A fillerless discharge seal structure of a center-discharge rotary dryer

Abstract

The application discloses a packing-free sealing structure of a center discharging rotary dryer and belongs to the field of industrial production equipment. In order to solve the problems existing in the traditional discharging sealing structure, the sealing structure comprises a sealing gas pipeline, a front sealing structure arranged at one end of a main body of the center discharging rotary dryer and a rear sealing structure arranged at the other end of the main body. The application has the advantages that the gas sealing is adopted at the dynamic and static friction positions of the machine, the problems of uneven packing, heat generation at the sealing position and friction caused by the traditional packing sealing are solved, and the problem of adding new impurities caused by adding lubricating oil is avoided. The gas sealing provided by the application is clean and has better effect.

Description

Technical Field

[0001] This invention belongs to the field of industrial production equipment, and particularly relates to the discharge sealing structure of rotary dryers for chemical powders such as POM, PPE, HDPE, PTA, and PPS, especially the discharge sealing structure of POM rotary dryers. Background Technology

[0002] The discharge sealing structure of the center-discharge rotary dryer in existing production equipment is a traditional V-type packing + square packing + gas distribution ring + oil distribution ring + sealing gas + cooling water structure to prevent powder leakage. The center-discharge rotary dryer is a large machine, and during the drying process, the dryer rotates while drying, while the discharge sealing structure is fixed. Therefore, there is dynamic and static friction between the discharge structure and the rotary dryer. Long-term friction during production leads to uneven packing gland clearance and packing overheating. In addition, the vibration of large machinery during operation can also cause damage and uneven packing. Traditional machinery addresses friction and overheating by adding lubricating oil and using cooling water for heat exchange. While these methods solve the friction and overheating problems, they undoubtedly introduce new issues. The use of packing for sealing, along with the addition of lubricating oil, easily introduces new impurities into the production system, leading to a decrease in the purity of the final chemical product and an increase in impurities.

[0003] For example, due to the low density and high strength of POM powder, and the presence of methanol and paraformaldehyde as solvents in wet POM materials, POM materials are more prone to dust generation and can more quickly disrupt the sealed environment compared to materials such as HDPE and PTA. Therefore, during the POM production process, rotary dryers are prone to issues such as filler overheating, filler debris, and lubricating oil contaminating the material, leading to material leakage at the seals and a decline in material quality. Summary of the Invention

[0004] A fillerless sealing structure for a center-discharge rotary dryer includes a sealing gas pipe, a front sealing structure located at one end of the main body of the center-discharge rotary dryer, and a rear sealing structure located at the other end of the main body. The front and rear sealing structures each include a rotating bushing, a jacketed labyrinth box located on the rotating bushing, and a fixed friction plate located between the jacketed labyrinth box and the rotating bushing. An annular cavity is formed between the rotating bushing and the jacketed labyrinth box, and one or more outer annular grooved cavities located outside the annular cavity and one or more inner annular grooved cavities located inside the annular cavity. The number of inner annular grooved cavities is greater than the number of outer annular grooved cavities.

[0005] Furthermore, the front sealing structure includes a first rotating bushing connected to the main body, a first jacketed labyrinth box disposed on the first rotating bushing, and a first fixed friction plate disposed outside the first jacketed labyrinth box that can contact the first rotating bushing to form a sealing contact; a first annular cavity is formed between the first jacketed labyrinth box and the first rotating bushing, and one or more first annular grooved cavities disposed outside the first annular cavity and one or more second annular grooved cavities disposed inside the first annular cavity, wherein the number of second annular grooved cavities is greater than the number of first annular grooved cavities.

[0006] Furthermore, the front sealing structure also includes a first outer bushing disposed above the first jacket labyrinth box, and a second annular cavity is formed between the first outer bushing and the first jacket labyrinth box.

[0007] Furthermore, the first rotating bushing is provided with a first smooth protrusion that mates with the bottom of the first fixed friction plate.

[0008] Furthermore, a first friction plate pressure plate is provided on the outer side of the first fixed friction plate, and the first friction plate pressure plate and the first fixed friction plate are fixed and connected to the front sealing structure by a screw structure.

[0009] Furthermore, the rear sealing structure includes a second rotating bushing, a second jacketed labyrinth located below the second rotating bushing, and a second fixed friction plate located outside the second jacketed labyrinth and in contact with the second rotating bushing to form a sealing connection; a third annular cavity is formed between the second jacketed labyrinth and the second rotating bushing, and one or more third annular grooved cavities located outside the third annular cavity and one or more fourth annular grooved cavities located inside the third annular cavity, wherein the number of fourth annular grooved cavities is greater than the number of third annular grooved cavities.

[0010] Furthermore, the rear sealing structure also includes a second outer bushing located below the second jacket labyrinth box, the second outer bushing having a vent for exhausting air, and a fourth annular cavity formed between the second outer bushing and the second jacket labyrinth box.

[0011] Furthermore, the second outer bushing has a second smooth protrusion at the contact point with the second fixed friction plate, which mates with the bottom of the first fixed friction plate.

[0012] Furthermore, a second friction plate pressure plate is provided on the outer side of the second fixed friction plate, and the second friction plate pressure plate and the second fixed friction plate are fixed to each other and connected to the rear sealing structure by a screw structure.

[0013] The present invention also provides a fillerless sealing method for a center-discharge rotary dryer, the sealing method comprising the following steps: 1) Before starting the machine, continuously introduce sealing gas into the sealing gas pipeline, and push the sealing gas into the front sealing structure and the rear sealing structure to fill it; 2) The sealing gas first enters the first annular cavity, and under the pressure of the subsequently introduced sealing gas, it continues to advance to both the inner and outer sides of the first annular cavity. Since the number of second annular grooved cavities is greater than that of the first annular grooved cavities, the first annular grooved cavities located on the outer side will be filled with sealing gas before the second annular grooved cavities 33. Then the sealing gas will apply pressure to the first fixed friction plate, causing the first fixed friction plate to press tightly against the first rotating bushing 6, and the front sealing structure is completed. 3) The sealing gas continues to advance into the rear sealing structure, filling the third annular cavity. Then, it enters the third and fourth annular grooved cavities. Since the number of third annular grooved cavities is less than that of fourth annular grooved cavities, the outermost third annular grooved cavity is filled first. Then, the sealing gas pushes the second fixed friction plate outward to press tightly against the second rotating bushing, forming a sealing contact between the second rotating bushing and the second fixed friction plate. The rear sealing structure then completes the sealing.

[0014] The beneficial effects of this invention are that by using gas sealing at the dynamic and static friction points of the machine, it solves the problems of uneven packing, heat generation at the sealing point, and friction caused by traditional packing seals, and also avoids the problem of introducing new impurities by adding lubricating oil. The gas seal provided by this invention is clean and has better performance. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall fillerless sealing structure of the present invention; Figure 2 The fillerless sealing structure of the present invention Figure 1 Enlarged schematic diagram of the front sealing structure of section I; Figure 3 The fillerless sealing structure of the present invention Figure 1 Enlarged schematic diagram of the rear sealing structure of Part II. Detailed Implementation

[0016] The present invention will be further explained and described below with reference to the accompanying drawings.

[0017] A fillerless sealing structure for a center-discharge rotary dryer, the sealing structure including a sealing gas pipe, a front sealing structure located at one end of the main body of the center-discharge rotary dryer, and a rear sealing structure located at the other end of the main body. The aforementioned front sealing structure includes a first support sleeve 7 connected to the main body, a first rotating bushing 6 fixed on the first support sleeve 7, a first jacketed labyrinth 3 disposed on the first rotating bushing 6, and a first fixed friction plate 5 disposed outside the first jacketed labyrinth 3 and in contact with the first rotating bushing 6 to form a sealing connection (the first rotating bushing 6 and the first fixed friction plate 5 are interference-fitted). A first annular cavity 31 is formed between the first jacketed labyrinth 3 and the first rotating bushing 6, and one or more first annular grooved cavities 32 disposed outside the first annular cavity 31 and one or more second annular grooved cavities 33 disposed inside the first annular cavity 31. The number of second annular grooved cavities 33 is greater than the number of first annular grooved cavities 32. The first fixed friction plate 5 is connected to the outermost first annular grooved cavity 32. The first annular cavity 31 is provided with a sealing gas inlet, and sealing gas distribution holes are provided between the annular grooved cavities and between the annular grooved cavities. Before the machine starts, sealing gas is introduced through the sealing gas inlet. After the sealing gas enters the first annular cavity 31, it continues to advance towards both the inner and outer sides of the first annular cavity 31 under the action of sealing gas pressure, sequentially filling each grooved cavity (32 / 33). Since the number of second annular grooved cavities 33 is greater than that of first annular grooved cavities 32, the outermost first annular grooved cavity 32 will be filled with sealing gas before the second annular grooved cavity 33. The sealing gas in the outermost first annular grooved cavity 32 will apply pressure to the first fixed friction plate 5, causing the first fixed friction plate 5 to press tightly against the first rotating bushing 6, thus forming a sealed contact between the first fixed friction plate 5 and the first rotating bushing 6. The number of second annular grooved cavities 33 is greater than that of first annular grooved cavities 32, which can quickly form a sealed environment before the machine starts. After the sealed environment is filled, gas is continued to be injected for sealing and isolation.

[0018] Preferably, the sealing structure further includes a first outer bushing 2 disposed above the first jacketed labyrinth 3, the sealing air inlet being disposed on the first outer bushing 2, and a second annular cavity 34 formed between the first outer bushing 2 and the first jacketed labyrinth 3. In this structure, as shown... Figure 2 As indicated by the arrow, before the machine is started, sealing gas is introduced and enters the second annular cavity 34 through the sealing gas inlet. Under the action of the sealing gas pressure, the sealing gas continues to enter the first annular cavity 31 through the through hole on the first jacket labyrinth 3. Then, it first fills the first annular groove cavity 32. The sealing gas in the outermost first annular groove cavity 32 will pressurize the first fixed friction plate 5, so that the first fixed friction plate 5 is pressed tightly against the first rotating bushing 6, thereby forming a sealed contact between the first fixed friction plate 5 and the first rotating bushing 6.

[0019] Preferably, the part of the first rotating bushing 6 that contacts the first fixed friction plate 5 is provided with a first smooth protrusion that matches the bottom of the first fixed friction plate 5. The first fixed friction plate 5 is generally made of rubber material. Under the pressure of the sealing gas, the first fixed friction plate 5 adheres to the outside and presses against the first smooth protrusion, and a sealed contact is formed between the two.

[0020] Preferably, a first friction plate pressure plate 4 is provided on the outer side of the first fixed friction plate 5, and the first friction plate pressure plate 4 and the first fixed friction plate 5 are fixed to each other by a screw structure and connected to the front sealing structure.

[0021] The rear sealing structure includes a second support sleeve 8, a second rotating bushing 9 fixed below the second support sleeve 8, a second jacketed labyrinth 12 located below the second rotating bushing 9, and a second fixed friction plate 10 located outside the second jacketed labyrinth 12 and in contact with the second rotating bushing 9 to form a sealing connection (the second rotating bushing 9 and the second fixed friction plate 10 are interference-fitted). A third annular cavity 121 is formed between the second jacketed labyrinth 12 and the second rotating bushing 9, and one or more third annular grooved cavities 122 located outside the third annular cavity 121 and one or more fourth annular grooved cavities 123 located inside the third annular cavity 121. The number of fourth annular grooved cavities 123 is greater than the number of third annular grooved cavities 122. The second fixed friction plate 10 is in contact with the outermost third annular groove cavity 122, and the third annular cavity 121 is connected to a drain port. Similarly, before the machine is started, the sealing gas is introduced through the sealing gas inlet and then enters the rear sealing structure. The sealing gas fills the third annular cavity 121 and then enters the third annular groove cavity 122 and the fourth annular groove cavity 123 through the sealing gas distribution hole. Since the number of third annular groove cavities 122 is less than that of fourth annular groove cavities 123, the outermost third annular groove cavity 122 is filled first. After the sealing gas fills the third annular groove cavity 122, it pushes against the second fixed friction plate 10 and tightly adheres to the second rotating bushing 9, forming a sealing contact between the second rotating bushing 9 and the second fixed friction plate 10.

[0022] Preferably, the rear sealing structure further includes a second outer bushing 14 located below the second jacketed labyrinth box 12. The second outer bushing 14 has a vent port 13 for venting. A fourth annular cavity is formed between the second outer bushing 14 and the second jacketed labyrinth box 12. In this structure, as shown... Figure 3 As shown, since the sealing gas pipeline has an annular cavity structure, the sealing gas also comes from... Figure 2Before the machine is started, sealing gas is introduced through the sealing gas inlet. The sealing gas enters the fourth annular cavity through the sealing gas pipe, and then enters the third annular cavity 121 through the through hole on the second jacket labyrinth 12. The sealing gas first fills the third annular groove 122. The sealing gas in the outermost third annular groove 122 will press the second fixed friction plate 10, so that the second fixed friction plate 10 is tightly pressed against the second rotating bushing 9. Thus, a sealing contact is formed between the second fixed friction plate 10 and the second rotating bushing 9. At this point, the entire system forms a sealed structure.

[0023] Preferably, the second outer bushing 14 has a second smooth protrusion at the part that contacts the second fixed friction plate 10, which matches the bottom of the first fixed friction plate 5. The second fixed friction plate 10 is generally made of rubber material. Under the pressure of the sealing gas, the second fixed friction plate 10 pushes outward to fit the second smooth protrusion, and the two are in sealed contact.

[0024] Preferably, a second friction plate pressure plate 11 is also provided on the outer side of the second fixed friction plate 10, and the second friction plate pressure plate 11 and the second fixed friction plate 10 are fixed to each other and connected to the rear sealing structure by a screw structure.

Claims

1. A fillerless sealing structure for a center-discharge rotary dryer, the sealing structure comprising a sealing gas pipe, a front sealing structure located at one end of the main body of the center-discharge rotary dryer, and a rear sealing structure located at the other end of the main body; characterized in that, The front sealing structure and the rear sealing structure each include a rotating bushing, a jacketed labyrinth box disposed on the rotating bushing, and a fixed friction plate disposed between the jacketed labyrinth box and the rotating bushing. An annular cavity is formed between the rotating bushing and the jacketed labyrinth box, and one or more outer annular grooved cavities disposed on the outside of the annular cavity and one or more inner annular grooved cavities disposed on the inside of the annular cavity. The number of inner annular grooved cavities is greater than the number of outer annular grooved cavities. The front sealing structure includes a first rotating bushing connected to the main body, a first jacketed labyrinth box disposed on the first rotating bushing, and a first fixed friction plate disposed on the outside of the first jacketed labyrinth box that can contact the first rotating bushing to form a sealing contact. A first annular cavity is formed between the first jacketed labyrinth box and the first rotating bushing, and one or more first annular grooved cavities disposed on the outside of the first annular cavity and one or more second annular grooved cavities disposed on the inside of the first annular cavity. The number of second annular grooved cavities is greater than the number of first annular grooved cavities. The first rotating bushing and the first fixed friction plate are interference-fitted. The rear sealing structure includes a second rotating bushing, a second jacketed labyrinth located below the second rotating bushing, and a second fixed friction plate located outside the second jacketed labyrinth and in contact with the second rotating bushing to form a sealing connection; a third annular cavity is formed between the second jacketed labyrinth and the second rotating bushing, and one or more third annular grooved cavities located outside the third annular cavity and one or more fourth annular grooved cavities located inside the third annular cavity, wherein the number of fourth annular grooved cavities is greater than the number of third annular grooved cavities; the second rotating bushing and the second fixed friction plate are interference-fitted.

2. The fillerless sealing structure of the center-discharge rotary dryer as described in claim 1, characterized in that, The aforementioned front sealing structure further includes a first outer bushing disposed above the first jacket labyrinth, and a second annular cavity is formed between the first outer bushing and the first jacket labyrinth.

3. The fillerless sealing structure of the center-discharge rotary dryer as described in claim 1, characterized in that, The first rotating bushing is provided with a first smooth protrusion that mates with the bottom of the first fixed friction plate.

4. The fillerless sealing structure of the center-discharge rotary dryer as described in claim 1, characterized in that, The first fixed friction plate is further provided with a first friction plate pressure plate on its outer side. The first friction plate pressure plate and the first fixed friction plate are fixed and connected to the front sealing structure by a screw structure.

5. The fillerless sealing structure of the center-discharge rotary dryer as described in claim 1, characterized in that, The rear sealing structure further includes a second outer bushing located below the second jacket labyrinth, the second outer bushing having a vent for exhausting air, and a fourth annular cavity formed between the second outer bushing and the second jacket labyrinth.

6. The fillerless sealing structure of the center-discharge rotary dryer as described in claim 5, characterized in that, The second outer bushing has a second smooth protrusion at the contact point with the second fixed friction plate, which mates with the bottom of the second fixed friction plate.

7. The fillerless sealing structure of the center discharge rotary dryer as described in claim 1, characterized in that, The second fixed friction plate is further provided with a second friction plate pressure plate on its outer side. The second friction plate pressure plate and the second fixed friction plate are fixed to each other by a screw structure and connected to the rear sealing structure.

8. The fillerless sealing method for the fillerless sealing structure of the center discharge rotary dryer as described in claim 1, characterized in that, The sealing method includes the following steps: 1) Before starting the machine, continuously introduce sealing gas into the sealing gas pipeline, and push the sealing gas into the front sealing structure and the rear sealing structure to fill it; 2) The sealing gas first enters the first annular cavity, and under the pressure of the subsequently introduced sealing gas, it continues to advance to both the inner and outer sides of the first annular cavity. Since the number of second annular grooved cavities is greater than that of first annular grooved cavities, the first annular grooved cavities located on the outer side will be filled with sealing gas before the second annular grooved cavities. Then the sealing gas will apply pressure to the first fixed friction plate, causing the first fixed friction plate to press tightly against the first rotating bushing, and the front sealing structure is completed. 3) The sealing gas continues to advance into the rear sealing structure, filling the third annular cavity. Then, it enters the third annular groove cavity and the fourth annular groove cavity. Since the number of third annular groove cavities is less than that of fourth annular groove cavities, the outermost third annular groove cavity is filled first. Then, the sealing gas pushes the second fixed friction plate outward to tightly adhere to the second rotating bushing, forming a sealing contact between the second rotating bushing and the second fixed friction plate. The rear sealing structure then completes the sealing.

Images