A device and method for continuously measuring the thickness of sludge in a sewage tank

Abstract

This invention discloses a continuous measuring device and method for measuring the thickness of sludge and oil in a sewage tank, belonging to the field of measurement technology. It includes a sleeve, a measuring unit, and a display unit. The sleeve is a hollow cylindrical structure with openings at both ends. The measuring unit is installed above the central channel of the sleeve and includes a water float and an oil float that enter the sleeve and contact the sewage surface and the sludge and oil surface respectively. Each float is connected to a pull rope that passes over a fixed pulley. The other ends of the two pull ropes are connected to two indicator dials reflecting the difference in water and oil levels. The display unit is located outside the measuring unit and includes a transparent outer cylinder and a scale inside it. The two indicator dials are located at the front of the scale, which directly displays the difference in liquid levels between the two dials. This invention eliminates the risks associated with existing sludge and oil thickness measurement processes and enables real-time display of both sewage level and sludge and oil thickness parameters.

Description

Technical Field

[0001] This invention relates to the field of measurement technology, specifically to a device and method for continuously measuring the thickness of sludge and oil in a sewage tank. Background Technology

[0002] In chemical production units such as oil and gas processing plants, wastewater and oily sludge are discharged into maintenance wastewater tanks during equipment discharge or maintenance, forming a two-layer structure of wastewater at the bottom and oily sludge on top. Because the amounts of wastewater and oily sludge differ, and because they belong to different national hazardous waste lists, they must be transported separately. Specifically, wastewater is pumped out when it reaches a certain depth, and oily sludge is dredged out when it reaches a certain thickness. Most existing wastewater tank level measurement instruments use pressure level gauges. When the liquid level exceeds the probe, the pressure generated by the liquid height is measured and converted into wastewater depth. This measurement value represents the overall depth of the wastewater tank and cannot reflect the actual thickness of the oily sludge. The current method for measuring the thickness of oil sludge involves periodically using a dipstick. This involves applying a testing paste to a portion of the dipstick, immersing the paste-coated dipstick in the oil sludge, and allowing sufficient time for the paste and oil to react chemically. The length of the discolored area on the dipstick represents the thickness of the oil sludge. However, this method has the following drawbacks: (1) During the measurement process, the test oil paste is consumed, and dirt is generated when cleaning the oil paste on the measuring tape; (2) The measurement steps are cumbersome; (3) It cannot continuously measure the thickness of the sludge; (4) Since the sewage tank area is a flammable and explosive place, the sewage tank is in a semi-enclosed state. Every time the dipstick is used, the manhole pressure plate needs to be moved. Not only is there a possibility of crushing fingers and generating sparks, but the flammable gas released from the sewage tank will also inevitably overflow, which will bring certain safety risks to the measurement personnel.

[0003] There are also some patents in the existing technology for measuring the thickness of oil, such as the photoelectric composite wireless sensing method and device for measuring the thickness of petroleum hydrocarbon pollutants in water disclosed in patent CN106524930A. However, the implementation of such patent solutions mostly requires the use of electrically powered testing instruments, which cannot be applied to places without power connection.

[0004] Therefore, this solution proposes a purely mechanical device suitable for flammable and explosive environments, which does not require opening manholes and can continuously measure the thickness of sludge oil, in order to eliminate the aforementioned hidden dangers in the prior art. Summary of the Invention

[0005] In response to the environmental characteristics of sewage ponds and the shortcomings of existing sludge and oil measurement, this invention proposes a device that can eliminate the risks of the measurement process, consume no materials, and continuously measure the thickness of sludge and oil. The device is composed of a surge protection sleeve, a measurement unit, and a display unit, which eliminates the risks of existing sludge and oil thickness measurement processes and can realize real-time display of two parameters: sewage level and sludge and oil thickness.

[0006] To achieve the above-mentioned objectives, the technical solution of the present invention is as follows: This invention proposes a continuous measuring device for the thickness of sludge and oil in a sewage tank, comprising a sleeve, a measuring unit, and a display unit. The sleeve is a hollow cylindrical structure with openings at both the top and bottom. The measuring unit is installed above the central channel of the sleeve and includes a water float and an oil float that enter the sleeve and contact the sewage surface and the sludge and oil surface, respectively. The two floats are each connected to a pull rope that passes around a fixed pulley, and the other ends of the two pull ropes are respectively connected to two indicator dials that reflect the difference in water and oil levels. The display unit is mounted on the outside of the measuring unit and includes a transparent outer cylinder and a scale set inside it. The two indicator dials are located at the front end of the scale, and the scale directly displays the difference in liquid levels between the two indicator dials.

[0007] Furthermore, the area of ​​the sleeve that comes into contact with the liquid in the sewage tank is provided with a surge protection structure.

[0008] Furthermore, the surge protection structure includes a through hole on the outer wall of the sleeve that contacts the liquid in the sewage tank, and a full-hole isolation plate vertically installed at the center of the sleeve.

[0009] Furthermore, a ring-shaped fixing plate is provided around the opening at the top of the sleeve, and a connecting rod for connecting the measuring unit is provided on the ring-shaped fixing plate.

[0010] Furthermore, the fixed pulley is fixed on the truss, and the two ends of the truss are connected to connecting rods, and connecting tubes are connected to the connecting rods. The truss is connected and fixed to the connecting rod set at the top of the sleeve through the connecting tubes.

[0011] Furthermore, the other ends of the two ropes are each connected to a counterweight for balancing the weight.

[0012] Furthermore, the transparent sleeve is a semi-closed structure with an open bottom and a sealed top, and its bottom is upside down on the annular fixing plate to form a closed connection with it.

[0013] Furthermore, the transparent outer cylinder is made of acrylic material.

[0014] This invention also proposes a method for continuously measuring the thickness of sludge and oil in a sewage tank, comprising the following steps: Step 1: Fix the hollow sleeve to the opening of the cement cover plate of the manhole of the sewage tank through the annular fixing plate set on its top, and immerse the bottom of the sleeve into the sewage tank. Step 2: The truss of the measuring unit is fixedly connected to the top of the sleeve through the connecting tube and the connecting rod. Two fixed pulleys are set on the truss. The water float and oil float are lowered to both sides of the full-hole isolation plate inside the sleeve, respectively, to contact the sewage liquid surface and the oily liquid surface. The two floats are each connected to a pull rope that goes around the fixed pulley. The other end of the two pull ropes is connected to an indicator plate. The height difference between the two indicator plates can reflect the water and oil level difference. At the same time, the other end of the two pull ropes is connected to a counterweight for balancing the mass of the pull ropes. Step 3: The semi-enclosed transparent outer cylinder of the display unit is inverted onto the annular fixing plate at the top of the sleeve to form a closed connection. The liquid level difference between the two indicator dials is read by a ruler to obtain the oil thickness.

[0015] Furthermore, during the implementation of step one, since it is not easy to drill holes in the reinforced concrete structure of the sewage tank, two semi-circular cement manhole covers are made using the location of the manhole cover. A hole is drilled in one of the semi-circular cement manhole covers to fix the surge protection sleeve of the continuous sludge thickness measuring device; the other semi-circular manhole cover retains its original function.

[0016] In summary, the present invention has the following advantages: (1) In the measuring device proposed in this invention, the surge protection sleeve can prevent the measurement from being disturbed by changes in sewage level; the measuring unit adopts a combination of double floats. Taking advantage of the different densities of oil and water, floats suitable for different densities are customized. Through simple accessories such as pull ropes, fixed pulleys, and indicator plates, the liquid level parameters of different liquids are integrated into the same display system, which can realize the real-time display of two parameters: sewage level and sludge thickness. It is simple and effective. (2) The measuring device proposed in this invention has a simple overall structure and is easy to manufacture, install and disassemble. It has low measurement cost. The measuring device uses pure mechanical components, has high reliability and zero consumption and zero energy consumption. It is particularly suitable for places that are flammable, explosive, toxic and harmful and have no power connection. (3) The measurement method proposed in this invention is simple to operate, can realize continuous measurement of oil thickness, and does not require opening the manhole, thus avoiding the safety risks in the manual measurement process; (4) The measuring device proposed in this invention is completely sealed, which isolates the medium overflow channel in the sewage tank and meets the explosion-proof requirements; (5) In the measuring device proposed in this invention, the other ends of the two pull ropes are respectively connected to counterweights for balancing the weight, so as to improve the measurement sensitivity. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the surge protection sleeve of the present invention. Figure 2 This is a schematic diagram of the structural principle of the measuring unit of the present invention; Figure 3This is a schematic diagram of the display unit of the present invention; In the picture: 101. Sleeve; 102. Annular fixing plate; 103. Connecting rod; 104. Isolation plate; 105. Through hole; 201. Truss; 202. Fixed pulley; 203. Pull rope; 204. Connecting cylinder; 205. Connecting rod; 206. Counterweight; 207. Indicator dial; 208. Water float; 209. Oil float; 301. Transparent outer cylinder; 302. Ruler. Detailed Implementation

[0018] 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 embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0021] In the description of this invention, it should be noted that the terms "upper," "vertical," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0022] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0023] Example 1 This invention proposes a continuous measuring device for the thickness of sludge and oil in a sewage tank, comprising a surge protector sleeve 101, a measuring unit, and a display unit. The surge protector sleeve 101 is a hollow cylindrical structure with openings at both the top and bottom. The measuring unit is installed above the central channel of the sleeve 101 and includes a water float 208 and an oil float 209 that enter the sleeve 101 and contact the sewage surface and the sludge and oil surface, respectively. The two floats are each connected to a pull rope 203 that passes around a fixed pulley 202. The other ends of the two pull ropes 203 are connected to two indicator discs 207 that reflect the difference in water and oil levels. The display unit is mounted on the outside of the measuring unit and includes a transparent outer cylinder 301 and a scale 302 disposed inside it. The two indicator discs 207 are located at the front end of the scale 302, and the scale 302 directly displays the difference in liquid levels between the two indicator discs 207.

[0024] In use, the lower end of the surge protector sleeve 101 is immersed in the sewage tank, so that the two floats of the measuring unit float on the sewage surface and the oily surface respectively. The two indicator discs 207 connected to the other end of the pull rope 203 can reflect the current difference between the oil and water levels, i.e. the thickness of the oily liquid. The display unit can easily read the current sewage level and the oily liquid thickness value.

[0025] The measuring device proposed in this solution has a simple overall structure and is easy to manufacture, install, and disassemble, resulting in low measurement costs. The surge protector 101 ensures that measurements are unaffected by changes in sewage level. The measuring unit employs a dual-float combination, utilizing the different densities of oil and water to customize floats suitable for different densities. Through simple accessories such as a pull rope 203, a fixed pulley 202, and an indicator panel 207, the liquid level parameters of different liquids are integrated into the same display system, enabling real-time display of both sewage level and oily sludge thickness—a simple and effective solution.

[0026] Example 2 This invention proposes a continuous measuring device for the thickness of sludge and oil in a sewage tank, comprising a sleeve 101, a measuring unit, and a display unit.

[0027] like Figure 1 The diagram shows the structural principle of the sleeve 101 in this invention. The sleeve 101 is a hollow cylindrical structure with openings at both the top and bottom. A ring-shaped fixing plate 102 is arranged around the opening at the top of the sleeve 101, and a connecting rod 103 for connecting the measuring unit is provided on the ring-shaped fixing plate 102. In use, the sleeve 101 is fixed to the cement cover plate of the manhole of the sewage tank (with a separate hole on the cover plate) through the ring-shaped fixing plate 102, and the bottom of the sleeve 101 is immersed in the sewage tank.

[0028] Furthermore, to reduce the impact of liquid level fluctuations during sewage discharge on the liquid level display, a surge protection structure is provided on the sleeve 101. Specifically, the surge protection structure includes a through hole 105 on the outer wall of the sleeve 101 where it contacts the liquid in the sewage tank, and a fully perforated isolation plate 104 vertically positioned at the center of the sleeve 101. The through hole 105 on the outer wall of the sleeve ensures that the liquid levels inside and outside the sleeve 101 are consistent, while the fully perforated isolation plate 104 prevents both surges and entanglement of the float and pull rope 203 of the measuring unit.

[0029] The measuring unit is mounted above the sleeve 101, and its structure is as follows: Figure 2 As shown. The measuring unit includes a water float 208 and an oil float 209 that pass through the central channel of the sleeve 101 and are in contact with the sewage surface and the oily surface, respectively. Because the two floats have different densities, the water float 208 is suitable for the sewage density and can only float on the sewage surface; the oil float 209 is suitable for the oily density and floats on the oily surface. Each of these floats is connected to a pull rope 203 (both pull ropes 203 are of the same length) that passes over a fixed pulley 202. The other ends of the two pull ropes 203 are respectively connected to an indicator dial 207. The height difference between the two indicator dials 207 reflects the water-oil level difference.

[0030] Furthermore, the other ends of the two ropes 203 are respectively connected to counterweights 206 for balancing the weight, in order to improve the measurement sensitivity.

[0031] Specifically, in this invention, the fixed pulley 202 is fixed on the truss 201, and the two ends of the truss 201 are provided with connecting rods 205, and connecting tubes 204 are connected to the connecting rods 205. The truss 201 is assembled and fixed with the connecting rod 103 provided on the top of the sleeve 101 through the connecting tubes 204.

[0032] like Figure 3 The diagram shows the structure of the display unit, which includes a transparent outer cylinder 301 and a scale 302 disposed inside it.

[0033] The transparent outer cylinder 301 is installed outside the measuring unit and is a semi-enclosed structure with an open bottom and a sealed top. Its bottom is inverted and fixed to the annular fixing plate 102, sealing the measuring device and thus isolating the overflow channel of the medium in the sewage tank, meeting explosion-proof requirements. The two indicator dials 207 of the measuring unit are located at the front end of the scale 302. The scale 302 directly displays the liquid level difference between the two indicator dials 207, which is the thickness of the sludge / oil. Preferably, in this design, the transparent outer cylinder 301 is preferably made of acrylic tubing.

[0034] The assembly of this measuring device is from bottom to top: first, install the sleeve 101, fixing its upper end to the manhole cement cover plate, with the lower part immersed in the sewage tank; then, install the measuring unit, assembling and fixing it to the sleeve 101 via the connecting sleeve 204. The fixed pulley 202 is located above the sewage tank, and the float is inside the tank, located on both sides of the full-hole isolation plate 104; finally, install the display unit, covering the measuring unit with the transparent outer cylinder 301, so that the two indicator dials 207 of the measuring unit are in front of the scale 302, and the bottom of the transparent outer cylinder 301 forms a closed connection with the annular fixing plate 102 at the top of the sleeve 101. Because the continuous oil and sludge thickness measuring device adopts a modular approach, disassembly is very quick.

[0035] This solution customizes floats to suit the densities of different liquid media, using the height difference of the floats to indirectly display the thickness of the upper liquid layer. Combined with its simple structure and ease of manufacture and assembly, it truly achieves real-time, explosion-proof, low-cost, and zero-energy consumption, making it particularly suitable for flammable, explosive, toxic, and hazardous locations without electrical connections. The dual-float structure of this invention represents the simplest form currently available for continuous measurement of oil and sludge thickness in such locations.

[0036] Example 3 Based on the measuring device in Embodiment 1 or 2, this embodiment also proposes a method for continuously measuring the thickness of sludge and oil in a sewage tank, which specifically includes the following steps: Step 1: Fix the hollow sleeve 101 to the cement cover plate of the manhole of the sewage tank (with a hole made on the cover plate) through the annular fixing plate 102 set at its top, and immerse the bottom of the sleeve 101 into the sewage tank. Step 2: The truss 201 of the measuring unit is fixedly connected to the top of the sleeve 101 via the connecting tube 204 and the connecting rod 205. Two fixed pulleys 202 are installed on the truss 201. The water float 208 and oil float 209 are lowered to both sides of the full-hole isolation plate 104 inside the sleeve 101, respectively, to contact the sewage liquid surface and the oily liquid surface. The two floats are respectively connected to a pull rope 203 that passes around the fixed pulley 202. The other end of the two pull ropes 203 is connected to an indicator 207. The height difference between the two indicator 207 can reflect the water and oil level difference. At the same time, the other end of the two pull ropes 203 is also connected to a counterweight 206 for balancing the weight, thereby improving the measurement sensitivity. Step 3: The semi-enclosed transparent outer cylinder 301 of the display unit is inverted and placed on the annular fixing plate 102 at the top of the sleeve 101 to form a closed connection. The liquid level difference between the two indicator dials 207 is read through the scale 302 to obtain the oil thickness.

[0037] In implementing step one, since it is difficult to drill holes in the reinforced concrete structure of the sewage tank, two semi-circular cement manhole covers are fabricated using the location of the manhole cover. A hole is drilled in one of the semi-circular manhole covers to fix the surge protector sleeve 101 of the continuous oil and sludge thickness measuring device; the other semi-circular manhole cover retains its original function. This design has two advantages: first, it does not affect the observation of the sewage tank and the sludge removal through the manhole; second, even if it is necessary to open the manhole cover completely, it is only necessary to disassemble the continuous oil and sludge thickness measuring device and remove the semi-circular cover.

[0038] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A device for continuously measuring the thickness of sludge and oil in a sewage tank, characterized in that, The device includes a sleeve (101), a measuring unit, and a display unit. The sleeve (101) is a hollow cylindrical structure with openings at both the top and bottom. The measuring unit is installed above the central channel of the sleeve (101) and includes a water float (208) and an oil float (209) that enter the sleeve (101) and contact the sewage surface and the oil surface, respectively. The two floats are connected to a pull rope (203) that passes around a fixed pulley (202). The other ends of the two pull ropes (203) are connected to two indicator discs (207) that reflect the water-oil level difference. The display unit is covered outside the measuring unit and includes a transparent outer cylinder (301) and a scale (302) set inside it. The two indicator discs (207) are located at the front end of the scale (302) and the scale (302) directly displays the liquid level difference value of the two indicator discs (207).

2. The continuous oil thickness measurement device in a sewage tank as described in claim 1, characterized in that, The area of ​​the sleeve (101) in contact with the liquid in the sewage tank is provided with a surge protection structure.

3. The continuous oil thickness measurement device in a sewage tank as described in claim 2, characterized in that, The surge protection structure includes a through hole (105) on the outer wall of the sleeve (101) in contact with the liquid in the sewage tank, and a full-hole isolation plate (104) vertically set at the center of the sleeve (101).

4. The continuous oil thickness measurement device in a sewage tank as described in claim 1, characterized in that, The top of the sleeve (101) is provided with a ring-shaped fixing plate (102) around the opening, and the ring-shaped fixing plate (102) is provided with a connecting rod (103) for connecting the measuring unit.

5. A continuous measuring device for the thickness of sludge and oil in a sewage tank as described in claim 1 or 4, characterized in that, The fixed pulley (202) is fixed on the truss (201). The two ends of the truss (201) are connected to the connecting rods (205), and the connecting rods (205) are connected to the connecting tubes (204). The truss (201) is connected and fixed to the connecting rods (103) set at the top of the sleeve (101) through the connecting tubes (204).

6. The continuous oil thickness measurement device in a sewage tank as described in claim 1, characterized in that, The other ends of the two ropes (203) are also connected to counterweights (206) for balancing the weight.

7. The continuous oil thickness measurement device in a sewage tank as described in claim 1, characterized in that, The transparent sleeve (101) is a semi-closed structure with an open bottom and a sealed top. Its bottom is upside down on the annular fixing plate (102) to form a closed connection with it.

8. A continuous measuring device for the thickness of sludge and oil in a sewage tank as described in claim 1 or 7, characterized in that, The transparent outer cylinder (301) is made of acrylic material.

9. A method for continuously measuring the thickness of sludge and oil in a sewage tank, characterized in that, Includes the following steps: Step 1: Fix the hollow sleeve (101) to the opening of the cement cover plate of the manhole of the sewage tank through the annular fixing plate (102) set on its top, and immerse the bottom of the sleeve (101) into the sewage tank. Step 2: The truss (201) of the measuring unit is fixedly connected to the top of the sleeve (101) through the connecting tube (204) and the connecting rod (205). Two fixed pulleys (202) are set on the truss (201). The water float (208) and oil float (209) are lowered to both sides of the full-hole isolation plate (104) inside the sleeve (101) to contact the sewage liquid surface and the oily liquid surface. The two floats are respectively connected to a pull rope (203) that goes around the fixed pulley (202). The other end of the two pull ropes (203) is connected to an indicator (207). The height difference between the two indicator (207) can reflect the water and oil level difference. At the same time, the other end of the two pull ropes (203) is connected to a counterweight (206) for balancing the weight. Step 3: The semi-enclosed transparent outer cylinder (301) of the display unit is inverted and placed on the annular fixing plate (102) at the top of the sleeve (101) to form a closed connection. The liquid level difference between the two indicator dials (207) is read by the scale (302) to obtain the oil thickness.

10. The method for continuous measurement of oily sludge thickness in a sewage tank as described in claim 9, characterized in that, When implementing step one, since it is not easy to make holes in the reinforced concrete structure of the sewage tank, two semi-circular cement manhole covers are made using the location of the manhole cover. A hole is made in one of the semi-circular cement manhole covers to fix the surge protection sleeve (101) of the continuous measurement device for sludge and oil thickness; the other semi-circular manhole cover retains its original function.

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