Waste heat recovery structure of fluidized bed roaster

Abstract

The utility model discloses a waste heat recovery structure of a fluidized bed roaster, which comprises a sand conveying pipe used for conveying sand, the sand conveying pipe is connected with the fluidized bed roaster, the fluidized bed roaster is connected with a heat preservation sand bin through a valve capable of being opened and closed, the heat preservation sand bin is connected to a boiling cooling bed, and the waste heat recovery structure further comprises a multi-stage waste heat recovery structure, the heat recovery device comprises a heat recovery pipe arranged on the boiling cooling bed, the heat recovery pipe is connected with a first filter cartridge, a heat circulating pipe is arranged at the top of the heat preservation sand bin, the first filter cartridge is connected with the heat circulating pipe through a connecting pipe, the connecting pipe is communicated to a relay cylinder, and the relay cylinder is connected to a sand conveying pipe through a bent pipe. Heat overflowing from the boiling cooling bed is conveyed to the sand conveying pipe, finished sand is preheated in the heat preservation sand bin, hot air discharged by the boiling cooling bed can be circulated to the front end of the boiling roasting furnace to fully preheat molding sand, and energy consumption is reduced.

Description

Technical Field

[0001] The utility model relates to a waste heat recovery structure, in particular to a waste heat recovery structure of a fluidized bed roasting furnace. Background Art

[0002] When performing sand casting, it is often necessary to recycle and reuse the old sand. In the process of recycling the old sand, the sand needs to be heated to a certain temperature in a fluidized bed roasting furnace to remove some impurities therein, and then the high-temperature old sand is quickly restored to a certain temperature for standby use through a fluidized bed cooling bed, so that the collected waste sand can meet the standards for mixing with other mixtures, and the sand casting mold that meets the composite requirements can be re-made.

[0003] In the existing molding sand recovery process, the molding sand at room temperature needs to be heated to a high temperature to remove impurities in the roasting furnace stage, which consumes a lot of energy. In the boiling cooling bed, a lot of energy is needed to cool the molding sand. The whole process back and forth consumes a lot of energy. In addition, the hot air discharged from the boiling cooling bed carries molding sand particles, which not only pollutes the environment, but also completely loses the heat energy. In addition, the hot air is discharged into the external environment, and an insulation structure needs to be set up for isolation. Although the entire recovery process achieves the purpose of recovery, the loss is extremely large and it is very easy to cause pollution.

[0004] Therefore, this case aims to provide a waste heat recovery structure of a fluidized bed roasting furnace, which can circulate the hot air discharged from the fluidized bed to the front end of the fluidized bed roasting furnace to fully preheat the molding sand, thereby reducing the heat energy consumed by the fluidized bed roasting furnace, and can effectively utilize the hot air discharged from the fluidized bed to form an internal circulation, thereby avoiding pollution in an internal circulation manner. Utility Model Content

[0005] The utility model provides a residual heat recovery structure of a fluidized bed roasting furnace, which can effectively solve the above-mentioned problem.

[0006] The utility model is achieved in this way:

[0007] A fluidized bed roasting furnace waste heat recovery structure, comprising: a sand conveying pipe for conveying sand, the sand conveying pipe is connected to a fluidized bed roasting furnace, the fluidized bed roasting furnace is connected to a heat preservation sand storage through an openable and closable valve, the heat preservation sand storage is connected to a fluidized bed cooling bed, and further comprising:

[0008] The multi-stage waste heat recovery structure includes a heat recovery pipe arranged on the boiling cooling bed, the heat recovery pipe is connected to a first filter cylinder, a heat circulation pipe is arranged on the top of the thermal insulation sand storage, the first filter cylinder and the heat circulation pipe are connected by a connecting pipe, the connecting pipe is connected to a relay cylinder, and the relay cylinder is connected to the sand conveying pipe through a bent pipe, so that the heat overflowed from the boiling cooling bed is transported to the sand conveying pipe and the thermal insulation sand storage to preheat the finished sand.

[0009] As a further improvement, the relay tube includes a first conduit connected to the fluidized bed roasting furnace and a second conduit connected to the thermal insulation sand storehouse, and the first conduit and the second conduit are connected via a heat transfer tank.

[0010] As a further improvement, a plurality of inclined guide plates are arranged inside the sand conveying pipe, and the plurality of inclined guide plates are arranged alternately and at intervals.

[0011] As a further improvement, a plurality of dispersion edges are provided on the upper surface of the inclined guide plate, the dispersion edges are arranged at intervals, and a plurality of small holes are provided on the inner side of the dispersion edges.

[0012] As a further improvement, a top disperser is provided at the top of the end of the bending tube, and a bottom disperser is provided at the bottom of the bending tube. Both the top disperser and the bottom disperser are communicated with the sand conveying pipe, and the top disperser and the bottom disperser evenly distribute the hot air into the sand conveying pipe.

[0013] As a further improvement, the top disperser comprises a bearing box communicated with the top of the bending pipe, and two injection pipe columns are arranged on one side of the bearing box close to the sand conveying pipe, and the injection pipe columns are communicated with the sand conveying pipe.

[0014] As a further improvement, the bottom disperser comprises a plurality of groups of material conveying partitions, and each layer of the material conveying partition corresponds to the inclined guide plate.

[0015] The beneficial effects of the utility model are:

[0016] In the existing sand recovery process, whether it is the temperature of the roasting furnace or the cooling bed, if it is not utilized, its hot air and temperature are lost in vain, and the roasting furnace always needs to provide a large amount of thermal energy. Therefore, the utility model can collect the heat overflowed during the cooling of the boiling cooling bed through the heat recovery pipe through the added multi-stage waste heat recovery structure, and supply part of the heat to the insulation sand warehouse to retain the temperature of the insulation sand warehouse, and most of the heat is transported to the sand conveying pipe through the bending pipe to preheat the molding sand that is about to enter the boiling roasting furnace, thereby greatly reducing the combustion time and energy consumption of the boiling roasting furnace, and using the heat that will inevitably be lost to reduce the energy consumption of the boiling roasting furnace, which not only reduces the front-end heating cost, but also avoids the addition of a separate insulation structure, and does not require a separate isolation means for hot gas discharge. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solution of the implementation mode of the utility model, the drawings required for use in the implementation mode will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 The utility model is a structural schematic diagram of a waste heat recovery structure of a boiling roasting furnace.

[0019] Figure 2 The utility model is a schematic diagram of the internal structure of a sand conveying pipe.

[0020] Figure 3 It is a schematic diagram of the top view structure of an inclined guide plate of the utility model.

[0021] In the figure:

[0022] Sand conveying pipe 10, inclined guide plate 11, dispersing rib 111, boiling roasting furnace 20, insulation sand storage 30, boiling cooling bed 40, heat recovery pipe 51, first filter cartridge 52, heat circulation pipe 53, connecting pipe 54, relay cartridge 55, first conduit 551, second conduit 552, heat transfer tank 553, bending pipe 56, top disperser 57, carrying box 571, infusion column 572, bottom disperser 58, material conveying partition 581. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the utility model. Therefore, the following detailed description of the embodiments of the utility model provided in the drawings is not intended to limit the scope of the utility model for which protection is sought, but merely represents the selected embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the utility model.

[0024] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0025] Reference Figure 1 to Figure 3 As shown, a fluidized bed roasting furnace waste heat recovery structure comprises: a sand conveying pipe 10 for conveying sand, the sand conveying pipe 10 is connected to a fluidized bed roasting furnace 20, the fluidized bed roasting furnace 20 is connected to an insulation sand storehouse 30 through an openable and closable valve, the insulation sand storehouse 30 is connected to a fluidized bed cooling bed 40, and also comprises: a multi-stage waste heat recovery structure, comprising a heat recovery pipe 51 arranged on the fluidized bed cooling bed 40, the heat recovery pipe 51 is connected to a first filter cartridge 52, a heat circulation pipe 53 is arranged on the top of the insulation sand storehouse 30, the first filter cartridge 52 is connected to the heat circulation pipe 53 through a connecting pipe 54, the connecting pipe 54 is connected to a relay cartridge 55, the relay cartridge 55 is connected to the sand conveying pipe 10 through a bending pipe 56, and the heat overflowing from the fluidized bed 40 is conveyed to the sand conveying pipe 10 and the insulation sand storehouse 30 to preheat the finished sand.

[0026] The entire flow path of the molding sand is to pass the used molding sand into the boiling roasting furnace 20 through the sand conveying pipe 10, and the impurities in the waste sand are removed by the boiling roasting furnace 20 at high temperature. The molding sand after impurities are removed is stored in the insulation sand warehouse 30 for insulation, and then passed into the boiling cooling bed 40 for cooling before use when needed.

[0027] In the existing molding sand recovery process, whether it is the temperature of the roasting furnace or the cooling bed, if it is not utilized, its hot air and temperature are lost in vain, and the roasting furnace always needs to provide a large amount of thermal energy. Therefore, the utility model can collect the heat overflowed when the boiling cooling bed 40 is cooled through the heat recovery pipe 51 through the added multi-stage waste heat recovery structure, and supply part of the heat to the insulation sand warehouse 30 to retain the temperature of the insulation sand warehouse 30, and most of the heat is transported to the sand conveying pipe 10 through the bending pipe 56 to preheat the molding sand that is about to enter the boiling roasting furnace 20, thereby greatly reducing the combustion time and energy consumption of the boiling roasting furnace 20, and using the heat that will inevitably be lost to reduce the energy consumption of the boiling roasting furnace 20, not only reducing the front-end heat cost, but also avoiding the addition of a separate insulation structure, and no separate isolation means for hot gas discharge is required.

[0028] In this embodiment, the sand input into the insulating sand storage 30 accounts for about 20% of the recovered heat, while the heat input into the sand conveying pipe 10 accounts for 80% of the recovered heat, thereby achieving a two-stage purpose of recovering heat.

[0029] After the entire heating process is completed, a certain amount of heat still remains in the boiling roasting furnace 20. Therefore, in this case, a relay tube 55 is set up, and the relay tube 55 includes a first conduit 551 connected to the boiling roasting furnace 20, and a second conduit 552 connected to the insulation sand storage 30. The first conduit 551 and the second conduit 552 are connected by a heat transfer tank 553, so that the residual heat of the boiling roasting furnace 20 can be transported to the insulation sand storage 30, and the residual heat in the heat transfer tank 553 can be completely transported to the insulation sand storage 30.

[0030] In this embodiment, the heat is in the form of hot air and is pumped.

[0031] After the heat enters the sand conveying pipe 10 through the multi-stage waste heat recovery structure, in order to improve the contact efficiency between the heat and the molding sand, a plurality of inclined guide plates 11 are arranged inside the sand conveying pipe 10. The plurality of inclined guide plates 11 are arranged alternately at intervals. The plurality of inclined guide plates 11 can greatly retain the downward movement speed of the molding sand, increase the contact time with the heat, thereby increasing the initial temperature of the molding sand and reducing the energy consumption at the rear end.

[0032] In order to increase the contact area between heat and molding sand, a plurality of dispersion ridges 111 are provided on the upper surface of the inclined guide plate 11. The dispersion ridges 111 are arranged at intervals, and a plurality of small holes are provided on the inner side of the dispersion ridges 111. Hot air can come out from the small holes, so as to be able to fully contact with the molding sand.

[0033] In order to distribute the heat input into the sand conveying pipe 10 more evenly, a top disperser 57 is provided at the top of the end of the bending pipe 56, and a bottom disperser 58 is provided at the bottom of the bending pipe 56. The top disperser 57 and the bottom disperser 58 are both connected to the sand conveying pipe 10, and the top disperser 57 and the bottom disperser 58 evenly distribute the hot air into the sand conveying pipe 10. The hot air can be dispersed more evenly through the middle input and the upper and lower top dispersers 57 and bottom dispersers 58.

[0034] Among them, the top disperser 57 includes a carrying box 571 connected to the top of the bending tube 56. Two injection pipe columns 572 are arranged on the side of the carrying box 571 close to the sand conveying pipe 10. The injection pipe columns 572 are connected to the sand conveying pipe 10. Through the transportation method of the two sections of the injection pipe columns 572, the heat in the carrying box 571 is more evenly input into the top position inside the sand conveying pipe 10.

[0035] At the lower end of the sand conveying pipe 10, the bottom disperser 58 includes a plurality of groups of material conveying partitions 581, each layer of the material conveying partition 581 corresponds to the inclined guide plate 11, and the hot air is directly input to the inner side of the inclined guide plate 11 through the material conveying partition 581 and output through the small holes, so that the hot air in the lower half of the sand conveying pipe 10 can be evenly output from the position of the inclined guide plate 11, which is better matched with the hot air structure.

[0036] In fact, when the bent pipe 56 delivers gas, a part of it is directly output from the outlet of the bent pipe 56, so that the top disperser 57 can initially contact the molding sand entering the sand conveying pipe 10, and further mix with the hot air output from the bent pipe 56 in the middle, and finally fully mix at the position of the material conveying partition 581, so as to achieve the purpose of preliminary heating of the molding sand.

[0037] The above description is only the preferred implementation of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A fluidized bed roasting furnace waste heat recovery structure, characterized in that: include: A sand conveying pipe (10) for conveying sand, the sand conveying pipe (10) is connected to a fluidized bed roasting furnace (20), the fluidized bed roasting furnace (20) is connected to a heat preservation sand storehouse (30) through an openable and closable valve, the heat preservation sand storehouse (30) is connected to a fluidized bed cooling bed (40), and further comprises: A multi-stage waste heat recovery structure comprises a heat recovery pipe (51) arranged on the boiling cooling bed (40), the heat recovery pipe (51) is connected to a first filter cartridge (52), a heat circulation pipe (53) is arranged on the top of the thermal insulation sand storage (30), the first filter cartridge (52) and the heat circulation pipe (53) are connected via a connecting pipe (54), the connecting pipe (54) is connected to a relay tube (55), and the relay tube (55) is connected to a sand conveying pipe (10) via a bending pipe (56), so as to convey the heat overflowing from the boiling cooling bed (40) to the sand conveying pipe (10) and the thermal insulation sand storage (30) to preheat the finished sand.

2. A fluidized bed roasting furnace waste heat recovery structure according to claim 1, characterized in that: The relay tube (55) includes a first conduit (551) connected to the fluidized bed roasting furnace (20), and a second conduit (552) connected to the thermal insulation sand storage (30), and the first conduit (551) and the second conduit (552) are connected via a heat transfer tank (553).

3. The waste heat recovery structure of a fluidized bed roasting furnace according to claim 1, characterized in that: A plurality of inclined guide plates (11) are arranged inside the sand transport pipe (10), and the plurality of inclined guide plates (11) are arranged alternately and at intervals.

4. A fluidized bed roasting furnace waste heat recovery structure according to claim 3, characterized in that: The upper surface of the inclined guide plate (11) is provided with a plurality of dispersion edges (111), the dispersion edges (111) are arranged at intervals, and a plurality of small holes are arranged on the inner side of the dispersion edges (111).

5. A fluidized bed roasting furnace waste heat recovery structure according to claim 4, characterized in that: A top disperser (57) is arranged at the top of the end of the bending tube (56), and a bottom disperser (58) is arranged at the bottom of the bending tube (56). The top disperser (57) and the bottom disperser (58) are both connected to the sand conveying pipe (10), and the top disperser (57) and the bottom disperser (58) evenly distribute the hot air into the sand conveying pipe (10).

6. A fluidized bed roasting furnace waste heat recovery structure according to claim 5, characterized in that: The top disperser (57) comprises a bearing box (571) in communication with the top of the bending tube (56), and two injection pipe columns (572) are arranged on one side of the bearing box (571) close to the sand conveying pipe (10), and the injection pipe columns (572) are in communication with the sand conveying pipe (10).

7. The waste heat recovery structure of a fluidized bed roasting furnace according to claim 5, characterized in that: The bottom disperser (58) comprises a plurality of groups of material conveying partitions (581), and each layer of the material conveying partition (581) corresponds to the inclined guide plate (11).

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