Transformation method of pull rod sealing device of medium-speed coal mill

Abstract

The invention discloses a transformation method of a pull rod sealing device of a medium-speed coal mill, which belongs to the field of pull rod sealing of the medium-speed coal mill, and comprises the following steps: when the medium-speed coal mill is overhauled, forming two holes in the bottom of a pull rod sealing cavity at the upper end of an overhauling platform, and taking out an originally worn metal sealing device on a pull rod; the diameter of the pull rod and the inner diameter of a pull rod sealing cavity are measured, and a rubber ring provided with a center hole and an inclined opening is manufactured; a cut rubber ring is put into the pull rod sealing cavity from one hole and sleeves the pull rod, and two fixing rods for preventing the rubber ring from falling off are welded at the lower end of the position, sleeved with the rubber ring, of the pull rod in parallel; the two formed holes are welded in situ through iron sheets taken down when the holes are formed, so that the pull rod sealing cavity is restored; the other two pull rod sealing devices of the medium-speed coal mill are implemented according to the steps. The sealing performance of the pull rod can be improved, pulverized coal and other impurities can be effectively prevented from entering gaps of the pull rod, and normal operation of a coal mill is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of tie rod seals for medium-speed coal mills, in particular to a method for modifying a tie rod seal device for a medium-speed coal mill. Background Art

[0002] The coal injection operation area uses a medium-speed coal mill to grind coal. In the coal feeding stage, the raw coal is fed into the medium-speed coal mill through the coal feeder. The working principle of the medium-speed coal mill is that the coal falls into the middle of the turntable from the coal drop pipe, and moves to the edge of the turntable by the centrifugal force and is crushed by the roller. There is a retaining ring on the edge of the turntable to ensure that there is a certain thickness of coal layer in the turntable, which can improve the coal grinding efficiency. Hot air is sent into the turntable by the wind ring around the turntable, carrying coal powder into the coarse powder separator on the top of the coal mill. Unqualified coal powder returns to the turntable to continue grinding, and the stone coal falls into the stone coal storage box from the wind ring. The main factors affecting the operation of the medium-speed flat disc mill are raw coal moisture, raw coal hardness, coal mill speed, coal mill ventilation volume, spring compression, etc.

[0003] The hydraulic variable loading system of medium-speed coal mill is an important part of medium-speed coal mill, which consists of high-pressure oil pump station, oil pipeline, accumulator, loading oil cylinder, tie rod and other components. Its functions are as follows: The hydraulic system provides the grinding roller with grinding pressure that varies with the load. The tie rod of the coal mill is the main equipment of the coal mill loading system and is very important in the system. The working area of ​​the tie rod of the coal mill has high dust concentration and high tensile stress, and has high requirements for sealing.

[0004] When the tie rod seal of the medium-speed coal mill is poor, the most direct phenomenon is the leakage of coal powder. Poor tie rod seal may also lead to a decrease in the operating efficiency of the coal mill. During the recent maintenance work, it was found that the pressure difference of the coal mill was low due to the loose tie rod seal. Low pressure difference usually means insufficient ventilation inside the coal mill, which will cause uneven particle size distribution of coal powder during the grinding process. Low pressure difference may also lead to a decrease in the grinding capacity of the coal mill. Poor ventilation increases the thickness of the coal powder layer between the grinding disc and the grinding roller, increases the grinding resistance, and thus reduces the output of the coal mill.

[0005] However, the existing design of the tie rod seal of the coal mill mainly consists of an upper sealing sleeve, an upper sealing clamp, a lower sealing packing and a sealing air system made of metal. When the coal mill tie rod seal is in operation, the horizontal and axial shaking occurs, the tie rod is easily damaged, the sealing gap increases, and the coal powder leaks out along the tie rod, which cannot meet the requirements of the coal mill for the tie rod. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a modification method for a tie rod sealing device of a medium-speed coal mill, which can improve the sealing performance of the tie rod and effectively prevent coal powder and other impurities from entering the gap of the tie rod, thereby ensuring the normal operation of the coal mill.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is: A method for modifying a rod sealing device of a medium-speed coal mill comprises the following steps: Step 1: When the medium-speed coal mill is overhauled, two holes are opened at the bottom of the tie rod sealing cavity at the upper end of the overhaul platform to remove the original worn metal sealing device on the tie rod; Step 2, measuring the diameter of the tie rod and the inner diameter of the tie rod sealing cavity, and making a rubber ring with a center hole and an oblique opening; the center hole matches the outer diameter of the tie rod; the oblique opening enables the rubber ring to be sleeved on the tie rod; Step 3, putting the cut rubber ring into the tie rod sealing cavity through one of the holes and sleeve it on the tie rod, and welding two first fixing rods and second fixing rods in parallel at the lower end of the tie rod where the rubber ring is sleeved to prevent the rubber ring from falling off; Step 4, the two holes opened in step 1 are welded in situ with the iron sheet removed when the holes are opened, so that the tie rod sealing cavity is restored; Step 5, modify and implement the other two tie rod sealing devices of the medium speed coal mill according to steps 1-4.

[0008] A further improvement of the technical solution of the present invention is that the two holes include a first hole arranged on the front side of the tie rod sealing cavity and a second hole arranged on the side of the tie rod sealing cavity; the size of the first hole is larger than the size of the second hole.

[0009] A further improvement of the technical solution of the present invention is that the size of the first hole is 40cm×25cm; the size of the second hole is 25cm×15cm.

[0010] A further improvement of the technical solution of the present invention is that the thickness of the rubber ring is 50-60 mm.

[0011] A further improvement of the technical solution of the present invention is that the rubber ring is made of waste belts.

[0012] A further improvement of the technical solution of the present invention is that the center hole of the rubber ring and the pull rod are in interference fit.

[0013] A further improvement of the technical solution of the present invention is that the outer diameter of the rubber ring is interference fit with the tie rod sealing cavity.

[0014] A further improvement of the technical solution of the present invention is that the two holes are cut by a cutting gun, and the cut iron sheet at the hole of the tie rod sealing cavity is retained.

[0015] A further improvement of the technical solution of the present invention is that: the first fixing rod and the second fixing rod are respectively welded to both sides of the pull rod; both ends of the first fixing rod and the second fixing rod are respectively welded to the inner wall of the pull rod sealing cavity.

[0016] A further improvement of the technical solution of the present invention is that both the first fixing rod and the second fixing rod are made of steel bars.

[0017] Due to the adoption of the above technical solution, the technical progress achieved by the present invention is: 1. The present invention uses a rubber ring to replace the original worn metal sealing device. The rubber ring as a tie rod seal can maintain stable performance in harsh working environments and extend the service life of the tie rod seal; it can improve the sealing performance of the tie rod, reduce leakage and energy consumption, and enhance the stability and safety of the equipment; it can effectively prevent coal powder and other impurities from entering the gap of the tie rod, thereby ensuring the normal operation of the coal mill.

[0018] 2. The present invention opens two holes in the tie rod sealing cavity, which not only facilitates the removal of the original worn metal sealing device, but also facilitates the operator to perform subsequent replacement of the rubber ring and welding of the fixing rod, thereby cleverly and quickly realizing the transformation of the tie rod sealing device.

[0019] 3. The modification method of the tie rod sealing device of a medium-speed coal mill provided by the present invention solves the problems caused by the existing sealing technology, such as the horizontal and axial shaking of the tie rod sealing device of the coal mill during operation of the equipment, the easy damage of the tie rod, the increase of the sealing gap, and the leakage of coal powder along the tie rod, which cannot meet the requirements of the coal mill for the tie rod; it prevents the problem of loose tie rod sealing device of the medium-speed coal mill, thereby avoiding the leakage of coal powder, affecting the incomplete combustion of blast furnace coal powder, and causing the medium-speed coal mill to be too hot and unable to operate normally. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work. Figure 1 It is a schematic diagram of the modified structure of a tie rod sealing device for a medium-speed coal mill according to an embodiment of the present invention; Figure 2 is a schematic diagram of the structure of a rubber ring in an embodiment of the present invention; Among them, 1. pull rod; 2. pull rod sealing cavity; 3. rubber ring; 3-1. center hole; 3-2. oblique mouth; 4. first fixing rod; 5. second fixing rod. DETAILED DESCRIPTION

[0021] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or apparatus.

[0022] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0023] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "several" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0024] The present invention is further described in detail below with reference to the accompanying drawings and embodiments: like Figure 1-2 As shown, a method for modifying a rod sealing device of a medium-speed coal mill comprises the following steps: Step 1: During the maintenance of the medium-speed coal mill, two holes are opened at the bottom of the tie rod sealing chamber 2 at the upper end of the maintenance platform to remove the original worn metal sealing device on the tie rod 1; Step 2, measure the diameter of the tie rod 1 and the inner diameter of the tie rod sealing cavity 2, and make a rubber ring 3 with a center hole 3-1 and an oblique mouth 3-2; the center hole 3-1 matches the outer diameter of the tie rod 1; the oblique mouth 3-2 enables the rubber ring 3 to be mounted on the tie rod 1; the rubber ring 3 is used as a tie rod seal because it has excellent sealing performance, the rubber material itself has good elasticity and plasticity, can fit tightly to the surface of the tie rod, and form an effective sealing layer, which can effectively prevent coal powder and other impurities from entering the gap of the tie rod, thereby ensuring the normal operation of the medium-speed coal mill.

[0025] Step 3, put the cut rubber ring 3 into the tie rod sealing cavity 2 through one of the holes and put it on the tie rod 1, and weld two first fixing rods 4 and second fixing rods 5 in parallel at the lower end of the tie rod 1 where the rubber ring 3 is put to prevent the rubber ring 3 from falling off; Step 4, the two holes opened in step 1 are welded in situ with the iron sheet removed when the holes are opened, so that the tie rod sealing cavity 2 is restored; Step 5, modify and implement the other two tie rod sealing devices of the medium speed coal mill according to steps 1-4.

[0026] Furthermore, the two holes include a first hole arranged on the front side of the tie rod sealing cavity 2 and a second hole arranged on the side of the tie rod sealing cavity 2; the size of the first hole is larger than the size of the second hole.

[0027] Furthermore, the size of the first hole is 40cm×25cm; the size of the second hole is 25cm×15cm. Since the internal space of the tie rod sealing chamber 2 of the medium-speed coal mill is small and the working space is limited, only two holes can be opened outside the tie rod sealing chamber 2 with a cutting gun, and the two holes can be used to remove the original worn metal sealing device. At the same time, the setting of the two holes of different sizes facilitates the operation of the operator. One hole can be used for hand support and the other hole can be used for operation, and the same applies to the subsequent operations.

[0028] Furthermore, the thickness of the rubber ring 3 is 50-60 mm, which ensures the sealing strength of the rubber ring 3 and the wear resistance.

[0029] Furthermore, the rubber ring 3 is made of waste belts. Specifically, the diameter of the pull rod 1 and the inner diameter of the pull rod sealing cavity 1 are measured, the corresponding dimensions are drawn on the waste belt, and the center hole 3-1 and the bevel 3-2 are cut out with a belt knife so that the rubber ring can be put into the hole and put on the pull rod 1. The rubber ring 3 made of waste belts can maintain stable performance in harsh working environments and extend the service life of the pull rod seal. Because the rubber ring 3 is thick enough, the bevel 3-2 does not need to be connected and will not affect the sealing effect of the pull rod 1.

[0030] Furthermore, the center hole 3 - 1 of the rubber ring 3 and the pull rod 1 are in interference fit to ensure the sealing effect of the rubber ring 3 .

[0031] Furthermore, the outer diameter of the rubber ring 3 is interference fit with the tie rod sealing cavity 2 to ensure the sealing effect of the rubber ring 3 .

[0032] Furthermore, the two holes are cut by a cutting gun, and the cut iron sheet at the hole of the tie rod sealing cavity 2 is retained.

[0033] Further, such as Figure 1 As shown, the first fixing rod 4 and the second fixing rod 5 are respectively welded to the two sides of the tie rod 1 ; both ends of the first fixing rod 4 and the second fixing rod 5 are respectively welded to the inner wall of the tie rod sealing cavity 2 .

[0034] Furthermore, the first fixing rod 4 and the second fixing rod 5 are both made of steel bars, which are commonly used in construction sites and are easy to make.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for modifying a rod sealing device of a medium-speed coal mill, characterized in that: The following steps are involved: Step 1: during the maintenance of the medium-speed coal mill, two holes are opened at the bottom of the tie rod sealing cavity (2) at the upper end of the maintenance platform to remove the original worn metal sealing device on the tie rod (1); Step 2, measuring the diameter of the tie rod (1) and the inner diameter of the tie rod sealing cavity (2), and manufacturing a rubber ring (3) provided with a center hole (3-1) and an oblique opening (3-2); the center hole (3-1) matches the outer diameter of the tie rod (1); the oblique opening (3-2) enables the rubber ring (3) to be sleeved on the tie rod (1); Step 3, inserting the cut rubber ring (3) into the tie rod sealing cavity (2) through one of the holes and fitting it onto the tie rod (1), and welding two first fixing rods (4) and second fixing rods (5) in parallel at the lower end of the tie rod (1) where the rubber ring (3) is fitted, so as to prevent the rubber ring (3) from falling off; Step 4, the two holes opened in step 1 are welded in situ with the iron sheet removed when the holes were opened, so that the tie rod sealing cavity (2) is restored; Step 5, modify and implement the other two tie rod sealing devices of the medium speed coal mill according to steps 1-4.

2. The method for modifying the rod sealing device of a medium-speed coal mill according to claim 1, characterized in that: The two holes comprise a first hole arranged on the front side of the tie rod sealing cavity (2) and a second hole arranged on the side side of the tie rod sealing cavity (2); the size of the first hole is larger than the size of the second hole.

3. The method for modifying the rod sealing device of a medium-speed coal mill according to claim 2, characterized in that: The size of the first hole is 40cm×25cm; the size of the second hole is 25cm×15cm.

4. The method for modifying the rod sealing device of a medium-speed coal mill according to claim 1, characterized in that: The thickness of the rubber ring (3) is 50-60 mm.

5. The method for modifying the rod sealing device of a medium-speed coal mill according to claim 1, characterized in that: The rubber ring (3) is made of waste belts.

6. The method for modifying the rod sealing device of a medium-speed coal mill according to claim 1, characterized in that: The central hole (3-1) of the rubber ring (3) and the pull rod (1) are in interference fit.

7. The method for modifying the rod sealing device of a medium-speed coal mill according to claim 1, characterized in that: The outer diameter of the rubber ring (3) is in interference fit with the tie rod sealing cavity (2).

8. The method for modifying the rod sealing device of a medium-speed coal mill according to claim 1, characterized in that: The two holes are cut using a cutting gun, and the cut iron sheet at the hole of the pull rod sealing cavity (2) is retained.

9. The method for modifying the rod sealing device of a medium-speed coal mill according to claim 1, characterized in that: The first fixing rod (4) and the second fixing rod (5) are respectively welded to two sides of the tie rod (1); and both ends of the first fixing rod (4) and the second fixing rod (5) are respectively welded to the inner wall of the tie rod sealing cavity (2).

10. The method for modifying the rod sealing device of a medium-speed coal mill according to claim 9, characterized in that: The first fixing rod (4) and the second fixing rod (5) are both made of steel bars.

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