Heating or sterilization treatment device of granular materials

Abstract

To provide a heating or sterilization treatment device of granular materials which is high in hardness, hardly causes abrasion while preventing the adhesion of the granular materials, and comprises a heating part which is strong against thermal deformation.SOLUTION: A heating or sterilization treatment device of granular materials comprises: supply means 11 of granular materials 10; a granular material input part 12 into which the granular materials 10 are inputted; a condensable gas supply part 13; a heating part 14 which heats the granular materials 10; and a decompression part 15 which releases a mixed body of the granular materials 10 and the condensable gas supply part into a space having a pressure lower than that of the heating part 14. The heating part 14 is formed of metal, and is applied with a plating layer on an inner face. At a surface of the plating layer, a contact angle with water is equal to or larger than 90°, a surface roughness is equal to or lower than Ra 1.6 μm, and a hardness is equal to or higher than HV 140. When the granular materials 10 are inputted into the condensable gas, in the mixed body in the heating part 14, the heat of the condensable gas is transmitted to the granular materials 10 while circulating, coagulation occurs on surfaces of the granular materials 10, and the granular materials 10 are released into a space having a pressure lower than that of the heating part 14 through the decompression part 15, and are heated or sterilized.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a heating or sterilizing treatment device for powder or grain using a condensable gas, and more particularly to a heating or sterilizing treatment device for powder or grain that can prevent adhesion and wear of powder or grain to the inner surface of a heating part. [Background technology]

[0002] Conventionally, there is known a heat treatment apparatus in which powder or grain is introduced into a current of a condensable gas and heated to sterilize it (for example, see Patent Document 1 below). In such a heat treatment apparatus, the powder or grain flows through a heating section together with the condensable gas. In the heating section, the powder or grain is heated by the condensable gas, and condensation occurs on the surface of the powder or grain due to the temperature difference between the condensable gas and the powder or grain. If there is a lot of this condensation, the powder or grain is likely to adhere to the inner surface of the heating section. This is particularly true for ingredients with high sugar or oil content (such as chili peppers) and ingredients that absorb water and become sticky (such as thickeners).

[0003] When powder or granular material adheres to the inner surface of the heating section, the powder or granular material adheres to itself and forms clumps, or burns. If the clumps or burnt particles come off and enter the airflow, it can cause quality deterioration or foreign matter contamination. Furthermore, as adhesion to the inner surface of the heating section progresses, the surface area of ​​the heating section decreases, causing changes in the heat treatment conditions. If adhesion progresses further, the heating section becomes clogged, causing operation to be interrupted.

[0004] For this reason, devices that prevent the adhesion of powder or granular materials have been proposed. The following Patent Document 2 proposes a heat treatment device that prevents the adhesion of powder or granular materials by forming the inner surface of the heating part from a non-adhesive material. The same document also suggests that the non-adhesive material is preferably a fluororesin. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4499184 [Patent Document 2] Patent No. 6232242 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the non-adhesive material used in the heat treatment device described in Patent Document 2 is generally a resin, as typified by fluororesin, which has the problem of low hardness and easy wear. Such wear can cause foreign matter to be mixed in. Furthermore, as wear progresses, the surface area in the heating section increases, leading to a decrease in flow rate and internal pressure. In addition, as wear progresses, the life of the device becomes shorter. Furthermore, resin is easily thermally deformed, and it is necessary to keep the heating temperature in the heating section within a certain temperature range.

[0007] The present invention is devised to solve the above-mentioned problems of the conventional art, and has an object to provide a heating or sterilization treatment device for powder or granular material, which is provided with a heating section that is hard, resistant to wear, and resistant to thermal deformation while preventing adhesion of powder or granular material. [Means for solving the problem]

[0008] In order to achieve the above object, the heating or sterilization treatment device for powder or grain of the present invention comprises a supplying means for supplying powder or grain, a powder or grain input section into which the powder or grain is input from the supplying means, a condensable gas supplying section for blowing a condensable gas into the powder or grain, a heating section for heating the powder or grain with the condensable gas, and a pressure reducing section for releasing a mixture of the powder or grain and the condensable gas into a space having a lower pressure than the heating section, the heating section being made of metal, an inner surface of the heating section being provided with a plating layer, and a surface of the plating layer being in contact with water. The powder or grain has an antenna angle of 90 degrees or more, a surface roughness of Ra1.6 μm or less, and a hardness of HV140 or more. When the powder or grain is introduced into the condensable gas, the mixture flows under pressurized conditions at a flow rate of 200 m / sec or less in the heating section, and heat of the condensable gas is transferred to the powder or grain due to a temperature difference between the powder or grain and the condensable gas, causing condensation on the surface of the powder or grain, and the mixture is released through the decompression section to a space with a lower pressure than the heating section, where the powder or grain is heated or sterilized.

[0009] According to the heating or sterilization treatment device for powder or granular material of the present invention, the surface of the plating layer, which is the inner surface of the heating part, has a contact angle with water of 90 degrees or more and a surface roughness of Ra1.6 μm or less, thereby preventing adhesion of powder or granular material due to coagulation. In addition, the surface of the plating layer has a hardness of HV140 or more, which makes it hard to wear. This prevents the inclusion of foreign matter due to worn material, prevents the expansion of the surface area of ​​the inner surface due to wear, prevents a decrease in flow rate and internal pressure, and extends the life of the device. Furthermore, since the heating part has a configuration in which a plating layer is applied to the inner surface of a metal, it is resistant to thermal deformation, so the heating temperature can be increased. In addition to the simple structure, this configuration has high strength, so it is possible to reduce the weight by making the wall thinner.

[0010] The heating or sterilization treatment device for powder or grain of the present invention is preferably configured as follows: The inner surface of the pressure reducing section is provided with a plating layer, and the surface of the plating layer preferably has a contact angle with water of 90 degrees or more, a surface roughness of Ra1.6 μm or less, and a hardness of HV140 or more. With this configuration, the pressure reducing section can achieve the same effects as the heating section.

[0011] It is preferable that the pressure reducing portion is formed of a thin tube. With this configuration, the pressure reducing portion can be realized with a simple structure.

[0012] The pressure reducing section is preferably configured with a rotary valve. With this configuration, the time during which the powder or granular material is heated under pressurized conditions can be easily changed by changing the rotation speed of the rotary valve.

[0013] It is preferable that the heating part is grounded. This configuration can prevent the adhesion of powder and granular material to the inner surface of the heating part due to static electricity. This not only prevents quality deterioration and foreign matter contamination due to the generation of lumps and burnt parts, but also prevents the reduction of the surface area of ​​the inner surface of the heating part due to adhesion, prevents an increase in flow rate and internal pressure, and makes cleaning easier. Effect of the Invention

[0014] The effects of the present invention are as described above. According to the present invention, the surface of the plating layer, which is the inner surface of the heating part, has a contact angle with water of 90 degrees or more and a surface roughness of Ra1.6μm or less, so that adhesion of powder particles due to condensation can be prevented. In addition, the surface of the plating layer has a hardness of HV140 or more, so that it is hard and resistant to wear. This prevents the inclusion of foreign matter due to worn material, prevents the expansion of the surface area of ​​the inner surface due to wear, prevents a decrease in flow rate and internal pressure, and extends the life of the device. Furthermore, since the heating part is configured with a plating layer applied to the metal inner surface, it is resistant to thermal deformation, so the heating temperature can be increased. In addition to the simple structure, this configuration has high strength, so that it is possible to reduce the weight by making the wall thinner. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic diagram of a heating or sterilization treatment device according to one embodiment of the present invention. [Diagram 2] Cross-sectional view taken along line AA in FIG. [Diagram 3] FIG. [Figure 4] FIG. 2 is a side view showing a state in which the contact angle θ with water is greater than 90 degrees in one embodiment of the present invention. [Diagram 5] FIG. 4 is a schematic diagram of a heating or sterilization treatment device according to another embodiment of the present invention. [Figure 6] FIG. 4 is a cross-sectional view showing another embodiment (rotary valve) of the pressure reducing portion of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a schematic diagram of a heating or sterilization treatment apparatus 1 (hereinafter referred to as "apparatus 1") according to one embodiment of the present invention. The target of heating or sterilization treatment by the apparatus 1 is powdered or granular material 10. There is no particular limitation on the powdered or granular material 10, and examples thereof include grain flour such as wheat flour and rice flour, bran, seaweed flour, fish flour, vegetable flour, vegetable chip powder, tea leaf powder, spice powder such as pepper, powders of various additives, pharmaceutical powders, cosmetic powders, and powders of various feeds.

[0017] The present invention prevents the powdered or granular material 10 from adhering to the inner surface of the heating part 14, while making the heating part 14 hard, resistant to wear, and resistant to thermal deformation. Therefore, the effects of the present invention are particularly evident when heating powdered or granular material that is prone to adhesion, such as raw materials with high sugar or oil content such as chili peppers, or raw materials that absorb water and become sticky, such as thickeners. By undergoing a heating or sterilization process using the device 1, the proliferation of harmful organisms such as microorganisms and pests can be prevented in addition to the heating or sterilization treatment.

[0018] 1, the main components of the device 1 are a supply means 11, a powdered material input section 12, a condensable gas supply section 13, a heating section 14, and a pressure reduction section 15. In this embodiment, a hopper is used as the supply means 11, a screw feeder is used as the powdered material input section 12, a heating tube is used as the heating section 14, and a thin tube is used as the pressure reduction section 15. The condensable gas supply section 13 is composed of a condensable gas supply source 131 and a condensable gas supply path 132.

[0019] The powder / granular material input section 12 and the heating section 14 are connected via a raw material supply path 16. A cooling pipe 17 is connected to the downstream side of the pressure reducing section 15, and a cyclone 18 is connected to the downstream side of the cooling pipe 17. The cooling pipe 17 is connected to a blower 19 via an air blowing path 191.

[0020] Hereinafter, the heating or sterilization treatment of powdered or granular material 10 by the apparatus 1 will be described in the order of steps with reference to Fig. 1. In Fig. 1, powdered or granular material 10 is filled into supply means 11. The powdered or granular material 10 from supply means 11 is fed into powdered or granular material input section 12. The powdered or granular material 10 is transported within powdered or granular material input section 12 and fed to a raw material supply path 16. The powdered or granular material 10 that has passed through the raw material supply path 16 flows into a heating section 14.

[0021] At the inlet 141 of the heating section 14, a mixture of the condensable gas supplied from the condensable gas supply passage 132 and the powder or granular material 10 supplied from the raw material supply passage 16 is generated. The condensable gas is, for example, water vapor, and may be either saturated water vapor or superheated water vapor, or may be the vapor of various solvents. The mixture flows toward the pressure reducing section 15. In this embodiment, the heating section 14 is set so that the mixture flows at a flow rate of 200 m / sec or less under pressurized conditions.

[0022] In the heating section 14 and the decompression section 15, the powder or grain 10 is heated or sterilized by the condensable gas. Specifically, the heat of the condensable gas is transferred to the powder or grain due to the temperature difference between the powder or grain 10 and the condensable gas, causing condensation on the surface of the powder or grain, and the powder or grain 10 is released through the decompression section 15 into a space with a lower pressure than the heating section 14, whereby the powder or grain 10 is heated or sterilized.

[0023] The heated or sterilized powder or granule 10 is cooled in the cooling pipe 17. A non-condensable gas from the blower 19 is supplied into the cooling pipe 17 through the air passage 191. The non-condensable gas is, for example, air, oxygen, nitrogen, or carbon dioxide, and is a gas that does not condense even when cooled. In the cooling pipe 17, the mixed gas of the condensable gas and the powder or granule 10 is cooled by the non-condensable gas from the blower 19 and supplied to the cyclone 18. This allows the temperature of the powder or granule 10 to be lowered to a predetermined temperature before being supplied to the cyclone 18. The condensable gas and the powder or granule 10 are separated in the cyclone 18. The condensable gas is exhausted through the exhaust passage 181, and the powder or granule 10 separated from the condensable gas is collected through the collection passage 182.

[0024] The heating or sterilization treatment of powdered or granular material 10 by the device 1 has been described above, but in this embodiment, a configuration is adopted to prevent the powdered or granular material 10 from adhering to the inner surface of the heating unit 14, and this configuration will be described below. When the powdered or granular material 10 is put into the condensable gas in the heating unit 14, heat is transferred to the powdered or granular material 10 due to the temperature difference between the powdered or granular material 10 and the condensable gas, causing condensation on the surface of the granular material 10, and the powdered or granular material 10 is heated in a short time. On the other hand, condensation makes the powdered or granular material 10 more likely to adhere to the inner surface of the heating unit 14.

[0025] As already mentioned, when powder or granular material 10 adheres to the inner surface of heating unit 14, various problems arise, and therefore Patent Document 2 proposes preventing the adhesion of powder or granular material by forming the inner surface of heating unit 14 from a non-adhesive material. However, non-adhesive materials are generally resins, which have low hardness and are easily worn and thermally deformed, and therefore new problems arise, as already mentioned.

[0026] The inventors of the present application have devised a basic configuration in which a plating layer is applied to the inner surface of the metallic heating part 14, in order to achieve the object of realizing a heating part 14 that is hard, resistant to wear, and resistant to thermal deformation while preventing adhesion of powder or granular material 10. Fig. 2 shows a cross-sectional view of the heating part 14, which corresponds to the cross-sectional view taken along line AA in Fig. 1. The heating part 14 is formed by applying a plating layer 142 to the inner surface of a metal tube 141.

[0027] Furthermore, in order to more reliably achieve the above-mentioned objective, the inventors of the present application have devised a specific configuration in which the surface of the plating layer 142 has a contact angle with water of 90 degrees or more, a surface roughness of Ra1.6 μm or less, and a hardness of HV140 or more.

[0028] The contact angle with water is the contact angle specified by the sessile drop method of JIS (Japanese Industrial Standards, hereinafter the same) R3257:1999. Fig. 3 is a side view explaining the contact angle with water. The contact angle with water is the angle θ between the surface of the test piece 20 and a tangent line drawn from the contact point (point A) of the test piece 20, the water drop 21, and the air to the curved surface of the water drop 21.

[0029] Surface roughness Ra is the arithmetic mean roughness defined in JIS B601:2013. Hardness HV is the Vickers hardness defined in JIS Z2244-1:2020.

[0030] According to the configuration of the heating unit 14 according to this embodiment of the present invention, the surface of the plating layer 142, which is the inner surface of the heating unit 14, has a contact angle with water of 90 degrees or more and a surface roughness of Ra 1.6 μm or less, which prevents adhesion of powder particles due to condensation. FIG. 4 shows a water droplet 21 on the plating layer 142. In the state of FIG. 4, the contact angle θ with water is larger than 90 degrees, and the releasability and water repellency of the water droplet 21 are improved. From the viewpoint of further improving the releasability and water repellency, the contact angle θ with water is more preferably 100 degrees or more.

[0031] In addition, the surface of the plating layer 142 has a hardness of HV140 or more, so that it is hard and resistant to wear. This not only prevents the inclusion of foreign matter due to worn material, but also prevents the increase in the surface area of ​​the inner surface due to wear, and prevents a decrease in the flow rate and internal pressure, thereby extending the life of the device 1.

[0032] Furthermore, the heating part 14 is resistant to thermal deformation due to the configuration in which the inner surface of the metal tube 141 is coated with a plating layer 142, so that the heating temperature can be increased. In addition to being simple in structure, this configuration has high strength, so that the weight can be reduced by making the wall thinner.

[0033] The plating layer 142 is not limited as long as it satisfies the requirements of a contact angle with water of 90 degrees or more, a surface roughness of Ra1.6 μm or less, and a hardness of HV140 or more. In contrast, the hardness of PTFE (fluororesin, the same applies below) is extremely low, and it is not possible to ensure a hardness of HV140 or more (see Comparative Example 2 below).

[0034] Table 1 shows the contact angle, surface roughness, and hardness for Comparative Examples 1 and 2 and Example 1. In Table 1, the values ​​in parentheses for the contact angle, surface roughness, and hardness indicate target values. [Table 1]

[0035] In Comparative Example 1, the entire cross section of the heating part is stainless steel, and the target values ​​for hardness and surface roughness can be achieved, but the target value for contact angle cannot be achieved. In Comparative Example 2, the entire cross section of the heating part is PTFE, and the target values ​​for contact angle and surface roughness are achieved, but the target value for hardness cannot be achieved. Comparative Example 2 is too soft to evaluate the hardness by Vickers hardness, but it is clear that the hardness is significantly lower than the target value.

[0036] In Example 1, a plating layer containing fluororesin particles was applied to a metal substrate, and the target values ​​for contact angle, surface roughness, and hardness were all achieved. The amount of fluororesin particles is optional, and plating that can achieve all the target values ​​can be selected from general-purpose products.

[0037] Here, as described above, the device 1 is set so that the mixed gas of the condensable gas and the powder / granular material 10 flows at a flow velocity of 200 m / sec or less. If the flow velocity is greater than 200 m / sec, the flow of the powder / granular material 10 also becomes faster, making it difficult for the powder / granular material 10 to adhere to the heating section 14, and the need for measures to prevent adhesion becomes less. In other words, this embodiment is configured to effectively prevent the powder / granular material 10 from adhering. This makes it possible to reduce the length of the heating section 14 required to ensure the residence time of the powder / granular material 10, and prevents the device 1 from becoming large in size.

[0038] Fig. 5 is a schematic diagram of a heating or sterilization treatment apparatus 1' (hereinafter referred to as "apparatus 1'") according to another embodiment of the present invention. The same components as those in Fig. 1 are given the same reference numerals and their description will be omitted. In Fig. 1, the heating unit 14 is arranged horizontally, whereas in Fig. 5, the heating unit 14 is arranged vertically. Even in this configuration, by adopting a configuration in which the above-mentioned plating layer 142 is applied to the inner surface of the heating unit 14, it is possible to realize a heating unit 14 that is hard, resistant to wear, and resistant to thermal deformation while preventing adhesion of powder or granular material 10, as in the apparatus 1 in Fig. 1.

[0039] In the device 1 shown in FIG. 1 and the device 1' shown in FIG. 5, it is preferable that the heating unit 14 is grounded (earthed). In the device 1 shown in FIG. 1, an earth 143 is added to the heating unit 14. The grounding is sufficient as long as the heating unit 14 is substantially grounded, and the grounding point is not limited to the heating unit 14. In the device 1' shown in FIG. 5, an earth 183 is added to the cyclone 18. These configurations can prevent the adhesion of powder and granular material to the inner surface of the heating unit 14 due to static electricity. This not only prevents quality deterioration and foreign matter contamination due to the generation of lumps and scorching, but also prevents the surface area of ​​the inner surface of the heating unit 14 from being reduced due to adhesion, prevents an increase in flow rate and internal pressure, and makes cleaning easier.

[0040] While the configuration in which the plating layer 142 is applied to the inner surface of the heating section 14 has been described above, a plating layer may also be applied to the inner surface of the pressure reducing section 15 in Fig. 1 and Fig. 5. In this configuration, similar to the heating section 14, the surface of the plating layer has a contact angle with water of 90 degrees or more, a surface roughness of Ra1.6 µm or less, and a hardness of HV140 or more. With this configuration, similar to the heating section 14, the pressure reducing section 15 also has the effect of preventing adhesion of the powder / granular material 10, while having high hardness, being resistant to wear, and being resistant to thermal deformation.

[0041] 1 and 5, the pressure reducing section 15 uses a thin tube, but a rotary valve may be used instead. The pressure reducing section 15' shown in Fig. 6 uses a rotary valve as the pressure reducing section. The rotary valve of the pressure reducing section 15' is connected to the heating section 14, and is composed of a supply port 151 for the powdered or granular material 10, a discharge port 152 for the powdered or granular material 10, a casing 153, and a rotor 155 that forms a plurality of pockets 154 in the casing 153 and rotates within the casing 153.

[0042] In this configuration, powder or granular material 10 supplied to supply port 151 is supplied to open pocket 154, transferred to discharge port 152 as rotor 155 rotates, and drops from pocket 154 which opens to discharge port 152. By changing the rotation speed of rotor 155, the time for which powder or granular material 10 is heated under pressurized conditions can be easily changed.

[0043] A plating layer 142 may be applied to the inner surface of the casing 153 and the surface of the rotor 155 which form the inner surface of the rotary valve. In this configuration, similar to the heating part 14, the surface of the plating layer has a contact angle with water of 90 degrees or more, a surface roughness of Ra1.6 μm or less, and a hardness of HV140 or more. With this configuration, similar to the heating part 14, the casing 153 and the rotor 155 can prevent adhesion of the powdered or granular material 10, while having high hardness, being resistant to wear, and being resistant to thermal deformation. EXAMPLES

[0044] The present invention will be described in more detail below with reference to examples. The apparatus configuration of the examples is the same as that of apparatus 1 shown in Fig. 1. The cross-sectional structure of heating section 14 is as shown in Fig. 2, and a plating layer 142 (Example 1 in Table 1 in this example) is applied to the inner surface of metal tube 141 (stainless steel tube in this example). Similarly to heating section 14, decompression section 15 is also a stainless steel tube with a plating layer applied to the inner surface. Other experimental conditions are as follows. Inner diameter of heating section 14 at the start of the experiment: 30.0 mm Inner diameter of pressure reduction section 15 at the start of the experiment: 15.0 mm Powder 10: Wheat flour, red pepper Water vapor pressure at the start of the experiment: 0.40MPa Processing time: 1 hour After the operation, the inside of the heating section 14 was checked, and no adhesion, burning or clogging was found for either the wheat flour or the red pepper. For comparison, the heating section 14 was composed of only a stainless steel tube with an inner diameter of 30.0 mm (without a plating layer), and the decompression section 15 was composed of only a stainless steel tube with an inner diameter of 15.0 mm (without a plating layer), and an experiment was conducted on a comparative example with the same configuration as the embodiment except for this. In the comparative example, the processing amount (discharge amount) gradually decreased after 5 minutes for wheat flour and after 3 minutes for red pepper, and partially burnt material began to be mixed in. In both cases, the heating section 14 was completely clogged after 2 minutes. When the inside of the heating section 14 was checked, the raw material was adhered to and burned on the stainless steel surface, and the inside of the tube was clogged. This comparative experiment confirmed the adhesion prevention effect of the powdered or granular material 10 according to the present invention.

[0045] The experiment with wheat flour of the above embodiment was continued, and the total processing time was 1600 hours. During this time, the operation was stopped, the device was cleaned, and the operation was restarted repeatedly. The water vapor pressure during operation did not change, and after 1600 hours of operation, the inner diameters of the heating section 14 and the decompression section 15 were measured to be 30.0 mm for the heating section and 15.0 mm for the decompression section, which were unchanged from the start of the experiment. For comparison, the heating section 14 was composed of a fluororesin tube with an inner diameter of 30.0 mm and a stainless steel tube reinforcing the fluororesin tube from the outside, and the decompression section 15 was composed of a fluororesin tube with an inner diameter of 15.0 mm and a stainless steel tube reinforcing the fluororesin tube from the outside, and the rest of the experiment was confirmed by an experiment using a comparative example with the same configuration as the embodiment. In the comparative example, although the flow rate of water vapor supplied was constant, the water vapor pressure during operation began to gradually decrease after 200 hours had passed, and by the time it reached 1600 hours, it had decreased to 0.31 MPa. After 1600 hours of operation, the inner diameters of the heating section 14 and the decompression section 15 were measured to find that they had expanded from the start of the experiment, being 30.1 mm for the heating section 14 and 16.5 mm for the decompression section 15. This comparative experiment confirmed the wear prevention effect of the heating section 14 and the decompression section 15 according to the present invention.

[0046] Although the embodiment and examples of the present invention have been described above, these are merely examples and may be modified as appropriate. For example, the device 1 and the device 1' may be any device equipped with a heating unit 14 that heat-treats the powder or granular material 10 with a condensable gas, and the shape and size of the heating unit 14 are not particularly limited. [Explanation of symbols]

[0047] 1,1' Heating or sterilization treatment device 11 Supply means 12 Powder input section 13 Condensable gas supply section 14 Heating section 142 Plating layer 143 Earth 15 Pressure reduction section (thin tube) 15' Pressure reducing section (rotary valve) 183 Earth

Claims

1. A supply means for supplying powder and granular material; a powder / granular material input section into which the powder / granular material is input from the supply means; A condensable gas supply unit that blows a condensable gas into the powder or granule; a heating unit that heats the powder or granular material by the condensable gas; a pressure reducing section that releases the mixture of the powder or granular material and the condensable gas into a space having a lower pressure than the heating section, The heating portion is made of metal, The inner surface of the heating portion is provided with a plating layer, The surface of the plating layer is The contact angle with water is 90 degrees or more. The surface roughness is Ra 1.6 μm or less, The hardness is HV140 or more, When the powder or grain is introduced into the condensable gas, in the heating section, the mixture flows under pressurized conditions at a flow rate of 200 m / sec or less, and heat of the condensable gas is transferred to the powder or grain due to a temperature difference between the powder or grain and the condensable gas, causing condensation on the surfaces of the powder or grain, and the powder or grain is released through the decompression section to a space with a lower pressure than the heating section, whereby the powder or grain is heated or sterilized.

2. 2. The heating or sterilization treatment device for powder or granular material according to claim 1, wherein an inner surface of the pressure reducing section is provided with a plating layer, and the surface of the plating layer has a contact angle with water of 90 degrees or more, a surface roughness of Ra 1.6 μm or less, and a hardness of HV 140 or more.

3. The heating or sterilizing treatment apparatus for powder or grain according to claim 1, wherein the pressure reducing section is formed of a thin tube.

4. The heating or sterilizing apparatus for powder or grain according to claim 1 , wherein the pressure reducing section is constituted by a rotary valve.

5. The heating or sterilizing apparatus for powder or grain according to claim 1 , wherein the heating unit is grounded.

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