JP2005152695A - Process for drying processed foods containing organic residues generated from food residues or water treatment equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent lowering of drying capacity by preventing a treating object from sticking to a heating surface of an indirect heating type dryer, and to prevent an increase in agitation power or noise generation due to stuck matter. <P>SOLUTION: When the treating object 20 is charged into a vessel body from a hopper 1, before charging into the vessel or in a drying vessel, the treating object is covered with slaked lime or mixed with it. Thus, the treating object 20 is prevented to the utmost from sticking to an agitator and the vessel body by an assistant in assistant-mixed sludge 22, when the treating object is sent to the downstream side, while being agitated by the agitator. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for drying a processed product and an indirect heating type drying apparatus, and more particularly to a technique suitable for drying a processed product containing a food residue or an organic substance generated from a water treatment apparatus as a component.

In general, food residues or processed products containing organic substances generated from a water treatment apparatus are reduced or reused by vaporizing and evaporating water contained therein. At that time, in order to evaporate and evaporate, hot air is blown into the container and the hot air and the processed product are directly contacted to dry, or a container or the like is heated by a heat medium, and the heated surface and the processed product are heated. An indirect heating type drying method is employed in which the product is brought into contact with the substrate and dried.
The indirect heating type drying apparatus that employs the indirect drying method has advantages such as low operating costs compared to the direct heating type drying apparatus that employs the direct drying method.

In a conventional indirect heating type dryer, a processed product is put into a container heated by a heat medium, and a heated stirrer mounted inside the container is rotated so that the processed product and the heating surface are rotated. An apparatus for improving the contact efficiency and drying the processed material while feeding it to the discharge port side has been proposed (see, for example, Patent Document 1).
JP 2001-153559 A

  By the way, in the above-described conventional indirect heating type drying apparatus, the processed product is made to come into contact with the heating surface to evaporate and remove moisture contained in the processed product. If it is attached to the surface of a heated stirrer or the inner wall of the drying container body, the heat transfer rate will be hindered and the processing capacity will be reduced, or the resistance of the processed material will cause stagnation and load on the stirrer. In the case of remarkable increase, there was a problem that operation was impossible.

  The present invention has been made in consideration of such circumstances, and its purpose is to maintain the heat transfer rate at a predetermined level by preventing the treatment object from adhering to the heating surface where heat transfer is performed. Another object of the present invention is to provide an indirect heating type drying method capable of preventing the generation of stagnation noise and the increase in the load on the stirrer.

In order to achieve the above object, the present invention proposes the following means.
In an indirect heating type dryer that heats and drys a processed product while stirring the processed product, by adding slaked lime to the processed product, the processed product is prevented from adhering to the heated surface in the drying container, and the slaked lime is absolutely dry. Addition within the range of 10% or more and 100% or less with respect to the weight of the treated product is characterized in that the deposition is effectively prevented, and a means for mixing the treated product and slaked lime is provided, and slaked lime is added to the treated product. Then, an indirect heating type drying method comprising means for supplying the slaked lime to the drying container or adding the slaked lime directly to the drying container and mixing the processed product in the drying container.

According to the invention of claim 1, in order to prevent the treated product from adhering to the inner wall of the drying container heated by the heat medium or the surface of the stirrer by covering or dusting the surface of the treated product with slaked lime, Suppresses heat transfer rate and increases the load on the stirrer, so that even if the operation is continued, the decrease in drying processing capacity and the increase in stirring power are kept to a minimum. The effect that it can process is acquired.
At this time, since slaked lime, which is a stable inorganic substance, is used as an auxiliary agent, it does not cause chemical changes even when mixed with sludge and food residue treatment products, and may promote the generation of off-flavors (bad odors). There is also an effect that the quality of the processed material is not changed.

According to the second aspect of the invention, the greater the amount of the additive added, the greater the effect of preventing the deposition. However, the amount of discharge increases as it is discharged together with the dried processed product.
However, when slaked lime is used for the treated product, it is possible to obtain an effect that the deposition can be greatly reduced even with an addition rate as low as 10% to 100% per dry weight.
In other words, if the amount of slaked lime added to the sludge or food residue treatment is less than 10% per absolute dry weight, the anti-adhesion effect cannot be obtained, and 100% per absolute dry weight. If more is added, the amount of discharge becomes large.
In addition, although the addition rate of slaked lime is previously determined using a similar experimental machine, it is necessary to vary the addition amount within the above range depending on the quality of the processed material.

  According to the third aspect of the present invention, the slaked lime is directly added to the processed product in the drying container and then stirred by the stirring unit in the drying container before supplying the processed product to the drying container. By covering or dusting the surface of the object with slaked lime, it is possible to prevent the treatment object from adhering to the heating surface.

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are views showing an indirect heating type drying apparatus to which a processed product drying method according to the first embodiment of the present invention is applied. FIG. 1 shows a processed product supplied from a hopper to a drying container body. FIG. 2 is an explanatory view showing a hopper.
In FIG. 1, a processed product 20 includes a food residue or an organic material generated from a water treatment device, and the processed product 20 is an indirect heating type drying apparatus 10 (hereinafter simply referred to as “drying”) of this embodiment. It is supplied to the container main body 11 (drying container main body) of the drying apparatus 10 through the hopper 1 of “apparatus”.
When the processed product 20 is supplied to the container main body 11 (drying container main body) of the drying apparatus 10 through the hopper 1, the processed product 20 is required for drying from the inner wall 11 of the container main body heated by the heat medium and the stirrer 12. Is supplied to the outlet side by the agitator 12 while evaporating moisture, and is discharged from the outlet 13 in a dry state. The stirrer 12 is heated by a heat medium such as steam, and is provided so as to be rotatable around an axis by a driving source (not shown) so that the processed material 20 can be dried while being stirred and fed downstream. It has become.

  The treated product 20 handled in this embodiment is a food residue, for example, a processed meat product such as a ham that has expired, a side dish made of seafood, or a food that contains sugar and is easily burned by heating. In addition to this, for example, an organic substance such as cellulose is used as a main component.

In such a drying method of the processed product 20, when the processed product 20 is put into the container main body 11 of the drying apparatus 10 from the hopper 1, as shown in FIG. By mixing in the hopper 1 together with the auxiliary 21, the auxiliary mixed sludge 22 is generated. When the auxiliary mixed sludge 22 generated in the hopper 1 is supplied to the container main body 11 as indicated by an arrow A shown in FIG. 1 and sent to the downstream side while being stirred by the stirrer 12, the auxiliary mixed sludge is mixed. The processed product 20 dried by the auxiliary agent 21 in 22 is prevented as much as possible from adhering to the inner wall of the container body and the stirrer 12.
In the illustrated drying apparatus 10, a premixing process is performed in advance to be mixed with the auxiliary agent 21 for preventing adhesion. Therefore, in the hopper 1 for supplying the processed material 20 to the container body 11, A mixing processing means (not shown) is used in which an auxiliary agent 21 for preventing adhesion is mixed with the processed material 20 to generate an auxiliary mixed sludge 22.

As such an auxiliary 21, slaked lime that does not cause a chemical change in the treated product 20 when mixed with the treated product 20, and does not generate malodor (unpleasant odor) or smoke is suitable. This has been confirmed in various experiments. And this adjuvant is set so that it may add at a certain ratio on the basis of the absolute dry weight of a processed material. And the addition amount of the adjuvant 21 is sufficient in the range of 10% or more and 100% or less of the weight when the processed product is dried to 0% moisture.
For example, when a processed product 20 containing 90% moisture is subjected to a dry treatment of 1000 kg / hr, the weight of the dried product to 0% moisture (referred to as the absolutely dry weight) is 10% to 100%, that is, 10 to 100 kg / hr. After the slaked lime is added to the treated product in the hopper, the slaked lime is put into the drying container 11 to prevent the treated product from being deposited on the heating surface.
Here, the addition rate of slaked lime is determined in advance by an experiment using a similar dryer smaller in scale than the drying device 10.

At this time, the processed product 20 to which the auxiliary agent has been added is transferred to the downstream side while being stirred and heated by the stirrer 12, but since the auxiliary agent is covered with the processed product, the container inner wall 11 and the stirrer 12 are heated. The treated product is prevented from adhering to the surface.
That is, since the outer surface of the processed product is coated with an auxiliary agent and does not have adhesiveness, the dried processed product is prevented from being attached to the outer surface of the stirrer 12.
This prevents the dried processed product from adhering to the inner wall 11 of the container and the outer surface of the stirrer 12, so that the heat transfer rate is maintained well and the friction resistance between the adherend and the tip of the stirrer is reduced. Since the increase of the resulting load is suppressed, it is possible to prevent a decrease in drying processing capacity and an increase in power.

The example which mixed the processed material 20 and the slaked lime 21 in advance, and supplies them to the container main body 11 was shown in FIG.1 and FIG.2. Inside the container body 11, stirrers 12 and 12 e are rotatably provided, and a plurality of stirrers 12 are provided on the stirring shaft 15 along the axial direction as a hollow disk.
The slaked lime 21 may be directly added to the drying container 11 and mixed while stirring and transporting with a stirrer equipped with a stirring blade 12e mounted inside. Selected.

The stirring shaft 15 has a cylindrical shape, and the inside thereof communicates with each stirrer 12.
In the stirring shaft 15, one end portion (left side in FIG. 1) protruding from the container body 11 is connected to a drive source (not shown) through a gear 16, and the other end (right side in FIG. 1) has steam as a heat medium. A steam inlet portion 17 is provided for taking in.
The steam introduced into the stirrer 12 is subjected to heat exchange and becomes drain (hot water). The drain flows into the stirrer shaft 15 and is discharged from the opposite side of the stirrer shaft 15, and the stirrer 12 is introduced into the stirrer 12. Heated by steam.
In the figure, reference numeral 13 denotes an exhaust port, 18A denotes an exhaust port for evaporated water, and 18B denotes an air inlet port intentionally introduced as necessary.

  Moreover, although the example using only slaked lime was shown as the auxiliary agent 21, it is needless to say that other components may be mixed with the auxiliary agent whose main component is slaked lime. In addition, as the processed material 20, organic substances, such as a food residue and a cellulose, are made into a main component.

  Table 1 shows Example 1 in which the indirect heating drying method according to the present embodiment is applied to a paddle type indirect heating drying apparatus 10 and Example 2 in which the indirect heating drying apparatus 10 is applied to a disk type. Table 5 shows.

In Example 1 applied to the paddle-type indirect heating type drying apparatus 10, as shown in Tables 1 to 3, when no slaked lime is added, the temperature of the processed product 20 hardly rises, and the processed product It can be seen that the moisture contained in 20 is difficult to evaporate and the processed product 20 is not dried well.
Furthermore, it can be seen that the stirring power of the stirrer 12 is always high and excessive resistance is generated.
On the other hand, when 17% of slaked lime is added to the absolute dry weight, the temperature of the processed product 20 also rises well, the water contained in the processed product 20 evaporates, and the processed product 20 is dried well. You can see that.

Furthermore, it turns out that stirring power is reduced as operation time passes.
That is, in Example 1, by adding the treated product 20 with slaked lime, it can be seen that the treated product 20 is dried in a short time and that the stirrer 12 can be stirred well without causing great resistance. .

In Example 1 applied to the disk-type indirect heating type drying apparatus 10, as shown in Table 1, Table 4, and Table 5, when slaked lime is not added to the processed product 20, It turns out that a water | moisture content does not evaporate easily and the processed material 20 is hard to dry.
Furthermore, when slaked lime is not added, it turns out that stirring power increases greatly on the way, and is always operating with high power.
On the other hand, when 50% of slaked lime is added to the absolute dry weight, the content of water contained in the processed product 20 is reduced in a short time, and the processed product 20 is well dried. I understand.
Moreover, even when the processed product 20 is dried, the stirring power is stable without increasing, and it can be seen that the processed product 20 is dried without being attached to the stirrer 12.
That is, in Example 2, it can be seen that, by adding the treated product 20 with slaked lime, the treated product 20 is dried in a short time, and the stirrer 12 can be satisfactorily stirred without causing great resistance. .

  According to the present invention, the treated product is prevented from adhering to the stirrer or the container main body, the drying treatment capacity of the treated product is prevented from being lowered, and the increase in power can be prevented, so that it can be used industrially. Sex is recognized.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the indirect heating type drying apparatus to which the drying method of the processed material which concerns on 1st Embodiment of this invention is applied, Comprising: It is a whole explanatory drawing of the partial fracture | rupture by which a processed material is supplied to a container main body from a hopper. is there. It is explanatory drawing which shows a hopper.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hopper 10 Indirect heating type dryer 11 Container body 12 Stirrer 20 Processed material 21 Adhesion prevention aid 22 Auxiliary mixture sludge

Claims (3)

In the indirect heating type drying container body, in the method of supplying the processed products including sludge and food residue, and heating them while stirring,
An indirect heating type drying method characterized in that slaked lime is added as an adhesion preventing aid to the treated product to prevent the treated product from adhering to the heated surface in the drying container. In the indirect heating type drying method according to claim 1,
The indirect heating-type drying method, wherein the slaked lime is added in a range of 10% to 100% with respect to the completely dry weight of the processed product. In the indirect heating type drying method according to claim 1 or 2,
The indirect heating is characterized in that the addition of the slaked lime to the treated product is performed before the treated product is put into the dry container body or at the same time as the treated product is put into the dry container body. Mold drying method.

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