JPH0146790B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention provides an apparatus for drying powder and granules such as synthetic resin raw materials and processed food raw materials before supplying the powder and granules to a synthetic resin molding machine or the like. Regarding.

(Prior Art) Conventionally, the following types of drying apparatuses are known as this type of drying apparatus.

(B) As shown in Japanese Utility Model Application Publication No. 47-12163, a single drying cylinder with a material supply port formed at one end and a material discharge port formed at the other end is installed horizontally, and inside this drying chamber there are 1 In addition to providing several screw shafts, a ventilation chamber was formed below the screw shaft via a sorting plate, and hot air was supplied from an external heat source to this ventilation chamber and discharged from above. thing.

(b) As shown in Japanese Utility Model Application Publication No. 47-28664, screw conveyors operated by a prime mover are horizontally arranged in several stages, one end of the top screw conveyor is connected to a supply funnel, and each screw conveyor is The conveyors are alternately connected by connecting pipes, and the lowest screw conveyor has a discharge pipe at its tip, while a heater container connected to a blower is installed above each guide trough that accommodates each screw conveyor. (heat source), a plurality of heater tubes are installed separately for each guide tub via hot air supply branch pipes, and hot air is supplied to each screw conveyor through a large number of small holes drilled in the heater tubes, and then to each screw conveyor. Heaters branched from the heater container are provided at the lower part of the guide tubs to heat each guide tub.

(c) As shown in Japanese Utility Model Application Publication No. 53-35472, a plurality of drying cylinders each having a material supply port at one end and a material discharge port at the other end are connected to the discharge port of the upper drying cylinder and the supply port of the lower drying cylinder, respectively. The drying cylinders are arranged horizontally in a storage chamber in multiple stages, upper and lower, in a communicating state, and a screw shaft having a stirring and transporting function for the material is rotatably installed horizontally in each drying cylinder. A plurality of heat sources are connected in communication so that the hot air from the heat source flows through the exhaust pipe above the uppermost drying cylinder, and a partition plate 1 is provided in the insulating chamber so as to house each of the drying cylinders, The heating amount of the multiple drying cylinders can be individually controlled by opening and closing the air volume adjustment damper provided on the partition plate.

(Problem to be solved by the invention) However, according to the above conventional example (a), only one screw shaft is provided to stir and transfer the material, so the transfer distance and residence time of the material are lengthened. If this is desired, the screw shaft must be made longer, which results in the inconvenience of a large, horizontally long drying device.

In addition, the heater (heat source) is not installed directly under the screw shaft, but instead supplies hot air from a single heat source installed outside to the screw section through the ventilation chamber, making it difficult to dry the material. There is a limit to the power of heat energy.

Moreover, there is no structure for changing the heating temperature of the material by a heater or changing the rotational speed of the screw shaft by a drive source at the start of drying or during the transfer of the material, so this method is difficult to dry. It is not possible to perform more appropriate drying depending on the physical properties of the material to be used. Moreover, no contrivance has been made to greatly expand the adjustment range of material drying time and heating temperature by mutually multiplying the rotational speed of the screw shaft and the temperature ratio of the heater.

In the hot air supply method according to the conventional example (b), the heater is supplied to the upper part of each guide tub that accommodates the screw conveyors arranged in multiple stages through a hot air supply branch pipe that is separately installed in one heater container (heat source). Each tube is provided,
Hot air is supplied to the guide tub from the large number of small holes in each heater tube, and since each guide tub is made of heat-resistant metal or other non-porous material, the hot air supplied to each guide tub is transferred to the other guide tubs. It is not intended to be supplied to the guide tube. In other words, the hot air is directed from below to above (or in the opposite direction).
It is uneconomical in terms of thermal energy because it does not fluidize towards the end of the process.

Further, each heater pipe has disadvantages such as not only the piping work of the hot air supply branch pipe branching from one heater container is troublesome but also requires a large number of pipes.

Furthermore, each screw conveyor is rotated at the same rotational speed by one drive source, and the hot air supplied from each heater tube is also supplied from the same heater container. The temperature of the hot air supplied to Yukon Bear is the same, and hot air with different temperatures is not supplied.

Therefore, this conventional example (b) also applies to the conventional example (a).
Similarly, it is not possible to change the drying temperature or the screw rotation speed (material transport speed) individually during the transfer of the material, so it is not possible to perform more appropriate drying according to the physical properties of the material, etc. . Moreover, no contrivance has been made to greatly expand the adjustment range of material drying time and heating temperature by mutually multiplying the rotational speed of the screw shaft and the temperature ratio of the heater.

In the conventional example (c), the heating amount of a plurality of drying cylinders can be individually controlled. However, individual temperature control in this case (c) is performed by adjusting the volume of hot air from a single heat source using an air volume adjustment damper on a partition plate installed inside the insulating room.
It is difficult to immediately fine-tune the temperature difference between the drying cylinders. Moreover, the heater (heat source) is not installed directly under the screw shaft, but instead supplies hot air from a single heat source installed outside to the screw shaft via an insulating chamber (blow chamber). There is a limit to the amount of thermal energy required to dry the material. In this case as well, like the conventional examples (a) and (b),
No measures have been taken to greatly expand the adjustment range of material drying time and heating temperature, such as by multiplying the rotational speed of the screw shaft and the temperature ratio of the heater.

The present invention aims to provide a solution that solves the problems of the conventional examples (a), (b), and (c) above.

(Means for Solving the Problems) The present invention, as a means for solving the above problems, will be described with reference to FIGS. 1 and 2, which are one embodiment. Two drying cylinders 1a and 1b each having a discharge port 3 at the other end are horizontally arranged in upper and lower stages with the discharge port 3 of the upper drying cylinder 1a and the supply port 2 of the lower drying cylinder 1b communicating with each other, Inside each of the drying tubes 1a and 1b, an upper screw shaft 4a or a lower screw shaft 4b having a stirring action and a transporting action for the material is rotatably installed horizontally, and an upper screw shaft 4a or a lower screw shaft 4b, which has a material stirring action and a transporting action, is horizontally installed, and the upper screw shaft 4a or the lower screw shaft 4b is installed horizontally so as to be freely rotatable. In a drying device for powder and granular materials in which hot air is made to flow through an exhaust pipe 11 above the cylinder 1a, ventilation plates 7a and 7b are formed at the bottoms of the upper drying cylinder 1a and the lower drying cylinder 1b, and both ventilation An upper heater 8a and a lower heater 8b are provided directly below the plates 7a and 7b,
An air pipe 10 is connected to one side of the lower storage chamber housing the lower heater 8b, and two partition plates 10a, 10a through which the lower heater 8b is inserted are connected to the air pipe 10. 10a,1
The other end of 0a is connected to the ventilation plate 7b at approximately equal intervals,
Furthermore, by directly adjusting the rotational speed of the upper screw shaft 4a and the lower screw shaft 4b, and the temperature of the upper heater 8a or lower heater 8b, the temperature ratio in the upper drying cylinder 1a and the lower drying cylinder 1b can be changed as appropriate. The structure is as follows.

(Function) Ventilation plates 7a and 7b are formed on the bottoms of the upper drying tube 1a and the lower drying tube 1b, and an upper heater 8a and a lower heater 8b are provided below both ventilation plates 7a and 7b. , lower drying cylinder 1b
When air is blown from the air pipe 10 below, the air is heated to a set temperature by the heater 8b, and then the ventilation plate 7
b, the hot air dries the material in the lower drying cylinder 1b. The dried hot air passes through the upper ventilation plate 7a and is further heated to a set temperature by the upper heater 8a, thereby drying the material in the upper drying cylinder 1a. In this way, the material is first dried in the upper drying tube 1a and then secondarily dried in the lower drying tube 1b, starting from below the lower drying tube 1b to the upper drying tube 1a.
Fluidized drying is performed by flowing hot air all the way to the top of the dryer, so the material is dried evenly and efficiently.

In addition, by directly adjusting the rotational speed of the upper screw shaft 4a and the lower screw shaft 4b, and the temperature of the upper heater 8a or lower heater 8b, the temperature ratio in the upper drying cylinder 1a and the lower drying cylinder 1b can be changed as appropriate. be able to. That is, by changing the rotational speed of the upper screw shaft 4a and the lower screw shaft 4b, the material can be transferred to the upper drying tube 1.
a. Adjusting the time for transport in the lower drying cylinder 1b and, in turn, the drying time by the upper heater 8a or the lower heater 8b to match the optimal conditions for drying,
It can improve the drying efficiency of materials.

By changing the heating temperature of the upper heater 8a and the lower heater 8b, the heating temperature during material transfer can be set to match the optimum conditions for drying, and the drying efficiency of the material can be similarly improved.

By multiplying the rotation speed of the former screw shaft and the temperature ratio of the latter heater,
Since the range of adjustment of material drying time and heating temperature can be greatly expanded, the above effects can be further enhanced.

(Example) An example of the present invention will be described below based on FIGS. 1 and 2.

Reference numeral 1 designates a drying cylinder consisting of two upper drying cylinders 1a and a lower drying cylinder 1b, which are horizontally arranged in two stages, upper and lower, with their axes horizontal. Each of the upper drying tube 1a and the lower drying tube 1b has a material supply port 2 at one end and a material discharge port 3 at the other end. It communicates with the supply port 2 to form a U-shaped material passage. Each upper drying cylinder 1a
In the lower drying cylinder 1b, an upper screw shaft 4a and a lower screw shaft 4b, each having a screw blade 4' for stirring and transporting the material, are rotatably disposed horizontally. Below the lower drying cylinder 1b is a blower pipe 10 connected to a blower source B such as a blower.
However, exhaust pipes 11 are connected above the upper drying tube 1a, and the hot air blown from the blower tube 10 is transferred to the lower drying tube 1b and the upper drying tube 1a.
The flow passes through the exhaust pipe 11 through the upper drying tube 1a.
And the material in the lower drying cylinder 1b is dried.

At the bottoms of the upper drying tube 1a and the lower drying tube 1b, porous ventilation plates 7a and 7b are provided so as to form the bottom surface of each drying tube, and below these ventilation plates 7a and 7b, respectively. Upper heater 8
a, a lower heater 8b is provided.

The upper surface of the lower drying cylinder 1b is covered with an air-permeable partition plate 9 made of the same material as the ventilation plate 7b, except for the supply port 2 which serves as a communication passage with the discharge port 3 of the upper drying cylinder 1a, The heated air that escapes from the upper part of the lower drying cylinder 1b through the partition plate 9 is reheated by the upper heater 8a and is supplied to the upper drying cylinder 1a from the vent hole 7 at the bottom of the upper drying cylinder 1a. There is.

One side of the lower storage chamber housing the lower heater 8b (left side in Figure 1) has an air outlet 10' that communicates with an air source B such as a blower, and connects the lower drying cylinder 1b and the upper drying cylinder 1a. A blower pipe 10 that supplies air heated by the lower heater 8b is connected. The inside of this blower pipe 10 is divided into three parts as shown in FIG. 1 by two partition plates 10a, each of which has a lower drying tube 1b inserted through it, so that the air sent to the lower drying tube 1b is distributed over almost its entire length. constructed to be uniform. The above two partition plates 10a, 1
The upper edge of 0a is connected to the ventilation plate 7b at approximately equal intervals.

The exhaust gas from the exhaust pipe 11 is discharged to the outside air in the embodiment, but the exhaust gas from the exhaust pipe 11 is
The exhaust port 11' can also be connected to the intake port of the air source B. With this configuration, the heating air heated by both heaters 8a and 8b is circulated and used, which has the advantage of saving thermal energy.

By directly adjusting the rotational speed of the upper screw shaft 4a and the lower screw shaft 4b and the temperature of the upper heater 8a or the lower heater 8b, the temperature ratio in the upper drying cylinder 1a and the lower drying cylinder 1b can be changed as appropriate. be.

The amount of material filled in the upper drying cylinder 1a is about 3 kg, the lower drying cylinder 1b is about 12 kg, the drying temperature of the lower drying cylinder 1b heated by the lower heater 8b is about 90°C, and the upper drying cylinder reheated by the upper heater 8a. 1a is about 150℃
The actual length of the upper and lower drying tubes 1a and 1b is each 600 mm, and the air flow rate is approximately 4 m ³ per minute.
In this example, the inventors conducted an experiment in which the upper screw shaft 4a in the upper drying cylinder 1a was set to rotate 4 times per minute, and the lower screw shaft 4b in the lower drying cylinder 1b was set to rotate once per minute. According to the results, significant effects of the present invention were observed.

In addition, 12 is a material supply hopper connected to the upper part of the material supply port 2, 13 is connected to the lower part of the material discharge port 3 and is formed between the outer plate and the back wall 10b of the blower pipe 10, A chute part with a connection port 13a opened on the back side, 14 a motor with a reducer attached to one side of the device as shown in Fig. 2, 15 fixed to the outer end of the upper screw shaft 4a in the upper drying tube 1a. The chain 17 that rotates the sprocket 16 in accordance with the motor 14 is a chain that similarly drives the sprocket 18 of the lower screw shaft 4b of the lower drying cylinder 1b. The sprocket 16, 18
Upper drying tubes 1 are used with different diameters.
The rotational speed of b is made to be different.

An example of how the above embodiment is used will be described below.

The material falling from the material supply hopper 12 to the supply port 2 of the upper drying cylinder 1a is stirred in the vertical direction by the screw blades 4' of the rotating upper screw shaft 4a and transferred to the left in FIG. 1 until the set temperature is reached. While being heated, it moves from the communication passage with the lower drying cylinder 1b to the lower drying cylinder 1b. Then, it moves to the right in the lower drying cylinder 1b while being stirred in the vertical direction, reaches the desired degree of dryness after a residence time of about 15 minutes in the drying cylinder 1b, and reaches the chute part 13 from the discharge port 3 to the connection port 13a. is discharged from the device.

Note that in the above embodiment, the drying tubes 1b are arranged in two rows, upper and lower, in order to reduce the installation area of the device and to further increase thermal efficiency, but the drying tubes 1b may be installed at a slight inclination to the horizontal. Needless to say.

(Effects of the Invention) According to the present invention, (1) the rotational speed of the upper screw shaft and the lower screw shaft, and the temperature ratio of the upper heater or the lower heater can be directly adjusted so that the inside of the upper drying cylinder and the lower drying cylinder can be Since the temperature ratio of the materials is configured to be changeable as appropriate, the heating temperature can be changed for each material at the start of drying or during transfer, or the rotational speed of the screw shaft can be changed for each material, etc. More appropriate drying can be performed depending on the physical properties of the material to be dried. Moreover, since the temperatures of both the upper and lower heaters can be directly and individually adjusted, the heating temperature can be finely adjusted with high precision.

By multiplying the rotation speed of the former screw shaft and the temperature ratio of the latter heater,
Since the range of adjustment of material drying time and heating temperature can be greatly expanded, the above effects can be further enhanced.

On the other hand, conventional examples (a), (b), and (c) do not have such a structure or effect.

(2) In this invention, a ventilation plate is formed at the bottom of the upper drying cylinder and the lower drying cylinder, and an upper heater and a lower heater are separately provided directly below both ventilation plates, so that the screw shaft can be Compared to the conventional example (a), which has only one piece, it is possible to significantly lengthen the transfer distance and residence time of the material with a piece of almost the same size. Since there are both heaters, the conventional example
Thermal efficiency for drying the material is much better than in the case of (a) and (c), which use a single heat source provided externally.

In the conventional example (b), the hot air supplied to each guide tub is not supplied to other guide tubs, but only the guide tub facing each heater is heated and dried, whereas the present invention An air pipe is connected to one side of the lower storage chamber housing the lower heater, and two partition plates through which the lower heater is inserted are connected to the air pipe, and the other end of the partition plate is connected to the ventilation plate. Because they are connected at equal intervals, the heated air from both the upper and lower heaters passes through the ventilation plates installed above and dries the material in each drying cylinder, achieving reuse of thermal energy. Fluidized drying with high thermal efficiency is possible.

Furthermore, in contrast to the conventional example (b), in which each heater pipe is not only troublesome but also requires a large number of pipes, the piping work for the hot air supply branch pipes branching from one heater container is complicated, whereas the upper and lower heaters of the present invention The structure as in the conventional example (b) is not necessary, and since the drying cylinder is provided directly below both the upper and lower parts through the ventilation plate, the structure is simple and no piping work is required.

Thus, according to the present invention, it is possible to obtain a drying apparatus in which the material is dried uniformly, the drying time is shortened, and the drying efficiency is high.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a front view thereof, and FIG. 2 is a right side view thereof. 1a... Upper drying tube, 1b... Lower drying tube, 2
... Supply port, 3 ... Discharge port, 4a ... Upper screw shaft, 4b ... Lower screw shaft, 7a, 7b
... Ventilation plate, 8a ... Upper heater, 8b ... Lower heater, 10 ... Air pipe, 10a ... Partition plate, 1
1...Exhaust pipe.

Claims (1)

[Claims] 1. Two drying cylinders 1a and 1b each having a material supply port 2 at one end and a material discharge port 3 at the other end, an upper drying cylinder 1a.
The discharge port 3 of the lower drying tube 1b and the supply port 2 of the lower drying tube 1b are horizontally installed in upper and lower stages with the supply port 2 of the lower drying tube 1b communicating with each other.
Inside b, there is an upper screw shaft 4a or a lower screw shaft 4b having a stirring action and a transporting action for the material.
In the apparatus for drying powder and granular materials, the drying apparatus for powder and granular material is arranged horizontally so as to be rotatable, and hot air flows through from the blower pipe 10 below the lower drying barrel 1b to the exhaust pipe 11 above the upper drying barrel 1a, the upper drying barrel Ventilation plates 7a and 7b are formed at the bottom of the drying cylinder 1a and the lower drying cylinder 1b, and an upper heater 8a is provided directly below both the ventilation plates 7a and 7b.
A lower heater 8b is provided, and a blower pipe 10 is connected to one side of the lower storage chamber housing the lower heater 8b.
Two partition plates 10a, 10a are connected, and the other end of the partition plates 10a, 10a is connected to the ventilation plate 7b.
The upper drying cylinder 1a and the lower drying cylinder 1b are connected to the upper drying cylinder 1a and the lower drying cylinder 1b at approximately equal intervals, and by directly adjusting the rotational speed of the upper screw shaft 4a and the lower screw shaft 4b, and the temperature of the upper heater 8a or the lower heater 8b, respectively. A drying device for powder or granular material, characterized in that the temperature ratio within the drying device can be changed as appropriate.