A system for the regeneration of a welded plate heat exchanger

Abstract

The utility model discloses a kind of welding plate heat exchanger burning coke regeneration systems, it is related to welding plate heat exchanger regeneration process field, including heating furnace, compressor, liquid separator, cold exchange equipment and plate heat exchanger to be burned, plate heat exchanger to be burned is provided with cold end entrance and hot end entrance, heating furnace outlet is connected cold end entrance by pipeline one, cold end outlet is connected hot end entrance by pipeline two, hot end outlet is connected cold exchange equipment by pipeline three, cold exchange equipment is connected the middle part entrance of liquid separator by pipeline four, liquid separator gas phase outlet is connected compressor by pipeline five, compressor is connected heating furnace entrance by pipeline six, all pipeline forms burning coke gas circulation loop, cross line is provided between pipeline three and pipeline six, multiple valves are provided on cross line, nitrogen supplement pipeline is externally connected to compressor, air injection pipeline, which is installed with air regulating valve, is externally connected to pipeline five.The utility model can make that burning coke temperature is flexibly controllable, realize low-cost plate burning coke regeneration.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of welding plate heat exchanger regeneration process, and specifically relates to a welding plate heat exchanger coke burning regeneration system. BACKGROUND

[0002] Welding plate heat exchanger has many advantages such as small volume, large heat exchange area, high heat exchange efficiency, is usually used in high-temperature, high-pressure, large heat exchange capacity chemical production process, and the general hot end temperature is above 300 DEG C. With the increase of use time, carbon deposition, ammonium salt, gum and the like gradually accumulate on the plate, and the plate exchange pressure difference gradually rises, which affects the production load and safe and stable operation of the device, in order to ensure the efficient operation of the system, the welding plate heat exchanger needs to be regenerated. Generally, the possible reasons for the pressure difference rising are analyzed from the process environment used, if the conditions for generating ammonium salt exist in the system, chemical cleaning is preferred, and then the coke burning process is used for regeneration. The commonly used regeneration methods at present are: chemical cleaning method, steam-air coke burning method, plate heat exchanger-catalyst combined coke burning method. The above-mentioned methods have high regeneration cost, large construction workload and complicated process, and a large amount of manpower and material resources are consumed, and the economy and reliability are poor.

[0003] Since ammonium salt crystals may exist in the system, if chemical cleaning or steam-air combined coke burning method is used, the risk of plate exchange corrosion leakage will be greatly increased, and the combined catalyst coke burning has the problems of catalyst damage and incomplete coke burning. In addition, the steam-air coke burning method needs a large amount of direct discharge air, which has potential environmental pollution risk, and the plate exchange-catalyst combined coke burning method has much more carbon deposition on the catalyst than on the plate, and the coke burning is more intense, so the water content in the circulating coke burning gas must be strictly controlled through the drying tower, otherwise the catalyst will be irreversibly damaged.

[0004] The Chinese patent document with publication number CN202070342U and publication date of December 14, 2011 discloses a catalyst negative pressure regeneration device, which comprises an inlet and outlet material heat exchanger, a reaction heating furnace, a fixed bed reactor, a reaction product post-cooler, a coke burning gas separation tank and a circulating gas compressor, the inlet and outlet material heat exchanger, the reaction product post-cooler, the coke burning gas separation tank and the circulating gas compressor are sequentially connected in series into a circulating loop through pipelines, an injector is arranged on the pipeline between the coke burning gas separation tank and the circulating gas compressor, and the inlet and outlet material heat exchanger, the reaction heating furnace and the fixed bed reactor are sequentially connected in series into another circulating loop through pipelines. The utility model has the advantages of short nitrogen purging replacement time, short coke burning period and low device energy consumption.

[0005] However, the above technical scheme is used for catalyst regeneration, and negative pressure is intermittently used to deeply analyze the residual oil gas in the catalyst, but there are problems of oil gas direct discharge into the atmosphere to pollute the environment and noise pollution of vacuumizing power steam. The utility model discloses a kind of plate welder heat exchanger coke burning regeneration systems.

[0006] To solve the technical problems existing in the prior art, the utility model provides a kind of plate welder heat exchanger coke burning regeneration system.The system greatly simplifies coke burning process, can flexibly adjust temporary piping mode to adapt to different coke burning needs, coke burning temperature and oxygen content are highly controllable, coke burning process is safe and controlled, the design of coke burning gas into and out of plate exchange cross line can effectively improve the upper limit of coke burning temperature, while ensuring that plate exchange cold end outlet pipeline equipment is not overheated, coke burning is complete, the whole coke burning process adopts closed discharge, in line with the thinking of green industrial development.

[0007] The utility model realizes by the following technical scheme:

[0008] A kind of plate welder heat exchanger coke burning regeneration system, including heating furnace, compressor, liquid separator, cold exchange equipment and plate heat exchanger to be burned, the plate heat exchanger to be burned is the plate heat exchanger with dehydrogenation, coking, carbonized colloidal substance inside, the plate heat exchanger to be burned is provided with cold end inlet, cold end outlet, hot end inlet and hot end outlet, the cold end inlet of plate heat exchanger to be burned is connected with the heating furnace outlet by pipeline one, the hot end inlet of plate heat exchanger to be burned is connected with the cold end outlet of plate heat exchanger to be burned by pipeline two, the hot end outlet of plate heat exchanger to be burned is connected with the inlet of cold exchange equipment by pipeline three, the outlet of cold exchange equipment is connected with the middle part inlet of liquid separator by pipeline four, the gas phase outlet of liquid separator is connected with the inlet of compressor by pipeline five, the outlet of compressor is connected with the inlet of heating furnace by pipeline six, all pipelines form coke burning gas circulation loop, cross line is arranged between pipeline three and pipeline six, a plurality of valves are arranged on the cross line, the compressor is connected with nitrogen supplement pipeline for providing nitrogen to stabilize system gas circulation, the pipeline five is connected with air injection pipeline, and air regulating valve for adjusting air content is arranged on the air injection pipeline.

[0009] Dryer is arranged on the pipeline five, the inlet of the dryer is connected with the gas phase outlet of liquid separator, and the outlet of the dryer is connected with the inlet of compressor.

[0010] Oxygen table for monitoring oxygen content in circulating gas is arranged on the pipeline six and pipeline two.

[0011] Oxygen table for monitoring oxygen content in circulating gas is arranged on the pipeline six and pipeline three.

[0012] The plate heat exchanger to be burned is the plate heat exchanger to be burned without ammonium salt generation environment.

[0013] Safety valve for discharging part of circulating gas to vent system before coke burning is arranged on the top of liquid separator.

[0014] The heating furnace is an electric heating furnace or a microwave heating furnace.

[0015] The valve is provided with two.

[0016] Temperature sensors are arranged on the pipeline one, the pipeline two and the pipeline three respectively.

[0017] Pressure gauges are arranged on the pipeline two and the air injection pipeline.

[0018] The beneficial effects of the utility model mainly manifest in the following aspects:

[0019] 1. The utility model can utilize the equipment pipeline of the original system to the maximum extent, has small technical reconstruction construction quantity, simple operation and control, keeps the various parameters and initial performance of the plate exchanger after burning out, greatly improves the heat exchange efficiency and system processing capacity, effectively improves the upper limit of the burning out temperature through the design of the cross line, simultaneously ensures that the plate exchanger cold end outlet pipeline equipment is not overheated, makes the compressor outlet part of the circulating gas directly enter the second stage burning out gas, thereby controls the temperature of the second stage burning out gas to the plate exchanger equipment to be less than 200 DEG C, simultaneously can burn out completely, the whole burning out process adopts closed discharge, and meets the idea of green industrial development.

[0020] 2. The utility model removes the moisture in the circulating gas before the compressor inlet through the dryer, reduces the damage of the compressor caused by the moisture, and ensures that the system gas is dry before entering the compressor, avoids that the moisture in the gas causes equipment damage and corrosion.

[0021] 3. The utility model is provided with the oxygen table for monitoring the oxygen content in the circulating gas on the pipeline six and the pipeline two or the pipeline six and the pipeline three, can monitor the oxygen content of the circulating gas before and after burning out, ensures that the oxygen level is in the safe range in the burning out regeneration process, also can be used for adjusting the working state of the heating furnace and other equipment, and optimizes the energy efficiency of the whole burning out regeneration process.

[0022] 4. The utility model is the plate heat exchanger to be burned out, which does not exist in the ammonium salt generation environment, effectively avoids the harm of the corrosive gas and the deposit produced by the ammonium salt decomposition to the equipment, and ensures that the system is safer and more reliable in the burning out process.

[0023] 5. The whole burning out process adopts closed discharge, part of the circulating gas before burning out and a small amount of waste gas after burning out are discharged to the venting system through the safety valve, there is no environmental pollution problem, and the environmental friendliness of the system is improved.

[0024] 6. The utility model can select the heating furnace flexibly according to actual needs, enhances the applicability and flexibility of the system, and improves the energy efficiency and energy saving effect. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The system is a schematic diagram.

[0026] Marked in the figure: 1, heating furnace; 2, to be burned plate heat exchanger; 3, cold end inlet; 4, cold end outlet; 5, hot end inlet; 6, hot end outlet; 7, cooling equipment; 8, liquid separation tank; 9, compressor; 10, pipeline one; 11, pipeline two; 12, pipeline three; 13, pipeline four; 14, pipeline five; 15, pipeline six; 16, nitrogen supplement pipeline; 17, oxygen table; 18, air injection pipeline; 19, air regulating valve; 20, cross line; 21, valve. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the utility model will be described clearly and completely below, obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model

[0028] Embodiment 1

[0029] As the most basic embodiment of the utility model, referring to Figure 1 A plate heat exchanger burning and regenerating system, comprising a heating furnace 1, a compressor 9, a liquid separation tank 8, a cold exchange equipment and a to be burned plate heat exchanger 2, the to be burned plate heat exchanger 2 is a plate heat exchanger with dehydrogenation, coking and carbonized colloid inside, the to be burned plate heat exchanger 2 is provided with a cold end inlet 3, a cold end outlet 4, a hot end inlet 5 and a hot end outlet 6, the outlet of the heating furnace 1 is connected with the cold end inlet 3 of the to be burned plate heat exchanger 2 through pipeline one 10, the cold end outlet 4 of the to be burned plate heat exchanger 2 is connected with the hot end inlet 5 of the to be burned plate heat exchanger 2 through pipeline two 11, the hot end outlet 6 of the to be burned plate heat exchanger 2 is connected with the inlet of the cold exchange equipment through pipeline three 12, the outlet of the cold exchange equipment is connected with the middle inlet of the liquid separation tank 8 through pipeline four 13, the gas phase outlet of the liquid separation tank 8 is connected with the inlet of the compressor 9 through pipeline five 14, the outlet of the compressor 9 is connected with the inlet of the heating furnace 1 through pipeline six 15, all the pipelines form a burning gas circulating loop, a cross line 20 is arranged between the pipeline three 12 and the pipeline six 15, a plurality of valves 21 are arranged on the cross line 20, the compressor 9 is externally connected with a nitrogen supplement pipeline 16 for providing nitrogen to stabilize the system gas circulation, the pipeline five 14 is externally connected with an air injection pipeline 18, and the air injection pipeline 18 is provided with an air regulating valve 19 for adjusting the content of injected air.

[0030] In the embodiment, the reactor is disconnected from the system, and nitrogen sealing protection is performed separately; the pipelines unrelated to the charring system are all isolated by blanking plates, and it is ensured that the system stripping time before charring is not less than 4 hours, and the liquid in each low point is discharged. The short sections of the cold end inlet 3 and the outlet and the hot end inlet 5 of the plate heat exchanger are removed, and temporary pipelines are added to connect the compressor 9 outlet circulating gas to the plate exchanger cold end outlet 4 to the heating furnace 1 pipeline, connect the heating furnace 1 outlet to the plate exchanger reactor inlet pipeline to the plate exchanger cold end inlet 3, and connect the plate exchanger cold end outlet 4 and the hot end inlet 5, which can maximize the use of the original system equipment pipeline, has small technical transformation construction quantity, simple operation and control, ensures the gas circulation stability and regeneration effect in the charring process, and keeps the plate exchanger parameters flat after charring, greatly improves the heat exchange efficiency and system processing capacity, and the design of the charring gas in and out of the plate exchanger cross line 20 can effectively improve the upper limit of the charring temperature, while ensuring that the plate exchanger cold end outlet 4 pipeline equipment is not overheated, the charring is complete, and the whole charring process adopts closed discharge, which meets the idea of green industrial development.

[0031] Embodiment 2

[0032] As another preferable embodiment of the utility model, the embodiment is a further detailed supplement and elaboration of the technical scheme of the utility model on the basis of the above-mentioned embodiment 1, and refers to Figure 1 In the embodiment, the pipeline five 14 is provided with a dryer, the dryer inlet is connected with the gas phase outlet of the liquid separation tank 8, and the dryer outlet is connected with the inlet of the compressor 9; the pipeline six 15 and the pipeline two 11 are provided with an oxygen table 17 for monitoring the oxygen content in the circulating gas.

[0033] In the embodiment, the dryer can reduce water vapor in the gas, reduce the burden of the compressor 9 during operation, prevent corrosion and equipment failure caused by too high gas humidity, thereby prolonging the service life of the system equipment, in addition, the oxygen table 17 for monitoring the oxygen content in the circulating gas is arranged on the pipeline six 15 and the pipeline two 11, which can monitor the oxygen concentration in the circulating gas in real time, and can effectively detect the change of the oxygen content in the circulating gas before and after charring.

[0034] Embodiment 3

[0035] As the best embodiment of the utility model, the embodiment discloses a welding plate heat exchanger charring regeneration system, comprising a heating furnace 1, a compressor 9, a liquid separator 8, a cold exchange equipment and a plate heat exchanger 2 to be charred, the plate heat exchanger 2 to be charred is a plate heat exchanger with dehydrogenation, coking and carbonized colloid inside, the plate heat exchanger 2 to be charred is provided with a cold end inlet 3, a cold end outlet 4, a hot end inlet 5 and a hot end outlet 6, the outlet of the heating furnace 1 is connected with the cold end inlet 3 of the plate heat exchanger 2 to be charred through pipeline one 10, the cold end outlet 4 of the plate heat exchanger 2 to be charred is connected with the hot end inlet 5 of the plate heat exchanger 2 to be charred through pipeline two 11, the hot end outlet 6 of the plate heat exchanger 2 to be charred is connected with the inlet of the cold exchange equipment through pipeline three 12, the outlet of the cold exchange equipment is connected with the middle inlet of the liquid separator 8 through pipeline four 13, the gas phase outlet of the liquid separator 8 is connected with the inlet of the compressor 9 through pipeline five 14, the outlet of the compressor 9 is connected with the inlet of the heating furnace 1 through pipeline six 15, all pipelines form a charring gas circulation loop, a cross line 20 is arranged between the pipeline three 12 and the pipeline six 15, a double valve is arranged on the cross line 20, the compressor 9 is externally connected with a nitrogen supplement pipeline 16 for providing nitrogen to stabilize the gas circulation of the system, the pipeline five 14 is externally connected with an air injection pipeline 18, and an air adjusting valve 19 for adjusting the content of injected air is arranged on the air injection pipeline 18.

[0036] A dryer is arranged on the pipeline five 14, the inlet of the dryer is connected with the gas phase outlet of the liquid separator 8, and the outlet of the dryer is connected with the inlet of the compressor 9.

[0037] An oxygen table 17 for monitoring the oxygen content in the circulating gas is arranged on the pipeline six 15 and the pipeline two 11, and the plate heat exchanger 2 to be charred is a plate heat exchanger to be charred without an ammonium salt generating environment.

[0038] A safety valve for discharging part of circulating gas to a venting system before charring is arranged on the top of the liquid separator 8.

[0039] The heating furnace 1 is an electric heating furnace.

[0040] Temperature sensors are arranged on the pipeline one 10, the pipeline two 11 and the pipeline three 12 respectively.

[0041] Pressure tables are arranged on the pipeline two 11 and the air injection pipeline 18.

[0042] When the system is in operation, nitrogen is supplemented through the nitrogen supplement pipeline 16, and the system pressure is determined according to the nitrogen working condition design value of the compressor 9. The compressor 9 is started to establish gas circulation, and the system is checked for leakage. Then the heating furnace 1 is started to heat, and after reaching 120℃, constant temperature dehydration is carried out. After confirming that the system is dry, the temperature is continuously increased to 200℃. The air injection valve is slowly adjusted to adjust the oxygen content of the system. After the system pressure starts to rise, part of the circulating gas is discharged through the top safety valve of the liquid separation tank 8 to the venting system, so as to maintain a suitable system pressure. Temporary oxygen tables are installed in the pipeline six 15 from the outlet of the compressor 9 to the inlet of the heating furnace 1 and the pipeline two 11 from the outlet of the cold end of the plate heat exchanger 4 to the inlet of the hot end, which are used to monitor the oxygen content of the circulating gas before and after coking. When the values of the two oxygen tables are the same and stable, it indicates that the current working condition is coking completed, and the temperature and oxygen content are continuously increased or the coking is terminated. The liquid separation tank 8 includes one or more stages of gas-liquid separation equipment, which is used to remove the liquid phase components in the circulating coking gas and recover the gas phase components. The material in the hot end outlet 6 of the plate heat exchanger is cooled by the cold exchange equipment, and then enters the middle part of the liquid separation tank 8. The gas phase part passes through the top defoaming net to remove liquid drops, and then enters the front cold exchange equipment of the next stage of liquid separation tank 8. Until the temperature of the gas phase at the top is not more than 40℃, it enters the suction inlet of the compressor 9. The liquid phase at the bottom is discharged through a closed discharge system in the early stage of coking, and is discharged through an open discharge system in the later stage of coking to measure and remove the water content. The pipeline between the bottom of the liquid separation tank 8 and the downstream process system must be isolated by a blind plate. The pipeline from the top safety valve or other closed discharge system to the venting system is used as a coking tail gas discharge port.

[0043] The circulating gas used in the plate heat exchanger coking regeneration process is a mixture of nitrogen and air. In the embodiment, the oxygen content control range is 0% to 1%, and the oxygen content is gradually and slowly increased according to the coking progress. In the embodiment, the circulating gas enters the heating furnace 1 for heating, so that the temperature entering the plate heat exchanger is increased to 400℃ finally. The outlet temperature of the heating furnace 1 should be strictly increased in stages according to the coking temperature curve, and at the same time, the upper limit of the temperature resistance of the pipeline equipment should be considered. Over-temperature is strictly prohibited. The temperature of the one-stage coking gas coming out of the plate heat exchanger is slightly increased. By adjusting the opening degree of the valve 21 on the cross pipeline 20, part of the circulating gas at the outlet of the compressor 9 directly enters the two-stage coking gas, so as to control the temperature of the two-stage coking gas to the cold exchange equipment to be not more than 200℃, and to ensure that the inlet of the air cooler is not over-temperature.

[0044] The whole coking process in the embodiment adopts closed discharge, which can not only improve the environmental protection and safety of the system, but also has accurate temperature control, can effectively reduce energy waste, improves the working efficiency and energy utilization efficiency of the coking regeneration system, and effectively guarantees the safety and long-term stable operation of the equipment. The embodiment can maximize the use of the equipment pipelines of the original system, has small technical improvement construction quantity, simple operation and control, and the various parameters of the plate exchanger after coking are flat with the initial performance, greatly improves the heat exchange efficiency and system processing capacity, and the coking scheme cost of the plate exchanger manufacturer is about 3 million yuan / time and takes 20 days; the cost of the scheme is 100,000 yuan / time and takes 14 days, and the advantages are obvious.

Claims

1. A system for coke burning regeneration of a plate heat exchanger, comprising a heating furnace (1), a compressor (9), a liquid separator (8) and a cold exchange device, characterized in that: Also included is a to-be-coked plate heat exchanger (2), which is a plate heat exchanger with dehydrogenation, coking and carbonized colloidal substances inside, and is provided with a cold end inlet (3), a cold end outlet (4), a hot end inlet (5) and a hot end outlet (6). The outlet of the heating furnace (1) is connected with the cold end inlet (3) of the to-be-coked plate heat exchanger (2) through pipeline one (10), the cold end outlet (4) of the to-be-coked plate heat exchanger (2) is connected with the hot end inlet (5) of the to-be-coked plate heat exchanger (2) through pipeline two (11), the hot end outlet (6) of the to-be-coked plate heat exchanger (2) is connected with the inlet of the cold exchange equipment through pipeline three (12), the outlet of the cold exchange equipment is connected with the middle inlet of the liquid separation tank (8) through pipeline four (13), the gas phase outlet of the liquid separation tank (8) is connected with the inlet of the compressor (9) through pipeline five (14), the outlet of the compressor (9) is connected with the inlet of the heating furnace (1) through pipeline six (15), all the pipelines form a coking gas circulation loop, a cross line (20) is arranged between the pipeline three (12) and the pipeline six (15), a plurality of valves (21) are arranged on the cross line (20), the compressor (9) is externally connected with a nitrogen supplement pipeline (16) for providing nitrogen to stabilize the gas circulation of the system, and the pipeline five (14) is externally connected with an air injection pipeline (18), and an air adjusting valve (19) for adjusting the content of injected air is arranged on the air injection pipeline (18).

2. A system for coke burning and regeneration of a plate heat exchanger according to claim 1, characterized in that: A dryer is arranged on the pipeline five (14), the inlet of the dryer is connected with the gas phase outlet of the liquid separation tank (8), and the outlet of the dryer is connected with the inlet of the compressor (9).

3. A system for coke burning and regeneration of a plate heat exchanger according to claim 2, characterized in that: An oxygen table (17) for monitoring the oxygen content in the circulating gas is arranged on the pipeline six (15) and the pipeline two (11).

4. A system for coke burning and regeneration of a plate heat exchanger according to claim 2, characterized in that: An oxygen table (17) for monitoring the oxygen content in the circulating gas is arranged on the pipeline six (15) and the pipeline three (12).

5. A system for coke burning and regeneration of a plate heat exchanger according to claim 3 or 4, characterized in that: The to-be-coked plate heat exchanger (2) is a to-be-coked heat exchanger without an ammonium salt generating environment.

6. A system for coke burning and regeneration of a plate heat exchanger according to claim 5, characterized in that: A safety valve for discharging part of the circulating gas to a venting system before coking is arranged at the top of the liquid separation tank (8).

7. A system for the regeneration of a fouled plate heat exchanger according to claim 6, wherein: The heating furnace (1) is an electric heating furnace or a microwave heating furnace.

8. A system for coke burning and regeneration of a plate heat exchanger according to claim 7, characterized in that: The valve (21) is provided with two.

9. A system for the regeneration of a fouled plate heat exchanger according to claim 8, wherein: Temperature sensors are arranged on the pipeline one (10), the pipeline two (11) and the pipeline three (12) respectively.

10. A system for the regeneration of a fouled plate heat exchanger according to claim 9, wherein: Pressure gauges are arranged on the pipeline two (11) and the air injection pipeline (18).

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