US 3318251 A
Description (OCR text may contain errors)
F. H. SMITH 3,318,251
METHOD AND APPARATUS FOR PUMPING FLUID BODIES May 9, 1967 5 Sheets-Sheet 1 Filed June 21, 1965 May 9, 1967 3,318,251
METHOD AND APPARATUS FOR PUMPING FLUID BODIES Filed June 21, 1965 F. H. SMITH 5 Sheets-Sheet 2 fi'wezzfoat- Mal i/wwlw May 9, 1967 F. H. SMITH 3,318,251
METHOD AND APPARATUS FOR PUMPING FLUID BODIES Filed June 21, 1965 5 Sheets$heet 3 w 7? .92 a? O 82 I 2" \y T r y 9, 1967 F. H. SMITH 3,318,251
METHOD AND APPARATUS FOR PUMPING FLUID BODIES Filed June 21, 1965 5 Sheets-Sheet 4 Izweeziuz WWO May 9, 1967 F. H. SMITH 3,318,251
METHOD AND APPARATUS FOR PUMPING FLUID BODIES Filed June 21, 1965 5 Sheets-Sheet 5 Ill IIIIE aqMJx/JW z; m my.
'9 flibifowngy United States Patent G 3,318,251 METHOD AND APPARATUS FOR PUMPING FLUID BODES Frederick H. Smith, Lynnfield, Mass, assignor to Manton Gaulin Manufacturing Company, Inc., Everett, Mass.,
a corporation of Massachusetts Filed June 21, 1965, Ser. No. 465,409 8 Claims. (Cl. 103-42) This invention relates to a method and apparatus for pumping fluid bodies and, more particularly, the invention is concerned with an improved pump construction of the diaphragm pump class wherein tubular diaphragm members are subjected to pressure exertd through reciprocating plunger mechanism.
In operating a pump of the tubular diaphragm class, it is customary to exert pressure on the diaphragm members by means of a confined volume or volumes of a hy-' draulic fluid. Pumping performance may be materially affected if there occurs any appreciable change in volume of the hydraulic fluid which is being used to compress the diaphragm means and changes in volume tend to take place when a diaphragm pump is run continuously over extended periods at relatively high pressures.
For example, when a diaphragm pump is run at relatively high pressures, inefficiency or wear of sealing means utilized in the pressurizing apparatus may result in leakage of small amounts of the hydraulic fluid. Over a period of time such leakage may develop into a substantial loss and the operating life of the diaphragm may 'be undesirably affected. If hydraulic fluid is added to the system it must be done in a carefully controlled manner to avoid excessive stress in the diaphragm means.
The present invention is, in general concerned with an improved method and apparatus for diaphragm pumping which is designed to provide increased pumping efficiency at relatively high pressures, and it is -a chief object of the invention to devise a novel arrangement of parts which are so organized as to control and reduce wear while maintaining pumping performance at a high level.
It is another object of the invention to devise a combination of pumping components which are so arranged as to provide for rapid and simplified servicing of pressurizing and sealing components when necessary.
Still another specific object of the invention is to provide means for trapping small amounts of hydraulic fluid which escapes from the high pressure side of reciprocating plungers of the invention and to further provide for returning the trapped amounts of hydraulic fluid into the system so that a change in volume can be substantially avoided.
It is a further specific object of the invention to combine in a diaphragm type of pumping apparatus a novel arrangement of sealing box means for containing reciprocating plunger mechanism and high pressure sealing means in a conveniently accessible position for replacement and maintenance without requiring that the input and output conduits of the pumping apparatus be disconnected.
Another specific object of the invention is to provide in a diaphragm type of pumping apparatus novel means for adding to or replacing hydraulic fluid in a pumping system of the class noted; and still another object of the invention is to provide means for guarding the diaphragm and high pressure seal components as well as other working parts of a diaphragm type pump from excessive overload by the hydraulic fluid to thus imp-art a desirable pressure regulating safety factor which can 'be varied in accordance with any desired range of pressures to be exerted.
The nature of the invention and its other objects and novel features will be more fully understood and appreciated from the following description of a preferred embodiment of the invention selected for purposes of illustration and shown in the accompanying drawings, in which:
FIGURE 1 is a side elevational view of the pumping apparatus of the invention;
FIGURE 2 is a plan view of the pumping apparatus showing power driving means fragmentarily at one side thereof;
FIGURE 3 is a cross section taken on the line 33 of FIGURE 2;
FIGURE 4 is a detail cross sectional view on a somewhat larger scale similar to FIGURE 3 and illustrates a fluid circulatory valving arrangement for replacing fluid escaping past a sealing means in the system;
FIGURE 5 is another cross sectional view corresponding to FIGURE 4 but showing one of the sealing boxes partly disengaged from the cylinder block of the pump to provide access to the sealing devices contained in the sealing box; and
FIGURE 6 is a plan view of the cylinder block portion of the pumping apparatus in which a plurality of diaphragm elements are contained in separated relationship to one another.
The pumping apparatus of the invention includes, as principal parts thereof, an enclosure body for housing a plurality of diaphragm pumping members; a hydraulic fluid system for pressurizing the diaphragm pumping members including volumes of fluid contained in chambers in the enclosure body; and reciprocating plunger apparatus supported externally of the enclosure body for hydraulically actuating the hydraulic fluid system.
The apparatus is characterized by a novel arrangement of the parts noted to not only control wear and maintain maximum efliciency, but in addition to provide for greatly simplified servicing and replacement of parts in the plunger apparatus without having to disconnect the pump from the flow line which is to 'be operated.
In this novel arrangement of parts referred to, I provide a supporting base which is formed at its upper side with an elongated casing structure. The casing structure is designed with a housing section at one end for supporting a.
power driven crank shaft mechanism. A restricted intermediate section of the casing structure houses a reciprocating drive mechanism and the opposite end of the base receives and solidly supports the pump enclosure body in a preferably raised position. The advantages of this assembly are most fully disclosed below in connection with the further detailed description of the parts noted.
Referring more in detail to the structure shown in the drawings, numeral 2 denotes the supporting base which is formed at its upper side with an elongated casing structure 3 as is more clearly shown in FIGURES 1 and 2. The casing structure has mounted at one end a pump enclosure body 4 secured by fastenings as 4a and 4b which extend into the casing structure as suggested in dotted lines in FIGURES 1 and 2.
At its opposite end the casing structure is closed at its upper side by a cover part 7 and supported in the casing structure below the cover part 7 is power driving means consisting of a crank shaft 8 which is mounted for rotation in bearings 10 and 12. A motor M is disposed at some convenient point adjacent the base :as shown in FIGURE 2. The motor driving shaft 14 extends through the casing structure as noted in FIGURE 2 and has its inner extremity received in bearing means 16.
Fixed to the shaft 14 is a gear 18 which is adapted to mesh with and drive a gear 20 on crank shaft 8. Connecting rods 22, 24 and 26 are attached to the crank shaft and at their outer ends the connecting rods are pivotally attached to cross-head members 28, 30 and 32. Also attached to the cross-heads 28, 30 and 32 are adaptor rods 34, 36 and 38 which are slidably received through an intermediate bearing section B of the casing structure in bearing portions 40, 42 and 44.
URES 3 and 4.
3 As will be noted in FIGURES 1 and 2, the three con- 'necting rods 22, '24 and 26 are positioned around the crank shaft 8 at substantially uniformly spaced intervals to provide for the plungers 46, 48 and 50 periodically advancing and exerting pressure pulsations at successive intervals as particularly indicated by the three positions of travel assumed by plungers 46,48 and 50 in FIGURE '2. There is thus accomplished'relatively high pumping portion of restricted width and at its upper side this intermediate body portion '5 is provided with a large opening 9 which is designed to expose the connected ends of the adaptors 34, 36 and 38, as well as the plungers 46, 48 and 50, and to furnish an access and work opening to facilitate the maintenance and replacement of pumping components without interference with the flow line generally. comprised by the product inlet I and the product outlet 0.
i In combination with the plungersnoted and the access opening 9, I further provide in the enclosure body 4 a plurality of plunger seal boxes denoted by the numerals 60, 62 and 64 which are best shown in FIGURE 2.
These seal boxes in one preferred form comprise cylindrical sleeve portions having tapered ends as 60a as rep resented by the seal box 62 in FIGURES 3 and 4. The tapered ends 60a are threaded and engaged in correspondingly threaded openings as'66, 66a and 66b in the enclosure body as shown in FIGURES 3, 4 and 5. It will be apparent, therefore, that the seal boxes, as well as the plungers may, by reason of the access opening 9, be installed and removed at any time. This is further illustrated in FIGURE 5 in which a seal box 62 and disconnected plunger unit 48 is shown partly removed through the access opening 9.
The threaded openings 66 in the enclosure body 4 are more clearly shown in FIGURE 6 and as indicated therein communicate with a plurality of vertically disposed fluid retaining chambers as 65, 65a and 65b formed in an intermediate portion of the enclosure body to contain separated volumes of hydraulic fluid, one of which volumes is generally indicated by the letter H in FIG- Itwill also be observed from an inspection of FIGURE 6 that the chambers 65, 65a and 65b connect with the threaded openings 66, 66a and 66b and also oppositely located pressure relieving passageways 67, 67a and 67b. As is further shown in FIGURES 3, 4 and 5, each of thechambers 65, 65a and 65bis closedat support as 82. Similarly, each of the chambers is closed at its lower end by a check valve member as 84 in a valve support 86. Sealably connected betweenthe valves 80 and :84 in the chambers 65, 65a and 65b are tubular diaphragm members :as 88.
It is againpointed out that by means of the arrangement of-parts-described, and particularly the location of the tubular diaphragms in a vertically disposed position occurring substantially at right angles to the 'path of travel of the three reciprocating plungers, it
becomes possible to arrange the sealing boxes so that they can be removed without disconnecting or otherwise changing the diaphragm pumping structure. Even more important is the fact that the axes of the f pumping-strokes are very compactly arranged while the size of the diaphragms may be made relatively large or small. This is a distinct advantage for dealing with varying pumping requirements. Moreover, the vertically dis posed arrangement of the diaphragms makes possible .its upper end by a check ,valve as 80 mounted in a valve location of an accumulator for each plunger so that selective release of pressure may be accomplished as each diaphragm is pressurized at any given point.
An important feature of the removable seal boxes described is the provision of fluid trapping spaces in each of the seal boxes. These fluid trapping spaces form a part of novel fluid recovery means operable in response to reciprocating movement of the plungers above-noted to collect small amounts of fluid escaping past the high pressure seals, and to return the collected fluid back into the high pressure side of the system.
The fluid recovery means includes fluid passageways formed through the enclosure body and communicating with the high pressure side of the. plungers, conduits extending between the fluid trapping spaces and the said enclosure body passageways, and check valve means located in the conduits.
Considering the fluid recovery means in greater detail, attention is directed to FIGURES 3, 4 and 5. As shown therein each of the seal boxes has an inner peripheral surface which is formed with a shouldered part as 59, against which is tightly fitted packing or seal members as 68 which are designed to withstand high pressure and which are held in place by means of split rings as 68a and retaining rings 68b. Also located at the opposite sideof the shouldered part 59 are low pressure sealing members as 70 held by split rings 70a and retaining rings 70b.
In accordance with the invention the shouldered part 59 in each of the seal boxes is also made of a diameter slightly larger than the diameter of plunger means received therethrough to thereby define fluid trapping spaces S. Connected through each of the seal boxes to communicate with the trapping spaces S are fluid conduits 90, 92 and 94 as shown in FIGURE 2.
One of these conduits 92 is more clearly shown in FIG- URES 3 and 4 and as will "be observed therein the conduit extends vertically upwardly for a short distance and then is shaped in a right angularly disposed manner to connect with a check valve unit 93, in turn connected to a fitting 95.
The fitting 95 has secured thereto a conduit portion 97 which extends through a fluid return passageway 98 terminating at a point immediately ahead of the path of travel of the plunger 48. By means of this arrangement small quantities of oil which escape by the high pressure packing member 68 and collect in the oil trapping space S, can be transferred back into the system. The valve 93, 'as is more clearly shown in FIGURE 4, includes a spring-loaded ball check 93a which normally closes the conduit 92 on the pressure stroke of the plunger 48. When the plunger is retracted suction opens the ball check against the action of a spring 93b and pumps fluid from the trapping space through the valve and downwardlythrough the conduit 97 into the body of fluid H occurring in front of the plunger 48. It will be apparent therefore that the operation of this fluid recovery means operates to prevent the loss of hydraulic fluid from the system and thus a substantially constant volume can be maintained in operation over long periods of time and as a consequence the pressurizing eflect of the plunger 48, acting through the hydraulic fluid of constant volume, tends to produce a substantially uniform contraction or compression of the diaphragm member 88. I
In the preferred form of the invention shown in the drawings, I may as earlier noted, also desire to include pressure relieving accumulator means for preventing overloading and damage to the'pumping components. in the event a sudden increase in pressure occurs. Such an increase may take place, for example, when the flow line is closed or blocked at the outlet side.
The accumulator means of the invention may, for example, consist of three accumulator units such as those shown in the drawings in FIGURE 2 and denoted by numerals 76, 77 and 78. Each of the accumulator units is fitted with threaded conduits as 76h, 77a and 78a engaged in the threaded openings 67, 67a and 67b in the outer side of the enclosure body 4.
As shown in FIGURE 3 the accumulator 77 comprises an outer casing and an inner compressible diaphragm 77' which is normally maintained at a desired pressure by means of gas such as nitrogen delivered through a conduit V3 from a supply source N. Hydraulic fluid normally surrounds the diaphragm 77 inside the casing 77. In the event the pressure in the flow line exceeds the pressure in the diaphragm, the latter member becomes compressed and relieves pressure to prevent damage to the pumping components.
Another desirable feature of the accumulator apparatus comprises valve means for automatically regulating pressure especially under conditions where a sudden rise in pressure in the product flow line may take place. The
valve means'includes a regulating valve V1 which controls the pressure of gas delivered from the supply member N and a bleeder valve V2 located between the regulating valve V1 and the diaphragm 77'. The bleeder valve is of a type such that it may be set to allow flow of gas at any desired pressure from member N to the diaphragm. In the event however pressure in the diaphragm as delivered by the regulating valve is suddenly exceeded for example by interference in the output side of the product flow line then the valve V2 will release pressure.
In a typical operation for instance assume the pump is delivering a fluid material through the product flow line at 1,000 p.s.i. and the accumulator diaphragm pressure is set by the regulating valve V1 at 1,100 p.s.i. while the bleeder valve is set at 1,200 p.s.i. As long as pumping pressure remains at or below 1,000 p.s.i. no change occurs. If, however, the pumping pressure rises through a range of 1,000 p.s.i. to 1,100 p.s.i., the accumulator diaphragm 77 will be compressed as a safety factor and the pumping apparatus is protected from overload in this range. The bleeder valve remains closed in this interval. Assume further that the pumping pressure rises above the range of 1,100 p.s.i. to pressures above 1,200 p.s.i. then the gas in the diaphragm Will have a corresponding rise in pressure and at values above 1,200 p.s.i. will be relieved through the valve V2 to prevent excessive overload of the pumping components. With a drop in pressure in the product flow line taking place thereafter, the gas discharged or released through valve V2 will then automatically be replaced from member N and the system is again set for the normal operating pressure of 1,000 p.s.i. in the flow line. The regulating valve also serves as a convenient and safe means of maintaining the accumulators in operation when increased pumping pressures are desired to be used.
The conduits 76a, 77a and 78a may also be employed to carry out another function, namely, the step of adding fluid to the system whenever this may be desired to be done. As shown in FIGURE 3, for example, the conduit 77a has provided therein a T into which is connected a pipe Y having a fluid receptacle R. The valve V3 may, when desired, be opened to permit fluid to flow by gravity into the conduit 70a and to become added to the system.
While I have shown and described preferred embodiments of the invention it is intended that changes and modifications may be practiced Within the scope of the appended claims.
1. In a diaphragm pump of the class described a base, power driving means in the base, a pump enclosure body mounted at one end of the base and having inlet and outlet ports for receiving and discharging a product fluid, said enclosure body being further recessed to form a plurality of chambers for receiving separated volumes of hydraulic fluid therein, tubular diaphragm members located in the chambers, valve means in said inlet and outlet ports and connected to the diaphragm members for controlling flow of product fluid therethrough, reciprocating plunger members supported in the frame and connected to the power driving means, cylindrical seal boxes for receiving said plungers, said cylindrical seal boxes being detachably connected to one side of the pump enclosure body and communicating With respective hydraulic fluid chambers, pressure relieving accumulator members connected to an opposite side of the enclosure body for mounting pressures exerted by the plunger at a predetermined value and a fluid filling receptacle and control valve connected between the pressure relieving accumulator members and the enclosure body.
2. A structure according to claim 1 in Which a conduit means extends between each of the cylindrical seal boxes and the separated volumes of hydraulic fluid on two sides of the plunger member to provide for returning small amounts of fluid escaping past the plunger in the cylindrical seal boxes.
3. A diaphragm pump including a supporting base formed at its upper side With an elongated casing structure, a power driven crank shaft mounted for rotation in one end of the casing structure, a pump enclosure body secured to the casing structure at an opposite end thereof, said enclosure body having inlet and outlet ports for receiving and discharging a product fluid and being further recessed to form a plurality of chambers for containing separated volumes of hydraulic fluid therein, tubular diaphragm members located in the chambers, valve means in said inlet and outlet ports and connected to the diaphragm members for controlling flow of product fluid through the the diaphragm members, reciprocating plunger members supported for sliding movement in the elongated casing and connected to the said crank shaft, cylindrical seal boxes for sealably receiving and guiding said plungers, said cylindrical seal box-es being detachably connected to one side of the pump enclosure body and communicating with respective hydraulic fluid chambers, and said elongated casing structure being formed with an access opening for exposing portions of the reciprocating plunger mechanism and the seal boxes whereby the seal boxes may be removed from the pump enclosure body.
4. A diaphragm pumpof the class described comprising a casing having a power driven crank shaft mounted therein, an intermediate plunger housing section extending from one side of the casing and having slidably re- "ceived therein a plurality of separated reciprocating plungers in connected relationship with the crank shaft, a fluid conducting enclosure .body detachably secured to the said plunger housing section and having inlet and outlet ports at opposite sides thereof, multiple diaphragm pump means mounted in the fluid conducting enclosure body and responsive to movement of the said plurality of plungers, said fluid conducting enclosure body being formed with a plurality of separated hydraulic fluid chambers in which separated volumes of hydraulic fluids are pressurized by the said plungers, said multiple diaphragm pump means including a plurality of tubular diaphragm members located in respective hydraulic fluid chambers in spaced relation to the chamber Walls, each of said tubular diaphragm members being sealably connected to respective inlet and outlet ports in the enclosure body, valve means in the said inlet and outlet ports for controlling periodic flows of product fluid through each of the diaphragm members when successive pressure pulsations are exerted by the reciprocating plungers and sealing means in the enclosure "body for maintaining the plungers in sealing relationship with respective hydraulic fluid chambers.
5. A structure according to claim 4 in Which the multiple diaphragm pump means further includes a plurality of pressure relieving members detachably mounted at one side of the fluid conducting enclosure body in communication with respective hydraulic fluid chambers to provide means for selectively relieving pumping pressure exerted by any one of the said diaphragm members.
6, A structure according to claim 5 in which the sealing means in the enclosure body consists of a plurality of sealing boxes detachably secured therein and including sealing means for sealably retaining respective plunger members, and said plunger housing section at the upper side thereof being recessed to provide an access opening for detaching and removing the said plungers and sealing boxes.
7. A structure according to claim 6 in which the sealing boxes are formed with oil trapping spaces and have connecting with the oil trapping'spaces conduit means for conducting trapped hydraulic fluid into respective hydraulic fluid chambers.
8. A structure according to claim 4 in which the multiple diaphragm pump means further includes a plurality of pressure relieving members detachably mounted at one sideof the fluid conducting enclosure body in communication with respective hydraulic fluid chambers to provide means for selectively relieving pumping pressure exerted by any one of the said diaphragm members, and the said pressure relieving members include means for introducing hydraulic fluid into any one of the hydraulic fluid chambers.
References Cited by the Examiner UNITED STATESPATENTS 1,627,257 5/1927 Stevens 103-44 1,950,107 3/1934 Guinn et a1. 138-30 2,395,330 2/1946 Houser 103-44 2,839,002 6/1958 Williams 103-44 X 2,971,465 4/1961 Caillaud 103-44 3,151,562 10/1964 Swartz 103-44 3,168,045 2/1965 Sebastiana 103-44 ROBERT M. WALKER, Primary Examiner.