FR2758690A1 - ANTI-FOAM DEVICE FOR A SPRAYER, ESPECIALLY AGRICULTURAL - Google Patents

Abstract

Anti-foam device for sprayer, in particular agricultural. The invention relates to a device for preventing the formation of foam in the main tank of a sprayer, in particular agricultural. The return of the liquid to the main tank (1) is effected by a device (11) which has a large number of separate small orifices (12) which return the excess liquid to the main tank at low pressure and in the form a multitude of low speed jets.

Description

The present invention relates to an anti-foam device

  for sprayer, especially agricultural.

  It is known that it is necessary to treat the crops by spraying on the soil or on the plants liquids of various kinds in the form of fog or fine droplets. Spraying devices of known types generally comprise a vessel from which the liquid to be sprayed is taken to send it under a pressure in pipes which lead to

spray nozzles.

  Generally, in order to ensure sufficient pressure at the spray nozzles, a pump is used which has a flow rate which is much greater than the flow rate of the spray nozzles, the excess liquid being recycled back into the main liquid tank via a valve calibrated according to the pressure at which it is desired

spray.

  In a number of cases, the liquid thus brought back to the main tank has a pronounced propensity to form foam which accumulates therein which constitutes a significant inconvenience when it is necessary to

refill the tank.

  The present invention aims to eliminate this disadvantage.

  The present invention relates to a device for preventing the formation of foam in the main tank of a sprayer, in particular an agricultural sprayer, which is characterized in that the return of the liquid in the main tank is carried out by a device which comprises a large number of small, distinct orifices that cause the excess liquid to fall into the main reservoir at low pressure and under

  the shape of a multitude of jets at low speed.

  This multitude of jets can be obtained, either with one or more dispensers of the genus pot d'arrosoir which have a large number of small orifices on a large surface, or in the form of ramps which comprise a large number of small holes arranged in line

  possibly being grouped together several by far.

  In a variant, it is possible to make at the upper part of the tank a chamber whose bottom wall has a large number of small holes and into which the recycled liquid is sent so that it falls into the main tank under the form

a fine rain.

  - 2 - According to the invention, it is necessary that the total section of small holes is sufficient for the jets of the liquid

  ebbing into the main tank is carried out at low speed.

  It can be seen that, thanks to the invention, the recycling of the liquid in the main tank takes place without any notable formation of foam, which makes it possible to have a good visibility of the contents of the tank at all times and to allow its filling without being embarrassed by the foam that

  is formed with the known devices.

  In the case where the recycling of the excess liquid is used to stir the liquid that is in the tank to maintain its homogeneity, it is appropriate according to the invention to divide the recycled liquid into two streams, one being sent into the main tank for homogenization, while the other is sent into the antifoam device according to the invention. In order to better understand the invention, will now be described by way of illustration and without any limiting character an embodiment taken as an example and shown in the drawing, the single figure shows a schematic view of a device of

  agricultural spraying according to the invention.

  We see in the single figure the main tank 1 containing the spraying liquid 2. It is schematically represented by a line

  interrupted 3 a running gear that supports the tank 1.

  At the lower part of the tank 2, there is a pump 4 sending under pressure in the pipe 5 the spraying liquid which ends in a ramp 6 disposed perpendicularly to the plane of the figure, this ramp 6 comprises a plurality of nozzles which send jets 7 of

  fine droplets towards the plants 8 which are arranged on the ground.

  Line 9 returns to the main tank 2 the excess of

  liquid that is not distributed through the spray nozzles 6.

  The spray pressure is determined by a suitable discharge valve calibrated to open only when the pressure in

  Line 5 exceeds the desired value.

  There is schematically shown inside the tank 1, a ramp 11, provided with orifices 12 which make the liquid flowing back into the tank 1 falls without significant pressure and velocity in the form of a fine rain, which prevents the formation of foam inside the tank. Alternatively, the ramp 11 may be replaced by a plurality of sprinkler heads which have on a relatively large surface a large number of small holes so as to spray the liquid which

  flows back without giving it pressure and speed.

  It is understood that the embodiment which has been described above is not limiting and it can receive any desirable modifications without departing from the scope of the invention. In particular, it is clear that the embodiment which has been shown in the drawing is purely schematic and that the various organs

  can be made in different forms and positions.

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Claims (5)

  1. Device for preventing the formation of foam in the main tank of a sprayer, in particular an agricultural sprayer, characterized in that the return of the liquid in the main tank (1) is carried out by a device (11) which comprises a a large number of small, distinct orifices (12) which bring the excess liquid back into the main reservoir at a low pressure and in the form of a multitude of jets of low speed.   2. Device according to claim 1, characterized in that the excess liquid is returned to the main tank (1) by at least one ramp which has a large number of small orifices (12) arranged in line or which are optionally grouped to many by far in the distance.   3. Device according to claim 1, characterized in that the excess liquid is returned to the main reservoir (1) via at least one distributor of the watering apple type which   has a large number of small holes on a large surface.   4. Device according to claim 1, characterized in that the liquid is returned to the main tank (1) via a chamber placed at the top of the tank and   having in its lower wall a large number of small holes.   5. Device according to any one of claims 1 to 4,   characterized in that only a portion of the recycled liquid is fed into the defoamer, the remainder being used to   homogenize the liquid contained in the main tank.