Organic wet slurry low-temperature damp and hot coalification integrated reactor and system

Abstract

The invention discloses an organic wet slurry low-temperature damp and hot coalification integrated reactor and system, and relates to the technical field of organic solid waste treatment. The system comprises a conveying system, a plurality of integrated reactor systems connected in parallel, a cooler, a solid-liquid separator and a central control unit. The integrated reactor system comprises an integrated reactor, a heater, a sensing unit and a reactor control unit. The integrated reactor adopts a unique inner and outer double-pipe layer design, and a heat exchange section, a heating section and a reaction section are sequentially formed, so that the integration of countercurrent flow heat exchange, heating and reaction is realized; a double-layer stirring wall scraper and a plurality of groups of ultrasonic vibrators are arranged in the heat exchanger, so that scales and cokes on a heat transfer surface can be removed on line; and through cooperative intelligent control of the reactor control unit and the central control unit, operation parameters and cleaning strategies are adjusted in real time. The industrial problems that in the traditional process, equipment is prone to being blocked, the heat transfer efficiency is low, and operation is unstable are solved, and efficient and long-period stable operation of coalification treatment of the organic wet slurry is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic solid waste resource processing, in particular to a low-temperature wet-heat coalification integrated reactor and system for treating high-moisture-content, easy-scaling and easy-coking organic wet slurry. BACKGROUND

[0002] The organic wet slurry in the environmental protection industry, such as kitchen garbage, kitchen waste, biogas residue, sludge and the like, after pretreatment, forms a slurry material, which is complex in composition, high in moisture content (usually 70%-90%), and contains oil, protein, carbohydrate and other components that are easy to adhere, coking and scaling in the heat treatment process. The low-temperature wet-heat coalification treatment of such materials refers to the reaction under a certain temperature (usually 180-250℃) and pressure after adding a catalyst, so that the organic matter therein undergoes decarboxylation, hydrolysis, polycondensation and other reactions, and is finally converted into carbon-based solid coalification and waste water rich in organic matter.

[0003] The core equipment of the process includes a heat exchanger, a heater and a reactor. In the traditional scheme, the three are connected in series through pipelines. However, the material is easy to scale on the heat transfer surface of the heat exchanger and the heater, and to coking in the inner wall of the reactor and the pipeline, resulting in increased system resistance and sharply decreased heat transfer efficiency, and ultimately forced shutdown for cleaning. Frequent maintenance not only has high cost, but also causes the system to be unable to run stably for a long time. Therefore, developing an integrated equipment and system that can be online anti-blocking, self-cleaning and stably and efficiently operated has become a technical problem in the field. SUMMARY

[0004] The present application aims to overcome the shortcomings of the prior art and provide a low-temperature wet-heat coalification integrated reactor and system for organic wet slurry, which integrates the functions of heat exchange, heating and reaction in a single equipment, and integrates online mechanical wall scraping and ultrasonic descaling device, thereby fundamentally solving the problems of easy blocking of equipment, rapid attenuation of heat transfer efficiency and unstable operation in the traditional process.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] A low-temperature wet-heat coalification integrated reactor and system for organic wet slurry, comprising a conveying system, a plurality of integrated reactor systems arranged in parallel, a cooler, a solid-liquid separator and a central control unit. The central control unit centrally monitors and coordinates the operation of the entire system. Each integrated reactor system comprises an integrated reactor, a heater, a liquid level sensor, a pressure sensor, a temperature sensor, a reactor control unit, a feed control valve and a discharge control valve, and has the ability of independent operation and control.

[0007] The integrated reactor adopts a double-pipe layer structure. The annular gap between the outer pipe layer and the inner pipe layer forms a first flow channel, and the cavity inside the inner pipe layer forms a second flow channel. The equipment is divided into a heat exchange section, a heating section, and a reaction section along the axial direction. The cold material enters the second flow channel (inner pipe), is preheated by heat exchange with the hot material in the first flow channel (outer pipe) in the heat exchange section, is heated to the reaction temperature by the external heating layer in the heating section, and then completes the coalification reaction in the reaction section. The hot material after the reaction returns to the first flow channel, flows in the opposite direction, and exchanges heat with the cold material in the second flow channel, and is finally discharged. This counter-flow heat exchange design greatly recovers the reaction heat and improves energy efficiency.

[0008] The integrated reactor is designed in terms of structure and size to optimize performance: the length-diameter ratio (length to outer diameter of the reactor) of the heat exchange section is designed to be 6:1 to 12:1, which ensures sufficient heat exchange travel and heat exchange area between cold and hot materials, thereby achieving sufficient preheating; the length-diameter ratio (length to outer diameter of the reactor) of the heating section is designed to be 3:1 to 6:1, which ensures heating efficiency while avoiding pressure loss and manufacturing difficulties caused by excessive length of the equipment; the inner pipe wall extends from the heat exchange section to the heating section and extends into 1 / 3 to 1 / 2 of the length of the reaction section, which ensures that the material is sufficiently and uniformly heated before entering the reaction section and can be stably introduced into the reaction section, preventing flow short circuiting.

[0009] Further, the length ratio of the heat exchange section to the heating section is optimized to be 2:1 to 4:1, which is the optimal interval based on a large amount of heat energy calculation and experiments, and can most effectively balance the preheating demand and heating load. The length of the reaction section satisfies the following relationship: L > K * D² / d, where L is the length of the reaction section, D is the diameter of the outer pipe wall, d is the diameter of the inner pipe wall, and K is a coefficient determined by the reaction kinetics characteristics of the material. This relationship ensures that the material has sufficient residence time in the reaction section to complete the coalification reaction. The heating layer simultaneously covers the corresponding outer pipe walls of the heating section and the reaction section, which aims to provide a continuous and stable heat source for the heating and temperature maintenance reaction of the material, reducing heat loss.

[0010] To address the problem of coking and fouling, the integrated reactor is also provided with a double-layer stirring and wall scraping device, a magnetic drive stirring motor, and multiple ultrasonic transducers; the double-layer stirring and wall scraping device includes a first wall scraping assembly arranged on the inner and outer sides of the inner pipe wall, and a second wall scraping assembly arranged on the inner walls of the heating section and the reaction section region, which is driven by a magnetic motor and has scraping arms provided with scraping plates, which can simultaneously clean the inner and outer walls of the inner pipe and the inner walls of the outer pipe in the heating section and the reaction section region. The ultrasonic transducers are arranged in groups on the walls of the integrated reactor in the slag discharge port region, the heat exchange section near the heating section, the middle of the heating section, and the middle of the reaction section, which are key positions prone to deposition and fouling, such as the slag discharge port, the interface near the heating section, and the middle of each section, and can online break and peel off the scale layer through cavitation effect.

[0011] The reactor control unit is a local controller of a single reactor system, realizing closed-loop control of liquid level, temperature, and pressure. Its control logic includes: adjusting the inlet and outlet valves according to the liquid level linkage to maintain material balance; adjusting the heater power according to the temperature feedback to maintain the reaction temperature; monitoring pressure abnormalities and starting safety interlocking, while uploading data to the central control unit; specifically: receiving the signal of the liquid level sensor, when the liquid level is higher than the first set value, controlling the inlet control valve to reduce the opening or close, and controlling the outlet control valve to increase the opening or open; when the liquid level is lower than the second set value, the opposite control is performed; receiving the signal of the temperature sensor, controlling the output power of the heater or the flow of the heating medium to maintain the set temperature; receiving the signal of the pressure sensor, when the pressure exceeds the safety range, performing shutdown or pressure relief protection operation, and uploading the signal to the central control unit.

[0012] The central control unit is the total control core of the whole system, which performs the following functions: according to the total processing capacity demand set by the system and the rated processing capacity of each integrated reactor system, the number of integrated reactors that need to be started or stopped is calculated and decided to achieve the optimal energy efficiency; receiving the real-time running data (such as temperature, pressure, flow) uploaded by each reactor control unit, and dynamically calculating the real-time heat transfer coefficient (K value) of each reactor based on the temperature difference and flow of the material import and export; comparing the calculated heat transfer coefficient with the set threshold value or initial value, if it is found that the heat transfer efficiency of a certain reactor decreases, the control unit of the reactor system is coordinated to adjust the rotation speed, running time and interval period of the double-layer stirring wall scraper, and / or adjust the working frequency and start-stop period of the ultrasonic vibrator to restore its heat transfer performance; monitoring the pressure balance and material distribution of the whole system to ensure and contact the stability of the system operation.

[0013] The preferred integrated reactor adopts vertical installation by default; if a limiting and fixed reinforcing structure is added at the bottom of the double-layer stirring wall scraper, the reactor can also be suitable for horizontal installation, but vertical installation is still preferred.

[0014] The preferred integrated reactor is provided with inner and outer double pipe layers, the outer diameter ranges from 250 to 800 mm, and the total length ranges from 3 to 12 m; matched with the double-layer stirring wall scraper, better strength, stability and space adaptation effect can be realized. In some occasions with low hardness of coking and scaling, after further optimization, multiple pipe layers can be used, but it is not recommended that the number of pipe layers exceeds 4.

[0015] The application also provides a processing process using the above-mentioned system, the steps of which include: (1) The central control unit controls the conveying system to distribute the pretreated organic wet slurry to one or more parallel integrated reactor systems according to the set total processing capacity; (2) The organic wet slurry first enters the second flow channel of the integrated reactor, and is preheated by heat exchange with the hot material in the first flow channel in the heat exchange section; then enters the heating section and is indirectly heated to the reaction temperature by the heating layer; and then enters the reaction section for heat preservation and pressure maintaining reaction; The reacted material is folded back into the first flow channel, sequentially flows through the reaction section, the heating section and the heat exchange section, and is cooled by heat exchange with the cold material in the second flow channel, and then is discharged through the discharge control valve; During the whole process, the reactor control unit adjusts the working states of the feed valve, the discharge valve and the heater in real time according to the liquid level, temperature and pressure signals, and controls the intermittent or continuous operation of the double-layer stirring wall scraper and the ultrasonic vibrator to prevent fouling and coking and maintain the heat transfer efficiency; (3) The materials discharged from the integrated reactor systems are collected and then enter the cooler for final cooling, and then enter the solid-liquid separator to be separated into solid coal products and liquid waste water, which are subjected to subsequent treatment respectively.

[0016] Compared with the prior art, the present application has the following advantages:

[0017] (1) High integration, eliminating pipe blockage: integrating the functions of heat exchange, heating and reaction in one, eliminating the connecting pipes between equipment, and fundamentally avoiding the risk of pipe blockage.

[0018] (2) Structure optimization, significant efficiency: through specific length-diameter ratio, length ratio and structure design, the heat transfer and reaction process are optimized, ensuring sufficient preheating, uniform heating and sufficient reaction time of the material, and high energy efficiency.

[0019] (3) Online cleaning, long-term stability: the combination of mechanical wall scraping and ultrasonic technology realizes online continuous cleaning of the heat transfer surface, effectively inhibits the formation of scale layer, ensures the long-term stability of heat transfer efficiency and long-period operation of the equipment.

[0020] (4) Intelligent control, high efficiency and energy saving: adopting the mode of combining distributed control (reactor control unit) with centralized management (central control unit), the system can adaptively adjust the operating parameters, optimize energy distribution, and realize precise isolation and system reconstruction in case of failure, with high reliability and intelligent degree.

[0021] (5) Modular design, flexible expansion: the design of parallel operation of multiple integrated reactor systems makes the system processing capacity flexible to adjust, easy to maintain and expand. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1is the process flow chart of the present application. Wherein 1-conveying pump, 2-integrated reactor, 3-heater, 4-cooler, 5-solid-liquid separator; 6-central control unit, L-liquid level sensing unit, P-pressure sensing unit, T-temperature sensing unit, C-reactor control unit, IN feed control valve, OU discharge control valve, (n is the nth integrated reactor).

[0023] Figure 2 is the structural schematic diagram of the integrated reactor of the present application: Wherein I-outer tube layer, II-inner tube layer, III-heating layer, IV-double layer stirring scraper, V-inner tube wall, VI-outer tube wall, VII-heating layer tube wall, VIII-magnetic stirring motor, IX-heat exchange section, X-heating section, XI-reaction section, XII-ultrasonic wave guide head, XIII-feeding port, XIV-discharge port, XV-heating medium inlet, XVI-heating medium outlet, XVII-discharge port.

[0024] Figure 3 is the cross-sectional top view of Figure 2 .

[0025] Figure label: 1-conveying system; 2-integrated reactor; 201-outer tube layer; 202-inner tube layer; 203-heating layer; 204-double layer stirring scraper; 205-inner tube wall; 206-outer tube wall; 207-heating layer tube wall; 208-magnetic stirring motor; 209-heat exchange section; 210-heating section; 211-reaction section; 212-ultrasonic wave transducer; 213-feeding port; 214-discharge port; 215-heating medium inlet; 216-heating medium outlet; 217-discharge port; 3-heater; 4-cooler; 5-solid-liquid separator; 6-central control unit; L-liquid level sensor; P-pressure sensor; T-temperature sensor; C-reactor control unit; IN-feed control valve; OU-discharge control valve; n is the corresponding nth integrated reactor. DETAILED DESCRIPTION

[0026] The present application will be described in detail below in conjunction with the drawings and examples.

[0027] As Figures 1 to 3 shown, the core of the integrated reactor and system for low-temperature wet-heat coalification of organic wet slurry of the present application is the parallel arrangement of multiple integrated reactor systems.

[0028] In a preferred embodiment, the total length of the integrated reactor 2 is about 10.5 m, the outer diameter (D) is 600 mm, and the inner tube wall diameter (d) is 300 mm: - The heat exchange section 209 is designed to be about 6.5m in length, with a length-diameter ratio (6.5m / 0.6m) of 10.83:1, falling within the range of 6:1 to 12:1; - The heating section 210 is designed to be about 2m in length, with a length-diameter ratio (2m / 0.6m) of 3.33:1, falling within the range of 3:1 to 6:1; - The length ratio of the heat exchange section to the heating section is 6.5:2 = 3:1, which falls within the range of 2:1 to 4:1; - According to the relationship in claim 3, the length of the reaction section needs to satisfy L > K * (0.6)^2 / 0.3 = K *1.2. The coefficient K needs to be determined according to the material characteristics. The length (L) of the reaction section 211 is designed to be 2m, which is much larger than the calculated value, ensuring sufficient reaction residence time; - The inner tube wall 205 extends into the reaction section 211 by about 0.8m, accounting for about 40% of the total length of the reaction section, falling within the range of 1 / 3 to 1 / 2; - The heating layer 203 is wrapped around the outer wall of both the heating section 210 and the reaction section 211, providing heat energy for them.

[0029] When the system starts, the central control unit 6 starts a corresponding number of integrated reactor systems (for example, 4, each with a rated capacity of 3 tons / hour) according to the required processing capacity (for example, 12 tons per hour). The pretreated kitchen waste wet slurry is distributed to the feed inlet 213 of the 4 reactors through the conveying system 1 (which can be a screw pump / plunger pump).

[0030] The material first enters the inner tube layer 202 (second flow channel). In the heat exchange section 209, the cold material is counter-currently exchanged with the hot material from the first flow channel (outer tube layer 201), and the temperature is initially raised. In the heating section 210, the external heater 3 precisely heats the material through the heating layer 203 (jacket), so that it reaches the set reaction temperature (for example, 220℃). Subsequently, the material enters the reaction section 211 and undergoes sufficient coalification reaction under the condition of heat and pressure preservation.

[0031] The reacted hot material turns back at the bottom of the reaction section 211 and enters the outer tube layer 201 (first flow channel), flowing in the opposite direction. In the heating section 210 and the heat exchange section 209, the hot material transfers heat to the cold material in the inner tube layer 202, and then is discharged through the outlet control valve OU after being cooled down.

[0032] During the process, the control unit C of each reactor system works independently: the liquid level sensor L monitors the liquid level in the reactor, controls the coordinated opening and closing of the inlet and outlet valves IN, OUT, and keeps the liquid level stable; the temperature sensor T monitors the temperature and feeds back to adjust the steam flow of the heater 3; the pressure sensor P monitors the pressure to ensure safety. At the same time, the magnetic stirring motor 208 drives the double-layer stirring wall scraper 204 to rotate slowly at a speed of 2-4 RPM, continuously scraping all the key heat transfer walls. The ultrasonic transducers 212 arranged at various places operate in intermittent mode (such as 2 minutes of work and 5 minutes of stop), emitting ultrasonic waves to prevent particle deposition and scale adhesion.

[0033] The central control unit 6 monitors the operating state of all reactors. The algorithm built-in the system dynamically calculates the heat transfer coefficient (K value) of each reactor based on the real-time monitored temperature and flow data. If the central control unit 6 monitors that the calculated heat transfer coefficient K value of a reactor continues to decline and is lower than the set alarm threshold, it will determine that the reactor may have a scaling trend. Then, it will issue a coordination instruction to the control unit C of the reactor, instructing it to increase the speed of the double-layer stirring wall scraper 204 and / or adjust the working mode of the ultrasonic transducer 212 to perform a cleaning cycle. Until the K value is monitored to rise to the normal range, it will instruct it to return to the normal operation mode. Thus, precise and efficient intelligent management is achieved.

[0034] All the materials discharged from the reactors are collected and then enter the cooler 4 for further cooling to an appropriate temperature, and finally enter the solid-liquid separator 5 (such as a centrifuge or plate-and-frame filter press) to be separated into solid coal products and liquid wastewater, which are respectively used for resource utilization.

[0035] The above examples are only used to illustrate the technical solutions of the present application and not to limit it. Those skilled in the art should understand that the present application can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. An integrated reactor and system for organic wet slurry low temperature hydrothermal coalification, characterized in that, The system comprises a conveying system, a plurality of integrated reactor systems arranged in parallel, a cooler, a solid-liquid separator, and a central control unit; The central control unit is communicatively connected to and centrally controls the operation of the conveying system, the cooler, the solid-liquid separator, and each integrated reactor system; The integrated reactor system comprises an integrated reactor, a heater, a liquid level sensor, a pressure sensor, a temperature sensor, a reactor control unit, a feed control valve, and a discharge control valve; the reactor control unit receives signals from the liquid level sensor, the pressure sensor, and the temperature sensor, and independently controls the operation of the heater, the feed control valve, and the discharge control valve; The integrated reactor comprises an outer tube layer and an inner tube layer arranged coaxially, and a heating layer wrapped around the outer wall of part of the outer tube layer; an annular gap between the outer tube layer and the inner tube layer forms a first flow channel, and a cavity inside the inner tube layer forms a second flow channel; the integrated reactor is sequentially divided into a heat exchange section, a heating section, and a reaction section along the material flow direction; the inner tube wall extends from the heat exchange section to the heating section and extends into the interior of the reaction section; The integrated reactor is further provided with a double-layer stirring and wall scraping device, a magnetic drive stirring motor, and a plurality of ultrasonic transducers; The double-layer stirring and wall scraping device comprises a first wall scraping assembly arranged on the inner and outer sides of the inner tube wall, and a second wall scraping assembly arranged on the inner wall of the heating section and the reaction section; The ultrasonic transducers are distributed on the wall surface of the integrated reactor at the areas of the slag discharge port, the heat exchange section near the heating section, the middle of the heating section, and the middle of the reaction section.

2. The organic wet slurry low temperature hydrothermal coalification integrated reactor and system according to claim 1, wherein, The length-diameter ratio of the heat exchange section is 6:1 to 12:1, and the length-diameter ratio of the heating section is 3:1 to 6:1; the length of the inner tube wall extending into the reaction section is 1 / 3 to 1 / 2 of the total length of the reaction section.

3. The organic wet slurry low temperature hydrothermal coalification integrated reactor and system according to claim 2, wherein, The length ratio of the heat exchange section to the heating section is 2:1 to 4:1; the length of the reaction section satisfies the following relationship: L > K × D² / d, where L is the length of the reaction section, D is the diameter of the outer tube wall, d is the diameter of the inner tube wall, and K is a coefficient determined by the reaction kinetics characteristics of the material; the heating layer simultaneously wraps the corresponding outer tube walls of the heating section and the reaction section.

4. The organic wet slurry low temperature hydrothermal coalification integrated reactor and system of claim 1, wherein, The reactor control unit is configured to: receive signals from the liquid level sensor, control the feed control valve to reduce the opening or close when the liquid level is higher than a first set value, and control the discharge control valve to increase the opening or open at the same time; when the liquid level is lower than a second set value, perform the opposite control; receive signals from the temperature sensor, control the output power of the heater or the flow rate of the heating medium to maintain the set temperature; receive signals from the pressure sensor, perform shutdown or pressure relief protection operation when the pressure exceeds the safe range, and upload the signals to the central control unit.

5. The organic wet slurry low temperature hydrothermal coalification integrated reactor and system of claim 4, wherein, The central control unit is configured to: calculate and decide the start-stop number of each integrated reactor system according to the total processing demand of the system and the real-time processing capacity and heat transfer performance of each integrated reactor system; and coordinate each reactor control unit to monitor and adjust the rotating speed, operation time, and interval period of the double-layer stirring and wall scraping device, and the working frequency and start-stop period of the ultrasonic transducers.

6. An organic wet slurry low temperature hydrothermal coal treatment process using the system of any one of claims 1 to 5, characterized in that, The method comprises the following steps: (1) The central control unit controls the conveying system to distribute the pretreated organic wet slurry to one or more integrated reactor systems in parallel according to the set total processing capacity; (2) The organic wet slurry first enters the second flow channel of the integrated reactor, and is preheated by heat exchange with the hot material in the first flow channel in the heat exchange section; then enters the heating section and is indirectly heated to the reaction temperature by the heating layer; and then enters the reaction section for heat preservation and pressure maintaining reaction; The reacted material returns to the first flow channel, sequentially flows through the reaction section, the heating section, and the heat exchange section, is cooled by heat exchange with the cold material in the second flow channel, and is discharged through the discharge control valve; During the whole process, the reactor control unit adjusts the working states of the feed valve, the discharge valve, and the heater in real time according to the liquid level, temperature, and pressure signals, and controls the intermittent or continuous operation of the double-layer stirring and wall scraping device and the ultrasonic vibrator to prevent fouling and coking and maintain the heat transfer efficiency; (3) The materials discharged from the integrated reactor systems are collected and then enter the cooler for final cooling, and then enter the solid-liquid separator to be separated into solid coal products and liquid waste water, which are respectively subjected to subsequent treatment.

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