JPH0619342B2 - Vacuum drying tester - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vacuum drying tester, and more specifically, for selecting vacuum drying conditions prior to full-scale operation,
The present invention relates to a vacuum drying tester for performing a trial vacuum drying treatment on a relatively small amount of raw materials prepared in a liquid, slurry or paste form.

2. Description of the Related Art In recent years, many kinds of processed food materials and instant foods have been marketed with the diversification of eating habits. In such a food processing field, the consumer maintains the solubility and immediacy when using the product as a cooking ingredient at a predetermined level, and the final product is free from deterioration of quality and deterioration of ingredients. Various atmospheric dryers and vacuum dryers are used for the purpose of imparting restoration properties. Focusing on the fact that it is relatively easy to maintain the solubility of a product as a cooking ingredient at a good level among such dryers, the fields of use of vacuum dryers are rapidly increasing. Spray dryers and freeze dryers are known as general-purpose vacuum dryers.
The former has a low drying cost, but the solubility and quality retention performance of the product or the component change prevention performance is somewhat inferior.
The latter is accompanied by the problems of complicated structure and soaring drying cost due to the adoption of freezing and sublimation processes. Here, the development of a vacuum belt dryer has been demanded as a means for solving the practical problems recognized in the spray dryer and the freeze dryer. The vacuum belt dryer is provided with a heating zone and a belt transfer device in a vacuum container, and supplies a food material prepared in a liquid form, a slurry form, or a paste form in a thin film form on an endless transfer belt,
The rotation of the endless conveyor belt guides the food material to the heating zone, and vacuum drying is performed under relatively low temperature drying conditions. At this time, the food material placed in a thin film on the belt undergoes a rapid evaporation phenomenon of the water contained therein, and the food material expands and forms a large number of vent holes inside. , Sent to the crusher as a porous intermediate product.

Problems to be Solved by the Invention As can be understood from the above description, the vacuum belt dryer is
In terms of quality retention performance, component change prevention performance, and drying cost reduction performance, it is possible to exhibit performance far exceeding that of known spray dryers and freeze dryers, but vacuum drying should be performed. In order to cope with the diversification of food materials, it is necessary to further enhance the selection performance of drying conditions. On the other hand, in such a vacuum belt dryer, it is necessary to find the optimum drying conditions that match the characteristics of food materials before starting full-scale operation. The drying test is executed while changing the time, and the data of the drying time and the drying temperature applicable to the actual vacuum drying process are acquired.

However, since the vacuum belt dryer installed in the actual vacuum drying process runs the sample in a series of furnaces with different drying conditions, the drying conditions of each furnace should be carefully and arbitrarily adjusted. Was difficult.

The main object of the present invention is to eliminate the above-mentioned problems observed when a large vacuum belt dryer installed in an actual production line is diverted to the pre-pilot stage as a means for selecting drying conditions. It is to provide a vacuum drying tester.

Means for Solving the Problems In view of such an object, the present invention is a tester for setting vacuum drying conditions of raw materials prepared in a liquid form, a slurry form, or a paste form, and a vacuum container (1 ), A drying rack (2) made of a synthetic fiber cloth that is freely inserted into and pulled out from the inside, a heating / cooling plate (3) disposed below the drying rack (2), and the plate (3). ) Connected to the plate (3) by steam introduced from outside the system.
A first heat exchanger (10) for generating a heating medium to be supplied into
A second heat exchanger (11) which is connected to the plate (3) and generates a cooling medium to be supplied into the plate (3) by the cooling water sent from the chiller unit (9); Sequence function that is connected to the plate (3) and controls the heating medium or cooling medium introduced from the first and second heat exchangers (10) and (11) to control the temperature and operating time of the plate (3) A drying time and a drying temperature control device (4) having a temperature of the working medium is changed with time, and a sample in a stationary state is run under the same conditions as in the case where the sample is run and tested in a large vacuum dryer. The gist is a vacuum drying tester that reproduces and performs a vacuum drying process.

Action The temperature of the working medium introduced into the heating / cooling plate (3) arranged in the vacuum container (1) by operating the controller for the drying time and the drying temperature (4) is changed according to the type of sample. The data necessary for the actual operation is acquired by subjecting a relatively small amount of the stationary sample to a vacuum drying treatment which is changed with the passage of time.

Embodiment FIG. 1 is a front view with a part in section illustrating the overall structure of the device of the present invention. As shown in the figure, in the vacuum container (1), a drying rack (2) formed by stretching a synthetic fiber knitted fabric on a support frame is mounted so that it can be inserted and pulled out. A heating / cooling plate (3) for causing a heating / cooling medium to act on raw materials prepared in a liquid form, a slurry form, or a paste form to be vacuum-dried is disposed below. The heating / cooling plate (3) needs to be able to freely change the drying conditions, that is, the heating temperature, the cooling temperature or the drying time of the raw material according to the characteristics of the raw material. In 3),
A panel having a sequence relay for controlling the temperature of the heating medium or the cooling medium introduced therein and the operating time of the heating medium or the cooling medium is connected as a control device (4).

In the vacuum container (1), a heating medium or a cooling medium is circulated through a vacuum generator (5) and a heating / cooling plate (3) as a component of a vacuum drying system according to a conventional method.
It is connected to the medium circulation pipe (20) indicated by the thick line in the figure. In the medium circulation pipe (20), a first tube type for producing a heating medium by causing a heat exchange function between the steam introduced from outside the system and the medium circulating in the pipe (20) Alternatively, the cooling water and piping generated by the chiller unit (9) including the plate heat exchanger (10), the cooling water tank (6), the air cooling chiller (7), and the cooling water circulation pump (8) ( 20) A second tube type or plate type heat exchanger (11) for producing a cooling medium by causing a heat exchange function with a medium circulating in the medium, and a medium circulation pipe (20) A circulation pump (12) for circulating the medium is provided.

In the figure The pipe shown by is the steam pipe (21), The pipe shown by is the cooling water pipe (22). (23) is a solenoid valve provided in the steam pipe (21), (24) is a solenoid valve provided in the cooling water pipe (22), and the solenoid valve (23) (2
By selectively controlling opening and closing of 4) by the panel control device (4), a heating medium or a cooling medium is generated in the medium circulation pipe (20) to heat the heating / cooling plate (3), or Cooling.

By operating the vacuum generator (5), the inside of the vacuum container (1) can be maintained at a vacuum degree of about 10 Torr when the sample is dried. On the other hand, the vacuum container (1) is provided with an expansion tank (13) that promotes circulation of hot water by air pressurization, and a device (14) for supplying a sample prepared in a liquid, slurry or paste form. There is. The sample supply device (14) is a synthetic fiber cloth drying rack (2) mounted above the heating / cooling plate (3) in the vacuum container (1), and is a comparative object to be tested. A discharge nozzle mechanism for supplying a small amount of sample in a thin film form, and according to the first embodiment, a manual handle (15).
Alternatively, a lead screw (16) rotated by a motor (not shown), a slide bracket (19) screw-engaged with the lead screw and moving forward and backward along the axial direction thereof,
Sample discharge nozzle (1
7) and the raw material tank (18).
Further, according to the second embodiment, the slide bracket (19) performs a swinging motion or a rotating motion while moving forward and backward along the axial direction of the lead screw (16) to promote the spreading function of the sample. The drying shelf (2) is a thin film member having a breathable sample mounting surface with a weave or stitches formed by stretching a knitted fabric of synthetic fiber yarn on an appropriate support frame (not shown). Therefore, in addition to general properties such as strength, friction coefficient, heat resistance, etc., it improves the peelability of the sample after vacuum drying, and the heat of the heating medium or cooling medium through the weave and the stitches. In order to efficiently transfer energy to the sample, it is produced, for example, by subjecting a woven fabric of polyester multifilament yarn to a surface treatment with a resin such as silicone or polytetrafluoroethylene.

The end wall portion of the vacuum container (1) is openably and closably supported by a well-known lid and hinge mechanism, and the sample dried under vacuum is changed from a vacuum state in the vacuum container (1) to an atmospheric pressure released state. After switching, by opening the lid, the lid can be pulled out from the vacuum container (1) while being placed on the drying shelf (2).

Hereinafter, a usage example of the device of the present invention will be described based on an example of chicken soup having a weight of 60 g in an undried state.

After the drying shelf (2) was mounted inside the vacuum container (1), the sealed vacuum container (1) was maintained at a vacuum degree of about 10 Torr by activating the vacuum generator (5). In this state, the sample supply device (14) is activated, the paste stock solution of chicken soup is spread and placed on the drying shelf (2) in a thin film state, the feeding of the sample supply device (14) is stopped, and the sample is stopped. Then, it is introduced into the heating and cooling plate (3) from the first and second heat exchangers (10) and (11) by utilizing the sequence function of the controller for controlling the drying time and the drying temperature (4). The heating or cooling medium is switched over time, for example according to the embodiment shown in FIG. 2, the plate is first at 150 ° C. for 14 minutes, then 140 ° C. for 14 minutes, 120 ° C. for 9 minutes, and 40 ° C. for 4 minutes. (3)
The vacuum drying test was carried out by setting the heating characteristics with the temperature maintained. The chicken soup thus vacuum-dried is formed into a porous cake having a dry weight of 30 g, and placed on the drying shelf (2) by opening the vacuum container (1). It was taken out as it was. The obtained sample was then pulverized into granules according to a conventional method and sent to the subsequent quality test process.

EFFECTS OF THE INVENTION As can be understood from the above description, in the apparatus of the present invention, when vacuum drying conditions are selected for a relatively small amount of sample in the test process prior to full-scale operation, the drying conditions of the vacuum container are changed over time. Since it is set and tested, it is possible to reproduce the same conditions as when testing using a large vacuum dryer that has multiple built-in sections with different drying conditions arranged in the actual production process. Moreover, it is extremely easy and easy to set and change the drying conditions. Therefore, according to the present invention, the vacuum drying data required for full-scale operation can be accurately selected from the test results of a small amount of sample.

[Brief description of drawings]

FIG. 1 is a front view with a partial cross section illustrating the overall structure of the device of the present invention, and FIG. 2 is an orthogonal coordinate diagram showing an example of a test by the device of the present invention. (1) ... vacuum container, (2) ... drying rack, (3) ... heating and cooling plate, (4) ... control device for drying time and drying temperature.

Claims (1)

[Claims] 1. A tester for setting vacuum drying conditions of raw materials prepared in a liquid state, a slurry state, or a paste state, which is made of a synthetic fiber cloth that can be inserted into and pulled out from a vacuum container. A drying shelf, a heating / cooling plate disposed below the drying shelf, and a first heat which is connected to the plate and generates a heating medium to be supplied into the plate by steam introduced from outside the system. A second heat exchanger which is connected to the exchanger and which produces cooling medium supplied into the plate by cooling water sent from the chiller unit; 2 is composed of a drying time and drying temperature control device having a sequence function for controlling the temperature and operating time of the plate by adjusting the heating medium or cooling medium introduced from the heat exchanger. Vacuum drying tester and characterized by applying vacuum drying process to a sample of a stationary state by changing the temperature of the working medium over time.