Vacuum conveying pretreatment system and method for sand-water separator in sewage treatment plant

Abstract

The present invention discloses a vacuum conveying pretreatment system and method for a sand-water separator in a sewage treatment plant. The system includes a dehydrating device, a screw conveyor, and a drying device. The dehydrating device is connected to a press at the discharge end of the sand-water separator. The screw conveyor is arranged obliquely between the dehydrating device and the drying device. The drying device is connected to a heat source device, and the sand outlet of the drying device is connected to a vacuum conveying system. The drying device is provided with a micro air cannon device and a rake-tooth oscillator. The drying device uses hot air to dry the dehydrated screening sand. The dried screening sand enters the subsequent vacuum conveying system under the action of the rake-tooth oscillator and the micro air cannon device. During the fully enclosed transportation process of the sand discharged from the sand-water separator, the present invention pre-treats the dehydrated screening sand by dehydration and drying to remove organic matter in the sand, thereby avoiding blockage of the subsequent vacuum conveying pipeline.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and more particularly to a vacuum conveying pretreatment system and method for a sand-water separator in a sewage plant. Background Art

[0002] During the daily operation of sewage treatment plants, a sand-water separator is generally installed in the pretreatment stage to remove various floating and suspended objects in the sewage. If not handled properly, it will cause trouble and impact on the subsequent treatment process.

[0003] The screen sand produced by the sand-water separator is generally transported by a belt conveyor or a screw conveyor to the press and then sent to the trash can after being squeezed. It is then collected by manual transportation and transported for treatment. Since the screen sand has a strong odor and contains oily substances, this method of treatment will have the following shortcomings: (1) The sand outlet of the sand-water separator has a strong odor, especially in underground plants where environmental testing and hydrogen sulfide monitoring are required to be high; (2) Manually pushing the trash can is labor-intensive and has high costs, and requires constant maintenance of the surrounding environment.

[0004] In order to ensure the environment of the screenings sand collection and transportation workshop and solve the time-consuming and labor-intensive problem of manual transportation, the sewage plant pretreatment area was deeply analyzed and studied. Ultimately, the original open-air sewage pretreatment area was transferred to an underground sealed space for treatment. The vacuum adsorption principle was used to transport the screenings sand and other garbage from various locations to the ground layer through a closed pipeline for transportation. The above-ground part can be transformed into a garden-style landscape. Based on this, the transformation of the sewage plant pretreatment ultra-clean space was completed. Since the screenings sand is squeezed and dehydrated by a high-pressure screw dehydrator, although the apparent moisture content is relatively low and the looseness of the sand has reached the physical properties of vacuum transportation, in actual use and operation, due to the oily substances in the sand, the negative pressure characteristics of the vacuum cause the interstitial water in the material to evaporate, and form organic deposits (including oily substances) in the pipe cavity with organic particles. This will cause many problems such as blockage of the vacuum conveying pipeline. Summary of the Invention

[0005] In view of the above-mentioned defects in the prior art, the purpose of the present invention is to provide a vacuum conveying pretreatment system and method for the sand-water separator of a sewage treatment plant. During the fully enclosed transportation process of the sand out of the sand-water separator, the screen sand after squeezing and dehydration is pretreated by dehydration, drying, etc. to remove organic matter in the sand, thereby avoiding subsequent blockage of the vacuum conveying pipeline.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A first aspect of the present invention provides a vacuum conveying pretreatment system for a sand-water separator in a sewage treatment plant, comprising a dehydrating device, a screw conveyor, and a drying device;

[0008] The dehydration device is connected to the press at the discharge end of the sand-water separator, and is used to dehydrate the screen sand after being pressed;

[0009] The screw conveyor is obliquely arranged between the dehydration device and the drying device, and is used to lift the screenings sand dehydrated by the dehydration device into the drying device;

[0010] The drying device is connected to the heat source device, and the sand outlet of the drying device is connected to the vacuum conveying system; the drying device is provided with a micro air cannon device and a rake-tooth oscillator, and the drying device uses hot air to dry the dehydrated screenings sand. The dried screenings sand enters the subsequent vacuum conveying system under the action of the rake-tooth oscillator and the micro air cannon device.

[0011] Preferably, the feed port at the lower end of the screw conveyor is connected to the discharge port of the dehydration device, and the discharge port at the upper end of the screw conveyor is connected to the drying device.

[0012] Preferably, a discharge bin is provided at the lower portion of the drying device, and the sand outlet is provided at the bottom of the discharge bin;

[0013] The plurality of rake teeth on the rake-tooth oscillator are arranged near the discharge bin at the lower part of the drying device, and the rake-tooth oscillator causes the fine sand particles in the screening sand to fall into the discharge bin through oscillation;

[0014] The micro air cannon device is connected to the drying device via an air inlet provided in the discharge bin. The micro air cannon device uses compressed air to bombard the screening sand with high-speed airflow to break up large pieces of screening sand.

[0015] Preferably, the drying device is provided with a level meter and a deodorizing air duct.

[0016] Preferably, the heat source device is connected to a hot air blower, and the heat source device is connected to the hot air outlet on the discharge bin of the drying device through a high-temperature resistant hose;

[0017] The hot air blower blows air into the heat source device for heating, and the heated hot air enters the drying device through a high-temperature resistant hose to participate in the drying process of the screening sand.

[0018] A second aspect of the present invention provides a vacuum conveying pretreatment method for a sand-water separator in a sewage treatment plant, wherein the vacuum conveying pretreatment system for a sand-water separator in a sewage treatment plant as described in the first aspect of the present invention is used to perform the following steps:

[0019] S1, the screenings sand from the sand-water separator is squeezed and transported to the dehydration device for dehydration treatment;

[0020] S2, the dehydrated screenings sand is lifted to the drying device by a screw conveyor for drying. After the organic matter in the screenings sand is removed by hot air, the dried screenings sand enters the subsequent vacuum conveying system under the oscillation of the rake-tooth oscillator and the bombardment of the micro air cannon device.

[0021] Preferably, in step S1, the residence time of the screenings sand in the dehydration device is 15 to 20 seconds.

[0022] Preferably, in step S2, the time for the screenings sand to pass through the screw conveyor is 25 to 35 seconds; and the residence time of the screenings sand in the drying device is 60±5 minutes.

[0023] Preferably, in step S2:

[0024] The temperature of the hot air used in the drying process is 50-60°C;

[0025] The micro air cannon device performs bombardment every 20 to 25 minutes.

[0026] Preferably, in step S2, the screenings sand entering the vacuum conveying system meets the following requirements: moisture content ≤ 30 wt%, particle size < 10 mm.

[0027] The vacuum conveying pretreatment system and method for a sand-water separator in a sewage treatment plant provided by the present invention have the following advantages:

[0028] 1. The present invention mainly targets the screenings sand from the sand-water separator. The screenings sand after squeezing and dehydration is pre-processed by crushing, conveying, drying, etc. On the one hand, hot air is used to dry the screenings sand to reduce its moisture content. On the other hand, organic matter in the screenings sand is removed, thereby facilitating the subsequent vacuum conveying of the screenings sand and avoiding blockage of the vacuum pipeline of the vacuum adsorption system.

[0029] 2. The present invention is suitable for vacuum transportation of sand-water separators, and has positive significance and effects on the automated collection and intensive management of screening sand, as well as the creation of ultra-clean spaces in pre-treatment areas of sewage treatment plants.

[0030] 3. The present invention can realize the closed transportation of sand from the sand-water separator, prevent the overflow of toxic and harmful gases such as hydrogen sulfide, and improve the intrinsic safety of the equipment; reduce the manual pushing of garbage bins and improve the automatic operation capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of the vacuum conveying pretreatment system for the sand-water separator of a sewage plant of the present invention;

[0032] Figure 2 It is a schematic structural diagram of the drying device of the present invention;

[0033] Figure 3 is a side view of the drying device of the present invention;

[0034] Figure 4 This is a layout diagram of the deodorizing air duct and hot air outlet on the drying device of the present invention;

[0035] Among them, 10. Dehydration device; 20. Screw conveyor; 30. Drying device; 31. Discharge bin; 32. Rake-tooth oscillator; 33. Deodorization air duct; 34. Level meter; 35. Hot air outlet; 36. Sand outlet; 37. Micro air cannon device; 40. Heat source device; 41. Hot air blower; 42. High-temperature resistant hose. DETAILED DESCRIPTION

[0036] In order to better understand the above technical solutions of the present invention, the technical solutions of the present invention are further described below with reference to the accompanying drawings and embodiments.

[0037] Urban sewage treatment plants are used in sand-water separator systems. Traditionally, a press or a spiral dewatering machine is used to squeeze and dehydrate the sand from the sand-water separator and then send it to a trash can. The sand is then collected by manual transportation and transported for external treatment. This collection and transportation method has many problems, and there is no similar method to learn from. Therefore, through in-depth analysis and research on the sewage treatment plant pretreatment workshop, the original open-ground sewage pretreatment area was eventually transferred to an underground sealed space for treatment, and the vacuum adsorption principle was used to transport the screen residue and other garbage from various places to the ground layer through a closed pipeline for transportation, while the above-ground part can be transformed into a garden-style landscape, thereby reducing environmental pollution during sewage treatment, effectively improving the plant environment of the sewage treatment plant, and improving the air quality of the plant. On this basis, the transformation of the sewage treatment plant pretreatment ultra-clean space was completed.

[0038] The present invention mainly focuses on the pretreatment and transportation of screen sand in sand-water separators, and is the core technology in the ultra-clean space renovation plan for pretreatment of sand-water separators in sewage treatment plants. During the vacuum adsorption and transportation process, the negative pressure characteristics of the vacuum cause the interstitial water in the screen sand to evaporate. In addition, the screen sand contains grease-like substances, which will cause the screen sand to form organic deposits during vacuum transportation and block the transportation pipeline. Therefore, in the process of transformation, problems are constantly discovered and solved, and the refinement method is improved. Finally, the present invention achieves continuous operation of vacuum transportation of screen sand, realizes fully enclosed transportation of screen sand, avoids blockage of the transportation pipeline, and ensures the overall environment of the sand-water separator pretreatment area.

[0039] Combine Figure 1As shown, the vacuum conveying pretreatment system for the sand-water separator in a sewage treatment plant provided by the present invention is arranged at the rear end of the discharge of the sand-water separator. Since the on-site space of the pretreatment area of ​​the sand-water separator is limited, the vacuum conveying pretreatment system includes a dehydration device 10, a screw conveyor 20 and a drying device 30. By dehydrating, drying and other pretreatments of the sand discharged from the sand-water separator, the screening sand enters the vacuum adsorption system after meeting the conditions, which can realize the vacuum conveying of the sand discharged from the sand-water separator and improve the environment of the pretreatment area of ​​the sand-water separator.

[0040] Combine Figure 1 As shown, the dehydration device 10 is connected to the press at the discharge end of the sand-water separator. The dehydration device 10 is used to dehydrate the screen sand after pressing and dry the sand particles.

[0041] Combine Figure 1 As shown, the screw conveyor 20 is arranged obliquely between the dehydration device 10 and the drying device 30. The screw conveyor 20 is used to lift the screening sand after dehydration by the dehydration device 10 into the drying device 30. The feed port at the lower end of the screw conveyor 20 is connected to the discharge port of the dehydration device 10, and the discharge port at the upper end of the screw conveyor 20 is connected to the drying device 30.

[0042] Combine Figure 1 As shown, the drying device 30 is connected to the heat source device 40, and the sand outlet 36 of the drying device 30 is connected to the vacuum conveying system; the drying device 30 is provided with a micro air cannon device 37 and a rake-tooth oscillator 32. The drying device 30 uses hot air to dry the dehydrated screening sand. The dried screening sand enters the subsequent vacuum conveying system under the action of the rake-tooth oscillator 32 and the micro air cannon device 37. Figure 2 、 Figure 3 As shown, the purpose of the drying device 30 is to melt the organic matter in the screening sand and further remove the moisture in the screening sand. A discharge bin 31 is provided at the bottom of the drying device 30, and a sand outlet 36 is provided at the bottom of the discharge bin 31; a bottom valve is provided at the sand outlet 36 of the drying device 30. A plurality of rake teeth for screening the screening sand are provided at the bottom of a rake-tooth oscillator 32. These rake teeth are arranged near the discharge bin 31 at the bottom of the drying device 30. The vibration generated by the compressed air of the rake-tooth oscillator 32 drives the plurality of rake teeth to vibrate, thereby enabling the sand particles in the screening sand to be heated evenly and quickly dried during the drying process, and the fine sand particles in the screening sand to fall into the discharge bin 31 due to the oscillation action.

[0043] Combine Figure 2As shown, due to the limited on-site space in the pretreatment area of ​​the sand-water separator, the drying device 30 can only be miniaturized and a stirring device cannot be installed. Therefore, a micro air cannon device 37 is added to the drying device 30. The micro air cannon device 37 is connected to the drying device 30 through an air inlet provided in the discharge bin 31. The micro air cannon device 37 uses the kinetic energy of compressed air to bombard the screening sand with high-speed airflow, breaking up large pieces of screening sand, which can not only control the occurrence of the hot melt effect, but also improve the drying efficiency of the screening sand.

[0044] Combine Figure 3 、 Figure 4 As shown, the drying device 30 is equipped with a level meter 34 and a deodorizing air duct 33. The level meter 34 is used to monitor the material level information in the drying device 30 and issue a material signal. The deodorizing air duct 33 is installed at the top of the drying device 30 to guide the deodorizing equipment in the factory to remove odors.

[0045] Combine Figure 2 As shown, the heat source device 40 is connected to the hot air blower 41, and the heat source device 40 is connected to the hot air outlet 35 of the discharge bin 31 of the drying device 30 via a high-temperature resistant hose 42. The hot air blower 41 blows air into the heat source device 40 for heating. The heated hot air enters the drying device 30 through the high-temperature resistant hose 42 to participate in the drying process of the screening sand.

[0046] The present invention also provides a vacuum conveying pretreatment method for a sand-water separator in a sewage treatment plant, which uses the above vacuum conveying pretreatment system for a sand-water separator in a sewage treatment plant to perform the following steps:

[0047] S1, the screenings sand from the sand-water separator is squeezed and transported to the dehydration device 10 for dehydration treatment;

[0048] The screenings sand coming out of the sand-water separator is conveyed by squeezing and then enters the dehydration device 10 , where it is dehydrated. The residence time of the screenings sand in the dehydration device 10 is 15 to 20 seconds.

[0049] S2, the dehydrated screenings sand is lifted by the screw conveyor 20 to the drying device 30 for drying. After the organic matter in the screenings sand is removed by hot air, the dried screenings sand enters the subsequent vacuum conveying system under the oscillation action of the rake-tooth oscillator 32 and the bombardment action of the micro air cannon device 37.

[0050] The time it takes for the screenings sand to pass through the screw conveyor 20 is 25 to 35 seconds; the screenings sand remains in the drying device 30 for 60 ± 5 minutes, with the specific time determined by the amount of sand discharged. The hot air used in the drying process is at a temperature of 50 to 60°C, which is used to dry the screenings sand in the drying device 30 and remove organic matter from the sand, thereby preventing the subsequent vacuum conveying system from sticking. During the drying process, the rake-tooth oscillator 32 uses timed oscillation to achieve regular screening of the screenings sand, thereby reducing manual intervention, preventing the screenings sand from forming a conical accumulation within the sand-water separator drying device, and avoiding uneven heating of the screenings sand during the drying process. Furthermore, during the drying process, the micro-air cannon device 37 bombards the screenings sand every 20 to 25 minutes to break up larger pieces of screenings sand, ensuring uniform material distribution and preventing large pieces of screenings sand from entering the subsequent vacuum conveying system.

[0051] After the above treatment, the screenings sand entering the vacuum conveying system meets the following requirements: moisture content ≤ 30wt%, particle size < 10mm.

[0052] In summary, the vacuum conveying pretreatment system and method for the sand-water separator of the sewage treatment plant of the present invention transports the sand out of the sand-water separator in a closed manner, which can prevent the overflow of toxic and harmful gases such as hydrogen sulfide, improve the intrinsic safety of the equipment, and at the same time reduce the manual pushing of garbage bins, improve the automation operation capability, optimize the environment of the sewage treatment plant, and reduce environmental pollution during the sewage treatment process; in addition, during the closed transportation process, the screen sand is pre-treated by dehydration, drying, etc., to avoid blockage of the vacuum pipeline of the subsequent vacuum conveying system.

[0053] The renovation of the ultra-clean space for pre-treatment of sewage treatment plants is a major engineering project in Shanghai, and is also the first application in the pre-treatment area of ​​a sewage treatment plant. As the core technology in the renovation plan for the ultra-clean space for pre-treatment of sand and water separators in sewage treatment plants, the present invention adopts the vacuum adsorption principle to transport the screen residue and other garbage from various locations to the ground layer through a closed pipeline for transportation. During the fully enclosed transportation process of the sand out of the sand and water separator, the screen residue sand after squeezing and dehydration is pre-treated by dehydration, drying, etc. to remove organic matter in the sand, thereby avoiding subsequent blockage of the vacuum transportation pipeline.

[0054] Those skilled in the art should recognize that the above embodiments are merely intended to illustrate the present invention and are not intended to limit the present invention. As long as they are within the spirit of the present invention, any changes or modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A vacuum conveying pretreatment system for a sand-water separator in a sewage treatment plant, characterized in that: It includes a dehydrating device, a screw conveyor and a drying device; The dehydration device is connected to the press at the discharge end of the sand-water separator, and is used to dehydrate the screen sand after being pressed; The screw conveyor is obliquely arranged between the dehydration device and the drying device, and is used to lift the screenings sand dehydrated by the dehydration device into the drying device; The drying device is connected to the heat source device, and the sand outlet of the drying device is connected to the vacuum conveying system; the drying device is provided with a micro air cannon device and a rake-tooth oscillator, and the drying device uses hot air to dry the dehydrated screening sand. The dried screening sand enters the subsequent vacuum conveying system under the action of the rake-tooth oscillator and the micro air cannon device, and the rake-tooth oscillator causes the fine sand particles in the screening sand to fall into the discharge bin through the oscillation action of the rake-tooth oscillator, and the micro air cannon device uses compressed air to bombard the screening sand with high-speed airflow to crush large pieces of screening sand.

2. The vacuum conveying pretreatment system for the sand-water separator in a sewage plant according to claim 1, characterized in that: The feed port at the lower end of the screw conveyor is connected to the discharge port of the dehydration device, and the discharge port at the upper end of the screw conveyor is connected to the drying device.

3. The vacuum conveying pretreatment system for the sand-water separator in a sewage plant according to claim 1, characterized in that: A discharge bin is provided at the lower part of the drying device, and a sand outlet is provided at the bottom of the discharge bin; The plurality of rake teeth on the rake-tooth oscillator are arranged near the discharge bin at the bottom of the drying device; The micro air cannon device is connected to the drying device via an air inlet arranged in the discharge bin.

4. The vacuum conveying pretreatment system for the sand-water separator in a sewage plant according to claim 1, characterized in that: The drying device is provided with a level meter and a deodorizing air duct.

5. The vacuum conveying pretreatment system for the sand-water separator in a sewage plant according to claim 1, characterized in that: The heat source device is connected to the hot air blower, and the heat source device is connected to the hot air outlet on the discharge bin of the drying device through a high-temperature resistant hose; The hot air blower blows air into the heat source device for heating, and the heated hot air enters the drying device through a high-temperature resistant hose to participate in the drying process of the screening sand.

6. A vacuum conveying pretreatment method for a sand-water separator in a sewage treatment plant, characterized in that: The following steps are performed using the vacuum conveying pretreatment system for the sand-water separator in a sewage plant as described in any one of claims 1 to 5: S1, the screenings sand from the sand-water separator is squeezed and transported to the dehydration device for dehydration treatment; S2, the dehydrated screenings sand is lifted to the drying device by a screw conveyor for drying. After the organic matter in the screenings sand is removed by hot air, the dried screenings sand enters the subsequent vacuum conveying system under the oscillation of the rake-tooth oscillator and the bombardment of the micro air cannon device.

7. The vacuum conveying pretreatment method for a sand-water separator in a sewage plant according to claim 6, characterized in that: In step S1, the screens sand stays in the dehydration device for 15 to 20 seconds.

8. The vacuum conveying pretreatment method for a sand-water separator in a sewage plant according to claim 6, characterized in that: In step S2, the time for the screenings sand to pass through the screw conveyor is 25 to 35 seconds; the time for the screenings sand to stay in the drying device is 60±5 minutes.

9. The vacuum conveying pretreatment method for a sand-water separator in a sewage treatment plant according to claim 6, characterized in that: In the step S2: The temperature of the hot air used in the drying process is 50-60°C; The micro air cannon device performs bombardment every 20 to 25 minutes.

10. The vacuum conveying pretreatment method for a sand-water separator in a sewage treatment plant according to claim 6, characterized in that: In step S2, the screenings sand entering the vacuum conveying system meets the following requirements: moisture content ≤ 30 wt %, particle size < 10 mm.

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