Design method of stepped functional thermal desorption treatment device and thermal desorption treatment device

Abstract

The invention discloses a design method of a stepped functional thermal desorption treatment device and the thermal desorption treatment device. The method comprises the following steps: carrying out a thermogravimetric experiment on a material, and determining each temperature range stage of a thermal desorption treatment device; determining the heat demand of each temperature range stage; determining the heat transfer amount of each temperature range stage according to the heat demand amount; calculating the heat transfer area of each temperature range according to the heat transfer amount and the heat transfer temperature difference of each temperature range stage; and determining the structure and operation parameters of the thermal desorption treatment device according to the heat transfer area, the relationship between the heat transfer area and each structure and operation parameter, the relationship between the treatment capacity of each temperature range stage and the structure and operation parameter, the preset design parameters and the parameters of the in-furnace conveying component of the thermal desorption treatment device. The temperature range stages are divided on the basis of thermal gravimetry and thermal desorption experimental data of the oil-containing solid waste, the design of the thermal desorption treatment device is closely related to material properties, the practicability is high, and the requirement for division of the temperature range stages of thermal desorption devices of different types of oil-containing solid waste can be met.

Description

Technical Field

[0001] The invention relates to the technical field of oil-containing solid waste treatment in the petrochemical industry, and in particular to a design method for a stepped function thermal desorption treatment device and a thermal desorption treatment device. Background Art

[0002] During the oil and gas exploration and development process, a large amount of oily sludge, oil-based drill cuttings and oil-contaminated soil (hereinafter referred to as oily solid waste) will be generated. The oily solid waste contains petroleum hydrocarbons and has been listed in the category of national hazardous waste. If it is not treated safely and effectively, it will inevitably cause pollution to the environment.

[0003] Thermal desorption technology has the advantages of thorough treatment, strong material adaptability, high resource recycling rate, and less secondary pollution, and has become a hot technology for the treatment of oil-based drilling cuttings and petroleum-contaminated soil. At present, the thermal desorption treatment device for oil-containing solid waste adopts the isothermal heating method. The heating temperature and energy density in the thermal desorption process are the same, resulting in high energy consumption in the thermal desorption process, which restricts the widespread application of thermal desorption treatment technology.

[0004] At present, thermal desorption treatment devices are mostly designed using empirical methods, that is, using empirical formulas or design experience of designers to guide the structural design of thermal desorption treatment devices, which lacks theoretical basis. Summary of the invention

[0005] In view of the above problems, the present invention is proposed to provide a design method of a stepped functional thermal desorption treatment device and a thermal desorption treatment device that overcomes the above problems or at least partially solves the above problems.

[0006] In a first aspect, an embodiment of the present invention provides a design method for a stepped function thermal desorption processing device, characterized in that it includes:

[0007] Conduct thermogravimetric experiments on the materials to be treated by the thermal desorption device to be designed, and determine the various temperature stages required by the thermal desorption device;

[0008] Determining the heat requirement of each temperature stage of the thermal desorption device;

[0009] Determine the heat transfer amount of the thermal desorption treatment device at each temperature stage according to the heat demand of the thermal desorption treatment device at each temperature stage;

[0010] Calculating the heat transfer area of ​​each temperature range according to the heat transfer amount and the heat transfer temperature difference of each temperature range of the thermal desorption device;

[0011] The structure and operating parameters of the thermal desorption treatment device are determined based on the heat transfer area of ​​each temperature range, the relationship between the heat transfer area and the structures and operating parameters of the thermal desorption treatment device, the relationship between the processing volume of each temperature stage and the structure and operating parameters of the thermal desorption treatment device, as well as the preset design parameters of the thermal desorption treatment device and the parameters of the conveying components in the furnace of the thermal desorption treatment device.

[0012] In one embodiment, determining the heat requirement of each temperature range of the thermal desorption device to be designed includes:

[0013] The heat requirement of each temperature stage of the thermal desorption device is calculated according to the following formula:

[0014] Q xi =∑Q Li +∑Q Qi ;

[0015] Among them, Q xi Q is the heat required for thermal desorption process in temperature stage i; Li Q is the heat required for the heating process of the non-volatile material in the i temperature stage; Qi The heat required for the phase change process of the volatile material in the i temperature stage;

[0016] The Q Li and Q Qi Obtained from the results of the thermogravimetric experiment.

[0017] In one embodiment, the heat transfer amount of the thermal desorption treatment device at each temperature stage is determined according to the heat requirement of the thermal desorption treatment device at each temperature stage, including:

[0018] According to the thermal desorption steady state, the required heat in the same temperature stage is equal to the corresponding heat transfer Q ci =Q xi , determine the heat transfer amount at each temperature stage;

[0019] In the above formula: Q ci Q is the heat transfer of the thermal desorption treatment device at the temperature stage i; xi The heat required for the thermal desorption process in the i temperature stage.

[0020] In one embodiment, the heat transfer area of ​​each temperature range is calculated according to the heat transfer amount and the heat transfer temperature difference of each temperature range of the thermal desorption device, including:

[0021] Calculate the heat transfer temperature difference at each temperature stage;

[0022] The heat transfer area at each temperature stage is calculated according to the following formula:

[0023] H i =Q xi / (Ki Δt i );

[0024] K i is the heat transfer coefficient of the thermal desorption treatment device at the temperature stage i; H i is the heat transfer area of ​​the thermal desorption treatment device at the temperature stage i; Δt i is the heat transfer temperature difference of the thermal desorption treatment device in the i temperature stage.

[0025] In one embodiment, the heat transfer temperature difference in each temperature range is calculated according to the following formula:

[0026] Δt i =(t″ i -t′ i ) / ln[(t bi -t′ i )-(t bi -t″ i )];

[0027] In the above formula: t i 'With t i ” are the inlet temperature and outlet temperature of the material in the i temperature stage, which are determined by the preset design parameters; t bi is the heating temperature of the thermal desorption treatment device in the i temperature stage, which is determined by the thermogravimetric test results.

[0028] In one embodiment, the thermal desorption treatment device is a fixed spiral-propelled thermal desorption treatment device;

[0029] The structure and operating parameters of the thermal desorption treatment device are determined according to the heat transfer area of ​​each temperature range, the relationship between the heat transfer area and each structure and operating parameter of the thermal desorption treatment device, the relationship between the processing volume of each temperature range stage and the structure and operating parameters of the thermal desorption treatment device, and the preset design parameters of the thermal desorption treatment device and the parameters of the conveying components in the furnace of the thermal desorption treatment device, including:

[0030] A combination of multiple thermal desorption treatment device structures and operating parameters that meet the processing time of each temperature stage and the processing volume of each temperature stage is calculated, and the combination of thermal desorption treatment device structures and operating parameters includes: the inner diameter of the furnace body of the thermal desorption treatment device, the furnace body length of each temperature range, the pitch of the conveying screw in the furnace body, and the rotation speed of the conveying screw;

[0031] The combination of structure and operating parameters with the lowest material consumption and / or the lowest manufacturing cost in the trial calculation results is selected as the final structure and operating parameters of the thermal desorption treatment device.

[0032] In one embodiment, a combination of multiple thermal desorption processing device structures and operating parameters that meet the processing time of each temperature stage and the processing volume of each temperature stage is calculated, including:

[0033] The combinations of thermal desorption device structures and operating parameters that satisfy the following formula are calculated:

[0034] τ i =[H i / (πD)] / (Sn); where: τ i is the treatment time of the i-th temperature stage; D is the inner diameter of the furnace body of the thermal desorption treatment device; S is the pitch of the conveying screw in the furnace body; n is the rotation speed of the conveying screw;

[0035] m i =15πρ i φ i D 2 S N z =m(1-∑C i );where: m i is the processing capacity of the thermal desorption treatment device at the temperature stage i; ρ i is the density of the material at the temperature stage i; φ i is the filling rate of the conveying screw at the i-th temperature stage; Cz is the correction coefficient of the conveying screw; the single screw takes a value of 1.0, and the double screw takes a value of 1.5; m is the processing capacity of the thermal desorption treatment device, which is determined by the preset design parameters; C i is the thermal weight loss rate in temperature stage i, which is determined by the thermogravimetric test results.

[0036] In one embodiment, the thermal desorption treatment device is a rotary kiln thermal desorption treatment device;

[0037] The structure and operating parameters of the thermal desorption treatment device are determined according to the heat transfer area of ​​each temperature range, the relationship between the heat transfer area and each structure and operating parameter of the thermal desorption treatment device, the relationship between the processing volume of each temperature range stage and the structure and operating parameters of the thermal desorption treatment device, and the preset design parameters of the thermal desorption treatment device and the parameters of the conveying components in the furnace of the thermal desorption treatment device, including:

[0038] A combination of multiple thermal desorption treatment device structures and operating parameters that meet the processing time of each temperature stage and the processing volume of each temperature stage is calculated, and the combination of thermal desorption treatment device structures and operating parameters includes: the horizontal inclination angle of the cylinder of the thermal desorption treatment device, the inner diameter of the rotating cylinder, and the rotation speed of the rotating cylinder;

[0039] The combination of structure and operating parameters with the lowest material consumption and / or the lowest manufacturing cost in the trial calculation results is selected as the final structure and operating parameters of the thermal desorption treatment device.

[0040] In one embodiment, a combination of multiple thermal desorption processing device structures and operating parameters that meet the processing time of each temperature stage and the processing volume of each temperature stage is calculated, including:

[0041] The combinations of thermal desorption device structures and operating parameters that satisfy the following formula are calculated:

[0042] When there is no copy board inside the cylinder, the processing time of each temperature stage: τ i =[H i / (πD)](θ+24) / (324Dnsinα); where: θ is the natural inclination of the material, which is determined by the design parameters; α is the horizontal inclination of the cylinder, which is no more than 6°;

[0043] When there is a copy board inside the cylinder, the processing time of each temperature stage: τ i =mk(H i / D) / (Dnsinα); where: m and k are coefficients related to the form of the copy board, the flow direction of the material, the flow direction of the heat carrier, the material density, etc., and they are taken as constants;

[0044] Processing volume at each temperature stage: m i =[φ i ρ i (H i / π)D] / (2.12×10 -2 Jτ i )=m(1-C i );Wherein: J is the structural influence coefficient, which takes the value of 1.0 when there is no baffle plate or copying plate accessory in the cylinder, takes the value of 1.1-1.2 when there is a baffle plate or copying plate but no other accessories in the cylinder, and takes the value of 1.30-1.45 when there are other accessories in addition to the baffle plate or copying plate in the cylinder.

[0045] In one embodiment, during the trial calculation of multiple combinations of thermal desorption processing device structures and operating parameters, the following conditions must also be met:

[0046] The total duration of the thermal desorption treatment is calculated based on the treatment time of each temperature stage, which meets the requirements of the design parameters.

[0047] In a second aspect, an embodiment of the present invention provides a thermal desorption treatment device, the structure and operation parameters of the thermal desorption treatment device are obtained by the design method of the stepped function thermal desorption treatment device as described above.

[0048] In one embodiment, the thermal desorption treatment device is a fixed spiral-propelled thermal desorption treatment device, or a rotary kiln thermal desorption treatment device.

[0049] The beneficial effects of the above technical solution provided by the embodiment of the present invention include at least:

[0050] The design method of the stepped function thermal desorption treatment device and the thermal desorption treatment device provided by the embodiment of the present invention use the data of the thermogravimetric experiment to divide each temperature range stage, and then calculate the heat transfer area of ​​each temperature range according to the heat transfer amount of the thermal desorption treatment device and the heat transfer temperature difference of each temperature range stage of the thermal desorption treatment device; according to the relationship between the heat transfer area and each structure and operation parameter of the thermal desorption treatment device, and the relationship between the processing amount of each temperature range and the structure and operation parameter of the thermal desorption treatment device, as well as the preset design parameters of the thermal desorption treatment device and the parameters of the conveying components in the furnace of the thermal desorption treatment device, the structure and operation parameters of the thermal desorption treatment device are determined by optimization. The above-mentioned design method provided by the embodiment of the present invention divides each temperature range stage based on the thermogravimetric and thermal desorption experimental data of the oil-containing solid waste. The design of the thermal desorption treatment device is closely related to the material properties, has strong practicality, can meet the division of temperature range stages of different types of oil-containing solid waste and thermal desorption devices, is applicable to multi-stage thermal desorption treatment devices and one-stage thermal desorption treatment devices, the material can be heated indirectly or directly, the heat source can be electric energy, combustion heat energy and heat energy of heat carrier, and has a wide range of applications. Moreover, the stepped temperature control heat transfer model is based on the basic heat transfer mode and is determined in combination with the actual situation of the thermal desorption treatment device for oil-containing solid waste. The heat transfer process is simple to calculate and the heat transfer area is accurately calculated. In addition, when selecting the structure and operating parameters of the thermal desorption treatment device, it is based on the design parameters of the thermal desorption treatment device and is determined in combination with the design calculation standards of the conveying components, so that the structure and operating parameters of the thermal desorption treatment device are accurately calculated.

[0051] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0052] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0054] Figure 1 A flow chart of a design method for a stepped function thermal desorption treatment device provided by an embodiment of the present invention;

[0055] Figure 2 A schematic diagram of a thermogravimetric curve provided by an embodiment of the present invention;

[0056] Figure 3A schematic diagram of the structure of a multi-stage fixed spiral propulsion thermal desorption treatment device provided in an embodiment of the present invention;

[0057] Figure 4 A schematic structural diagram of a single-stage fixed spiral propulsion thermal desorption treatment device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0058] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0059] The embodiment of the present invention provides a design method for a step-function thermal desorption treatment device, referring to Figure 1 As shown, the following steps are included:

[0060] S11. Conduct a thermogravimetric experiment on the material to be treated by the thermal desorption device to be designed, and determine the various temperature stages required by the thermal desorption device;

[0061] During the thermogravimetric experiment, samples of the material to be processed by the thermal desorption device to be designed are selected to carry out a thermal desorption experiment, through which the temperature stage of the thermal desorption treatment device and the thermogravimetric curve can be determined.

[0062] Reference Figure 2 As shown, the thermogravimetric curve includes DTA curve, TGA curve and DrTGA curve, wherein the TGA curve indicates the mass percentage of the material changing with temperature, DTA indicates the mass loss of the material for every 1°C change in temperature, that is, the rate of change of mass with temperature, and DrTGA indicates the rate of change of TGA with time.

[0063] S12, determining the heat requirement of each temperature stage of the thermal desorption device;

[0064] S13, determining the heat transfer amount of the thermal desorption treatment device at each temperature stage according to the heat requirement of the thermal desorption treatment device at each temperature stage;

[0065] S14, calculating the heat transfer area of ​​each temperature range according to the heat transfer amount and the heat transfer temperature difference of each temperature range of the thermal desorption device;

[0066] S15. Determine the structure and operating parameters of the thermal desorption treatment device according to the heat transfer area of ​​each temperature range, the relationship between the heat transfer area and the structures and operating parameters of the thermal desorption treatment device, the relationship between the processing volume of each temperature stage and the structure and operating parameters of the thermal desorption treatment device, as well as the preset design parameters of the thermal desorption treatment device and the parameters of the conveying components in the furnace of the thermal desorption treatment device.

[0067] The above-mentioned design method provided by the embodiment of the present invention is based on the thermogravimetric experiment and thermogravimetric experiment data of the material, and divides the thermal desorption treatment process according to temperature stages. Each temperature stage is heated according to different heating temperatures and heating powers to achieve the purpose of step-by-step energy supply.

[0068] The above-mentioned design method provided in the embodiment of the present invention can be applied to the design of a multi-stage thermal desorption treatment device and a one-stage thermal desorption treatment device. The material is thermally desorbed in the thermal desorption treatment device by indirect or direct heating. The heat source can be electric energy, heat energy from fuel combustion, and heat carrier (such as flue gas, etc.). The material enters the thermal desorption treatment device from the low-temperature section, and the thermal desorption residue is discharged from the high-temperature section. A stepped energy supply method is adopted in each temperature stage (without having to use the same heating temperature, power and heating time in each stage), thereby reducing the overall energy consumption of the thermal desorption treatment device.

[0069] The design method of the thermal desorption treatment device provided in the embodiment of the present invention is designed based on the step-by-step energy supply system, that is, the heat supply of each temperature stage is determined according to the heat requirement of the material at each temperature stage. The specific process is as follows:

[0070] (1) Determine the heat requirement at each temperature stage: Q xi =∑Q Li +∑Q Qi ; Where: Q xi Q is the heat required for thermal desorption process in temperature stage i; Li Q is the heat required for the heating process of the non-volatile material in the i temperature stage; Qi The heat required for the phase change process of the volatile part of the material in the i temperature stage.

[0071] (2) Determine the heating amount at each temperature stage: Q i =Q xi / η i ; Where: Q i is the heat supply of the thermal desorption treatment device at the temperature stage i; η i is the thermal efficiency of the thermal desorption treatment device in the i temperature stage.

[0072] (3) Total heat supply of thermal desorption treatment device: Q = ∑Q i ; Where: Q is the total heat supply of the thermal desorption treatment device.

[0073] The design method of the stepped functional thermal desorption treatment device in the embodiment of the present invention completes the heat transfer design of the thermal desorption treatment device based on the relationship between the heat requirement of the material and the heat transfer amount of the thermal desorption treatment device, that is: when the heat requirement of the material and the heat transfer amount of the device are equal in each temperature stage, the heat transferred by the thermal desorption treatment device is all used in the thermal desorption process of the material, and the energy utilization is in an optimal state; if the heat requirement of the material is greater than the heat transfer amount of the device, the thermal desorption treatment effect of the material will not meet the standard; if the heat requirement of the material is less than the heat transfer amount of the device, the excess heat will be dissipated into the environment or cause the thermal desorption treatment device to heat up, resulting in energy waste.

[0074] Based on this, in the above step S13, the heat transfer amount of the thermal desorption treatment device at each temperature stage is determined according to the heat requirement of the thermal desorption treatment device at each temperature stage, which can be specifically achieved by the following method:

[0075] According to the thermal desorption steady state, the required heat in the same temperature stage is equal to the corresponding heat transfer Q ci =Q xi , determine the heat transfer amount in each temperature stage (i.e., equal to the heat requirement in the same temperature stage);

[0076] In the above formula: Q ci Q is the heat transfer of the thermal desorption treatment device at the temperature stage i; xi The heat required for the thermal desorption process in the i temperature stage.

[0077] Furthermore, in the above step S14, the heat transfer area of ​​each temperature range is calculated according to the heat transfer amount and the heat transfer temperature difference of each temperature range of the thermal desorption device, which is specifically achieved in the following manner:

[0078] 1. Calculate the heat transfer temperature difference at each temperature stage;

[0079] For example, the heat transfer temperature difference in each temperature range stage can be calculated according to the following formula:

[0080] Δt i =(t″ i -t′ i ) / ln[(t bi -t′ i )-(t bi -t″ i )];

[0081] In the above formula: t i 'With t i ” are the inlet temperature and outlet temperature of the material in the i temperature stage, which are determined by the preset design parameters; t bi is the heating temperature of the thermal desorption treatment device in the i temperature stage, which is determined by the thermogravimetric test results.

[0082] 2. Calculate the heat transfer area at each temperature stage according to the following formula:

[0083] H i =Q xi / (K i Δt i );

[0084] K i is the heat transfer coefficient of the thermal desorption treatment device at the temperature stage i; H i is the heat transfer area of ​​the thermal desorption treatment device at the temperature stage i; Δt i is the heat transfer temperature difference of the thermal desorption treatment device in the i temperature stage.

[0085] Based on the heat transfer area of ​​each temperature stage mentioned above, the sum of the heat transfer areas of each temperature stage is calculated to obtain the total heat transfer area of ​​the thermal desorption treatment device: H = ∑H i ; Where: H is the total heat transfer area of ​​the thermal desorption treatment device.

[0086] Furthermore, based on the heat transfer area of ​​the aforementioned temperature ranges, the relationship between the heat transfer area and the structures and operating parameters of the thermal desorption treatment device, as well as the relationship between the processing capacity of each temperature stage and the structure and operating parameters of the thermal desorption treatment device, the design parameters of the thermal desorption treatment device and the parameters of the conveying components in the furnace of the thermal desorption treatment device are preset, the structure and operating parameters of the thermal desorption treatment device are determined.

[0087] Specifically, in the first case, the thermal desorption treatment device is a fixed spiral-propelled thermal desorption treatment device;

[0088] Accordingly, a combination of multiple thermal desorption treatment device structures and operating parameters that meet the processing time of each temperature stage and the processing volume of each temperature stage is calculated, and the combination of thermal desorption treatment device structures and operating parameters includes: the inner diameter of the furnace body of the thermal desorption treatment device, the furnace body length of each temperature range, the pitch of the conveying screw in the furnace body, and the rotation speed of the conveying screw;

[0089] Select the best trial calculation result, for example, select the combination of structure and operating parameters with the lowest material consumption and / or lowest production cost from the trial calculation results (excluding unfeasible combinations of structure and operating parameters), as the final structure and operating parameters of the thermal desorption treatment device.

[0090] Reference Figure 3 As shown, Figure 3It is a structural schematic diagram of a multi-stage (for example, two-stage) fixed spiral propulsion thermal desorption treatment device, in which a conveying spiral is included, and the furnace body is divided into two sections according to the temperature range, and power supply 1 and power supply 2 are respectively provided, as well as a thermal desorption gas outlet for the first temperature range stage and a thermal desorption gas outlet for the second temperature range stage. After the material enters through the material inlet, it is discharged from the residue outlet after being subjected to thermal desorption treatment in two temperature range stages.

[0091] Reference Figure 4 As shown, Figure 4 It is a schematic diagram of the structure of a single-stage fixed spiral propulsion thermal desorption treatment device. Figure 3 Similar, but the difference is that it is a single-temperature thermal desorption process (one heating power supply and one thermal desorption gas outlet).

[0092] In the embodiment of the present invention, refer to Figure 3 As shown, the thermal desorption gas outlet of each temperature stage of the step-energy thermal desorption treatment device is located in the high-temperature section of each temperature stage, that is, close to 1 / 3 of the material outlet of each temperature stage.

[0093] Furthermore, the above-mentioned trial calculation process may, for example, be used to perform trial calculations on a combination of multiple thermal desorption treatment device structures and operating parameters that satisfy the following formula:

[0094] τ i =[H i / (πD)] / (Sn); where: τ i is the treatment time of the i-th temperature stage; D is the inner diameter of the furnace body of the thermal desorption treatment device; S is the pitch of the conveying screw in the furnace body; n is the rotation speed of the conveying screw;

[0095] m i =15πρ i φ i D 2 S N z =m(1-∑C i );where: m i is the processing capacity of the thermal desorption treatment device at the temperature stage i; ρ i is the density of the material at the temperature stage i; φ i is the filling rate of the conveying screw at the i-th temperature stage; Cz is the correction coefficient of the conveying screw; the single screw takes a value of 1.0, and the double screw takes a value of 1.5; m is the processing capacity of the thermal desorption treatment device, which is determined by the preset design parameters; C i is the thermal weight loss rate in temperature stage i, which is determined by the thermogravimetric test results.

[0096] Specifically, in the second case, the thermal desorption treatment device is a rotary kiln type thermal desorption treatment device;

[0097] Accordingly, a combination of multiple thermal desorption treatment device structures and operating parameters that meet the processing time of each temperature stage and the processing volume of each temperature stage is calculated, and the combination of thermal desorption treatment device structures and operating parameters includes: the horizontal inclination angle of the cylinder of the thermal desorption treatment device, the inner diameter of the rotating cylinder, and the rotation speed of the rotating cylinder;

[0098] Select the best trial calculation result, for example, select the combination of structure and operating parameters with the lowest material consumption and / or lowest production cost from the trial calculation results (excluding unfeasible combinations of structure and operating parameters), as the final structure and operating parameters of the thermal desorption treatment device.

[0099] Furthermore, the above trial calculation is performed, for example, for a combination of multiple thermal desorption treatment device structures and operating parameters that satisfy the following formula:

[0100] When there is no copy board inside the cylinder, the processing time of each temperature stage: τ i =[H i / (πD)](θ+24) / (324Dnsinα); where: θ is the natural inclination of the material, which is determined by the design parameters; α is the horizontal inclination of the cylinder, which is no more than 6°;

[0101] For example, α can generally be taken as 0° to 3°, such as 1.5° to 3°, and generally does not exceed 6°.

[0102] When there is a copy board inside the cylinder, the processing time of each temperature stage: τ i =mk(H i / D) / (Dnsinα); where: m and k are coefficients related to the form of the copy board, the flow direction of the material, the flow direction of the heat carrier, the material density, etc., and they are taken as constants;

[0103] Processing volume at each temperature stage: m i =[φ i ρ i (H i / π)D] / (2.12×10 -2 Jτ i )=m(1-C i );Wherein: J is the structural influence coefficient, which takes the value of 1.0 when there is no baffle plate or copying plate accessory in the cylinder, takes the value of 1.1-1.2 when there is a baffle plate or copying plate but no other accessories in the cylinder, and takes the value of 1.30-1.45 when there are other accessories in addition to the baffle plate or copying plate in the cylinder.

[0104] Whether it is a fixed spiral propulsion thermal desorption treatment device or a rotary kiln thermal desorption treatment device, in the process of trial calculation of the combination of multiple thermal desorption treatment device structures and operating parameters, it is also necessary to meet the following requirements:

[0105] The total duration of the thermal desorption treatment is calculated based on the treatment time of each temperature stage, which meets the requirements of the design parameters.

[0106] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0107] Taking a certain oil field petroleum contaminated soil as an example, a thermal desorption treatment device with a designed treatment capacity of 1 t / h is used. This embodiment adopts a fixed spiral propulsion thermal desorption treatment device, and the structural design methods of the multi-stage and one-stage structural forms are respectively used as examples to illustrate.

[0108] 1.Material properties and design parameters:

[0109] According to the indoor experimental results, the petroleum contaminated soil sample has a moisture content of 10%, an oil content of 10%, and a density of 1.19 kg / cm 3 According to the temperature range, it can be divided into two stages: the first stage is room temperature ~ 150℃, which is mainly for the volatilization of water; the second stage is 150℃ ~ 350℃, which is mainly for the volatilization of oil substances.

[0110] The design parameters of this embodiment are: processing capacity: 1t / h; thermal desorption treatment temperature: 350°C; ambient temperature: 20°C; thermal desorption treatment time: 30min; material properties: water content 10%, oil content 10%, density: 1.19kg / cm 3 ; The properties of the residue after treatment: 0% water content, 1% oil content; The thermal desorption treatment device adopts a fixed spiral propulsion thermal desorption treatment device ( Figure 2 and Figure 3 ), the heating method is electromagnetic heating.

[0111] 2. One-stage thermal desorption treatment device (its structure can refer to Figure 4 ).

[0112] (1) Determination of heat supply

[0113] Since the one-stage thermal desorption treatment device has only one thermal desorption gas outlet, the moisture and oil substances in the thermal desorption gas will be heated to a temperature close to that of the residue. According to the results of thermogravimetric experiments, the heat required to heat the material to 350°C is 628.852 kJ / kg, so the heat required to process 1 t / h of material is:

[0114]

[0115] The thermal efficiency of the electromagnetic heating thermal desorption treatment device is 95%, and the heat supply of the thermal desorption treatment device is:

[0116] Q=Q x / η=183.875kW.

[0117] (2) Determination of heat transfer area and heat transfer temperature difference

[0118] The heating temperature of the thermal desorption treatment device is 550°C, and the heat transfer temperature difference of the thermal desorption treatment device is: Δt=(t″-t′) / ln[(t b -t′)-(t b -t″)]=338.614°C;

[0119] The heat transfer coefficient of the thermal desorption treatment device is 19.766W / (m 2 ·℃), the heat transfer area of ​​the thermal desorption treatment device is: H = Q x / (KΔt)=26.098m 2 ;

[0120] (3) Determination of structure and operating parameters

[0121] Through calculation, when the inner diameter of the thermal desorption treatment device is 450mm, the pitch of the spiral conveying screw is 250mm, the conveying screw speed is 2.4r / min, the conveying screw filling rate is 0.15, and the spiral structure is a single spiral, the processing capacity and processing time of the thermal desorption treatment device meet the design parameter requirements, and the processing capacity and processing time are respectively:

[0122] Thermal desorption treatment device processing capacity: m = 15πρφD 2 S N z =1022.011kg / h;

[0123] Thermal desorption treatment device treatment time: τ = [H / (πD)] / (Sn) = 30.767 min;

[0124] Total length of thermal desorption treatment device: L = H / (πD) = 18.460m;

[0125] 3. Multi-stage thermal desorption treatment device (its structure can refer to Figure 3 )

[0126] According to the indoor experimental results, the multi-stage thermal desorption treatment device should be divided into two temperature stages: the first temperature stage is room temperature to 150°C, and the second temperature stage is 150°C to 350°C.

[0127] (1) Determination of heat supply

[0128] According to the results of thermogravimetric experiments, the heat required to heat the material from room temperature to 150°C is 388.688 kJ / kg, and the heat required to heat the material from 150°C to 350°C is 200.239 kJ / kg. The heat required to process 1 t / h of material is:

[0129] Heat required in the first temperature stage:

[0130] Heat required in the second temperature stage:

[0131] The thermal efficiency of the electromagnetic heating thermal desorption treatment device is 95%, and the heat supply of the thermal desorption treatment device is:

[0132] Heating supply in the first temperature stage: Q1 = Q x1 / η=113.652kW;

[0133] Heating supply in the second temperature stage: Q2 = Q x2 / η=58.550kW;

[0134] The total heat required for the multi-stage thermal desorption treatment device is: Q x3 =Q x1 +Q x2 =163.591kW;

[0135] The total heat supply of the multi-stage thermal desorption treatment device is: Q3 = Q1 + Q2 = 172.201 kW.

[0136] (2) Determination of heat transfer area and heat transfer temperature difference

[0137] In the first temperature stage, the heating temperature of the thermal desorption treatment device is 450°C, and the heat transfer temperature difference of the thermal desorption treatment device is: Δt1 = (tt′ i ) / ln[(t b1 -t′ i )-(t b1 -t)] = 361.108 ° C;

[0138] The heat transfer coefficient of the thermal desorption treatment device in the first temperature stage is 24.865W / (m 2 ·℃), the heat transfer area of ​​the thermal desorption treatment device is: H1=Q x1 / (K1Δt1)=12.025m 2 ;

[0139] In the second temperature stage, the heating temperature of the thermal desorption treatment device is 550°C, and the heat transfer temperature difference of the thermal desorption treatment device is: Δt2=(t″-t) / ln[(t b2 -t)-(t b2 -t″)]=288.539°C;

[0140] The heat transfer coefficient of the thermal desorption treatment device in the second temperature process is 21.232W / (m 2 ·℃), the heat transfer area of ​​the thermal desorption treatment device is: H2=Q x2 / (K2Δt2)=9.079m 2 ;

[0141] The total heat transfer area of ​​the multi-stage thermal desorption treatment device is: H3 = H1 + H2 = 21.104m 2 .

[0142] (3) Determination of structure and operating parameters

[0143] Through calculation, when the inner diameter of the multi-stage thermal desorption treatment device is 450mm, the pitch of the spiral conveying screw is 250mm, the conveying screw speed is 1.9r / min, the conveying screw filling rate in the first temperature stage is 0.19, the conveying screw filling rate in the second temperature stage is 0.17, and the spiral structure is a single spiral, the processing capacity and processing time of the multi-stage thermal desorption treatment device meet the design parameter requirements, and the processing capacity and processing time are:

[0144] The first stage of thermal desorption treatment equipment processing capacity: m i =15πρφ1D 2 S N z =1024.850kg / h;

[0145] The first temperature stage thermal desorption treatment device treatment time: τ1 = [H1 / (πD)] / (Sn) = 17.907min;

[0146] The length of the thermal desorption treatment device in the first temperature process stage: L1 = H1 / (πD) = 8.506m;

[0147] The second temperature stage thermal desorption treatment device processing capacity: m2 = 15πρφ2D 2 S N z =916.971kg / h;

[0148] The second temperature stage thermal desorption treatment device treatment time: τ2 = [H2 / (πD)] / (Sn) = 13.521min;

[0149] The length of the thermal desorption treatment device in the second temperature process stage: L2 = H2 / (πD) = 6.422m;

[0150] Total treatment time of the multi-stage thermal desorption treatment device: τ3 = τ1 + τ2 = 31.427 min;

[0151] The total length of the multi-stage thermal desorption treatment device is L3 = L1 + L2 = 14.928 m.

[0152] In this embodiment, the multi-stage thermal desorption treatment device adopts a stepped energy supply method. The heating temperature in the first temperature stage is 450°C, and the heating temperature in the second temperature stage is 550°C. The total heat supply is 172.201kW and the total length is 14.928m.

[0153] In this embodiment, the one-stage thermal desorption treatment device has a heating temperature of 550° C., a total heat supply of 183.875 kW, and a total length of 18.460 m.

[0154] In this embodiment, compared with a one-stage thermal desorption treatment device, the multi-stage thermal desorption treatment device using a stepped energy supply method reduces the heat supply by 6.348% and the total length by 19.134%, that is, the energy consumption of the multi-stage thermal desorption treatment device using a stepped energy supply method is reduced by 6.348%, and the manufacturing cost is reduced by 19.134%.

[0155] Based on the same inventive concept, an embodiment of the present invention further provides a thermal desorption treatment device, the structure and operating parameters of the thermal desorption treatment device are obtained by the design method of the stepped function thermal desorption treatment device as described above.

[0156] Furthermore, the thermal desorption treatment device is a fixed spiral-propelled thermal desorption treatment device, or a rotary kiln thermal desorption treatment device.

[0157] Regarding the thermal desorption processing device in the above embodiment, the specific manner in which each module performs the operation has been described in detail in the embodiment of the method, and will not be elaborated here.

[0158] The design method of the cascade energy supply thermal desorption treatment device provided in the embodiment of the present invention fills the gap in the existing structure and operation parameter design method of the thermal desorption treatment device of oil-containing solid waste, reduces the energy consumption of the thermal desorption treatment device, and has the following advantages and positive effects:

[0159] First, the design method described in the present invention fills the gap in the design method of the structure and operating parameters of the thermal desorption treatment device, makes up for the defect of the existing empirical method lacking a theoretical basis, and improves the technical system of the thermal desorption treatment device.

[0160] Second, the design method described in the present invention divides each temperature stage based on the thermogravimetric and thermal desorption experimental data of oil-containing solid waste. The design of the thermal desorption treatment device is closely related to the material properties and has strong practicality. It can meet the division of temperature stages of thermal desorption devices for different types of oil-containing solid waste.

[0161] Third, the design method described in the present invention is applicable to a multi-stage thermal desorption treatment device and a one-stage thermal desorption treatment device. The material can be heated indirectly or directly. The heat source can be electricity, combustion heat, and heat from a heat carrier. It has a wide range of applications.

[0162] Fourthly, the step-by-step temperature control heat transfer model described in the present invention is based on the basic heat transfer mode and is determined in combination with the actual situation of the thermal desorption treatment device for oil-containing solid waste. The heat transfer process is easy to calculate and the heat transfer area is accurately calculated.

[0163] Fifth, the method for designing the structure and operating parameters of the thermal desorption treatment device of the present invention is based on the design parameters of the thermal desorption treatment device and is determined in combination with the design calculation standard of the conveying component, so that the structure and operating parameters of the thermal desorption treatment device are accurately calculated.

[0164] Sixth, the gas outlet of the thermal desorption treatment device of the present invention is located at 1 / 3 of the material outlet in each temperature stage, which can discharge the thermal desorption gas in time, prevent the thermal desorption gas from cracking, and reduce the energy consumption of the thermal desorption treatment process.

[0165] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A design method for a stepped function thermal desorption treatment device, characterized in that: include: Conduct thermogravimetric experiments on the materials to be treated by the thermal desorption device to be designed, and determine the various temperature stages required by the thermal desorption device; Determining the heat requirement of each temperature stage of the thermal desorption device; Determine the heat transfer amount of the thermal desorption treatment device at each temperature stage according to the heat demand of the thermal desorption treatment device at each temperature stage; Calculating the heat transfer area of ​​each temperature range according to the heat transfer amount and the heat transfer temperature difference of each temperature range of the thermal desorption device; The structure and operating parameters of the thermal desorption treatment device are determined based on the heat transfer area of ​​each temperature range, the relationship between the heat transfer area and the structures and operating parameters of the thermal desorption treatment device, the relationship between the processing capacity of each temperature stage and the structure and operating parameters of the thermal desorption treatment device, as well as the preset design parameters of the thermal desorption treatment device and the parameters of the conveying components in the furnace of the thermal desorption treatment device.

2. The method according to claim 1, characterized in that The step of determining the heat requirement of each temperature range of the thermal desorption device to be designed comprises: The heat requirement of each temperature stage of the thermal desorption device is calculated according to the following formula: Q xi =∑Q Li +∑Q Qi ; Among them, Q xi Q is the heat required for thermal desorption process in temperature stage i; Li Q is the heat required for the heating process of the non-volatile material in the i temperature stage; Qi The heat required for the phase change process of the volatile material in the i temperature stage; The Q Li and Q Qi Obtained from the results of the thermogravimetric experiment.

3. The method according to claim 1, characterized in that According to the heat requirement of the thermal desorption treatment device at each temperature stage, the heat transfer amount of the thermal desorption treatment device at each temperature stage is determined, including: According to the thermal desorption steady state, the required heat in the same temperature stage is equal to the corresponding heat transfer Q ci =Q xi , determine the heat transfer amount at each temperature stage; In the above formula: Q ci Q is the heat transfer of the thermal desorption treatment device at the temperature stage i; xi The heat required for the thermal desorption process in the i temperature stage.

4. The method according to claim 1, characterized in that According to the heat transfer amount and the heat transfer temperature difference of each temperature range of the thermal desorption device, the heat transfer area of ​​each temperature range is calculated, including: Calculate the heat transfer temperature difference at each temperature stage; The heat transfer area at each temperature stage is calculated according to the following formula: H i =Q xi / (K i Δt i ); K i is the heat transfer coefficient of the thermal desorption treatment device at the temperature stage i; H i is the heat transfer area of ​​the thermal desorption treatment device at the temperature stage i; Δt i is the heat transfer temperature difference of the thermal desorption treatment device in the i temperature stage.

5. The method according to claim 1, characterized in that The heat transfer temperature difference in each temperature range is calculated according to the following formula: Δt i =(t″ i -t′ i ) / ln[(t bi -t′ i )-(t bi -t″ i )]; In the above formula: t i 'With t i ” are the inlet temperature and outlet temperature of the material in the i temperature stage, which are determined by the preset design parameters; t bi is the heating temperature of the thermal desorption treatment device in the i temperature stage, which is determined by the thermogravimetric test results.

6. The method according to claim 1, characterized in that The thermal desorption treatment device is a fixed spiral-propelled thermal desorption treatment device; The structure and operating parameters of the thermal desorption treatment device are determined according to the heat transfer area of ​​each temperature range, the relationship between the heat transfer area and each structure and operating parameter of the thermal desorption treatment device, the relationship between the processing volume of each temperature range stage and the structure and operating parameters of the thermal desorption treatment device, and the preset design parameters of the thermal desorption treatment device and the parameters of the conveying components in the furnace of the thermal desorption treatment device, including: A combination of multiple thermal desorption treatment device structures and operating parameters that meet the processing time of each temperature stage and the processing volume of each temperature stage is calculated, and the combination of thermal desorption treatment device structures and operating parameters includes: the inner diameter of the furnace body of the thermal desorption treatment device, the furnace body length of each temperature range, the pitch of the conveying screw in the furnace body, and the rotation speed of the conveying screw; The combination of structure and operating parameters with the lowest material consumption and / or the lowest manufacturing cost in the trial calculation results is selected as the final structure and operating parameters of the thermal desorption treatment device.

7. The method according to claim 6, characterized in that The combination of multiple thermal desorption treatment device structures and operating parameters that meet the processing time of each temperature stage and the processing volume of each temperature stage is calculated, including: The combinations of thermal desorption device structures and operating parameters that satisfy the following formula are calculated: τ i =[H i / (πD)] / (Sn); where: τ i is the treatment time of the i-th temperature stage; D is the inner diameter of the furnace body of the thermal desorption treatment device; S is the pitch of the conveying screw in the furnace body; n is the rotation speed of the conveying screw; m i =15πρ i φ i D 2 S N z =m(1-∑C i );where: m i is the processing capacity of the thermal desorption treatment device at the temperature stage i; ρ i is the density of the material at the temperature stage i; φ i is the filling rate of the conveying screw at the i-th temperature stage; Cz is the correction coefficient of the conveying screw; the single screw takes a value of 1.0, and the double screw takes a value of 1.5; m is the processing capacity of the thermal desorption treatment device, which is determined by the preset design parameters; C i is the thermal weight loss rate in temperature stage i, which is determined by the thermogravimetric test results.

8. The method according to claim 1, characterized in that The thermal desorption treatment device is a rotary kiln type thermal desorption treatment device; The structure and operating parameters of the thermal desorption treatment device are determined according to the heat transfer area of ​​each temperature range, the relationship between the heat transfer area and each structure and operating parameter of the thermal desorption treatment device, the relationship between the processing volume of each temperature range stage and the structure and operating parameters of the thermal desorption treatment device, and the preset design parameters of the thermal desorption treatment device and the parameters of the conveying components in the furnace of the thermal desorption treatment device, including: A combination of multiple thermal desorption treatment device structures and operating parameters that meet the processing time of each temperature stage and the processing volume of each temperature stage is calculated, and the combination of thermal desorption treatment device structures and operating parameters includes: the horizontal inclination angle of the cylinder of the thermal desorption treatment device, the inner diameter of the rotating cylinder, and the rotation speed of the rotating cylinder; The combination of structure and operating parameters with the lowest material consumption and / or the lowest manufacturing cost in the trial calculation results is selected as the final structure and operating parameters of the thermal desorption treatment device.

9. The method according to claim 8, characterized in that The combination of multiple thermal desorption treatment device structures and operating parameters that meet the processing time of each temperature stage and the processing volume of each temperature stage is calculated, including: The combinations of thermal desorption device structures and operating parameters that satisfy the following formula are calculated: When there is no copy board inside the cylinder, the processing time of each temperature stage: τ i =[H i / (πD)](θ+24) / (324Dnsinα); where: θ is the natural inclination angle of the material, which is determined by the design parameters; α is the horizontal inclination angle of the cylinder, which is no more than 6°; D is the inner diameter of the cylinder of the thermal desorption treatment device, and n is the rotation speed of the cylinder; When there is a copy board inside the cylinder, the processing time of each temperature stage: τ i =mk(H i / D) / (Dnsinα); where: m and k are coefficients related to the form of the copy board, the flow direction of the material, the flow direction of the heat carrier, the material density, etc., and they are taken as constants; Processing volume at each temperature stage: m i =[φ i ρ i (H i / π)D] / (2.12×10 -2 Jτ i )=m(1-C i );Wherein: J is the structural influence coefficient, which takes the value of 1.0 when there is no baffle plate or copying plate accessory in the cylinder, takes the value of 1.1-1.2 when there is a baffle plate or copying plate but no other accessories in the cylinder, and takes the value of 1.30-1.45 when there are other accessories in addition to the baffle plate or copying plate in the cylinder.

10. The method according to any one of claims 6 to 9, characterized in that: In the process of trial calculation of the combination of multiple thermal desorption treatment device structures and operating parameters, the following conditions must also be met: The total duration of the thermal desorption treatment is calculated based on the treatment time of each temperature stage, which meets the requirements of the design parameters.

11. A thermal desorption treatment device, characterized in that: The structure and operating parameters of the thermal desorption treatment device are obtained through the design method of the stepped functional thermal desorption treatment device as described in any one of claims 1-10.

12. The device according to claim 11, characterized in that The thermal desorption treatment device is a fixed spiral-propelled thermal desorption treatment device, or a rotary kiln-type thermal desorption treatment device.

13. The device according to claim 11, characterized in that The gas outlet of the thermal desorption treatment device is located at 1 / 3 of the material outlet in each temperature stage.

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