JPH0450251Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a device for detecting deviation of an endless conveyor belt in a vacuum belt dryer.

BACKGROUND ART In recent years, vacuum dryers have been used as manufacturing equipment for pharmaceuticals and food materials, especially as drying processing equipment for them. For example, with the diversification of dietary habits, many types of processed food ingredients and instant foods are on the market. Various types of atmospheric drying equipment and vacuum drying equipment are used to maintain instant processability at a predetermined level and to give the final product resilience without deterioration of quality or deterioration of ingredients. There is. Among these, attention has been paid to the fact that it is relatively easy to maintain the solubility of processed food materials used as cooking ingredients at a good level, and the field of use of vacuum drying equipment is rapidly increasing. In other words, spray dryers and freeze dryers are known as general-purpose food drying equipment, but while the former has low drying costs, it has problems with the solubility of processed food materials due to restrictions on drying temperature. The quality retention performance and the prevention performance of component change are somewhat inferior, and the latter is accompanied by problems such as a complicated structure of the equipment and a rise in drying costs due to the adoption of freezing and sublimation processes. There is.

Therefore, there has been a demand for the development of a vacuum belt dryer as a means of solving the practical problems observed in the above-mentioned spray dryers and freeze dryers.

A vacuum belt dryer has a constant rate drying area, a decreasing rate drying area, and a cooling area sequentially arranged in a vacuum container, and is equipped with an endless conveyor belt device to convey these materials to be dried. The material to be dried prepared in the form of a slurry or paste is distributed and fed onto the endless conveyor belt, and the rotation of the endless conveyor belt moves the material to be dried into the constant rate drying zone, the decreasing rate drying zone, and the cooling zone. We will gradually introduce
It is configured to perform vacuum drying under drying conditions at a relatively low temperature.

By vacuum drying, the moisture contained inside the material to be dried, which is supplied onto the endless conveyor belt, rapidly evaporates, and the material to be dried expands and forms many ventilation holes, forming a porous material. The intermediate product is sent to a crushing device consisting of a rotating blade and a wire mesh provided at the end of the rotation path of the endless conveyor belt,
It falls into the extraction chamber in a granular state. In response to the above requirements, the applicant of the present invention has previously proposed an improved vacuum belt dryer in Japanese Unexamined Patent Publication No. 61-223480.

Problems to be solved by the invention As can be understood from the above explanation, the vacuum belt dryer is superior to the known spray dryer in terms of ease of maintaining product quality, ability to prevent component changes, and ability to reduce drying costs. However, since a belt device for conveying the material to be dried is installed inside the vacuum container, it is difficult to maintain stable drying conditions. There are many points that require improvement.

For example, if the endless conveyor belt used as a means of conveying the material to be dried is meandering or shifting due to uneven elongation, the constant speed feeding function of the material to be dried is inhibited, resulting in uneven drying of the product. This causes variations in quality. Furthermore, if the amount of deviation of the endless conveyor belt exceeds the permissible limit, the material to be dried may spill from the conveyor surface and the conveyor itself may be damaged, and the vacuum belt dryer may have to be stopped for a long time to repair the problem. There must be. For this reason, not only the quality of the product but also the productivity of the vacuum drying process itself is significantly reduced.

In order to eliminate the problems caused by such meandering and misalignment of the endless conveyor belt, attempts have been made to install electrical sensors and optical sensors inside the vacuum container as means for detecting meandering and misalignment. Since the vacuum inside the vacuum container is maintained at a vacuum level of around 10 Torr, there is a risk of electrical discharge or shot when using an electric sensor, and when using an optical sensor, there is a risk of the material being dried. When cleaning the inside of the vacuum container at the time of switching, the cleaning liquid will be scattered, and there is a risk of malfunction due to adhesion of the cleaning liquid.

The main object of the present invention is to provide a solution to the above-mentioned problems found in vacuum belt dryers, particularly vacuum belt dryers that use electrical or optical sensors as means for detecting deviation of an endless conveyor belt. It is about providing.

Means for Solving the Problems As a means for achieving the above object, the present invention provides a vacuum belt dryer in which an endless conveyor belt is stretched in a vacuum container, (a) on the side of the rotation path of the endless conveyor belt; (b) a pneumatic sensor disposed in the vacuum container with the actuator directly facing the deviation detection lever; (c) ) A vacuum belt whose detection system includes a pneumatic/electrical relay that converts a deviation detection signal of the endless conveyor belt transmitted from the pneumatic sensor, which is disposed outside the vacuum container, into an electrical signal. A device for detecting deviation of an endless conveyor belt in a dryer is provided.

Function: A shift signal of the endless conveyor belt detected by a swing-type shift detection lever provided inside the vacuum container is provided to the outside of the vacuum container via switching of the air flow path of a pneumatic sensor. This signal is transmitted to the pneumatic/electrical relay, and the ON/OFF control of this pneumatic/electrical relay causes the tensioned roll of the endless conveyor belt to perform an offset correction operation.

Embodiment FIG. 1 is a longitudinal sectional view illustrating the overall structure of a vacuum belt dryer according to the present invention, FIG. 2 is a perspective view illustrating the main structure of an endless conveyor belt deviation detection device, and FIG. FIG. 2 is an explanatory diagram of a connection state between a pneumatic sensor and a pneumatic/electrical relay.

The vacuum belt dryer is equipped with a hot water generator 4 consisting of an expansion tank 1, a pump 2, and a heat exchanger 3. Below the belt 6, there are a first heating plate 7a, a second heating plate 7b, and a third heating plate 7c that function as a heating medium for the material to be dried using hot water sent from the hot water generator 4.
are sequentially arranged along the rotating direction of the endless conveyor belt 6. In the illustrated vacuum belt dryer, the first heating plate 7a and the second heating plate 7b constitute a constant rate drying device, and the third heating plate 7c constitutes a lapse rate drying device. On the other hand, the third
A cooling plate 9 is provided downstream of the heating plate 7c for cooling the material to be dried with cold water supplied from the chiller unit 8.

The inside of the vacuum container 5 is operated by a vacuum generator 10 consisting of a cold trap and a vacuum pump.
The vacuum level is maintained at around 10 Torr. At the front end of the vacuum container 5, there is provided a container for uniformly distributing and supplying a material to be dried prepared in the form of a liquid, slurry, or paste, such as a concentrated liquid of chicken extract, onto the endless conveyor belt 6 in the form of a thin film. A dispersion nozzle 11 is provided at the rear end of the vacuum container 5, and a reciprocating shearing device is provided at the rear end of the vacuum container 5 for the purpose of crushing the material to be dried which has been subjected to a predetermined drying process by constant speed movement of the endless conveyor belt 6. Preklashar 12 with a blade
A secondary crushing device 15 consisting of a rotary blade 13 and a wire mesh 14 is also provided.

The material to be dried that has been crushed into granules is transferred to a product take-out chamber 21 equipped with a vacuum lock mechanism 20.
It falls into the interior and is stored under vacuum conditions.

As shown in FIGS. 2 and 3, the endless conveyor belt offset detection device A includes a swing-type offset detection lever 16 disposed on the side of the rotation path of the endless conveyor belt 6; A pneumatic sensor 17 is disposed inside the vacuum vessel 5 with the actuator 17a directly facing the deviation detection lever 16, and the pneumatic sensor 17 is disposed outside the vacuum vessel 5.
It is composed of a pneumatic/electrical relay 18 that converts a deviation detection signal of the endless conveyor belt 6 transmitted from the endless conveyor belt 6 into an electric signal.

To explain in more detail, the deviation detection lever 16
is supported so as to be able to swing around a pivot shaft 16a, and is constantly pressed toward the endless conveyor belt 6 through the bias of a compression spring 19.
When the endless conveyor belt 6 is not offset, a predetermined gap is maintained between the side edge of the endless conveyor belt 6 and the rotating roller type detector 16b attached to the tip of the offset detection lever 16. has been done.

On the other hand, the pneumatic sensor 17 is composed of a pneumatic switching valve, has an actuator 17a protruding toward the side of the deviation detection lever 16, and has a compressed air introduction pipe 17b, an exhaust pipe 17c, and the pneumatic/electrical An air supply pipe 17d to the relay 18 is connected.

Since the device A of the present invention is configured as described above, when the endless conveyor belt 6 does not deviate or meander, the rotating roller type detector 16b of the deviate detection lever 16 and the endless conveyor belt 6 It is held in a non-contact state with the side edge of. Therefore, the actuator 17a is not pressed by the deviation detection lever 16, and compressed air supplied from an external compressed air source (not shown) into the pneumatic sensor 17 through the introduction pipe 17b is completely closed. As a result, the exhaust pipe line 17c and the air supply pipe line 17d are brought into electrical continuity. In this state, the pneumatic sensor 16 does not send out a bias signal, so the pneumatic/electrical relay 18 is turned OFF, and the distance between the axes is controlled by the step motor attached to the drive roller 6a of the endless conveyor belt 6, fine adjustment screws, etc. No offset correction operation occurs in the adjustment mechanism (not shown).

On the other hand, if the endless conveyor belt 6 is deviating or meandering, the deviating detection lever 16
The rotating roller type detector 16b is connected to the endless conveyor belt 6.
is pressed by the side edge of the actuator 17
a is pushed in. As a result, the compressed air flow path is conducted to the air supply pipe 17d side, and the pneumatic/electrical relay 18 is activated.
Switched to ON state. As a result, an electrical deviation detection signal is transmitted from the pneumatic/electrical relay 18, and the axle distance adjusting mechanism connected to the pneumatic/electrical relay 18 is activated, and the axes of the driving roller 6a and the driven roller 6b are finely adjust the parallelism of When the amount of deviation of the endless conveyor belt 6 is reduced to below the allowable value by finely adjusting the parallelism of the axis, a gap is created between the rotating roller type detector 16b and the side edge of the endless conveyor belt 6. , the pushing state of the actuator 17a by the deviation detection lever 16 is released. As a result, the pneumatic sensor 1
The flow path of the compressed air introduced into 7 is the air supply pipe 17
The changeover is made from the d side to the exhaust pipe line 17c side, and when the pneumatic/electrical relay 18 is turned OFF, the inter-axle distance adjustment mechanism is stopped.

Effects of the Invention As can be understood from the above explanation, the present invention automatically corrects the meandering and deviation of the endless conveyor belt stretched within the vacuum container. Furthermore, in this invention, there are no electrical or optical sensors installed inside the vacuum container, so there is no discharge, shoot, or malfunction, and highly safe operating conditions can be maintained for a long period of time. It becomes possible to continue. In this way, a significant effect is observed in improving the stability of production and drying conditions.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view illustrating the overall structure of the vacuum belt dryer according to the present invention, Fig. 2 is a perspective view illustrating the main structure of the device of the present invention, and Fig. 3 is a pneumatic sensor and pneumatic/electric FIG. 3 is an explanatory diagram of a connection state of a relay. 5... Vacuum container, 6... Endless conveyor belt, 16
...Misalignment detection lever, 17...Pneumatic sensor,
18...Pneumatic/electrical relay, A...Misalignment detection device.

Claims (1)

[Scope of utility model registration request] In a vacuum belt dryer in which an endless conveyor belt is stretched in a vacuum container, a swing-type offset detection lever disposed on the side of the rotation path of the endless conveyor belt; A pneumatic sensor disposed inside the vacuum container with the actuator directly facing the object, and a deviation detection signal of the endless conveyor belt transmitted from the pneumatic sensor disposed outside the vacuum container. Sky converted into electrical signal/
A device for detecting deviation of an endless conveyor belt in a vacuum belt dryer, characterized in that a detection system is configured by an electric relay.