Saturday, June 05, 2010
Self-anchoring, insertable plugs for pipes (helping BP)
I had a good time laughing at the thousands of seemingly uniformly inane suggestions pouring into BP about how to plug the leak. Then last night I came up with a few myself, which I've sent in. Here they are:
Plugging a heavily leaking undersea pipe by insertion is extremely difficult due to the high flow rate, which will strongly tend to push out any plug.
I am proposing three relatively simple and I believe novel devices, all of which are insertable plugs that redirect the flow pressure to anchor the plug against the inner wall of the pipe (as does, for example, a ventricular valve in the heart, when it is sealed against backflow.) In other words these plugs are designed to be “self anchoring” within the pipe, “using the pressure of the wellhead to seal the wellhead.” As with a ventricular valve in the heart, the greater the pressure, the firmer the seal (and anchoring) against the inner surface of the pipe, the reverse of what is the case with most plug designs that can be imagined. The length of these plugs can be varied - also graduated elasticity of the material employed - in order to distribute the flow pressure at the plug over a large enough area to maintain the structural integrity of the pipe.
Here the “top” or “top rim” of a plug is always the portion that is furthest up into the pipe, and the “bottom” of a plug is that part closest to the operator, and to the ocean water.
The first “can and cone plug” design is a quite simple hollow steel (or plastic), somewhat cup-shaped plug with a concave conical bottom. Imagine a simple hollow conical shape joined at its base to a hollow cylindrical sleeve of equal radius and more or less equal height. The cone tip points up toward the top (open) rim of the cup, away from the operator and toward the source of the current. (As is the case for a closed ventricular valve resisting backflow.) The radius of the plug is slightly smaller than that of the inside wall of the pipe.
This plug is inserted into the pipe open (top) rim first, with the base of the cone at the “bottom” of the plug (closest to the operator.) However: this may be most difficult design to insert, against pressure.
So long as the materials used in the manufacture of the plug allow some elasticity, and some compression (as well as significant tensile and compressive strength) the great force of flow/fluid pressure in the pipe will constantly force the plug to widen somewhat and thus be a more effective plug, which is even more tightly self-anchored to the walls of the pipe. It is, likely, important to distribute that force against to pipe to more than just a narrow ring however, to ensure the pipe does not burst – the length of the cylinder/outer sleeve helps accomplish this.
The cylindrical sleeve could go at either the top or bottom of the cylinder. If the top of the cylinder is joined to the bottom of the cone, insertion is eased but the pressure, principally transferred to the pipe around a narrow rim at the cones base, may breach the pipe, the initial anchoring may be more difficult to achieve, and variations in wellhead pressure may more likely to dislodge it.
Therefore, it is likely better to join the bottom of the cone to the bottom of the sleeve, so that they overlap forming a shorter device. The idea here is not to make the plug more compact, necessarily but to allow elasticity in the sleeve to distribute the pressure along a larger area of the inner surface of the pipe so that the pipe remains strucurally intact. This plug should be braced at its outer bottom rim only against the flow pressure within the pipe to deploy it – while inserting it, the center of force could be applied to the center/tip of the cone to prevent it from expanding prematurely.
A small area of concave flange (a small inverted cone section) at the top rim of the plug, farthest from the cone may help to anchor the top rim of this plug by using the flow pressure to force the top rim of the cylinder against the inner wall of the pipe. However, some means of obscuring the top flange during insertion would then be necessary to prevent its premature expansion.
Varying the plug's cylindrical wall thickness so that the area nearest the cone is less elastic may also help secure the seal along the “top” part of the plug so that the pressure against the pipe wall is well distributed. An abrasive or ridged (with slanted ridges) outer cylindrical surface of the plug may help prevent it from sliding, particularly if variations in pressure are likely.
This “can and cone plug” design can be a partial plug, or if you prefer, porous plug – with mesh or holes in the cone only slowing the flow. In this way a series of such plugs could be inserted (if flow pressure made insertion very difficult) to first slow that flow. Or, a series of such partial plugs could make up one long device in order to distribute the pressure over a larger length and area of the pipe to avoid overloading it.
The second “ring and torroidal bag” design is more easily inserted and deployed. Once the ring has been inserted, with the doughnut-shaped bag trailing, the bag is inflated with water or heavier fluid, to at least substantially reduce flow and at the same time anchor this plug against the wall of the pipe by leveraging the pressure of the flow within the pipe to force it's now triangular cross-section against the pipe wall. A second, longer, but similar device may then be able to seal it off.
The third “top-rim-anchored parachute” design would be least likely to breach the pipe, but requires a little more sophisticated design. It inserts a long “tube sock” into the pipe, but needs a rigid top rim that is a section of cone, or instead, a “ring and torroidal bag” partial plug could anchor it at the top, particularly until the cloth parachute plug is deployed.
The principle idea here is that it is necessary to insert a mechanical device that will redirect (exploit rather than merely attempt to directly oppose) the force of the flow along the pipe and transferring this force against the inner surface of the pipe, but at an angle to the force of flow that actually opposes the direction of the force of flow (or if you prefer, fluid pressure.) This is what the (conically shaped when shut) triangular ventricular valves within our heart and veins already accomplish – more blood pressure, as backflow, against these valves simply seals them tighter. This design of nature redirects the pressure of the fluid flow (in this case unwanted backflow) outward to the walls of the vein or artery and at an angle (vector) somewhat opposing the original force/backflow of blood which was “trying to go the wrong way”; this pressure is thus exploited or leveraged to both close the valve and seal it the more tightly against that very flow.
If you know a better idea, you can send it in to:
http://www.horizonedocs.com/artform.php
Plugging a heavily leaking undersea pipe by insertion is extremely difficult due to the high flow rate, which will strongly tend to push out any plug.
I am proposing three relatively simple and I believe novel devices, all of which are insertable plugs that redirect the flow pressure to anchor the plug against the inner wall of the pipe (as does, for example, a ventricular valve in the heart, when it is sealed against backflow.) In other words these plugs are designed to be “self anchoring” within the pipe, “using the pressure of the wellhead to seal the wellhead.” As with a ventricular valve in the heart, the greater the pressure, the firmer the seal (and anchoring) against the inner surface of the pipe, the reverse of what is the case with most plug designs that can be imagined. The length of these plugs can be varied - also graduated elasticity of the material employed - in order to distribute the flow pressure at the plug over a large enough area to maintain the structural integrity of the pipe.
Here the “top” or “top rim” of a plug is always the portion that is furthest up into the pipe, and the “bottom” of a plug is that part closest to the operator, and to the ocean water.
The first “can and cone plug” design is a quite simple hollow steel (or plastic), somewhat cup-shaped plug with a concave conical bottom. Imagine a simple hollow conical shape joined at its base to a hollow cylindrical sleeve of equal radius and more or less equal height. The cone tip points up toward the top (open) rim of the cup, away from the operator and toward the source of the current. (As is the case for a closed ventricular valve resisting backflow.) The radius of the plug is slightly smaller than that of the inside wall of the pipe.
This plug is inserted into the pipe open (top) rim first, with the base of the cone at the “bottom” of the plug (closest to the operator.) However: this may be most difficult design to insert, against pressure.
So long as the materials used in the manufacture of the plug allow some elasticity, and some compression (as well as significant tensile and compressive strength) the great force of flow/fluid pressure in the pipe will constantly force the plug to widen somewhat and thus be a more effective plug, which is even more tightly self-anchored to the walls of the pipe. It is, likely, important to distribute that force against to pipe to more than just a narrow ring however, to ensure the pipe does not burst – the length of the cylinder/outer sleeve helps accomplish this.
The cylindrical sleeve could go at either the top or bottom of the cylinder. If the top of the cylinder is joined to the bottom of the cone, insertion is eased but the pressure, principally transferred to the pipe around a narrow rim at the cones base, may breach the pipe, the initial anchoring may be more difficult to achieve, and variations in wellhead pressure may more likely to dislodge it.
Therefore, it is likely better to join the bottom of the cone to the bottom of the sleeve, so that they overlap forming a shorter device. The idea here is not to make the plug more compact, necessarily but to allow elasticity in the sleeve to distribute the pressure along a larger area of the inner surface of the pipe so that the pipe remains strucurally intact. This plug should be braced at its outer bottom rim only against the flow pressure within the pipe to deploy it – while inserting it, the center of force could be applied to the center/tip of the cone to prevent it from expanding prematurely.
A small area of concave flange (a small inverted cone section) at the top rim of the plug, farthest from the cone may help to anchor the top rim of this plug by using the flow pressure to force the top rim of the cylinder against the inner wall of the pipe. However, some means of obscuring the top flange during insertion would then be necessary to prevent its premature expansion.
Varying the plug's cylindrical wall thickness so that the area nearest the cone is less elastic may also help secure the seal along the “top” part of the plug so that the pressure against the pipe wall is well distributed. An abrasive or ridged (with slanted ridges) outer cylindrical surface of the plug may help prevent it from sliding, particularly if variations in pressure are likely.
This “can and cone plug” design can be a partial plug, or if you prefer, porous plug – with mesh or holes in the cone only slowing the flow. In this way a series of such plugs could be inserted (if flow pressure made insertion very difficult) to first slow that flow. Or, a series of such partial plugs could make up one long device in order to distribute the pressure over a larger length and area of the pipe to avoid overloading it.
The second “ring and torroidal bag” design is more easily inserted and deployed. Once the ring has been inserted, with the doughnut-shaped bag trailing, the bag is inflated with water or heavier fluid, to at least substantially reduce flow and at the same time anchor this plug against the wall of the pipe by leveraging the pressure of the flow within the pipe to force it's now triangular cross-section against the pipe wall. A second, longer, but similar device may then be able to seal it off.
The third “top-rim-anchored parachute” design would be least likely to breach the pipe, but requires a little more sophisticated design. It inserts a long “tube sock” into the pipe, but needs a rigid top rim that is a section of cone, or instead, a “ring and torroidal bag” partial plug could anchor it at the top, particularly until the cloth parachute plug is deployed.
The principle idea here is that it is necessary to insert a mechanical device that will redirect (exploit rather than merely attempt to directly oppose) the force of the flow along the pipe and transferring this force against the inner surface of the pipe, but at an angle to the force of flow that actually opposes the direction of the force of flow (or if you prefer, fluid pressure.) This is what the (conically shaped when shut) triangular ventricular valves within our heart and veins already accomplish – more blood pressure, as backflow, against these valves simply seals them tighter. This design of nature redirects the pressure of the fluid flow (in this case unwanted backflow) outward to the walls of the vein or artery and at an angle (vector) somewhat opposing the original force/backflow of blood which was “trying to go the wrong way”; this pressure is thus exploited or leveraged to both close the valve and seal it the more tightly against that very flow.
If you know a better idea, you can send it in to:
http://www.horizonedocs.com/artform.php
