WO2012122984A1

WO2012122984A1 - An assembly and a method of producing hot water for industrial cleaning

Info

Publication number: WO2012122984A1
Application number: PCT/DK2012/000021
Authority: WO
Inventors: Hans JØRGENSEN
Original assignee: DTV MACHINERY APS
Current assignee: DTV MACHINERY APS
Priority date: 2011-03-16
Filing date: 2012-03-13
Publication date: 2012-09-20
Anticipated expiration: 2013-09-16

Abstract

An assembly (1) for producing hot water with a preselected working temperature for the cleaning of production equipment and areas in the food and processing industries, containing a three-way valve (2) with inlet openings (3, 4) for cold and hot water supply (A, B), an outlet opening (5) for the water with the selected working temperature. The three-way valve (2) is driven by an electric motor (6) in a closed regulation system with a control panel (7), an electronic PID regulator (9) and a thermosensor (13). The thermosensor is arranged after the outlet (5) of the three-way valve. The PID regulator transmits control signals to the electric motor of the three-way valve for changing the position of the motor valve in response to the difference between the signal from the output of the control panel and the signal from the output of the thermosensor.

Description

An assembly and a method of producing hot water for industrial cleaning

The invention relates to an assembly for producing hot water with a prese- lected working temperature for the cleaning of production equipment and areas in the food and processing industries, said assembly containing a three-way valve with inlet openings, to which a cold water supply and a hot water supply are connected, as well as an outlet opening, from which water with the selected working temperature is discharged.

The invention moreover relates to a method of producing hot water with a preselected working temperature as well as use of the assembly for industrial cleaning. The document US 2002/0134847 A1 describes a water mixer with a cold water supply and a hot water supply and an outlet with a temperature sensor. The valves of the two water supplies are driven by their respective motors arranged in a control panel, in which also a CPU is arranged, which controls the supply of cold and hot water. The water mixer shown appears as an expensive product with valves, gears and motors for individual control of both water supplies and with a control panel which allows setting of washing function, temperature and pressure. Typically, the water mixer is intended for a kitchen, and, in the embodiment shown, it will hardly be able to operate for an extended period of time in an industrial environment.

Today, heavy demands are made on the cleaning of both production plants and production areas within the food and processing industries. At the end of the working day and when switching between productions, plant and area must be cleaned to a standard which has been laid down by the vet- erinary and environmental authorities. The cleaning is performed manually by flushing, washing and rinsing plant and area with hot water to which a cleaning agent has been added. Generally, the cleaning equipment comprises a T-shaped branch pipe equipped with ball cocks on each branch. Hot and cold water are connected to two of the branches, following which the ball cocks are set until water with a suitable temperature and pressure is produced on the third branch. This setting is performed manually by the cleaning staff.

The water is passed on to a pumping station and a soap adding device and from there further on via a hose of a length of ten to thirty metres to the cleaning position. Frequently, the hose is provided with a ball cock on its outlet.

However, there are various demands on the temperature of the water de- pending on which food or processing industry is involved, as the properties for fat and protein vary from animal species to animal species.

The fishing industries operate with cleaning temperatures from 25 to 45 degrees Celsius, with the high temperatures being used after the process- ing of fat fish.

Slaughterhouses operate with cleaning temperatures from 25 to 60 degrees Celsius, with the high temperatures being used after slaughtering and processing of livestock and poultry.

Dairies operate with cleaning temperatures from 45 to 60 degrees Celsius, with the high temperatures being used after cheese production.

The processing industries operate with temperatures from 25 to 60 degrees Celsius. There is a tendency among the cleaning staff to use only hot water or at least too hot water, because the setting of the ball cocks on the branch pipe is too difficult. As a consequence, the company has an unnecessarily great consumption of hot water and thus added costs on the consumption and heating of the water.

Moreover, when using too hot water, it often happens that protein substances stick to the surface of the plant, so that it is necessary to add liquid containing chlorine or acid to the washing water in order to be able to re- move the protein substances. In other words, it is important that the working temperature of the water can be set correctly, so that the optimum washing effect is achieved, where fat and the protein substances are removed without any risk of the protein substances getting stuck. The object of the invention

It is the object of the invention to provide an assembly and to teach a method which remedy the above-mentioned drawbacks, which are capable of achieving and maintaining a preselected temperature, which are easy to operate, and which are sturdy and operationally reliable.

Summary of the invention

The object stated above is achieved, as stated in claim 1 , by an assembly for producing hot water with a preselected working temperature for the cleaning of production equipment and areas in the food and processing industries. The assembly comprises a three-way valve with inlet openings, to which a cold water supply and a hot water supply are connected, as well as an outlet opening, from which water with the selected working temperature is discharged. The three-way valve is driven by an electric motor and forms part of a closed regulation system, which additionally comprises a control panel with an electrical signal output for temperature setting, an electronic PID regulator with at least two electrical signal inputs and an electrical signal output, as well as a thermosensor with a signal output, wherein the thermosensor is arranged after the outlet of the three-way valve, and the PID regulator is connected to the electric motor of the three-way valve and transmits control signals for changing the position of motor valve in response to the difference between the signal from the output of the control panel and the signal from the output of the thermosensor. This assembly makes it possible to produce a working temperature of the water which, within the normal pressures and temperatures for supplies of cold and hot water, will be capable of maintaining the preselected working temperature, also even if the pressures and the temperatures of the supplies should vary.

Moreover, the working temperature is produced automatically and therefore is not dependent on wrong settings, if any, of ball cocks and the operator's own ideas on what is best. At a correct working temperature, a saving of the water consumption and of the heating of the water is achieved, and sticking of proteins is also avoided, which results in a saving of chemicals.

As stated in the characterizing portion of claim 2, the control panel is equipped with a switch for the selection of working setting and a contact for the selection of working temperature, and its signal output is connected electrically to the positive signal input of the PID regulator.

This ensures that the operation and the setting of the equipment are un- complicated and just consist in activating the switch which serves to select working setting, as well as the contact which serves to select the desired temperature. The number of selectable temperatures is determined on the basis of the need for cleaning in the production area concerned. It is moreover ensured that the selected temperature is included as a controlling input signal in the closed regulation system.

When, as stated in claim 3, the thermosensor is resistance-based, and its signal output is connected electrically to the negative signal input of the PID regulator, an electrical signal will be sent back to the regulator which shows a snap shot of the working temperature of the water.

When, as stated in claim 4, the thermosensor is arranged in the immediate vicinity of the outlet of the three-way valve, a rapid indication of temperature changes will be provided to the PID regulator. Furthermore, it is expedient, as stated in claim 5, to construct the assembly to have a capacity of up to 12 m³/h, so that large production areas may be cleaned within a reasonable time.

It is additionally expedient, as stated in claim 6, to adapt the assembly to work within the temperature range of 25 degrees Celsius to 60 degrees Celsius.

With a method as stated in claim 7 it is ensured that water with a selected temperature for industrial cleaning may be produced in a simple manner.

Moreover, it is expedient, as stated in claim 8, to use the assembly for cleaning in the food and processing industries.

The drawing

Exemplary embodiments of the invention will be explained more fully below with the reference to the drawing, in which: fig. 1 shows a basic sketch of the assembly for producing hot water fig. 2 shows a basic sketch of a complete cleaning system of which the assembly of fig. 1 forms part, fig. 3 shows details of a wiring diagram of the control system for the assembly, and fig. 4 shows details of the wiring diagram and the control panel.

Detailed description of the invention An assembly 1 for producing hot water with a preselected working temperature for industrial cleaning is shown in fig. 1.

The assembly 1 comprises a three-way valve 2 with an inlet 3 for hot water and an inlet 4 for cold water as well as an outlet 5, from which water with a mixed temperature flows out. The inlet 3 is connected with a hot water supply (not shown) via the feed line A, and the inlet 4 is connected with a cold water supply (not shown) via a feed line B. The outlet 5 is connected with a thermosensor 13, which is mounted in a pipe section C, which conveys water with the desired working temperature further on to a pumping station.

The mix ratio of cold water to hot water is determined by the position of the three-way valve in the valve housing. The valve 2 is equipped with an electric motor 6, which changes the position of the valve via the shaft 6a until the mix ratio corresponds to the selected working temperature.

The electric motor 6 is of the type which may be controlled via electrical signals from a regulation unit. Advantageously, the motor type may be of the make Belimo and may have a response time of 10 angular degrees per second or more. The motor 6 is controlled by a regulation unit comprising a PID regulator 9, which is set to regulate the water temperature as rapidly as possible to the desired value. The regulator 9 may be programmed to regulate on the basis of entered selectable setpoints, each of which represents a specific water temperature.

The selectable setpoints or temperatures are provided as a pushbutton 7a on the control panel 7, and repeated activation of this contact produces the selected temperature signal on the display 23 and on the output 8 of the control panel. The output 8 is connected to the positive input 10 of the PID regulator 9.

A switch 7b is also provided, which is capable of switching the assembly to work in a manual position where only cold water is metered, and to work in an automatic setting where the assembly meters water with the selected temperature.

The pipe section C has mounted thereon a resistance-based thermosensor 13, which continuously measures the temperature of the water flowing through the pipe section. Most advantageously, the thermosensor 13 is mounted in direct extension of the outlet 5 of the three-way valve 2, but it may also be mounted on the pipe section C at a distance from the valve, in the event that special mounting conditions in the production area should call for this. An electrical signal representing the temperature in the pipe section C is passed from the signal output 14 of the thermosensor back to the negative input 1 1 of the PID regulator.

This allows the regulator 9 to compare the signals on the inputs 10 and 11 , and, if they differ, to transmit a control signal via the output 12 to the motor 6, which changes the position of the three-way valve in a direction which reduces and eliminates the difference.

Both the control panel 7 and the regulator 9 may advantageously be incorporated in water-tight box containing the control system shown in fig. 3 and fig. 4, so that it is protected against water, and against the situation that the operating staff changes the internal settings of the regulator. In that case, the box is provided with a window so that the display 23 is visible.

Fig. 2 shows the assembly 1 coupled to a pumping station.

The hot water is conveyed via the pipe C further on to a flow switch 15, a water clock 16 and a non-return valve 17 and from there further on through a pump 18 to a section 21 for the addition of chemicals and/or washing agents and further on to a cleaning hose with a stop cock 22. The stop cock is operated by the person who cleans the area, and it is desirable that the water is turned off when there is a cessation in the cleaning task, e.g. in connection with the pulling of the hose to a new position.

The pump 18 is equipped with a control unit 19, which is adapted to receive a signal from a control panel 20 and from a flow switch 15. The control unit applies a signal to the pump which corresponds to the incoming signals. The performance of the pump is set on the control panel 20. The flow switch 15 signals whether water is consumed. If water is not consumed, the pump is stopped.

The water clock 16 measures the consumption of water, and the non-return valve 17 prevents backflow of water. The section 21 for the addition of washing chemicals may be constructed in different ways. The section may be equipped with pumps or with an injector system for metering the washing chemicals.

Fig. 3 and fig. 4 show the control system, and how the PID regulator 9 is connected to the electric motor 6 of the valve, to the control panel 7 and to the thermosensor 3. The pushbuttons 24 shown on the regulator are concealed behind the control panel of the control box and may only be oper- ated by an electrician. The display 23 is visible through a window.

With the assembly 1 , a method of producing hot water with a selected water temperature for cleaning may be carried out by conveying cold and hot water to the assembly, which then regulates the mix ratio of hot water to cold water until the water temperature at the outlet of the assembly corresponds to the selected temperature.

When using the assembly 1 for cleaning in the food and processing industries, the user will know with considerable certainty that the cleaning satis- fies the sanitary requirements.

Claims

PATENT CLAIMS

1. An assembly (1 ) for producing hot water with a preselected working temperature for the cleaning of production equipment and areas in the food and processing industries, said assembly containing a three-way valve (2) with inlet openings (3, 4), to which a cold water supply (A) and a hot water supply (B) are connected, as well as an outlet opening (5), from which water with the selected working temperature is discharged via the outlet connection (C), characterized in that the three-way valve (2) is driven by an electric motor (6) and forms part of a closed regulation system, which additionally comprises a control panel (7) with an electrical signal output (8), an electronic PID regulator (9) with at least two electrical signal inputs (10, 11 ) and an electrical signal output (12) as well as a thermosensor (13) with an electrical signal output (14), wherein the thermosensor is arranged after the outlet (5) of the three-way valve, and the output of the PID regulator is connected to the electric motor of the three-way valve and transmits control signals for changing the position of the motor valve in response to the difference between the signal from the output of the control panel and the signal from the output of the thermosensor.

2. An assembly according to claim 1 , characterized in that the control panel (7) is equipped with a switch (7b) for the selection of working setting and with a contact (7a) for the selection of up to five different temperatures, and that its signal output (8) is connected electrically to the positive signal input (10) of the PID regulator.

3. An assembly according to claims 1 - 2, characterized in that the thermosensor (13) is resistance-based, and that its signal output (14) is connected electrically to the negative signal input (1 1 ) of the PID regulator.

4. An assembly according to claims 1 - 3, characterized in that the ther- mosensor (13) is arranged directly after the outlet (5) of the three-way valve.

5. An assembly according to claims 1 - 4, characterized in that the water supplies (A) and (B), the three-way valve (2) and the outlet connection (C) have a capacity of up to 12 m³/h.

6. An assembly according to claims 1 - 5, characterized in that the working temperatures are set via the control panel (7) and are in the range from 25 degrees Celsius to 60 degrees Celsius.

7. A method of producing hot water with a selected temperature for cleaning in the food and processing industries with an assembly according to claims 1 - 6, characterized in that the temperature of the water is estab- lished by supplying cold water (A) and hot water (B), respectively, to the inlet openings (3, 4) of the assembly (1 ), which regulate the quantitative ratio of cold to hot water until the temperature of the water at the outlet (C) of the assembly corresponds to the selected temperature.

8. Use of the assembly according to claims 1 - 6 for producing hot water with a selected working temperature for cleaning in the food and processing industries.