Online replacement method for drying cylinder shaft head of paper mill

Abstract

The invention provides an online replacement method for a drying cylinder shaft head of a paper mill. The online replacement method is characterized by comprising the following steps of: 1, performing power failure and safety isolation on equipment; secondly, auxiliary equipment special for the drying cylinder shaft head is selected to conduct auxiliary supporting on the drying cylinder shaft head; thirdly, a new shaft head is replaced; 4, detecting and debugging; the special auxiliary supporting equipment is arranged, the hydraulic cylinders are matched with the supporting rings, the drying cylinder shaft head is replaced more quickly and conveniently, meanwhile, the replaced shaft head can be conveniently moved to a designated position to be maintained, operation is easy and convenient, and the working efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of dryer shaft head maintenance in paper mill, in particular to a dryer shaft head online replacement method in paper mill. BACKGROUND

[0002] In the production of paper mill, the dryer is the core equipment of the drying section (bearing the function of paper dewatering and drying), and the shaft head thereof is a key component connecting the dryer and the transmission system and supporting bearing. If faults such as wear, crack and seal failure occur, the shaft head needs to be replaced in time.

[0003] The current method for replacing the dryer is to use a crown block or a large hoisting device to hoist the dryer away from the drying section, and then hoist the dryer back to the drying section after replacing the shaft head of the dryer. This method for replacing the shaft head of the dryer is troublesome and time-consuming, and the hoisting process is also prone to cause collision damage between dryers.

[0004] The online replacement of the shaft head of the dryer refers to a maintenance method of directly disassembling and installing the shaft head component without hoisting the dryer as a whole from the rack (only stopping the machine without disassembling the dryer body), which can greatly shorten the downtime. SUMMARY

[0005] In view of the above technical problems, the present application provides a dryer shaft head online replacement method in paper mill, which can improve work efficiency.

[0006] The present application provides a dryer shaft head online replacement method in paper mill, characterized by comprising the following steps: Step 1: stop the equipment and isolate the safety; Step 2: select a dryer shaft head special auxiliary equipment to assist in supporting; Step 3: replace the new shaft head; Step 4: detection and debugging.

[0007] The specific steps of step 1 include: 1) stop the machine and cut off the power: stop the dryer transmission motor and the steam heating system, close the dryer steam inlet valve and the drain valve, and ensure that the dryer completely stops running; 2) safety protection: set warning signs and protective fences in the operation area, and clean the surrounding debris; the operator wears a safety helmet, anti-impact gloves and anti-slip shoes; 3) medium emptying: completely empty the residual steam and condensate water in the dryer, and confirm that the pressure in the dryer is 0 MPa through the pressure gauge to avoid steam leakage during disassembly.

[0008] The dryer shaft head special auxiliary equipment in step 2 includes a movable support bin, the movable support bin is internally fixedly connected with a support table, and the support table is connected with a hydraulic support mechanism. The hydraulic support mechanism comprises a hydraulic cylinder A, a hydraulic cylinder B, a hydraulic cylinder C, a supporting ring B, a supporting ring C, a supporting ring A and a small telescopic air cylinder, the hydraulic cylinder A, the hydraulic cylinder B and the hydraulic cylinder C are fixedly installed in a linear type on a supporting table, the telescopic end of the hydraulic cylinder A is fixedly connected with the supporting ring A, the left and right sides of the supporting ring A are fixedly connected with the small telescopic air cylinders, the telescopic end of each small telescopic air cylinder is connected with another supporting ring A, the telescopic end of the hydraulic cylinder B is fixedly connected with the supporting ring B, the telescopic end of the hydraulic cylinder C is fixedly connected with the supporting ring C, the bottoms of the hydraulic cylinder A, the hydraulic cylinder B and the hydraulic cylinder C are connected with an oil supply main pipe through an oil supply branch pipe and a control valve, and the oil supply main pipe is connected with an oil tank through an oil pump.

[0009] The specific operation steps of the fourth step comprise: 1) static detection: the replaced drying cylinder is detected in radial runout, end face runout and sealing performance; 2) dynamic debugging: the replaced drying cylinder is tested in no-load and load running.

[0010] The movable supporting bin is provided with brake wheels at four corners of the bottom, a traction rod is fixedly connected to the front wall of the movable supporting bin, installation grooves are formed in the left and right sides of the movable supporting bin, a rotating plate is connected to the front and back of each installation groove through a rotating shaft, an adjustable supporting piece is detachably connected to one end of each rotating plate, and a magnetic sticker is arranged on the front wall of each rotating plate.

[0011] The adjustable supporting piece comprises a supporting seat, a threaded rod and a knob, the supporting seat is threadedly connected with the threaded rod, and the threaded rod is threadedly connected with the knob.

[0012] A maintenance door is arranged on one side of the supporting table.

[0013] Pressure sensors are arranged on the inner walls of the supporting ring A, the supporting ring B, the supporting ring C and the small telescopic air cylinder, and the pressure sensors are connected with a controller.

[0014] The method has the advantages that the method for replacing the shaft head of the drying cylinder of the paper mill is provided, the replacement of the shaft head of the drying cylinder is more rapid and convenient through the cooperation of the special auxiliary supporting equipment, the hydraulic cylinders and the supporting rings, the replaced shaft head is conveniently moved to a specified position for maintenance, the operation is simple and convenient, and the working efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The figure is a schematic diagram of the operation process of the method; Figure 2 The figure is a structure diagram of the special auxiliary equipment in use; Figure 3 The figure is a structure diagram of the special auxiliary equipment; Figure 4This is a structural diagram of the dedicated auxiliary equipment of the present invention; Figure 5 This is a schematic diagram of the internal structure of the special auxiliary equipment support platform of the present invention; Figure 6 This is a partial structural diagram of the dedicated auxiliary equipment of the present invention; Figure 7 This is a partial structural diagram of the dedicated auxiliary equipment of the present invention.

[0016] Reference numerals in the attached diagram: 1-Drying cylinder shaft head mounting base; 2-Drying cylinder shaft head; 3-Modible support compartment; 31-Traction rod; 32-Rotating plate; 33-Adjustable support component; 331-Support seat; 332-Threaded rod; 333-Knob; 34-With brake wheel; 4-Support platform; 5-Hydraulic cylinder A; 6-Hydraulic cylinder B; 7-Hydraulic cylinder C; 8-Support ring B; 9-Support ring C; 10-Support ring A; 11-Small telescopic cylinder; 12-Oil tank; 13-Oil pump; 14-Main oil supply pipe; 15-Branch oil supply pipe; 16-Control valve; 17-Inspection door. Detailed Implementation

[0017] Example 1

[0018] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings.

[0019] like Figures 2-7 As shown, the special auxiliary equipment for the drying cylinder shaft head includes a movable support chamber 3, a support platform 4 is fixedly connected inside the movable support chamber 3, and the support platform 4 is connected to a hydraulic support mechanism. The hydraulic support mechanism includes hydraulic cylinders A5, B6, and C7, support rings B8, C9, and A10, as well as small telescopic cylinders 11. Hydraulic cylinders A5, B6, and C7 are fixedly mounted in a straight line on the support platform 4. The telescopic end of hydraulic cylinder A5 is fixedly connected to support ring A10. Small telescopic cylinders 11 are fixedly connected to the left and right sides of support ring A10. The telescopic end of each small telescopic cylinder 11 is connected to another support ring A10. The telescopic end of hydraulic cylinder B6 is fixedly connected to support ring B8, and the telescopic end of hydraulic cylinder C7 is fixedly connected to support ring C9. The bottoms of hydraulic cylinders A5, B6, and C7 are all connected to the main oil supply pipe 14 through oil supply branch pipes 15 and control valves 16. The main oil supply pipe 14 is connected to the oil tank 12 through an oil pump 13.

[0020] The movable support compartment 3 has braked wheels 34 installed at the four corners of its bottom. The front wall of the movable support compartment 3 is fixedly connected to a traction rod 31. The movable support compartment 3 has mounting slots on its left and right sides. Each mounting slot is connected to a rotating plate 32 at the front and back via a rotating shaft. One end of each rotating plate 32 is detachably connected to an adjustable support member 33. Each rotating plate 32 has a magnetic sticker on its front wall.

[0021] The adjustable support 33 comprises a support seat 331, a threaded rod 332 and a knob 333, the support seat 331 is threadedly connected with the threaded rod 332, and the threaded rod 332 is threadedly connected with the knob 333.

[0022] The support table 4 is provided with a maintenance door 17 on one side.

[0023] Pressure sensors are arranged on the inner walls of the supporting ring A10, the supporting ring B8, the supporting ring C9 and the small telescopic air cylinder 11, and the pressure sensors are connected with a controller.

[0024] Embodiment 2

[0025] Specific operation of the present application: First, the preparatory stage of replacement is carried out: stop the dryer driving motor, the steam heating system, close the dryer inlet valve, the drain valve, ensure that the dryer completely stops running (need to wait for the dryer temperature to drop to 50 DEG C below, prevent high temperature scald or shaft head material deformation); Then, warning signs, protective fences are set in the operation area, and surrounding sundries are cleaned; the operation personnel wear safety helmets, anti-throw gloves and anti-skid shoes; Then, the residual steam and condensed water in the dryer are completely emptied, and the pressure in the dryer is confirmed to be 0MPa through the pressure gauge, so as to avoid steam leakage during disassembly.

[0026] After everything is ready, the special equipment is pushed to the front side of the dryer where the shaft head is to be replaced, and in the pushing process, the two supporting rings A10 on the upper side of the hydraulic cylinder A5 pass through the shaft head until the supporting ring A10 connected with the telescopic end of the hydraulic cylinder A5 is located opposite to the bottom of the shaft head, then the oil pump 13 is started, and the control valve 16 corresponding to each hydraulic cylinder at the lower part is opened, wherein the control valve 16 controls the oil inlet amount, so as to make the pushing processes of each hydraulic cylinder different, when the supporting ring connected with the telescopic end of each hydraulic cylinder contacts the inner wall of the shaft head and generates a certain pressure, the pressure sensor transmits a signal to the controller, the controller controls the opening and closing of each control valve 16, so as to make it close and stop the operation of the hydraulic cylinder.

[0027] Then, the small telescopic air cylinder 11 is started, so as to drive the supporting ring A10 on the upper part to move downward until the supporting ring A10 contacts the outer wall of the shaft head and generates a certain pressure, then the pressure sensor transmits a signal to the controller, so as to make the controller control the small telescopic air cylinder 11 to stop.

[0028] The rotating plate 32 beside the movable supporting bin 3 is rotated, the threaded rod 332 is threadedly installed at one end of the rotating plate 32, the support seat 331 is threadedly connected with one side of the threaded rod 332, and the knob 333 is threadedly connected with the other side of the threaded rod 332, after the installation is completed, the knob 333 is rotated again, so that the support seat 331 contacts the ground, and the whole device is stably supported on the ground, so as to prevent large displacement during disassembly.

[0029] Through the cooperation of the staff and the external tool, the dryer shaft head 2 is detached from the dryer shaft head mounting base 1, after the disassembly is completed, the adjustable support 33 is disassembled, the rotating plate 32 is turned back to the inside of the movable support bin 3 and is connected through magnetic attraction, through the external traction rope or other traction device, the whole special auxiliary equipment together with the drying shaft head 2 is transferred through the traction rod 31, and through another special equipment, the new shaft head is replaced, the whole replacement process does not need to lift the whole dryer, the safety of the staff is guaranteed, the replacement efficiency is improved, after the replacement is completed, the new shaft head and the dryer are debugged accordingly.

[0030] The basic principles and main features of the present application are shown and described above, and the advantages of the present application are shown and described above. The various components mentioned in the present application are common techniques in the prior art, and those skilled in the art should understand that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for online replacement of the shaft head of a drying cylinder in a paper mill, characterized in that... Includes the following steps: Step 1: Power off and safely isolate the equipment; Step 2: Use specialized auxiliary equipment for the drying cylinder shaft head to provide auxiliary support; Step 3: Replacement of the new shaft head; Step 4: Testing and debugging.

2. The method for online replacement of the drying cylinder shaft head in a paper mill according to claim 1, characterized in that... The specific steps of step one include: 1) Shutdown and power disconnection: Stop the drying cylinder drive motor and steam heating system, close the drying cylinder steam inlet valve and drain valve to ensure that the drying cylinder stops running completely; 2) Safety protection: Set up warning signs and protective fences in the work area, and clear away surrounding debris; workers should wear safety helmets, protective gloves, and non-slip shoes; 3) Medium evacuation: Thoroughly evacuate the residual steam and condensate from the drying cylinder. Confirm the pressure inside the drying cylinder is 0 MPa using a pressure gauge to prevent steam leakage during disassembly.

3. The method for online replacement of the drying cylinder shaft head in a paper mill according to claim 1, characterized in that... The auxiliary equipment for the drying cylinder shaft head in step two includes a movable support chamber, a support platform fixedly connected inside the movable support chamber, and a hydraulic support mechanism connected to the support platform. The hydraulic support mechanism includes hydraulic cylinder A, hydraulic cylinder B, hydraulic cylinder C, support ring B, support ring C, support ring A, and a small telescopic cylinder. Hydraulic cylinders A, B, and C are fixedly mounted in a straight line on the support platform. The telescopic end of hydraulic cylinder A is fixedly connected to support ring A. Small telescopic cylinders are fixedly connected to the left and right sides of support ring A. The telescopic end of each small telescopic cylinder is connected to another support ring A. The telescopic end of hydraulic cylinder B is fixedly connected to support ring B. The telescopic end of hydraulic cylinder C is fixedly connected to support ring C. The bottoms of hydraulic cylinders A, B, and C are all connected to the main oil supply pipe via branch pipes and control valves. The main oil supply pipe is connected to the oil tank via an oil pump. Pressure sensors are installed on the inner walls of support rings A, B, and C, as well as the small telescopic cylinders. The pressure sensors are externally connected to a controller.

4. The method for online replacement of the drying cylinder shaft head in a paper mill according to claim 1, characterized in that... The specific steps in step four include: 1) Static testing: Radial runout testing, end face runout testing, and sealing performance testing are performed on the replaced drying cylinder; 2) Dynamic debugging: Perform no-load test run and load test run on the replaced drying cylinder.

5. A method for online replacement of the drying cylinder shaft head in a paper mill according to claim 3, characterized in that... The movable support compartment is equipped with braked wheels at the four corners of its bottom. A traction rod is fixedly connected to the front wall of the movable support compartment. Installation slots are opened on the left and right sides of the movable support compartment. Each installation slot is connected to a rotating plate through a rotating shaft at the front and back. One end of each rotating plate is detachably connected to an adjustable support component. A magnet is provided on the front wall of each rotating plate.

6. A method for online replacement of the drying cylinder shaft head in a paper mill according to claim 5, characterized in that... The adjustable support includes a support base, a threaded rod, and a knob. The support base is threadedly connected to the threaded rod, and the threaded rod is threadedly connected to the knob.

7. A method for online replacement of the drying cylinder shaft head in a paper mill according to claim 3, characterized in that... An inspection door is provided on one side of the support platform.

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