Automated high head corrosive slurry transfer control system with pipe protection

Abstract

The application discloses an automatic high-drop corrosive slurry conveying control system with pipeline protection devices, which comprises a reslurry tank connected with a first slurry pump, the first slurry pump connected with a second slurry pump, the second slurry pump connected with a third slurry pump, the third slurry pump connected with an uphill slurry conveying pipe, a pipeline protection device one arranged at the highest position of the uphill slurry conveying pipe, the pipeline protection device one connected with a downhill slurry conveying pipe, the downhill slurry conveying pipe connected with an energy dissipation device, the energy dissipation device connected with a slurry buffer tank, the slurry buffer tank connected with a belt filter, the belt filter connected with a backwater pool, the backwater pool connected with a backwater pump, the backwater pump connected with an uphill backwater conveying pipe, the uphill backwater conveying pipe provided with a pipeline protection device two at the highest position, the pipeline protection device two connected with a downhill backwater conveying pipe, and the downhill backwater conveying pipe connected with the reslurry tank. The application guarantees long-term stable operation and safety of production pipeline equipment, and prolongs the service life of the equipment.

Description

Technical Field

[0001] This invention relates to the field of long-distance, high-drop conveying technology for corrosive slurries, and specifically to an automated high-drop corrosive slurry conveying control system with pipeline protection device. Background Technology

[0002] In wet-process phosphoric acid production, the filtration system separates the liquid-phase phosphoric acid from the solid-phase phosphogypsum. Due to the large quantity of phosphogypsum, it cannot be stored on-site. Instead, the phosphogypsum is usually diluted with water to a specific concentration and transported over long distances via multi-stage series pumps. At the phosphogypsum storage area, solid-liquid separation is performed again, with the solid-phase phosphogypsum stored on-site. The filtrate wastewater is returned to the phosphoric acid production plant for reuse. The long-distance transport of slurry and wastewater often involves traversing mountains and valleys, resulting in significant elevation differences. Furthermore, the media are corrosive and abrasive. Considering corrosion resistance and cost, the transport pipelines are generally made of carbon steel lined with PO pipes, connected by segmented flanges.

[0003] Existing problems:

[0004] 1. Due to the large diameter of the conveying pipeline and the poor negative pressure resistance of the steel-lined PO pipe, the conveying pump may suddenly stop due to power outages during production start-up and shutdown, temporary shutdowns, or unforeseen external power outages such as power grid failures or lightning strikes. The slurry in the steel-lined PO pipe will fall from a high point to a low point, and a large negative pressure (vacuum) will be generated inside the pipe due to the siphon effect, causing the steel lining to crack. This will damage the inner lining of the PO pipe. After the inner lining of the steel-lined PO pipe cracks, it is very easy to block the pipeline, and the slurry will also come into direct contact with the outer carbon steel material, which will corrode and perforate, causing slurry leakage and environmental pollution. It is necessary to shut down immediately for replacement, which is time-consuming and labor-intensive and affects the production start-up rate of the phosphoric acid plant.

[0005] 2. When starting up, the pipeline needs to be vented at the highest point to ensure smooth process delivery.

[0006] 3. The large drop and high flow velocity of the pipeline will generate a huge impact energy at the end of the pipeline, which will cause great erosion and wear on the pipeline lining and pose a safety hazard.

[0007] 4. The re-slurry made of phosphogypsum and water has an excessively high concentration, which will lead to high operating load on the delivery pump and short motor life; if the re-slurry concentration is too low, it will waste the system's electrical energy. Summary of the Invention

[0008] The present invention aims to at least solve the technical problems existing in the prior art, and creatively proposes an automated high-drop corrosive slurry conveying control system with pipeline protection device to ensure the safety of equipment and pipelines, as well as the long-term operation of the device.

[0009] To achieve the above objectives, the apparatus of the present invention is as follows:

[0010] An automated high-drop corrosive slurry conveying control system with pipeline protection device includes a reslurry tank connected to the inlet of a primary slurry pump via an underflow pipe. The outlet of the primary slurry pump is connected to the inlet of a secondary slurry pump, and the outlet of the secondary slurry pump is connected to the inlet of a tertiary slurry pump. The outlet of the tertiary slurry pump is connected to an uphill slurry conveying pipe. A pipeline protection device is installed at the highest point of the uphill slurry conveying pipe, and the outlet of the pipeline protection device is connected to the inlet of a downhill slurry conveying pipe. An energy dissipation device is connected to the outlet of the slurry conveying pipe. The energy dissipation device is connected to the slurry buffer tank. The slurry buffer tank is connected to the belt filter. The outlet of the belt filter is connected to a return water tank. The return water tank is connected to the inlet of the return water pump via an underflow pipe. The outlet of the return water pump is connected to the uphill return water conveying pipe. A second pipeline protection device is installed at the highest point of the uphill return water conveying pipe. The outlet of the second pipeline protection device is connected to the downhill return water conveying pipe. The downhill return water conveying pipe is connected to the feed inlet of the re-slurry tank via a return water pipe.

[0011] This device ensures the long-term stable operation of production pipeline equipment, guarantees pipeline operation safety, extends equipment service life, and reduces maintenance workload and spare parts replacement costs.

[0012] The uphill slurry conveying pipe 1 (which is a horizontal pipe at the highest point, with a first vertical opening on the upper side wall of the horizontal pipe where a pressure detection device is installed, and a second vertical opening on the upper side wall of the horizontal pipe where an exhaust and vacuum breaking automatic interlock protection device is installed, the pressure detection device and the exhaust and vacuum breaking automatic interlock protection device constitute the pipeline protection device 1).

[0013] The pressure detection device is equipped with a No. 1 vertical gas phase isolation cylinder, the lower end of which is vertically connected to the No. 1 pipeline via flange one, and the upper end of which is connected to the horn tube via flange two. The horn tube is equipped with a level gauge interface at the top and a pressure gauge interface on the side.

[0014] The automatic interlock protection device for exhaust and vacuum breaking is equipped with a No. 2 vertical gas phase isolation cylinder, the lower end of which is vertically connected to the No. 2 pipeline via flange four, and the upper end of which is connected to the liquid seal isolator via flange five, and is connected to the central pipe inside the liquid seal isolator. The top of the liquid seal isolator is equipped with an isolator liquid level detection interface, the side wall of the liquid seal isolator is equipped with a clean water supply interface connected to a clean water supply pipe, and the side wall of the liquid seal isolator is equipped with an exhaust and vacuum breaking interface connected to an exhaust and vacuum breaking pipe.

[0015] The slurry conveying pipeline has a large drop and high slurry velocity, which generates tremendous impact energy at the pipeline end, causing significant erosion and wear on the pipeline lining and posing a safety hazard. The pipeline protection device includes a pressure detection device. When the pressure detection device detects excessive pipeline pressure, it will control the energy dissipation device to release the pressure, thereby eliminating the safety hazard and ensuring the normal operation and safety of the pipeline.

[0016] The slurry conveying pipeline has a large diameter, and the steel-lined PO pipe has poor resistance to negative pressure. During production start-up and shutdown, temporary shutdowns, unforeseen power outages, and lightning strikes, the slurry pump may suddenly stop. The slurry in the steel-lined PO pipe will then flow from a high point to a low point, creating a significant negative pressure due to siphoning, resulting in a pipeline vacuum. This can cause the steel lining to crack, damaging the inner PO pipe lining. After the lining cracks, it easily clogs the pipeline, allowing the slurry to directly contact the outer carbon steel material, leading to corrosion, perforation, and leakage, causing environmental pollution. Immediate shutdown and replacement are necessary, which is time-consuming, labor-intensive, and impacts the phosphoric acid plant's production rate. In such situations, the aforementioned automatic vacuum breaking interlock protection device, when detecting a vacuum in the pipeline, will control the device to break the vacuum, thereby ensuring pipeline safety.

[0017] The horn tube level gauge interface is equipped with level gauge 2, and the pressure gauge interface is equipped with pressure gauge 2.

[0018] The isolator liquid level detection interface is connected to the liquid level gauge 3, the clean water supply pipe is equipped with a clean water supply valve, and the exhaust and vacuum breaking pipe is equipped with a switching valve group, which consists of vacuum breaking valve 1, vacuum breaking valve 2, and exhaust valve.

[0019] The pressure signal output terminal of the pressure gauge 2 at the top of the slurry pipe is connected to the pressure signal receiving terminal of the processor at the top of the slurry pipe, and the vacuum breaking control signal output terminal of the processor is connected to vacuum breaking valve 1 and vacuum breaking valve 2.

[0020] The exhaust valve is connected to manual operation button three;

[0021] The liquid level signal output terminal of the liquid seal isolator of the liquid level gauge is connected to the liquid seal isolator signal receiving terminal of the processor, and the clean water supply control signal output terminal of the processor is connected to the clean water supply valve.

[0022] Further description: When the pressure gauge 2 detects that the slurry conveying pipeline generates a large negative pressure due to the siphon effect, forming a pipeline vacuum, the processor controls the vacuum breaking valve 1 and vacuum breaking valve 2 to open the valves, introduce air, increase the pressure inside the pipeline, thereby breaking the pipeline vacuum state and ensuring pipeline safety.

[0023] When starting the pump, the manual operation button three controls the opening of the exhaust valve, ensuring smooth process delivery;

[0024] The vacuum breaking valve assembly, being in direct contact with slurry or sewage, will develop scale, leading to incomplete valve closure and leakage. To address this, the level gauge transmits the liquid level information of the liquid seal isolator to the processor. The processor then controls the operation of the clean water supply valve based on the liquid level of the liquid seal isolator, ensuring the vacuum breaking valve assembly is in a clean water isolation state, preventing scale formation, and guaranteeing long-term reliable operation of the vacuum breaking valve assembly.

[0025] The side wall of the liquid seal isolator is connected to a U-shaped tube, which is filled with water seal. The low liquid level end of the U-shaped tube is connected to the liquid seal isolator, and the high liquid level end of the U-shaped tube is connected to a mechanical negative pressure protection tube. The opening end of the mechanical negative pressure protection tube is vertically downward and funnel-shaped. A sealing ball is installed inside the mechanical negative pressure protection tube. The sealing ball is located in the funnel and fits with the arc surface of the inner wall of the funnel to form a one-way air seal.

[0026] The mechanical negative pressure protection pipe is equipped with a limit plate to limit the excessive stroke of the sealing ball.

[0027] The U-shaped tube is located below the clean water supply pipe to facilitate the receipt of clean water and the formation of a water seal. Alternatively, the clean water supply pipe can be installed on the U-shaped tube, and the vacuum valve assembly can be backwashed from the low liquid level end of the U-shaped tube.

[0028] The slurry conveying pipeline generates a significant negative pressure due to siphon action, creating a pipeline vacuum. The sealing ball, due to this negative pressure, moves away from the pipe opening, forming a passage with the outside of the pipe, thereby introducing air, increasing the internal pressure, breaking the vacuum, and ensuring pipeline safety. Furthermore, in the event of a failure of the automatic interlocking protection device for venting and breaking the vacuum, the aforementioned U-shaped tube, mechanical negative pressure protection tube, and sealing ball can replace the automatic interlocking protection device to break the vacuum effect and ensure pipeline safety. The water seal in the U-shaped tube can prevent the leakage of corrosive gases and environmental pollution. Simultaneously, the water seal can buffer the negative pressure impact caused by the siphon action, ensuring pipeline safety.

[0029] The energy dissipation device is a horizontal blind pipe with a first outlet and a second outlet vertically opened on the upper side wall of the horizontal blind pipe.

[0030] The first outlet is connected to the slurry buffer tank via an emergency pressure relief pipe;

[0031] The second outlet is connected to the slurry buffer tank via a pressure regulating pipe;

[0032] A primary nozzle and a secondary nozzle are provided on the horizontal blind pipe between the first outlet and the second outlet.

[0033] The slurry conveying pipeline has a large drop and high slurry velocity, which generates significant impact energy at the pipeline end, causing severe erosion and wear on the pipeline lining and posing a safety hazard. To address this safety hazard, the energy dissipation device works in conjunction with the pipeline protection device to release pipeline pressure, ensuring pipeline safety and normal operation.

[0034] The emergency pressure relief pipe is equipped with an emergency pressure relief valve, and the pressure regulating pipe is equipped with a pressure regulating valve.

[0035] The pressure output signal terminal of the pressure gauge 2 is connected to the pressure signal receiving terminal of the processor, and the emergency pressure relief control signal output terminal of the processor is connected to the emergency pressure relief valve.

[0036] The pressure output signal terminal of the pressure gauge 2 is connected to the pressure input signal terminal of the pressure control PID controller, and the pressure regulation signal output terminal of the pressure control PID controller is connected to the pressure regulating valve.

[0037] To further describe, when a foreign object enters and clogs the nozzle of the energy dissipation device, causing the pressure in the slurry pipeline to rise, the processor will control the emergency pressure relief valve to open and perform emergency pressure relief, so that the pipeline pressure returns to the normal value, thereby ensuring pipeline safety.

[0038] When the slurry pipeline pressure is within the normal range, the pressure control PID regulator automatically adjusts the opening of the pressure regulating valve according to the slurry pipeline pressure to ensure the normal operation of the pipeline.

[0039] The second pipeline safety protection device has the same structure as the first pipeline safety protection device.

[0040] The first pipeline safety protection device is used to protect the safety of the slurry conveying pipeline, and the second pipeline safety protection device is used to protect the safety of the return water conveying pipeline.

[0041] The end of the return water pipeline is provided with a return water auxiliary pipe that connects to the return water regulating port of the reslurry tank, and a water filling control valve is provided on the return water auxiliary pipe;

[0042] A density meter is installed on the resizing tank;

[0043] The reslurry density signal output terminal of the densitometer is connected to the reslurry density signal input terminal of the density control PID controller, and the water addition regulation signal output terminal of the density control PID controller is connected to the water addition regulation valve.

[0044] The re-slurry prepared from phosphogypsum and water has several drawbacks. Excessive concentration in the re-slurry leads to high load on the delivery pump and a short motor lifespan; conversely, insufficient concentration wastes system energy. By controlling the opening of the water supply regulating valve using a density-controlled PID controller, the water supply volume is adjusted to maintain a stable re-slurry concentration at an appropriate level. This effectively saves system energy, ensures stable pump load, and extends the motor's lifespan.

[0045] A level gauge is installed on the reslurry tank;

[0046] The outlet of the three-stage slurry pump is equipped with a flow meter and a pressure gauge.

[0047] The reslurry tank level signal output terminal of the level gauge is connected to the reslurry tank level signal input terminal of the level control PID controller, and the setpoint signal output terminal of the level control PID controller is connected to the setpoint terminal of the flow control PID controller.

[0048] The slurry pump pressure signal output terminal of the flow meter 1 is connected to the slurry pump pressure signal input terminal of the flow control PID regulator 1, the slurry pump frequency conversion regulation signal output terminal of the flow control PID regulator 1 is connected to the slurry pump frequency conversion regulation signal receiving terminal of the automatic frequency converter 1, and the slurry pump frequency conversion regulation execution terminal of the automatic frequency converter 1 is connected to the three-stage slurry pump.

[0049] Secondary slurry pump connected to speed regulator one;

[0050] The first-stage slurry pump is connected to the second speed regulator.

[0051] The above device uses a level-flow cascade regulation system to control the rotation speed of the three-stage slurry pump, thereby changing the outlet flow of the slurry pump and keeping the liquid level in the reslurry tank within the normal range. This maximizes the protection of the slurry pump from cavitation, extends the service life of the equipment, and reduces maintenance workload and spare parts replacement costs.

[0052] The primary and secondary slurry pumps are manually adjustable for starting or daily fine-tuning, and their speed is controlled in coordination with that of the tertiary slurry pump.

[0053] The slurry has a high density and a steep gradient in the pipeline, requiring significant power to ensure long-distance transport. A series of primary, secondary, and tertiary slurry pumps work together to enhance the power for slurry transport and guarantee its long-distance delivery.

[0054] The outlet of the return water pump is equipped with a pressure gauge 3 and a flow meter 2;

[0055] The return water pump flow signal output terminal of the flow meter 2 is connected to the return water pump flow signal input terminal of the flow control PID regulator 2. The return water pump frequency conversion regulation signal output terminal of the flow control PID regulator 2 is connected to the return water pump frequency conversion regulation signal receiving terminal of the automatic frequency converter 2. The execution terminal of the automatic frequency converter 2 is connected to the return water pump.

[0056] The return water pipeline has a steep slope, requiring power support to ensure long-distance transport. The return water pump provides the power for transporting the return water, ensuring its long-distance delivery. The flow control PID controller controls the speed of the return water pump motor, thereby controlling the return water flow rate and keeping the liquid level in the return water tank within the normal range.

[0057] All signals from the device are connected to the DCS control system. A remote I / O cabinet is installed at the top pipeline safety protection point, far away from the centralized production area. All instrument detection signals and control signals enter the remote I / O cabinet, which is connected to the DCS control system cabinet via optical fiber.

[0058] By adopting on-site remote I / O cabinets, the laying length of signal lines at a large number of measurement and control points is reduced, making control and interlocking safer and more reliable.

[0059] The beneficial effects of this invention are: the automatic interlock protection device for exhaust and vacuum breaking detects whether the pipeline is in a vacuum state and interlocks and controls the vacuum breaking valve group to break the vacuum state of the pipeline, avoids high vacuum damage to the PO lining layer of the pipeline, avoids environmental risks, and ensures the long-term stable operation of production pipeline equipment;

[0060] By adopting water isolation measures for the vacuum breaking valve group, the scale formation caused by direct contact between the vacuum breaking valve group and the slurry or sewage is avoided, which could lead to the valve not closing tightly and causing leakage, thus ensuring the long-term reliable operation of the vacuum breaking valve group.

[0061] The pressure is released by the interlocking action of the pressure detection device and the energy dissipation device, ensuring the safe operation of the pipeline;

[0062] The speed of the three-stage slurry pump is controlled by the liquid level-flow cascade regulation system, which stabilizes the liquid level in the reslurry tank, maximizes the protection of the slurry pump from cavitation, extends the service life of the equipment, and reduces maintenance workload and spare parts replacement costs.

[0063] By using a density control PID controller, the opening of the water supply valve is automatically adjusted to keep the concentration of the slurry stable at a suitable level, thereby effectively saving system power energy, ensuring stable load on the delivery pump, and extending the service life of the motor. Attached Figure Description

[0064] Figure 1 A schematic diagram of the slurry conveying process;

[0065] Figure 2This is a schematic diagram of a pipeline safety protection device.

[0066] Figure 3 This is a schematic diagram of a liquid-sealed isolator device;

[0067] Figure 4 This is a schematic diagram of the energy dissipation device and its protection and control system.

[0068] Figure 5 This is a schematic diagram of instrument automation control and interlocking.

[0069] Figure 6 This is a schematic diagram of a U-shaped tube for exhaust and vacuum breaking. Detailed Implementation

[0070] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0071] like Figure 1 As shown, the reslurry tank 1 is connected to the feed end of the primary slurry pump 2 via an underflow pipe. The discharge end of the primary slurry pump 2 is connected to the feed end of the secondary slurry pump 3. The discharge end of the secondary slurry pump 3 is connected to the feed end of the tertiary slurry pump 4. The discharge end of the tertiary slurry pump 4 is connected to the uphill slurry conveying pipe 5. The highest point of the uphill slurry conveying pipe 5 is equipped with a pipeline protection device 6. The outlet of the pipeline protection device 6 is connected to the inlet of the downhill slurry conveying pipe 7. The outlet of the downhill slurry conveying pipe 7 is connected to an energy dissipation device 8. Device 8 is connected to slurry buffer tank 9, which is connected to belt filter 10. The outlet of belt filter 10 is connected to return water tank 11. Return water tank 11 is connected to the inlet of return water pump 12 via underflow pipe. The outlet of return water pump 12 is connected to uphill return water conveying pipe 13. Uphill return water conveying pipe 13 is equipped with pipeline protection device 2 14 at its highest point. The outlet of pipeline protection device 2 14 is connected to downhill return water conveying pipe 15. Downhill return water conveying pipe 15 is connected to the feed inlet of reslurry tank 1 via return water pipe.

[0072] like Figure 2 , Figure 3 , Figure 5 , Figure 6 As shown, the highest point of the uphill slurry conveying pipe 5 is a horizontal pipe. The upper side wall of the horizontal pipe has a first vertical opening and a pressure detection device is installed there. The upper side wall of the horizontal pipe has a second vertical opening and an exhaust and vacuum breaking automatic interlock protection device is installed there. The pressure detection device and the exhaust and vacuum breaking automatic interlock protection device constitute the pipeline protection device 6.

[0073] The pressure detection device is equipped with a vertical gas phase isolation cylinder 6-3, the lower end of which is vertically connected to pipe 6-1 via flange 6-2, and the upper end of which is connected to a horn tube 6-5 via flange 6-4. The horn tube 6-5 is equipped with a level gauge interface at the top and a pressure gauge interface on the side.

[0074] The automatic interlock protection device for exhaust and vacuum breaking is equipped with a 2# vertical gas phase isolation cylinder 6-8, the lower end of which is vertically connected to the 2# pipeline 6-6 via flange four 6-7, and the upper end of which is connected to the liquid seal isolator 6-10 via flange five 6-9, and is connected to the central pipe 6-10-4 inside the liquid seal isolator 6-10. The top of the liquid seal isolator 6-10 is equipped with an isolator liquid level detection interface 6-10-6, the side wall of the liquid seal isolator 6-10 is equipped with a clean water supply interface 6-10-5 connected to a clean water supply pipe, and the side wall of the liquid seal isolator 6-10 is equipped with an exhaust and vacuum breaking interface 6-10-2 connected to an exhaust and vacuum breaking pipe.

[0075] The horn tube 6-5 level gauge interface is equipped with level gauge 2 LT-02, and the pressure gauge interface is equipped with pressure gauge 2 PT-02;

[0076] The isolator liquid level detection interface 6-10-6 is connected to the liquid level gauge LT-03. The clean water supply pipe is equipped with a clean water supply valve XV-01. The exhaust and vacuum breaking pipe is equipped with a switching valve group, which consists of vacuum breaking valve 1XV-02, vacuum breaking valve 2XV-03, and exhaust valve XV-04.

[0077] The pressure gauge PT-02 is used to detect the pressure at the top of the slurry pipe, and it needs to measure both positive and negative pressures, using an absolute pressure transmitter; the level gauge LT-02 is used to detect the liquid level in the gas phase isolation cylinder, using a radar level gauge; the level gauge LT-03 is used to detect the liquid level in the liquid seal isolator, and due to the limited space, it uses a single-rod guided wave radar level gauge; all control valves are pneumatically driven, and the switching valves are metal hard-seal full-bore ball valves. The valve body and internal parts are all made of 316L stainless steel, which has a simple structure, low failure rate, strong corrosion resistance, and long service life.

[0078] The pressure gauge PT-02 transmits the pressure of the slurry pipeline to the processor. When the pressure of the slurry pipeline reaches the lower limit of the vacuum setting, the processor controls the vacuum breaking valve 1XV-02 and vacuum breaking valve 2XV-03 to open the valves and break the vacuum state of the pipeline.

[0079] When starting the pump, manually operate button 3HS-01 to control the exhaust valve XV-04;

[0080] The level gauge LT-03 transmits the liquid level of the liquid seal isolator to the processor. When the liquid level of the liquid seal isolator is lower than the lower limit, the processor controls the clean water supply valve XV-01 to open the valve. After the liquid level reaches the upper limit, the valve is closed.

[0081] like Figure 6As shown, a U-shaped tube 6-10-7 is connected to the side wall of the liquid seal isolator 6-10. The U-shaped tube 6-10-7 is filled with water seal. The low liquid level end of the U-shaped tube 6-10-7 is connected to the liquid seal isolator 6-10. The high liquid level end of the U-shaped tube 6-10-7 is connected to a mechanical negative pressure protection tube 6-10-8. The opening end of the mechanical negative pressure protection tube 6-10-8 is vertically downward and funnel-shaped. A sealing ball 6-10-9 is provided inside the mechanical negative pressure protection tube 6-10-8. The sealing ball 6-10-9 is located in the funnel and fits with the arc surface of the inner wall of the funnel to form a one-way air seal.

[0082] The mechanical negative pressure protection pipe is equipped with a limit plate to limit the excessive stroke of the sealing ball.

[0083] The U-shaped tube is located below the clean water supply pipe to facilitate the receipt of clean water and the formation of a water seal. Alternatively, the clean water supply pipe can be installed on the U-shaped tube, and the vacuum valve assembly can be backwashed from the low liquid level end of the U-shaped tube.

[0084] The slurry conveying pipeline creates a pipeline vacuum. Due to the negative pressure, the sealing ball moves away from the pipe opening, forming a passage with the outside of the pipe, thereby introducing air, increasing the internal pressure of the pipeline, breaking the vacuum state, and ensuring pipeline safety. Furthermore, if the automatic interlocking protection device for venting and breaking the vacuum fails, the aforementioned U-shaped tube, mechanical negative pressure protection tube, and sealing ball can replace the automatic interlocking protection device for venting and breaking the vacuum effect inside the pipe, ensuring pipeline safety. The water seal in the U-shaped tube can prevent the leakage of corrosive gases and environmental pollution. Simultaneously, the water seal can buffer the negative pressure impact caused by the siphon effect in the pipeline, ensuring pipeline safety.

[0085] like Figure 4 , Figure 5 As shown, the energy dissipation device 8 is a horizontal blind pipe, with a first outlet 8-4 and a second outlet 8-5 vertically opened on the upper side wall of the horizontal blind pipe;

[0086] The first outlet 8-4 is connected to the slurry buffer tank 9 via an emergency pressure relief pipe;

[0087] The second outlet 8-5 is connected to the slurry buffer tank 9 via a pressure regulating pipe;

[0088] A primary nozzle 8-1 and a secondary nozzle 8-2 are provided on the horizontal blind pipe between the first outlet 8-4 and the second outlet 8-5.

[0089] The emergency pressure relief pipe is equipped with an emergency pressure relief valve XV-05, and the pressure regulating pipe is equipped with a pressure regulating valve PV-02;

[0090] The above nozzles are made of highly wear-resistant zirconium oxide material; the pressure regulating valve PV-02 is an eccentric rotary valve, and the valve body and internal parts are made of 316L stainless steel. The parts in contact with the medium are treated with wear-resistant and erosion-resistant processes, and the valve action is selected as FO air-closing; the emergency pressure relief valve XV-05 is a metal hard-seal full-bore ball valve, and the valve internal parts are made of 316L + hard alloy.

[0091] The pressure gauge PT-02 transmits the slurry pipeline pressure to the processor. When the slurry pipeline pressure reaches the upper limit set by the pipeline pressure, the processor controls the emergency pressure relief valve XV-05 to open the valve and perform emergency pressure relief, so that the pipeline pressure returns to the normal value.

[0092] The pressure gauge PT-02 transmits the slurry pipeline pressure to the pressure control PID regulator 23. When the slurry pipeline pressure is within the normal range, the pressure control PID regulator 23 automatically controls and adjusts the opening of the pressure regulating valve PV-02 according to the slurry pipeline pressure.

[0093] The pipeline safety protection device 214 has the same structure as the pipeline safety protection device 16; and the equipment and pipeline materials of the pipeline safety protection device are all made of corrosion-resistant 316L stainless steel.

[0094] All instruments and control signals of the pipeline protection device 16, pipeline protection device 214, and energy dissipation device 8 are connected to the remote I / O cabinet 16 installed nearby. The remote I / O cabinet is connected to the main device DCS control system cabinet 17 by optical fiber.

[0095] like Figure 1 , Figure 5 The end of the return water pipeline is provided with a return water auxiliary pipe that connects to the return water regulating port of the reslurry tank 1, and a water filling control valve DV-01 is provided on the return water auxiliary pipe;

[0096] The resizing tank 1 is equipped with a densitometer DT-01;

[0097] The densitometer DT-01 is used to detect the density of the reslurry. The positive and negative pressure diaphragms of the densitometer DT-01 are both installed on the side wall of the reslurry tank 1 and are located below the controlled liquid level.

[0098] The density meter DT-01 transmits the density of the re-slurry to the density control PID controller 20. The density control PID controller 20 controls the opening of the water addition regulating valve DV-01 according to the re-slurry density, thereby controlling the amount of water added and keeping the re-slurry concentration stable.

[0099] like Figure 1 , Figure 5 The reslurry tank 1 is equipped with a level gauge LT-01;

[0100] The outlet of the three-stage slurry pump 4 is equipped with a flow meter FT-01 and a pressure gauge PT-01;

[0101] The LT-01 level gauge is used to detect the level of the re-slurry. To avoid the re-slurry from sticking to the level detection probe and affecting the detection results, the LT-01 level gauge is preferably a non-contact radar level gauge, using a 316L+PTFE process sealed antenna. The FT-01 flow meter is used to detect the outlet flow of the three-stage slurry pump 4, using an electromagnetic flow meter. The PT-01 pressure gauge is used to detect the outlet pressure of the three-stage slurry pump 4, using a diaphragm pressure transmitter with a 316L diaphragm material.

[0102] The level gauge LT-01 transmits the reslurry level to the level control PID controller 21. The level control PID controller 21 obtains a given value based on the reslurry level and transmits the given value to the flow control PID controller 22.

[0103] Meanwhile, the flow meter FT-01 transmits the outlet flow of the three-stage slurry pump 4 to the flow control PID regulator 22. The flow control PID regulator 22 controls the output frequency of the automatic frequency converter SC-01 according to the given value and the outlet flow of the three-stage slurry pump 4, and controls the rotation speed of the three-stage slurry pump 4 through the output frequency.

[0104] Speed ​​controller HC-01 controls the secondary slurry pump 3;

[0105] Speed ​​controller HC-02 controls the first-stage slurry pump 2.

[0106] The primary slurry pump 2, the secondary slurry pump 3, and the tertiary slurry pump 4 are all driven by frequency converters. The primary slurry pump 2 and the secondary slurry pump 3 have manual frequency converter actuators, while the tertiary slurry pump 4 has an automatic frequency converter actuator.

[0107] A level-flow cascade regulation system was adopted to control the three-stage slurry pump. This system automatically adjusts the rotation speed of the three-stage slurry pump 4 by adjusting the reslurry level and the slurry pump outlet flow rate, thereby changing the slurry pump outlet flow rate and keeping the liquid level in the reslurry tank within the process control range.

[0108] The primary and secondary slurry pumps are manually adjustable for starting or daily fine-tuning, and their speed is controlled in coordination with that of the tertiary slurry pump.

[0109] like Figure 1 , Figure 5 The outlet of the return water pump 12 is equipped with a pressure gauge PT-03 and a flow meter FT-02.

[0110] The pressure gauge PT-03 is used to detect the outlet pressure of the return water pump. It is a diaphragm pressure transmitter with a diaphragm material of 316L. The flow meter FT-01 is used to detect the outlet flow of the return water pump. It is an electromagnetic flow meter.

[0111] The flow meter FT-02 transmits the return water pump outlet flow to the flow control PID regulator 24. The flow control PID regulator 24 controls the output frequency of the automatic frequency converter SC-04 according to the return water pump outlet flow, and controls the speed of the return water pump motor through the output frequency, thereby stabilizing the return water flow.

[0112] The return water pump 12 is driven by a frequency converter motor.

[0113] The detection instruments and control signals involved in the reslurry tank 1, the primary slurry pump 2, the secondary slurry pump 3, the tertiary slurry pump 4, etc., are all sent into the DCS control cabinet 17.

[0114] The above-described working process is a conventional adjustment method commonly used by those skilled in the art. The main innovation lies in the product design concept, equipment structure, and configuration relationship of this invention.

[0115] Although embodiments of the present invention have been shown and described, these embodiments are not intended to limit the present invention, and the present invention is not limited to the examples given above. Those skilled in the art will understand that changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and such changes should also fall within the scope of protection of the present invention.

Claims

1. An automated high-drop corrosive slurry conveying control system with pipeline protection device, characterized in that: The re-slurry tank (1) is connected to the feed end of the primary slurry pump (2) via the underflow pipe. The discharge end of the primary slurry pump (2) is connected to the feed end of the secondary slurry pump (3). The discharge end of the secondary slurry pump (3) is connected to the feed end of the tertiary slurry pump (4). The discharge end of the tertiary slurry pump (4) is connected to the uphill slurry conveying pipe (5). The highest point of the uphill slurry conveying pipe (5) is equipped with a pipeline protection device (6). The outlet of the pipeline protection device (6) is connected to the inlet of the downhill slurry conveying pipe (7). The outlet of the downhill slurry conveying pipe (7) is connected to an energy dissipation device (8). The slurry buffer tank (9) is connected to the belt filter (10). The outlet of the belt filter (10) is connected to the return water tank (11). The return water tank (11) is connected to the inlet of the return water pump (12) via the underflow pipe. The outlet of the return water pump (12) is connected to the uphill return water conveying pipe (13). The uphill return water conveying pipe (13) is equipped with a pipeline protection device two (14) at the highest point. The outlet of the pipeline protection device two (14) is connected to the downhill return water conveying pipe (15). The downhill return water conveying pipe (15) is connected to the feed inlet of the reslurry tank (1) via the return water pipe. The highest point of the uphill slurry conveying pipe (5) is a horizontal pipe. The upper side wall of the horizontal pipe has a first vertical opening and a pressure detection device is installed. The upper side wall of the horizontal pipe has a second vertical opening and an automatic interlock protection device for exhaust and vacuum breaking is installed. The pressure detection device and the automatic interlock protection device for exhaust and vacuum breaking constitute the pipeline protection device (6). The pressure detection device is equipped with a 1# vertical gas phase isolation cylinder (6-3), the lower end of which is vertically connected to the 1# pipeline (6-1) via flange one (6-2), and the upper end of which is connected to the horn pipe (6-5) via flange two (6-4). The horn pipe (6-5) is equipped with a level gauge interface at the top and a pressure gauge interface on the side. The automatic interlock protection device for exhaust and vacuum breaking is equipped with a 2# vertical gas phase isolation cylinder (6-8), the lower end of which is vertically connected to the 2# pipeline (6-6) via flange four (6-7), and the upper end of which is connected to the liquid seal isolator (6-10) via flange five (6-9), and is connected to the central pipe (6-10-4) inside the liquid seal isolator (6-10). The top of the liquid seal isolator (6-10) is equipped with an isolator liquid level detection interface (6-10-6), the side wall of the liquid seal isolator (6-10) is equipped with a clean water supply interface (6-10-5) connected to a clean water supply pipe, and the side wall of the liquid seal isolator (6-10) is equipped with an exhaust and vacuum breaking interface (6-10-2) connected to an exhaust and vacuum breaking pipe. The liquid seal isolator (6-10) has a U-shaped tube (6-10-7) connected to its side wall. The U-shaped tube (6-10-7) is filled with water seal. The low liquid level end of the U-shaped tube (6-10-7) is connected to the liquid seal isolator (6-10). The high liquid level end of the U-shaped tube (6-10-7) is connected to a mechanical negative pressure protection tube (6-10-8). The opening end of the mechanical negative pressure protection tube (6-10-8) is vertically downward and funnel-shaped. A sealing ball (6-10-9) is installed inside the mechanical negative pressure protection tube (6-10-8). The sealing ball (6-10-9) is located in the funnel and fits with the arc surface of the inner wall of the funnel to form a one-way air seal. The mechanical negative pressure protection pipe is equipped with a limit plate to restrict the excessive stroke of the sealing ball.

2. The automated high-drop corrosive slurry conveying control system with pipeline protection device according to claim 1, characterized in that: The horn tube (6-5) is equipped with a level gauge 2 (LT-02) at the level gauge interface and a pressure gauge 2 (PT-02) at the pressure gauge interface. The isolator level detection interface (6-10-6) is connected to level gauge three (LT-03), the clean water supply pipe is equipped with a clean water supply valve (XV-01), and the exhaust and vacuum breaking pipe is equipped with a switching valve group, which consists of vacuum breaking valve 1 (XV-02), vacuum breaking valve 2 (XV-03), and exhaust valve (XV-04). The pressure signal output terminal of the pressure gauge 2 (PT-02) is connected to the pressure signal receiving terminal of the slurry pipe top of the processor, and the vacuum breaking control signal output terminal of the processor is connected to the vacuum breaking valve 1 (XV-02) and the vacuum breaking valve 2 (XV-03). The exhaust valve (XV-04) is connected to manual operation button three (HS-01). The liquid level signal output terminal of the liquid seal isolator of the liquid level gauge three (LT-03) is connected to the liquid seal isolator signal receiving terminal of the processor, and the clean water supply control signal output terminal of the processor is connected to the clean water supply valve (XV-01).

3. The automated high-drop corrosive slurry conveying control system with pipeline protection device according to claim 2, characterized in that: The energy dissipation device (8) is a horizontal blind pipe with a first outlet (8-4) and a second outlet (8-5) vertically opened on the upper side wall of the horizontal blind pipe. The first outlet (8-4) is connected to the slurry buffer tank (9) via an emergency pressure relief pipe; The second outlet (8-5) is connected to the slurry buffer tank (9) via a pressure regulating pipe; A primary nozzle (8-1) and a secondary nozzle (8-2) are provided on the horizontal blind pipe between the first outlet (8-4) and the second outlet (8-5).

4. The automated high-drop corrosive slurry conveying control system with pipeline protection device according to claim 3, characterized in that: The emergency pressure relief pipe is equipped with an emergency pressure relief valve (XV-05), and the pressure regulating pipe is equipped with a pressure regulating valve (PV-02). The pressure output signal terminal of the pressure gauge 2 (PT-02) is connected to the pressure signal receiving terminal of the processor at the top of the slurry pipe, and the emergency pressure relief control signal output terminal of the processor is connected to the emergency pressure relief valve (XV-05). The pressure output signal terminal of the pressure gauge 2 (PT-02) is connected to the pressure input signal terminal of the pressure control PID regulator (23), and the pressure regulation signal output terminal of the pressure control PID regulator (23) is connected to the pressure regulating valve (PV-02).

5. The automated high-drop corrosive slurry conveying control system with pipeline protection device according to claim 1, characterized in that: The second pipeline protection device (14) has the same structure as the first pipeline protection device (6).

6. The automated high-drop corrosive slurry conveying control system with pipeline protection device according to claim 1, characterized in that: The end of the return water pipe is provided with a return water auxiliary pipe that connects to the reslurry tank (1) and a return water regulating port is provided on the return water auxiliary pipe. A water addition control valve (DV-01) is provided on the return water auxiliary pipe. The reslurry tank (1) is equipped with a density meter (DT-01). The reslurry density signal output terminal of the density meter (DT-01) is connected to the reslurry density signal input terminal of the density control PID regulator (20), and the water addition regulation signal output terminal of the density control PID regulator (20) is connected to the water addition control valve (DV-01).

7. The automated high-drop corrosive slurry conveying control system with pipeline protection device according to claim 1, characterized in that: The reslurry tank (1) is equipped with a level gauge (LT-01). The outlet of the three-stage slurry pump (4) is equipped with a flow meter (FT-01) and a pressure gauge (PT-01). The reslurry tank level signal output terminal of the level gauge 1 (LT-01) is connected to the reslurry tank level signal input terminal of the level control PID regulator (21), and the setpoint signal output terminal of the level control PID regulator (21) is connected to the setpoint terminal of the flow control PID regulator 1 (22). The slurry pump pressure signal output terminal of the flow meter 1 (FT-01) is connected to the slurry pump pressure signal input terminal of the flow control PID regulator 1 (22), the slurry pump frequency conversion regulation signal output terminal of the flow control PID regulator 1 (22) is connected to the slurry pump frequency conversion regulation signal receiving terminal of the automatic frequency converter 1 (SC-01), and the slurry pump frequency conversion regulation execution terminal of the automatic frequency converter 1 (SC-01) is connected to the three-stage slurry pump (4). The secondary slurry pump (3) is connected to speed regulator 1 (HC-01); The first-stage slurry pump (2) is connected to speed regulator 2 (HC-02).

8. The automated high-drop corrosive slurry conveying control system with pipeline protection device according to claim 1, characterized in that: The outlet of the return water pump (12) is equipped with pressure gauge 3 (PT-03) and flow meter 2 (FT-02); The return water pump flow signal output terminal of the flow meter 2 (FT-02) is connected to the return water pump flow signal input terminal of the flow control PID regulator 2 (24). The return water pump frequency conversion regulation signal output terminal of the flow control PID regulator 2 (24) is connected to the return water pump frequency conversion regulation signal receiving terminal of the automatic frequency converter 2 (SC-04). The execution terminal of the automatic frequency converter 2 (SC-04) is connected to the return water pump (12).

Images