Grain dryer heat exchanger with flue gas turbulent flow structure

Abstract

The invention discloses a heat exchanger with a smoke turbulence structure for a grain dryer, which comprises a combustion chamber, a smoke collecting ring and a smoke shunting mechanism, the smoke shunting mechanism comprises a cylindrical smoke collecting chamber, a plurality of heat exchange tubes arranged around the combustion chamber are connected between the smoke collecting ring and the smoke collecting chamber, and the smoke collecting ring is connected with a chimney; a cylinder part coaxial with the smoke collecting chamber is mounted in the smoke collecting chamber; a gap is formed between the rear end of the cylinder part and the inner wall of the rear side of the smoke collecting chamber; at least two partition plates are arranged in an annular gap between the inner wall of the smoke collecting chamber and the outer wall of the cylinder part; one of two adjacent partition plates is provided with a plurality of first through holes distributed close to the outer edge of the partition plate, and the other partition plate is provided with a plurality of second through holes distributed close to the inner edge of the partition plate. According to the invention, flue gas enters the annular gap from the rear end of the cylinder part, is turned once, and is subjected to a turbulent flow effect through the through hole groups in different partition plates, so that the flow rate of the flue gas can be slowed down, and the heat of the flue gas can be fully dissipated.

Description

Technical Field

[0001] The present invention relates to the technical field of grain drying, in particular to a heat exchanger for a grain dryer with a smoke turbulence structure. Background Art

[0002] Fresh grain generally has a high moisture content after harvest, requiring prompt and thorough drying to ensure safe storage and prevent moisture-induced mold or rot. Untimely or improper drying results in over 5% of grain loss annually. In June, some major grain-producing areas may experience "rotten field rain" weather, further exacerbating grain losses. Faced with complex emergency drying conditions and the high moisture content of wet grain, existing grain drying equipment suffers from low heat exchange efficiency, lacks mobility, and slow drying rates, making it difficult to effectively address the 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 generally cylindrical. An exhaust gas collection chamber is arranged around the heat outlet of the combustion chamber, and the outer periphery of the exhaust gas collection chamber is wrapped by the exhaust gas collection chamber shell. An exhaust port is provided 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 guide heat exchange device. These heat exchange tubes are provided with an outlet at one end and an inlet at the other end. The outlet of the heat exchange tube is connected to the exhaust gas collection chamber, and the inlet of the heat exchange tube is connected to a heat energy distribution chamber. The heat energy distribution chamber is located at the rear end of the combustion chamber and is equipped with a heat energy distribution plate. In actual use, the solution of this patent fails to dissipate the heat carried by the flue gas in a timely manner due to the excessively rapid flow of the flue gas generated by combustion. The flue gas still has a high temperature when it is discharged, resulting in heat energy waste. Summary of the Invention

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

[0005] Technical solution: To achieve the above-mentioned purpose, the heat exchanger for a grain dryer with a smoke turbulence structure of the present invention includes a combustion chamber, a connection mechanism for connecting to a burner is provided at the front end of the combustion chamber, a smoke collecting ring and a smoke diversion mechanism are respectively installed at the front and rear ends of the combustion chamber, the smoke diversion mechanism includes a cylindrical smoke collecting chamber, a plurality of heat exchange tubes arranged around the combustion chamber are connected between the smoke collecting ring and the smoke collecting chamber, and the smoke collecting ring is connected to the chimney;

[0006] During operation, the burner at the front of the combustion chamber injects fuel and air into the combustion chamber, causing the two to mix and burn. The resulting flue gas passes through the flue gas diversion mechanism and enters the heat exchange tubes. Ultimately, all the flue gas converges into the smoke collection ring and is discharged through the chimney. The airflow used to dry the grain passes through the outside of the heat exchanger, absorbing heat from the heat exchange tubes and the outer wall of the combustion chamber, and then becomes hot air to dry the grain.

[0007] A cylindrical portion coaxially arranged therewith is installed in the smoke collecting chamber; the rear end of the cylindrical portion is open, and a gap is formed between the rear end and the rear inner wall of the smoke collecting chamber;

[0008] At least two partitions are disposed within the annular gap between the inner wall of the smoke collection chamber and the outer wall of the cylindrical portion. One of the two adjacent partitions 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 the heat exchange tubes. All the first through-holes are referred to as a first through-hole group, and all the second through-holes are referred to as a second through-hole group.

[0009] After the smoke enters the smoke 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 partitions in the annular gap are staggered with each other, it can effectively form a turbulent effect on the smoke.

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

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

[0012] When in use, an air flow heat exchange chamber is set around the outside of the heat exchanger. The front side of the air flow heat exchange chamber is connected to the blower. The blower blows the air flow into the front half of the air flow heat exchange chamber, that is, the side close to the smoke collecting ring. The blowing direction of the blower is perpendicular to the axial direction of the combustion chamber. The air flow enters the front half of the air flow heat exchange chamber perpendicular to the axial direction of the combustion chamber, and then turns and enters the back half of the air flow heat exchange chamber. Since the heat dissipation ribs are distributed in the back half of the outer wall of the combustion chamber and extend from the gaps between the heat exchange tubes, the air flow entering the back half of the air flow heat exchange chamber can flow along the heat exchange tubes, fully absorbing the heat from the heat dissipation ribs and the heat exchange tubes, thereby improving the heat exchange efficiency.

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

[0014] By adjusting the position, the cylindrical part can have three positions relative to the combustion chamber and the smoke collection chamber:

[0015] The first type is that the cylindrical part is located at the front end of the smoke collection chamber and is directly connected to the rear end of the combustion chamber. At this time, all the flue gas must pass through the gap between the rear end of the cylindrical part and the rear inner wall of the smoke collection chamber to enter the annular gap, and then enter the heat exchange tube after turbulence. At this time, the flow rate of the flue gas is the slowest.

[0016] The second type is that the cylindrical part is located in the middle section of the smoke collection chamber, and there is a gap between the front end of the cylindrical part and the rear end of the combustion chamber, and there is also a gap between the rear end of the cylindrical part and the rear end inner wall of the smoke collection chamber. At this time, the cylindrical part can play a diversion role. A part of the flue gas coming out of the combustion chamber directly enters each heat exchange tube from the gap at the front end of the cylindrical part, and the other part of the flue gas enters each heat exchange tube from the gap at the rear end of the cylindrical part and the annular gap. By changing the position of the cylindrical part, the diversion ratio can be accurately adjusted to achieve precise adjustment of the flue gas flow rate.

[0017] The third type is that the cylindrical part is located at the rear end of the smoke collecting chamber, and the rear end of the cylindrical part is against the rear end inner wall of the smoke collecting chamber. At this time, all the smoke enters each heat exchange tube directly from the front end gap of the cylindrical part, and the smoke flow speed is the fastest.

[0018] In this way, the flue gas flow rate can be precisely adjusted as needed to ensure 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 provided with a power access wheel, and all the power access wheels establish a power transmission relationship with the same transmission wheel. Here, the power access wheel and the transmission wheel can both 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 the present 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 groups on different partitions. 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, thereby improving the heat exchange rate.

[0022] (2) The spiral guide vane can make the flue gas move along a spiral path in the heat exchange tube, thereby increasing the length of the flue gas movement path, slowing down the flue gas again, extending the heat exchange time, and further improving the heat exchange efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0024] Figure 2This is a cross-sectional structural diagram of a heat exchanger for a grain dryer with a flue gas turbulence structure;

[0025] Figure 3 This is a sectional perspective structural diagram of a heat exchanger for a grain dryer with a flue gas turbulence structure;

[0026] Figure 4 for Figure 3 A magnified structural diagram of part A;

[0027] Figure 5 A schematic diagram of the flue gas flow path of the flue gas diversion mechanism in one state;

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

[0029] Figure 7 It is a cross-sectional structural diagram of the heat exchanger in a preferred embodiment.

[0030] In the figure: 1-combustion chamber; 11-heat dissipation rib; 2-smoke collecting ring; 3-smoke diversion mechanism; 31-smoke collecting chamber; 32-cylindrical portion; 33-partition; 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 DESCRIPTION

[0031] The present invention will be further described below 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 in the figure comprises a combustion chamber 1, the front end of the combustion chamber 1 having a connection mechanism for connecting to a burner, the front and rear ends of the combustion chamber 1 being respectively equipped with a smoke collecting ring 2 and a smoke diversion mechanism 3, the smoke diversion mechanism 3 comprising a cylindrical smoke collecting chamber 31, a plurality of heat exchange tubes 4 arranged around the combustion chamber 1 being connected between the smoke collecting ring 2 and the smoke collecting chamber 31, and the smoke collecting ring 2 being connected to a chimney 5;

[0033] During operation, the burner at the front end of the combustion chamber 1 injects fuel and air into the combustion chamber 1 for mixed combustion. The smoke generated by the combustion passes through the smoke diversion mechanism 3 and enters the heat exchange tubes 4. Finally, all the smoke converges into the smoke collecting ring 2 and is discharged through the chimney 5. The airflow used to dry 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 a hot airflow to dry the grain.

[0034] A cylindrical portion 32 is installed in the smoke collecting chamber 31 and arranged coaxially therewith; the rear end of the cylindrical portion 32 is open, and there is a gap between the rear end and the rear inner wall of the smoke collecting chamber 31;

[0035] At least two partitions 33 are provided in the annular gap between the inner wall of the smoke collecting chamber 31 and the outer wall of the cylindrical portion 32; Figure 4 As shown, one of the two adjacent partitions 33 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 a first through hole group, and all the second through holes 33b are referred to as a second through hole group.

[0036] After the smoke enters the smoke diversion mechanism 3, it passes through the cylindrical portion 32 to the rear end of the cylindrical portion 32, and then enters the annular gap through the gap between the rear end of the cylindrical portion 32 and the rear inner wall of the smoke collecting chamber 31. Since the first through hole group and the second through hole group on the adjacent partitions 33 in the annular gap are staggered with each other, an effective turbulence effect can be formed on the smoke.

[0037] In the present 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 portion 32, passes through a turn, and is subjected to turbulence through the through-hole groups on different partitions 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, thereby improving the heat exchange rate.

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

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

[0040] Preferably, if 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 of the heat dissipation ribs 11 extends outward from the gap between two adjacent heat exchange tubes 4.

[0041] When in use, an air flow heat exchange chamber is set around the outside of the heat exchanger, and the front side of the air flow heat exchange chamber is connected to the blower. The blower blows the air flow into the front half of the air flow heat exchange chamber, that is, the side close to the smoke collecting ring 2. The blowing direction of the blower is perpendicular to the axial direction of the combustion chamber 1. The air flow enters the front half of the air flow heat exchange chamber perpendicular to the axial direction of the combustion chamber 1, and then turns and enters the back half of the air flow heat exchange chamber. Since the heat dissipation ribs 11 are distributed in the back half of the outer wall of the combustion chamber 1 and extend from the gaps between the heat exchange tubes 4, the air flow entering the back half of the air flow heat exchange chamber can flow along each heat exchange tube 4, fully absorbing the heat from the heat dissipation ribs 11 and the heat exchange tube 4, thereby improving the heat exchange efficiency.

[0042] Preferably, the cylindrical portion 32 can be axially adjusted relative to the smoke collecting chamber 31 .

[0043] By adjusting the position, the cylindrical portion 32 can have three position states relative to the combustion chamber 1 and the smoke collecting chamber 31:

[0044] The first one, such as Figure 5 As shown, the cylindrical portion 32 is located at the front end of the smoke collecting chamber 31, and the cylindrical portion 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 portion 32 and the rear inner wall of the smoke collecting chamber 31 to enter the annular gap, and then enter the heat exchange tube 4 after the turbulence. 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 portion 32 is located in the middle section of the smoke collecting chamber 31. There is a gap between the front end of the cylindrical portion 32 and the rear end of the combustion chamber 1, and there is also a gap between the rear end of the cylindrical portion 32 and the rear end inner wall of the smoke collecting chamber 31. At this time, the cylindrical portion 32 can play a diversion role. A part of the flue gas coming out of the combustion chamber 1 directly enters each heat exchange tube 4 from the gap at the front end of the cylindrical portion 32, and the other part of the flue gas enters each heat exchange tube 4 from the gap at the rear end of the cylindrical portion 32 and the annular gap. By changing the position of the cylindrical portion 32, the diversion ratio can be accurately adjusted to achieve precise adjustment of the flue gas flow rate.

[0046] The third type is that the cylindrical portion 32 is located at the rear end of the smoke collecting chamber 31, and the rear end of the cylindrical portion 32 is against the rear end inner wall of the smoke collecting chamber 31. At this time, all the smoke directly enters each heat exchange tube 4 from the front end gap of the cylindrical portion 32, and the smoke flow speed is the fastest.

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

[0048] Preferably, if Figure 7 As shown, all of the heat exchange tubes 4 are capable of rotating relative to the combustion chamber 1, and each heat exchange tube 4 is provided with a power input wheel 6, all of which establish a power transmission relationship with 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 tubes 4 include spiral guide vanes 41, rotating the heat exchange tubes 4 also causes the spiral guide vanes 41 to rotate. The forward and reverse rotation of the spiral guide vanes 41 can achieve both propulsion and obstruction effects on the flue gas, further hindering or accelerating the flow of the flue gas.

[0049] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as 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), wherein the front end of the combustion chamber (1) is provided with a connection mechanism for connecting to a burner, a smoke collecting ring (2) and a smoke diversion mechanism (3) are respectively installed at the front and rear ends of the combustion chamber (1), the smoke diversion mechanism (3) comprising a cylindrical smoke collecting chamber (31), a plurality of heat exchange tubes (4) arranged around the combustion chamber (1) are connected between the smoke collecting ring (2) and the smoke collecting chamber (31), and the smoke collecting ring (2) is connected to a chimney (5); Its characteristics are: A cylindrical portion (32) arranged coaxially with the smoke collecting chamber (31) is installed in the smoke collecting chamber (31); the rear end of the cylindrical portion (32) is open, and a gap is formed between the rear end and the rear inner wall of the smoke collecting chamber (31); At least two partitions (33) are provided in the annular gap between the inner wall of the smoke collecting chamber (31) and the outer wall of the cylindrical portion (32); one of the two adjacent partitions (33) 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.

2. The heat exchanger for a grain dryer with a flue gas turbulence structure according to claim 1, characterized in that: A spiral guide plate (41) is installed in each heat exchange tube (4).

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 heat dissipation ribs (11) extending outwards, the heat dissipation ribs (11) are parallel to the axial direction of the combustion chamber (1), and each heat dissipation rib (11) extends outwards 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: The cylindrical portion (32) can be axially adjusted relative to the smoke collecting chamber (31).

5. 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 capable of rotating 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) establish a power transmission relationship with the same transmission wheel (7).

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