Summary of installation technology of the hottest

2022-07-27
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Summary of installation technology of 5600mm paper machine (Continued)

2.5 installation of headbox 2.5.1 installation technical standard of headbox of our company this headbox is an air cushion headbox, and the installation technical indicators of headbox mainly refer to the levelness and parallelism tolerance of lower lip

the levelness and parallelism tolerance of the lower lip of our common headbox are both 0.02mm/m

2.5.2 installation procedure of headbox our company

(1) the headbox weighs as much as 43T (excluding the base), and its center of gravity shifts to the part (top heavy and bottom light). For the sake of reliability, we have made special treatment for the installation of the bottom rail of the headbox, that is, we have changed the anchor bolts into special studs, punched the floor slab at the reserved holes of the original anchor bolts, and placed a piece at the bottom of the girder δ= 30mm thick steel plate, use stud bolts to lock the steel plate at the bottom of the bottom rail and girder, and tighten the nuts to firmly fix the headbox bottom rail. In order to prevent the bolts and steel plates from rusting, the studs and steel plates below the floor and around the girder are poured with concrete to make them connected with the girder and not exposed to the air (see Figure 4)

(2) locate and align the headbox support according to the equipment installation drawing and equipment structure drawing, and then put the headbox in place

(3) considering that the overall length of the headbox is nearly 7m, the change of temperature difference will cause thermal expansion and cold contraction of the headbox. This should be taken into account before installing the headbox. To this end, the following measures have been taken

since the headbox is connected with the four legs on its base by bolts, the tightening torque of the connecting bolts on the drive side is 600N · m, and the joint surface should be clean and free of oil stains to ensure that it will not shift due to thermal expansion and cold contraction; The connecting bolts of the other three legs shall be tightened with a torque of 200N · m, and the joint surface shall be clean and coated with lubricating oil, so that the headbox can move to the operating side when it is expanded and shrunk

the levelness and parallelism correction of our (4) lower lip is the key point of headbox installation. Due to the high requirements for levelness and parallelism, laser theodolite is used for detection. The laser theodolite shall scan and test the panel of the lower lip plate, and the difference of the test value shall be within the allowable range. After the levelness is calibrated, measure the parallelism of the lower lip, set the ruler horizontally on the lower lip, measure the values of the operating side and the transmission side, and ensure that the values are within the tolerance range

2.6 installation of our department

2.6.1 installation technical standard of our department

levelness tolerance of our roller: 0.02 ~ 0.03mm/m

parallelism tolerance of our roller: 0.03mm/m

24h Cantilever Test of our cantilever beam; The reduction of the space between the suspended positions at the operating end shall not be greater than 20mm

2.6.2 installation steps of our department

our company (1) positions according to the marking on the bottom rail surface, first install the vacuum couch roll, and use the theodolite to calibrate the levelness and parallelism of the couch roll

our company (2) installs and aligns the C-beam (cantilever beam), longitudinal beam and support, and screw the connecting bolts as required

our company (3) put the chest roll in place, and then correct the levelness and parallelism of the chest roll. It is required that the levelness tolerance of the chest roll is within 0.02mm/m and the parallelism tolerance is within 0.03mm/m

our company (4) is in place and aligned to lower each drive roll, tension roll, correction roll and guide roll

our company (5) installs and aligns the brackets on both sides and the Whitewater tray on the

our company (6) installs and aligns each drive roll, tension roll, correction roll and guide roll

our company (7) has made great achievements in positioning, including shape board, chopping board, arc chopping board and vacuum dewatering tank, and adjusted the spacing. Hang a piano line from the chest roll surface to the drive roll surface at the operation side and the drive side, and hang a heavy hammer at both ends of the piano line to straighten the piano line. Take the piano line as the reference line to adjust the planes of the forming board, cutting board, arc cutting board and vacuum water suction tank to ensure that their plates are on the same plane

2.6.3 after the installation and adjustment of the bracket, roller, tension and correction device, scraper, spray pipe, etc. of the cantilever beam (C-beam) of our company, a strict cantilever test must be carried out on the cantilever beam (its price is relatively expensive, see Figure 5) to check whether the civil foundation meets the requirements of other standards and whether the equipment installation meets the requirements. The specific test steps are as follows:

(1) tighten the connecting bolts on the transmission side of the cantilever beam

(2) loosen the connecting bolt on the operating side of the cantilever beam, put down the bolt, and measure the value of H

(3) jack up the cantilever beam at the operating side and pull out the movable support

(4) the jack shall be relieved and removed to make the cantilever beam in cantilever state

(5) measure the H ′ value after 24h of cantilever

statement:

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