Pneumatic Pump

Abstract

There is provided a pneumatic pump (10) comprising a tubular steel frame (11) and a disc-shaped pressure vessel (12) including a lower, tangential transfer port (14) and an upper, radial ventilation port (15). A transfer assembly (16) on the port (14) includes an inlet assembly (17) having a positive-close non-return valve (21) and a delivery outlet assembly (20). A venturi assembly (22) applies suction to the ventilation port (15) and has an exhaust vent (24) including a closure assembly (25) selectively operable to cycle between a suction phase and a pressurized phase. A two way T-valve (40) selectively allows venturi exhaust air to pass selectively into either a diffuser/muffler (35) or a delivery line (42) downstream of an outlet non-return valve.

Claims

1-29. (canceled)

30. A pneumatic pump including: a supporting frame; a pressure vessel in the form of a spherically-derived shape flattened in the vertical plane and supported by said frame, and having a lower transfer port and an upper ventilation port; a transfer assembly communicating with said transfer port and including an inlet for pumpable material, and a delivery outlet, one or both of said inlet and said outlet having a non-return valve; a constant-flow, compressed air-operated venturi assembly having a suction side communicating with said ventilation port and an exhaust vent including closure means selectively operable to cycle said ventilation port between a suction phase and a pressurized phase, venturi exhaust air during said suction phase being selectively vented to atmosphere or injected into a delivery line portion downstream of said outlet; and control means being adapted to selectively operate said closure means.

31. The pneumatic pump according to claim 30, wherein the spherically-derived shape is in the form of a disc flattened in the vertical plane to be taller and longer in the supporting frame than it is wide, the penetration of the transfer port being substantially tangential to the lowest point on the pressure vessel.

32. The pneumatic pump according to claim 30, wherein the transfer assembly comprises a conduit extending from the transfer port and having a T-connection with side branch connection substantially adjacent the transfer port and an axial connection adjacent the side branch connection.

33. The pneumatic pump according to claim 30, wherein at least the inlet valve is fitted with a non-return valve.

34. The pneumatic pump according to claim 33, wherein non-return valve or valves each comprises a swing valve.

35. The pneumatic pump according to claim 34, wherein at least the inlet swing valve is positively assisted and maintained in a closed position by an actuator controlled in concert with the closure means.

36. The pneumatic pump according to claim 30, wherein the constant flow, compressed air-operated venturi assembly comprises an elongate venturi body comprising a venturi orifice interposed between the suction side communicating with said ventilation port and the exhaust vent, the orifice cooperating with an air jet supplied by an external compressed air source to induce depression in the suction side of the body upstream of the jet while the closure means is open.

37. The pneumatic pump according to claim 30, wherein the closure means is selected from low inertia and/or balanced valves operated by a pneumatic actuator.

38. The pneumatic pump according to claim 30, wherein the control means is an air control over air delivery system.

39. The pneumatic pump according to claim 38, wherein an air-analogue programmable logic controller is used.

40. The pneumatic pump according to claim 30, wherein said venturi exhaust air during said suction phase is selectively vented to atmosphere or injected into the delivery line portion downstream of said outlet by a manual two-way valve.

41. The pneumatic pump according to claim 35, where the swing valve includes: a valve body having a swing chamber interposed between an inlet and an outlet and defining a flow axis therethrough and a chamber extension extending away from the flow axis; an annular valve seat located in said swing chamber about an opening into said inlet; a valve gate assembly mounted in said chamber and comprising a supporting body pivoted to walls of the chamber extension and having a front surface that mounts a resilient valve closure disc, and adapted to move between a closed position with said resilient valve closure disc substantially occluding said opening and an open position whereby fluid may pass from said inlet to said outlet; and valve closer means comprising a linear actuator mounted on the chamber extension and presenting a push rod operable to selectively urge and maintain said valve gate assembly in said closed position, the supporting body having a back surface adapted to cooperate with the push rod.

42. The pneumatic pump according to claim 41, wherein the back or body portion surface includes a camming surface portion that the pushrod will first contact if the valve is not fully closed.

43. The pneumatic pump according to claim 41, wherein said resilient valve closure disc is formed of polyurethane.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The invention will be described with reference to the following non-limiting embodiment of the invention as illustrated in the drawings and wherein:

[0037] FIG. 1 is a front view of pneumatic pump apparatus in accordance with the present invention;

[0038] FIG. 2 is a sectional side view of the apparatus of FIG. 1;

[0039] FIG. 3 is a diagram of air, fluid and control flows of the apparatus of FIG. 1;

[0040] FIG. 4 is a detail sectional view of a swing valve suitable for use in the embodiment of FIG. 1;

[0041] FIG. 5 is a perspective view of the apparatus of FIG. 1; and

[0042] FIG. 6 is a cover for the apparatus of FIG. 1.

[0043] In the figures there is illustrated a pneumatic pump 10 comprising a supporting tubular steel frame 11 and a steel, disc-shaped pressure vessel 12 supported on the frame at anchor points 13. The steel pressure vessel 12 includes a lower, tangential transfer port 14 and an upper, radial ventilation port 15.

[0044] A transfer assembly 16 communicates with the transfer port 14 and includes an inlet assembly 17 for pumpable material, and a delivery outlet assembly 20. The inlet assembly 17 includes a positive-close non-return valve 21, described in more detail hereinafter.

[0045] The ventilation port 15 mounts a compressed air-operated venturi assembly 22 having a suction side 23 communicating with the ventilation port 15 and an exhaust vent 24 including a closure assembly 25 selectively operable to cycle the ventilation port 15 between a suction phase and a pressurized phase.

[0046] The inlet assembly 17 and delivery outlet assembly 20 in this embodiment essentially comprise respective swing valve assemblies mounted on adjacent branches of a T-connector 26 connected to the transfer port 14. Each of the swing valve assemblies 17, 20 is provided with terminal camlock connectors 27. The inlet swing valve assembly 17 includes a positive-close actuator 30, described in more detail hereinafter.

[0047] The venturi assembly 22 comprises an elongate venturi body 31 including a venturi orifice 32 interposed between the suction side 23 communicating with the ventilation port 15 and the exhaust vent 24. The orifice 32 cooperates with a constant-flow air jet 33 supplied by an external compressed air source 34 to induce depression in the suction side 23 of the body 31 upstream of the jet 33. During the suction phase the open closure assembly 25 allows the venturi exhaust to vent through a diffuser/muffler 35 to reduce high-dB air screech.

[0048] The closure assembly 25 comprises a low-inertia ball valve, lubricationless ball valve 36 operated by a single action, spring return pneumatic actuator 37. The air source 34 may be shut off by a stop cock 38, providing a master on-off switch for the apparatus.

[0049] The diffuser/muffler 35 is mounted on a side branch of a manual two way T-valve 40, the straight-through path of the T-valve 40 being in fluid communication with a modified top cap 41 on the outlet swing valve assembly 20, thereby allowing venturi exhaust air to pass selectively into either the diffuser/muffler 35 or the delivery line 42 downstream of the outlet non-return valve. In order to maintain a straight venturi exhaust flow path, the venturi body 31 upstream of the jet 33 and orifice 32 may be a curved conduit 43 connected to the ventilation port 15.

[0050] In FIG. 3 is illustrates an embodiment of a control arrangement of the apparatus of FIGS. 1 and 2 wherein the compressed air source 34 supplies (at supply pressure) both the venturi assembly 22 and a double switching (push-pull) primary air solenoid 44. The air distributed by two outlets 45 of the solenoid 44 pass to respective ends of a double acting pneumatic dashpot 46 which acts as a timer element. The piston 47 of the dashpot 46 mounts a double ended rod 50 which, at the respective ends of travel triggers a respective air switch 48 providing feedback control to the solenoid 44.

[0051] The venturi assembly 22 depresses the pressure vessel 12 when the closure assembly 25 is open, whereupon exhaust air may pass, depending on the setting of the manual T-valve 40 to the diffuser/muffler 35 or into the delivery line downstream of the swing non-return valve 20.

[0052] The timer element push-pulls the closure assembly 25 to timer-operate the cycling of the venturi assembly 22 between the suction and pressurization phases. Simultaneously with the pressurisation phase commencing, the slow-acting (dashpot), push-pull, positive-close actuator 30 positively closes the swing valve gate 17. On transition to the suction phase, positive-close actuator 30 slightly delays opening of the swing valve gate 17, allowing vacuum accumulation in the pressure vessel 12.

[0053] As best illustrated in FIG. 4 the inlet assembly 17 includes a cast stainless steel valve body 51 having a swing chamber 52 interposed between an inlet end 53 and an outlet end 54. An annular, integral valve seat 55 is formed in the swing chamber about an opening into the inlet end 53. The inlet end 53 mounts a threaded collar 56 supporting a cam-lock male spigot 57. The outlet end 54 mounts a threaded collar 58 supporting a threaded side branch of the T-connector 26.

[0054] A chamber extension 60 includes a bore 61 that is substantially perpendicular to the flow path through the valve.

[0055] A valve gate assembly comprises a stainless steel supporting body 62 pivoted at 63 to the walls of the chamber extension 60 and has a front surface 64 that mounts a resilient polyurethane valve closure disc 65 with a bolt 66 and spreader washer 67. The front surface 64 lies in a plane that includes the pivotal axis of the valve gate. The supporting body 62 has a back surface 70 adapted to cooperate with valve closer means 71 comprising a double acting, linear actuator dashpot actuator 30 screw-mounted to the chamber extension 60 to present a push rod 72 adapted to pass closely adjacent the back surface 70. The back surface 70 includes a camming surface portion 73 that the pushrod 72 will first contact if the valve is not fully closed.

[0056] In use, the apparatus may be housed in a removable housing 74 having an air supply cut-out 75, an inlet cut-out and an outlet cut-out (not shown). The cover includes bolt holes 77 adapted to secure the cover 74 to the frame 11 at mount tags 80.

[0057] It will of course be realised that while the above has been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as is set forth in the claims appended hereto.