[0001] The present invention relates to an apparatus for effecting the cleaning of plants
for the delivery of liquid or pasty food products, products that may include drinks,
ice creams, creams or the like that are delivered through a suitable delivery tap.
[0002] A similar device is already known from the European Patent n°. EP-B1-0245641, in
which a machine intended for the delivery of food products is described, to which
is associated an apparatus that allows the sterilisation and the washing of the delivery
tap to be effected.
[0003] The apparatus described in the cited European Patent comprises a boiler for the production
of hot water or steam which is then transferred to the delivery tap of the food products
under the control of a timer, which controls the cycle of operation of the apparatus
at pre-set times. There are particular safety devices used to control the correct
operation of the apparatus that have the purpose of interrupting the operation of
the boiler in case the labyrinth of tubes in the boiler is obstructed at any point,
for instance by the formation of calcium deposits or other types of scalings.
[0004] One of the main drawbacks of a similar device is due to the particular complexity
of the safety systems that must be provided in order to prevent breakdowns or, still
worse, situations of danger due to the excess of pressure that could develop inside
the boiler. The safety and control systems comprise in this case at least one flow
rate regulator connected to the water supply pipe and at least one pressure switch
arranged between the metering solenoid valve and the boiler. The pressure switch has
the function of interrupting the operation of the boiler in case a particularly high
pressure is reached between the metering solenoid valve, which closes after admitting
a predetermined quantity of water, and the boiler.
[0005] Besides having a high cost, a similar system has also shown itself lacking the necessary
reliability demanded by operators in the sector. For instance, since the cycle of
cleaning and sterilisation is normally effected in the operator's absence during normal
closing hours of premises, the occurrence of a slight obstruction in the tubes of
the boiler doesn't cause any damage, thanks to the complex safety system, but effectively
prevents efficient cleaning and sterilisation of the delivery tap. This fact may not
be readily immediately noticed by the operator, who continues to enable the timed
operation of the apparatus without becoming effectively aware that the cycle of cleaning
and sterilisation has not been completed or hasn't been effected at all.
[0006] The object of the present invention is to produce an apparatus for cleaning plants
for food product delivery that is particularly simple to construct, that has particularly
limited costs and dimensions, and that could be easily integrated into new plants,
as well as into existing plants.
[0007] Another object of the present invention is to produce an apparatus of the type described
above that is particularly reliable and that requires limited maintenance.
[0008] These objects are achieved by the present invention which relates to an apparatus
for cleaning a plant for the delivery of a liquid or a pasty product, the plant comprising
at least one delivery tap for one or more products, the apparatus further comprising
at least one water supply pipe for water drawn from a supply source, at least one
steam generator device fed with water from the supply pipe, means for controlling
the production of steam in the steam generator device, at least one conduit to convey
the steam to at least one delivery tap of the plant and means for timing the operation
of the apparatus, characterised in that the device for the generation of steam is
an instantaneous generator of steam and that the means for controlling the generation
of steam comprises a pressure reducer located along the supply pipe upstream of the
steam generator.
[0009] The combination of a simple pressure reducer with an instant steam generator eliminates
the need for all the safety devices used in the apparatuses of known type. In fact,
an instant steam generator comprises in practice a single straight pipe having a particularly
large section, in which entering water is brought quickly to such a temperature as
to change it completely into steam before if reaches the other end of the generator.
There can't, therefore, be any problem of obstruction in the single duct. Therefore,
using a metering solenoid valve controlled in the way already known from the cited
European Patent, it is sufficient to maintain constant the supply pressure of the
water upstream of the boiler, using for that purpose an appropriately set pressure
reducer, to obtain particularly reliable operation from the apparatus.
[0010] The pressure reducer upstream of the instant steam generator is set up to deliver
water at a pressure between about 0.5 and 2 bar and, preferably, at a pressure of
about 1.5 bar.
[0011] The apparatus is provided with a metering solenoid valve located along the supply
pipe between the pressure reducer and the instant steam generator. In this way, knowing
the pressure set at the pressure reducer, it is possible to set up the opening and
closing cycles of the metering solenoid valve to establish the quantity of water arriving
at the instant steam generator and therefore the quantity of steam necessary to achieve
an effective cleaning and/or sterilisation of the delivery tap.
[0012] It is possible, if necessary, to insert on anti-calcium filter located along the
supply pipe between the pressure reducer and the metering solenoid valve. This prevents
possible formation of calcareous deposits in the circuit, above all in correspondence
of the metering solenoid valve and in the connecting pipe to the instant steam generator
in case the apparatus is used with particularly hard water.
[0013] The present invention will now be described, by way of example and without limiting
purposes, with reference to an embodiment illustrated in the attached drawings, in
which:
- Figure 1 illustrates the hydraulic circuit of the apparatus according to the present
invention;
- Figure 2 illustrates the electrical circuit of the apparatus according to the present
invention; and
- Figure 3 is an exploded perspective view of some elements of the apparatus according
to the present invention.
[0014] With reference to the hydraulic circuit shown in Figure 1, it should be noticed that
the apparatus according to the present invention comprises essentially a pressure
regulator 1 to which water deriving from the water pipe network is delivered through
a supply pipe 2.
[0015] The water leaving pressure reducer 1 is taken through a pipe 3 to a metering solenoid
valve 4, if necessary interposing an anti-calcium filter 40 (here shown with broken
line) that prevents the possible deposit of scalings, above all in pipe 3 and in solenoid
valve 4.
[0016] The water leaving the solenoid valve 4 is taken by means of a pipe 5 to an instant
steam generator 6, which delivers steam to an exit duct 10 that will carry it directly
to one or more taps of the food product delivery plant (not shown).
[0017] Steam generator 6 is equipped in particular with a heating element 7 and a pair of
temperature-sensitive devices 8 and 9 that will be described in more detail below.
[0018] The electric circuit of the apparatus shown in Figure 2 comprises a control circuit
20 that acts on the solenoid valve 4 to regulate the cycle of cleaning and sterilisation.
In particular, circuit 20 comprises a timer which activates the solenoid valve 4 for
a predetermined period with a series of opening and closing cycles (ON and OFF states).
Maintaining the pressure upstream of solenoid valve 4 constant, it is thus possible
to dose the quantity of water to be transformed into steam with high precision. Knowing
that the period of the pulsating signal controlling the solenoid valve is pre-set
generally to one second, it is possible to regulate the quantity of water fed to the
steam generator on the basis of the number of ON states of the solenoid valve that
occur for the whole duration of the cleaning cycle.
[0019] The supply to heating element 7 of steam generator 6, as well as being subject to
control circuit 20, is also subjected to the control of temperature-sensitive devices
8 and 9. Device 8 consists preferably of a normally-open thermostat that closes the
electric circuit to which if is connected when temperature exceeds a pre-set threshold,
for instance between 120 °C and 130 °C. Device 9, on the other hand, consists preferably
of a normally closed thermostat, provided with a reset switch, that opens the circuit
to which it is connected when the temperature exceeds a pre-set threshold, for instance
between 160 °C and 170 °C.
[0020] The activation of the apparatus can be effected manually by means of a button 21
each time it is deemed necessary, or can be regulated by a programmable timer 22 that
daily activates the cycle of cleaning and sterilisation during the closing hours of
the place in which the delivery plant is installed.
[0021] As it is evident from Figure 3, the apparatus is housed in a cabinet 50 that can
be mounted on the delivery plant which is to be cleaned, or it can be an integral
part of the same plant. The cabinet 50 comprises one or more detachable cover panels
(not shown) to allow access to the inside.
[0022] Switch 21 is shown for clarity as located on the outside of chassis 50, but it is
preferably located inside cabinet 50 with only the button itself accessible from the
outside.
[0023] The water inlet consists of a suitable pipe (not shown) attached to a link for flexible
pipes 51 that protrudes from cabinet 50. The water supply circuit continues via a
union elbow 52 connected in turn to pressure reducer 1, the latter provided with a
manometer 11 that indicates the pressure setting. Pressure reducer 1 allows the pressure
to be maintained between about 0.5 and 2 bar, and is preferably maintained at about
1.5 bar.
[0024] The outlet of pressure reducer 1 is connected to the entry of metering solenoid valve
4 by means of a duct 3 and a pair of pipe fittings 31 and 32 respectively. The connection
between the outlet of the metering solenoid valve 4 and the inlet of steam generator
6 is via linking pipe 5.
[0025] In the body of steam generator 6 are housed heating element 7 and two temperature-sensitive
devices 8 and 9 already described above. Device 9 is preferably provided with a RESET
button 91 that allows its re-activation in the case where the temperature inside steam
generator 6 has exceeded a pre-set safety threshold.
[0026] Outlet aperture 61 of steam generator 6 receives a union elbow 62 that is connected
to pipe fitting 63 for flexible pipes. To this pipe fitting 63, protruding outside
cabinet 50, is connected a pipe (not shown) that carries the steam to one or more
taps of the drinks delivery plant.
[0027] Inside cabinet 50 are further housed control circuit 20 and all the electric wiring
(not shown) between the various components of the apparatus, as well as any timer
22 and any anti-calcium filter 40 (not shown in Figure 3). The filter could, for instance,
be inserted directly in place of duct 3 or inserted along the same duct, or yet again
between pipe fitting 32 and the metering solenoid valve.
1. Apparatus for cleaning a plant for the delivery of a liquid or a pasty product, said
plant comprising at least one delivery tap for one or more of said products, the apparatus
further comprising at least one water supply pipe for water drawn from a supply source,
at least one steam generator device fed with water from said supply pipe, means for
controlling the production of steam in said steam generator device, at least one conduit
to convey said steam to said at least one delivery tap of said plant and means for
timing the operation of the apparatus, characterised in that said device for the generation
of steam is an instantaneous generator of steam and that said means for controlling
the generation of steam comprises a pressure reducer located along said supply pipe
upstream of said generator of steam.
2. Apparatus according to Claim 1, characterised in that said pressure reducer is set
up to deliver water to said instant steam generator at a pressure between about 0.5
and 2 bar.
3. Apparatus according to Claim 2, characterised in that said pressure reducer is set
up to deliver water to said instant steam generator at a pressure of about 1.5 bar.
4. Apparatus according to Claim 1, characterised in that said means for controlling the
generation of steam comprises at least one metering solenoid valve located along said
supply conduit between said pressure reducer and said instant steam generator.
5. Apparatus according to Claim 1, characterised in that it comprises at least one sensor
for detecting the temperature in said instant steam generator.
6. Apparatus according to Claim 1, characterised in that it comprises at least one thermostat
to interrupt the power supply to the heating element enclosed of said instant steam
generator in case a pre-set temperature is exceeded.
7. Apparatus according to Claim 1, characterised in that it comprises at least one anti-calcium
filter disposed along said supply conduit between said pressure reducer and said solenoid
valve.