A seal for sealing against the interior of a tube includes upper and lower rigid plates with flexible plates between them, which are compressed to form a seal.
1. A seal for a tube having a projection coming out of the tube, comprising:
upper and lower rigid plates, each having a perimeter and defining first and second openings, wherein said first openings extend to the perimeter of their respective plates;
at least one flexible plate having a perimeter and defining first and second openings, wherein said first opening extends to the perimeter of the flexible plate, said flexible plate being sandwiched between the upper and lower rigid plates;
wherein said first openings of said upper and lower rigid plates and of said flexible plate are vertically aligned and said second openings of said upper and lower rigid plates and of said flexible plate are vertically aligned; and
wherein said upper and lower rigid plates have substantially the same diameter and said flexible plate has a diameter that expands to be larger than the diameter of the upper and lower rigid plates when it is compressed between the upper and lower rigid plates.
2. A seal for a tube having a projection coming out of the tube as recited in claim 1 , and further comprising compression means extending through said second openings for moving the upper and lower rigid plates toward each other to compress the flexible plate, said compression means including an injector tube extending through said second openings.
3. A seal for a tube having a projection coming out of the tube as recited in claim 2 , wherein there is a plurality of said flexible plates between said upper and lower rigid plates and wherein said compression means includes at least one nut threaded onto the injector tube.
4. A seal for a tube as recited in claim 2 , wherein said upper and lower rigid plates and said flexible plate are located inside a chemical reactor tube, with a projection from the tube extending through said first aligned openings and with said flexible plate sealing against the inner surface of said chemical reactor tube and sealing around the projection.
5. A seal for a tube as recited in claim 2 , wherein each of said upper and lower rigid plates and said flexible plate also defines a third opening, and said respective third openings are vertically aligned.
6. A seal for a tube as recited in claim 5 , and further comprising a tube received in said aligned third openings.
7. A seal for a tube having a projection coming out of the tube as recited in claim 2 , wherein said compression means further includes a compression sleeve surrounding said injector tube above said upper rigid plate.
8. A seal for a tube having a projection coming out of the tube as recited in claim 7 , wherein said compression means further includes at least one nut threaded onto the injector tube above said compression sleeve.