Nippon Pillar Packing Co., Ltd.

Hitachi, Ltd.

Nippon Plant Packing Co. Ltd.

Eiji Okumachi

Toshihiko Fuse

Taiji Hashimoto

Masanobu Ninomiya

Satoshi Fujiwara

Tao Hu

Tadayuki Shimizu

Sadamitsu Yamauchi

A shaft-seal device for high-temperature fluid including a seal case () formed as a metallic cylindrical structure of a single unit and comprised of a main body portion (), first and second holding portions (), first and second partition portions (), a channel formation portion () forming a minute annular channel () with the outer circumference surface of a rotary shaft (), and an o-ring holding portion (). The seal case is installed in an apparatus housing () with first and second o-rings () in between. The intra-seal case region (A), in which sealing rings () of mechanical seals () are provided, and the high-temperature fluid region, which is an intra-apparatus housing region (A), are partitioned by a cooling chamber () into and from which coolant () is supplied and discharged via feed/discharge coolant paths ().

Shaft-seal device for high-temperature fluid

A non-contact-type mechanical seal that keeps a rotary seal ring from vibrating in what is called a pneumatic hammer fashion. For this purpose, an annular space is formed between an outer circumferential surface of the rotary seal ring and an inner circumferential surface of a holder portion of a spring retainer . The annular space is sealed by a pair of O rings . In addition, seal gas leading passages are provided in the rotary seal ring through which spaces between seal end faces communicate with the annular space . Seal gas is supplied to static pressure generating grooves , and led into the annular space through seal gas leading passages . The seal gas presses O rings against the outer circumferential surfaces of the rotary seal ring and the inner circumferential surface of the holder portion of the spring retainer , thereby firmly holding the rotary seal ring

Non-contact type mechanical seal

A shaft sealing apparatus,comprising a seal case,mounted on a tank shell,of rotary equipment, a rotary seal ring,fixed to the rotary shaft,of the rotary equipment, a stationary seal ring,held in the seal case,opposite to the rotary seal ring,and movable in the axial direction, a coil spring,to thrust the stationary seal ring,against the rotary seal ring,, a gas feeding channel,formed out of a series of gas passages running through the seal case,and the stationary seal ring 4 and opening between the two seal end faces,of the two seal rings,, and a gas jetting mechanism to jet, selectively, a seal gas,such as nitrogen and a sterilization gas,such as steam through the gas feeding channel,into between the seal end faces,. In normal operation, the shaft seal apparatus,functions to seal at the relatively rotating portions of the end faces,of the seal rings,, while holding the seal ends,in a non-contact state, by jetting a seal gas,such as nitrogen into between the two seal end faces,. In sterilization mode, a sterilization gas,such as steam is jetted into between the two seal end faces,instead of the seal gas,, sterilizing at least the gas feeding channel,and the seal end faces

Shaft seal apparatus

A non-contacting shaft sealing device comprises an even number of dynamic pressure generating grooves arranged in the peripheral direction on a sealing end face of either the seal case side or the rotary shaft side. Each dynamic pressure generating groove comprises a shallow L-shaped groove of a specific groove width and depth and includes a fluid lead in part extending in the radial direction from a peripheral edge of the high pressure side of the sealing end face and a dynamic pressure generating part extending in the peripheral direction from the end portion thereof. Each groove is symmetrical with respect to one adjacent groove on one side thereof around a first sealing end face diametral line passing between adjacent fluid lead-in parts or symmetrical with respect to a second groove on the other side around a second sealing end face diametral line passing between the dynamic pressure generating grooves. The groove land ratio .theta..sub.1 /.theta..sub.2 in the peripheral direction is 0.5 to 0.9 wherein the angle of intersection .theta..sub.1 is the angle between a third sealing end face diametral line running along the fluid lead-in part of the dynamic pressure generating groove and a fourth sealing end face diametral line on which the end portion of the dynamic pressure generating part is positioned, while the angle .theta..sub.2 is the angle between the fourth sealing end face diametral line and the third sealing end face diametral line.

Non-contacting shaft sealing device

A non-contacting shaft sealing device in which an even-number of dynamic pressure generating groove groups are arranged in the peripheral direction thereof on a sealing end face of the seal case side or a sealing end face of the rotary shaft side. Each dynamic pressure generating groove group is composed of one or plural shallow L-shaped grooves of a specific groove width comprising a fluid lead-in part extending in the radial direction from a peripheral edge of high pressure side of said sealing end face and a dynamic pressure generating part extending in the peripheral direction from the end portion thereof. When the dynamic pressure generating groove group is composed of plural L-shaped grooves, those L-shaped grooves are arranged close to each other at an equal pitch without crossing each other such that the end portion of each dynamic pressure generating part is positioned on a fourth sealing end face diametral line. Each dynamic pressure generating groove group is symmetrical with respect to each of the adjacent dynamic pressure generating groove groups on both sides thereof around a first sealing end face diametral line passing between those fluid lead-in parts (between the fluid lead-in parts of the outermost side when the dynamic pressure generating groove group is composed of a plurality of the L-shaped grooves) or a second sealing end face diametral line passing between those dynamic pressure generating groove groups.

In a non-contacting shaft sealing device of the type wherein a sealing end face of a case seal and a sealing end face of a rotary shaft seal rotate relative to each other in a non-contacting state while being separated by a film of fluid derived from the high pressure region being sealed, one sealing end face is provided with an even number of dynamic pressure generating groove groups arranged in the peripheral direction on the sealing end face. Each dynamic pressure generating groove group has plural approximately L-shaped linear dynamic pressure generating grooves each composed of a fluid lead-in part extending in the radial direction from the peripheral edge of the sealing end face so as to communicate with the high pressure region, and a dynamic pressure generating part extending in the peripheral direction from the end portion of the fluid lead-in part with the dynamic pressure generating grooves not crossing each other and being arranged in the radial direction. Two adjacent dynamic pressure generating groove groups are symmetrical around the diametral line of the sealing end face.

Non-contacting shaft sealing device with grooved face pattern

A seal device of the non-contact type having seal faces formed by those end faces of a rotating seal ring and a stationary ring which are perpendicular to axes of the two rings, and also having dynamic pressure generating grooves formed in one of the seal faces at a certain interval in the circumferential direction of the seal face each groove having a first spiral groove portion and a second terminal portion being formed continuous from the front end of each of the first spiral groove portions, extending along the circumferential direction of the seal face but across its corresponding first spiral groove portion, and provided with a closed front end. The seal device can be used at high speed and under high pressure and it can correct the tilting of its seal faces, which is caused by pressure and heat added, to prevent them from being contacted with each other. Even when the difference of pressures added to them changes, the seal device can keep them parallel to each other to reduce the amount of liquid leaked to a greater extent.

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Sanda, Japan

Eiji Okumachi