CA1306386C - Seal saver - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

This invention consists of a novel filter combination which is disposed and adapted to be placed within a centrifugal pump between the impeller and the mechanical seal or packing thereof, for the purpose of protecting the mechanical seal or packing therein from the contaminants in the liquid being pumped by the centrifugal pump, the device consists of a plurality of annular rings, joined by means, each having vents around the circumferences thereof. The rings are designed to utilize the angular motion of the fluid and the forces on the contaminants induced by the rotation of the impeller, shaft and seal of the centrifugal pump, to remove contaminants from the fluids entering the area of the mechanical seal and thus prolong the use-life of the seal, this invention may be used in any adaptable existing centrifugal or other pumps, as a retro-fit.

Description

8EAL 8AV~R 8P}:CIFICATIOM

This device is a filter which is installed within a centrifugal pump between the impeller and the mechanical seal or packing. Its purpose is to protect the mechanical seal or packing from contaminants in the liquid being pumped.
Generally speaking, the present invention provides a seal cavity protector for use with rotary fluid equipment a seal cavity of which is defined by a rotary shaft, a shaft housing and seal means engaging the shaft, the protector comprising: an annular generally cup-shaped element adapted to pass the shaft therethrough and to be secured to the housing at the entrance to the seal cavity, the element including a plurality of circumferentially spaced apart, first and second vent passages extending through the wall thereof; and an annular inwardly extending flange defining an opening through which the shaft can pass and including a plurality of circumferentially spaced apart third vent passages extending therethrough.
In the past, filtration, cooling systems, and flushing systems have utilized various forms of pumping devices which rotate within the pump housing, or a special housing, to direct the flow of the fluid around the seal.
Generally these systems do not remove contaminants, but only re-circulate fluids for cooling and lubrication.
The existing technology, utilizes either special pumping ring-seals or special housings, which cannot be easily retro-fitted into existing production pumps.
The invention described herein is designed for easy retro-fit into existing centrifugal pumps, turbines and other fluid-flow machines. The present invention occupies very little axial space and does not a~fect normal maintenance LCN ~

~L3~

procedures. The present invention can be used tc pro-tec-t any make of mechanical seal or pack~ng from contaminants in the fluid.
This invention further provides a re~circulating ~ilter in the housing of the pump, or other ~luid machine and provides clean, cooling, lubricating fluid to the mechanical seal or packing. The existing technology utilizes either special pumping ring seals or special housing, which cannot be retro-fitted into existing pumps.

The prior art does not solve the problem which the present Invention is devised to solve, ~or example, United States Patent No. 49128,362 would draw contaminants into the seal area and would require specially designed pump.

Uni~ed States Patent No. 3,999,882 does not filter contaminants from the liquid and utilizes specially designed mechanical seals to develop pumping action. United States Patent No.
4,386,780 describes a system ~or removing contaminants from the liquid in a centrifugal pump, but requires that the pump be designed to accomodate a special housing in which complicated mechanical dev1ces are housed and would make routine pump maintenance a difficult task. United States Patent 4,273,509 describes a cleaning unit which operates externally to the pump on the fluid pressure and ~low developed by the pump.

-- 2 ~

~3r,~

In the drawings which illustrate the embodiments of this invention and in which the same numbers are used to indicate the same parts:
FIGURE 1 illustrates a lateral cross-sectional view of the invention.
FIGURE 2 illustrates a horizontal cross-sectional view of the invention.
FIGURE 3 illustrates a horizontal cross-sectional view of the invention in operation within a pump having a mechanical seal.
FIGURE 4 illustrates the use of the invention in combination in a pump, using any standard form of packing.
This configuration requires the utilization of ring 1 only.

In the drawings, the number 1 indicates a circular cup-~haped hollow unit or element closed at the rear thereof, having vents 3 and 4 therein. This unit 1 is connected to an annular ring or flange 2, having a further series of vents 5 on the outside circumference of the ring 2. In ~igure 3, the number 6 indicates a pump housing; the number 7 indicates the impeller; the number 8 indicates the mechanical seal; the number 9 indicates the shaft; the number lo indicates contaminants inside the pump.
The mode of use and operation of this invention is as follows:
In Figure 3, a mechanical seal 8 is located into the pump housing 6 between the impeller 7 and shaft 9. The shaft 9, impeller 7 and the mechanical seal 8 being rotated by the 342-2/LCM:jj 3 ` ~ `

pump drive-motor, (not shown), impart a rotational motion to the fluid throughout this area. My Seal Saver encourages and utilizes this rotational or cyclonic motion, and further introduces controlled axial motion of the fluid.
The outside ring 1 incorpora~es two series of vehts, one series 3 on the inside circumference or radially extending portion thereof and one series 4 on the outside circumference or arcuate intermediate portion thereof. The vents 3, open inwardly and direct the rotating flow along the axis of the shaft 9 toward he mechanical seal 8. The vents 4 open outwardly and direct the rotating flow towards the impeller 7.
The inside ring or flange 2 has one or more sets of vents 5 on its outside circumference opening inwardly and directing the rotating flow toward the vents 4 in the outside circumference of the outside ring ~. A small gap is left between ring 2 and the shaft 9. The vents are so sized that vent series 4 is the largest, and vent series 3 is the smallest. This ensures velocity increase of fluid entering vents 3. Contaminants 10 thus accelerated in this rotational fluid, will contact ring 2 and be ejected through vent 4. The cleaner fluid will pass under ring 2 and enter the area of the mechanical seal 8, or the packing. Any contaminants entering under ring 2, will be centrifuged to the outside circumference of the seal cavity and will be ejected by the outflow through the vents 5.
The above specification and disclosure illustrates the details and embodiments of my discovery and invention.

342-2/LCM:jj 4 .,~``
.

~ ~3~63~
It wlll be understood that the foregoin~ specification and disclosure is an example o~ the preferred embodiment of my invention and as lt is obvious that my invention may be changed, adapted or applied in other forms or uses than are set out herein, I, therefore, claim as my invention and dlscovery~ all forms, changes and adaptions of my invention which may be fairly deemed to fall within the scope of my appended claims.

~3~:P63~

SUPPIEMENTa~XY DISCLOSURE

The foregoing has described bri~fly, but accurately, the concept of the present invention. Further research, ~owever, has led to a better understanding of the principles involved in the invention and to additional configurations and embodiments which utilize those principles. Those principles, as well as the additional configurations and embodiments will be described hereinafter with reference to the following figures wherein:
FIGURE 5 shows, in partial cross-section, an elevational view of typical fluid equipment utilizing the seal cavity protector of this invention.
FIGURE 6 is an enlarged cross-sectional view at the entrance to the seal cavity, showing the present invention schematically.
FIGURES 7, 8 and 9 are front, rear and side views respectively of the preferred form of the protector of this invention.
FIGURE 10 is a cross-section taken on the line 10-lo of FIGURE 7.
FIGURE 11 is a partial perspective view showing the fluid flows associated with the present invention.
FIGURE 12 is an enlarged cross-sectional view at the entrance to the seal cavity.
FIGURE 13 is a view similar to FIGURE 12 showing a multi-zone protector in accordance with the present invention.

342-2/LCM:jj 6 ~3~
. ~

~ IGURES 14 and 15 show ~ront an~ side ~iews respectively of a basic form of the present invention.
FIGURE 16 is a view similar to FIGURE 12 showing the embodiment of FIGURES 14 and 15 in place.

Figure 5 illustrates a typical snvironment for the device of the present invention. In this case the rotary fluid e~uipment comprises a centrifugal pump 11 which is operated by an alectric motor 12. The motor drives a rotary shaft 14 contained within a shaft housing 16 of the bearing housing 13.
The shaft is connected to a centrifugal impeller 18 which, as it rotates, draws fluid in through inlet 20 and pumps the fluid out through radial outlet 22. The shaft 14 is typically supported by bearings 24 and seals 26 are provided to protect the bearings from contaminants within the fluid which enter the seal cavity 2~. As seen in Figure 1 the seal cavity 28 is defined in general by the shaft 14, the shaft housing 16 and the seals 26.
Figure 6 illustrates a somewhat enlarged view of the area where the shaft 14 connects to the impeller 18. It is seen therein that the shaft 14 has a shoulder 30 with a smaller diameter portion 32 extending therefrom. A threaded portion 34 projects from the portion 32. The impeller 18, with vanes 36, fits over the portion 32 and abuts the shoulder 30. A
washer 38 and nut 40 are drawn tight against the impeller 18 to clamp it to the shaft 14 and a nose piece 42 fits over the nut, washer and exposed end of the threaded portion 34. With the impeller in place there is a thin gap G between the inner 342-2/LCM:jj 7 .
.

~3~

face 4~ o~ the impeller 18 and ~he outer face 46 of the shaft housing 16.
Seal members 26 are typically held in p~sition on the shaft by a gland or by set screws (not shown~.
The flow pattern of the fluid in a typical centrifugal pump sets up countercurrents which flow spirally inwardly within the gap G, as shown generally by the arrows ~- Such countercurrents create high pressure areas at the entrance to the seal cavity 28 and they also carry contaminant material which, if it enters the seal cavity, can damage the seals 26 and the rotary shaft 14.
It should perhaps be pointed out that the spirally inward counkercurrent flow (arrows X) will generally be adjacent the surface 46. Since there are dynamic forces at work there will, of course, be a spirally outward flow as well, such as along surface 44, taking fluid away from the shaft area. However, since the contaminant material carried by the fluid usually has a greater density than the fluid itself there can be an accumulation oE contaminant material in the area of the shaft within the gap G, and possibly within the seal cavity ~8.
The present invention is intended to overcome the problems indicated above, the present invention taking the form of a seal cavity protector as shown schematically by reference number 60 in Figure 6. As seen in Figure 6 the seal cavity protector is positioned at the entrance to the seal cavity 28.
It should be noted thak all features of the protector 60 are 342-2/LCM:jj 8 ".,~

. ' " "

~ ~3~`t;3~
not shown in Figure 6. Reference should be made to Figures 7 to 11 to be discussed hereinbelow.
The seal cavity protector can take one of several configurations depending on whether its prime function is to reduce the contaminant level in ~he seal cavity and surrounding areas or to reduce fluid pressures in the seal cavity. The preferred embodiment will perform both function~ and it is that embodiment which is shown in Figures 4 to 11. Other embodiments, both simpler and more sophisticated will be illustrated later.
Figures 7 to 9 show front, rear and side views of the seal cavity protector 60 from which it will be seen that it includes a first annular flange 62 extending outwardly from one end of a cylindrical axially extending sleeve member 64. A
second annular flange 66 extends inwardly from the other end of the sleeve member 62 and defines a circular opening 68 through which a shaft 14 can pass with a small clearance.
A cup-shaped annular element 70 has a first generally cylindrical, axially extending wall portion 70 which, as seen in Figure 10 fits within the sleeve member 64. The wall portion 72 should be secured to the sleeve member as ~y welding to achieve a leak-proof seal therebetween. The element 70 also includes an annular, generally radially extending, second wall portion 74 which defines a circular opening 76 of essentially the same diameter as opening 68 in flange 66 so that the shaft 16 can pass completely through the protector 60. An annular transition wall portion 78 connects the wall portions 72, 74 togsther and in the drawings the wall portion 78 is shown as 342-2/LCM-jj 9 `' ~
`

13~ 3~

being arcuate although it could just as easily be straight or have any other degree of curvature than what is shown.
The element 70 is provided with a plurality of first vent passages 80 circumferentially spaced apart around the element and positioned essentially in the transitibn wall portion 78. Each first vent passage is defined by a first slit 82 extending through the transition wall portion 78, the first slit being oriented generally radially, and by a second slit 84 which is oriented generally circumferentially adjacent the lo first wall portion 72. The slits together define a first ~lap section 86 which is bent oukwardly along a fold line 88 to provide a passage from the interior zone so~of the protector to the exterior. I~' The element 70 is also provided with a plurality of circumferentially spaced apart second vent passages 92 which are positioned in the second wall portion 74. Each vent passage 92 includes a third slit 94 extending radially outwardly from the opening 76 and a fourth slit 96 which extends circumferentially from the outer end of the third slit 94. These slits define a second flap section 98 which is bent inwardly along a fold line 100 to provide a passage from the exterior to the inner zone 90 within the gap G. The vent passages 92 are oriented along tangents to the circular opening 76.
The second flange 66 at the "rear" of the protector is provided with a plurality of circumferentially spaced apart third vent passages 102. Each vent passage 102 includes a fifth slit 104 extending generally radially from adjacent the 342-2/LCM:jj 10 ~3~
. ~,.

sleeve member 6~ and a sixth slit 106 extending generally circumferentially adjacent the sleeve member. These slits define a third flap section 108 which is bent inwardly along a fold line l1o to provide a passage from the seal cavity 28 to the interior zone 118 of the pxotector 60.
The first flange 62 is provided with means, such as circumferentially spaced apart apertures 112, for securing the protector 60 to the shaft housing 16. Machine screws 114 could pass through the apertures 112 for reception in threaded holes (not shown) in the housing. Preferahly, the housing will be recessed as shown in Figure 6 so that the front surface of flange 62 will be generally flush with the housing surface 46.
The first flange 62 is also provided with a plurality of generally triangular raised flow deflectors 140 which have angled, sloping walls 142, 144, which in turn are inclined downwardly and away from a radially outermost apex 146.
Depending on the rotation of the shaft 14 either the walls 142 or 144 will increase the circumferential flow component of the fluid spiralling inwardly adjacent the protector so as to improve the capture of such fluid by the vent passages 92 and to improve thè flow past the outlets of the vent passages 80.
Reference may now be made to Figures 11 and 12 for a more complete explanation of the operation of the seal cavity protector of this invention.
Figure 11 shows a seal cavity protector 60 mounted to a shaft housing 16, at the entrance to seal cavity 28, by way of machine screws 114. A cen~rifugal impeller 1~ is partially illustrated, attached in a conventional manner to the shaft 14, 342-2/LCM:jj 11 -- - .

~l3~r~3~

which shaft passes through the proteckor 60 from the seal cavity 28.
Figure 11 also illustrates particulate contaminant material 116 which moves spirally inwardly within the gap G to the vicinity of the shaft 16. Some of the particulate material will pass into the seal cavity by way of the clearance gap between the shaft 14 and the edge of the openings 68 and 76.
Additional particulate material will be forced to enter the annular zone 118 within the protector by way of the second vent passages 92. Such vent passages are oriented in the direction of shaft rotation such that fluid and contaminants rotating with the shaft 14 and impeller 18 will be forced to pass through the vent passagas 92. Furthermore, the vent passages 92 are oriented tangentially so as to direct fluids and contaminants passing therethrough towards the outer reaches of the zone 118 wherein reside the irst vent passages 80. Such flow, through the second vent passages 92, is shown by the arrows B in Figure 11. The rotating flow within the gap G, caused by the shaft 14, is shown by the arrows A.
As ~luid rotates within the protector's annular zone 118 a portion of the contaminant material contained therein will accumulate towards the circumferentially outer portion of the zone due`to centrifugal force, and another relatively clean portion of the contaminant flow will enter the seal cavity betwQen the shaft 14 and the edge of the second flange opening 68. As the shaft 14 rotates such material will flow within the cavity 28 along lines shown by the arrows C, D (Fig. 11) to exit the cavity via the third vent passages 102, re-entering 342-2/LCM:jj 12 ~3f~
.

the zone 118. Once a steady state has been r~ached, shortly after shaft start-up, there will be continuous flow along the shaft surface into the seal cavity, through the vent passages 92 into the zone 118, through the vent passages 102 into the zone 118, and through the vent passages 80 bask into the gap G. The more highly concentrated contaminant material flows radially outwardly through the gap G in a countercurrent to the contaminant material flowing spirally inwardly, and in~ardly flowing material being within a boundary layer close to the shaft housing surface 46.
Within the seal cavity 28 the path taXen by the contaminant material will depend on the specific gravity thereof. Tests have shown that heavier material will follow a short path (e.g., dotted lines F in Fig~ 12) while lighter material is more prone to follow a longer path (line K in Fig.
12). Tests have also shown that shortly after start-up the cavity 28 will be almost empty of contaminant material and that any material which does enter the cavity is almost immediately removed therefrom.
It would appear that since there is relative movement between the fluid in the gap G and the stationary protector 60 there will be a substantial pressure drop in the areas downstream of the first vent passages and this in turn promotes the flow of fluid through the second and third vent passages.
Also, the pressure within the zone 118 will be lower than the pressure within the seal cavity as the fluid i5 moving more rapidly within the zone 118. This in kurn enhances the fluid flows within the seal cavity and the flow of fluid, containing 342-2/LCM:jj 13 . ..~

~3~P~;3~

contaminants, back through the third vent passages 102 into the zone 118 for ejection through the first vent passages 80.
In view of the fact that there are pressure reductions axially across the protector 60 it becomes clear that the protector 60 serves to reduce the pressure within the seal cavity 28 below the pressure that it would experience ahsent the protector. Thus given a situation wherein there are virtually no contaminants to worry about, the present invention could be used to reduce pressures within the seal cavity 28.
Of course, any protectors installed for the primary purpose of pressure reduction would still operate to reduce the level of whatever contaminants might be present in the operating fluid.
Figures 13 to 16 illustrate two directions in which the design of a pressure reducing seal cavity protector might take.
Figure 13 for example shows a view, similar to Figure 12, in which there is a plurality of axially adjacent annular zones 118, 118a, 118b..., each additional zone being defined by an annular flange 66a, 66b... with each flange 66a, 66b... having a set of fourth vent passages 102a, 102b... defined in the same manner as passages 102. Each zone will be at a lower pressure than the axially adjacent zone as one enters the seal cavity with the cavity being at a pressure lower than what it would be with but a one-zone protector 60 in place at the entrance thereto. If, in any particular instance, the pressure in cavity 28 could be reduced sufficiently by using a multi-zone protector it might then be possible to replace high-pressure " seals in the cavity with low-pressure seals with a consiequent saving in seal purchase and installation costs.

j 342-2/LCM:jj 14 .
'; ~`

~ 3.3~a~

Figures 1~ to 16 on the other hand illustrate a simpler, more basic, version of the invention which miyht be used primarily for pressure reduction. The protector 120 of this e~oodiment utilizes a cup-shaped element 122 which has an axially extending first annular wall portion 124, a second annular wall portion 126 and a transition wall portion 128 which may be arcuate, as shown, straight or of any other suitable configuration. The front or second wall portion 126 defines a circular opening 130 through which the rotary shaft 0 i5 adapted to pass.
A plurality of circumferentially spaced apart yenerally tangentially directed vent passages 132 is provided in the transition wall portion 128, which passages serve to permit fluid to pass from the seal cavity 28 through the protector to the gap & between the housing 16 and the impeller. Each vent passage is defined by a slit 134 which passes through the transition wall portion 128. On one side of the slit a portion of the transition wall portion is depressed as at 135 to provide a larger opening through the wall portion 128.
Optionally, a portion of the transition wall on the other side of the slit is raised relative, as at 138, to the surrounding wall material to further increase the opening at the slit. As seen i~ Figure ~ the depressed portions 132 are all on the . .
` ~ ~ same side of the slits and the passage openings are oriented r~j~y so as to face in the direction of fluid rotation.
As the shaft 14 rotates, fluid within the gap G will `` ~ pass by the vent passages 132 and will cause a low pressure area to be created adjacent the element 122 outside the seal 342-2/LCM:jj 15 ~3~3B~
cavity 28 which will in turn cause fluid to be drawn from the seal cavity 28 through the vent passages 132. Fluid within the cavity is replenished through the space between the shaft and the edge of the opening 130 but the resulting steady-state operating pressure within the seal cavity 28 will be less than the normal operating pressure absent the protector 120.
Furthermore any contaminants carried into the cavity 28 will be quickly removed therefrom due to the outward fluid flow through the vent passages, as descxibed for the first embodiment.
If improved performance is required, a set of vent passages similar to passages 92 could be provided in front wall portion 126 so as to increase the flow into and then out of the cavity.
Clearly, the present invention provides a seal cavity protector which is capable of reducing operating pressures within the cavity and which also services to scavenye particulate contaminant material from the seal cavity, thereby reducing the possibility of damage to the shaft and/or the seals within the cavity. Specific embodiments of the invention have been described, which embodiment~ illustrate the principles associated with the invention.

342-2jLCM:jj 16 .

Claims (24)

1. A seal cavity protector for use with rotary fluid equipment a seal cavity of which is defined by a rotary shaft, a shaft housing and seal means engaging the shaft, said protector comprising: an annular generally cup-shaped element adapted to pass the shaft therethrough and to be secured to the housing at the entrance to the seal cavity, said element including a plurality of circumferentially spaced apart, first and second vent passages extending through the wall thereof; and an annular inwardly extending flange defining an opening through which the shaft can pass and including a plurality of circumferentially spaced apart third vent passages extending therethrough.

2. The protector of Claim 1 wherein said element includes an axially extending portion, a radially extending portion and an arcuate intermediate portion, said first vent passages being in said intermediate wall portion and opening outwardly thereof, said second vent passages being in said radially extending portion and opening inwardly thereof, and said third vent passages opening inwardly of said flange.

3. The protector of Claim 2 wherein each of said vent passages is oriented for fluid flow therethrough in the direction of shaft rotation.

342-2/LCM:jj 17 CLAIMS SUPPORTED BY THE SUPPLEMENTARY DISCLOSURE

4. A seal cavity protector for use with rotary fluid equipment a seal cavity of which is defined by a rotary shaft, a shaft housing and seal means engaging the shaft, said protector comprising an annular generally cup-shaped element adapted to pass the shaft therethrough and to be secured to the housing at the entrance to the seal cavity, said element including a plurality of circumferentially spaced apart, generally tangentially directed, first vent passages extending through the wall thereof whereby, with the protector in place and as the equipment rotates, a low pressure area is created adjacent said element outside the seal cavity and fluid within the seal cavity is drawn therefrom through the vent passages.

5. The protector of Claim 4 wherein said element includes an axially extending first wall portion, a radially extending second wall portion defining a first opening through which the shaft can pass, and a transition wall portion connecting said first and second wall portions together, said first vent passages being located within said transition wall portion.

342-2/LCM:jj

6. The protector of Claim 5 wherein each of said first vent passages includes a generally radially extending slit through the transition wall portion with transition wall material at one side of the slit being depressed relative to surrounding transition wall material.

7. The protector of Claim 6 wherein transition wall material at the other side of the slit is raised relative to surrounding transition wall material.

8. The protector of Claim 5 wherein each of said first vent passages is defined by an L-shaped slit extending through the transition wall portion with one leg of the slit being oriented generally radially and the other leg being oriented generally circumferentially adjacent the first wall portion, the legs of the slit defining a first flap section which is bent outwardly relative to the surrounding transition wall portion.

9. The protector of Claim 6 including a plurality of second vent passages extending through said second wall portion, each of said second vent passages including a third radial slit extending through said second wall portion from said opening and a fourth circumferential slit extending from said third slit, said third and fourth slits defining with the edge of said opening a second flap section which is bent inwardly relative to surrounding wall material.

342-2/LCM:jj

10. The protector of Claim 8 including a plurality of second vent passages extending through said second wall portion, each of said second vent passages including a third radial slit extending through said second wall portion from said opening and a fourth circumferential slit extending from said third slit, said third and fourth slits defining with the edge of said opening a second flap section which is bent inwardly relative to surrounding wall material.

11. The protector of Claim 9 including an annular axially extending sleeve member within and to which said first wall portion of said element is secured, said sleeve member including an annular outwardly extending first flange at one end, adjacent said second wall portion, and an annular inwardly extending second flange at the other end thereof, said second flange defining a second opening through which the shaft can pass, said second flange also including a plurality of circumferentially spaced apart third vent passages extending therethrough.

12. The protector of Claim 10 including an annular axially extending sleeve member within and to which said first wall portion of said element is secured, said sleeve member including an annular outwardly extending first flange at one end, adjacent said second wall portion, and an annular inwardly extending second flange at the other end thereof, said second flange defining a second opening through which the shaft can 342-2/LCM:jj pass, said second flange also including a plurality of circumferentially spaced apart third vent passages extending therethrough.

13. The protector of Claim 11 wherein each third vent passage includes a fifth slit extending through the second flange radially inwardly from adjacent said sleeve and a sixth slit extending through the second flange, circumferentially adjacent said sleeve from said fifth slit, said fifth and sixth slits defining a third flap section which is bent inwardly.

14. The protector of Claim 13 wherein each of said first, second and third vent passages is oriented for fluid flow therethrough in the direction of rotation of the shaft passing through said first and second openings.

15. The protector of Claim 14 wherein said first flange includes a plurality of circumferentially spaced apart apertures therethrough each adapted to receive a fastener suitable for securing said first flange to a face of the equipment shaft housing at the entrance to the seal cavity.

16. The protector of Claim 15 wherein said first flange includes a plurality of circumferentially spaced apart generally triangular raised flow deflectors on the outer surface thereof, said deflectors serving to increase the circumferential flow component of fluid moving radially 342-2/LCM:jj inwardly adjacent said protector during operation of the rotary fluid equipment.

17- The protector of Claim 12 wherein each third vent passage includes a fifth slit extending through the second flange radially inwardly from adjacent said sleeve and a sixth slit extending through the second flange, circumferentially adjacent said sleeve from said fifth slit, said fifth and sixth slits defining a third flap section which is bent inwardly.

18. The protector of Claim 17 wherein each of said first, second and third vent passages is oriented for fluid flow therethrough in the direction of rotation of the shaft passing through said first and second openings.

19. The protector of Claim 18 wherein said first flange includes a plurality of circumferentially spaced apart apertures therethrough each adapted to receive a fastener suitable for securing said first flange to a face of the equipment shaft housing at the entrance to the seal cavity.

20. The protector of Claim 19 wherein said first flange includes a plurality of circumferentially spaced apart generally triangular raised flow deflectors on the outer surface thereof, said deflectors serving to increase the circumferential flow component of fluid moving radially inwardly adjacent said protector during operation of the rotary fluid equipment.

342-2/LCM:jj

21. A seal cavity protector for use with rotary fluid equipment a seal cavity of which is defined by a rotary shaft, a shaft housing and seal means engaging the shaft, said protector comprising: a first annular flange adapted to be secured to the shaft housing at the entrance to the seal cavity; sleeve means extending axially from an inner annular edge of the first flange; a second annular flange extending radially inwardly from said sleeve means; and an annular cup-shaped element having a first wall portion within and secured to said sleeve means, a second radially extending wall portion and a transition wall portion between said first and second wall portions; said second wall portion and said second flange defining respective circular openings through which the shaft can pass; a plurality of circumferentially spaced apart first vent passages extending through said transition wall portion;
a plurality of circumferentially spaced apart second vent passages extending through said second wall portion; and a plurality of circumferentially spaced apart third vent passages extending through said second flange; said second and third vent passages opening into an annular zone bounded by said element and said second flange and said first vent passages opening out of said zone; whereby with said protector in place and as the equipment rotates a low pressure area is created adjacent said element outside the seal cavity, fluid carrying contaminant material is drawn into said annular zone through said second and third vent passages from adjacent said element and from within the seal cavity respectively and contaminant 342-2/LCM:jj 23 .

carrying fluid is drawn from said zone through said first vent passages for removal from the operating equipment.

22. The protector of Claim 21 wherein said second vent passages are oriented to direct fluid in a tangential direction relative to said element into said zone.

23. The protector of Claim 22 wherein: (a) each of said first vent passages is defined by an L-shaped slit extending through the transition wall portion with one leg of the slit being oriented generally radially and the other leg being oriented generally circumferentially adjacent the first wall portion, the legs of the slit defining a first flap section which is bent outwardly away from said zone; (b) each of said second vent passages is defined by a third radial slit extending through the second wall portion from the opening defined thereby and a fourth circumferential slit extending from said third slit, said third and fourth slits defining a second flap section which is bent inwardly into said zone; and (c) each of said third vent passages is defined by a fifth slit extending through the second flange, radially inwardly from adjacent said sleeve means, and a sixth slit extending through the second flange circumferentially adjacent said sleeve means from said fifth slit, said fifth and sixth slits defining a third flap section which is bent inwardly into said zone.

342-2/LCM-jj

24 24. The protector of Claim 23 including an axially extending sleeve extension and a radially inwardly extending annular third flange, said third flange, sleeve extension and second flange defining another annular zone, said third flange including circumferentially spaced apart fourth vent passages passing therethrough into said another zone, each of said fourth vent passages being defined by a seventh slit extending through the third flange, radially inwardly from adjacent said sleeve extension, and an eighth slit extending through the third flange circumferentially adjacent said sleeve extension from the seventh slit, said seventh and eighth slits defining a fourth flap section which is bent inwardly into said another zone.