the nozzle is fully opened. The control module controls the airflow of the electrostatic sprayer's spray gun to control the value of the pressure sensor within the set maximum value. When the nozzle begins to open, the servo motor 4 is turned on (the operator holds the handle) and the epoxy powder is evenly dispersed on the outer wall of the steel pipe 8 through the guide plate 68.

[0059] (4) After spraying for the preset time, turn off the electrostatic sprayer, turn on the high-temperature pressure gas delivery equipment, and dry the coating. After drying for the set time, turn off the high-temperature pressure gas delivery equipment and remove the additional equipment from the steel pipe.

[0060] The present embodiment omits some conventional steps, such as grounding the steel pipe and pre-treatment of the area to be sprayed, and the unmentioned contents are solved by existing solutions. As described above, the present invention can achieve high-quality spraying and drying of the coating, thereby improving construction efficiency while ensuring spraying quality.

[0061] Example 8

[0062] Based on Example 7, this embodiment discloses: the construction method also includes a method for screening the set minimum value and set maximum value of the epoxy powder airflow pressure and the speed of the servo motor, including: according to the quality after spray molding, selecting the set minimum value and set maximum value that can achieve the best effect and the speed of the servo motor as construction parameters. During the screening process, by screwing the stud, the length of the stud entering the barrel is controlled to obtain compression springs with different compression lengths, and then obtain different values of the annular pressure sensor and different values of the pressure sensor, and in this case, a spraying experiment is carried out to obtain the optimal construction parameters by changing the speed of the servo motor.

[0063] The present invention provides an additional device that is different from conventional spray gun spraying, and on the basis of this device, the optimal working parameters of the additional device are obtained in the above manner, thereby further improving the spraying effect.

Claims

1. An outdoor epoxy powder spraying equipment, characterized by: The invention comprises an additional device, wherein the additional device comprises a pressure chamber connected to the barrel of the electrostatic spray gun, the pressure chamber is covered on the outside of the welded steel pipe and is used to spray the surface of the welded part, a plurality of nozzles are evenly distributed on the inner surface of the pressure chamber, and the nozzle is made of high temperature resistant insulating material, including a cylinder, a piston, a compression spring, a stud, and a nozzle, the top of the cylinder is connected to the pressure chamber, the bottom of the cylinder is screwed with a stud, the top of the stud is connected to the bottom of the piston through a compression spring, the piston is sealed and slidably connected to the inner wall of the cylinder, and the top of the inner wall of the cylinder is connected to the pressure chamber. An annular limit block is provided, and an annular pressure sensor is fixedly connected to the bottom of the annular limit block. A plurality of nozzles inclined downward are evenly distributed on the upper part of the side wall of the cylinder. When the top of the piston contacts the annular pressure sensor, the inner port of the nozzle is closed. A limit column is provided at the center of the top of the stud, and a pressure sensor is provided at the top of the limit column. When the bottom end of the piston contacts the pressure sensor, the top end of the piston is aligned with the lower edge of the inner port of the nozzle, and the nozzle is fully opened. The length of the stud satisfies: the initial length of the compression spring is regulated by adjusting the length entering the cylinder.

2. An outdoor epoxy powder spraying equipment as claimed in claim 1, characterized in that: The welded steel pipe constitutes an "I"-shaped steel pipe. The external equipment also includes a rotating base arranged on the steel pipe walls on both sides of the weld and a clamping base coaxially arranged on the outside of the rotating base. The pressure chamber is connected between the two clamping bases, and a rotating cylinder is rotatably connected between the rotating base and the clamping base. The rotating cylinder is rotatably connected to the outer edge of the rotating base and the inner edge of the clamping base through an inner slip ring and an outer slip ring symmetrically arranged on the inner and outer surfaces. The rotating cylinder is provided with a dispersing mechanism for evenly dispersing epoxy powder, and one end of the rotating cylinder is connected to the clamping base through a driving mechanism.

3. An outdoor epoxy powder spraying equipment as claimed in claim 2, characterized in that: The rotating base includes two first hoops, which include a semicircular upper hoop body and a lower hoop body. The side walls at both ends of the upper hoop body and the lower hoop body are respectively provided with a first connecting plate folded outward. The first connecting plates of the upper hoop body and the lower hoop body are opposite to each other and are respectively provided with a first connecting hole. The inner surfaces of the upper hoop body and the lower hoop body are respectively provided with an elastic rubber layer. The upper hoop body and the lower hoop body are covered on the outer wall of the steel pipe and are locked on the outer wall of the steel pipe by a first bolt passing through the first connecting hole and a first nut tightened on the first bolt. The circumferential surfaces of the upper hoop body and the lower hoop body are respectively coaxially provided with a first semi-annular slide groove, and the two first semi-annular slide grooves are connected to form a complete lower annular slide groove.

4. An outdoor epoxy powder spraying equipment as claimed in claim 3, characterized in that: The clamping base includes two groups of second clamps, and the second clamp includes a semicircular upper clamp arm and a lower clamp arm, and the two free ends of the upper clamp arm and the lower clamp arm are respectively provided with a second connecting plate folded radially outward, and the second connecting plates of the upper clamp arm and the lower clamp arm are opposite to each other and respectively provided with a second connecting hole, and the inner surfaces of the upper clamp arm and the lower clamp arm are coaxially provided with a second semi-annular slide groove along the circumference, and the two second semi-annular slide grooves are butted to form a complete upper annular slide groove, and the second clamp is sleeved on the outside of the first clamp and coaxially arranged, and the pressure chamber includes a semicircular upper pressure chamber and a lower pressure chamber, and the upper pressure chamber and the lower pressure chamber are respectively connected between the two upper clamp arms or the two lower clamp arms, and the upper pressure chamber and the lower pressure chamber are butted to form a complete pressure chamber, and the one-to-one opposite second connecting plates are locked by a second bolt and a second nut.

5. An outdoor epoxy powder spraying equipment as claimed in claim 4, characterized in that: The rotating cylinder includes a semicircular upper cylinder and a lower cylinder, and the inner and outer sliding rings include a semicircular inner sliding ring provided on the inner surface of the upper and lower cylinders and a semicircular outer sliding ring provided on the outer surface of the upper and lower cylinders respectively. The upper and lower cylinders are butted together to form a complete rotating cylinder, the two semicircular inner sliding rings on the same side are butted together to form a complete inner sliding ring, and the two semicircular outer sliding rings on the same side are butted together to form a complete outer sliding ring. The outer sliding ring is slidably connected to the upper annular chute, and the inner sliding ring is slidably connected to the lower annular chute. The rotating cylinder is clamped and limited between the rotating base and the clamping base by the inner and outer sliding rings.

6. An outdoor epoxy powder spraying equipment as claimed in claim 5, characterized in that: The inner walls of the upper annular chute and the lower annular chute are provided with a graphene coating or are evenly embedded with ball structures. The cross-sections of the inner sliding ring and the outer sliding ring are "convex"; the driving mechanism includes a driven gear coaxially fixed to the outer surface of one end of the rotating cylinder, a handle is connected between the top ends of the two upper hoop arms, one end of the handle is connected to a mounting seat, a servo motor is fixed to the bottom of the mounting seat, the output shaft of the servo motor is fixedly connected to a driving gear, and the driving gear is meshed with the driven gear.

7. An outdoor epoxy powder spraying equipment as claimed in claim 6, characterized in that: The dispersion mechanism includes a plurality of axially arranged rectangular through grooves evenly distributed around the axis in the middle of the rotating cylinder. The rotating cylinder wall between adjacent rectangular through grooves constitutes a back-ribbed structure. The inner surface of the back-ribbed structure is integrally formed with a guide plate. The guide plate is inclined toward one side of the outer wall of the steel pipe and is used to guide the epoxy powder atomized gas to the outer wall of the steel pipe. The rotating cylinder and the guide plate are respectively made of high-temperature resistant insulating materials, and the rectangular through grooves are used in conjunction with the nozzle.

8. An outdoor epoxy powder spraying equipment as claimed in claim 7, characterized in that: The outer walls of the upper and lower pressure chambers are connected with a powder feed pipe and an air feed pipe respectively, which are connected with the barrel of the spray gun and the high-temperature pressure gas delivery equipment respectively. The upper and lower hoop bodies are provided with ventilation pipes respectively.

9. An outdoor epoxy powder spraying equipment as claimed in claim 8, characterized in that: A humidity sensor is provided on the inner surface of the pressure chamber. The humidity sensor, annular pressure sensor, pressure sensor, servo motor and high-temperature pressure gas delivery equipment are electrically connected to the control module of the electrostatic sprayer through wires.

10. The construction method of an outdoor epoxy powder spraying equipment according to claim 9, characterized in that: The steps include: (1) Install the two first clamps of the rotating base on the steel pipe wall on both sides of the welded steel pipe to be sprayed, ensuring that the rotating base is firmly connected to the steel pipe wall, connect the upper and lower half cylinders to the lower annular slide groove through the inner sliding ring and connect the outer sliding ring to the upper annular slide groove, lock the clamping base with the second bolt and the second nut, and ensure that the driving gear and the driven gear are meshed with each other; (2) The control module determines the humidity in the space between the pressure chamber and the steel pipe based on the information from the humidity sensor. When the humidity is greater than the preset value, the high-temperature pressure gas delivery equipment is started to reduce the humidity value to the set range by blowing hot air; when the humidity is lower than the preset value, water is manually sprayed from the ventilation pipe into the space between the pressure chamber and the steel pipe through a water gun to ensure that the spraying environment meets the humidity requirements; (3) Spraying begins according to the preset parameters of the electrostatic sprayer. When the epoxy powder airflow pressure reaches the set minimum value, the piston overcomes the elastic force of the compression spring and begins to move. When the pressure sensor detects the pressure value, the nozzle is fully opened. The control module controls the airflow of the electrostatic sprayer's spray gun to control the value of the pressure sensor within the set maximum value. When the nozzle begins to open, the servo motor is turned on to evenly disperse the epoxy powder on the outer wall of the steel pipe through the guide plate. (4) After spraying for a preset time, turn off the electrostatic sprayer, turn on the high-temperature pressure gas delivery equipment, and dry the coating. After drying for a set time, turn off the high-temperature pressure gas delivery equipment and remove the additional equipment from the steel pipe; The construction method also includes a method for screening the set minimum value and set maximum value of the epoxy powder airflow pressure and the speed of the servo motor, including: based on the quality after spray molding, selecting the set minimum value and set maximum value and the speed of the servo motor that can achieve the best effect as construction parameters. During the screening process, by screwing the stud, the length of the stud entering the barrel is controlled to obtain compression springs with different compression lengths, and then obtain different values of the annular pressure sensor and different values of the pressure sensor, and in this case, a spraying experiment is carried out to obtain the optimal construction parameters by changing the speed of the servo motor.

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