A heat exchanger with flue gas spoiler structure for grain dryer

Abstract

This invention discloses a heat exchanger for a grain dryer with a flue gas turbulence structure, comprising a combustion chamber, a flue gas collecting ring, and a flue gas diversion mechanism. The flue gas diversion mechanism includes a cylindrical flue gas collecting chamber, with multiple heat exchange tubes arranged around the combustion chamber connected to the flue gas collecting ring, and the flue gas collecting ring connected to a chimney. A cylindrical section coaxially arranged within the flue gas collecting chamber is installed therein. The rear end of the cylindrical section is open, and there is a gap between the rear end and the rear inner wall of the flue gas collecting chamber. At least two baffles are arranged within the annular gap between the inner wall of the flue gas collecting chamber and the outer wall of the cylindrical section. In two adjacent baffles, one has multiple first through holes distributed near its outer edge, and the other has multiple second through holes distributed near its inner edge. In this invention, the flue gas enters the annular gap from the rear end of the cylindrical section, undergoes a turn, and is further turbulent by the through holes on the different baffles. This slows down the flow rate of the flue gas, allowing the heat of the flue gas to be fully dissipated.

Description

Technical Field

[0001] This invention relates to the field of grain drying technology, and in particular to a heat exchanger for a grain dryer with a flue gas turbulence structure. Background Technology

[0002] Fresh grains generally have a high moisture content after harvest and must be dried thoroughly and promptly to meet the requirements for safe storage and prevent mold or rot caused by dampness. Due to untimely drying or improper handling, the annual grain loss rate exceeds 5%. Particularly in June, some major grain-producing areas may experience "dammed fields" (rain that spoils the grain), further exacerbating losses. Faced with complex emergency drying environments and high-moisture grains, existing grain drying equipment generally suffers from low heat exchange efficiency, lack of mobility, and slow moisture reduction, making it difficult to effectively meet the practical needs of disaster prevention, emergency response, and rapid loss reduction.

[0003] In the prior art, patent CN 105928355 A discloses a heat exchange mechanism in which the combustion chamber is cylindrical, and an exhaust gas collection chamber is arranged around the heat outlet of the combustion chamber, which is surrounded by an exhaust gas collection chamber shell. An exhaust port is located at the top of the exhaust gas collection chamber. Multiple heat exchange tubes are arranged circumferentially around the outer wall of the combustion chamber. Each heat exchange tube is equipped with a four-plate spiral flow guiding heat exchange device. One end of these heat exchange tubes has an exhaust port, and the other end has an inlet. The exhaust port of the heat exchange tube is connected to the exhaust gas collection chamber; the inlet of the heat exchange tube is connected to a heat energy equalization chamber. This heat energy equalization chamber is located at the rear end of the combustion chamber and contains heat energy equalization plates. In practical use, the flue gas generated by combustion flows too quickly, causing the heat carried by the flue gas to not be exchanged in time, resulting in the flue gas still having a high temperature when discharged, thus wasting heat energy. Summary of the Invention

[0004] Purpose of the invention: In order to overcome the shortcomings of the prior art, the present invention provides a heat exchanger for a grain dryer with a flue gas turbulence structure that can reduce the flue gas flow rate so that the heat of the flue gas can be fully dissipated.

[0005] Technical solution: To achieve the above objectives, the present invention provides a heat exchanger for a grain dryer with a flue gas turbulence structure, which includes a combustion chamber. The front end of the combustion chamber has a connecting mechanism for connecting to a burner. The front and rear ends of the combustion chamber are respectively equipped with a smoke collection ring and a flue gas diversion mechanism. The flue gas diversion mechanism includes a cylindrical smoke collection chamber. The smoke collection ring and the smoke collection chamber are connected by a plurality of heat exchange tubes arranged around the combustion chamber, and the smoke collection ring is connected to a chimney.

[0006] During operation, the burner located at the front of the combustion chamber injects fuel and air into the combustion chamber for mixing and combustion. The resulting flue gas passes through the flue gas diversion mechanism and then enters each heat exchange tube. Finally, all the flue gas converges into the smoke collection ring and is discharged from the chimney. The airflow used for drying the grain passes through the outside of the heat exchanger, absorbs heat from the heat exchange tubes and the outer wall of the combustion chamber, and becomes hot airflow to dry the grain.

[0007] A cylindrical part is installed in the smoke collection chamber and is arranged coaxially with it; the rear end of the cylindrical part is open and there is a gap between the rear end and the rear inner wall of the smoke collection chamber.

[0008] At least two baffles are provided in the annular gap between the inner wall of the smoke collection chamber and the outer wall of the cylindrical part; one of the two adjacent baffles has a plurality of first through holes distributed near its outer edge, and the other has a plurality of second through holes distributed near its inner edge. The front side of the annular gap is connected to each heat exchange tube. All the first through holes are referred to as the first through hole group, and all the second through holes are referred to as the second through hole group.

[0009] After the flue gas enters the flue gas diversion mechanism, it passes through the cylindrical part to the rear end of the cylindrical part, and then enters the annular gap through the gap between the rear end of the cylindrical part and the rear inner wall of the smoke collection chamber. Since the first through hole group and the second through hole group on the adjacent partition plate in the annular gap are staggered, they can effectively create a turbulence effect on the flue gas.

[0010] Furthermore, each of the heat exchange tubes is equipped with a spiral guide vane.

[0011] Furthermore, the rear half of the outer wall of the combustion chamber has outwardly extending heat dissipation ribs, which are parallel to the axial direction of the combustion chamber, and each heat dissipation rib extends outward from the gap between two adjacent heat exchange tubes.

[0012] In use, an airflow heat exchange chamber is arranged around the outside of the heat exchanger. A blower is connected to the front of the airflow heat exchange chamber. The blower blows air into the front half of the airflow heat exchange chamber, that is, the side close to the smoke collection ring. The blower's blowing direction is perpendicular to the axial direction of the combustion chamber. The airflow enters the front half of the airflow heat exchange chamber perpendicular to the axial direction of the combustion chamber, and then turns and enters the rear half of the airflow heat exchange chamber. Since the heat dissipation fins are distributed on the rear half of the outer wall of the combustion chamber and extend out from the gaps between the heat exchange tubes, the airflow entering the rear half of the airflow heat exchange chamber can flow along each heat exchange tube, fully absorbing the heat from the heat dissipation fins and heat exchange tubes, thus improving the heat exchange efficiency.

[0013] Furthermore, the cylindrical portion can be axially adjusted relative to the smoke collection chamber.

[0014] By adjusting its position, the cylindrical section can have three positional states relative to the combustion chamber and the smoke collection chamber:

[0015] In the first type, the cylindrical section is located at the front end of the smoke collection chamber and is directly connected to the rear end of the combustion chamber. In this case, all the flue gas must pass through the gap between the rear end of the cylindrical section and the rear inner wall of the smoke collection chamber to enter the annular gap, and after being turbulent, it enters the heat exchange tube. At this time, the flow rate of the flue gas is the slowest.

[0016] The second type has a cylindrical section located in the middle of the smoke collection chamber. There is a gap between the front end of the cylindrical section and the rear end of the combustion chamber, and there is also a gap between the rear end of the cylindrical section and the inner wall of the rear end of the smoke collection chamber. In this case, the cylindrical section can play a role in diverting the flow. Part of the flue gas coming out of the combustion chamber enters each heat exchange tube directly through the gap at the front end of the cylindrical section, while the other part of the flue gas enters each heat exchange tube through the gap at the rear end of the cylindrical section and the annular gap. By changing the position of the cylindrical section, the flow diversion ratio can be precisely adjusted, thereby achieving precise adjustment of the flue gas velocity.

[0017] The third type has a cylindrical section located at the rear end of the smoke collection chamber, with the rear end of the cylindrical section abutting against the inner wall of the rear end of the smoke collection chamber. In this case, all the flue gas directly enters each heat exchange tube from the front end gap of the cylindrical section, resulting in the fastest flue gas flow rate.

[0018] In this way, the flue gas flow rate can be precisely adjusted as needed, ensuring sufficient heat exchange while improving heat exchange efficiency.

[0019] Furthermore, all the heat exchange tubes are rotatable relative to the combustion chamber, and each heat exchange tube is equipped with a power input wheel, all of which establish a power transmission relationship with the same transmission wheel. Here, both the power input wheel and the transmission wheel can be gears or friction wheels.

[0020] Beneficial effects: The heat exchanger for a grain dryer with a flue gas turbulence structure of the present invention has the following beneficial effects:

[0021] (1) In this invention, by designing the internal structure of the flue gas diversion mechanism, the flow path of the flue gas from the combustion chamber to the heat exchange tube can be changed. The flue gas enters the annular gap from the rear end of the cylindrical part and undergoes a turn. It is then subjected to turbulence through the through-hole group on different baffles. In this way, the flow rate of the flue gas can be slowed down, so that the heat of the flue gas can be fully dissipated and the heat exchange rate can be improved.

[0022] (2) The spiral guide vanes allow the flue gas to move along a spiral path in the heat exchange tube, which increases the length of the flue gas movement path, slows down the flue gas again, prolongs the heat exchange time, and further improves the heat exchange efficiency. Attached Figure Description

[0023] Figure 1 This is a structural diagram of a heat exchanger for a grain dryer with a flue gas turbulence structure.

[0024] Figure 2A cross-sectional view of a heat exchanger for a grain dryer with a flue gas turbulence structure.

[0025] Figure 3 A cross-sectional three-dimensional structural diagram of a heat exchanger for a grain dryer with a flue gas turbulence structure;

[0026] Figure 4 for Figure 3 Enlarged structural diagram of section A;

[0027] Figure 5 This is a schematic diagram of the flue gas flow path of a flue gas diversion mechanism under one condition.

[0028] Figure 6 This is a schematic diagram of the flue gas flow path of the flue gas diversion mechanism in the second state;

[0029] Figure 7 This is a cross-sectional view of the heat exchanger in a preferred embodiment.

[0030] In the diagram: 1-combustion chamber; 11-heat dissipation fins; 2-smoke collection ring; 3-smoke diversion mechanism; 31-smoke collection chamber; 32-cylindrical section; 33-baffle plate; 33a-first through hole; 33b-second through hole; 4-heat exchange tube; 41-spiral guide vane; 5-chimney; 6-power input wheel; 7-transmission wheel. Detailed Implementation

[0031] The invention will now be further described with reference to the accompanying drawings.

[0032] like Figures 1 to 3 The heat exchanger for a grain dryer with a flue gas turbulence structure shown includes a combustion chamber 1. The front end of the combustion chamber 1 has a connecting mechanism for connecting to the burner. The front and rear ends of the combustion chamber 1 are respectively equipped with a smoke collection ring 2 and a flue gas diversion mechanism 3. The flue gas diversion mechanism 3 includes a cylindrical smoke collection chamber 31. The smoke collection ring 2 and the smoke collection chamber 31 are connected by a plurality of heat exchange tubes 4 arranged around the combustion chamber 1, and the smoke collection ring 2 is connected to a chimney 5.

[0033] During operation, the burner located at the front end of the combustion chamber 1 injects fuel and air into the combustion chamber 1 for mixing and combustion. The flue gas produced by combustion passes through the flue gas diversion mechanism 3 and enters each heat exchange tube 4. Finally, all the flue gas converges into the smoke collection ring 2 and is discharged from the chimney 5. The airflow used for drying the grain passes through the outside of the heat exchanger, absorbs heat from the heat exchange tubes 4 and the outer wall of the combustion chamber 1, and becomes hot airflow to dry the grain.

[0034] The smoke collection chamber 31 is equipped with a cylindrical part 32 arranged coaxially with it; the rear end of the cylindrical part 32 is open, and there is a gap between the rear end and the rear inner wall of the smoke collection chamber 31.

[0035] At least two partitions 33 are provided in the annular gap between the inner wall of the smoke collection chamber 31 and the outer wall of the cylindrical part 32; for example Figure 4 As shown, in two adjacent partitions 33, one has a plurality of first through holes 33a distributed near its outer edge, and the other has a plurality of second through holes 33b distributed near its inner edge. The front side of the annular gap is connected to each heat exchange tube 4. All the first through holes 33a are referred to as the first through hole group, and all the second through holes 33b are referred to as the second through hole group.

[0036] After the flue gas enters the flue gas diversion mechanism 3, it passes through the cylindrical part 32 to the rear end of the cylindrical part 32, and then enters the annular gap through the gap between the rear end of the cylindrical part 32 and the rear inner wall of the smoke collection chamber 31. Since the first through hole group and the second through hole group on the adjacent partition 33 in the annular gap are staggered, they can effectively create a turbulence effect on the flue gas.

[0037] In this invention, by designing the internal structure of the flue gas diversion mechanism 3, the flow path of the flue gas from the combustion chamber 1 to the heat exchange tube 4 can be changed. The flue gas enters the annular gap from the rear end of the cylindrical part 32, undergoes a turn, and is turbulent again through the through-hole group on different baffles 33. In this way, the flow rate of the flue gas can be slowed down, so that the heat of the flue gas can be fully dissipated and the heat exchange rate can be improved.

[0038] Preferably, each of the heat exchange tubes 4 is equipped with a spiral guide vane 41.

[0039] The spiral guide vane 41 allows the flue gas to move along a spiral path inside the heat exchange tube 4, increasing the length of the flue gas's movement path, further slowing down the flue gas, extending the heat exchange time, and further improving the heat exchange efficiency.

[0040] Preferably, such as Figure 7 As shown, the rear half of the outer wall of the combustion chamber 1 has outwardly extending heat dissipation ribs 11, which are parallel to the axial direction of the combustion chamber 1, and each heat dissipation rib 11 extends outward from the gap between two adjacent heat exchange tubes 4.

[0041] In use, an airflow heat exchange chamber is arranged around the outside of the heat exchanger. A blower is connected to the front of the airflow heat exchange chamber. The blower blows airflow into the front half of the airflow heat exchange chamber, that is, the side close to the smoke collection ring 2. The blower's blowing direction is perpendicular to the axis of the combustion chamber 1. The airflow enters the front half of the airflow heat exchange chamber in a direction perpendicular to the axis of the combustion chamber 1, and then turns and enters the rear half of the airflow heat exchange chamber. Since the heat dissipation fins 11 are distributed on the rear half of the outer wall of the combustion chamber 1 and extend out from the gaps between the heat exchange tubes 4, the airflow entering the rear half of the airflow heat exchange chamber can flow along each heat exchange tube 4, fully absorbing the heat from the heat dissipation fins 11 and the heat exchange tubes 4, thus improving the heat exchange efficiency.

[0042] Preferably, the cylindrical portion 32 is axially adjustable relative to the smoke collection chamber 31.

[0043] By adjusting its position, the cylindrical section 32 can have three positional states relative to the combustion chamber 1 and the smoke collection chamber 31:

[0044] The first type, such as Figure 5 As shown, the cylindrical part 32 is located at the front end of the smoke collection chamber 31. The cylindrical part 32 is directly connected to the rear end of the combustion chamber 1. At this time, all the flue gas must pass through the gap between the rear end of the cylindrical part 32 and the rear inner wall of the smoke collection chamber 31 to enter the annular gap. After being turbulent, it enters the heat exchange tube 4. At this time, the flow rate of the flue gas is the slowest.

[0045] The second type, such as Figure 6 As shown, the cylindrical section 32 is located in the middle section of the smoke collection chamber 31. There is a gap between the front end of the cylindrical section 32 and the rear end of the combustion chamber 1, and there is also a gap between the rear end of the cylindrical section 32 and the inner wall of the rear end of the smoke collection chamber 31. At this time, the cylindrical section 32 can play a role in diverting the flow. Part of the flue gas coming out of the combustion chamber 1 directly enters each heat exchange tube 4 through the gap at the front end of the cylindrical section 32, and the other part of the flue gas enters each heat exchange tube 4 through the gap at the rear end of the cylindrical section 32 and the annular gap. By changing the position of the cylindrical section 32, the diversion ratio can be precisely adjusted, and the flue gas velocity can be precisely adjusted.

[0046] The third type has a cylindrical section 32 located at the rear end of the smoke collection chamber 31, with the rear end of the cylindrical section 32 abutting against the inner wall of the rear end of the smoke collection chamber 31. In this case, all the flue gas directly enters each heat exchange tube 4 from the front end gap of the cylindrical section 32, and the flue gas flow speed is the fastest.

[0047] In this way, the flue gas flow rate can be precisely adjusted as needed, ensuring sufficient heat exchange while improving heat exchange efficiency.

[0048] Preferably, such as Figure 7 As shown, all the heat exchange tubes 4 are rotatable relative to the combustion chamber 1, and each heat exchange tube 4 is equipped with a power input wheel 6. All power input wheels 6 are connected to the same transmission wheel 7. Here, the power input wheel 6 and the transmission wheel 7 can both be gears or friction wheels. Since the heat exchange tube 4 has a spiral guide vane 41, rotating the heat exchange tube 4 can cause the spiral guide vane 41 to rotate. The forward and reverse rotation of the spiral guide vane 41 can achieve the function of promoting and hindering the flue gas, which can further hinder or accelerate the flow of the flue gas.

[0049] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A heat exchanger for a grain dryer with a flue gas turbulence structure, comprising a combustion chamber (1), the front end of the combustion chamber (1) having a connecting mechanism for connecting a burner, a smoke collection ring (2) and a flue gas diversion mechanism (3) respectively installed at the front and rear ends of the combustion chamber (1), the flue gas diversion mechanism (3) including a cylindrical smoke collection chamber (31), a plurality of heat exchange tubes (4) arranged around the combustion chamber (1) being connected between the smoke collection ring (2) and the smoke collection chamber (31), and the smoke collection ring (2) being connected to a chimney (5); characterized in that The smoke collection chamber (31) is equipped with a cylindrical part (32) arranged coaxially with it; the rear end of the cylindrical part (32) is open, and there is a gap between the rear end and the rear inner wall of the smoke collection chamber (31); At least two partitions (33) are provided in the annular gap between the inner wall of the smoke collection chamber (31) and the outer wall of the cylindrical part (32); among the two adjacent partitions (33), one has a plurality of first through holes (33a) distributed near its outer edge, and the other has a plurality of second through holes (33b) distributed near its inner edge. The cylindrical portion (32) can be axially adjusted relative to the smoke collection chamber (31).

2. The heat exchanger for a grain dryer with a flue gas turbulence structure according to claim 1, characterized in that, Each of the heat exchange tubes (4) is equipped with a spiral guide vane (41).

3. The heat exchanger for a grain dryer with a flue gas turbulence structure according to claim 1, characterized in that, The rear half of the outer wall of the combustion chamber (1) has outwardly extending heat dissipation ribs (11), which are parallel to the axial direction of the combustion chamber (1) and each heat dissipation rib (11) extends outward from the gap between two adjacent heat exchange tubes (4).

4. The heat exchanger for a grain dryer with a flue gas turbulence structure according to claim 1, characterized in that, All the heat exchange tubes (4) are rotatable relative to the combustion chamber (1), and each heat exchange tube (4) is provided with a power access wheel (6), and all the power access wheels (6) are connected to the same transmission wheel (7) for power transmission.

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