JPS6338801A - Method and device for supplying steam for heating food - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for supplying heating stem air suitable for a food manufacturing method in which food is heat-processed using steam heat, and an apparatus for supplying stem air for that purpose. be.

[Conventional technology]

Traditionally, steam has been widely used as a heating heat source in the production of steamed foods such as Japanese sweets, sekihan, and manju, meat foods such as ham and sausage, and processed foods such as kamaboko and hampen. It is used.

In the past, when steaming food using steam heat, the method used was to place a steamer containing food over a pot and add the steam generated by heating the pot to the food in the steamer, but recently, factory production In order to be adaptable to mass production methods, steam obtained from high-pressure steam generators such as boilers is increasingly used.

[Problem 3 to be solved by the invention: The method of using steam obtained from a boiler for steaming food has a long history of using steam obtained by heating a pot, compared to the method of using steam obtained by heating a pot. It has the advantage of being economical in that the rate of wasteful loss of steam energy is low.

However, the use of steam obtained by a boiler for the production and processing of food was not originally considered from the perspective of using steam, which was to use tea for the steaming of food, but only as a steam generator. This method has been considered from the outside perspective, and is unreasonable for steaming food products, resulting in several problems with product quality.

The first problem is that the steam obtained from the boiler is generally superheated steam with a cage pressure of 5 to 7 kg/cut G and a saturation temperature of 158°C to 169°C, which is high temperature and pressure. For steaming, the temperature is too high to be used as it is, so the steam is reduced to a pressure of about 1 to 2 kg/cut G and a saturation temperature of about 130°C using a pressure reducing valve, which does not interfere with the continuous operation of the boiler. This means that it must be fed into the food steamer at a reduced temperature.

-Processing products under these conditions when manufacturing Japanese sweets on a boat means that steam pressure to a certain extent can speed up the flow of steam around and inside the product, so the processing time can be shortened. It is believed that good quality can be obtained. However, in reality, using steam at a high temperature of 100°C or higher to steam food products may result in
The problem is that it causes changes in physical properties such as surface burns, scorching, and dryness, which changes the heat transfer rate and moisture permeability of the affected area, and has an unfavorable impact on quality conditions such as the appearance of "uneven spots" on the product at a later date. Includes points.

By the way, when considering the process of steaming food, theoretically, the supplied steam envelops the food, the moisture generated through heat exchange with the food forms a surface film on the food, and the heat and moisture are transferred to the food. This is done by penetrating into the inside of the body. In this case, if the temperature of the steam heat is appropriate, the moisture on the surface of the food has a low permeability to the inside and re-evaporates, allowing the steaming process to be performed appropriately. In other words, there is no need to spray high-temperature, high-pressure steam on anything, as long as the temperature is right so that the steam can surround the food and raise the temperature of the food. , 4
Foods of good quality can be obtained by supplying saturated steam at around 100°C at a low pressure of about kg/kg/kg/kg.

On the other hand, no matter how much you try to reduce the pressure of steam produced by a general-purpose boiler using a pressure reducing valve, the boiler itself is originally intended to obtain high-temperature, high-pressure steam of about 5 to 7 kg/cut G. To,
The range in which the pressure can be reduced is at most 3 to 2 kg/c1δG, and as mentioned above, the pressure is 0.1, which is common in food steaming.
It is difficult to continuously obtain fujiki with a reduced pressure of about 0.4 kg/cnlc in terms of operational adjustment of the boiler, and there is a problem that the boiler cannot be operated.

Furthermore, the second problem that can be considered when steam obtained from a boiler is used for food manufacturing and processing is that the can cleaning agent added to the boiler water to protect the boiler body gets mixed into the steam. This poses a significant problem to food quality.

As is well known, the water injected into the boiler is treated with a deoxidizing agent that turns hard water into soft water to prevent deterioration of iron heat exchangers and prevent snail buildup. Y
? ;Since canning agent is usually highly alkaline water with a pH of about PHII to 13, when boiler water mixed with this canning agent is vaporized and used for thinning food, the highly alkaline water will directly adhere to the food. This will significantly affect the quality of the food. In addition, this can cleaning agent not only affects the quality of food, but also contains a trace amount of heavy metal substances that are harmful to the human body, which is undesirable from a food hygiene perspective.

[Means for solving problems]

In order to solve the above-mentioned problems when using steam from a boiler for food manufacturing and processing, the present invention uses high-pressure steam from a boiler as a heat exchanger to produce a product that does not contain any impurities such as can cleaning agents. This allows low-pressure steam of pure water to be obtained continuously and efficiently and economically. Furthermore, as a means for achieving this, the present invention heats impurity-free water supplied into a tank using a heat exchanger that uses high-pressure steam heat from a boiler placed above the tank to generate low-pressure steam. This low-pressure steam is introduced into a steam separation chamber equipped with a barrier plate that blocks the flow, and the excess moisture is separated by contact with the barrier plate in the vapor separation chamber, and the steam is saturated at a temperature of 110°C or less with an appropriate amount of moisture. It is characterized by supplying steam to the food heating means.

[For production]

By supplying a certain amount of impurity-free water through the tank and into the steam generation tube in the upper heat exchange chamber, and introducing high-pressure steam from the boiler into the heat exchange chamber, the upper part of the steam generation tube is heated from 0.2 to 0. .5kg/c++I G
low pressure steam is generated and introduced into the upper steam storage chamber. The steam stored in the steam storage chamber is introduced into the steam separation chamber on the side, but this steam separation chamber has a barrier plate that blocks the flow of steam flowing from the direction of the steam storage chamber. If the vapor comes into contact with this barrier, the moisture contained in the steam will adhere to the surface of the barrier plate. The steam from which excess moisture has been removed by the barrier plate passes under the barrier plate and leaves the steam separation chamber at a gauge pressure of 0.4 kg/cta G.
The steam is supplied as low-pressure steam with a saturation temperature of about 109.43° C. and moderate moisture, containing no impurities, into a food heating means such as a steamer, and used as food processing heat.

A water level sensor is placed in the steam generation tube in the heat exchanger from the upper steam storage chamber, and as steam is generated and supplied, water is constantly replenished from the lower water storage tank to a predetermined level in the steam generation tube. Ru.

〔Example〕

Next, the steam generator used in the steam supply method according to the present invention will be explained with reference to an embodiment shown in the drawings. As shown in FIG. Rather than supplying directly to the food heater 3,
The low pressure generated by being introduced into the heat exchanger 4 and used as a heating medium for the impurity-free water 5 stored in the heat exchanger 4 and heated by the heating medium in the heat exchanger 4. Steam 6 is supplied to food heater 3.

Further, the specific configuration of the steam generator is as shown in FIG. 2, as shown in FIG.
and the heat exchanger located above this tank 8) (3
4, and a steam storage chamber 9 located above this heat exchanger 4.
and a steam separation chamber 10 connected to the side of the steam storage chamber 9 via a conduit 11.

In the heat exchanger 4, both upper and lower ends of an outer cylinder 12 are closed off by end plates 13, and a plurality of steam generation tubes 14a, 1 are arranged between both end plates 13.
4b, 14 cm -- are penetrated through the pipes so that both ends thereof are opened to the outside of the end plate 13. Also, the upper end of the outer cylinder 12 has a steam inlet 15, and the lower end has a steam outlet 16.
is opened, high pressure steam from the boiler 1 is introduced into the outer cylinder 12 from the introduction port 15 via the supply pipe 17,
Each steam generation pipe 14a, 14b from inside the lower water storage tank 8
, 14C... After heating the water, it returns to the boiler 1 via a return pipe 18 connected to the steam outlet 16.

A water storage tank 8 connected to the water supply line 7 is fixed to the lower end Fi13 of the heat exchanger 4 through a flange 19 at the upper end so as to be removable if necessary, and has a heater 20 and a heater 20 inside. It has a temperature sensor 21.

The steam storage chamber 9 disposed at the upper part of the heat exchanger 4 is also removably fixed to the upper end of the heat exchange chamber 4 via a flange 22 at the lower end, and a level sensor 23 is installed at the upper end of the interior. Electrodes 24 having different lengths from the level sensor 23 are inserted into some of the steam generation tubes 14b in the heat exchanger 4. These level sensor electrodes 24 are connected to the tap water supplied into the water storage tank 8.
Each steam generation tube 14a, 14b, 14c of the heat exchanger 4...
- A signal is given to the valve 25 in the water supply line 7 to stop the supply of water to the water storage tank 8 when the water reaches a predetermined level. Furthermore, steam generation pipes 14a, 14b, 1
4c... is heated by the surrounding high-pressure steam and evaporates, and the water level in the steam generation pipe decreases, the level sensor 23 activates the valve of the water supply line 7 to compensate for the insufficient water level in each pipe. 25 is opened, and a predetermined amount of water is sequentially supplied into the water storage tank 8.

Steam separation chamber 1 communicating with steam storage chamber 9 via conduit 11
0, a barrier plate 28 extending perpendicularly to the conduit 11 from a cover plate 27 attached to the upper flange 26 connects the separation chamber 10.
The flow path 30 is isolated between the bottom plate 29 of the steam introduction chamber 10a with the barrier plate 28 in between.
A low-pressure steam supply pipe 31 leading to the food heater 3 is connected to the side wall of the steam supply chamber 10b on the opposite side. Further, a drain port 32 is provided in the bottom plate 29 of the vapor separation chamber 10, and a return pipe 33 is connected between the drain port 32 and the water storage tank 8.

In the figure, 34 is a safety valve installed in the steam storage chamber 9, 35 is a pressure setting switch installed in the steam separation chamber 10, 36 is a thermometer, and 37 is an electromagnetic valve installed in the high-pressure steam supply pipe 17 from the boiler 1. Showing the valve.

Tap water containing no impurities from the water supply line 7 passes through the water storage tank 8 to the steam generation pipes 14a, 14 in the heat exchanger 4.
b, 14c..., the valve 25 of the water supply line 7 shuts off, and the boiler 1
High-pressure steam flows into the heat exchange chamber 4 through the supply pipe 17 and heats the surroundings of each steam generation pipe 14a, 14b, 14C, etc., and the water in the pipe is heated and evaporated. The steam generated in each of these steam generation tubes is indirectly heated by high-pressure steam from boiler I, so the generated steam has a gauge pressure of 0.2 to 0.5 kg/ci G and a saturation temperature of 105°C to 110°C. It is low pressure saturated steam at around ℃. After this low-pressure steam is stored in the upper steam storage chamber 9, it is introduced into the steam separation chamber 10 via the conduit 11, and the barrier plate 28
Excess moisture contained in the steam adheres to the barrier plate 28, and is transferred to the supply pipe 31 as moderately moist saturated steam.
It is continuously supplied to the food heater 3 through.

For example, when a work process is to be canceled in the morning, the supply of high-pressure steam from the boiler 1 to the heat exchanger 4 is stopped, but at that time the heater in the water storage tank 8 is activated, and a temperature sensor is used to stop the operation for a long time. Also, the water temperature in the tank is maintained at a set temperature of about 95 to 100°C. As a result, when we start supplying high-pressure steam to the heat exchange chamber 4 in order to start work again in the afternoon, the preheated hot water is heated by the high-pressure steam, so the desired low-pressure steam can be efficiently supplied immediately after work starts. can be supplied.

〔effect〕

As described above, according to the steam supply method of the present invention, tap water that does not contain harmful substances can be used as a heat source for steaming and heating foods as low-pressure saturated steam. Food heating can be performed without using steam containing harmful substances, and extremely favorable results can be obtained from the viewpoint of food hygiene.

In addition, the steam obtained by this steam generator is generated by indirectly using high-pressure steam from a boiler in a heat exchanger, so it is less likely to be used for food than when it is generated by direct heating with an open flame. Low-pressure saturated steam with moderate moisture suitable for heating processing can be efficiently and continuously generated, resulting in "surface burns".
It is possible to produce foods of good quality that do not suffer from the negative effects of burnt or dryness.

Furthermore, since this steam generator uses high-pressure steam from the boiler as a heat source, food manufacturing factories can use the boilers that have been used in the past without discarding them and add this equipment to them, resulting in superior quality products. It has the advantage of being able to manufacture products. In addition, this device is configured so that the heat exchanger can be separated from the water storage tank and steam storage chamber as necessary, so after a predetermined period of operation, the inside of the heat exchanger is periodically removed and the inside of each steam generation pipe is cleaned. It has the advantage of being easy to clean and suitable for management.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the basic structure of a steam generator according to the present invention, and FIG. 2 is a sectional view showing the specific structure of the device. 1... Boiler, 2... High pressure steam, 3... Food heater, 4... Heat exchanger, 5... Water for steam generation, 6...
...Low pressure steam, 7...Water supply line, 8...Water storage tank, 9...Steam storage room, 10...Steam separation room, 11
... Conduit, I2 ... Outer cylinder, I3 ... End plate, 14a, 14b, 14c ... - Steam generation pipe, 17 ...
High pressure steam supply pipe, 18.33... Return pipe, 20... Heater, 21... Temperature sensor, 23... Reher sensor,
24... Electrode, 28... Barrier plate, 30... Channel,
31...Low pressure steam supply pipe.

Claims (4)

[Claims] (1) The impurity-free water supplied into the tank is heated by a heat exchanger that uses high-pressure steam heat from a boiler placed above the tank to generate low-pressure steam, and this low-pressure steam is made to flow. Saturated steam at a temperature of 110° C. or lower with appropriate humidity, from which excess moisture has been separated by contact with the barrier plate in the vapor separation chamber, is supplied to the food heating means by introducing it into a steam separation chamber equipped with a barrier plate. A method for supplying steam for heating food, characterized by: (2) A water storage tank with a heater and a temperature sensor is placed below, and a steam storage chamber is placed above, sandwiching a heat exchange chamber into which high-pressure steam from the boiler is introduced, and inside the heat exchange chamber. A plurality of steam generation pipes communicating between the lower tank and the upper steam storage chamber are passed through, a level sensor is extended from the steam storage chamber into some of the steam generation pipes, and a level sensor is extended from the steam storage chamber to the side of the steam storage chamber. A device for supplying steam for heating food, characterized in that a steam separation chamber having a barrier plate inside which blocks the flow of steam from a steam storage chamber is connected to one side via a conduit. (3) The food heating steam supply device according to claim 2, wherein the water storage tank, the heat exchanger, and the steam storage chamber are integrally connected so that they can be separated as necessary. (4) The food heating steam supply device according to claim 2, wherein a return pipe is connected between the steam separation chamber and the water storage tank to return the water separated in the steam separation chamber to the water storage tank.