阅读说明：本技术 高效煤粉预加热装置 (High-efficient buggy preheating device ) 是由 王宏强 于 2021-03-04 设计创作，主要内容包括：本发明提出高效煤粉预加热装置,属于固气两相流换热技术领域；具体为管状结构,管状结构内沿轴向设置有螺旋状导流片和换热组件,换热组件轴向贯穿于螺旋状导流片；换热组件包括换热管,换热管外壁固定有螺旋翅片,在螺旋翅片外套设有套管,套管设置在螺旋翅片与螺旋状导流片的交接处,套管与螺旋状导流片固定连接；本发明使高温烟气在预热装置中与煤加热管充分、均匀换热,无气流死角,换热效率提高。(The invention provides an efficient pulverized coal preheating device, belonging to the technical field of solid-gas two-phase flow heat exchange; the heat exchanger is of a tubular structure, wherein a spiral flow deflector and a heat exchange assembly are axially arranged in the tubular structure, and the heat exchange assembly axially penetrates through the spiral flow deflector; the heat exchange component comprises a heat exchange tube, spiral fins are fixed on the outer wall of the heat exchange tube, sleeves are sleeved outside the spiral fins and are arranged at the joints of the spiral fins and the spiral flow deflectors, and the sleeves are fixedly connected with the spiral flow deflectors; the invention ensures that the high-temperature flue gas and the coal heating pipe can fully and uniformly exchange heat in the preheating device, no air flow dead angle exists, and the heat exchange efficiency is improved.)

1. The efficient pulverized coal preheating device is characterized by being of a tubular structure, wherein a flue gas inlet (1) and a flue gas outlet (2) are formed in the wall of the tubular structure, a spiral flow deflector (3) and a heat exchange assembly are axially arranged in the tubular structure, and the heat exchange assembly axially penetrates through the spiral flow deflector (3) along the tubular structure; the heat exchange assembly comprises a heat exchange tube (4), the outer wall of the heat exchange tube (4) is fixed with a spiral fin (5), a sleeve (6) is sleeved outside the spiral fin (5), the sleeve (6) is arranged at the joint of the spiral fin (5) and the spiral flow deflector (3), and the sleeve (6) is fixedly connected with the spiral flow deflector (3).

2. The high-efficiency pulverized coal preheating device according to claim 1, wherein a hollow support tube (7) is axially arranged at the center of the tubular structure; the spiral flow deflector (3) is arranged around the hollow supporting pipe (7) and is fixedly connected with the hollow supporting pipe (7).

3. The high-efficiency pulverized coal preheating device according to claim 2, wherein both ends of the hollow support tube (7) are of a closed structure.

4. The device for preheating pulverized coal as claimed in claim 3, wherein a spacer tube (8) is connected between two adjacent spiral pieces of the spiral deflector (3).

5. The high-efficiency pulverized coal preheating device according to claim 1, wherein a plurality of heat exchange assemblies are uniformly distributed in the tubular structure from a central axis to an outer circumference.

6. The high-efficiency pulverized coal preheating device according to claim 1, wherein the heat exchange tube (4) and the sleeve (6) are movably arranged.

7. The high-efficiency pulverized coal preheating device according to claim 1, wherein the spiral fins (5) are arranged along the axial direction of the heat exchange tube (4).

8. The efficient pulverized coal preheating device according to claim 1, wherein the tubular structure is formed by combining a plurality of sections of tubular shells, and each section of tubular shell is formed by buckling an upper shell and a lower shell which are arranged along the axial direction.

9. The high-efficiency pulverized coal preheating device according to claim 1 or 8, wherein the outer wall of the tubular structure is provided with an insulating layer.

Technical Field

The invention belongs to the technical field of solid-gas two-phase flow heat exchange, and relates to a high-efficiency pulverized coal preheating device.

Background

In the existing steel smelting technology, blast furnace coal powder blowing technology is widely applied, wherein pulverized blast furnace coal powder is pulverized anthracite powder or bituminous coal powder or mixed coal powder of the pulverized anthracite powder and the bituminous coal powder which are filled into a blowing tank, and the pulverized anthracite powder or bituminous coal powder is sprayed into a tuyere from a blast furnace belly pipe through a blowing pipe and a spray gun after being pressurized and fluidized to enter a furnace for combustion so as to replace part of coke to play a role in providing heat and reducing agent, thereby reducing coke ratio and pig iron cost. In order to improve the burning-out rate of the pulverized coal in the furnace, a method for preheating the pulverized coal mixed airflow is adopted, so that the pulverized coal combustion efficiency is improved, and the effects of energy conservation and consumption reduction are achieved.

The prior blast furnace coal powder preheating and blowing technology has the following patent numbers: ZL201410199738.5 and ZL201721216833.7 adopt square box structure, the crisscross heat exchange device of baffle, have following shortcoming: 1. the back of the partition plate has airflow dead corners, and high-temperature flue gas cannot effectively heat the coal passing pipe at the back of the partition plate, so that the heat exchange area is reduced; 2. when the high-temperature flue gas passes through the existing preheating device, the resistance is higher, and the energy consumption of the circulating fan is higher; 3. the heat exchange device with the square structure has poor structural stability and high external heat insulation difficulty, particularly, heat insulation materials on the surface of a vertical face are difficult to install and fix, and meanwhile, the mechanical strength of the upper part of the square pipeline is low, reinforcing ribs need to be added, so that the manufacturing cost and the equipment weight are increased.

Disclosure of Invention

The invention overcomes the defects of the prior art and provides a high-efficiency coal powder preheating device. The purpose is to improve the efficiency of heating the pulverized coal.

In order to achieve the above object, the present invention is achieved by the following technical solutions.

The efficient pulverized coal preheating device is of a tubular structure, a flue gas inlet and a flue gas outlet are formed in the pipe wall of the tubular structure, a spiral flow deflector and a heat exchange assembly are axially arranged in the tubular structure, and the heat exchange assembly axially penetrates through the spiral flow deflector along the tubular structure; the heat exchange assembly comprises a heat exchange tube, spiral fins are fixed on the outer wall of the heat exchange tube, a sleeve is sleeved outside the spiral fins, the sleeve is arranged at the joint of the spiral fins and the spiral flow deflectors, and the sleeve is fixedly connected with the spiral flow deflectors.

Further, a hollow supporting tube is axially arranged in the center of the tubular structure; the spiral flow deflector is arranged around the hollow supporting tube and is fixedly connected with the hollow supporting tube.

Furthermore, two ends of the hollow supporting tube are of closed structures.

Furthermore, a distance pipe is connected between two adjacent spiral pieces of the spiral flow deflector.

Furthermore, a plurality of heat exchange assemblies are uniformly distributed in the tubular structure from the central axis to the outer circumference.

Further, the heat exchange tube and the sleeve are movably arranged.

Further, the spiral fins are arranged along the axial direction of the heat exchange tube.

Furthermore, the tubular structure is formed by combining a plurality of sections of tubular shells, and each section of tubular shell is formed by buckling an upper shell and a lower shell which are arranged along the axial direction.

Further, the outer wall of the tubular structure is provided with a heat insulating layer.

Compared with the prior art, the invention has the beneficial effects that.

Because the heat exchange device adopts the spiral flow deflector, the high-temperature flue gas and the coal heating pipe fully and uniformly exchange heat in the preheating device, no air flow dead angle exists, the heat exchange efficiency is improved, and the pulverized coal can be rapidly heated to the critical ignition point of the pulverized coal from about 40 ℃ to about 350 ℃ within 3 seconds.

The spiral fins are arranged on the outer wall of the heat exchange tube, so that the heat exchange area of the heat exchange tube can be effectively increased, and the heat exchange efficiency is improved; the sleeve is fixedly connected with the spiral flow deflector, so that the interference of the spiral fin and the spiral flow deflector caused by expansion with heat and contraction with cold is effectively prevented, and the heat exchange tube can be adjusted within a certain range.

Compared with the prior art, the heat exchanger has the advantages that the volume is reduced, the strength is improved, and due to the adoption of the round tubular structure, the heat insulation material on the outer wall is convenient to install, and the fixing effect is good. Because the supporting pipe is arranged in the middle of the coal dust preheating device, the spiral flow deflector is firmer in structure, high-temperature flue gas is more uniformly distributed in the spiral flue, the heat conduction efficiency is improved, the flow resistance of the flue gas is reduced, the operation efficiency of the whole coal dust preheating process is improved, and the energy-saving effect is more obvious.

Drawings

In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the following drawings are taken for illustration:

FIG. 1 is a perspective view showing the construction of a pulverized coal preheating apparatus according to an embodiment.

Fig. 2 is a distribution diagram of heat exchange tubes in a cross section of a pulverized coal preheating device.

FIG. 3 is a second distribution pattern of heat exchange tubes in cross-section of a pulverized coal preheating apparatus, wherein the heat exchange tubes are uniformly distributed with circumferential thickness.

Fig. 4 is a perspective view of the structure of the heat exchange assembly.

Fig. 5 is a side view of a 60 ton preheater tube bundle according to the example.

In the figure, 1 is a flue gas inlet, 2 is a flue gas outlet, 3 is a spiral flow deflector, 4 is a heat exchange tube, 5 is a spiral fin, 6 is a sleeve, 7 is a hollow supporting tube, and 8 is a distance tube.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail with reference to the embodiments and the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. The technical solution of the present invention is described in detail below with reference to the embodiments and the drawings, but the scope of protection is not limited thereto.

As shown in fig. 1, this embodiment is a high-efficient pulverized coal preheating device, and this pulverized coal preheating device is a tubular structure, be provided with inlet for flue gas 1 and exhanst gas outlet 2 on the tubular structure pipe wall, the inner wall of tubular structure is along axial fixedly connected with heliciform water conservancy diversion piece 3 and a plurality of heat exchange assembly, and a plurality of heat exchange assembly use the outside multilayer circumference evenly distributed of center pin of tubular structure or along the thick rule distribution of circumference (as shown in fig. 2 and fig. 3). The inner heat exchange assembly penetrates through the spiral flow deflector 3 along the axial direction of the tubular structure.

A hollow supporting tube 7 is axially arranged at the center of the tubular structure; the spiral flow deflector 3 is arranged around the hollow supporting tube 7 and is fixedly connected with the hollow supporting tube 7. The two ends of the hollow supporting tube 7 are of closed structures. A distance pipe 8 is connected between two adjacent spiral sheets of the spiral flow deflector 3. Because the middle part has set up the stay tube, the structure of heliciform water conservancy diversion piece 3 is more firm, and high temperature flue gas distributes more evenly in the spiral flue, and heat conduction efficiency improves simultaneously, and the flue gas flow resistance reduces, has improved the operating efficiency of whole buggy preheating process, and energy-conserving effect is more obvious. And a distance tube 8 connected between two adjacent spiral sheets ensures the stability of the spiral sheets.

As shown in fig. 4, the heat exchange assembly comprises a heat exchange tube 4 and a spiral fin 5 made of metal, the spiral fin 5 is arranged and welded on the outer wall of the heat exchange tube 4 along the axial direction of the heat exchange tube 4, a sleeve 6 is sleeved outside the spiral fin 5, the heat exchange tube 4 is communicated with the spiral fin 5 and can axially slide in the sleeve 6, the sleeve 6 only needs to be arranged at the joint of the spiral fin 5 and the spiral flow deflector 3, and the sleeve 6 is fixedly connected with the spiral flow deflector 3. In the process of coal dust heat exchange and air flow heat exchange together, the heat exchange tube 4, the spiral fins 5 and the spiral flow deflector 3 can expand with heat and contract with cold, and the coefficients of expansion with heat and contraction with cold are different; and sleeve 6 between heliciform water conservancy diversion piece 3 and helical fin 5 prevents effectively that the collision and the hook each other that produce in expend with heat and contract with cold in-process, and heat exchange tube 4 can be relative 3 self-adaptation of heliciform water conservancy diversion pieces to adjust, effectively enlarges heat transfer area of contact when flue gas air current heat transfer is more even, has improved heat exchange efficiency.

As shown in fig. 5, the tubular structure in this embodiment is formed by combining three sections of tubular shells, and is used for a 60 ton preheater tube bundle, and each section of tubular shell is formed by fastening an upper shell and a lower shell which are axially arranged. When the pipe is installed, the upper half part is covered and connected after the lower half part three-section pipe and the internal components are installed. The outer wall of the tubular structure is wrapped with a heat insulating material.

Because the heat exchange device adopts the spiral flow deflector, the high-temperature flue gas and the coal heating pipe fully and uniformly exchange heat in the preheating device, no air flow dead angle exists, the heat exchange efficiency is improved, and the pulverized coal can be rapidly heated to the critical ignition point of the pulverized coal from about 40 ℃ to about 350 ℃ within 3 seconds. Compared with the prior art, the heat exchanger has the advantages that the volume is reduced, the strength is improved, and due to the adoption of the round tubular structure, the heat insulation material on the outer wall is convenient to install, and the fixing effect is good. Because the supporting pipe is arranged in the middle of the coal dust preheating device, the spiral flow deflector is firmer in structure, high-temperature flue gas is more uniformly distributed in the spiral flue, the heat conduction efficiency is improved, the flow resistance of the flue gas is reduced, the operation efficiency of the whole coal dust preheating process is improved, and the energy-saving effect is more obvious.

While the invention has been described in further detail with reference to specific preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.