JPH11384A - Sterlizing method of powder and grain - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve sanitary performance, and also preclude the possibility of nonuniformity of sterilization and contamination by inputting powder and grain to a vertical type inverse conical vessel, and pushing up the powder and grain along a vessel peripheral wall part by a spiral ribbon blade. SOLUTION: First of all, steam is introduced to a jacket 6, and a vessel is heated, and powder and grain F to be sterilized is inputted to the vessel, and a temperature is raised up to a prescribed temperature. The powder and grain F is efficiently heated since it is carried upward along a vessel peripheral wall being a heating surface by a spiral ribbon blade 4. When an article temperature of the powder and grain F reaches the prescribed temperature, superheated steam is blown into from a vessel bottom part, and after air in the vessel is substituted with the superheated steam, a valve 8 is closed, and the superheated steam is blown into further, and it is sterilized. When sterilization finishes, the steam in the vessel is exhausted, and a drying hot blast is blown into from the vessel bottom part, and it is dried. After drying finishes, chilled water is supplied to the jacket 6, and the inside of the vessel is ventilated and cooled, and after being cooled up to the prescribed temperature, it is discharged from the vessel bottom part, and becomes a product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for disinfecting a granular material such as a pharmaceutical or a food material, and more particularly to a method for disinfecting a granular material using superheated steam.

[0002]

2. Description of the Related Art Conventionally, the following methods have been employed for sterilizing powders such as pharmaceuticals and food materials. Heat sterilization while floating and transporting the granular material in the pipeline with low pressure superheated steam,
What is called an air-flow sterilization method (Japanese Patent Application Laid-Open No. 56-2618)
No. 0), a high-speed stirring type sterilization method, in which a stirring blade is rotated at high speed in a horizontal cylindrical pressure vessel to form an annular layer of granular material in the vessel and heat sterilized with superheated steam or the like. (Eg, Japanese Patent Application Laid-Open No. 57-82686), and a so-called drop-type sterilization method (eg, Japanese Patent Application Laid-Open No. 59-140841) in which a granular material is heated and sterilized while being dropped in superheated steam under pressure.

[0003] The air-stream sterilization method has a problem in that it is difficult to disassemble the apparatus and thus has a problem in cleaning properties. Further, there are disadvantages in that ancillary equipment such as a steam circulating blower and a cyclone increases and equipment and running costs become expensive. In the high-speed stirring type sterilization method, since there is a shaft seal portion of the stirring shaft before and after the horizontal cylindrical container, it is exposed to the granular material during operation, and there is a problem of sanitary property. In addition, there is a problem in the mixing property in the front-rear direction, so that sterilization unevenness may occur. In the drop-type sterilization method, some materials are not uniformly exposed to superheated steam, and sterilization unevenness is likely to occur.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for sterilizing powders and granules which is excellent in sanitary properties and which is free from non-uniform sterilization or contamination with a simple apparatus.

[0005]

According to a first aspect of the present invention, a heating means is provided on a peripheral wall, and the inside of a container is provided with a heating means.
A rotating shaft is suspended from the upper lid of the container, and a spiral ribbon wing whose blade is wider toward the upper part of the container is attached to this.A vertical inverted conical container with a guide plate suspended from the upper lid of the spiral ribbon wing is attached to the upper part of the spiral ribbon wing. The powder and granules are charged, and the powder and granules are pushed up along the peripheral wall of the container by the spiral ribbon blade, and are stirred and mixed so as to be guided from the peripheral wall to the center by the guide plate. The method is characterized in that the granules are heated and sterilized by introducing superheated steam from the lower part of the container.

[0006] Since the powdery material charged into the vertical inverted conical container is carried from the container peripheral wall to the upper part by the ribbon wings whose blades become wider toward the upper part of the container, the powder is efficiently heated from the peripheral wall. . Further, since the guide plate guides the container to the center portion, it is possible to prevent a so-called vortex state in which the peripheral wall portion of the container rises and the center portion is depressed, so that uniform mixing becomes possible. In such a state, the superheated steam is blown from the lower part of the container, so that the superheated steam can be sufficiently brought into contact with the powder and granules, thereby enabling efficient sterilization.

The means for solving the problem described in claim 2 is characterized in that, in addition to the requirements described in claim 1, after the introduction of the superheated steam, the stirring and mixing state is maintained for a certain period of time. As a result, the granular material can be brought into sufficient contact with the superheated steam, so that the granular material can be more reliably sterilized.

The means for solving the problem described in claim 3 is characterized in that, after sterilization, the inside of the container is dried and cooled by reducing the pressure after sterilization. As a result, since drying and cooling after sterilization are performed promptly, quality is not impaired.

[0009]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a schematic diagram of an apparatus for implementing the present invention. Reference numeral 1 denotes a container main body having an inverted conical portion below some cylindrical portion, and reference numeral 2 denotes a container upper lid, which is heated to prevent dew condensation.
Reference numeral 3 denotes a rotating shaft suspended from the upper lid coaxially with the center of the container. Since the rotating shaft is suspended from the upper lid, no bearing is required at the lower end. Reference numeral 4 denotes a spiral ribbon blade attached to the rotation shaft. In the spiral ribbon blade, the width of the blade increases toward the top along the inner wall of the container. Reference numeral 5 denotes a guide plate fixed to the upper lid, and guides the powdered material carried to the upper portion of the container peripheral wall by the spiral ribbon blade to the center of the container. Reference numeral 6 denotes a container peripheral wall heating means, which has a jacket structure here, but may be a pipe wound around the container outer periphery or a heating wire. Reference numeral 7 denotes a vacuum pump. Code 8
Denotes an exhaust valve provided on the container upper lid 2.

Next, a sterilization method using the present apparatus will be described.
The motor M is started to rotate the rotating shaft 3 and the jacket 6 is rotated.
Steam is introduced into the vessel and the vessel is heated. Next, the powdery granules F to be sterilized are charged into a container and heated to a predetermined temperature. The granular material F charged into the container is conveyed upward along the container peripheral wall, which is a heating surface, by the spiral ribbon blade, and thus is efficiently heated. Since the width of the spiral ribbon blade 4 is larger at the upper part, mixing properties in the radial direction are good, and further, at the upper part of the spiral ribbon blade 4, a guide plate 5 for guiding the pushed-up powder to the center of the container is provided. Therefore, the surface of the granular material is
Since the particles are almost flat without exhibiting a vortex shape, even particles having different particle diameters can be uniformly mixed without segregation. ADVANTAGE OF THE INVENTION According to this invention, since the mixing property of a granular material is very good, it heats uniformly in a short time. When the product temperature of the granular material reaches a predetermined temperature, superheated steam is blown from the bottom of the container, the air in the container is replaced with the superheated steam, the valve 8 is closed, and the superheated steam is further blown and pressurized to the sterilization temperature. Raise the temperature and sterilize.

After the temperature of the granules reaches the sterilization temperature in accordance with the type of the granules, the introduction of the superheated steam is stopped, and the inside of the container body 1 is closed to remove the granules. If this state is maintained for a certain period of time while stirring and mixing, the powder and granules sufficiently contact the superheated steam, so that sterilization can be performed more reliably. At this time, in order to avoid a temperature rise above the sterilization temperature of the powder and granules, an operation such as lowering the heating temperature of the jacket 6 or opening the valve 8 to lower the pressure in the container body 1 may be performed.

When the sterilization is completed, the valve 8 is opened to evacuate the steam in the container to break the pressure, and hot air for drying is blown from the bottom of the container to dry. After drying is completed, cold water is supplied to the jacket 6 and cooled by ventilating the inside of the container. After cooling to a predetermined temperature, the product is discharged from the bottom of the container to be a product. In addition, if this drying and cooling step is performed under vacuum by operating a vacuum pump while supplying cold water to the jacket instead of steam, the powder and particles rising along the container peripheral wall can be cooled from the container peripheral wall. It is cooled quickly by self-evaporation under reduced pressure. Therefore, since drying and cooling can be performed in a short time, quality is not impaired.

In the apparatus used in the present invention, the rotating shaft, spiral ribbon wing, and guide plate attached to the inside of the container can all be removed from the inside of the container by pulling up the upper cover of the container. Excellent sanitary properties. In addition, since the rotating shaft is suspended from the container top lid and has a cantilever structure having no bearing at the lower end, there is no danger of contamination between the powder and particles in the container and the bearing portion. .

[0014]

Next, an example of sterilizing cut dried seaweed according to the present invention will be described. The dried dried seaweed cut into the container body 1 was put therein, mixed with stirring, heated from the jacket and the product temperature became 80 ° C, and superheated steam was introduced from the bottom of the container and the product temperature became 100 ° C. The supply of the superheated steam was stopped, and the mixture was dried and cooled and taken out. The number of viable bacteria before sterilization is 37,000 / g, and that after sterilization is 140 / g.
Became. When the product was returned to hot water after sterilization, good quality evaluation was obtained without browning or slimming.

Next, an example of sterilizing granular black pepper before crushing will be described. The granular black pepper is put into the container main body 1, mixed with stirring, heated from the jacket, and the product temperature becomes 8%.
When the temperature reached 0 ° C., superheated steam was introduced from the bottom of the vessel, the valve 8 was closed, the supply of the superheated steam was continued, and the temperature was increased. When the product temperature reached 112 ° C., the supply of the superheated steam was stopped. After maintaining this state for 5 minutes, it was dried and cooled under reduced pressure and taken out. The number of viable bacteria before sterilization is 5 × 10 ⁶ / g
And good results of 0 / g were obtained.

[0016]

According to the present invention, a granular material is charged into a vertical inverted conical container, and the granular material is pushed up along the peripheral wall of the container by a spiral ribbon blade whose blades are wider toward the upper part of the container. Since the powder and granules are stirred and mixed by the guide plate so as to be guided to the center of the container, the mixing properties of the powder and granules are extremely excellent. Therefore, heating from the container peripheral wall and contact with superheated steam are also excellent, so that sterilization can be performed efficiently.
Furthermore, sterilization can be performed more reliably by continuing the stirring and mixing state for a certain period of time after the superheated steam is blown, and since the product is dried and cooled under vacuum after sterilization, it can be cooled quickly and does not impair the quality of the product. Further, since the spiral ribbon blade and the guide plate in the container can be pulled out and there is no bearing at a portion in contact with the granular material, the sanitary property is excellent and there is no risk of contamination.

[Brief description of the drawings]

FIG. 1 is a schematic view of the movement of a granular material according to the present invention and the apparatus used.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container main body 2 Container top lid 3 Rotation axis 4 Spiral ribbon wing 5 Guide plate 6 Jacket 7 Vacuum pump 8 Valve F Powder and granular material M Motor

Claims (3)

[Claims] 1. A heating means is provided on a peripheral wall, and inside the container,
A rotating shaft is suspended from the upper lid of the container, and a spiral ribbon wing whose blade is wider toward the upper part of the container is attached to this.A vertical inverted conical container with a guide plate suspended from the upper lid of the spiral ribbon wing is attached to the upper part of the spiral ribbon wing. The powder and granules are charged, and the powder and granules are pushed up along the peripheral wall of the container by the spiral ribbon blade, and are stirred and mixed so as to be guided from the peripheral wall to the center by the guide plate. A method for sterilizing powders and granules, comprising heating the granules and introducing superheated steam from the lower part of the container to sterilize the granules. 2. The method according to claim 1, wherein the stirring and mixing state is maintained for a predetermined time after the superheated steam is introduced. 3. The method for sterilizing powders and granules according to claim 1, wherein the inside of the container is dried and cooled by reducing the pressure after sterilization.