DE19636488C1 - Protective cladding for channels - Google Patents

Abstract

To clad a channel with a film, for protection against corrosion, the film webs (5,6) are laid on the inner surfaces (3) of the channel, with overlapping film (5,6) edges. The film webs (5,6) are secured at points by mounting bolts (7') passed through the channel wall (1). At least one retainer is fitted at the inner end (23) of the mounting bolts (7') towards the channel interior, at the overlaps between the film webs (5,6), to press them flat together, and the webs 95,6) are welded together at the overlaps. The retainer is removed, and the inner ends (23) of the bolts (7') are covered with a gas-tight cladding. The film can be of perfluor-alkoxy copolymer.

Description

The invention relates on the one hand to a method for clothing of the inner surfaces of a gas Channel with a corrosion protection film and on the other an arrangement for fixing overlap on the edge donate film webs on the inner surfaces of the channel Undress.

In the present case, channels are used for channel, chamber or housing like flow areas as at least indirect loading components of heat exchangers in highly corrosive processes designated.  

When operating systems, for example for preheating of combustion air in power plants or for heat recovery in waste incineration and industrial plants, ent are hot and aggressive gases with highly corrosive loading share. The channels through which the gases flow or the steel walls of these flow areas the adverse effects of the aggressive gases protect, it is known to use the inner surfaces of the channels a corrosion and temperature resistant plastic film to undress.

The anti-corrosion films must be attached to the walls be, the fastenings various operational conditions exposed to stress. The fortifications must on the weight of the horizontal and vertical walls of the flow areas laid Korro sion protection films. They also have to can absorb and derive gas-side negative pressure. In addition, the fastenings are permanently changeable stresses from the pressure and / or temperature changes exposed to, especially in the arrival and / or Make shutdown operation noticeable. It is also very important that the fastenings are gas-tight.

In this context, one type of fastening is included State of the art, in which corrosion protection film un ter using the pin pushing technique with pin-shaped Fastening bolts on the inner surface of the duct wall is nailed. The mounting bolts are by the Fo lie and the channel wall driven, then usually lie using a washer against the film and chipping these with the channel wall. This kind of punctual Fixation of the corrosion protection film has in the Proven in practice.  

Especially when lining larger duct or housing-like flow areas must have multiple foils Sections assembled in strips and into a closed a tight lining. A common one The procedure is to use comparatively narrow fo railways with a width of, for example, 1.20 m to lay the inner surfaces of the channel walls. After this First fix two sheets of film that are in contact with each other overlap a certain amount, these will along the longitudinal edge of the overlapping film web with the Ver. Outer surface of the film below welds. The lining is then each by Anset zen another film web continued.

To ensure the highest possible weld quality, must have relative movements of the film webs to be connected can be prevented during the entire welding time. At the Welding process is therefore necessary for at least two people manoeuvrable, one that carries out the welding process and another person holding the overlapping film web presses flat against the lower film web so that the Welding process can be carried out.

This approach is comparatively labor and time consuming. The people in the partially cramped conditions of a construction site also ge mutual, so that the quality of the weld suffer can.

DE 1 95 04 442 A1 includes an arrangement Fixation of a corrosion protection film on a steel State of the art wall of a gas duct. The order includes a bolt made of polytetrafluoroethylene. Of the Bolt has a circular flange as well a one-piece threaded pin. The flange of the Bolt is made with the help of a steel pad washer and a steel nut on the inner surface the channel wall fixed. For fixing the corrosion protective film made of perfluoro-alkoxy copolymer on the face surface of the flange, a welding machine and a Adapter film, which is also made of polytetrafluoroethylene consists. The one is affected by pressure and heat lower melting point plastic of the Korro sion protection film melted and in this way the Cor Anti-corrosion film with the flange and the adapter film connected over a large area.

Resin is also part of the technological background impregnated lining in pipes according to EP 0 149 845 A2. This lining is used on resin-absorbent kis attached inside the pipes.

The invention is based on the prior art Task based on a process for lining the In surfaces of a duct to which gas can be applied a corrosion protection film easier and more efficient design, the overall lining both ago more favorable in terms of position and operation becomes. The invention further aims at an arrangement  for fixing the overlapping foils on the edge pave the way, which is a rational, fast and operational safe installation of a high quality lining allowed.

The procedural part of this task is fiction according to solved by a method according to claim 1. The Lö The objective part of the task is described in the Features of claim 3 seen.

The inventive method, as in claim 1 cha is initially characterized, the film webs on the inner surfaces of the housing walls under the edge Overlapping of the Fo arranged next to each other Lienbahnen to lay loose.

This is followed by the fixation of the film webs several points. This is done by setting fastening bolts penetrating the film webs the canal wall. The number of mounting bolts and the Distance between these is dependent on the Be drive data selected.

The be particularly advantageous for fixation Known bolt push technology for use. The bolt push is positioned and ge against the film presses. By triggering a defined propellant charge in the Bolt pusher is then a mounting bolt from the Device pressed out with high energy and through the film pushed into the base material of the channel wall. The boost path is defined so that an impermissible Violation of the corrosion protection film is avoided. In addition, the fastening bolt is a pressure pane assigned to damage the film when Prevent driving in the fastening bolt.  

Of course, other purposes are also fulfilling Fixing techniques of the fastening bolts possible.

At the inner ends of the feet facing the canal a hold-down pin is then fixed. Of the Hold-down serves to overlap the Fo lienbahnen to press flat against each other.

Basically, it is possible to be between two neighboring fastening bolts a hold-down affiliate. This can also be link-like in length be built up so that an adaptation to possible bumps units of the inner surfaces of the channel is possible. The never the holder can also extend in its longitudinal direction extends over several fastening bolts.

After the hold-down is locked and the overlap areas of the film webs are fixed in a position-oriented manner, the foil webs are ver in the overlap areas welds. The welding is expediently carried out along the longitudinal edge of the overlapping film web the outer surface of the film below.

Within the scope of the invention it is also possible to use the Ver welding of the foil webs not exactly along the Long edge of the overlapping film web, but further inward in the overlap area. This is for example the use of a welding wheel is conceivable, which is guided over the film webs and this with welded to each other.

After welding and removal of the Hold downs are the inner ends of the attachment bolt covered gas-tight. This is done through art fabric hoods that are placed over the ends or put on  and welded to the underlying film web will.

In a particularly advantageous development of the general my inventive idea is vorese according to claim 2 hen, plastic caps on the threaded in to screw or close the other ends of the fastening bolts beat. The plastic caps are then edged ver gas-tight with the overlapping foil welds. The welding can be done manually as well mechanically, for example by means of a heating element welding or inductive welding will. Effective corrosion protection of the Be fastening bolts and a tight lining guarantee continuous

The entire lining is self-contained and ge ensures reliable use even with under pressure. Another advantage is their rational production position to see.

Essential feature of the arrangement for fixing itself edge overlapping film webs is according to claim 3 a hold-down device that overlaps the film webs richly presses together so that the radial movement against the foil webs during the welding process the.

The hold-down device is in the direction of the channel Neren ends of the fastening bolts can be fixed. The feast Laying can basically be done in different ways non-positively and / or positively, for example by clamping, exciting or by screwing.

A fastening bolt thus has several functions assigned. On the one hand it serves to fix the  Foil sheets on the canal wall. Furthermore, his ka inner end directed inward as an anchor point for the hold-down device. Finally, he can go to the fixie a cover cap can be used.

Depending on the training and condition of the The hold-down device to be lined can be shorter or longer and possibly also limited articulated under shares be trained. This can cause possible bumps units of the wall. The hold-down can therefore be one or more layers.

Overall, it is possible in this way, first of all the entire height of a channel, the two of them together other foil webs to be connected in the overlap area to be defined exactly. Then the weld seam can then can be easily placed.

A particularly advantageous embodiment of the inventions arrangement according to the invention is in the features of the claim 4 characterized. Thereafter the hold-down comprises at least at least one spacer, one pressure bar and one Terminal block.

The spacer points to the contour of the pressure disc of a mounting bolt adapted recess on. So the spacer around the pressure plate Fastening bolt are placed. Between two distances pieces the pressure bar is integrated and by means of a terminal block fixed in position. The terminal strip becomes this clamped at the inner end of the fastening bolt. With With the help of a terminal strip, each can be combined into one Fastening bolts adjacent pressure strips be fixed.  

An angle is particularly suitable as a pressure bar profile. Here, the protruding from the film webs Legs are used to guide the welding machine.

According to the features of claim 5 is the hold-down by means of a clamping bolt on the inner end of a fastening fixable bolt.

To do this, the clamping bolt can be placed on the inner end of a Befe be screwed on. With the help of one an external thread of the displaceable nut can then hold down the clamp or the terminal block will.

The arrangement according to the invention thus allows a ratio Fast and reliable installation of a qualita tiv high quality lining. Relative movements of the Fo Lines during the welding process are avoided, so that a perfect welding of the film webs can be taken.

The invention is described below with reference to FIGS. 1 to 7, in which the procedure for lining a channel wall with corrosion protection film / and the arrangement according to the invention used for fixing the film webs is described using an exemplary embodiment.

Show it:

Fig. 1 in vertical cross section a section of a flue gas duct with applied
Foil sheets and fastening bolts;

Fig. 2 shows the representation of Figure 1 in plan view.

Fig. 3 also in vertical cross section the Dar position of Figure 1 with a distance piece of a hold-down according to the invention;

Fig. 4 shows the representation of Figure 3 in plan view.

5 shows in vertical cross section the display of Figure 1 in a next step with position-fixed pressing and clamping bar..;

Fig. 6 shows the representation of Fig. 5 in plan view and

Fig. 7 shows the representation of Fig. 1 after completion of the welding.

1 1, a portion of a steel wall is shown in FIGS. To 7 designates which forms a flue gas channel 2 with further non-illustrated walls. To protect the walls 1 , the inner surfaces 3 of the smoke gas duct 2 are coated with a corrosion protection film 4 .

For this purpose, film webs 5 , 6 are initially loosely laid on the inner surface 3 . In this case, the film webs 5 , 6 overlap at the edges.

The attached foil webs 5 , 6 on the channel wall 1 is done by means of fastening bolts 7 , 7 'made of steel, which are driven by means of a bolt pusher from the inside 8 in the overlap area 9 through the foils 5 , 6 into the channel wall 1 . In the illustrated embodiment, the overlap dimension Ü is at least 50 mm. The distance A between two fastening bolts 7 , 7 'is dependent on the operating data ( Fig. 2).

A fastening bolt 7 , 7 'has a smooth length section 10 and a threaded section 12 provided with an external thread 11 . Between the tread formed thread section 12 and the overlap the film web 6 is a pressure plate 13 made of fluorine plastic and a metal pressure plate 14 is divided. To protect the film web 6 , the pressure disk 13 acting on it is selected from plastic and has a relatively large diameter. The metallic pressure plate 14 ensures a distribution of the pressure force.

The length section 10 of the fastening bolt 7 , 7 'is driven with its tip 15 under deformation of metal mass through the channel wall 1 . This results in a tight fit of the fastening bolt 7 , 7 'in the channel wall 1 and thus also a firm support of the film webs 5 , 6 on the inner surface 3 of the channel wall 1st

3 and 4 as is apparent from the Fig., Distance pieces 16 are about the fastening bolt 7, 7 'and set the pressure plates 13, 14. For this purpose, the spacers 16 have a recess 17 adapted to the contour of the pressure plates 13 , 14 .

A pressure bar 18 is incorporated between the spacers 16 and fixed in position with a clamping bar 19 (FIGS . 5 and 6).

The spacers 16 , the pressure bar 18 and the clamping bar 19 together form a hold-down 20th The never derhalter 20 ensures that the film webs 5 , 6 are pressed flat against each other in the overlap area 9 , so that a perfect welding along the longitudinal edge 21 of the overlapping film web 6 with the outer surface 22 of the underlying film web 5 .

As can be seen in FIGS. 5 and 6, the clamping strip 19 is of the fastening bolt 7 set of the blank holder 20 on the kanaleinwärts ge directed inner end 23 '. This is done by means of a clamping bolt 24 which is guided through a through opening 25 in the terminal block 19 . At its lower end 26 , the clamping bolt 24 has a bore 28 which has an internal thread 27 . So the bolt 24 can be screwed to the threaded section 12 of the fastening bolt 7 '.

With the help of a nut 29 , which is displaceable on the external thread 30 of the clamping bolt 24 , the terminal block 19 is clamped while simultaneously fixing the pressure bar 18 with the fastening bolt 7 '. This results in a flawless surface adaptation of the longitudinal edge 21 to be welded with the film web 5 underneath.

After completion of the weld 31 , the hold-down 20 is removed and the inner ends 23 of the fastening bolts 7 , 7 'covered gas-tight.

As shown in FIG. 7, a plastic cap 32 is used for this. This is screwed onto the threaded section 12 of the fastening bolts 7 , 7 'and welded gas-tight at the edge to the overlapping film web 6 .

Reference list

1 wall
2 flue gas duct
3 inner surface
4 corrosion protection film
5 film web
6 foil web
7 fastening bolts
7 ' mounting bolt
8 inside
9 overlap area
10 length section
11 external threads
12 threaded section
13 pressure plate
14 pressure plate
15 tip of 10th
16 spacer
17 recess
18 pressure bar
19 terminal block
20 hold-down devices
21 longitudinal edge of 6
22 outer surface of 5
23 inner end of 7 , 7 ′
24 clamping bolts
25 through opening in 19
26 lower end of 24th
27 internal thread
28 hole
29 mother
30 external threads
31 welding
32 plastic cap
A distance
Ü dimension of overlap

Claims (5)

1. A method for lining the inner surfaces ( 3 ) of a gas-loaded channel ( 2 ) with a corrosion protection film ( 4 ), with film webs ( 5 , 6 ) by fastening bolts ( 7 , 7 ') on the channel wall ( 1 ) and fixed then two adjacent film webs ( 5 , 6 ) are welded together, characterized by the following measures:

• a) Laying the film webs ( 5 , 6 ) on the Innenflä surfaces ( 3 ) with edge overlap of the film webs ( 5 , 6 ) arranged side by side;
• b) fixing the film webs ( 5 , 6 ) at several points by fixing the film webs ( 5 , 6 ) penetrating fastening bolts ( 7 , 7 ') on the channel wall ( 1 );
• c) Setting at least one hold-down device ( 20 ) on the channel-facing inner ends ( 23 ) of the fastening bolts ( 7 , 7 '), the hold-down device ( 20 ) pressing the overlapping areas of the foils ( 5 , 6 ) flat against one another;
• d) welding the film webs ( 5 , 6 ) in the overlap areas;
• e) Removing the hold-down device ( 20 ) and gas-tight covering the inner ends ( 23 ) of the fastening bolts ( 7 , 7 ').

2. The method according to claim 1, characterized in that plastic caps ( 32 ) on the threads ( 11 ) provided with inner ends ( 23 ) of the fastening bolts ( 7 , 7 ') and the plastic caps ( 32 ) are then edged with the respective overlapping film ( 6 ) welded gas-tight. 3. Arrangement for fixing edge overlap penden film webs ( 5 , 6 ) on the inner surfaces ( 3 ) of a gas can be acted upon channel ( 1 ), in the fastening bolt ( 7 , 7 ') the film webs ( 5 , 6 ) and the channel wall ( 1 ) penetrate with orientation of the foil webs ( 5 , 6 ), each fastening bolt ( 7 , 7 ') being assigned a pressure plate ( 13 , 14 ) and one of the overlap areas ( 9 ) of the foil webs ( 5 , 6 ) press against each other never derhalter ( 20 ) on the channel-facing inne ren ends ( 23 ) of the fastening bolts ( 7 , 7 ') can be fixed. 4. Arrangement according to claim 3, characterized in that the holding-down device ( 20 ) comprises at least one spacer ( 16 ) which can be placed around a fastening bolt ( 7 , 7 ') and which is adapted to the contour of the pressure plate ( 13 ' 14) from recess ( 17 ), and the hold-down device ( 20 ) also has an articulated pressure bar ( 18 ) between two spacers ( 16 ), which can be clamped by means of a clamping bar ( 7 , 7 ') clamped at the inner end ( 23 ) of the mounting bolt ( 7 , 7 ') 19 ) is held fixable. 5. Arrangement according to claim 3 or 4, characterized in that the holding-down device ( 20 ) can be fixed by means of a clamping bolt ( 24 ) at the inner end ( 23 ) of a fastening bolt ( 7 , 7 ').