High pressure gas silencer

A silencer reduces the noise from a venting high or low pressure gas outlet port. The exhaust holes are on the side of the cylindrical body. A lower nut is loosened to point the exhaust holes downwind for safety concerns. A disposable soft module embodiment and an all metal non-disposable embodiment is disclosed.

FIELD OF INVENTION

The present invention relates to reducing the noise from vented high pressure gas releases.

BACKGROUND OF THE INVENTION

Venting high pressure gas or steam to atmosphere during a plant or Gas Facility startup or shutdown is a common practice. These controlled releases cause dangerous noise and severe pressure drops on the vent valves. Additionally “Pigging” is a common maintenance function used in high pressure gas lines. Pigging in the context of pipelines refers to the practice of using devices known as “pigs” to perform various maintenance operations. This is done usually without stopping the flow of the product in the pipeline. These operations include but are not limited to cleaning and inspecting the pipeline. This is accomplished by inserting the pig into a “pig launcher” (or “launching station”)—an oversized section in the pipeline, reducing to the normal diameter. The launching station is then closed and the pressure-driven flow of the product in the pipeline is used to push the pig along down the pipe until it reaches the receiving trap—the “pig catcher” (or “receiving station”). Each time a “pig” is launched or retrieved, the high or low pressure gas line trap must be vented to atmosphere. Again this causes dangerous noise and stress on the release valve.

CU Services LLC, Elk Grove, Ill. makes a silencer labeled a D800. It has a flange attachment to a release pipe as shown inFIG. 1, labeled as CU 1. Release holes H vent the gas up as shown by arrow CU out. Inside the body of the CU 1 silencer are one or more circular plugs with a plurality of small vent holes. The CU 1 silencer does reduce the noise and stress on the release valve V shown inFIG. 1.

What is needed in the art is a silencer that can direct the vented gas downwind in any direction. What is also needed is a silencer that has improved noise suppression using a replenishable soft barrier wall. The new silencer also offers more portability due to its threaded connection vs. a flanged connection. The present invention meets these needs.

SUMMARY OF THE INVENTION

The main aspect of the present invention is to provide a silencer (also called a noise suppressor) for high and low pressure gas releases that uses a replenishable soft barrier to suppress noise and allows for a replacement barrier when chemicals or erosional velocity destroy the soft barrier.

Another aspect of the present invention is to provide an adjustable gas outlet port to allow the operator to vent the gas downwind.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring first toFIG. 1a “pig” launcher/receiver3has a main pipe4that needs de-pressurizing. Arrows IN and OUT show gas flow. A prior art silencer CU 1 fits onto a four inch vent valve V via a flange5. High pressure (400 psi plus or minus) and gaseous exhaust is vented straight up as shown by arrow CU OUT.

The present invention silencer10has a narrowed connector end11that could be sized for any one of several pipe diameters such as ½, ¾, 1 or 2 inch. Alternately a single one inch nut14could connect to a swage piece12to connect the silencer10to a valve13of any diameter. Height d4can vary from about 6 inches to about 18 inches. Design choice to raise above a worker's head could lengthen the height d4to over 18 inches.

The operator loosens nut14and determines the downwind direction. Then he twists the silencer10so the vent holes15face downwind. Then he tightens the nut14. Then he opens the valve13and discharges the gaseous exhaust downwind. This is safer for the operator than the prior art CU 1 silencer, because the CU 1 exhaust could blow volatile gas or liquid into the operator's face by the ambient wind.

A tap valve17allows an exit pressure to be measured by gauge18. The cap16is removable. Arrows IN and OUT show the gas flow.

Referring next toFIG. 2the silencer10may have an inside diameter d1=1.90″. The disposable soft module21has an outside diameter d2slightly larger than 2.00″. A central rod22is held in place up against cap16. The disposable soft module21consists of a top flange23T and a bottom flange23B. These are preferably stainless steel discs welded to rod22. A soft sound barrier25can be “8800” polyethylene foam (or in the range of 8200-9000) or an equivalent such as steel wool. The harder upper barrier24(reticulated particle foam or mesh disc or both) resists chafing. It can be made of a reticulated particle foam. Both soft barriers have holes as shown. Each flange23T,23B may have four to eight holes29at a diameter of about ⅛ to about ½ inch. Each soft barrier24,25can also be welded to rod22. Each soft and hard barrier has vent holes11as shown.

To replace a soft module21, the gas pressure is shut off. The cap16is removed. The old soft module21is replaced with a new soft module21consisting of items22,23T,24,25, and23B. The cap16is replaced. The gas pressure is turned on.

Referring next toFIG. 3Athe bottom connector assembly30has the nut14free spinning on lower shaft31. It is tightened or loosened on threads32to either allow the silencer to turn or to lock it in place. The threads33of collar34are permanently tightened onto the gas line swage piece or pipe nipple12. A ridge (not shown) at the base of the silencer holds the nut14in a spinable fashion. Thus, tightening the nut14on threads32draws the ridge tight against the nut14, locking the silencer at a chosen angle.

Referring next toFIG. 3Ban alternative union40adds three bosses41to the outside of nut14to allow hammer strikes.

Referring next toFIG. 4the handle10H can be used to turn (arrows T) the silencer10to a desired angle so that the holes15face downwind DW. Nominal dimensions of the fourteen holes shown in holes15are center to center spacing of about ⅜ inch and hole diameter of about 3/16 inch.

Referring next toFIG. 5the silencer100has a two inch connector base50. Otherwise it is identical to silencer10. Nominal dimensions are d4=13 to 18 inches, d3=2 inches, d5=3 inches.

Referring next toFIG. 6the soft module21is shown in detail. The top flange23T must locate under the holes15at point23TT as shown inFIG. 5.

Referring next toFIG. 7the silencer101functions the same as silencers10,100. The nut14tightens onto a connector509that has a flange connection510to the gas piping.

Referring next toFIG. 8a non-disposable model of a silencer800is shown. The cap16may have threads as shown, but it could be permanently attached. An all metal sound module801has a plurality of (stainless steel) flanges23T,23M,23B. This unit is not as quiet as the soft module embodiments, but it could be used in extremely caustic gas systems, or it could be chosen as a lower maintenance choice.