Boiling bed hot low oil filtering system

Abstract

The utility model relates to the technical field of separation equipment, especially to boiling bed device filter equipment, concretely to a boiling bed hot low oil separation filter system, including with the hot low pressure separator oil discharge port intercommunication's hot low oil separation filter, still including the oil discharge storage tank, the feed inlet of oil discharge storage tank is communicated with the oil discharge port of hot low oil separation filter through the oil discharge pipeline, the discharge port of oil discharge storage tank is communicated with heavy oil pipeline through the oil transfer pipeline, the utility model discloses between hot low oil separation filter and heavy oil pipeline increases the oil discharge storage tank, and the oil discharge storage tank is used as the container of buffering and subsiding, and after the subsidence of hot low oil separation, the catalyst content in the oil product that is transported to heavy oil pipeline subsequently has reduced greatly, and the erosion and abrasion of catalyst particles to heavy oil pipeline are relieved.

Description

Technical Field

[0001] This utility model relates to the field of separation equipment technology, and in particular to fluidized bed filtration equipment, specifically to a fluidized bed hot low-temperature oil separation filtration system. Background Technology

[0002] In the hydrocracking process of heavy oil and residual oil, fluidized bed (or expanded bed) reactors are widely used because they can handle low-quality feedstocks with high metal content and high carbon residue. Under specific operating conditions, feedstock oil, hydrogen, and finely powdered catalyst form a gas-liquid-solid three-phase fluidized bed state for hydrogenation and cracking reactions. The liquid effluent after the reaction undergoes gas-liquid separation in a thermal separator (thermal high-pressure separator, thermal low-pressure separator), and the resulting liquid phase is called thermal low-pressure oil.

[0003] Due to the vigorous movement of the catalyst and the wear of some catalysts during the reaction, the hot low-temperature oil flowing out of the reactor carries fine catalyst particles. If these catalyst particles are not effectively removed, they will enter the downstream fractionation system and heat exchange equipment with the hot low-temperature oil, causing scaling, blockage, and wear in the equipment pipelines, ultimately affecting the quality of downstream products. Therefore, a hot low-temperature oil filter is usually installed before the hot low-temperature oil enters the downstream process to intercept and remove these solid catalyst particles, ensuring the stable operation of subsequent processes.

[0004] In existing technology, when the pressure drop of the hot low-separation oil filter reaches the set upper limit during process system operation, it indicates that a large amount of catalyst has adhered to its internal filter element, reducing its filtration capacity and requiring cleaning. Specifically, the following operations are performed:

[0005] 1. Isolation and pressure relief: Isolate the hot low-pressure oil filter from the process system and release the high-pressure oil and gas inside it.

[0006] 2. Oil phase discharge: The hot low-separation oil accumulated in the hot low-separation oil filter cylinder is discharged. This part of the hot low-separation oil contains a high concentration of intercepted catalyst particles.

[0007] 3. Purging and cleaning: Purge residual oil with nitrogen, then open the cover of the hot low-temperature oil separator for mechanical cleaning or replace the filter element.

[0008] Currently, the common practice in the industry is to directly discharge the catalyst-containing hot low-separation oil discharged from the hot low-separation oil filter in step 2 into the plant's heavy oil sludge pipeline. This discharge method causes serious damage to the heavy oil sludge pipeline:

[0009] Due to the hard and wear-resistant physical properties of the catalyst, the highly abrasive catalyst solid particles continuously scour and cut the inner wall of the heavy oil-contaminated pipeline in the high-speed flowing oil phase.

[0010] Heavy oil sludge pipelines, as public utility pipelines, are used to collect heavy oil sludge from various parts of the system. Designed as a public utility network, they were initially intended to transport liquid oil sludge and did not consider the long-term abrasion caused by catalyst solid particles. The continuous discharge of catalyst-containing hot low-grade oil leads to erosion and wear in the heavy oil sludge pipelines, especially at elbows, tees, valves, and pump inlets—areas where flow velocity and direction change. This not only shortens the service life of the heavy oil sludge pipelines and increases maintenance and replacement costs, but also poses a significant risk of oil leakage due to pipeline thinning and perforation, potentially causing safety and environmental accidents; it can even affect the oil discharge of other units in the system, disrupting the normal operation of the entire process system. Utility Model Content

[0011] To address the technical problem of erosion and wear caused by catalyst-containing hot low-separation oil discharge to heavy oil pipelines, as mentioned in the background art, this utility model provides a fluidized bed hot low-separation oil filtration system.

[0012] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0013] A fluidized bed hot low-pressure oil separation filtration system includes a hot low-pressure oil separation filter connected to the oil outlet of a hot low-pressure separator, and an oil discharge storage tank.

[0014] The inlet of the oil storage tank is connected to the outlet of the hot low-temperature oil filter via an oil discharge pipeline.

[0015] The discharge port of the oil storage tank is connected to the heavy waste oil pipeline via an oil pipeline.

[0016] Furthermore, the oil discharge tank is equipped with a level gauge.

[0017] Furthermore, nitrogen pressure control is installed at the top of the oil discharge tank.

[0018] Furthermore, an oil discharge pump is installed on the oil pipeline.

[0019] Furthermore, a pressure detection device is installed on the outlet pipeline of the oil pump.

[0020] Furthermore, the oil pipeline is also equipped with a filter assembly for intercepting catalyst particles, and the filter assembly is located between the oil discharge tank and the oil discharge pump.

[0021] Furthermore, the filter assembly is a sintered metal filter or a basket filter.

[0022] Furthermore, it also includes direct-flow pipelines;

[0023] The straight discharge pipeline and the oil discharge pipeline are arranged in parallel;

[0024] One end of the direct discharge pipeline is connected to the oil outlet of the hot low-temperature oil filter, and the other end is connected to the heavy sludge oil pipeline.

[0025] Furthermore, a control valve is installed on the direct discharge pipeline.

[0026] In summary, this utility model has the following beneficial technical effects:

[0027] This invention adds an oil drain tank between the hot low-separation oil filter and the heavy oil pipeline. The oil drain tank serves as a buffer and settling container, temporarily storing the hot low-separation oil containing catalyst discharged from the hot low-separation oil filter. The flow rate of the hot low-separation oil is significantly reduced in the tank, providing sufficient settling and separation time for solid catalyst particles. After settling, most of the solid particles are separated at the bottom of the tank, and the catalyst content in the oil subsequently transported to the heavy oil pipeline is greatly reduced. This alleviates the severe erosion and wear of the heavy oil pipeline (especially elbows, tees, etc.) caused by high-hardness catalyst particles, greatly extends the service life of the heavy oil pipeline, and eliminates the risk of oil leakage caused by wear and perforation of the heavy oil pipeline. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of this utility model;

[0029] Explanation of reference numerals in the attached diagram: 1. Fluidized bed reactor; 2. Thermal separator; 21. High-pressure thermal separator; 22. Low-pressure thermal separator; 3. Low-pressure thermal oil filter; 3A - Commonly used low-pressure thermal oil filter; 3B - Backup low-pressure thermal oil filter; 4. Fractionation system; 5. Oil discharge storage tank. Detailed Implementation

[0030] The technical solution of this utility model will be further explained and described below with reference to the accompanying drawings and embodiments, but this utility model is not limited to the embodiments described below.

[0031] Reference Figure 1 The process system, as shown in the figure, includes a fluidized bed reactor 1, a thermal separator 2, a hot low-oil filter 3, and a fractionation system 4 connected in sequence.

[0032] The thermal separator 2 includes a high-pressure thermal separator 21 and a low-pressure thermal separator 22 connected in series, with a flow regulating valve group between the high-pressure thermal separator 21 and the low-pressure thermal separator 22; the feed inlet of the high-pressure thermal separator 21 is connected to the fluidized bed reactor 1, the feed inlet of the low-pressure thermal separator 22 is connected to the liquid phase outlet of the high-pressure thermal separator 21, and the discharge outlet of the low-pressure thermal separator 22 is connected to the low-pressure thermal oil filter 3.

[0033] The hot low-pressure oil separator 3 includes a primary hot low-pressure oil separator 3A and a backup hot low-pressure oil separator 3B connected in parallel. The inlet of the primary hot low-pressure oil separator 3A and the inlet of the backup hot low-pressure oil separator 3B are connected to the outlet of the hot low-pressure separator 22 through a three-way pipe. The outlet of the primary hot low-pressure oil separator 3A and the outlet of the backup hot low-pressure oil separator 3B are connected to the downstream fractionation system 4 through a three-way pipe. A flow regulating valve group is installed between the three-way pipe and the fractionation system 4. The primary hot low-pressure oil separator 3A and the backup hot low-pressure oil separator 3B are used in a standby configuration.

[0034] Under normal operating conditions, feedstock oil, hydrogen, and finely powdered catalyst undergo hydrogenation and cracking reactions in fluidized bed reactor 1. The reaction products pass through hot high-pressure separator 21, where gas-liquid separation is performed. The separated liquid phase then enters hot low-pressure separator 22 for further depressurization after passing through a flow regulating valve group. Hot low-pressure separator 22 discharges hot low-pressure oil containing catalyst solid particles. The hot low-pressure oil containing catalyst solid particles then enters hot low-pressure oil filter 3. Most of the catalyst solid particles are trapped inside the hot low-pressure oil filter 3, while a small amount of catalyst enters the downstream fractionation system 4 with the hot low-pressure oil.

[0035] This utility model provides a fluidized bed hot low-separation oil filtration system, including the aforementioned hot low-separation oil filter 3 and an oil discharge storage tank 5. The oil discharge storage tank 5 is provided with an inlet, an outlet, and a slag discharge outlet. The inlet of the oil discharge storage tank 5 is connected to the hot low-separation oil filter 3 via an oil discharge pipeline. Specifically, the inlet of the oil discharge storage tank 5 is connected to one end of the oil discharge pipeline, and the other end of the oil discharge pipeline is connected via a T-junction to the oil discharge outlet of the commonly used hot low-separation oil filter 3A and the oil discharge outlet of the standby hot low-separation oil filter 3B, respectively. The outlet of the oil discharge storage tank 5 is connected to a heavy waste oil pipeline via an oil delivery pipeline. The slag discharge outlet is located at the bottom of the oil discharge storage tank 5 for periodic sludge removal.

[0036] The core improvement of this invention lies in the addition of an oil drain tank 5 between the hot low-separation oil filter and the heavy sludge pipeline. The oil drain tank 5 is used to receive, temporarily store, and settle the hot low-separation oil containing catalyst solid particles.

[0037] When the pressure differential of the online hot low-pressure oil filter is too large and cleaning is required, first isolate the online hot low-pressure oil filter from the process system, switch the process system to the standby hot low-pressure oil filter, and then drain and clean the hot low-pressure oil filter to be cleaned without affecting the normal operation of the process system.

[0038] The hot low-temperature oil containing solid catalyst particles discharged from the hot low-temperature oil to be cleaned enters the oil discharge storage tank 5 through the oil discharge pipeline. The flow rate of the hot low-temperature oil in the oil discharge storage tank 5 is significantly reduced, providing sufficient time for the solid catalyst particles to settle and separate. After settling, most of the solid catalyst particles are separated at the bottom of the storage tank. Subsequently, the oil sludge (supernatant) in the oil discharge storage tank 5 is transported to the heavy oil pipeline.

[0039] Based on the above implementation methods, the erosion and wear of heavy oil pipelines (especially elbows, tees, etc.) caused by catalyst-containing hot low-separation oil are greatly reduced, the service life of public heavy oil pipelines is greatly extended, and the risk of oil leakage caused by wear and perforation of heavy oil pipelines is eliminated.

[0040] Therefore, this invention can clean the hot low-separation oil filter without affecting the long-term stable operation of the process system, and at the same time solve the problem of erosion and wear of heavy oil pipelines caused by the discharge of hot low-separation oil containing catalyst.

[0041] To further optimize the system and facilitate the monitoring of the liquid level in the oil drain tank 5, a level gauge is installed. This gauge accurately measures the level of the hot low-temperature oil in the tank, allowing for the periodic discharge of this oil and preventing overflow. In practice, complementary field level gauges and remote level gauges are typically used. The field level gauge provides local, direct observation with high reliability and serves as the benchmark for calibrating the remote gauges. The remote level gauge transmits signals to the central control unit, enabling remote monitoring of the liquid level in the oil drain tank 5 and preventing overflow.

[0042] Further optimization is needed because hot low-part oil is a high-temperature, heavy oil product. When its oil vapor mixes with air (oxygen), it is highly susceptible to combustion and even explosion under certain concentration and temperature conditions. To prevent safety accidents, a nitrogen pressure control system is installed at the top of the drain tank 5. The nitrogen pressure control system includes a regulating valve and a pressure gauge to measure the pressure inside the drain tank 5. The regulating valve connects the drain tank 5, the nitrogen pipeline, and the flare. When the internal pressure of the drain tank 5 decreases, the regulating valve opens, allowing nitrogen to flow in and maintain the pressure inside the tank. When the internal pressure of the drain tank 5 becomes too high, the excess gas is discharged into the flare. Nitrogen pressure control is a mature existing technology, and will not be described in detail here.

[0043] To further optimize the process and improve the convenience of oil transportation, an oil discharge pump is installed on the oil pipeline. The oil discharge pump is a centrifugal pump, and a pressure detection device is installed on the outlet pipeline of the oil discharge pump.

[0044] To further optimize the process and prevent erosion of the oil pump by a small amount of catalyst particles in the oil sludge, a filter assembly for intercepting catalyst particles is installed on the oil pipeline between the oil storage tank 5 and the oil pump. Specifically, the filter assembly is a sintered metal filter or a basket filter.

[0045] To further optimize the process and avoid temporary oil draining needs of the hot low-separation oil filter during oil pump failure or cleaning of oil storage tank 5, a direct discharge pipeline between the hot low-separation oil filter and the heavy oil pipeline is retained: Specifically, the direct discharge pipeline and the oil drain pipeline are set up in parallel; the direct discharge pipeline is connected to the oil drain port of the low-separation oil filter, and the other end is connected to the heavy oil pipeline; and a control valve is installed on the direct discharge pipeline.

[0046] Specifically, the direct discharge pipeline, the drain pipeline, the drain port of the commonly used hot low-separation oil filter 3A, and the drain port of the spare hot low-separation oil filter 3B are connected by a cross joint. A first valve is installed on the drain pipeline, and a second valve is installed on the direct discharge pipeline. In case of emergency temporary draining via the direct discharge pipeline, the first valve is closed and the second valve is opened.

[0047] To further optimize and adapt to the automated operation of the process system, this embodiment sets the following:

[0048] Connect the aforementioned remote level gauge to the central control unit. The central control unit receives the level signal sent by the remote level gauge, which allows the operator to start or stop the oil pump according to the level in the oil storage tank 5.

[0049] The pressure detection device mentioned above is a pressure transmitter. The pressure transmitter is connected to the central control unit, which receives the pressure signal from the pressure transmitter and monitors the outlet pressure of the oil discharge pump to prevent the oil discharge pump from pressurizing or malfunctioning.

[0050] The specific steps for using this utility model are as follows:

[0051] Step 1: Filter Switching and Isolation

[0052] When the differential pressure of the commonly used hot low-pressure oil filter 3A reaches its upper limit, the operator opens the inlet and outlet manual valves of the standby hot low-pressure oil filter 3B to put it into operation and switch the process system to the standby hot low-pressure oil filter 3B; then, the inlet and outlet manual valves of the commonly used hot low-pressure oil filter 3A to be cleaned are closed to completely isolate it from the high-temperature and high-pressure process system.

[0053] Step 2: Depressurize and drain hot oil into oil storage tank 5

[0054] Confirm that the oil drain tank 5 has sufficient capacity, and drain the hot low-separation oil containing the catalyst from the isolated common hot low-separation oil filter 3A into the oil drain tank 5; maintain the inert environment inside the tank with nitrogen pressure control.

[0055] Step 3: Buffering and Settling within Oil Discharge Tank 5

[0056] After the hot, low-grade oil enters the discharge storage tank 5, its flow rate decreases sharply. Most of the solid catalyst particles settle to the bottom of the tank under gravity, forming a catalyst slurry. The oil in the upper part of the tank becomes relatively clean, and the catalyst content is significantly reduced.

[0057] The remote level gauge monitors the liquid level in the five oil storage tanks and transmits the level signal to the central control unit.

[0058] Step 4: Smooth Export of Clean Oil Products

[0059] When the liquid level in the oil storage tank 5 reaches a certain height, or after sufficient settling time, the operator will start the oil pump based on the liquid level signal received from the central control system to discharge the oil sludge (supernatant).

[0060] The pressure transmitter monitors the pump outlet pressure, and the pressure signal at the pump outlet is fed back to the central control unit to maintain the stable operation of the oil discharge pump and prevent the oil discharge pump from pressure buildup or abnormality.

[0061] Step 5: Reset and Backup

[0062] After the oil sludge (supernatant) in the oil storage tank 5 has been drained, turn off the oil pump;

[0063] Regularly clean the catalyst at the bottom of oil storage tank 5 to remove slag;

[0064] The emptied common hot low-temperature oil filter 3A is purged with nitrogen to remove residual oil, and then mechanically cleaned or the filter element is replaced to restore it to standby condition.

[0065] Direct-flow piping is only used for short periods of time in emergencies:

[0066] When the oil drain tank 5 needs maintenance or cleaning, or other emergency situations that prevent the oil drain tank 5 from working properly; or when the oil drain pump malfunctions and cannot be used; or other emergency situations that prevent the oil drain tank 5 from working properly.

[0067] Operating procedure: Close the first valve and open the second valve. The hot low-temperature oil in the hot low-temperature oil filter to be cleaned will be directly discharged into the heavy sludge pipeline.

[0068] Through the above specific implementation methods, this system achieves:

[0069] 1. By utilizing the buffering function of the oil discharge tank 5, the original operation mode of instantaneously and rapidly discharging hot, low-separation oil into the heavy oil pipeline was changed. This avoids the erosion and wear caused to the heavy oil pipeline by instantaneous high-flow-rate, high-solids-content discharge. At the same time, this creates conditions for subsequent stable, low-pressure transportation through equipment such as the oil discharge pump, greatly improving the stability of the entire filtration system.

[0070] At the same time, it reduces unplanned downtime of the process system caused by frequent maintenance due to wear and tear of heavy oil pipelines, thus improving the continuity and economy of the process system operation.

[0071] 2. Through the settling separation action of the oil storage tank 5, preliminary separation of oil and solids is achieved. The clear liquid at the top after settling can be transported to the heavy oil system, while the catalyst slurry enriched at the bottom can be centrally treated. This not only reduces the settling burden on downstream utility pipelines, but more importantly, the relatively clean oil separated has a higher recovery value, providing possibilities for subsequent material recovery and energy reuse, thereby reducing material and energy consumption and improving the economic efficiency of the unit's operation.

[0072] 3. Equipped with a liquid level gauge, nitrogen pressure control and pump outlet pressure monitoring device. The liquid level gauge can prevent the storage tank from overflowing; the nitrogen pressure control can ensure the safety of the operating environment; the pressure monitoring ensures the safety of pumping and further ensures the long-term safe and stable operation of the filtration system.

[0073] The preferred embodiments of this utility model are not intended to limit the scope of protection of this utility model. Therefore, all equivalent changes made to the structure, shape, and principle of this utility model should be included within the scope of protection of this utility model.

Claims

1. A fluidized bed hot low-pressure oil separation filtration system, comprising a hot low-pressure oil separation filter (3) connected to the oil outlet of a hot low-pressure separator (22), characterized in that: It also includes an oil drain tank (5); The inlet of the oil storage tank (5) is connected to the outlet of the hot low-temperature oil filter (3) through an oil discharge pipeline; The outlet of the oil storage tank (5) is connected to the heavy waste oil pipeline through the oil pipeline.

2. The fluidized bed hot low-separation oil filtration system according to claim 1, characterized in that, The oil discharge tank (5) is equipped with a level gauge.

3. The fluidized bed hot low-separation oil filtration system according to claim 1, characterized in that, The top of the oil drain tank (5) is equipped with nitrogen pressure control.

4. The fluidized bed hot low-separation oil filtration system according to claim 1, characterized in that, An oil pump is installed on the oil pipeline.

5. The fluidized bed hot low-separation oil filtration system according to claim 4, characterized in that, A pressure detection device is installed on the outlet pipeline of the oil pump.

6. The fluidized bed hot low-separation oil filtration system according to claim 5, characterized in that, The oil pipeline is also equipped with a filter assembly for intercepting catalyst particles, which is located between the oil discharge tank (5) and the oil discharge pump.

7. The fluidized bed hot low-separation oil filtration system according to claim 6, characterized in that, The filter assembly is a sintered metal filter or a basket filter.

8. The fluidized bed hot low-separation oil filtration system according to claim 1, characterized in that, This also includes direct-flow pipes; The straight discharge pipeline and the oil discharge pipeline are arranged in parallel; One end of the direct discharge pipeline is connected to the oil outlet of the hot low-separation oil filter (3), and the other end is connected to the heavy sludge oil pipeline; Furthermore, a control valve is installed on the direct discharge pipeline.

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