WO1985005703A1

WO1985005703A1 - Level regulator

Info

Publication number: WO1985005703A1
Application number: PCT/FR1985/000140
Authority: WO
Inventors: René Mariotti
Original assignee: Mariotti Rene
Priority date: 1984-06-05
Filing date: 1985-06-04
Publication date: 1985-12-19
Also published as: EP0182840A1; FR2565373A1

Abstract

The regulator is adapted to maintain constant the level of a fluid in a tank which periodically feeds a vat provided on top of the tank and which is emptied after each fed cycle. It comprises a closed chamber (8) which is also provided on top of the tank and communicating with the latter by means, on one hand, of an air intake pipe (10) which plunges into the tank (5) up to the h level which is to be kept constant and, on the other hand, of an inverted U pipe (11) with equal legs and of which the shorter leg opens freely into the chamber (8), and of which the longest leg opens into the tank (5) and of which the curved portion is at a level lower than the periodical filling level of the vat (1'), said chamber (8) being topped by an inverted bottle-like fluid reserve (9) of which the neck (12) plunges into the chamber (8). The regulator is, amongst other applications, applicable to the hot constant keeping of a fluid level without being influenced by the cold fluid level.

Description

Level regulator.

The present invention relates to a level regulator adapted to maintain constant the level of a fluid in a reservoir periodically supplying a tank which overcomes it and which is emptied after each supply. Such a regulator can be applied, for example, to keep constant the level of hot oil contained in a

I buffer tank periodically supplying the frying tank of an industrial fryer in accordance with that which is described in French patent application No. 2,501,491 to the Applicant.

For understanding the invention, reference will be made to the operation of this industrial fryer, it being understood, however, that the level regulator can be used in other applications. It is intended, in this industrial fryer, that the frying tank, which is empty out of service, is supplied with hot oil from a buffer tank, each time a user orders a portion of fries. The hot oil is moved from the buffer tank to the frying tank by a piston. When the cooking is finished, the oil contained in the frying tank is evacuated from the latter by a conduit so that it does not mix with the hot oil contained in the buffer tank. It is important to maintain a constant level of hot oil in the buffer tank between each period of supply to the frying tank.

To do this, it is not possible to use a simple regulation system in the form of an inverted bottle which would contain an additional oil and whose free end of the neck would be flush with the desired level for the oil in the buffer tank. because this level is not stable: when the fryer is put out of service, the temperature of the oil in the buffer tank drops and the level drops. With a bottle-shaped level regulator reversed, the cold oil level would be reduced to the desired level for the hot oil and, when the machine ^'would be returned to service, the level of hot oil would exceed that he must be . - 2 -

We could solve the problem by providing a solenoid valve. However, any electrical or mechanical system that presents risks of failure and the present invention proposes to provide an extremely simple structure regulator involving only the laws of physics. ,

Thus, the regulator according to the invention comprises a chamber surmounting the tank and communicating with the latter by means, on the one hand, of an air intake tube which plunges into the tank up to the level which must be kept constant and, on the other hand, an inverted U-shaped tube with unequal branches, the short branch of which opens freely into the chamber, the long branch of which opens into the reservoir and the curved part of which is at a level below the periodic filling level of the tank, said chamber being surmounted by a reserve of fluid in the form of an inverted bottle, the neck of which plunges into the chamber.

Thanks to this arrangement, when the fluid which, in the chosen application example, is oil, is discharged from the reservoir towards the tank, its level rises above the curved part of the U-shaped tube inverted so that the fluid fills the chamber to a level higher than this curved part. When the fluid is evacuated from the tank, the regulator chamber partially empties, the level of fluid remaining in the chamber being controlled by the level of the free end of the neck of the fluid reserve.

If the oil level in the buffer tank is flush with the free end of the air intake tube, nothing happens because, in the absence of air penetration into the regulator chamber, the fluid contained in the tube in U inverted can not flow: this tube remains filled with fluid and the siphon which it constitutes is primed.

On the other hand, if the oil level in the buffer tank drops below the free end of the air intake tube, due to the consumption of oil, air enters the air intake tube. To restore the pressure in the regulator chamber, it is produces a siphon effect discharging a quantity of fluid from the regulator to the tank. As the fluid level drops in the regulator chamber, air enters the free end of the neck of the fluid reserve and the reserve oil flows into the regulator chamber.

The flow of oil from the regulator chamber to the reservoir is interrupted when the oil level in the chamber reaches the level at which the short branch of the inverted U-tube opens and the flow of the fluid contained in the reserve to the regulator chamber ceases when the oil level in the chamber again reaches the free end of the neck of the fluid reserve.

To prevent a DC current is established between the fluid supply and the drain that is the U-tube ^"inverted, it is advantageous that the neck-penetration zone of the fluid supply in the control chamber is isolated from the area occupied by the U-tube inverted by a perforated wall restricting the flow of fluid from one area to another. The regulator chamber is preferably provided, in, or in the vicinity of, its upper part, d '' a vent surmounted by a capillary tube to allow the air to escape from the chamber when the oil level rises there. Each time oil is filled, it enters the capillary tube and each time it is emptied, drops of oil remain there retained by capillary action, preventing any entry of air through the capillary tube into the chamber.

To prevent the oil discharged into the capillary tube from spilling out of the regulator, the end of the capillary tube, opposite the vent, opens into the tank. In this way, there is no need to provide a special collector.

The invention is described below with reference to the accompanying drawing in which: - Figures 1 to 3 show the regulator according to the invention in three operating phases, and

- Figure 4 shows the application of the regulator to the industrial fryer described in the application for French Patent No. 2,501,491 cited above.

If we refer first to Figure 4, we see a frying tank 1 having a side opening 2 hermetically closed by a pivoting door 3. A basket 4, adapted to receive the fries to be immersed in the frying oil, is made integral with the door 3 so that it pivots with the latter. The frying tank 1 surmounts a hot oil buffer tank 5 capable of being pushed back towards the tank 1, according to the white-headed arrows, under the effect of a pressure exerted by a piston not shown. This supply of the tank 1 is done each time a user orders a portion of fries. When the cooking is finished the oil contained in the frying tank is evacuated through a line 6 according to the arrow with black head.

For more details as to the operation and the "structure of the industrial fryer, reference may be made to the aforementioned patent application No. 2,501,491.

For the proper functioning of the fryer, it is important that the level h_ of the hot frying oil in the tank 5 remains constant.

To do this, according to the present invention, there is provided a level regulator designated as a whole by the reference 7 in FIG. 4 "The level regulator consists of a chamber 8 and an oil reserve 9, which have been shown joined to FIG. 4 and separated from FIGS. 1 to 3 •

If we now refer to these Figures 1 to 3, where the regulator is shown on a larger scale, and where the tank 1 is shown schematically only by the column l ', we see that the chamber 8 contains a tube air intake 10 and an inverted U-shaped tube 11 with uneven branches serving as a siphon. The tube 10 opens into the tank 5 at level h which is the desired level for the hot oil in this tank. The short branch of the inverted U-tube opens into the regulator chamber at level h. which is the minimum filling level of the chamber 8, and the neck 12 of the reserve 9 in the form of an inverted bottle opens into the room 8 at level h_ ₂ which is the level below which reserve 9 ensures complementarization.

The penetration zone of the neck 12 in the chamber 8 is separated from the zone occupied by the inverted U-tube 11 by a wall 13 having an opening 14 restricting the passage of the oil from the reserve 9 towards the siphon that

1 constitutes the tube 11.

Figure 1 shows the situation when the column 1 ', symbolizing the frying tank 1, is filled with oil. _Q In this case, the oil fills the chamber 8 and its level is higher than the level of the curved portion of the tube inverted U

11. The elevation of the oil in the chamber 8 would be limited by the volume of trapped and compressed air between the oil and the upper wall of the chamber 8, if there were no means allowing the evacuation of this air. These means can be constituted by a vent 15 provided with a valve or, better, with a capillary tube 16 going from the upper wall of the chamber 8 to the column 1 '. When column 1 is filled with oil, the capillary tube 16 is also filled with oil.

When the column l 'is emptied (Figure 2), the oil level drops in the tank 5 and the capillary tube 16 is emptied, drops of oil remaining there, however retained by capillarity and closing it, so that the air from the column l 'cannot enter the chamber 8 via the capillary tube 16. If the level of the oil in the tank is not lower than the level h_, the oil in the tank 5 plugs the free end of the air intake tube 10, which prevents any penetration of air into the chamber 8. It follows that the oil contained in the siphon 11 cannot flow and that the siphon remains primed.

As long as the level of the oil in the reservoir 5 does not drop below h_, the situation in the level regulator changes alternately from the representation of FIG. 1 to the representation of FIG. 2, each time column 1 'is filled and emptied.

However, if the oil level in the tank 5 fall below h, as is the case in FIG. 3, air enters the air intake tube 10, according to the white-headed arrows and, by siphoning, the oil contained in the chamber 8 passes from this chamber into the reservoir 5 according to the black-headed arrows represented in the siphon 11. As a result, the level of the oil in the chamber 8 decreases and the air enters the reserve 9 • I It follows that oil from this reserve flows into the chamber 8. The siphoning is interrupted when the level of the oil in the chamber 8 reaches h and the complementarization carried out by the oil reserve 9 ceases when the level of oil, in chamber 8, joins h_.

The function of the perforated wall 13 is to restrict the passage of the oil from the reserve 9 to the siphon 11 to prevent it from establishing a direct current between them. It is clear that the defusing of the siphon 11 interrupts the complementarization of oil from the reservoir 5 and that the re-establishment of the level h_ may require several re-primings of the siphon. However, the siphon can only be re - primed if the column is refilled. Thanks to this arrangement, it is excluded that the lowering of the oil level in the buffer tank 5 _? following the stopping of the machine, leads to an undesirable complementarization of the oil level in the buffer tank as a result of the cooling of the mass of oil which it contains, the regulator being neutralized due to its absence of reboot.

Claims

CLAIMS 1 - Level regulator adapted to maintain constant the level of a fluid in a reservoir supplying periodically a tank which overcomes it and which is emptied after each supply, said regulator being characterized in that it comprises a chamber (8 ₍ ) closed also overcoming the reservoir (5) and communicating with the latter by means, on the one hand, of an air intake tube (10) which plunges into the reservoir (5) up to the level h_ to be kept constant and, on the other hand, an inverted U-tube (il) with uneven branches, the short branch of which opens freely into the chamber (8), the long branch of which opens into the reservoir (5) and the part of which curve is at a level below the level of periodic filling of the tank (1 '), said chamber (8) being surmounted by a reserve of fluid (9) in the form of an inverted bottle whose neck (12) plunges into the chamber ( 8).

2 - Regulator according to claim 1, characterized in that the region of penetration of the neck (12) of the fluid reserve (9) in the chamber (8) is isolated from the area occupied by the inverted U-tube (it) by a perforated wall (1 3 _} 14) restricting the flow of fluid from one zone to another.

3 - Regulator according to claim 1 or 2, characterized in that the chamber (8) has in, or in the vicinity of, its upper wall a vent (15) surmounted by a capillary tube (lό).

4 - Regulator according to claim 3 _> characterized in that, at its end opposite to the vent (15) _> the capillary tube (16) opens into the tank (l ').

5 - Regulator according to any one of claims 1 to 4, characterized in that it is applied to maintain constant the level h of hot oil in a buffer tank (5) periodically supplying a frying tank (1) which overcomes it and which is emptied after each feeding.