Mechanical leak-proof coupling

Details Mechanical leak-proof coupling Mechanical leak-proof coupling

1997-11-03

2001-09-11

Walton, George L. (Department: 3753)

Fluid handling

With leakage or drip collecting

C073S046000, C285S010000, C285S011000

Reexamination Certificate

active

06286541

ABSTRACT:

FIELD OF THE INVENTION
The present invention is generally directed to leak-proof couplings for conduits, pipes and the like and, more particularly, a mechanical leak-proof coupling for a gas-carrying pipe connected to a vibrating chamber.
BACKGROUND OF THE INVENTION
Over the years, a wide variety of different couplings have been developed for conduits, pipes and the like. These couplings have typically taken the form of mechanical couplings that are either rigid or semi-rigid in form, especially where there is a requirement that the coupling be leak-proof in applications where the conduit or pipe carries a liquid or gas therethrough. With such mechanical couplings, it has been commonplace to utilize a seal that is in contact with each of the adjoining ends of the conduit or pipe.
While the design of such couplings and seals has evolved to a significant extent, there exists certain applications where conventional rigid or semi-rigid mechanical couplings are not suitable. This is the case, for instance, whenever two conduit or pipe sections must be joined in a leak-proof manner while at the same time permitting some degree of relative movement therebetween. For this purpose, conventional mechanical couplings have not proven to be useful since they cannot accommodate the relative movement between the two conduit or pipe sections.
Unfortunately, conventional flexible couplings also may not be suitable for every application where a leak-proof connection is necessary between two relatively movable conduit or pipe sections. Most typical flexible couplings have taken the form of a sleeve of a flexible material such as rubber or the like, and there are many applications in which the conduit or pipe sections must carry a high temperature fluid or a fluid having corrosive or other deleterious characteristics. In these cases, it is difficult, if not impossible, to select a material for the conventional flexible coupling that is capable of withstanding the extreme environmental characteristics of the fluid.
Since the fluid would normally be in contact with the conventional flexible coupling through a gap between the ends of the two conduit or pipe sections, this problem is known to be especially critical for those applications in which the ends of the conduit or pipe sections must accommodate some degree of relative movement therebetween.
In one particular application, a pressurized gas is transferred from a stationary source to a vibrating chamber through a gas-carrying conduit or pipe. This application is one in which the vibrating chamber may comprise an integral portion of a vibratory fluidized bed that is utilized to reclaim foundry sand by burning off the binder. The gas-carrying conduit or pipe typically will include a first conduit or pipe section having both an upstream end connected to the stationary source for the pressurized gas and a spaced coupling end. The gas-carrying conduit or pipe will also include a second conduit or pipe section having both a second coupling end near the first coupling end of the first conduit or pipe section and a spaced downstream end connected to the vibrating chamber. This application typically utilizes pressurized air that is heated to a temperature of at least 600° F. and is delivered to the vibrating chamber for fluidizing sand in the vibratory fluidized bed. Due to the relative movement of the conduit or pipe sections caused by the vibrating motion, there must exist a gap between the first and second coupling ends thereof.
For this application, a conventional flexible mechanical coupling will be understood to present a problem in view of the high temperature of the pressurized air. There must necessarily be a way to accommodate the relative movement between the first and second coupling ends of the conduit or pipe sections, thereby requiring the gap therebetween, but this means that either the material of the flexible mechanical coupling must be such as to withstand the high temperature of the pressurized air, or the flexible mechanical coupling must be isolated from exposure to the hot pressurized air. In either case, any solution in the form of a conventional flexible mechanical coupling has quite necessarily been understood to be complex and expensive.
The present invention is directed to overcoming one or more of the foregoing problems while achieving one or more of the resulting objects by providing a unique mechanical leak-proof coupling.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a mechanical leak-proof coupling for a gas-carrying pipe. It is a further object of the invention to provide a leak-proof coupling for a gas-carrying pipe having a pair of communicating pipe sections in an apparatus suitable for transferring a pressurized gas from a stationary source to a vibrating chamber through the gas-carrying pipe sections. It is a further object of the present invention to provide such a mechanical leak-proof coupling for transferring hot pressurized air.
Accordingly, the present invention is directed to a leak-proof coupling for a gas-carrying pipe which includes a first pipe section having an upstream end which receives a pressurized gas from a source and which also includes a second pipe section having a downstream end for discharge of the pressurized gas therefrom. The pressurized gas is received through the upstream end of the first pipe section from a source and flows through the first pipe section from the upstream end to a first coupling end for discharge therefrom. The pressurized gas is then received by a second coupling end of the second pipe section and flows through the second pipe section from the second coupling end to the downstream end for discharge therefrom. Still additionally, the first and second coupling ends of the first and second pipe sections are disposed in closely spaced adjacent relation to define a gap therebetween through which at least some of the pressurized gas could escape in the event of a negative pressure differential in the region of the first and second coupling ends externally of the first and second pipe sections.
In the context of this invention, it will be understood that the term “leak-proof” has reference to an arrangement in which the vast majority of gas is confined to flow through the gas-carrying pipe but does not exclude the possibility that relatively small amounts of gas may escape to atmosphere through the coupling. Also, in the context of this invention, it will be understood that the term “negative pressure differential” has reference to a condition in which the static pressure as measured externally of the first and second coupling ends would be lower than the static pressure as measured internally of the first and second coupling ends.
With this arrangement, the present invention achieves the mechanical leak-proof coupling by utilizing means for providing a positive pressure differential in the region of the first and second coupling ends externally of the first and second pipe sections to thereby prevent the pressurized gas flowing through the first and second pipe sections from being able to escape through the gap defined by the first and second coupling ends of the first and second pipe sections.
As will be appreciated, and again in the context of the present invention, the term “positive pressure differential” has reference to a condition in which the static pressure as measured externally of the first and second coupling ends is higher than the static pressure as measured internally of the first and second coupling ends.
In one form of the invention, the positive pressure differential means includes enclosure means located externally of the first and second pipe sections and in communication with a second source of pressurized gas. In another form of the invention, the positive pressure differential means includes groove means externally of the first and second pipe sections in communication with a second source of pressurized gas. In yet another form of the invention, the positive pressure differential means comprises an annular pressurized r

Affiliated with

Also associated with

Rating

Mechanical leak-proof coupling does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Mechanical leak-proof coupling, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mechanical leak-proof coupling will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2438460