Reaction device for preparing biodiesel from waste grease

Abstract

The utility model belongs to the technical field of biodiesel preparation, and particularly relates to a reaction device for preparing biodiesel from waste grease, which comprises a shell, a temperature adjusting mechanism, a stirring mechanism and an emulsifying mechanism. The temperature adjusting mechanism comprises a jacket, an electric heating pipe and heat exchange pipes, the jacket is filled with heat conduction oil, an emptying opening is formed in the upper portion of the jacket, and the spirally-distributed heat exchange pipes are arranged on the inner wall of the shell. The stirring mechanism comprises a stirring speed reducing motor, a stirring main shaft and two symmetrical expansion brackets; the stirring main shaft is connected with the two symmetrical expansion brackets through connecting rods; the expanding bracket is L-shaped, and a plurality of stirring blades are arranged on the stirring main shaft and the expanding bracket. And the emulsifying mechanism comprises an emulsifying speed reducing motor and an emulsifier. According to the utility model, the stirring structure is improved, so that materials are stirred more sufficiently and quickly, emulsification operation can be realized while heating and stirring are carried out, a mixture of waste grease and a catalyst does not need to be transferred to an emulsifying machine, the operation steps are reduced, and the working efficiency is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of biodiesel preparation, and particularly relates to a reaction device for preparing biodiesel from waste oil. Background Art

[0002] The production of biodiesel from waste oils and fats (such as gutter cooking oil) is an important way to recycle waste and has garnered widespread attention worldwide. Gutter cooking oil and other waste cooking oils are often illegally processed or simply discarded, potentially polluting water and soil. By converting these wastes into biodiesel, these wastes are effectively utilized, reducing environmental pollution. Compared to biodiesel made from edible oils such as soybean oil and rapeseed oil, waste oils and fats offer a cost advantage and do not exacerbate the conflict between food and energy.

[0003] Biodiesel recycles carbon during combustion, emitting 50%-80% less carbon dioxide than fossil diesel, helping to mitigate global warming. Waste oil biodiesel, as a renewable energy source, can partially replace petroleum diesel, reducing dependence on fossil fuels and improving energy security. Furthermore, proper recycling of waste oil prevents its direct discharge into sewers, reduces eutrophication, and reduces the burden of wastewater treatment.

[0004] Our unit has previously disclosed Chinese invention patent CN 107099322 B, a method for preparing biofuel from waste oil and fat and a method for preparing mixed fuels. The entire reaction process effectively removes fatty acids from the cracking products while cracking them, while significantly reducing the recombinant fraction. Furthermore, the process involves fewer reaction and separation steps, resulting in less wastewater and exhaust gas emissions. The process is simple, requires fewer equipment, and produces biomass oil with stable quality and high yield.

[0005] The production process of biodiesel from waste oils requires the batch addition of various reactants, such as anhydrous calcium chloride, olein, and potassium hydroxide solution. The mixture then undergoes stirring, heating, and emulsification to produce a microemulsified waste oil, which can then be pumped into a tubular cracking furnace for cracking. The reactor is the core equipment for the transesterification reaction between the waste oil and the catalyst. However, existing reactors lack precise temperature control and low stirring efficiency. Furthermore, the mixed waste oil must be transferred to a specialized emulsifier for emulsification, resulting in low efficiency. Utility Model Content

[0006] The present invention addresses the aforementioned shortcomings of existing technologies, namely, the inaccurate temperature control and low stirring efficiency of reactors for biodiesel production from waste oils, which prevent simultaneous emulsification and result in low efficiency. The present invention provides a reactor for biodiesel production from waste oils. By modifying the temperature control method, improving the stirring structure, and integrating an emulsifier with the reactor, the reactor reduces the number of steps and improves efficiency.

[0007] In order to achieve the above-mentioned purpose, the utility model provides a reaction device for preparing biodiesel from waste oil, comprising a shell, a temperature regulating mechanism, a stirring mechanism, and an emulsifying mechanism.

[0008] The top of the shell is provided with an end cover that can be opened and closed, and the bottom is provided with multiple legs; the top of the shell is provided with a feed port, and the bottom is provided with a discharge port.

[0009] The temperature regulating mechanism includes a jacket, an electric heating tube, and a heat exchange tube. The jacket is arranged on the outer wall of the lower middle part of the shell, and a plurality of vertically and obliquely distributed electric heating tubes are arranged in the jacket; the interior of the jacket is filled with heat transfer oil, and a vent is provided at the top and an oil drain port is provided at the bottom; a spirally distributed heat exchange tube is arranged on the inner wall of the shell, and a refrigerant inlet and a refrigerant outlet are provided at both ends of the heat exchange tube, which penetrate the shell and the jacket.

[0010] The stirring mechanism includes a stirring reduction motor, a stirring main shaft, and an expansion bracket. The stirring reduction motor is installed on the top of the end cover, and a sealing structure is provided at the connection with the end cover. The stirring reduction motor is connected to the stirring main shaft, which is vertically arranged. The stirring main shaft is connected to two symmetrical expansion brackets through a connecting rod; the expansion bracket is L-shaped, and the lower part extends toward the stirring main shaft; a plurality of stirring blades are provided on the stirring main shaft and the expansion bracket.

[0011] The emulsifying mechanism includes an emulsifying reduction motor and an emulsifier. The emulsifier is installed on the inner wall of the bottom of the shell. The emulsifying reduction motor installed outside the bottom of the shell is connected to the emulsifier. The stirring main shaft, expansion bracket and stirring blades thereof avoid the emulsifier.

[0012] According to another embodiment of the present invention or the reaction device of any of the aforementioned embodiments, the stirring main shaft and the bottom of the expansion bracket are close to and surround the emulsifier.

[0013] According to another embodiment of the present invention or the reaction device of any of the aforementioned embodiments, the end cover is provided with a manhole, a pressure gauge interface, a glass window, a vacuum hole, a distillation hole, a feed port, and a thermocouple socket.

[0014] According to another embodiment of the present invention or the reaction device of any of the aforementioned embodiments, the discharge port avoids the emulsifier and the emulsification reduction motor, the discharge port is not located at the center of the bottom, and the bottom of the shell is flat.

[0015] According to another embodiment of the present invention or the reaction device of any of the aforementioned embodiments, the refrigerant inlet is connected to the bottom end of the heat exchange tube, and the refrigerant outlet is connected to the top end of the heat exchange tube.

[0016] According to another embodiment of the present invention or the reaction device of any of the aforementioned embodiments, an oil overflow cylinder is connected to the upper portion of the jacket to temporarily store the expanded and overflowed thermal oil.

[0017] According to another embodiment of the present invention or a reaction device of any of the aforementioned embodiments, the stirring blades are not arranged vertically, but are arranged obliquely on the stirring main shaft and the expansion bracket, in groups of two, and the stirring main shaft and the expansion bracket are respectively provided with more than two groups, which are welded on both sides of the main body of the stirring main shaft and the expansion bracket, and the stirring blades on the stirring main shaft and the stirring blades on the expansion bracket are staggered.

[0018] According to another embodiment of the present invention or the reaction device of any of the aforementioned embodiments, the stirring reduction motor and the emulsification reduction motor include a reduction gear and a drive motor.

[0019] Beneficial effects of the utility model:

[0020] 1. The reaction device for preparing biodiesel from waste oils and fats of the present invention has an improved stirring structure. Extension brackets are provided on both sides of the stirring main shaft. The extension brackets are L-shaped. Multiple stirring blades distributed obliquely are provided on the stirring main shaft and the extension brackets, so that the materials are stirred more fully and quickly, the stirring uniformity is improved, and the stirring time is reduced.

[0021] 2. The utility model reserves an emulsifier installation space at the bottom of the stirring mechanism, and adjusts the position of the discharge port accordingly, so that the emulsification operation can be achieved while heating and stirring. There is no need to transfer the mixture of waste oil and catalyst to the emulsifier, which reduces the operation steps and improves work efficiency.

[0022] 3. The utility model provides a jacket on the outside of the shell, which is filled with heat-conducting oil, and multiple electric heating tubes are provided in the heat-conducting oil. An insulation layer is provided on the outside of the jacket, which saves more energy. A heat exchange tube is provided on the inner wall of the shell, and a circulating refrigerant is connected to the heat exchange tube. The temperature is controlled more accurately by thermocouples, electric heating tubes and heat exchange tubes to improve reaction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of part of the process principle of the reaction device involved in preparing biodiesel from waste oil according to the present invention;

[0024] Figure 2 This is a partial cross-sectional schematic diagram of the reaction device for preparing biodiesel from waste oil according to the present invention;

[0025] Figure 3 This is an enlarged schematic diagram of the stirring mechanism main body of the present utility model;

[0026] In the picture:

[0027] 1. Stirring reduction motor; 2. Stirring main shaft; 3. Jacket; 4. Oil drain port; 5. Discharge port; 6. Emulsification reduction motor; 7. Emulsifier; 8. Refrigerant inlet; 9. Refrigerant outlet; 10. Heat exchange tube; 11. Oil overflow cylinder; 12. Expansion bracket; 13. Stirring blades; 14. Shell; 15. Insulation layer; 16. Connecting rod. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0029] like Figure 2 As shown, a reaction device for preparing biodiesel from waste oil, comprising a housing 14, a temperature regulating mechanism, a stirring mechanism, and an emulsifying mechanism.

[0030] like Figure 2 As shown, the housing 14 has an openable and closable end cap at the top and multiple legs at the bottom. The housing 14 has a feed port at the top and a discharge port 5 at the bottom. The end caps are equipped with a manhole, a pressure gauge port, a glass window, a vacuum port, a distillation port, a feed port, and a thermocouple socket. The discharge port 5 is positioned away from the emulsifier 7 and the emulsification reduction motor 6 and is not located at the center of the bottom. The bottom of the housing 14 is flat.

[0031] like Figure 2 As shown, the temperature control mechanism includes a jacket 3, electric heating tubes, and heat exchange tubes 10. The jacket 3 is mounted on the outer wall of the lower middle portion of the housing 14. Multiple electric heating tubes are arranged vertically and diagonally within the jacket 3. The jacket 3 is filled with thermal oil and has a vent at the top and an oil drain port 4 at the bottom. An oil overflow cylinder 11 is connected to the top of the jacket 3 to temporarily store expanded and overflowing thermal oil. The heat exchange tubes 10 are spirally arranged on the inner wall of the housing 14. Both ends of the heat exchange tubes 10 are provided with a refrigerant inlet 8 and a refrigerant outlet 9, which extend through the housing 14 and the jacket 3. The refrigerant inlet 8 is connected to the bottom end of the heat exchange tubes 10, and the refrigerant outlet 9 is connected to the top end of the heat exchange tubes 10.

[0032] like Figure 2 、 3As shown, the stirring mechanism includes a stirring reduction motor 1, a stirring main shaft 2, and an expansion bracket 12. The stirring reduction motor 1 is installed on the top of the end cover, and a sealing structure is provided at the connection with the end cover. The stirring reduction motor 1 is connected to the stirring main shaft 2, which is vertically arranged. The stirring main shaft 2 is connected to two symmetrical expansion brackets 12 through a connecting rod 16; the expansion bracket 12 is L-shaped, and the lower part extends toward the stirring main shaft 2; a plurality of stirring blades 13 are provided on the stirring main shaft 2 and the expansion bracket 12. The stirring blades 13 are not vertically arranged, but obliquely arranged on the stirring main shaft 2 and the expansion bracket 12, in groups of two. The stirring main shaft 2 and the expansion bracket 12 are respectively provided with two or more groups, which are welded on both sides of the main body of the stirring main shaft 2 and the expansion bracket 12. The stirring blades 13 on the stirring main shaft 2 and the stirring blades 13 on the expansion bracket 12 are staggered.

[0033] like Figure 2 As shown, the emulsification mechanism includes an emulsification reduction motor 6 and an emulsifier 7. The emulsifier 7 is installed on the inner wall of the bottom of the shell 14. The emulsification reduction motor 6 installed on the outside of the bottom of the shell 14 is connected to the emulsifier 7. The stirring shaft 2, the expansion bracket 12 and the stirring blades 13 avoid the emulsifier 7. The bottom of the stirring shaft 2 and the expansion bracket 12 are close to and surround the emulsifier 7.

[0034] The stirring reduction motor 1 and the emulsifying reduction motor 6 include a reduction gear and a driving motor.

[0035] The working principle of this utility model:

[0036] like Figure 1 、 2 As shown, in the process of preparing biodiesel from waste oil and grease, the transesterification reaction is most effective within a certain temperature range. Excessively high temperatures may lead to side reactions (such as saponification reactions) and the generation of undesirable by-products. The utility model can dissipate heat in a timely manner by providing a heat exchange tube 10, thereby avoiding excessive temperatures in the reactor, preventing the ester catalyst from being deactivated, maintaining ideal reaction conditions, and improving the selectivity of the reaction and the yield of biodiesel. In the later stage of the reaction, when the system needs to be cooled, the heat exchange tube 10 connected to the circulating refrigerant can efficiently take away excess heat, which has lower energy consumption than other cooling methods and saves production costs.

[0037] The present invention provides an insulation layer 15 outside the jacket 3 filled with thermal oil, effectively reducing heat loss from the reactor heating jacket 3 to the outside world, thereby improving thermal efficiency, reducing energy consumption, and lowering production costs. The biodiesel production process requires operation within a specific temperature range. The insulation layer 15 reduces the impact of external temperature fluctuations, ensuring a more stable reaction temperature, thereby improving reaction efficiency and product quality.

[0038] The stirring shaft and the expansion bracket 12 of the utility model are provided with a plurality of blades, and the blades are arranged obliquely, which can produce a three-dimensional stirring effect during the rotation process, so that the liquid in the reactor forms an up-down, left-right, and radial flow, and prevents the liquid from rotating only along the horizontal plane. The oblique blades can enhance the convection movement of the fluid during stirring, make the heat distribution in the reactor more uniform, avoid local overheating or insufficient temperature, ensure the consistency of reaction conditions, and help improve the quality of the product. Due to the high viscosity of waste oil and grease, stratification or sedimentation is prone to occur. The blade design of the utility model can generate a large shear force and turbulent effect, effectively break the stratification, prevent deposition at the bottom of the reaction device, and maintain the active state of the entire reaction system. Uniform stirring and good heat transfer effect can promote the contact between oil and catalyst and improve production efficiency.

[0039] The utility model is provided with an emulsifier 7 at the lower part of the stirring mechanism. After heating and stirring, the mixture of waste oil and catalyst does not need to be transferred to the emulsifier. By adding an emulsifier, the waste oil and catalyst can be fully mixed in the reaction device to form a fine emulsion. This uniform dispersion state helps to increase the contact area of ​​the phase interface, improve the reaction efficiency, and promote the progress of the transesterification reaction.

[0040] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the above embodiments are merely illustrative of the technical concepts and features of the present invention, and are intended to enable those familiar with the art to understand and implement the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications based on the spirit and substance of the present invention are intended to fall within the scope of protection of the present invention.

Claims

1. A reaction device for preparing biodiesel from waste oils and fats, characterized by: It includes a shell (14), a temperature regulating mechanism, a stirring mechanism, and an emulsifying mechanism. The shell (14) is provided with an openable and closable end cover at the top and a plurality of legs at the bottom; the shell (14) is provided with a feed port at the top and a discharge port (5) at the bottom. The temperature regulating mechanism comprises a jacket (3), an electric heating tube, and a heat exchange tube (10). The jacket (3) is arranged on the outer wall of the lower middle part of the shell (14), and a plurality of vertically and obliquely distributed electric heating tubes are arranged in the jacket (3); the jacket (3) is filled with heat transfer oil, and an air discharge port is provided at the top and an oil discharge port (4) is provided at the bottom; the inner wall of the shell (14) is provided with a spirally distributed heat exchange tube (10), and a refrigerant inlet (8) and a refrigerant outlet (9) are provided at both ends of the heat exchange tube (10) and pass through the shell (14) and the jacket (3). The stirring mechanism comprises a stirring reduction motor (1), a stirring main shaft (2), and an expansion bracket (12); the stirring reduction motor (1) is mounted on the top of the end cover, and a sealing structure is provided at the connection with the end cover; the stirring reduction motor (1) is connected to the stirring main shaft (2); the stirring main shaft (2) is vertically arranged, and the stirring main shaft (2) is connected to two symmetrical expansion brackets (12) through a connecting rod (16); the expansion bracket (12) is L-shaped, and the lower part extends toward the stirring main shaft (2); a plurality of stirring blades (13) are provided on the stirring main shaft (2) and the expansion bracket (12); The emulsifying mechanism comprises an emulsifying reduction motor (6) and an emulsifier (7). The emulsifier (7) is mounted on the inner wall of the bottom of the housing (14). The emulsifying reduction motor (6) mounted on the outside of the bottom of the housing (14) is connected to the emulsifier (7). The stirring main shaft (2), the expansion bracket (12) and the stirring blade (13) thereof avoid the emulsifier (7).

2. The reaction device for preparing biodiesel from waste oils and fats according to claim 1, characterized in that: The bottom of the stirring main shaft (2) and the expansion bracket (12) are close to and surround the emulsifier (7).

3. The reaction device for preparing biodiesel from waste oils and fats according to claim 1, characterized in that: The end cover is provided with a manhole, a pressure gauge interface, a glass window, a vacuum hole, a distillation hole, a feed port, and a thermocouple socket.

4. The reaction device for preparing biodiesel from waste oils and fats according to claim 1, characterized in that: The discharge port (5) avoids the emulsifier (7) and the emulsifying reduction motor (6), the discharge port (5) is not located at the bottom center, and the bottom of the shell (14) is flat.

5. The reaction device for preparing biodiesel from waste oils and fats according to claim 1, characterized in that: The refrigerant inlet (8) is connected to the bottom end of the heat exchange tube (10), and the refrigerant outlet (9) is connected to the top end of the heat exchange tube (10).

6. The reaction device for preparing biodiesel from waste oils and fats according to claim 1, characterized in that: The upper part of the jacket (3) is connected to an oil overflow cylinder (11) for temporarily storing expanded and overflowed heat transfer oil.

7. The reaction device for preparing biodiesel from waste oils and fats according to claim 1, characterized in that: The stirring blades (13) are not arranged vertically, but are arranged obliquely on the stirring main shaft (2) and the expansion bracket (12), in groups of two. The stirring main shaft (2) and the expansion bracket (12) are respectively provided with two or more groups, which are welded on both sides of the main body of the stirring main shaft (2) and the expansion bracket (12). The stirring blades (13) on the stirring main shaft (2) and the stirring blades (13) on the expansion bracket (12) are staggered.

8. The reaction device for preparing biodiesel from waste oils and fats according to claim 1, characterized in that: The stirring reduction motor (1) and the emulsifying reduction motor (6) comprise a reduction gear and a driving motor.

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