A preheating device for wastewater treatment

Abstract

The present application relates to wastewater treatment technical field, specifically to a kind of preheating device for wastewater treatment, including preheating pipe, wastewater is heated after entering Venturi tube throat pipe by preheating pipe, here flow rate is sharply increased, static pressure is lowest, and stable static pressure difference is formed between left side preheating pipe, is introduced into piston pipe two ends by pressure tapping pipe, when daily high flow rate, left side static pressure is greater than right side, piston plate is pushed to right end, and flow rate is reduced after preheating pipe scale, and left and right pressure difference is reduced accordingly, piston plate is gradually reset to left, and make second friction plate and first friction plate engage, motor power is thus transmitted by transmission shaft, transmission belt and screw rod, drives strong magnetic ring axial movement, and strong magnetic ring is driven by magnetic force adsorption to move forward with internal adsorbed magnetic ring, rotating ring and scraper one, and scale is removed from pipe wall.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a preheating device for wastewater treatment. Background Technology

[0002] Industrial wastewater (such as wastewater from printing and dyeing, chemical, pharmaceutical, and food processing) usually contains high concentrations of organic matter, suspended solids, salts, and various pollutants. Direct discharge of such wastewater can cause serious damage to the environment. Therefore, it is necessary to systematically purify the wastewater to meet the national or local emission standards.

[0003] In existing wastewater preheating devices, changes in fluid velocity within the pipes are merely considered a passive indicator of scaling levels during operation. These velocity changes do not mechanically trigger descaling. As scaling worsens and flow velocity decreases, this velocity signal cannot be directly converted into a trigger for cleaning. The device is forced to allow scale to accumulate until severe blockage or a significant drop in heat exchange efficiency occurs, at which point manual intervention is required for shutdown and cleaning. Therefore, existing technology lacks a purely mechanical linkage mechanism that can automatically and adaptively initiate pipe wall descaling based on real-time flow velocity changes, resulting in delayed cleaning response, increased energy consumption, and frequent maintenance. Summary of the Invention

[0004] The purpose of this invention is to provide a preheating device for wastewater treatment, so as to solve the problem mentioned in the background art that the prior art cannot automatically start the descaling mechanism according to the flow rate.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A preheating device for wastewater treatment includes a preheating pipe with a Venturi throat integrally formed at its middle position. Pressure tapping pipes are fixedly connected to the circumferential surfaces of both the preheating pipe and the Venturi throat. A piston tube is fixedly connected to the adjacent ends of the two pressure tapping pipes. A piston plate is slidably connected inside the piston tube, and a moving groove is formed on the circumferential surface of the piston tube. A motor is fixedly connected to one end of the piston tube, and a telescopic rod is fixedly connected to the output end of the motor. A moving block is fixedly connected to the circumferential surface of the piston plate, and the moving block is rotatably connected to the circumferential surface of the telescopic rod. Elastic folding plates are fixedly connected between the inner walls of both sides of the moving groove and the two ends of the moving block. A drive shaft is rotatably connected to the circumferential surface of the piston tube, and a first friction plate and a second friction plate are fixedly connected to the adjacent ends of the drive shaft and the telescopic rod, respectively.

[0007] Furthermore, a mounting shell is fixedly connected to the circumferential surface of the preheating tube, and a lead screw is rotatably connected between the inner walls of the two sides of the mounting shell. I-beams are fixedly connected to the circumferential surfaces of the drive shaft and the lead screw. A drive belt is drivingly connected to the circumferential surfaces of the two I-beams. A lead screw nut is threadedly connected to the circumferential surface of the lead screw. A powerful magnetic ring is fixedly connected to one end of the lead screw nut. The powerful magnetic ring is sleeved on the circumferential surface of the preheating tube. An adsorbed magnetic ring is slidably connected inside the preheating tube. A rotating ring is slidably connected to the inner circumferential wall of the adsorbed magnetic ring. Multiple scrapers are fixedly connected to the circumferential surface of the rotating ring. The adsorbed magnetic ring is magnetically connected to the powerful magnetic ring.

[0008] Furthermore, the inner circumferential wall of the preheating tube is provided with a thread, and a plurality of first permanent magnets are embedded in the inner wall of the thread. The polarities of the plurality of first permanent magnets are arranged alternately as N, S, N, S along the thread. A plurality of second permanent magnets are distributed at the outer edge of the plurality of scrapers. The polarities of the plurality of second permanent magnets are arranged alternately as N, S, N, S between adjacent scrapers. The plurality of scrapers and the plurality of second permanent magnets are arranged with a circumferential pitch, and the pitch of the plurality of second permanent magnets and the plurality of first permanent magnets are equal.

[0009] Furthermore, a movable shell is fixedly connected to the circumferential surface of the preheating tube, and a striking plate is slidably connected inside the movable shell. A cam is fixedly connected to the circumferential surface of the drive shaft, and the cam abuts against the striking plate.

[0010] Furthermore, limiting grooves are provided on both inner walls of the movable shell, and vertical blocks are fixedly connected to both ends of the striking plate. The two vertical blocks are slidably connected in the two limiting grooves, and springs are fixedly connected between the upper inner walls of the two limiting grooves and the upper ends of the vertical blocks.

[0011] Furthermore, a stabilizing groove is provided inside the movable block, and a pulling block is fixedly connected to the circumferential surface of the telescopic rod, with the pulling block rotatably connected inside the stabilizing groove.

[0012] Furthermore, two horizontal grooves are formed on the inner circumference of the piston tube, and two horizontal blocks are fixedly connected to the circumferential surface of the piston plate, with the two horizontal blocks slidably connected in the two horizontal grooves respectively.

[0013] Furthermore, the inner circumference of the magnetic ring being attracted is provided with a driving groove, and a driving ring is fixedly connected to the circumferential surface of the rotating ring, the driving ring being rotatably connected to the driving groove.

[0014] Furthermore, the first friction plate and the second friction plate are both provided with reinforcing fibers and friction particles at their close ends.

[0015] Furthermore, a filter screen is fixedly connected to the inner circumference of both pressure tapping tubes.

[0016] The technical solution provided by this invention has the following advantages compared with the known prior art:

[0017] 1. Wastewater, heated by the preheating pipe, enters the venturi throat, where the flow velocity increases dramatically and the static pressure is lowest, creating a stable static pressure difference with the left preheating pipe. This difference is introduced to both ends of the piston pipe through the pressure tapping pipe. During normal high flow rates, the static pressure on the left is greater than on the right, pushing the piston plate to the right. After scaling on the preheating pipe, the flow velocity decreases, the pressure difference between the left and right sides narrows, and the piston plate gradually returns to its original position to the left, causing the telescopic rod to engage the second friction plate with the first friction plate. Motor power is then transmitted via the drive shaft, drive belt, and lead screw, driving the powerful magnetic ring to move axially. The powerful magnetic ring uses magnetic attraction to move the internal attracted magnetic ring, rotating ring, and scraper forward together, scraping away the scale on the pipe wall. As the scraper moves axially, its N and S magnetic poles periodically misalign and realign with the spiral magnetic poles on the pipe wall. To avoid like-pole repulsion and restore the steady state of unlike-pole attraction, the scraper is forced to rotate continuously in the circumferential direction, thus generating rotational motion while cleaning the scale axially, improving cleaning efficiency.

[0018] Second, when the drive shaft rotates, it can drive the cam to rotate. When the cam rotates, it will periodically abut against the striking plate, causing the striking plate to move upward and hit the circumferential surface of the preheating tube, causing the preheating tube to vibrate. Through vibration, the scale and the adhesion of the inner wall of the preheating tube are reduced, improving the descaling effect and speed. When the striking plate moves up and down, it can simultaneously drive the two vertical blocks to move in the two limit grooves respectively, improving the vertical movement stability of the striking plate. Two springs can assist the vertical blocks to descend quickly, facilitating the rapid reset of the striking plate. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0020] Figure 1 This is a front perspective view of the present invention;

[0021] Figure 2 For the present invention Figure 1 A magnified view of a section at point A in the middle;

[0022] Figure 3 This is a perspective view of the main cross-section of the present invention;

[0023] Figure 4 For the present invention Figure 3 A magnified view of a section at point B in the middle;

[0024] Figure 5 For the present invention Figure 3 A magnified view of a section at point C;

[0025] Figure 6 This is a first side sectional perspective view of the present invention;

[0026] Figure 7 For the present invention Figure 6 A magnified view of a section at point D.

[0027] Figure 8 This is a second side sectional perspective view of the present invention.

[0028] In the diagram: 1. Preheating pipe; 101. Venturi tube throat; 102. Pressure tapping pipe; 103. Piston tube; 104. Piston plate; 105. Horizontal groove; 106. Moving groove; 107. Elastic folding plate; 108. Moving block; 109. Motor; 110. Telescopic rod; 111. Drive shaft; 112. First friction plate; 113. Second friction plate; 114. Pulling block; 2. Cam; 201. Movable shell; 202. Striking plate; 203. Vertical block; 204. Spring; 3. I-beam wheel; 301. Drive belt; 302. Mounting shell; 303. Lead screw; 304. Limiting rod; 305. Lead screw nut; 306. Strong magnetic ring; 307. Adsorbed magnetic ring; 308. Driving ring; 309. Rotating ring; 310. Scraper; 311. Threaded wire. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0030] The present invention will be further described below with reference to embodiments.

[0031] Example: A preheating device for wastewater treatment, such as Figures 1-8As shown, the device includes a preheating pipe 1, with a Venturi throat 101 integrally formed in the middle. When fluid passes through the Venturi throat 101, the flow rate can be increased by passing through a narrower channel. Pressure taps 102 are fixedly connected to the circumferential surfaces of both the preheating pipe 1 and the Venturi throat 101. A piston tube 103 is fixedly connected to the near ends of the two pressure taps 102. A piston plate 104 is slidably connected inside the piston tube 103. The piston plate 104 can synchronously sense the flow rate in the preheating pipe 1, maintaining a stable position when the flow rate is normal and moving to the left when the flow rate is low. A moving groove 106 is formed on the circumferential surface of the piston tube 103. A motor 109 is fixedly connected to one end of the piston tube 103. The motor 109 outputs... A telescopic rod 110 is fixedly connected to the outlet end. A moving block 108 is fixedly connected to the circumferential surface of the piston plate 104. The moving block 108 is rotatably connected to the circumferential surface of the telescopic rod 110. Elastic folding plates 107 are fixedly connected between the inner walls of both sides of the moving groove 106 and the two ends of the moving block 108. The elastic folding plate 107 has a certain elastic potential energy. When the flow rate in the preheating pipe 1 is insufficient, the elastic folding plate 107 can pull back the piston plate 104. The elastic folding plate 107 can also prevent liquid leakage in the piston tube 103. A drive shaft 111 is rotatably connected to the circumferential surface of the piston tube 103. A first friction plate 112 and a second friction plate 113 are fixedly connected to the close ends of the drive shaft 111 and the telescopic rod 110, respectively.

[0032] A mounting shell 302 is fixedly connected to the circumferential surface of the preheating pipe 1. The mounting shell 302 protects the internal components. A lead screw 303 is rotatably connected between the inner walls of the two sides of the mounting shell 302. I-beam wheels 3 are fixedly connected to the circumferential surfaces of both the drive shaft 111 and the lead screw 303. A drive belt 301 is drivenly connected to the circumferential surfaces of the two I-beam wheels 3. The power of the drive shaft 111 can be transmitted to the lead screw 303 through the drive belt 301 and the two I-beam wheels 3. A screw nut 305 is threaded onto the circumferential surface of rod 303. A strong magnetic ring 306 is fixedly connected to one end of screw nut 305. The strong magnetic ring 306 is sleeved on the circumferential surface of preheating tube 1. An adsorbed magnetic ring 307 is slidably connected inside preheating tube 1. A rotating ring 309 is slidably connected to the inner circumferential wall of the adsorbed magnetic ring 307. Multiple scrapers 310 are fixedly connected to the circumferential surface of rotating ring 309. The adsorbed magnetic ring 307 is magnetically connected to the strong magnetic ring 306.

[0033] The preheating pipe 1 has a threaded line 311 on its inner circumference. Multiple first permanent magnets are embedded in the inner wall of the threaded line 311. The polarities of the multiple first permanent magnets are arranged alternately as N, S, N, S along the threaded line 311. Multiple second permanent magnets are distributed at the outer edge of multiple scrapers 310. The polarities of the multiple second permanent magnets are arranged alternately as N, S, N, S between adjacent scrapers 310. The multiple scrapers 310 and the multiple second permanent magnets are arranged with a circumferential pitch. The pitch of the multiple second permanent magnets is equal to that of the multiple first permanent magnets.

[0034] In a specific embodiment of the present invention, when the wastewater passes through the preheating pipe 1 and the venturi throat 101, the wastewater is preheated by the heating function of the preheating pipe 1. When the fluid passes through the venturi throat 101, its flow rate is forced to increase and the static pressure is the lowest. Therefore, a stable static pressure difference is formed between the preheating pipe 1 on the left and the venturi throat 101. The two pressure tapping pipes 102 introduce the pressure difference into the piston tube 103. Under normal conditions, the flow rate is low and the static pressure is high at the left end of the venturi throat 101, while the flow rate is high and the static pressure is low inside the venturi throat 101. This causes the static pressure on the left side of the piston tube 103 to be greater than the static pressure on the right side. The piston plate 104 will be pushed to the right by the side with greater pressure on the left. After a certain amount of scaling is generated in the preheating pipe 1, the flow rate of the wastewater inside it will also decrease accordingly. Therefore, the static pressure will also decrease. At this time, the pressure difference between the left and right sides of the piston tube 103 will gradually decrease.

[0035] As the pressure difference between the left and right sides of the piston tube 103 gradually decreases, the piston plate 104 will gradually move to the left and pull the telescopic end of the telescopic rod 110 to move synchronously, thereby driving the second friction plate 113 to contact the first friction plate 112. At this time, the power generated by the rotation of the output shaft of the motor 109 can be transmitted to the first friction plate 112 and the transmission shaft 111 through the second friction plate 113 of the telescopic rod 110. Then, the power is transmitted to the lead screw 303 through the transmission belt 301 and the two I-beam pulleys 3. When the lead screw 303 rotates, it synchronously drives the lead screw nut 305 and the strong magnetic ring 306 to move. The strong magnetic ring 306 has strong magnetism and can attract the magnetic ring 307. When the magnetic ring 307 moves with the strong magnetic ring 306, it can synchronously drive the rotating ring 309 and multiple scrapers 310 to move. The multiple scrapers 310 can clean the scale accumulated on the inner circumference of the preheating tube 1.

[0036] When the scraper 310 moves axially, if it only translates, the corresponding N and N magnetic pole pairs will be misaligned. For example, after moving half a pitch, the N pole will be aligned with the opposite N pole. Since the like poles NN or SS generate a strong repulsive force, and the magnetic poles are arranged alternately in the circumferential direction, in order to avoid this maximum repulsive force and return to the stable state of NS attraction, the second permanent magnet on the scraper 310 has to move in the circumferential direction, i.e. the direction of rotation, to find the next nearest opposite magnetic pole. Because the scraper 310 is continuously pushed in the axial direction, the magnetic pole pairs will continuously experience the cycle of "stable NS → misaligned NN repulsion → rotation to find a new NS → stable again". This continuous circumferential positioning action forces the scraper 310 to continuously rotate around its own axis while moving axially. Through the rotation of multiple scrapers 310, the efficiency and thoroughness of scraping the inside of the preheating tube 1 can be improved.

[0037] Preferably, the mechanisms on the lower and left sides of the Venturi throat 101 can be symmetrically arranged along the center of the preheating tube 1, that is, scale is provided on both sides of the preheating tube 1, which facilitates the thorough scraping of scale inside the preheating tube 1.

[0038] Please refer to the details. Figure 1-8 A movable shell 201 is fixedly connected to the circumferential surface of the preheating pipe 1, and a striking plate 202 is slidably connected inside the movable shell 201. A cam 2 is fixedly connected to the circumferential surface of the drive shaft 111, and the cam 2 and the striking plate 202 abut against each other.

[0039] Limiting grooves are provided on both inner walls of the movable shell 201. Vertical blocks 203 are fixedly connected to both ends of the striking plate 202. The two vertical blocks 203 are slidably connected in the two limiting grooves respectively. Springs 204 are fixedly connected between the upper inner walls of the two limiting grooves and the upper ends of the vertical blocks 203.

[0040] In this embodiment: when the drive shaft 111 rotates, it can drive the cam 2 to rotate. When the cam 2 rotates, it will periodically abut against the striking plate 202, causing the striking plate 202 to move upward and strike the circumferential surface of the preheating tube 1, causing the preheating tube 1 to vibrate. The vibration reduces the adhesion of scale and the inner wall of the preheating tube 1, improving the descaling effect and speed. When the striking plate 202 moves up and down, it can simultaneously drive the two vertical blocks 203 to move in the two limiting grooves respectively, improving the vertical movement stability of the striking plate 202. The two springs 204 can assist the vertical blocks 203 to descend quickly, making it convenient for the striking plate 202 to quickly reset.

[0041] Please refer to the details. Figure 1-8 A stabilizing groove is provided inside the movable block 108, and a pulling block 114 is fixedly connected to the circumferential surface of the telescopic rod 110. The pulling block 114 is rotatably connected to the stabilizing groove.

[0042] Two horizontal grooves 105 are formed on the inner circumference of the piston tube 103, and two horizontal blocks are fixedly connected to the circumferential surface of the piston plate 104. The two horizontal blocks are slidably connected in the two horizontal grooves 105 respectively.

[0043] In this embodiment: when the moving block 108 drives the telescopic rod 110 to move, the pulling block 114 and the telescopic rod 110 can be pulled by the stabilizing groove. Without hindering the rotation of the telescopic rod 110, the telescopic rod 110 can be extended and retracted. When the piston plate 104 moves, the two horizontal blocks can be moved synchronously in the two horizontal grooves 105, thereby improving the horizontal movement stability of the piston plate 104.

[0044] Please refer to the details. Figure 1-8 The magnetic ring 307 being attracted has a drive groove on its inner circumference, and the rotating ring 309 has a drive ring 308 fixedly connected to its circumference surface. The drive ring 308 is rotatably connected to the drive groove.

[0045] The first friction plate 112 and the second friction plate 113 are both provided with reinforcing fibers and friction particles at their close ends.

[0046] Both pressure tapping tubes 102 have filter screens fixedly connected to their inner circumferences.

[0047] In this embodiment: when the adsorbed magnetic ring 307 moves, the rotating ring 309 can be moved by the cooperation of the drive groove and the drive ring 308. It can also move the rotating ring 309 without affecting its rotation. The connecting friction force of the first friction plate 112 and the second friction plate 113 can be improved by reinforcing fibers and friction particles, thereby improving the power transmission. The filter screen can prevent wastewater particles in the preheating pipe 1 from entering the pressure tapping pipe 102 and the piston pipe 103 and causing blockage.

[0048] Preferably, a limiting rod 304 is fixedly connected between the inner walls of the two sides of the mounting shell 302, and a hole is opened at one end of the lead screw nut 305 to cooperate with the limiting rod 304. When the lead screw nut 305 moves, it can slide on the circumferential surface of the limiting rod 304 through the hole to prevent the lead screw nut 305 from rotating.

[0049] Preferably, the moving groove 106 extends axially along the piston tube 103, and the inner walls at both ends of the moving groove 106 form limiting surfaces. When the piston plate 104 drives the moving block 108 to the limit position of the stroke, the corresponding end face of the moving block 108 abuts against the end wall of the moving groove 106 to limit the continued movement of the piston plate 104, thereby preventing the elastic folding plate 107 from undergoing plastic deformation or damage due to exceeding the deformation range;

[0050] Preferably, the axial length of the moving groove 106 is less than the unfolded length of the elastic folding plate 107 in its natural state, and the stroke range of the moving block 108 is limited between the two end walls of the moving groove 106. When the piston plate 104 is in any working position, the elastic folding plate 107 is in a compressed or stretched state before reaching its elastic limit. By constraining the deformation of the elastic folding plate 107 within the stroke range of the moving block 108, the elastic folding plate 107 remains within its elastic deformation zone throughout the entire working process, thereby delaying the occurrence of elastic fatigue.

[0051] Preferably, the two ends of the elastic folding plate 107 are fixedly connected to the inner wall of the moving groove 106 and the end face of the moving block 108, respectively. When it is necessary to replace the elastic folding plate 107, the piston tube 103 is removed from the two pressure tapping tubes 102, or the piston plate 104 together with the moving block 108 is pulled out axially from the end opening of the piston tube 103, so that the fixed connection at both ends of the elastic folding plate 107 can be released and it can be replaced.

[0052] Working principle: When wastewater passes through the preheating pipe 1 and the venturi throat 101, the wastewater is preheated by the heating function of the preheating pipe 1. When the fluid passes through the venturi throat 101, its flow rate is forced to increase and the static pressure is at its lowest. Therefore, a stable static pressure difference is formed between the preheating pipe 1 on the left and the venturi throat 101. The two pressure taps 102 introduce the pressure difference into the piston tube 103. Under normal conditions, because the flow rate is low and the static pressure is high at the left end of the venturi throat 101, while the flow rate is high and the static pressure is low inside the venturi throat 101, the static pressure on the left side of the piston tube 103 is greater than that on the right side. The piston plate 104 will be pushed to the right by the side with higher pressure on the left. After a certain amount of scaling is generated in the preheating pipe 1, the flow rate of the wastewater inside it will also decrease accordingly, so the static pressure will also decrease. At this time, the pressure difference between the left and right sides of the piston tube 103 will gradually decrease.

[0053] As the pressure difference between the left and right sides of the piston tube 103 gradually decreases, the piston plate 104 will gradually move to the left and pull the telescopic end of the telescopic rod 110 to move synchronously, thereby driving the second friction plate 113 to contact the first friction plate 112. At this time, the power generated by the rotation of the output shaft of the motor 109 can be transmitted to the first friction plate 112 and the transmission shaft 111 through the second friction plate 113 of the telescopic rod 110. Then, the power is transmitted to the lead screw 303 through the transmission belt 301 and the two I-beam pulleys 3. When the lead screw 303 rotates, it synchronously drives the lead screw nut 305 and the strong magnetic ring 306 to move. The strong magnetic ring 306 has strong magnetism and can attract the magnetic ring 307. When the magnetic ring 307 moves with the strong magnetic ring 306, it can synchronously drive the rotating ring 309 and multiple scrapers 310 to move. The multiple scrapers 310 can clean the scale accumulated on the inner circumference of the preheating tube 1.

[0054] When the scraper 310 moves axially, if it only translates, the corresponding N and N magnetic pole pairs will be misaligned. For example, after moving half a pitch, the N pole will be aligned with the opposite N pole. Since the like poles NN or SS generate a strong repulsive force, and the magnetic poles are arranged alternately in the circumferential direction, in order to avoid this maximum repulsive force and return to the stable state of NS attraction, the second permanent magnet on the scraper 310 has to move in the circumferential direction, i.e. the direction of rotation, to find the next nearest opposite magnetic pole. Because the scraper 310 is continuously pushed in the axial direction, the magnetic pole pairs will continuously experience the cycle of "stable NS → misaligned NN repulsion → rotation to find a new NS → stable again". This continuous circumferential positioning action forces the scraper 310 to continuously rotate around its own axis while moving axially. Through the rotation of multiple scrapers 310, the efficiency and thoroughness of scraping the inside of the preheating tube 1 can be improved.

[0055] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. A preheating device for wastewater treatment, comprising a preheating pipe (1), characterized in that: A Venturi tube throat (101) is integrally formed at the middle position of the preheating tube (1). Pressure tapping tubes (102) are fixedly connected to the circumferential surfaces of both the preheating tube (1) and the Venturi tube throat (101). A piston tube (103) is fixedly connected to the near ends of the two pressure tapping tubes (102). A piston plate (104) is slidably connected inside the piston tube (103), and a moving groove (106) is opened on the circumferential surface of the piston tube (103). A motor (109) is fixedly connected to one end of the piston tube (103), and the output end of the motor (109) is fixedly connected to... The piston plate (104) has a telescopic rod (110), and a moving block (108) is fixedly connected to the circumferential surface of the piston plate (104). The moving block (108) is rotatably connected to the circumferential surface of the telescopic rod (110). An elastic folding plate (107) is fixedly connected between the inner walls of both sides of the moving groove (106) and the two ends of the moving block (108). A transmission shaft (111) is rotatably connected to the circumferential surface of the piston tube (103). A first friction plate (112) and a second friction plate (113) are fixedly connected to the adjacent ends of the transmission shaft (111) and the telescopic rod (110), respectively.

2. The preheating device for wastewater treatment according to claim 1, characterized in that: A mounting shell (302) is fixedly connected to the circumferential surface of the preheating pipe (1). A lead screw (303) is rotatably connected between the inner walls of the two sides of the mounting shell (302). I-beam wheels (3) are fixedly connected to the circumferential surfaces of the drive shaft (111) and the lead screw (303). A drive belt (301) is drivingly connected to the circumferential surfaces of the two I-beam wheels (3). A lead screw nut (305) is threadedly connected to the circumferential surface of the lead screw (303). One end of the preheating tube (1) is fixedly connected to a strong magnetic ring (306). The strong magnetic ring (306) is sleeved on the circumferential surface of the preheating tube (1). A magnetic ring (307) is slidably connected inside the preheating tube (1). A rotating ring (309) is slidably connected to the inner circumferential wall of the magnetic ring (307). A plurality of scrapers (310) are fixedly connected to the circumferential surface of the rotating ring (309). The magnetic ring (307) is magnetically connected to the strong magnetic ring (306).

3. The preheating device for wastewater treatment according to claim 2, characterized in that: The preheating pipe (1) has a threaded line (311) on its inner circumference. Multiple first permanent magnets are embedded in the inner wall of the threaded line (311). The polarities of the multiple first permanent magnets are arranged alternately as N, S, N, S along the threaded line (311). Multiple second permanent magnets are distributed at the outer edge of the multiple scrapers (310). The polarities of the multiple second permanent magnets are arranged alternately as N, S, N, S between adjacent scrapers. The multiple scrapers (310) and the multiple second permanent magnets are arranged with a circumferential pitch. The pitch of the multiple second permanent magnets and the multiple first permanent magnets are equal.

4. A preheating device for wastewater treatment according to claim 3, characterized in that: The preheating pipe (1) has a movable shell (201) fixedly connected to its circumferential surface. A striking plate (202) is slidably connected inside the movable shell (201). A cam (2) is fixedly connected to the circumferential surface of the transmission shaft (111). The cam (2) and the striking plate (202) abut against each other.

5. A preheating device for wastewater treatment according to claim 4, characterized in that: Limiting grooves are provided on both sides of the inner wall of the movable shell (201). Vertical blocks (203) are fixedly connected to both ends of the striking plate (202). The two vertical blocks (203) are slidably connected in the two limiting grooves respectively. A spring (204) is fixedly connected between the upper inner wall of the two limiting grooves and the upper end of the vertical block (203).

6. A preheating device for wastewater treatment according to claim 5, characterized in that: The movable block (108) has a stabilizing groove, and the circumferential surface of the telescopic rod (110) is fixedly connected to a pulling block (114), which is rotatably connected to the stabilizing groove.

7. A preheating device for wastewater treatment according to claim 6, characterized in that: The piston tube (103) has two horizontal grooves (105) on its inner circumference. The piston plate (104) has two horizontal blocks fixedly connected to its circumference surface. The two horizontal blocks are slidably connected in the two horizontal grooves (105).

8. A preheating device for wastewater treatment according to claim 7, characterized in that: The magnetic ring (307) being attracted has a drive groove on its inner circumference, and the rotating ring (309) has a drive ring (308) fixedly connected to its circumference surface. The drive ring (308) is rotatably connected to the drive groove.

9. A preheating device for wastewater treatment according to claim 8, characterized in that: The first friction plate (112) and the second friction plate (113) are provided with reinforcing fibers and friction particles at their close ends.

10. A preheating device for wastewater treatment according to claim 9, characterized in that: Both pressure taps (102) have filter screens fixedly connected to their inner circumferential walls.

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