Method and apparatus for injecting foam into a pipeline, including an inflatable plug

The invention relates to a device according to the preamble of claim 1 and to a method for operating this device.

It is planned to inject chemical agent to kill root growth in sewer or sewer pipes; these agents are preferably provided in the form of foam, which adheres firmly to the pipe wall as well as to obstacles such as tree roots and grease deposits within the sewer pipes. The foam known for this purpose has the effect of inhibiting the growth of, for example, tree roots and killing the roots within the sewers.

According to the US-PS 38 74 926 a device and to an operating method is already known, is injected with the or in the foam in a pipe by means of the hose of this device, at its end located in the pipeline an inflatable plug is firmly attached ,

This plug has in continuation of the hose a rigid passage for the already passed through the hose foam, in the form of a tube. Around this tube, the parts of the plug are firmly attached to this immovable. The air line for inflating the plug runs there in the tube and opens from the inside in the stopper.

This device has been proven in many cases, for. For example, in the treatment of sewers in homes and other buildings, but there are also conditions under which difficulties arise. If you wanted to treat a long pipe, / .. B. a sewer pipe between two manholes, and began with the injection of foam by the method and with the device of US-PS 38 74 926, so a back pressure developed, so that one could treat only a fairly short distance of a sewer or other pipeline , The back pressure had the effect that the foam penetrated into the connection lines and installations of buildings. In other words, as the injected foam exited the end of the tube, it was advanced by the pressure of the subsequent foam in the tubing, but after a short time, the ejected foam counteracted the subsequent foam with increasing resistance or back pressure. Soon the resistance was so strong that the subsequent foam was pushed up in branches and connections as well as through the sewers of houses into the installations of houses and other buildings.

A - as far as the invention still to be explained - the device described above

similar device is known from US-PS 30 75 535, in which also in continuation of the hose at the front end of an inflatable plug is firmly attached. Inside this plug L *, in turn, there is the passage for the foam already passed through the hose.

The invention has for its object to provide a device by means of which a length^rhe section of a pipeline can be processed at each treatment, without large additional pressures are required and in particular not substantially to the application for feeder lines, z. B. on the sewer pipes of buildings, is limited.

This object is achieved with a device according to the preamble of claim 1, which is characterized according to the invention by the features of the characterizing part of claim 1. Further embodiments and an operating method gehjn from the dependent claims.

The present invention enables the treatment of both mains and service lines connecting residential homes and other single users to the main sewer pipes. The invention also offers the advantage that the treatment of the deeper parts of such branches from the main lines is possible. By appropriate regulation of the foam pressure in the main line, a part of the foam can get into the connection lines, without it penetrating into the) <> apartments themselves. It has also been shown that in the main sewers often such a strong root growth i: t that the movement of the foam is hindered unu in the line an excessive foam pressure. By the invention it is made possible to push against the plug relatively thin foam delivery hose to beyond the root system, after the tube has already been filled with foam above the root system. Thus, the entire pipe section to be treated with foam can be filled with foam, without the need for high pressures, which would force the foam through the building connection pipes into the installations.

The device according to the invention is provided with an inflatable plug having a cylindrical through-channel with a flexible wall and, as known, a flexible outer wall surrounding the channel at a distance, the channel forming wall and the outer wall are connected by "> o two end walls, which thus form a chamber between the channel and the outer wall. One of the end walls has a Lufteii.laß, which leads into the chamber. The plug is known to be displaceable in the pipes to be cleaned, so that it can be easily inserted into the pipe and brought to the desired location without regard to whether it is a sewer pipe, a connection or any other Leiti'ng Thereafter, as is well known, the plug may be inflated to seal the conduit between the plug and the tube wall, in which respect the device is still similar to that disclosed in U.S. Patent No. 3,874,926. However, it differs from this in that the hose, which serves to introduce the foam, in the invention ^h5 is normally displaceable in the channel of the plug. The tube can therefore be inserted into the channel, pushed through the plug in any length and extend to any desired location. Then, the plug is inflated in place, so that it rests firmly against the outer wall, he holds in principle, the hose in the channel of the plug and prevents backflow. However, by properly controlling the air pressure in the chamber, it is possible to still slidably hold and move the hose relative to the plug while passing foam through the hose.

By means of this plug according to the invention, it is possible that the flexible hose through which the foam is passed extends beyond the plug in any adjustable length. For example, if one wishes to treat a pipe section between two manholes, one can arrange the outlet of the flexible hose approximately in the middle between these two points and the plug near the one point; the ejected foam will first continue to flow in the direction of the tube and then, as the pressure increases, flow back along the tube and around it; after that, it will alternately move in both directions under a pressure sufficient to drive the foam through the full length of the sewer section to be treated, without creating such great pressure that the foam is forced up into the house installations. One skilled in the art can vary the location of the ski outlet to control the pressure of the foam as needed, optionally during work and while injecting foam. This means that a significantly larger and longer pipe section can be treated than with the device according to US Pat. Nos. 3,874,926 and 3,075,535.

In the stated method of operation with the device according to the invention, the foam is produced, conveyed under pressure to the inlet of the flexible foam hose and passed through this hose to its outlet, while the pipeline to be treated, is shut off at a point located at a considerable distance from the outlet point of the hose , This distance can be changed easily.

In the method, the air pressure in the chamber can be controlled so that the plug is held in its position in the sewer line and the hose is thereby pulled through the plug. In some cases this is done while foam is being injected.

The device according to the invention can also be used for the treatment of connection lines by insertion into a siphon or a similar cleaning device of a house connection; in this case, the plug is inflated in the vicinity of the siphon to prevent backflow, and the flexible tube is inserted as far as desired in the relevant connecting line to eject the foam there so that it finally moves in both directions, but without to flow back through the siphon.

Embodiments of the invention are explained in more detail below with reference to schematic drawings. It shows

Figure 1 is a schematic, partially in section view of a device according to the invention for the treatment of a main sewer pipe between two manholes. the device is in its Betriebsstellune dareestellt. the stoning is the

Accumulates after-run of water while injecting foam at the bottom, which fills the tube and rises to a predetermined extent in the branch or connecting lines;

F i g. Figure 2 is an enlarged section through the plug shown in Figure 1;

F i g. 3 is a section along line 3-3 in FIG. 2;

Fig. 4 is an enlarged view of part of the apparatus of Fig. 1, with the flexible hose extending in the opposite direction from Fig. 1; the position of the plug in the inflated state is indicated by dashed lines;

F i g. Figure 5 is a schematic view of a device according to the invention inserted into the cleaning opening of a shower drain with a siphon to clean a connection line at the cleaning opening of a single user;

Fig. 6 is a representation similar to Figure 2 of an amended plug according to the invention.

F i g. 7 is a section along the line 7-7 in FIG. 6;

Fig. 8 is an even more enlarged view of a part of the device according to F i g. 5 using the plug after F i g. 6; and

9 is an enlarged section along the line 9-9 in Fig. 1st

In all embodiments of the invention, a flexible hose 10 is used which has sufficient strength and strength to remain upright and not buckle but which is flexible enough to bend around corners so as to be usable in pipelines of various types is. The size of the tube 10 depends essentially on the amount of foam it is to convey. It may contain a plastic or synthetic rubber hose which is insensitive to the chemical substances used. He may optionally be provided at its periphery with a gain in order to increase its rigidity.

The hose 10 has an inlet 11 and an outlet 12. The inlet 11 of the hose 10 is connected to a foam generator 13 which may be a suitable pump in which air and liquid are introduced. It can be a hose with a diameter of³Λ to I¹A inch should be used, which should preferably be transparent, so that the foam delivery can be monitored. Such a large amount of foam is produced and dispensed so quickly that also side branches or lines of the septic part of the plant of normal length can be filled within a few minutes. It is desirable to have a foam delivery of typically on the order of about 40 to about 300 liters per minute, which will be produced from about 4 to about 15 liters of the liquid mixture used. This mixture preferably contains 5% of a suitable foaming root-borne plant killer with a surfactant which serves to maintain the foam structure and to remove fat and mucus from the roots; the rest of 95% is water. Such a foam with its active ingredients, after being injected into a pipeline, adheres to the roots and the interior of the pipeline for some time, even when normal water flow has re-established, so that the roots are treated for a longer period of time and fat and other debris to improve absorption of the agent. The adhesive effect prolongs the duration of treatment and ensures an effective uptake of the roots' toxins contained in the chemical to provide complete kill and long-term control of new growth.

In the invention, the hose 10 is used in conjunction with the plug 15. The plug 15 has an inner wall 16, which has a continuous cylindrical

»Channel 17 forms. The tube 10 is guided into this channel 17 and through it. The tube 10 is slidable with respect to the wall 16, but with sufficient resistance to hold it in a selected position as the device is brought into its operating division. However, it is so easily displaceable that the length of the tube 10 extending beyond the plug 15 can be changed as desired until the plug 15 is inflated. Even then you can hold the plug 15 under such inflation pressure that, although it is held in place, but the hose 10 relative to the plug 15 can be moved.

The plug 15 further includes an outer wall 18 which may be reinforced by a cloth 19, preferably containing a number of longitudinal threads distributed around its circumference, so that an outward expansion can take place unhindered and yet provide reinforcement is available.

M) The wall 18 is connected to the wall 16 by rigid, annular end walls 20 and 21, and the four walls 16, 18, 20 and 21 enclose an annular chamber 22. The annular chamber 22 is completely closed, except for a small opening 23, which leads through the wall 20. In this air opening 23, an air supply hose 24 is attached, which extends outside of the hose 10. During use, the air hose 24 is replaced by an elongated air duct 25 with an air duct.

4 ') denser 26 connected, which generates compressed air and promotes them through the lines 25 and 24 in the chamber 22. With sufficient air pressure, the wall 18 expands, as in FIG. 1 and shown in FIG. 4 indicated by dashed lines, and comes into contact with a surrounding from the outside surface, for. As the wall 27 of the sewer pipe 28. The plug 15 therefore blocks this portion of the sewer pipe 28 and prevents passage of foam around the plug 15 around. At the same time, inflation of the plug causes the inner wall 16 to tightly encase the tube 10 and prevent any backflow of foam between the tube 10 and the wall 16, as well as mutual movement of the plug 15 and the tube 16

In operation, the hose 10 may be pulled through the plug 15 in any desired length, and the plug and hose are inserted together through a manhole 29 into the sewage pipe 28

w) The plug 15 is usually placed in the immediate vicinity of the manhole 29 while the outlet 12 of the hose 10 at a suitable location is z. B. the middle between the manhole 29 and a subsequent manhole 30. If the distance between the manholes 29 and 30 is very large, the outlet 12 can be arranged at about a quarter of the way, and later, the hose 10 through the manhole 29 pulled out and through the manhole

30 be reintroduced to treat the second half of the route between manholes 29 and 30.

When the plug is in place, air is introduced from the compressor 26 through the conduits 25 and 24 into the chamber 22 to inflate the plug 15 and closely abut the wall 18 against the tube wall 27 and the wall 16 at the To cause hose 10. The waste water 31 is thereby stowed in the sewage pipe 28 above the plug 15 and partially fills the manhole 29th

While the air pressure is maintained, foam is passed from the foam generator 13 through the tube 10 to the outlet 12 from which it emerges as foam 32. At the outlet 12, the foam initially tends to flow toward the manhole 30 until sufficient pressure builds up to cause backflow so that the foam flows back toward the plug 15 for a while. The flow fluctuates in accordance with the pressures until a final pressure is reached at which the tube is filled with foam 32 and a portion of the foam also enters the leads 33 and the manhole 30. Penetration into the leads 33 is controlled by controlling the injection pressure, and penetration of the foam 32 into the house and its installations is prevented.

After this treatment, the tube 10 can be withdrawn by letting the air out of the plug 15 and pulling the whole direction through the manhole 29. As already mentioned, the foam adheres internally so that retraction does not mean that the treatment has ended. To facilitate retraction, the plug 15 may include a wire eyelet 34 with an anchoring embedded in the end wall 20 and, during use, a chain or cable 35 may be secured to the eyelet 34. The cable or chain 35 may extend to the upper end of the manhole 29 and be held in its vicinity by a manhole cover located on its end 37. After emptying the plug 15, the chain or cable 35 and eyelet 34 are easier to remove.

The eyelet 34 and the cable or chain 35 may also, with special treatment, serve to hold the plug 15 in place while moving the hose 10 and changing the air pressure in the chamber 22 for that purpose

F i g. 5 shows the treatment of a connecting line with a device according to the invention. In this case, the plug is considerably smaller. F i g. Figure 4 shows a siphon 40 with a normal inlet 41 and additionally with a cleaning port 42 which is normally closed by a cap or plate not shown here. The siphon 40 leads to a connecting line 43, which opens into a main sewage pipe. For use of the device according to the invention, the plate has been removed and the plug and tubing have been inserted into the cleaning port 42. Here, a plug 50 together with the

κι hose 10 used. The connection of the hose 10 to a foam generator 13 is as described above, and a similar air compressor 26 to the air duct 25 may be used. A plug 50 can be used which exactly matches the plug 15, but in FIG. Figures 6 to 8 show a differently shaped plug for further explanation. In this case, the plug 50 has a cylindrical inner wall 51, a cylindrical outer wall 52 and annular end walls 53 and 54. The cylindrical inner wall 51 is thicker than the wall 16 and is provided with reinforcements, but here it surrounds a continuous channel 55 through which the tube 10 can be pushed into a desired position. The length of the tube extending through the plug 50 into the lead 43 may be regulated as desired. The walls of the plug 50 include a chamber 56, and an end wall 53 has an inlet 57 for introducing air into the chamber 56.

The reinforcement is preferably made of a

K) series of circumferentially arranged threads, so that an expansion to the outside is possible. In the stopper 50 described herein, a series of circumferential ribs 58 are also provided on the outside of the wall 52 to provide even better engagement with the tube 43. Further, an eyelet is attached to the end wall 53 and to the outer wall 52; for insertion or removal of the plug 50, a cable can be passed through the eyelet 59.

The operation of the device according to FIG. Figs. 5 to 8 are substantially as described above; the tube 10 is inserted into the plug 50 so as to extend beyond the desired length thereof, and the device is inserted into the tube 43 so that the plug 50 can be fixed in the tube 43 at a point which Preferably, the cleaning opening 42 is closely adjacent. Now, the plug 50 is inflated, and its wall 52 fits tightly against the wall of the tube 43, while the wall 51 firmly abuts against the wall of the tube 10. Foam is generated and directed into the tube 10 and tube 43 to treat it in the manner previously described. After completion of the work, the plug 50 is emptied and the device retracted.

For this 2 sheets of drawings