Chemical injection control system for MTO device

Abstract

The utility model discloses a chemical injection control system for an MTO (Methanol To Olefins) device, which comprises a medicament tank, and a feeding pipe orifice of the medicament tank is communicated with a feeding pipeline with an agent unloading pump; a plurality of groups of liquid conveying pipelines are connected to a discharging pipe of the medicament tank; each liquid conveying assembly comprises a liquid conveying pipeline and a liquid conveying unit, the liquid conveying pipeline in each liquid conveying assembly corresponds to the multiple liquid conveying units, each liquid conveying unit comprises a liquid injection pipeline connected between the corresponding liquid conveying pipeline and the corresponding discharging pipe in parallel, and each liquid injection pipeline is provided with a filter, a calibration column, an injection agent pump and a check valve; a safety valve is arranged at the tail end of the liquid injection pipeline. The system has the beneficial effects that the medicament tank injects the cost yellow inhibitor into different liquids through multiple groups of liquid conveying pipelines, the inhibitor is conveyed in one liquid conveying pipeline through multiple groups of liquid conveying units, the conveying effect is better, and the system has higher adaptability due to the multi-pipeline design, so that different production requirements are met.

Description

Technical Field

[0001] This utility model relates to the field of chemical injection control, specifically to a chemical injection control system for MTO devices. Background Technology

[0002] Methanol-to-olefins (MTO) plants are technologies that use natural gas or coal as feedstock, first converting it into syngas, then using the syngas to produce methanol, and finally converting the methanol into low-carbon olefins such as ethylene and propylene under the action of a catalyst. These olefin products have been widely used in the production of chemical products such as polyolefins. MTO technology provides an innovative process route for producing chemical products from unconventional petroleum resources. In the olefin recovery system of the MTO process, alkaline washing is often used to remove acidic gases such as H2S and CO2 from the product gas. However, in a strongly alkaline environment, oxygen-containing compounds such as aldehydes and ketones in the product gas undergo aldol condensation reactions to generate polymers; unsaturated olefins are prone to free radical polymerization reactions, producing organic sulfides and polysulfides. These polymers condense in the alkaline solution, forming a yellow aqueous alkaline emulsion, commonly known as "butter." When heated or oxidized, butter transforms into polymers, leading to scaling. This scaling, in turn, clogs the distributors and packing voids in the alkali scrubbing tower, causing increased tower pressure differential, increased alkali consumption, and increased waste alkali discharge. It can even reduce the absorption efficiency of the alkali scrubbing tower, affecting the stable operation of the unit and the load on downstream waste alkali treatment units. To reduce butter formation, industry typically optimizes process conditions and adds butter inhibitors to decrease its amount.

[0003] However, traditional butter inhibitors, when injected, are often delivered through a single pipeline structure. This traditional system lacks precise control over the butter, which can easily lead to backflow and inaccurate injection volume, affecting catalytic performance and product quality. Furthermore, if the delivery pipeline is damaged, it is difficult to ensure the continuous online operation of the inhibitor, and it is also difficult to achieve optimal economic benefits and stability.

[0004] Therefore, providing a chemical injection control system for MTO devices is a problem worthy of research. Summary of the Invention

[0005] In order to overcome the shortcomings of the existing technology, the purpose of this utility model is to achieve precise control of butter inhibitors, which not only ensures good performance, but also meets the stability requirements of the equipment, promotes clean production and reduces production costs.

[0006] The purpose of this utility model is achieved as follows:

[0007] This utility model provides a chemical injection control system for an MTO device, including a reagent tank, wherein the inlet of the reagent tank is connected to a feed pipe equipped with a discharge pump.

[0008] The medicine tank's discharge pipe is connected to multiple sets of infusion pipes; the infusion assembly includes infusion pipes and infusion units, with each infusion pipe in the infusion assembly corresponding to multiple sets of infusion units. The infusion unit includes an injection pipe connected in parallel between the infusion pipe and the discharge pipe. The injection pipe is equipped with a filter, a calibration column, an injection pump, and a check valve. The end of the injection pipe is equipped with a safety valve that communicates with the medicine tank.

[0009] As a preferred embodiment, the number of infusion components is no less than three sets.

[0010] As a preferred embodiment, the top of the medicine tank is connected to a safety valve, and the bottom of the medicine tank is connected to a drain valve.

[0011] As a preferred embodiment, a buffer is connected to the end of the infusion tubing.

[0012] As a preferred embodiment, the injection pipe is provided with a valve at the end near the discharge pipe.

[0013] As a preferred embodiment, a level gauge is provided between the discharge pipe and the medicine tank.

[0014] As a preferred embodiment, the filter, the calibration column, the injection pump, the check valve, and the safety valve are arranged in sequence, wherein the filter is located near the discharge pipe.

[0015] As a preferred embodiment, the level gauge, the injection pump, the calibration column, the valve, the safety valve, the tank top safety valve, and the unloading pump are all electrically controlled devices and are also electrically connected to the control device.

[0016] As a preferred embodiment, the control device is connected to cloud data via a wireless communication module.

[0017] Positive and beneficial effects:

[0018] The drug tank injects cost yellow inhibitors into different liquids through multiple sets of infusion pipelines, and delivers the inhibitors through multiple sets of infusion units in one infusion pipeline, resulting in better delivery effect. It can achieve non-stop operation of the inhibitor by using different infusion units.

[0019] In the infusion unit, impurities can be filtered out through a filter, and the injection volume can be precisely controlled by a calibration column and an injection pump. A check valve is used to prevent backflow of the cost yellow inhibitor, ensuring a stable delivery process.

[0020] The multi-pipeline design gives the system strong adaptability, allowing it to be flexibly adjusted according to needs and adapt to different production requirements. This system also significantly improves the efficiency and accuracy of drug delivery, and enhances the safety, reliability and stability of the equipment, ensuring efficient and safe completion of tasks during long-term operation. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structural process of this utility model.

[0022] The diagram shows: 1. Medicine tank; 2. Level gauge; 3. Injection pump; 4. Calibration column; 5. Valve; 6. Check valve; 7. Safety valve; 8. Buffer; 9. Control equipment; 10. Safety valve on top of tank; 11. Unloading pump; 12. Filter; 13. Drain valve. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] See Figure 1 As shown, the present invention provides a chemical injection control system for an MTO device, including a reagent tank 1. The inlet of the reagent tank 1 is connected to a feed pipe with a discharge pump 11. The end of the feed pipe away from the reagent tank 1 is a flexible tube structure. The feed pipe can extend into the butter inhibitor. The discharge pump 11 is used to assist in transporting the butter inhibitor into the reagent tank 1 for storage.

[0025] The discharge pipe of the medicine tank 1 is connected to multiple sets of infusion pipes, which can inject butter inhibitors into different pipes respectively.

[0026] In the specific structure of the infusion pipeline, the infusion assembly includes an infusion pipeline and an infusion unit. Each infusion assembly has an infusion pipeline corresponding to multiple infusion units. The infusion unit includes an injection pipeline connected in parallel between the infusion pipeline and the outlet pipe. The injection pipeline is equipped with a filter 12, a calibration column 4, an injection pump 3, and a check valve 6. During the delivery of the butter inhibitor, the filter 12 can filter impurities delivered to the injection pipeline. Preferably, the filter 12 is a Y-type filter. The end of the injection pipeline is equipped with a safety valve 7 connected to the medicine tank 1. The safety valve 7 can reduce the pressure of the butter inhibitor during the delivery process and prevent the injection pipeline from overloaded or over-pressurized.

[0027] Furthermore, a pressure tank is connected to the top of the reagent tank 1. The pressure tank can reduce the partial pressure of light hydrocarbons by injecting inert gas into the reagent tank 1, thus isolating it from air and meeting safe storage requirements. This avoids air pollution caused by direct venting. A steam purging port is provided on the top of the reagent tank 1.

[0028] In a preferred embodiment, the number of infusion components is no less than three sets. The three sets of infusion components inject butter inhibitors into the strong alkali, medium alkali, and weak alkali processes, respectively. To achieve precise control of small flow rates, the diaphragm of the infusion pump 3 is made of metal, depending on the characteristics of the medium. The accuracy of the infusion pump 3 is required to be higher than ±0.5% within the flow range of 10% to 100%. A pressure gauge is installed on the infusion pump 3 to monitor diaphragm rupture. A check valve 6 is installed at the inlet or outlet of the infusion pump 3 to effectively prevent liquid backflow, protect the infusion pump 3 from damage, and ensure that the outlet pressure and flow rate of the infusion pump 3 remain stable without deviation, thereby ensuring accurate delivery of the drug and avoiding performance degradation due to backflow or pressure fluctuations, thus improving overall operating efficiency. Furthermore, the flow rate can be adjusted manually or electrically, and must have a scale indication. A calibration column 4 is installed at the inlet of the infusion pump 3 for convenient dosage calibration.

[0029] In a preferred embodiment, since there are multiple sets of injection pipes connected in parallel between the infusion pipe and the discharge pipe, one set of injection pipes can be set as a standby state while the others are in use. When there are two sets of injection pipes, one is in standby and the other is in use. When there are three sets of injection pipes, one is in standby and the other is in use. The two injection pipes in use can be delivered by injection pumps 3 with different flow rates to achieve more precise delivery of the butter inhibitor. Furthermore, since each set has a standby injection pipe, continuous use of the device can be guaranteed.

[0030] Furthermore, the filter 12, calibration column 4, injection pump 3, check valve 6, and safety valve 7 are sequentially arranged. The filter 12 is located near the discharge pipe, and the check valve 6 prevents backflow of the injection pump outlet. This arrangement ensures that when the butter inhibitor flows through the injection pipeline, the filter 12 filters the liquid entering the pipeline, and the calibration column 4 accurately measures and calibrates the liquid in the injection pipeline. This ensures that parameters such as flow rate and pressure during the injection process meet preset standards, contributing to the accuracy and controllability of the liquid injection system. The injection pump 3 delivers the butter inhibitor... The oil inhibitor is precisely injected into the pipeline. The injection pump 3 is a high-precision pump that ensures that the liquid is delivered to the designated location at the set flow rate. The injection pump 3 works in conjunction with components such as the calibration column 4 and the check valve 6 to maintain the stability of the injection process. The check valve 6 is located at the outlet of the injection pump 3 and can prevent the oil inhibitor from flowing back into the injection pump 3 or the pipeline. The safety valve 7 can release excessive pressure in the injection pipeline to prevent equipment damage due to excessive pressure. When the system pressure exceeds the safety value, it will automatically open to release excess liquid or gas and protect the entire system from unexpected failures.

[0031] The top of the medicine tank 1 is connected to a safety valve 10, and the bottom of the medicine tank 1 is connected to a drain valve 13. The safety valve 10 is a micro-opening pipeline safety valve with front and rear hand valves and a secondary valve. The drain valve 13 at the bottom is connected to the drain pipe at the bottom of the medicine tank 1, and the end of the infusion pipe is connected to a buffer 8. The buffer 8 can assist the pulsed flow output by the injection pump 3 to play a wave clipping and smoothing role.

[0032] A pressure gauge is installed on buffer 8, which primarily functions as a physical filter. A better filtering effect is achieved when the buffer tank capacity of buffer 8 is more than 10 times larger than the metering pump capacity. A nitrogen inlet, outlet, and a gas pressure gauge are installed on the top of the buffer tank. The liquid material inlet is installed on the side of the buffer tank, at approximately 60%–70% of its height, and the outlet is installed at the bottom of buffer 8. Fluid materials flow into buffer 8 from the top and out from the bottom. The pressure gauge on the top of the buffer tank is used to monitor the nitrogen pressure inside. When the nitrogen pressure is insufficient, nitrogen is replenished using a purging tool.

[0033] A valve 5 is provided at the end of the injection pipe near the discharge pipe, and the opening and closing of the injection pipe can be controlled by the valve 5.

[0034] A level gauge 2 is installed between the discharge pipe and the reagent tank 1. The level gauge 2 is a glass plate level gauge with a millimeter scale. The level gauge mounting flange is equipped with an isolation valve, and a drain valve is installed at the bottom. It is directly connected to the inlet pipeline of the discharge pipe. This setting can prevent the leakage of the medium when emptying.

[0035] Level gauge 2, injection pump 3, calibration column 4, valve 5, safety valve 7, tank top safety valve 10, and unloading pump 11 are all electrical control devices, and are also electrically connected to control device 9. Control device 9 is located in an explosion-proof enclosure with explosion-proof function. The surface of the enclosure is equipped with operation buttons and indicator lights for controlling the electrical control devices, and can independently complete local operation functions.

[0036] The working status and fault status of the electrical control equipment can be sent to the DCS control equipment. The operation of the corresponding electrical control equipment can be controlled by operating buttons, such as the liquid level stop and pump stop function of injection pump 3, thereby controlling the start and stop operation of the metering pump.

[0037] Preferably, the control device 9 is connected to the cloud via a wireless communication module. The data information of the control device 9 can be sent to the cloud for recording through the communication module. The terminal device can then remotely control the main control operation of the system by downloading the data, thereby greatly improving the flexibility and convenience of the chemical injection control system.

[0038] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A chemical injection control system for an MTO (Mechanical Toll Collection) device, comprising a reagent tank (1), characterized in that: The feed pipe with a discharge pump (11) is connected to the feed inlet of the medicine tank (1); The medicine tank (1) has multiple sets of infusion pipes connected to its discharge pipe; The infusion assembly includes an infusion pipeline and an infusion unit. Each infusion pipeline in the infusion assembly corresponds to multiple infusion units. The infusion unit includes an injection pipeline connected in parallel between the infusion pipeline and the discharge pipeline. The injection pipeline is equipped with a filter (12), a calibration column (4), an injection pump (3), and a check valve (6). The end of the injection pipeline is equipped with a safety valve (7) that is connected to the medicine tank (1).

2. The chemical injection control system for an MTO unit according to claim 1, characterized in that: The number of infusion assemblies shall not be less than three sets.

3. A chemical injection control system for an MTO unit according to claim 1, characterized in that: The top of the medicine tank (1) is connected to a safety valve (10), and the bottom of the medicine tank (1) is connected to a drain valve (13).

4. A chemical injection control system for an MTO unit according to claim 3, characterized in that: The infusion tubing is connected to a buffer (8) at the end.

5. A chemical injection control system for an MTO unit according to claim 4, characterized in that: A valve (5) is provided at the end of the injection pipe near the discharge pipe.

6. A chemical injection control system for an MTO unit according to claim 5, characterized in that: A level gauge (2) is provided between the discharge pipe and the medicine tank (1).

7. A chemical injection control system for an MTO unit according to claim 1, characterized in that: The filter (12), the calibration column (4), the injection pump (3), the check valve (6), and the safety valve (7) are arranged in sequence, wherein the filter (12) is close to the discharge pipe.

8. A chemical injection control system for an MTO unit according to claim 6, characterized in that: The level gauge (2), the injection pump (3), the calibration column (4), the valve (5), the safety valve (7), the tank top safety valve (10), and the unloading pump (11) are all electrically controlled devices and are also electrically connected to the control device (9).

9. A chemical injection control system for an MTO unit according to claim 8, characterized in that: The control device (9) is connected to cloud data via a wireless communication module.

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