FR2799396A1 - Mechanism for washing tanks containing milk, wine or blood comprises washing product inlet casing connected by rotating seal to rotating tube of the stirring arm - Google Patents

Abstract

Washing mechanism is mounted on the stirring device and comprises an inlet casing (12) with a feeding pipe (13) on top of the rotating tube (4) of the stirring arm (2). A rotating seal (25) has a part (26) integral with the tube and one (27) integral with the casing that slides along the axis when the washing product pressure in the casing reach a threshold. The seal is formed and the liquid travels along the tube to be sprayed through the nozzles (10).

Description

The present invention relates to the installation for washing tanks such as, for example, tanks used for the storage and cooling of milk on the farm or, in general, in the food industry for the conservation and heat treatment of liquids such as milk, wine, blood, etc ...

These installations for washing the internal space of the tank are generally associated with the device for stirring the liquid contained in the tank, which stirring device comprises a system of blades which are carried by arms in the form of a tube or an axis. hollow, which arm is driven by means of a gearmotor arranged at the top of the tank.

Actually agitator device is used to perform, after emptying the tank, washing operation by spraying a washing agent using the agitator tube and the blades provided for this purpose with orifices for diffusing said agent, - say water or a washing solution, in the tank, in order to remove any possible deposits, which are in particular in the case of milk likely to promote the development of germs or others.

The use of the agitator to carry out the washing makes it possible to reduce the presence of accessories in the tank and therefore to reduce the risks of pollution by these accessories.

In addition, the fact of concentrating both agitation and washing on the same assembly makes it possible to achieve significant savings in manufacturing and also in assembly.

However, the washing circuit requires a seal between the agent arrival and the agitator tube. This seal is only useful during the washing operation and, in the systems currently used, there is a rapid deterioration of this seal due to its dry operation most of the time.

This deterioration causes leaks and infiltration of the washing agent in the gear motor, and even in the electrical part, that is to say of the motor itself. In addition, the presence of a seal can cause water retention which, in frost, causes rapid deterioration of the seal due to the presence of ice.

The object of the present invention is to make modifications to this joint system in order to eliminate the drawbacks encountered in existing installations.

The installation according to the invention comprises, between the inlet housing of the washing agent, which is integral with the gear motor housing and the upper end of the agitator tube which is driven by said gear motor, a rotary joint of the disengageable type , and means for implementing said seal during and only during the washing operation.

According to the invention, this physical separation of the two parts forming a seal makes it possible to avoid wear. The seal only works when the washing installation is under pressure, that is to say in the presence of a liquid phase, will lubricate the surfaces in contact and in movement, thus preventing their deterioration.

According to another arrangement of the invention, the seal comprises, on the one hand, a ring integral with the upper end of the tube, mounted in leaktight manner above said end by means of an appropriate support bushing and, on the other hand, a ring immobilized in rotation, located above said tube, centered on the axis of the latter, which is carried by a crew which is secured to the inlet box of the washing agent, in a sealed manner and which is axially movable under the effect of any hydraulic, mechanical, pneumatic, electric declutching system or a combination of these systems and, preferably, under the effect of the pressure of the washing agent in the inlet housing, which crew is movable over a distance which makes it possible to pass the ring from an inactive sealing position to an active position in contact with the rotating ring, and vice versa.

According to another arrangement of the invention, the seal ring, located at the end of the agitator tube, is a ring made of ceramic material and a ring secured to the inlet housing of the washing agent is made of material of the graphite type. According to another arrangement of the invention, the movable assembly carrying the graphite ring consists of a support plate acting as a piston, which is guided axially with respect to the inlet housing, - a membrane providing sealing between said housing and said plate, - elastic means for returning the latter to the inactive sealing position.

Still according to the invention, the elastic return means the support plate of the graphite ring, consist of lamellae which 'extend radially under said plate, acting as return spring.

According to another arrangement of the invention, the ring-holder plate comprises a tubular central part on which said ring is centered, which tubular central part projects in relation to the latter so as to guide the washing agent towards the entry of the tube, the internal diameter of the latter being greater than the diameter of passage of the washing agent in said tubular central part.

Still according to the invention, a cover acting as a deflector and a sealing member is fixed to the end of the agitator tube, covering the top of the gearmotor housing around said tube in order to avoid any penetration of water or another in said housing at the outlet of the tube on the upper surface of the housing.

According to another arrangement of the invention, the space around the sealing rings is masked by a foam-shaped protective lining which prevents the entry of insects or the like.

The invention will be further detailed with the aid of the following description in conjunction with the appended drawing which shows, in section and schematically, the installation for washing a tank.

The tank 1, of which only a portion of the upper part appears, is equipped with an agitator device 2 which comprises blades mounted at the lower end of a vertical tube 4, which tube is rotated by means of a device geared motor 5 which is appropriately fixed on the upper part of tank 1.

The output shaft 6 of the gearmotor 5 is in the form of a sleeve into which the tube 4 which forms the agitator arm is inserted. This tube 4 comprises a flange 7 which acts as a stop and which comes to bear on the lower end of the sleeve 6. The upper end of the tube 4 has a thread which makes it possible to lock said tube on the sleeve 6, so as to allow its rotational drive by means of the gearmotor.

The tube 4 also serves as a conduit for conveying an appropriate washing, rinsing, etc. agent into the tank. The blades 3 are fitted for this purpose and include, for example, nozzles or nozzles 10 oriented in different ways to spray the washing agent wherever necessary in the tank in order to eliminate traces of products and deposits.

The upper part 11 of the tube 4 is surmounted by a housing 12 which serves to supply the washing agent. This box 12 is connected, by circuit not shown, to a pump which makes it possible to supply this washing installation under pressure.

The shoemaker 12 forms a kind of cap situated above the upper part 1 of the tube 4 with an inlet 13 arranged radially in the figure, relative to the vertical axis 14 of the installation. The cap 12 has a base 15 and this base is fixed to the casing 16 of the gearmotor by means of tie rods 17.

The space between - the base 15 of the housing 12, - the upper part 16 of the geared motor housing, and - the tie rods 17 which are arranged in a circular fashion around the axis delimits an area in which all the necessary elements are found to achieve the seal between the arrival of the washing agent at the housing 12 and the tube 4 as well as the seal and protection of the upper outlet of the sleeve 6, area where, traditionally, observes infiltration of the agent washing in the casing of the gearmotor 5 destroying the mechanism even sometimes the electrical part, that is to say the electric drive motor.

The outlet of the sleeve 6 is protected by a deflector 20 which covers the upper part 21 of the casing 16. This deflector 20 made for example of rubber, is in the form of a cup tightly fixed on the upper part of the sleeve 6 , under the nut 9 which makes it possible to fix the tube 4 on said sleeve 6. The domed upper part of this deflector 20 allows the outward flow of any fluid liable to fall on the casing 16. The space between the deflector 20 and the upper part 21 of the casing 16 arranged in the form of baffles, forming a sort of step in radial section so as to avoid any untimely penetration of water or washing agent in the event of spraying.

The seal marked globally 25, between the housing 12 and the upper part 11 of the tube 4 is of the disengageable type, that is to say that this seal is put into service, in the active sealing position, during and only when passing the washing agent.

seal 25 includes a rotating part 26 secured to the tube 4 a secured portion 27 of the housing 12, immobilized in rotation but capable of moving axially along the axis 14 of the installation in order to apply said rotating part 26 and produce sealing.

The rotating part 26 of the seal comprises an annular ring made of ceramic material. This ring is housed in a support sleeve which is itself fixed to the end 11 of the tube 4, screwed onto this end immobilized in an appropriate manner, for example by a needle 31.

Part 27 of the joint forms a sort of assembly which is axially movable. This part 27 comprises a ring 32 centered on the axis 14. This ring 32 is for example made of softer material, of the graphite type, self-lubricating, and it is movable to apply to the upper surface of the ceramic ring 29.

This ring 32 is integral with a support plate 34 which is made in one piece, a central tube 35 arranged axially and a flange which extends under the housing. This plate 34 is movable vertically, centered on the axis 14, guided in a sort of crown 37 fixed under the base 15 housing made, this support plate 34 forms a kind of piston which is guided axially and which makes it possible to move the ring graphite 32 between an inactive sealing position as shown in the figure and an active sealing position to place it in contact with the ceramic ring 29.

displacement of the support plate 34 is effected by any suitable means, hydraulic, pneumatic, mechanical, electrical or any combination. Preferably, this support moves automatically under the effect of the pressure prevailing in the housing 12 when the washing agent is put into circulation. The diameter D of the passage of the washing agent in the support plate 34, and in particular in the tube 35, is substantially less than the internal diameter of the tube 4.

The seal between the support plate 34 and the base 5 of the housing 12 is produced by means of a membrane or plate 37 made of an appropriate material of the rubber type. This plate 39 is pinched between the crown 37 and the base and, at the level of the support plate 34, the sealing and the fixing are effected by means of a washer 40 with screws 41 cooperating with said plate.

The support plate 34 is kept in the inactive position by means of elastic members 42 which extend radially, fixed under the crown 37. This crown 37 is fixed to the base 15 by the bolts. It is noted that the tubular central part 35 of the support plate 34 extends towards the tube 4 forming a sort of injector whose diameter is less than that of the said tube 4. This tube 35 extends as far as the ring 29. This produces a kind of baffle at the level of the space between the ring 29 and the ring 33.

In the inactive sealing position, the internal space of the tank is placed in communication with the outside, which avoids any risk of accidental siphoning of the washing agent in the event of the tank emptying.

It is also noted that the installation of the ring 29 is such that it avoids any retention of water in the part 26 of the seal, which has the advantage of eliminating any risk of freezing at the level of said seal.

The space between the sealing rings 29 and 32 is permanently masked by a protective lining made of foam.

This protective lining is for example made up, as shown in dotted lines in the main figure, of a kind of skirt 45 which is tightened on the ring 32 and slides on the support bush 30 of the ring 29.

In the partial diagram separately, the protective lining consists of a socket 46, fixed between two flanges 47 and 49, the spacing of which is maintained by means of sockets 50 disposed at the level of the fixing bolts 43 '. The foam constituting the socket 46 slides on the socket 30 which rotates with the agitator arm.

The housing 12 also contains a water filter 51.

Claims (1)

- CLAIMS - 1.- Installation for washing the internal space of a tank (1), associated with the device for stirring the product contained in said tank which installation includes a box (12) for supplying the washing, which housing is connected to the upper end of the agitating arm (2), which arm consists of a vertical tube in which said washing agent circulates, a seal provides sealing between, on the one hand, the end (11) of the movable tube (4), driven by a geared motor (5) fixed on top of the tank, and, on the other hand, the housing (12) which is fixed, integral with the casing (16) of said gear motor, characterized in that it comprises a rotary joint (25) of the disengageable type and means for implementing said joint during and only during the washing operation. 2.- washing installation according to claim 1, characterized in that the seal (25) comprises, on the one hand, a ring (29) integral with the end (11) of the tube (4), mounted in leaktight manner above said end by means of a suitable support sleeve (30), and, on the other hand, a ring (33) situated above said tube, centered on the axis of the latter, which ring (33 ) is carried a crew (27) which is integral with the housing (12) in a sealed manner, and which moves axially under the effect of the pressure of the water in said housing, a distance which allows the ring (33) to go from an inactive sealing position to an active position in contact with the ring 29 and vice versa. 3. Washing installation according to claim 2, characterized in that the ring (29) located at the end of the tube (4) is a ring made of ceramic material and in that the ring (33) of the housing (12) is made of graphite material. 4. Washing installation according to any one of claims 2 or 3, characterized in that the movable assembly (27) consists of - a support plate (34) acting as a piston, on which the ring is fixed ( 33), which plate is axially guided relative to the housing (12), - a membrane (39) sealing between said housing and said plate, - elastic means (42) for returning the latter to the inactive position sealing. 5. A washing installation according to claim 4, characterized in that the elastic return means (42) extend radially under the support plate (34), fixed under the base (15) of the housing (12). 6.- washing installation according to any one of claims 2 to 5, characterized in that the support plate (34) has a central tubular part (35) which is centered on the ring (33), which part (35) extends projecting from the latter so as to guide the rinsing fluid into the inlet of the tube (4), forming a sort of injector whose diameter is substantially less than the diameter of the tube (4). 7.- washing installation according to any one of claims 1 to 6, characterized in that the upper part of the gear motor housing, at the outlet of the tube (4), is capped by a deflector (20) mounted tightly on the end of said tube, which deflector eliminates the risk of water or other infiltration at said outlet. 8. A washing installation according to any one of claims 1 to 7, characterized in that it comprises, around the support sleeve (30), a protective lining forming a filter to prevent any risk of introduction of dust, insects or others, which lining is fixed by any suitable means to the fixed part of the installation, that is to say the water inlet box or the housing of the reducer or the like.