Rotary air pre-heater

Abstract

The utility model provides a rotary air pre-heater, and relates to the field of air pre-heaters. The rotary air pre-heater comprises an air pre-heater body, the air pre-heater body comprises a rotor outer cover, a primary air inlet, a primary air outlet, a secondary air inlet, a secondary air outlet, a flue gas inlet and a flue gas outlet, and rotating rods are rotationally installed on the primary air outlet, the secondary air outlet and the flue gas inlet; according to the rotary air pre-heater, the transmission mode that the worm drives the worm gear to rotate is adopted, the primary air baffle, the secondary air baffle and the smoke opening baffle are slowly closed, after the primary air baffle is closed to 70%, adjustment is conducted in a hand-cranking mode, the primary air supply and combustion requirements are better balanced, the combustion stability is guaranteed, and the service life of the air pre-heater is prolonged. The self-locking property of worm transmission cannot be accidentally and rapidly closed or opened due to external force interference such as smoke pressure and vibration in the closing process, stable closing is conducted all the time according to the set speed, the risk that closing is out of control due to external factors is reduced, and stable operation of a combustion and ventilation system is maintained.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of air preheater, concretely to a rotary air preheater. BACKGROUND

[0002] Air preheater refers to air preheater, it is a kind of heat exchange equipment for improving the thermal efficiency of boiler, its main function is to utilize the flue gas waste heat in the tail flue of boiler to heat the air required for combustion (primary air is used to transport and dry pulverized coal, and secondary air is used for combustion support), and the rotary air preheater is a common type of air preheater, which is mainly composed of a rotor, a shell, a sealing device and the like, the rotor rotates slowly, and a large number of heat storage elements are arranged therein, when flue gas passes through the air preheater, the flue gas flows in the heat storage elements, and heat is transferred to the heat storage elements, with the rotation of the rotor, the heated heat storage elements are turned to the air passage side, and the air absorbs the heat of the heat storage elements in the flowing process, so as to realize the preheating of the air.

[0003] For the SCR flue gas denitration technology, ammonia and nitrogen oxide are difficult to be mixed completely, and escape is inevitable, when the escape rate exceeds the standard, ammonia reacts with sulfur trioxide to generate ammonium bisulfate to block the air preheater, which affects the safe and economic operation of the unit, according to the reversible characteristics of ammonium bisulfate with temperature change (generally, ammonium bisulfate is in solid state below 147 DEG C, in liquid state between 147 DEG C and 207 DEG C, and in gaseous state above 207 DEG C), the air preheater dry burning technology can be applied in operation to adjust and control the outlet temperature of the air preheater to be above 207 DEG C, so as to promote the ammonium bisulfate to be in gaseous state and then be carried out by high-speed flue gas, and the ammonium bisulfate adhering on the heat exchange elements of the air preheater is removed, so as to achieve the effect of eliminating the blockage and realize the continuous safe, energy-saving and environmentally-friendly operation of the unit.

[0004] In the operation process of the air preheater related baffle, there is a close fluid mechanics association between the fan and the baffle, when the air baffle is closed too fast, the air flow will be rapidly reduced, which will cause the temperature field in the air preheater to change sharply, if the temperature in the air preheater is originally in the state of liquid or gaseous state of ammonium bisulfate (above 147 DEG C), the rapid closing of the air baffle can cause the temperature to drop rapidly, according to the characteristics of ammonium bisulfate, when the temperature drops below 147 DEG C, it will rapidly solidify into solid state, this sudden state change will cause the ammonium bisulfate to rapidly solidify and adhere on the surface of the heat exchange element, further aggravating the blockage degree, because the solid-state ammonium bisulfate is more difficult to be carried away by flue gas than liquid or gaseous state, and its adhesion on the surface of the heat exchange element is stronger, which will make the existing blockage problem more serious. UTILITY MODEL CONTENTS

[0005] In view of the deficiencies of the prior art, the utility model provides a rotary air preheater, which solves the problems in the above background.

[0006] To achieve the above object, the utility model discloses the following technical scheme to realize: a rotary air preheater, including air preheater body, air preheater body includes rotor cover, primary air inlet, primary air outlet, secondary air inlet, secondary air outlet, flue gas inlet and flue gas outlet, the primary air outlet, secondary air outlet and flue gas inlet all rotate the installation rotatory lever, and the outside of a plurality of rotatory lever is fixedly connected with primary air baffle, secondary air baffle and flue gas baffle respectively, and the rotatory lever at flue gas baffle installs the transmission mechanism for controlling its rotation, and the driving shaft of transmission mechanism is at low position, and with the outside rotation connection of primary air outlet, and the rotatory lever at driving shaft, secondary air baffle and the rotatory lever at flue gas inlet all install worm wheel, and the outside of worm wheel is engaged with the worm for rotating.

[0007] The sleeve is fixedly connected on the worm close to the primary air outlet, and the driving mechanism for controlling the rotation of the sleeve is installed on the rotor cover, and the polygonal slide block of the driving mechanism is slidably connected with the sleeve, and the handle for manually controlling the rotation of the worm close to the primary air outlet is further installed on the worm.

[0008] Preferably, the outside of the primary air outlet, the secondary air outlet and the flue gas inlet is fixedly installed with a connecting piece, and the three worms are rotatably connected with the connecting pieces close thereto.

[0009] Preferably, the transmission mechanism further comprises two rotating wheels and a multi-groove belt, and the two rotating wheels are fixed with the rotatory lever and the worm respectively, and the two rotating wheels are drivingly connected through the multi-groove belt.

[0010] Preferably, the driving mechanism further comprises a driving motor, a rotating drum and a push piece, the driving motor is fixed with the rotor cover, the rotating drum is fixed with the output shaft of the driving motor, the push piece is fixed with the polygonal slide block, and the polygonal slide block is slidably connected with the rotating drum.

[0011] Preferably, the number of the rotatory lever at the flue gas inlet and the flue gas baffle is a plurality, the rotatory lever at the flue gas inlet is fixedly connected with a fixing piece, one end of the fixing piece is L-shaped, and the one end of the plurality of fixing pieces is rotatably connected with a horizontal plate.

[0012] Compared with the prior art, the utility model possess following beneficial effect: adopt the transmission mode that worm drive worm gear rotation, because big transmission ratio makes the rotation speed of primary baffle, secondary baffle and smoke baffle slow, realizes slow closing, thereby effectively avoids a series of problems caused by baffle closing too fast, such as fan stall, combustion instability etc.;After primary baffle closes to 70%, adopt the mode of hand -operated adjustment, and operating personnel can accurately adjust according to the sound of on -the -spot fan operation, vibration condition and instrument data, better balance primary air supply and combustion demand, guarantee combustion stability, the self -locking of worm drive ensures that in the closing process, it will not be accidentally fast closed or opened due to the external force interference such as flue gas pressure, vibration, always according to the setting speed steady closing, reduce the risk of closing out of control caused by external factors, maintain combustion and ventilation system stable operation. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 It is whole structure schematic diagram of the utility model;

[0014] Figure 2 It is rotor cover structure schematic diagram of the utility model;

[0015] Figure 3 It is flue gas baffle structure schematic diagram of the utility model;

[0016] Figure 4 It is primary air baffle structure schematic diagram of the utility model;

[0017] Figure 5 It is secondary air baffle structure schematic diagram of the utility model.

[0018] Wherein: 1, air preheater body;101, rotor cover;102, primary air inlet;103, primary air outlet;104, secondary air inlet;105, secondary air outlet;106, flue gas inlet;107, flue gas outlet;111, central rotor;112, truss;113, flue gas compartment;114, primary air compartment;115, secondary air compartment;2, rotating rod;3, primary air baffle;4, secondary air baffle;5, flue gas baffle;6, transmission mechanism;601, driving shaft;602, rotating wheel;603, multi -slot belt;7, worm wheel;8, worm;9, sleeve;10, driving mechanism;110, polygonal slide block;120, driving motor;130, rotating drum;140, push piece;11, handle;12, connecting piece;13, fixed part;14, cross plate. DETAILED DESCRIPTION

[0019] For example Figures 1-5As shown, a rotary air preheater, comprising an air preheater body 1, the air preheater body 1 comprising a rotor cover 101, a primary air inlet 102, a primary air outlet 103, a secondary air inlet 104, a secondary air outlet 105, a flue gas inlet 106 and a flue gas outlet 107, the rotor cover 101 is used for installing a central rotor 111, a truss 112, a flue gas compartment 113, a primary air compartment 114, a secondary air compartment 115, the primary air outlet 103, the secondary air outlet 105 and the flue gas inlet 106 are rotatably connected with rotating rods 2, the outer sides of the rotating rods 2 are respectively fixedly connected with primary air baffles 3, secondary air baffles 4 and flue gas baffles 5, the rotating rod 2 at the flue gas baffle 5 is provided with a transmission mechanism 6 for controlling the rotation thereof, the transmission mechanism 6 further comprises two rotating wheels 602 and a multi-groove belt 603, the two rotating wheels 602 are respectively fixed with the rotating rod 2 and a worm gear 7, the two rotating wheels 602 are drivingly connected through the multi-groove belt 603, when the worm gear 7 rotates, the rotating rod 2 at the flue gas baffle 5 can be driven to rotate through the transmission mechanism 6, thereby causing the flue gas baffle 5 to rotate, the driving shaft 601 of the transmission mechanism 6 is located at a low position and is rotatably connected with the outer side of the primary air outlet 103, the driving shaft 601, the rotating rod 2 at the secondary air baffle 4 and one of the rotating rods 2 at the flue gas inlet 106 are all provided with the worm gear 7, the outer side of the worm gear 7 is meshingly connected with a worm 8 for rotation, the outer sides of the primary air outlet 103, the secondary air outlet 105 and the flue gas inlet 106 are fixedly provided with connecting pieces 12, the three worms 8 are rotatably connected with the connecting pieces 12 close thereto, the connecting pieces 12 are used for providing support force for the worms 8, so as to ensure that the worms 8 can stably rotate the rotating rod 2 at the flue gas inlet 106, the number of the flue gas baffles 5 is several and they are equidistantly arranged, the rotating rod 2 at the flue gas inlet 106 is fixedly provided with a fixing piece 13, one end of the fixing piece 13 is L-shaped, one end of the fixing piece 13 is rotatably connected with a horizontal plate 14, when one of the flue gas baffles 5 rotates, the remaining flue gas baffles 5 can also rotate.

[0020] The worm 8 near the primary air outlet 103 is fixedly connected with a sleeve 9, the rotor cover 101 is provided with a driving mechanism 10 for controlling the rotation of the sleeve 9, the driving mechanism 10 further comprises a driving motor 120, a rotating drum 130 and a push piece 140, the driving motor 120 is fixed with the rotor cover 101, the rotating drum 130 is fixed with the output shaft of the driving motor 120, the push piece 140 is fixed with the polygonal slide block 110, the polygonal slide block 110 is slidably connected with the rotating drum 130, the driving motor 120 can provide power for the rotation of the primary air baffle 3, when the flue gas baffle 5 is closed by 70%, the polygonal slide block 110 can be slid along the inner wall of the rotating drum 130 and separated from the sleeve 9 by pushing the push piece 140, at this time, the primary air baffle 3 is closed in a manual rotation mode, the polygonal slide block 110 of the driving mechanism 10 is slidably connected with the sleeve 9, and the handle 11 for manually controlling the rotation of the worm 8 near the primary air outlet 103 is further installed.

[0021] Working principle:

[0022] When it is necessary to close the secondary air outlet 105, the external drive motor 120 is connected to the worm 8 near the secondary air outlet 105, the worm 8 is driven to rotate by the external motor, the worm 8 drives the worm gear 7 to rotate, the worm gear 7 drives the rotating rod 2 to rotate, the rotating rod 2 drives the secondary baffle 4 to rotate, when the secondary baffle 4 rotates, the secondary air outlet begins to close. Similarly, when it is necessary to close the flue gas inlet 106 and the primary air outlet, the worm 8 can drive the worm gear 7 to rotate in the above-mentioned manner, so that the primary baffle 3 and the flue gas baffle 5 rotate and close the primary air outlet and the flue gas inlet 106, respectively. When one of the rotating rods 2 at the flue gas inlet 106 rotates, the fixed part 13 and the horizontal plate 14 are driven to rotate, and the several rotating rods 2 also rotate at this time. At this time, the several flue gas baffles 5 at the flue gas inlet 106 close the flue gas inlet 106, and each flue gas baffle 5 should be at the same level. The contact part of the two adjacent flue gas baffles 5 should be sealed. It should be noted that the worm 8 has a large transmission ratio, the worm 8 is a single-head spiral structure, and the number of teeth of the worm gear 7 is relatively large. The worm 8 needs to rotate many times, and the worm gear 7 will rotate one circle. When used to drive the flue baffle to rotate, the motor drives the worm 8 to rotate. Due to the existence of the transmission ratio, the rotating speed of the worm gear 7 will be reduced, so the rotating speed of the primary baffle 3, the secondary baffle 4 and the flue baffle will also be slowed down accordingly, achieving the effect of slow closing. The worm 8 transmission has self-locking property under certain conditions. When the helix angle of the worm 8 is less than the equivalent friction angle of the worm 8 material, the worm gear 7 cannot drive the worm 8 to rotate in the opposite direction. For example, for the flue baffle, this self-locking property can prevent the baffle from being accidentally quickly closed or opened under the interference of external forces such as flue gas pressure and vibration. During the closing process, it can ensure that the baffle stably closes according to the driving speed of the worm 8, and will not suddenly accelerate due to external factors, thereby achieving slow closing. Similarly, the primary baffle 3 and the secondary baffle 4 can also achieve slow closing, reducing the risk of losing control during the closing process due to external factors, ensuring the safety of the closing operation, and helping to maintain the stable operation of the entire combustion system and ventilation system.

[0023] Subsequently, when the worm 8 near the primary air baffle 3 is rotated and closed, the driving motor 120 needs to drive the rotating drum 130 to rotate, the rotating drum 130 drives the polygonal slider 110 to rotate, the polygonal slider 110 drives the sleeve 9 to rotate, the sleeve 9 drives the worm 8 to rotate, the worm 8 drives the driving shaft 601 to rotate, the driving shaft 601 drives the two rotating wheels 602 to rotate synchronously through the multi-groove belt 603, one of the two rotating wheels 602 drives the rotating rod 2 to rotate, and the rotating rod 2 drives the primary air baffle 3 to rotate, thereby achieving the slow closing of the primary air baffle 3. When the primary air baffle 3 is closed by 70%, the driving motor 120 stops working, then the push piece 140 is pulled to drive the polygonal slider 110 to move and separate from the sleeve 9, thereby releasing the limiting effect between the sleeve 9 and the polygonal slider 110. Then the handle 11 is manually rotated. Since the driving shaft 601 is at a low position, the handle 11 is also at a low position, which is convenient for the operator to operate. The handle 11 can be manually rotated to rotate the worm 8. After the primary air baffle 3 is closed by 70%, the system is more sensitive to the change of the primary air flow. The local manual handle 11 adjustment can achieve very fine control. The operator can accurately adjust the opening of the baffle according to the actual situation on site, such as the running sound and vibration of the fan, and by observing the instrument. The adjustment range can be very small. For example, compared with the automatic control mode, the manual control mode can control the opening adjustment accuracy of the baffle within a smaller range, such as 1%-2% opening change, which can better balance the supply and burning demand of the primary air, and avoid the influence of the slight excess or deficiency of the primary air flow on the combustion stability. Moreover, during the operation of the primary air baffle 3, the secondary air baffle 4 and the flue gas baffle 5 of the air preheater, the air flow will not decrease rapidly due to the slow closing, which will not cause the temperature field in the air preheater to change rapidly. If the temperature in the air preheater is originally above 147℃, which is the liquid or gaseous state of ammonium bisulfate, slow closing of the air baffle will not cause the temperature to drop rapidly. According to the reversible characteristics of ammonium bisulfate with temperature change, ammonium bisulfate is in a solid state below 147℃, in a liquid state between 147-207℃, and in a gaseous state above 207℃. During operation, the air preheater dry burning technology can be applied to adjust and control the air preheater outlet temperature to be above 207℃, so as to promote the ammonium bisulfate to be in a gaseous state and then be carried out by high-speed flue gas, thereby removing the ammonium bisulfate adhering on the air preheater heat exchange element, achieving the effect of eliminating the blockage, and realizing the continuous, safe, energy-saving and environmentally-friendly operation of the unit.

[0024] Finally, it needs to be explained that after closing the secondary air damper 4, the primary air damper 3, the flue gas damper 5 of the flue gas inlet 106 of the air preheater body 1, the main operator should pay attention to the combustion monitoring, the running mill outlet temperature monitoring; prevent the mill outlet temperature from being low due to the wind temperature drop to cause the mill to be blocked and the mill to jump; control the temperature rising rate of the air preheater outlet flue gas temperature, prevent the air preheater from being stuck due to uneven expansion; after the flue gas temperature rises, check the air preheater body 1 for no abnormal sound, check the air preheater outlet to the induced draft fan outlet flue for no abnormality, and control the flue gas temperature to be greater than 210 DEG C and less than or equal to 230 DEG C; after the flue gas temperature is stable, continue to comprehensively check the above-mentioned system, stop the test immediately when the abnormality is found, and restore the original operation mode; prepare the fire extinguishing equipment in advance for the flue gas ignition event accident anticipation.

[0025] Although the embodiments of the present application have been shown and described, it is to be understood that for the purpose of the present application, the embodiments can be changed, modified, replaced and varied in many ways without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A rotary air preheater, comprising an air preheater body (1), the air preheater body (1) comprising a rotor cover (101), a primary air inlet (102), a primary air outlet (103), a secondary air inlet (104), a secondary air outlet (105), a flue gas inlet (106), and a flue gas outlet (107), characterized in that: Rotating rods (2) are rotatably installed on the primary air outlet (103), secondary air outlet (105) and flue gas inlet (106). A primary air baffle (3), a secondary air baffle (4) and a flue gas baffle (5) are fixedly connected to the outer side of several rotating rods (2). A transmission mechanism (6) for controlling its rotation is installed on the rotating rod (2) at the flue gas baffle (5). The drive shaft (601) of the transmission mechanism (6) is in a low position and is rotatably connected to the outer side of the primary air outlet (103). A worm gear (7) is installed on one of the rotating rods (2) at the drive shaft (601), the secondary air baffle (4) and the flue gas inlet (106). A worm (8) for rotation is meshed on the outer side of the worm gear (7). A sleeve (9) is fixedly connected to the worm (8) near the primary air outlet (103). A drive mechanism (10) for controlling the rotation of the sleeve (9) is installed on the rotor cover (101). The polygonal slider (110) of the drive mechanism (10) is slidably connected to the sleeve (9). A handle (11) for manually controlling its rotation is also installed on the worm (8) near the primary air outlet (103).

2. A rotary air preheater according to claim 1, characterized in that: Connectors (12) are fixedly installed on the outer sides of the primary air outlet (103), secondary air outlet (105) and flue gas inlet (106), and the three worm gears (8) are rotatably connected to the connectors (12) that are close to them.

3. A rotary air preheater according to claim 1, characterized in that: The transmission mechanism (6) further includes two rotating wheels (602) and a grooved belt (603). The two rotating wheels (602) are fixed to the rotating rod (2) and the worm gear (7) respectively, and the two rotating wheels (602) are connected by the grooved belt (603).

4. A rotary air preheater according to claim 1, characterized in that: The drive mechanism (10) further includes a drive motor (120), a rotating drum (130), and a pusher plate (140). The drive motor (120) is fixed to the rotor cover (101), the rotating drum (130) is fixed to the output shaft of the drive motor (120), the pusher plate (140) is fixed to the polygonal slider (110), and the polygonal slider (110) is slidably connected to the rotating drum (130).

5. A rotary air preheater according to claim 1, characterized in that: The number of rotating rods (2) and flue gas baffles (5) at the flue gas inlet (106) are several. Each rotating rod (2) at the flue gas inlet (106) is fixedly connected to a fixing member (13). One end of the fixing member (13) is L-shaped, and one end of each fixing member (13) is rotatably connected to a horizontal plate (14).

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