U.S. patent application number 13/125992 was filed with the patent office on 2011-08-25 for system for washing washware and method for operating a system of this type.
This patent application is currently assigned to PREMARK FEG L.L.C.. Invention is credited to Axel Beck, Dietrich Berner, Harald Disch, Ralf Hubner.
Application Number | 20110203616 13/125992 |
Document ID | / |
Family ID | 42105011 |
Filed Date | 2011-08-25 |
United States Patent
Application |
20110203616 |
Kind Code |
A1 |
Berner; Dietrich ; et
al. |
August 25, 2011 |
SYSTEM FOR WASHING WASHWARE AND METHOD FOR OPERATING A SYSTEM OF
THIS TYPE
Abstract
The invention relates to a dishwashing system (100) comprising
at least one conveyor system (101) for feeding washware to one
conveyor dishwasher (2, 2') and a conveyor system (101) for feeding
dishware to the at least one conveyor dishwasher (2, 2') In order
to further reduce the consumption of fresh water, chemicals and
energy during operation, the invention provides a washware detector
apparatus (51) which is designed to detect the number of units of
washware, which are fed to the at least one conveyor dishwasher (2,
2') with the aid of the conveyor system (101) per unit time, in a
prespecified or prespecifiable region of the conveyor system (101).
Furthermore, a control device (50) is provided which is designed to
select a predefined or predefinable treatment program.
Inventors: |
Berner; Dietrich;
(Waldstetten, DE) ; Disch; Harald; (Elzach,
DE) ; Hubner; Ralf; (Frankfurt, DE) ; Beck;
Axel; (Offenburg, DE) |
Assignee: |
PREMARK FEG L.L.C.
Wilmington
DE
|
Family ID: |
42105011 |
Appl. No.: |
13/125992 |
Filed: |
November 12, 2009 |
PCT Filed: |
November 12, 2009 |
PCT NO: |
PCT/US09/64112 |
371 Date: |
April 26, 2011 |
Current U.S.
Class: |
134/25.2 ;
134/61 |
Current CPC
Class: |
A47L 15/0047 20130101;
A47L 2401/04 20130101; A47L 2501/07 20130101; A47L 2501/01
20130101; A47L 2501/24 20130101; A47L 15/241 20130101; A47L 2501/10
20130101; A47L 15/247 20130101; A47L 15/4295 20130101; A47L 2501/30
20130101 |
Class at
Publication: |
134/25.2 ;
134/61 |
International
Class: |
A47L 15/42 20060101
A47L015/42 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 13, 2008 |
DE |
10 2008 057 178.4 |
Claims
1. System for washing washware, with the system having the
following: at least one conveyor dishwasher which has at least one
wash zone, at least one final-rinse zone and a transportation
apparatus for conveying washware through the zones; and a conveyor
system for feeding washware to the at least one conveyor
dishwasher, characterized in that a washware detector apparatus is
provided, which is designed to detect the number of units of
washware, which are fed to the at least one conveyor dishwasher
with the aid of the conveyor system per unit time, in a
prespecified or prespecifiable region of the conveyor system, and
in that a control device is provided, which is designed to
automatically select a predefined or predefinable treatment program
and set the process parameters associated with the selected
treatment program as a function of the detected number of units of
washware which are fed to the at least one conveyor dishwasher per
unit time for the at least one conveyor dishwasher.
2. System according to claim 1, with the washware detector
apparatus having at least one optically, inductively or
capacitively operating detector device which is designed to detect
the presence of washware in the prespecified or prespecifiable
region of the conveyor system, and with the conveyor system being
designed to feed the washware to at least one conveyor dishwasher
at a predefined or predefinable feed rate.
3. System according to claim 2, with the at least one detector
device being designed to detect the presence of individual trays,
individual dishes, individual pots and pans, individual glasses,
individual items of cutlery and/or individual containers.
4. System according to claim 2, with the control device being
designed to set the process parameters, which are associated with
the selected treatment program, with a time delay in the at least
one conveyor dishwasher, with the time delay depending on the
distance of the region of the conveyor system monitored by the
detector device from the at least one conveyor dishwasher and on
the feed rate at which the washware is fed to the at least one
conveyor dishwasher.
5. The system according to claim 1, with a pre-cleaning and/or
pre-sorting station further being provided between the conveyor
system and the at least one conveyor dishwasher for the purpose of
manually pre-clearing and/or pre-sorting washware which is fed by
the conveyor system.
6. System according to claim 1, with the control device being
designed to automatically set the transportation speed, at which
the washware is transported through zones of the at least one
conveyor dishwasher, to a predefined or predefinable value as a
function of the detected number of units of washware which are fed
to the at least one conveyor dishwasher per unit time; and/or the
control device being designed to automatically set a quantity of
wash liquid sprayed in the at least one wash zone per unit time to
a predefined or predefinable value as a function of the detected
number of units of washware which are fed to the at least one
conveyor dishwasher per unit time; and/or the control device being
designed to automatically set a quantity of final-rinse liquid
sprayed in the final-rinse zone of the at least one conveyor
dishwasher per unit time to a predefined or predefinable value as a
function of the detected number of units of washware which are fed
to the at least one conveyor dishwasher per unit time.
7. System according to claim 1, with the at least one conveyor
dishwasher having a pre-wash zone with pre-wash nozzles, and at
least one main-wash zone which is connected downstream of the
pre-wash zone and has main-wash nozzles; with the control device
being designed to automatically switch on or switch off the supply
of wash liquid to the pre-wash nozzles of the pre-wash zone as a
function of the detected number of units of washware which are fed
to the at least one conveyor dishwasher per unit time; and/or with
the control device being designed to automatically switch on or
switch off the supply of wash liquid to the main-wash nozzles of
the at least one main-wash zone as a function of the detected
number of units of washware which are fed to the at least one
conveyor dishwasher per unit time.
8. System according to claim 1, with the at least one conveyor
dishwasher having a drying zone, and with the control device being
designed to automatically select a predefined or predefinable
temperature value of an air stream used in the drying zone to dry
the washware and set the temperature of the air stream used for
drying purposes to the selected value as a function of the detected
number of units of washware which are fed to the at least one
conveyor dishwasher per unit time; and/or with the control device
being designed to automatically select a predefined or predefinable
value of a volumetric quantity of a drying-air stream circulating
in the drying zone for drying the washware per unit time and set
the volumetric quantity circulating per unit time to the selected
value as a function of the detected number of units of washware
which are fed to the at least one conveyor dishwasher per unit
time.
9. System according to claim 1, with the at least one conveyor
dishwasher having a first main-wash zone, with main-wash nozzles,
and a second main-wash zone, with main-wash nozzles, which is
connected downstream of the first main-wash zone; and with the
control device being designed to automatically switch on or switch
off either the supply of wash liquid to the main-wash nozzles of
the first main-wash zone or the supply of wash liquid to the
main-wash nozzles of the second main-wash zone as a function of the
detected number of units of washware which are fed to the at least
one conveyor dishwasher per unit time.
10. System according to claim 1, with a first conveyor dishwasher
being provided for washing dishes, pots and pans, glasses and
containers, and a second conveyor dishwasher being provided for
washing trays and items of cutlery.
11. System according to claim 10, with the control device being
designed to automatically select a predefined or predefinable
treatment program and set the process parameters associated with
the selected treatment program in the at least one conveyor
dishwasher as a function of the detected number of units of
washware which are fed per unit time for at least one of the two
conveyor dishwashers.
12. System according to claim 1, with the control device being
designed to selectively automatically select a predefined or
predefinable treatment program for at least one conveyor dishwasher
and set the process parameters associated with the selected
treatment program in the at least one conveyor dishwasher as a
function of the detected number of units of washware which are fed
per unit time.
13. Method for washing washware, in which method washware is
conveyed to a conveyor dishwasher, which is designed in the form of
a rack-conveyor dishwasher or flight-type dishwasher, with the aid
of a conveyor system, with the conveyor dishwasher having at least
one wash zone, at least one final-rinse zone and a transportation
apparatus with which the washware is conveyed through the zones,
characterized in that the method has the following methods steps:
a) the number of units of washware which are fed to the conveyor
dishwasher with the aid of the conveyor system per unit time is
detected with the aid of a washware detector apparatus in a
prespecified or prespecifiable region of the conveyor system; and
b) a predefined or predefinable treatment program is automatically
selected and the process parameters associated with the selected
treatment program are set in the conveyor dishwasher as a function
of the detected number of units of washware which are fed to the
conveyor dishwasher per unit time.
14. Method according to claim 13, with the transportation speed at
which the washware is transported through the zones of the conveyor
dishwasher being automatically set to a predefined or predefinable
value as a function of a predefined or predefinable number of units
of washware which are fed to the conveyor dishwasher with the aid
of the conveyor system per unit time; and/or with a quantity of
wash liquid which is sprayed in the at least one wash zone per unit
time being automatically set to a predefined or predefinable value
as a function of a predefined or predefinable number of units of
washware which are fed to the conveyor dishwasher with the aid of
the conveyor system per unit time; and/or with a quantity of
final-rinse liquid which is sprayed in the final-rinse zone of the
at least one conveyor dishwasher per unit time being automatically
set to a predefined or predefinable value as a function of a
predefined or predefinable number of units of washware which are
fed to the conveyor dishwasher with the aid of the conveyor system
per unit time.
15. Method according to claim 13, with the process parameters of a
first treatment program being automatically set up to a predefined
or predefinable number of units of washware which are fed with the
aid of the conveyor system per unit time in the conveyor
dishwasher; and with the process parameters of a second treatment
program being automatically set when the predefined or predefinable
number of units of washware which are fed with the aid of the
conveyor system per unit time in the conveyor dishwasher is
exceeded.
16. Method according to claim 15, with the settable process
parameters including at least one of the following parameters: the
transportation speed at which the washware is transported through
the zones of the conveyor dishwasher; the quantity of wash liquid
sprayed in the at least one wash zone per unit time; the quantity
of final-rinse liquid sprayed in the at least one final-rinse zone
per unit time; the temperature value of an air stream used to dry
the washware in a drying zone of the at least one conveyor
dishwasher; and the volumetric quantity of a drying-air stream
circulating in a drying zone of the at least one conveyor
dishwasher for drying the washware per unit time.
17. Method according to one of claim 16, with the transportation
speed at which the washware is transported through the individual
treatment zones of the conveyor dishwasher, the quantity of wash
liquid sprayed in the at least one wash zone per unit time, and the
quantity of final-rinse liquid sprayed in the at least one
final-rinse zone per unit time are in each case automatically
increased when a predefined or predefinable number of units of
washware which are fed with the aid of the conveyor system per unit
time is exceeded in the conveyor dishwasher.
Description
[0001] The invention relates to a system for washing washware,
comprising at least one conveyor dishwasher having at least one
wash zone, at least one final-rinse zone and a transportation
apparatus for transporting washware through the individual
treatment zones of the conveyor dishwasher, and a conveyor system
for feeding washware to the at least one conveyor dishwasher. The
invention also relates to a method for operating a dishwashing
system of this type.
[0002] The invention accordingly relates, in particular, to a
dishwashing system having a flight-type dishwasher (flight-type
warewasher) or a rack-conveyor dishwasher (rack-conveyor
warewasher), in which the washware to be treated, for example
dishes, pots and pans, glasses, cutlery, trays and other utensils
to be cleaned, is fed to the conveyor dishwasher with the aid of a
conveyor system.
[0003] Semi-automated dishwashing systems, in which the dishes are
returned via a conveyor system which has, for example, a feed
conveyor belt or the like for feeding washware to the conveyor
dishwasher, are increasingly being used in relatively large
catering establishments in particular. The conveyor system may be
in the form, for example, of a tray-return belt onto which trays
with dishes or the dishes can be directly placed at a
dish-receiving point and from there fed to the conveyor dishwasher
either directly or via a manual pre-clearing station or pre-sorting
station. It goes without saying that other solutions are also
feasible for the conveyor system.
[0004] Conveyor dishwashers (conveyor warewashers) are used in the
commercial field. In contrast to domestic dishwashers, in which the
washware to be cleaned remains stationary in the machine during
cleaning, in the case of conveyor dishwashers, the washware is
transported through various treatment zones of the machine. In the
case of conveyor dishwashers, the washware is conveyed through a
plurality of treatment zones, for example a pre-wash zone or zones,
a main-wash zone or zones, a post-wash or pre-rinse zone or zones,
a final-rinse zone or zones and a drying zone or zones. A
transportation apparatus which generally has compartments for
accommodating washware is used to transport the washware through
the conveyor dishwasher in a transportation direction. In the case
of a flight-type dishwasher, the compartments may be formed by
supporting fingers on a transportation belt of the transportation
apparatus. In rack-conveyor dishwashers, dish racks in which
compartments can be formed for accommodating the washware to be
treated serve as the transportation apparatus. It is feasible here
for the dish racks to be transported through the rack-conveyor
dishwasher by a conveyor device.
[0005] DE 196 08 030 C1 describes a system for washing washware
having a conveyor dishwasher in which the process parameters of the
individual treatment zones (pre-wash zone, main-wash zones and
possibly final-rinse zone) can be matched to the respective
washware during operation, so that the washware can be cleaned in
an effective and economical manner. In the case of this
conventional conveyor dishwasher, a total of two different types of
washware are taken into consideration, specifically "drinking
glasses, plates, trays" on the one hand and "pots and pans,
containers, tubs" on the other hand. Furthermore, the degree of
soiling of the washware to be treated plays a role when selecting
the process parameters.
[0006] DE 10 2005 021 101 A1 discloses a system for washing
washware having a conveyor dishwasher in which the final-rinse zone
has two spray arms which are separate from one another. At least
one of the two spray arms is switched on or switched off as
required. The additional spray arm in the final-rinse zone is
switched on or switched off either as a function of the
transportation speed or as a function of the type of washware, the
quantity of washware and the degree of soiling of the washware.
[0007] U.S. Pat. No. 6,530,996 B2 relates to a system for washing
washware having a conveyor dishwasher, in which a wash and/or
final-rinse program is automatically selected as a function of the
type of washware. In particular, the transportation speed and the
spray time are varied as a function of the type of washware.
[0008] The aim of the invention is to achieve the object of
developing a system for washing washware of the type mentioned in
the introduction such that--in comparison to the dishwashing
systems known from the prior art--the consumption of fresh water,
chemicals and energy can be further reduced during operation. A
further aim is to specify a method for operating a dishwashing
system of this type.
[0009] The number of units of washware which are fed to the at
least one conveyor dishwasher with the aid of the conveyor system
per unit time can be determined by virtue of the provision of a
washware detector apparatus which detects the presence of washware
in a prespecified or prespecifiable region of the conveyor system.
In this way, the operating load on the dishwashing system can be
detected and the expected degree of utilization of the conveyor
dishwasher or dishwashers can be predicted. This permits the
operating parameters of the conveyor dishwasher or dishwashers to
be matched to the amount of washware in good time, since it is
already known in advance how many units of washware will soon have
to be treated in the at least one conveyor dishwasher.
[0010] The dishwashing system according to the invention
accordingly also has a control device which automatically selects a
predefined or predefinable (e.g, set or stored in memory of the
control device by being preset during machine manufacture and/or
subject to on-site adjustment by a service person or machine
operator according to the particular needs of the machine
installation) treatment program and sets the process parameters
associated with the selected treatment program as a function of the
detected number of units of washware which are fed to the at least
one conveyor dishwasher with the aid of the conveyor system per
unit time for the at least one conveyor dishwasher. Since the
number of units of washware which are fed to the conveyor
dishwasher per unit time is determined by the washware detector
apparatus which detects the presence of washware in a prespecified
or prespecifiable region of the conveyor system, the expected
degree of utilization of the conveyor dishwasher is already known
in advance. A certain lead time is accordingly provided with
respect to setting process parameters in the conveyor dishwasher,
this lead time possibly being necessary to change or adapt certain
process parameters.
[0011] This is particularly true when, for example, the quantity of
wash liquid sprayed in the at least one wash zone of the conveyor
dishwasher per unit time and/or the quantity of final-rinse liquid
sprayed in the at least one final-rinse zone per unit time is to be
matched to the degree of utilization of the conveyor dishwasher.
Under certain circumstances, these process parameters can be
changed only with a time delay, since a certain lead term is
required so that the spray jets fan out properly in the at least
one wash zone or in the at least one final-rinse zone and therefore
effective treatment of the washware in the wash zone or in the
final-rinse zone can be guaranteed.
[0012] Since a predefined or predefinable program sequence is
automatically selected and the process parameters associated with
the selected program sequence are set for the conveyor dishwasher
as a function of the expected degree of utilization of the conveyor
dishwasher by means of the solution according to the invention, it
is ensured that the control device can always select and set the
optimum operating parameters for treating the washware. The
"optimum process parameters" are to be understood to be process
parameters with which the washware is treated not only in an
effective manner but also in a particularly economical manner in
the individual treatment zones of the conveyor dishwasher.
[0013] In a preferred embodiment of the solution according to the
invention, at least one of the process parameters listed below is
automatically set or changed as a function of the detected number
of units of washware which are fed to the conveyor dishwasher per
unit time: [0014] the transportation speed at which the washware is
transported through the individual treatment zones of the conveyor
dishwasher; [0015] a quantity of wash liquid sprayed in the at
least one wash zone of the conveyor dishwasher per unit time;
[0016] a quantity of final-rinse liquid sprayed in the at least one
final-rinse zone of the conveyor dishwasher per unit time; [0017] a
temperature value of an air stream used to dry the washware in a
drying zone of the conveyor dishwasher; and/or [0018] a volumetric
quantity of a drying-air stream circulating in a drying zone of the
conveyor dishwasher for drying the washware per unit time.
[0019] In addition or as an alternative to this, it is further
preferred when, in this embodiment of the dishwashing system
according to the invention, at least one conveyor dishwasher is
provided which has a first main-wash zone, with main-wash nozzles,
and a second main-wash zone, likewise with main-wash nozzles, which
is connected downstream of the first main-wash zone, with the
control device being designed to automatically switch on or switch
off either the supply of wash liquid to the main-wash nozzles of
the first main-wash zone or the supply of wash liquid to the
main-wash nozzles of the second main-wash zone (switch-on and
switch-off of wash zones) as a function of the detected number of
units of washware which are fed to the at least one conveyor
dishwasher per unit time.
[0020] Since not only the quantity of wash liquid which is sprayed
per unit time or the quantity of final-rinse liquid which is
sprayed per unit time, but additionally also the transportation
speed, are changed, this can have the effect that the contact time
of the washware in the respective treatment zones of the conveyor
dishwasher is no longer than would actually be necessary for
adequate treatment. Overtreatment of the washware is therefore
prevented.
[0021] In the dishwashing system according to the invention, in
principle only as many resources of water, energy and chemicals are
accordingly consumed in the respective treatment zones of the
conveyor dishwasher as are actually necessary to ensure adequate
processing (cleaning, final-rinsing, drying). In particular, the
consumption of fresh water, which is sprayed onto the washware in
the final-rinse zone of the conveyor dishwasher in pure form or
with further additives added, can be markedly reduced during
operation of the dishwashing system.
[0022] In one possible embodiment of the dishwashing system
according to the invention, it is feasible for the process
parameters of a first treatment program, for example the process
parameters for partial-load operation, to be automatically set up
to a predefined or predefinable number of units of washware which
are fed with the aid of the conveyor system per unit time in the
conveyor dishwasher, and for the process parameters of a second
treatment program, for example the process parameters for full-load
operation, to be automatically set when the predefined or
predefinable number of units of washware which are fed with the aid
of the conveyor system per unit time in the conveyor dishwasher is
exceeded. In this preferred embodiment too, the settable process
parameters preferably include at least one of the following
parameters: the transportation speed at which the washware is
transported through the individual treatment zones of the conveyor
dishwasher; the quantity of wash liquid sprayed in the at least one
wash zone per unit time; and/or the quantity of final-rinse liquid
sprayed in the at least one final-rinse zone per unit time.
[0023] It is therefore feasible, in particular, for the
transportation speed during partial-load operation, that is to say
when the process parameters of the first treatment program are set,
to be reduced compared to full-load operation, while at the same
time both the quantity of wash liquid which is sprayed in the at
least one wash zone of the conveyor dishwasher per unit time and
the quantity of final-rinse liquid which is sprayed in the at least
one final-rinse zone of the conveyor dishwasher per unit time are
likewise reduced compared to full-load operation.
[0024] The method according to the invention is a solution for
operating a system for washing washware which has at least one
conveyor dishwasher and a conveyor system for feeding washware to
the at least one conveyor dishwasher. The method according to the
invention can be used to reduce the consumption, in particular, of
fresh water during operation of a dishwashing system of this type
in a manner which is particularly easy to implement but is
nevertheless effective.
[0025] The invention will be described below on the basis of a
preferred embodiment as an example and with reference to the
drawings, in which:
[0026] FIG. 1 schematically shows a plan view of a system for
washing washware according to the invention; and
[0027] FIG. 2 schematically shows a longitudinal sectional view
through a conveyor dishwasher which is used in the system according
to FIG. 1.
[0028] FIG. 1 schematically shows a plan view of an embodiment of
the dishwashing system 100 according to the invention. This is
accordingly a semi-automated dishwashing system which has a first
conveyor dishwasher 2 for washing dishes, glasses and pots and
pans, and also a second conveyor dishwasher 2' for washing trays
and items of cutlery. A conveyor system 101 is also provided. The
conveyor system 101 extends from a washware-receiving region 103 to
the second conveyor dishwasher 2' and serves to convey washware
from the washware-receiving region 103 to the inlet region 11' of
the second conveyor dishwasher 2'.
[0029] The washware is preferably fed to the conveyor dishwasher 2'
at a constant rate of advance. Furthermore, the abovementioned
first conveyor dishwasher 2 is provided in the outlet region of the
conveyor system 101. In the illustrated embodiment, this first
conveyor dishwasher 2 serves to wash dishes, for example plates,
cups, saucers, bowls and containers and vessels. The design and the
manner of operation of the second conveyor dishwasher 2' which is
used in the dishwashing system 100 according to FIG. 1 will be
described below with reference to the illustration in FIG. 2. The
first conveyor dishwasher 2, which serves to wash dishes, glasses
and pots and pans, is, in principle, of identical design to the
second conveyor dishwasher 2', but with not only one main-wash zone
14', but two main-wash zones 14a, 14b which are arranged one behind
the other, being provided here. A single main-wash zone 14' is
sufficient in the second conveyor dishwasher 2' since the types of
washware to be treated in the second conveyor dishwasher 2' are
generally not heavily soiled and therefore a plurality of main-wash
zones are not needed.
[0030] Identically acting components are denoted by the same
reference numerals in the first conveyor dishwasher 2 and the
second conveyor dishwasher 2', with the reference numerals
associated with the treatment zones of the second conveyor
dishwasher 2' being provided with an apostrophe in order to draw a
distinction. The manner of operation of the second conveyor
dishwasher 2' will be described below with reference to the
illustration according to FIG. 2. These explanations apply in an
equivalent sense to the manner of operation of the first conveyor
dishwasher 2 too.
[0031] The washware which is transported to the two conveyor
dishwashers 2, 2' with the aid of the conveyor system 101 is
pre-sorted with respect to the type of washware in a pre-sorting
region 104. In detail, provision is made here for the washware
which is to be treated in the first conveyor dishwasher 2 (glasses
and dishes) to be moved manually from the conveyor system 101 onto
the transportation apparatus 4 of the first conveyor dishwasher 2
in the pre-sorting region 104. This ensures that only trays and
cutlery are fed to the second conveyor dishwasher 2' with the aid
of the conveyor system 101.
[0032] The dishwashing system 100 according to the present
invention is distinguished in that a washware detector apparatus 51
is provided which is designed to detect the presence of washware in
a prespecified or prespecifiable region of the conveyor system 101.
In the preferred embodiment according to FIG. 1, the conveyor
system 101 is designed such that the washware is fed to the two
conveyor dishwashers 2, 2' at a predefined or predefinable feed
rate. In this way, the washware detector apparatus 51 is also
suitable for detecting the number of units of washware which are
fed to the conveyor dishwashers 2, 2' with the aid of the conveyor
dishwasher 101 per unit time.
[0033] The washware detector apparatus 51 preferably has at least
one optically, inductively or capacitively operating detector
device 51' which is designed to detect the presence of washware in
the prespecified or prespecifiable region of the conveyor system
101. It is particularly advantageous when the detector device 51'
is designed to detect the presence of individual trays, individual
dishes, individual pots and pans, individual glasses, individual
items of cutlery and/or individual containers.
[0034] In the dishwashing system 100 illustrated in FIG. 1, a
control device 50 is also provided, which is designed to
automatically select a predefined or predefinable treatment program
and set the process parameters associated with the selected
treatment program for at least one of the two conveyor dishwashers
2, 2' as a function of the detected number of items of washware fed
to the two conveyor dishwashers 2, 2' per unit time.
[0035] It is preferred here when the control apparatus 50 is
designed to set the process parameters, which are associated with
the selected treatment program, with a time delay in the at least
one conveyor dishwasher 2, 2', with the time delay depending on the
distance of the region of the conveyor system 101 monitored by the
detector device 51' from the at least one conveyor dishwasher 2, 2'
and on the feed rate at which the washware is fed to the at least
one conveyor dishwasher 2, 2'.
[0036] The exact manner of operation of the control device 50 is to
be described in conjunction with the conveyor dishwasher 2' which
is schematically illustrated in FIG. 2.
[0037] FIG. 2 schematically shows a longitudinal sectional view
through the second conveyor dishwasher 2' which is used to wash
trays and cutlery in the dishwashing system according to FIG. 1.
The conveyor dishwasher 2' is equipped with a transportation
apparatus 4' for transporting washware (not illustrated) through
the conveyor dishwasher 2' in a transportation direction 8. The
conveyor dishwasher 2' has at least one wash zone, for example as
illustrated in FIG. 2, a pre-wash zone 12' and a main-wash zone 14'
which is arranged downstream of the pre-wash zone 12' as seen in
the transportation direction 8.
[0038] A post-wash zone 16' is arranged downstream of the at least
one wash zone 12', 14' as seen in the transportation direction 8,
and at least one final-rinse zone, for example only a single
final-rinse zone 18' as illustrated, is arranged downstream of the
post-wash zone 16'. In the conveyor dishwasher 2' illustrated in
FIG. 2, a drying zone 40' follows the final-rinse zone 18' in the
transportation direction 8 of the washware. The respective zones
12', 14', 16', 18', 40' of the conveyor dishwasher 2' can be
separated from one another by means of separating curtains 47. In
the embodiment illustrated in FIG. 2, the inlet tunnel 10' itself
is also separated from the inlet 11' by means of a separating
curtain 47. Wash liquid and final-rinse liquid are prevented from
splashing over and vapours are prevented from escaping from the
conveyor dishwasher 2' by virtue of the provision of the separating
curtains 47.
[0039] Spray nozzles 20, 22, 24, 26, 28, 30 are associated with the
said treatment zones 12', 14', 16', 18' of the conveyor dishwasher
2'. These spray nozzles 20, 22, 24, 26, 28, 30 serve to spray
liquid onto the washware when the said washware is transported
through the respective treatment zones 12', 14', 16', 18' by the
transportation apparatus 4'. The individual spray systems of the
treatment zones 12', 14', 16', 18' ensure that the washware to be
treated is sprayed both from above and from below.
[0040] However, in the conveyor dishwasher 2' which is
schematically illustrated in FIG. 2, the final-rinse zone 18' not
only has downwardly directed upper spray nozzles 20 and upwardly
directed lower spray nozzles 22, but also transversely directed
lateral spray nozzles 24 on each side of the transportation
apparatus 4'. The use of lateral spray nozzles 24 permits targeted
spraying of areas of the washware with a final-rinse liquid in
shadow zones too. The use of lateral spray nozzles 24 in the
final-rinse zone 18' has a clear advantage in terms of the
final-rinse result (effective rinsing of detergent residues from
surfaces of the washware in shadow zones too) over systems in which
only upper and lower spray nozzles 20, 22, and no transversely
directed lateral spray nozzles 24, are provided in the final-rinse
zone 18', specifically when the transportation system is fully
loaded, that is to say, for example, when the tray carrier is
loaded with one tray next to another.
[0041] The post-wash zone 16', main-wash zone 14' and pre-wash zone
12' also have associated tanks (post-wash tank 32, main-wash tank
34, pre-wash tank 36) for accommodating sprayed liquid and/or for
providing liquid for the spray nozzles 26, 28, 30 of the relevant
treatment zones 14', 16', 18'.
[0042] As already mentioned, the first conveyor dishwasher 2, in
the dishwashing system 100 illustrated in FIG. 1, likewise has a
transportation apparatus 4 for transporting washware (not
illustrated) through the conveyor dishwasher 2 in the
transportation direction 8. The first conveyor dishwasher 2 also
has a pre-wash zone 12 and a (first) main-wash zone 14a, which is
arranged downstream of the pre-wash zone 12 as seen in the
transportation direction 8, downstream of an inlet tunnel 10 as
seen in the transportation direction 8. In contrast to the second
conveyor dishwasher 2' according to FIG. 2, a further (second)
main-wash zone 14b is provided downstream of the (first) main-wash
zone 14a as seen in the transportation direction 8 in the first
conveyor dishwasher 2. A post-wash zone 16 is arranged downstream
of the second main-wash zone 14b as seen in the transportation
direction 8, and at least one final-rinse zone, for example only a
single final-rinse zone 18 as illustrated, is arranged downstream
of the post-wash zone 16. In the first conveyor dishwasher 2 which
is illustrated in plan view only in FIG. 1, a drying zone 40
follows the final-rinse zone 18 in the transportation direction 8
of the washware.
[0043] The treatment zones 10, 12, 14a, 14b, 16 and 18 of the first
conveyor dishwasher 2 are identical to the corresponding treatment
zones 10', 12', 14', 16' and 18' in terms of function and
structure, and so the treatment zones 10, 12, 14a, 14b, 16 and 18
of the first conveyor dishwasher 2 are not described in detail.
[0044] As already indicated, final-rinse liquid, which comprises
fresh water together with rinse aid which is added in a metered
manner, is sprayed onto the washware (not illustrated) via the
spray nozzles 20, 22, 24 of the final-rinse zone 18', which spray
zones are arranged above and below the transportation apparatus 4'
and also laterally, in the second conveyor dishwasher 2'
illustrated in FIG. 2. Some of the sprayed final-rinse liquid is
transported from treatment zone to treatment zone, counter to the
transportation direction 8 of the washware, by means of a cascade
system. The remainder of the final-rinse liquid which is sprayed in
the final-rinse zone 18' is conducted directly into the pre-wash
tank 36 which is associated with the pre-washed zone 12' via a
valve V1 and a bypass line 38.
[0045] In the cascade system, the final-rinse liquid which is
sprayed by the final-rinse nozzles 20, 22, 24 flows from the
final-rinse zone 18' into the post-wash tank 32, which is
associated with the post-wash zone 16', due to the force of
gravity. The final-rinse liquid which is sprayed in the final-rinse
zone 18' and collected by the post-wash tank 32 is then conveyed to
the spray nozzles (post-wash nozzles 26) of the post-wash zone 16'
with the aid of a post-wash pump 45.
[0046] Wash liquid is rinsed off from the washware in the post-wash
zone 16'. The liquid produced in the process (post-wash liquid)
flows into the main-wash tank 34, which is associated with the
main-wash zone 14', due to the force of gravity. An outflow element
39, for example an outflow base or a baffle plate which conducts
the post-wash liquid, which is sprayed by the post-wash nozzles 26,
into the main-wash tank 34, is preferably provided for this
purpose. According to another embodiment (not shown), the outflow
element 39 can be dispensed with when the main-wash tank 34 extends
as far as beneath the post-wash nozzles 26 of the post-wash zone
16'.
[0047] The liquid accommodated by the main-wash tank 34 of the
main-wash zone 14' is usually provided with a detergent and is
sprayed onto the washware via the spray nozzles (main-wash nozzles
28) of the main-wash zone 14' with the aid of a main-wash pump 35.
The wash liquid sprayed by the main-wash nozzles 28 flows back into
the main-wash tank 34 due to the force of gravity.
[0048] The main-wash tank 34 forms a fluid connection with the
pre-wash tank 36, which is associated with the pre-wash zone 12',
via an overflow line 37. The wash liquid which is sprayed in the
main-wash zone 14' enters the pre-wash tank 36 via this overflow
line 37 when a sufficient quantity of wash liquid is accommodated
in the main-wash tank 34.
[0049] The liquid accommodated in the pre-wash tank 36 of the
pre-wash zone 12' is then sprayed onto the washware via the spray
nozzles (pre-wash nozzles 30) of the pre-wash zone 12' with the aid
of a pre-wash pump 33, in order to remove coarse particles of dirt
from the washware. The wash liquid which is sprayed by the pre-wash
nozzles 30 flows back into the pre-wash tank 36 due to the force of
gravity.
[0050] The pre-wash tank 36 is provided with an overflow line 31
which serves to feed the excess quantity of liquid to a wastewater
system when a liquid level in the pre-wash tank 36 is exceeded.
[0051] As already indicated, the liquid which is sprayed in the
main-wash zone 14' and in the pre-wash zone 12' preferably contains
detergent which is added in a metered manner, for example, to the
liquid which is accommodated in the main-wash tank 34 of the
main-wash zone 14' with the aid of a detergent-metering apparatus
(not shown in the drawings).
[0052] As already mentioned, the drying zone 40' follows the
final-rinse zone 18' in the transportation direction 8. The
washware is dried with dry and heated air in the drying zone 40',
in order to blow off or dry off the moisture on the washware. In
order to keep the moisture content of the air in a range which is
favourable for drying purposes, it is feasible, for example, to
feed ambient air from the outside to the drying zone 40' via an
opening, for example through the outlet opening for the
washware.
[0053] The warm and moist air in the drying zone 40' is then drawn
out of the drying zone 40' via a further opening with the aid of a
fan 41, for example. In this case, it is advantageous when the
discharge-air stream out of the drying zone 40' passes a
heat-recovery device 42 in which a condenser may be provided, for
example. The heat-recovery device 42 serves to recover at least
some of the thermal energy contained in the discharge air.
[0054] The first conveyor dishwasher 2 has a drying zone 40 which
corresponds to the drying zone 40'.
[0055] If the tanks (pre-wash tank 36, main-wash tank 34, post-wash
tank 32) which are associated with the wash zones 12', 14' and 16'
are empty or only inadequately filled before the conveyor
dishwasher 2' is first started, the said tanks first have to be
filled via a fresh-water line 90 and/or by spraying final-rinse
liquid into the final-rinse zone 18'. The fresh-water line 90 can
be connected to a fresh-water supply system via a controllable
valve V3. The quantity of wash liquid available in the main-wash
zone 14' and in the pre-wash zone 12' can in each case be monitored
with the aid of a level sensor which is provided in the main-wash
tank 34 and respectively with the aid of a level sensor which is
provided in the pre-wash tank 36, and reported to a control
apparatus 50.
[0056] The final-rinse zone 18' can--as illustrated in FIG. 2--have
an associated fresh-water container 30 for buffer-storing at least
some of the fresh water provided for final rinsing. The fresh-water
container 30 is provided at one end with a fresh-water connection,
which can be connected to a fresh-water supply system via a
controllable fresh-water feed valve V2, and at the other end to the
intake side of a final-rinse pump 43. However, it goes without
saying that it is also feasible to dispense with a fresh-water
container 30 for buffer-storing at least some of the fresh water
provided for final rinsing, and to connect the fresh-water feed
valve V2 directly to the intake side of the final-rinse pump
43.
[0057] The pressure side of the final-rinse pump 43 is connected to
a water heater 9 (boiler) via a line system. In this case, the line
system is designed in such a way that the liquid conveyed to the
spray nozzles 20, 22, 24 of the final-rinse zone 18' by the
final-rinse pump 43 passes the heat-recovery device 42 before it
reaches the water heater 9. In this way, it is possible to make use
of at least some of the thermal energy of the discharged discharge
air to heat the liquid fed to the spray nozzles 20, 22, 24 of the
final-rinse zone 18'.
[0058] Rinse aid is added in a metered manner to the fresh water,
which is fed to the final-rinse pump 43 either directly by the
fresh-water feed valve V2 or by the fresh-water container 30, with
the aid of a rinse aid-metering apparatus (not explicitly
illustrated in FIG. 2).
[0059] The control device 50, which has already been described in
conjunction with the dishwashing system 100 illustrated in FIG. 1,
is schematically illustrated in the second conveyor dishwasher 2'
illustrated in FIG. 2. The control device 50 is designed to
automatically set specific process parameters as a function of the
number of units of washware which are fed to the conveyor
dishwashers 2, 2' with the aid of the conveyor system 101 per unit
time, the said number of units of washware being detected with the
aid of the washware detector apparatus 51. The control device 50 is
preferably designed to control the different controllable
components of the conveyor dishwashers 2, 2', for example the
respective pumps and valves, in accordance with a predefined or
predefinable program sequence, in order to thus be able to set the
process parameters in the individual treatment zones 12, 14a, 14b,
16, 18 or 12', 14', 16', 18' of the conveyor dishwasher 2 or 2' and
also the transportation speed of the transportation apparatus 4 or
4'.
[0060] The control device 50 is preferably designed to
automatically set the transportation speed, at which the washware
is transported through the individual treatment zones 12, 14a, 14b,
16, 18 or 12', 14', 16', 18' of the conveyor dishwasher 2 or 2', to
a predefined or predefinable value as a function of the detected
number of units of washware which are fed to the conveyor
dishwashers 2, 2' per unit time; and/or to automatically set a
quantity of wash liquid sprayed in the at least one wash zone 12,
14a, 14b or 12', 14' per unit time to a predefined or predefinable
value as a function of the detected number of units of washware
which are fed to the conveyor dishwashers 2, 2' per unit time;
and/or to automatically set a quantity of final-rinse liquid
sprayed in the final-rinse zone 18 or 18' of the conveyor
dishwasher(s) 2 or 2' per unit time to a predefined or predefinable
value as a function of the detected number of units of washware
which are fed to the conveyor dishwashers 2, 2' per unit time.
[0061] As an alternative or in addition to this, it is preferred
when the control device 50 is designed to automatically select a
predefined or predefinable program sequence in the drying zone 40,
40' of at least one of the conveyor dishwashers 2, 2' and set the
process parameters associated with the selected program sequence as
a function of the detected number of units of washware which are
fed to the conveyor dishwashers 2, 2' per unit time. It is feasible
here, in particular, for the control device 50 to be designed to
automatically select a predefined or predefinable temperature value
of an air stream used in the drying zone 40, 40' of at least one of
the conveyor dishwashers 2, 2' to dry the washware and set the
temperature of the air stream used for drying purposes to the
selected value as a function of the detected number of units of
washware which are fed to the conveyor dishwashers 2, 2' per unit
time.
[0062] As an alternative or in addition to this, it is also
feasible for the control device 50 to be designed to automatically
select a predefined or predefinable value of a volumetric quantity
of a drying-air stream circulating in the drying zone 40, 40' of at
least one of the conveyor dishwashers 2, 2' for drying the washware
per unit time and set the volumetric quantity circulating per unit
time to the selected value as a function of the detected number of
units of washware which are fed to the conveyor dishwashers 2, 2'
per unit time.
[0063] In the conveyor dishwasher (second conveyor dishwasher 2')
illustrated in FIG. 2, it is feasible, in particular, for the
control device 50 to be designed to automatically switch on or
switch off the supply of wash liquid to the pre-wash nozzles 30 of
the pre-wash zone 12 or 12' as a function of the detected number of
units of washware which are fed to the conveyor dishwashers 2, 2'
per unit time; and/or to automatically switch on or switch off the
supply of wash liquid to the main-wash nozzles 28 of the main-wash
zone(s) 14a, 14b or 14' as a function of the detected number of
units of washware which are fed to the conveyor dishwashers 2, 2'
per unit time.
[0064] The control apparatus 50 is connected to the washware
detector apparatus 51 via a suitable communications connection in
order to check the type of washware which is fed to the conveyor
dishwasher 2 and detected by the washware detector apparatus 51
continuously or at prespecified times or events.
[0065] The dishwashing system 100 according to the invention is
therefore also suitable for carrying out a method for washing
washware, with the following method steps being executed: [0066] a)
the number of units of washware which are fed to the conveyor
dishwasher(s) 2, 2' with the aid of the conveyor system 101 per
unit time is detected with the aid of the washware detector
apparatus 51 in the prespecified or prespecifiable region of the
conveyor system 101; and [0067] b) a predefined or predefinable
treatment program is automatically selected and the process
parameters associated with the selected treatment program are set
in the conveyor dishwasher 2, 2' as a function of the detected
number of units of washware which are fed to the conveyor
dishwasher(s) 2, 2' per unit time.
[0068] The process parameters of a first treatment program are
preferably automatically set here up to a predefined or
predefinable number of units of washware which are fed with the aid
of the conveyor system 101 per unit time in the conveyor dishwasher
2 or 2', with the process parameters of a second treatment program
being automatically set when the predefined or predefinable number
of units of washware which are fed with the aid of the conveyor
system 101 per unit time in the conveyor dishwasher 2 or 2' is
exceeded. The settable process parameters include at least one of
the following parameters: the transportation speed at which the
washware is transported through the individual treatment zones 12,
14a, 14b, 16, 18 or 12', 14', 16', 18' of the conveyor dishwasher 2
or 2'; the quantity of wash liquid sprayed in the at least one wash
zone 12, 14a, 14b or 12', 14' per unit time; the quantity of
final-rinse liquid sprayed in the at least one final-rinse zone 18
or 18' per unit time; the temperature value of an air stream used
to dry the washware in the drying zone 40 or 40'; and/or the
volumetric quantity of a drying-air stream circulating in the
drying zone 40, 40' for drying the washware per unit time.
[0069] In a preferred further development of the method according
to the invention, the transportation speed at which the washware is
transported through the individual treatment zones 12, 14a, 14b,
16, 18 or 12', 14', 16', 18' of the conveyor dishwasher 2 or 2',
the quantity of wash liquid sprayed in the at least one wash zone
12, 14a, 14b or 12', 14' per unit time, and the quantity of
final-rinse liquid sprayed in the at least one final-rinse zone 18
or 18' per unit time are in each case automatically increased when
a predefined or predefinable number of units of washware which are
fed with the aid of the conveyor system 101 per unit time is
exceeded in the conveyor dishwasher 2 or 2'.
[0070] In particular, it is feasible for the temperature of the
drying-air stream to be set to an average value of, for example, 55
to 65.degree. C. at an average transportation speed in the drying
zone 40, 40' of the at least one conveyor dishwasher 2, 2', and/or
for the volumetric quantity of drying air circulating per unit time
to be set to an average value of, for example, 1500 to 2500
m.sup.3/h.
[0071] The invention is not restricted to the embodiments of FIG. 1
and FIG. 2 shown by way of example in the drawings. Rather, the
invention can be gathered from an overall expert view of the patent
claims and of the description of the exemplary embodiment.
[0072] It is therefore feasible, for example, for only one of the
two conveyor dishwashers 2, 2' to be controlled with the aid of the
control device 50 as a function of the number of units of washware
which are fed by the conveyor system 101 per unit time.
[0073] It is also feasible for the control device 50 to be designed
to selectively automatically select a predefined or predefinable
treatment program for at least one conveyor dishwasher 2, 2' and
set the process parameters associated with the selected treatment
program in the at least one conveyor dishwasher 2, 2' as a function
of the detected number of units of washware which are fed per unit
time.
[0074] With regard to the first conveyor dishwasher 2 which has the
first main-wash zone 14a, with main-wash nozzles 28, and the second
main-wash zone 14b, likewise with main-wash nozzles 28, which is
connected downstream of the first main-wash zone 14a, it is finally
also feasible for the control device 50 to be designed to
automatically switch on or switch off either the supply of wash
liquid to the main-wash nozzles 28 of the first main-wash zone 14a
or the supply of wash liquid to the main-wash nozzles 28 of the
second main-wash zone 14b as a function of the detected number of
units of washware which are fed to the at least one conveyor
dishwasher 2 per unit time (e.g., the control device may be set so
that wash liquid supply to only one of the main wash zones 14a and
14b is switched on or off and the other is not).
* * * * *