JP2008237953A - Method and device for removing dirt of stainless steel-made components - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for removing the dirt of stainless steel-made components without using detergents or chemicals, and also provide a device which executes the method. <P>SOLUTION: In the method for removing the dirt of stainless steel-made components, stainless steel-made components to be washed are heated at 1,000-1,300°C in an evacuated heating room to remove the dirt of the stainless steel-made components. The dirt-removing device for executing the dirt-removing method is provided with; a heating room 51; a basket 52 for holding the stainless steel-made components to be washed which are arranged in the heating room; a heater 53 for heating the heating room; a sucking pump 54 for evacuating the inside of the heating room; a hydrogen gas source 55 for introducing hydrogen gas into the heating room; and a nitrogen gas source 56 for introducing nitrogen gas into the heating room. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to the cleaning of stainless steel parts, and more particularly to a method for removing dirt from stainless steel parts for storing or handling liquid or solid contents such as food and drink, and a dirt removing apparatus for carrying out the method. .

    Stainless steel has excellent workability and is used in a variety of fields that are resistant to rusting, but it is often used especially in containers and equipment that handle household items and food and drinks that require good hygiene. Yes. For example, as a device having a complicated stainless steel pipe through which a fluid flows, there is a beverage cooling supply device that cools and dispenses a beverage. There is a beer server as an example of a typical example of this beverage supply and cooling device. This beer server is installed in restaurants, restaurants, beer halls, etc., and is a device for pouring and providing beer according to customers' requests. is there.

  FIG. 1 shows a schematic diagram of a beer server and its usage. The beer server 1 includes a water tank 10, a cooling device 11 for cooling water in the water tank, and a stainless steel cooling coil 21 accommodated in the water tank 10. The One end of the cooling coil is connected to a beer hose 24 connected to the beer barrel 3 via a head 23, and the other end is connected to a currant 22 having a pouring cock for pouring beer. The beer barrel 3 is pressurized through the gas hose 41 to the carbon dioxide gas cylinder 4, and the beer in the beer barrel 3 is supplied to the beer server by the gas pressure. The beer server shown here has a structure in which the passage portion of beer including the cooling coil can be easily separated as indicated by an arrow. By adopting such a structure, in particular, a cooling coil portion that needs to be cleaned relatively frequently can be taken out and cleaned.

  Since this beer server is a device for handling beer, which is a beverage, it must naturally be placed under strict hygiene management. However, as the number of days of use increases, the remaining beer liquid adheres and becomes soiled with organic substances. And accumulate. Therefore, this beer server needs to be regularly cleaned in order to maintain good hygiene. The beer server usually has a structure that passes through a passage through the cooling tank to cool the beer that is a beverage, and this cooling passage is usually coiled and has a complicated structure. This makes cleaning difficult.

  Further, not only beer servers but also containers, parts, or pipes made of stainless steel are conventionally washed with chemicals and detergents to remove dirt adhered to the surface, and then the chemicals are removed. A method of rinsing with water is used. Moreover, since the thing with long shapes, such as piping, may remain | survive in the inside, pneumatic pressure is sent into the inside of piping.

  For example, several proposals have been made so far for a method for cleaning the inside of the cooling passage of the beer server. For example, tap water is used to supply detergent together with water in the cooling coil (Patent Document 1), or cleaning liquid is supplied to the cooling passage of a beer server using the pressure of carbon dioxide (patent) Document 2) exists.

  However, when chemicals and detergents are used, a subsequent water rinsing process is necessary, and complicated shapes such as containers and piping cannot be easily removed by simply immersing them in chemicals. There is a problem that the time is long.

In addition to the above method, a method of removing dirt using ultrasonic waves is known as a cleaning method for containers and pipes having complicated shapes. In this method, even if the part has a complicated shape, such as a pipe, the chemical and the contaminated part that have entered the pipe by ultrasonic vibration can be brought into contact with each other by vibration to remove the dirt. Since ultrasonic cleaning is performed by putting parts in the water tank, multiple parts can be cleaned at the same time.However, after cleaning, it is necessary to rinse the chemicals and remove residual water. There are problems such as lengthening.
JP 62-125299 A Japanese Patent Laid-Open No. 11-171298

  The present invention has been made to solve the above-described problems, and by treating a plurality of the same stainless steel products and parts at a time, the cleaning processing time can be shortened, and the chemicals Has been made for the purpose of providing a method and apparatus for removing stains on stainless steel products that do not require cleaning water removal.

  The above-mentioned problem is that a stainless steel part to be cleaned is removed by heating the stainless steel part to be cleaned in a vacuum oven in the range of 1000 ° C. to 1300 ° C. It is solved by the dirt removal method.

In addition, a dirt removing apparatus for carrying out the dirt removing method of the present invention,
A heating chamber, a cage for holding a target stainless steel part disposed in the heating chamber, a heater for heating the heating chamber, a suction pump for evacuating the heating chamber, and the heating chamber A hydrogen gas source for introducing hydrogen gas, and a nitrogen gas source for introducing nitrogen gas into the heating chamber.

  The term “stainless steel parts” used in the present invention is used to include “parts” as a part of a product and “stainless steel products” that are a single product.

  The method of removing dirt according to the present invention is particularly effective when applied to a coiled conduit for passing through a cooling tank as a stainless steel part to cool a beverage having a complicated shape.

  The dirt removal method according to the present invention merely heats a target part made of stainless steel in a vacuum, and can process a large number of parts at the same time as compared with cleaning using a conventional detergent or chemical. In addition to saving labor, it is possible to remove dirt even with complicated and complicated parts and products. In addition, it is not necessary to perform treatment such as acid cleaning, and not only can the background become satin but also the gloss of the parts can be recovered. Moreover, since it processes at high temperature, sterilization can also be performed simultaneously.

  Hereinafter, embodiments of the present invention will be described.

  The method for removing dirt from a stainless steel part according to the present invention is performed by heating the stainless steel part in a temperature range of about 1000 ° C. to 1300 ° C. not exceeding the melting point of stainless steel of 1500 ° C. And this heating is performed in a vacuum. As a result, organic contaminants adhering to the stainless steel part are removed by burning. The reason why the heating is performed in vacuum is to avoid this because if the organic substance is heated in the presence of oxygen, it remains in the state of being fixed on the stainless steel surface as an oxide scale when it burns. Since the method according to the present invention merely heats a stainless steel part in a vacuum, even if the part has an intricate shape or complicated structure, all parts are heated, resulting in a shape or structure. Can remove dirt regardless of.

  FIG. 2 shows a schematic configuration of a dirt removing apparatus 5 for carrying out a dirt removing method for removing dirt from a stainless steel product or a stainless steel part according to the present invention. The dirt removing device 5 includes a heating chamber 51, a basket 52 for holding the stainless steel part 6 which is a component to be purified, which is disposed in the heating chamber 51, a heater 53 for heating the heating chamber 51, and the heating chamber 51. Are provided with a suction pump 54 for evacuating, a hydrogen gas source 55 for introducing hydrogen gas into the heating chamber 51, and a nitrogen gas source 56 for introducing nitrogen gas into the heating chamber 51.

  Next, the procedure of the method for removing dirt from stainless steel parts using the dirt removing apparatus will be described.

  (1) First, a stainless steel part, which is a target product for which dirt is to be removed, is placed in the basket 52 in the heating chamber 51.

  Prior to introducing the stainless steel part into the heating chamber 51, it is preferable to dry the stainless steel part to evaporate and remove the adhering moisture and oil. If moisture or oil is attached, they will evaporate and cause a decrease in vacuum.

  (2) Next, with the inside of the heating chamber 51 sealed, the vacuum pump 54 is driven to bring the inside of the heating chamber 51 into a vacuum state. The vacuum is for reducing oxygen and preventing oxidation during heating.

  (3) Hydrogen gas is introduced. Here, the reason for introducing hydrogen gas is that it is difficult to make a complete vacuum, and a trace amount of oxygen remains. Therefore, hydrogen gas is introduced, hydrogen substitution is performed, oxygen is reduced to the limit, and reduction is performed. This is to create an atmosphere.

  (4) Vacuuming is again performed with a vacuum pump (up to a vacuum degree of about 13 Pa).

  (5) The heater is heated in the range of 1000 ° C. to 1300 ° C. below the melting point of the stainless part. For example, it is heated at 1080 ° C. for about 40 minutes.

  (6) After heating, introduce nitrogen gas and cool.

  By performing the above treatment, the organic matter adhering to the stainless steel part is burned without being oxidized, so that no oxidized scale remains on the surface of the stainless steel part, and a process such as pickling is not necessary. .

  According to the method of the present invention, since the target stainless steel part is heated in a vacuum, no oxide film is formed on the stainless steel surface. In addition, when dirt such as an oxide film is present, it is necessary to perform pickling treatment. However, when pickling treatment is performed, the background becomes unsatisfactory, but heating according to the present invention is performed by pickling. Since the treatment is not performed, the surface is glossy. Therefore, it can also be called bright heat treatment.

  Next, as an example of the stainless steel product, an embodiment of the above-described method for removing dirt from the cooling coil of the beer server will be described.

  Below, the experiment example implemented in order to investigate the effect of the dirt removal method by this invention is shown.

(Experimental example 1)
First, an experiment was conducted using a stainless steel test piece to remove dirt using the dirt removal method of the present invention.

  FIG. 3A and FIG. 3B show the results of an experiment in which dirt was attached to a stainless steel specimen (FIG. 2A), and the degree of dirt removal (FIG. 2B) was examined by applying the dirt removing method of the present invention. It is. In this experiment, beer was boiled and concentrated as dirt, and applied to a stainless steel plate. FIG. 3A shows this state. FIG. 3B shows the result of carrying out this using the apparatus shown in FIG. 3 according to steps (1) to (6) of the soil removal method according to the present invention described above. FIG. 3B shows a state after the dirt removing method of the present invention is carried out, and shows that the applied dirt is completely burned and removed, although traces of dirt remain.

(Experimental example 2)
Next, an example in which the method for removing dirt according to the present invention is applied to the above-described beer server using the beer server and its accessories that are actually soiled by use will be described.

  FIG. 4 is an enlarged view showing a part of the cooling coil 21 of the beer server shown in FIG. Although the figure is outside the cooling coil 21, when used for a long period of time, in addition to organic substances, a patina derived from a copper cooling device in the water tank is attached to the surface.

  FIG. 5 is a photograph showing the state after the cooling coil 21 is applied with the dirt removal method by heating of the present invention. As can be seen from this figure, the outside of the cooling coil does not show adhering patina or dirt, and the gloss is restored.

  FIG. 6 is a photograph showing a state in which dirt attached to the inside of the stainless steel coil, which is a passage through which the beer of the cooling coil 21 passes, is removed. In the pipe shown in the upper part of the figure, there is dirt with dirt attached inside the pipe. This stain is a residue of the remaining beer as organic matter. The photograph showing the inside of the pipe shown below shows the state after applying the dirt removing method according to the present invention. As described above, even if dirt adheres to the inside of the coil-shaped complicated passage, the dirt can be removed by applying the dirt removal method by heating according to the present invention without using high-pressure water pressure. I understand that I can do it.

  Furthermore, since the method according to the present invention is performed in a vacuum, no oxide film is generated by heating.

(Experimental example 3)
7A and 7B show a state in which the method for removing dirt according to the present invention is performed on a stainless steel beer barrel 3 used in association with the beer server shown in FIG. FIG. 6A shows the upper surface of the beer barrel 3 and is written with the words “for testing” and “technical center” using a partially broken label and a test oil-based ink. FIG. 7B shows a state after applying the dirt removing method of the present invention. It can be seen that the letters and labels made with oil-based ink are completely burned out and the stain is removed. The beer barrel usually gets dirty on the inner and outer surfaces when used for a long time. Conventionally, cleaning has been performed by using a chemical and rubbing with a brush or the like, which has been troublesome. According to the method of the present invention, such work is not required, and the dirt can be removed by a simple method.

  As mentioned above, although the experiment example was described taking the beer server which is a drink cooling supply apparatus as an example in connection with embodiment of this invention, this invention is clearly applicable not only to a drink cooling supply apparatus but to all stainless steel products. It is. Here, some points to be noted in applying the present invention to a stainless steel part or product will be described.

  The dirt removing method according to the present invention includes a process of heating a target stainless steel product to a high temperature (1000 ° C. to 1300 ° C.) within a range of a melting point (about 1500 ° C.) or less. Therefore, even when a part or product to which the method of the present invention is applied is heated to this temperature range, a change occurs so that its physical and chemical properties affect the subsequent use of the part. It is necessary not to. Stainless steel is broadly divided into Cr-based alloys containing Cr as the main alloy element and Cr-Ni-based materials containing Cr and Ni. Furthermore, the Cr system is divided into martensite and ferrite based on the structure produced, and the Cr-Ni system is largely classified into the austenite system. A typical ferrite type is SUS 430, and a typical austenite type is SUS304. When the soil removal method of the present invention is applied to these different types of stainless steel, there is no particular problem with the austenite type represented by SUS304, but with the ferritic SUS430, it turns out to be slightly black. Therefore, it is necessary to grasp the optimum temperature condition.

It is a figure which shows the schematic block diagram of a beer server. It is a figure which shows schematic structure of the dirt removal apparatus which concerns on embodiment of this invention. It is a figure which shows the state which adhered dirt on the test piece. It is a figure which shows the state after applying the dirt removal method of this invention. It is a figure which shows a part of cooling coil to which the dirt of the beer server adhered. It is a figure which shows the cooling coil after dirt removal. It is a figure which shows the state inside the channel | path of the cooling coil of a beer server. It is a figure which shows the upper surface of the beer barrel to which dirt adhered. It is a figure which shows the upper surface of the beer barrel from which dirt was removed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Beer server 10 Cooling tank 11 Cooling device 21 Cooling coil 22 Curran 23 Head 3 Beer barrel 4 Carbon dioxide gas cylinder 5 Dirt removal device 51 Heating chamber 52 Basket 53 Heating heater 54 Suction pump 55 Hydrogen gas source 56 Nitrogen gas source

Claims (5)

A method for removing stains on a stainless steel part, wherein the stainless steel part to be cleaned is heated in a range of 1000 ° C. to 1300 ° C. in a vacuumed heating chamber to remove the dirt adhered to the stainless steel part. Introducing a stainless steel part to be cleaned into the heating chamber;
Vacuuming the heating chamber;
Introducing hydrogen gas into the heating chamber;
Replacing hydrogen gas in the heating chamber with nitrogen gas;
Sucking the hydrogen gas from the heating chamber to form a vacuum;
Heating the heating chamber;
A step of cooling by introducing nitrogen gas into the heating chamber after the heating is completed;
A method for removing dirt from a stainless steel part, which removes dirt adhering to a stainless steel part comprising: The dirt removing method according to claim 1 or 2, wherein the stainless steel part is a coiled conduit for passing through the cooling tank in order to cool the beverage. Stainless steel having a heating chamber, a cage for holding a target stainless steel part disposed in the heating chamber, a suction pump for evacuating the heating chamber, and a heater for heating the heating chamber A dirt remover that removes dirt from parts. The dirt removing apparatus according to claim 3, further comprising: a hydrogen gas source for introducing hydrogen gas into the heating chamber; and a nitrogen gas source for introducing nitrogen gas into the heating chamber.