GB2168437A

GB2168437A - A positive pump, in particular, for fluid foodstuffs containing solid matter

Info

Publication number: GB2168437A
Application number: GB08530297A
Authority: GB
Inventors: Vittorio Bertoli
Original assignee: Rossi and Catelli SpA
Current assignee: Rossi and Catelli SpA
Priority date: 1984-12-14
Filing date: 1985-12-09
Publication date: 1986-06-18
Also published as: IT8440115A0; IT1180935B; FR2574865A1; BE903831A; GR852974B; FR2574865B1; GB8530297D0; ES549936A0; IT8440115A1; ES8701911A1; DE3543559A1; GB2168437B; PT81675A; NL8503420A; PT81675B; JPS61145376A

Abstract

A positive pump is disclosed which is designed for fluid foodstuffs containing solid matter, and has an inlet valve (2) and an outlet valve (5) provided with a respective first and second poppet (3, 6) reciprocated to open and close by way of a pulsed pressure supply that operates relative double acting pistons (8, 9) integral with the rear of the poppet stems; each poppet is provided with a cutting edge (11, 13) which registers exactly in the relative valve seat. <IMAGE>

Description

SPECIFICATION A positive pump, in particular, for fluid foodstuffs containing solid matter The invention disclosed relates to a positive pump, in particular, for fluid foodstuffs which contain solid matter.

Not infrequently, there is a requirement in the food processing industry for pumping fluid foodstuffs that contain solid matter e.g. jams, marmalade, pickle, tomato juice containing pulp, fruits and vegetables generally, fruit salad, chopped meats, mussels, mushrooms, pastes, rice, etc...

The utilization of positive pumps in displacing such foodstuffs is generally accompanied by the drawback that solid matter entrained in the foodstuff can produce an adverse affect on seating of the inlet or outlet valves of such pumps when closing, thereby occasioning poor operation of the pump as a whole. The object of the invention described herein is that of overcoming the aforementioned drawback, providing a positive pump that will displace fluid foodstuffs in which solid matter is entrained, and ensure faultless operation of the valves of the pump itself.

The object stated above, and other objects besides, are realized by a pump according to the invention; such a pump is of a type comprising a sliding plunger reciprocated by drive means, which takes in foodstuff through an inlet provided with a first poppet valve and displaces it through an outlet provided with a second poppet valve, and is characterized in that the poppet of each such valve is provided with a cutting edge, projecting frontally from its working face in such a way that solid matter lodged between the working face of the poppet and the valve seat is sliced through as a result of the poppet registering in the seat.

A preferred embodiment of the positive pump disclosed will now be described in detail, by way of example, with the aid of the accompanying drawing, which is a section through the pump.

The pump comprises a sliding plunger 1 reciprocated by drive means consisting of a crankshaft 16 and a connecting rod 17; with the crankshaft 16 rotating, the plunger 1 strokes back and forth in alternation within a cylinder 18.

4 denotes an inlet through which foodstuff to be displaced is taken into the pump, and which communicates with the cylinder 18 by way of a first cylindrical hole 14 constituting the seat of an inlet valve 2 incorporating a first poppet 3.

7 denotes an outlet communicating likewise with the cylinder 18 by way of a second cylindrical hole 15 that constitutes the seat of an outlet valve 5, this in its turn provided with a second poppet 6. The stem of the first poppet 3 connects at rear with a first double acting piston 8 which is reciprocated, in axial alignment with the first poppet 3, by pulsed pressure supplied via respective ports 1 9a and 19b. The stem of the second poppet 6 connects similarly at rear with a second double acting piston 9, reciprocated likewise in axial alignment with the poppet 6; pulsed pressure is supplied thereto via respective ports 20a and 20b.

Pulsed pressure causes the inlet and outlet poppets to open and close forcibly such that the opening and closing movement of the valves, caused by alternating pressure-vacuum conditions produced during operation of the plunger 1, is supplemented by the force of the pressure pulses impinging on the pistons 8 and 9. An advantageous effect is thus obtained, namely, more decisive operation of the poppets when registering with and distanced from their seats.

In order to ensure that both valves 2 and 5 open and close at the prescribed moment, the pulsed pressure source is controlled by the drive means which operate the plunger 1; a preferred embodiment would incorporate an encoder (not illustrated) relaying electrical signals, according to the angular position of the crankshaft 16, for operation of solenoid valves (not illustrated) following a preset sequence such as will produce the pulsed pressure required for opening or closing movement of the poppets. Needless to say, the train of pressure pulses will be such as to open the inlet and close the outlet during the intake stroke, and to open the outlet and close the inlet during the displacement stroke.

The first poppet 3 is provided with a cutting edge 11 projecting frontally from its working face 10, which has a circular perimeter; the cutting edge itself exhibits an acute angle in profile, and is concentric with the face of the poppet. The outermost perimeter of the cutting edge 11 matches the perimeter of the first hole 14, and is positioned so as to register exactly therein when the valve 2 is closed.

The second poppet 6 is provided similarly with a cutting edge 13 projecting frontally from its working face 12, the circular perimeter of which exhibits an acute angle profile and is concentric with the poppet face; the outer perimeter of this cutting edge 13 is matched to the perimeter of the relative cylindrical hole 15, and positioned such as to register exactly therein when the valve 5 is closed.

The cutting edge may be embodied in any given shape other than that described as long as it possesses the capability of slicing through solid matter that becomes lodged between the working face of the poppet and the valve seat, each time that the valve closes.

The cutting edge might be embodied integral with the seat, and the working face of the poppet embodied plain; such an arrangement would clearly be equivalent, in terms of the art, to the one illustrated. The drawing shows the configuration of the pump when at standstill, with both poppets distanced from their respective valve seats, drawn downward by their own weight, in order to illustrate component parts of the poppets.

During operation of the pump, the inlet and outlet valves will open and close alternately according to whether the pump is on the intake or the displacement stroke. To re-iterate, the opening and closing movement of both valves is brought about, not only by the intake and displacement strokes of the plunger, but also by the pulsed pressure supply impinging on the two valve pistons 8 and 9, as a result of which it becomes possible to enlarge the valve passages. Whenever either valve closes, its cutting edge registers in the respective cylindrical hole and slices through any solid matter that may be lodged between the poppet and the seat, aided in so doing by virtue of the force applied to the piston, clearly enough. Thus, one prevents the possibility of solid matter sticking fast under the working face of the poppet in such a way as to obstruct the closing movement of the valve, and occasion poor operation of the pump.

Claims

1. A positive pump, in particular for fluid foodstuffs containing solid matter, of the type comprising a sliding plunger (1) reciprocated by drive means, that takes in foodstuff through an inlet (4) provided with a first poppet valve (2) and displaces it through an outlet (7) provided with a second poppet valve (5), characterized in that the poppet (3, 6) of each such valve is provided with a cutting edge (11, 13) projecting frontally from its working face (10, 12) in such a way that solid matter lodged between the working face of the poppet and the valve seat is sliced through as a result of the poppet registering in the seat.

2. Positive pump as in claim 1 wherein the stem of the first and of the second poppet connects at rear with a first and a second double acting piston (8, 9) respectively, each reciprocated by a pulsed pressure supply the train of which is controlled by the drive means which operate the plunger.

3. Positive pump as in claim 1 wherein the outer perimeter of each cutting edge matches the perimeter of the hole that constitutes the respective valve seat, and is positioned so as to register exactly in the seat when the valve is closed.

4. Positive pump as in claim 2 wherein an encoder relays electrical signals, according to the angular position of the crankshaft of the plunger drive means, for operation of solenoid valves which follows a preset sequence such as will produce the pulsed pressure supplied to the respective chambers of the first and second double acting pistons.

5. Positive pump as in claim 3 wherein the cutting edge has a circular perimeter, exhibits an acute angle in profile, and is concentric with the working face of the poppet.