JPS59210851A - Process for batchwise heat-treatment with steam - Google Patents

Abstract

PURPOSE:To enable the reduction of the heating time and energy consumption, by changing the ambient temperature within a range higher than the stationary treatment temperature until the surface temperature of the material to be heated reaches the stationary treatment temperature. CONSTITUTION:Steam is blasted through the steam-blasting pipe 2 into the heat- treatment chamber 1 containing the material 11 to be heat-treated, and the temperature of the material 11 is maintained at the stationary treatment temperature for a definite time interval. In the above batch-wise steam-heating process, the temperature of the atmosphere 12 in the chamber 1 is adjusted to a level sufficiently high compared with the stationary treatment temperature of the material 11 at the initial stage of heating, and is lowered gradually according to the increase of the temperature of the material 11 until the surface temperature of the material reaches the stationary treatment temperature, when the ambient temperature is adjusted to the stationary temperature. The process enables the shortening of the time for raising the temperature of the material to the stationary treatment temperature, the improvement in the efficiency of the heat- treatment operation, and the saving of the energy consumption.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a batch steam heat treatment method in which an object to be heated, such as food, is heated by being kept in a high-temperature steam atmosphere for a certain period of time. The present invention relates to a batch-type steam heat treatment method that can shorten heating time and save energy by maintaining the ambient temperature at a higher temperature than the total steady-state treatment temperature and changing it appropriately until the steady-state treatment temperature is reached.

Generally, in the batch type steam heat treatment method, as shown in FIG.
The heat treatment is performed by increasing the temperature of the object 11 to be heated and maintaining it at a predetermined steady-state treatment temperature for a certain period of time. Since this is a treatment method, heat is transferred from the steam to the object to be heated by film condensation or droplet condensation, and the surface of the object to be heated 11 is formed into a liquid or droplet-like temperature boundary layer (hereinafter referred to as a boundary layer). )13.

By the way, in the conventional batch-type steam heat treatment method, as shown in FIG. (c) In the final stage (C), the temperature of the atmosphere 13 in the heat treatment tank is set to the same temperature as the steady-state treatment temperature to of the object to be heated 11, so that the steam is transferred to the object to be heated. heat transfer? Due to the presence of the protective film 13, there were problems such as a longer heating time until the temperature of the object to be heated 11 reached the steady processing temperature to, lowering work efficiency and increasing heating energy consumption. .

The present invention was devised to solve the above-mentioned problems.
The purpose of the present invention is to provide a batch-type steam heat treatment method that can improve work efficiency and save energy by shortening the heat treatment time in a kettle to reach a steady treatment temperature without degrading the quality of the object to be heated.

In order to achieve the above objectives, as a result of various studies, we found that the atmospheric temperature inside the heat treatment tank does not directly affect the temperature rise of the object to be heated, that is, there is a boundary between the heat from the steam and the surface of the object to be heated. Focusing on the fact that heat is transmitted indirectly to the object to be heated through the film, the ambient temperature is maintained at a temperature higher than the entire steady-state processing temperature until the surface temperature of the object to be heated rises to the steady-state processing temperature. As a result, the present invention has been completed.The structure of the present invention is that steam is blown into a heat treatment tank containing a material to be heated, and the temperature of the material to be heated is maintained at a constant processing temperature for a certain period of time. In the batch-type steam heat treatment method that maintains the temperature at gradually decreases as
Seventh, the gist of the present invention is a batch-type steam heat treatment method characterized in that the steady-state treatment temperature is set when the surface temperature of the object to be heated reaches the steady-state treatment temperature.

An embodiment of the present invention will be described below based on the drawings. FIG. 3 shows a heat treatment apparatus for carrying out a batch type steam heat treatment method according to an embodiment of the present invention. A pipe 2 and a temperature sensor 3ff are disposed, and an electric valve 5. It is equipped with an automatic temperature regulator 8 to which a pressure reducing valve 6 and a pressure gauge 7 are attached, and which automatically controls changes in the ambient temperature within the heat treatment tank 1. The automatic temperature controller 8 is
Control of the temperature change of the surrounding air in the heat treatment tank 1 Compares the detection signal from the program setting section 9 and temperature detector 3 programmed in advance with the setting signal from the program setting device 9 to fully control the opening/closing of the electric valve 5 A valve control section 10 is configured to output a signal.

Therefore, in the batch type steam heat treatment method of this embodiment, as shown in FIG. In this step, steam at a temperature sufficiently higher than the steady-state treatment temperature to of the object to be heated 11 is blown from the natural air blow-off pipe 2 in the heat treatment tank 1 shown in FIG. Set to tl (to<ti) which is sufficiently higher than to. In this case, although the temperature of the object to be heated 11 rises rapidly, it does not suddenly exceed the steady processing temperature tof due to the film 13 covering its surface, and therefore the quality of the object to be heated 11 is not affected in any way. It's not a joke. Next, during the middle heating period (B), as the temperature of the object to be heated 11 rises toward the steady-state processing temperature to, the temperature of the atmosphere 12 is increased to a temperature higher than the steady-state processing temperature to and lower than the initial heat processing temperature t1. t2 (to<t2<t
At the end of heating (0, that is, when the surface temperature of the object to be heated 11 reaches the steady processing temperature to, the temperature of the atmosphere) 2 is also maintained as to for a certain period of time. In this embodiment, an automatic temperature controller 8 is used to program atmospheric temperature changes in the heat treatment tank 1 in advance in the program setting unit 9, and a temperature detector:
3 outputs a detection signal according to the temperature in the heat treatment tank 1 and a setting signal from the program setting section 9, which are input into the motor-operated valve control section 10 and compared, and the output control signal is used to control the motor-operated valve 5. Opening/closing operation: Opening/closing in response to temperature changes in the heat treatment tank 1 to control the steam Fi− blown into the heat treatment tank 1 to adjust the temperature from the above atmospheric temperature tl according to the properties of the object to be heated 11. Proportional temperature change leading to
Since the temperature is automatically adjusted in stages or in other ways, the temperature can be easily changed to the optimum conditions without any erroneous operation.

Figure 5 shows the temperature of the object to be heated (a) and ambient air temperature (b) in the conventional heat treatment method in the north mentioned above, as well as the temperature of the uninvented object. Class 7J [I Hj+% Temporal sharpening k of the temperature of the treated material (c) and the ambient temperature (d) in the heat treatment method according to one embodiment
The graph below shows that the steady processing temperature to and the conventional atmosphere temperature are set at 80°C, and the atmosphere temperature in the heating initial JQj of the present invention is set at 90°C. The short shoes of the heat treatment time in the invention are recognized.

As described above, in the batch steam heat treatment method of the present invention, the ambient temperature is set to be sufficiently higher than the steady treatment temperature at the initial stage of heating, and gradually lowered as the temperature of the object to be heated increases. This method is characterized in that the steady processing temperature is set when the surface temperature of the object reaches the steady processing temperature, so the temperature of the object to be heated rises rapidly in the initial stage of heating, and the presence of a film prevents the steady processing temperature from reaching the steady processing temperature. Since the heat treatment does not exceed gold, the heat treatment time can be shortened without deteriorating the quality of the object to be heated, thereby making it possible to improve heat treatment efficiency and save energy.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the state in which the object to be heated is being heat-treated in the heat treatment tank, Fig. 2 is an explanatory diagram showing the state of temperature change in the conventional heat treatment process, and Fig. 3 is an explanatory diagram showing the state of temperature change in the conventional heat treatment process. A configuration diagram of a heat treatment apparatus for carrying out the batch type steam heat treatment method of the present invention, FIG. 4 is an explanatory diagram showing the state of temperature change in the heating process of the present invention, and FIG. 5 is a diagram of the conventional and present invention. This is a gnof that shows the temperature change over time. 1... Heat treatment tank 2... Steam blowing pipe 10.
... Automatic temperature controller 12 ... Atmosphere patent applicant Isope Noodle Machine Co., Ltd. Representative Patent attorney 1) Toshibe Bebe

Claims (2)

[Claims] (1) In a batch steam heat treatment method in which steam is blown into a heat treatment tank containing a heat treatment object and the temperature of the heat treatment object is maintained at a steady processing temperature for a certain period of time,
The ambient temperature in the heat treatment tank is set at a temperature sufficiently higher than the steady-state treatment temperature of the object to be heated at the initial stage of heating, and is gradually lowered as the temperature of the object to be heated rises. A batch-type steam heat treatment method, characterized in that the temperature is set to the steady-state treatment temperature when the temperature reaches the steady-state treatment temperature. (2) The scope of claim 1 is characterized in that changes in the atmospheric temperature in the heat treatment tank are automatically controlled by a pre-written program until the surface temperature of the object to be heated reaches the steady treatment temperature. Batch steam heat treatment method.