JPS5818123B2 - Renzokuketsushiyousouchi - Google Patents

Description

[Detailed description of the invention] The present invention relates to a continuous crystallization apparatus for sugar, etc.

In the conventional batch sugar crystallization process, purified and preconcentrated mother liquor is fed into a crystallizer with an internal heating surface, concentrated to a supersaturated solution, and then seeds are fed to make it ultrahigh.
Mother liquor is sequentially replenished as the ultra-high crystals grow, and the crystals are grown to the desired size before being discharged. However, mother liquor supply, concentration, ultra-high, pre-high, and discharge are repeated. , there is a loss of time for roasting sugar, and a large amount of steam, electricity, etc. are consumed.Also, as the crystals grow after ultra-high temperature, the mother liquor is replenished one after another and the height of the liquid is raised, resulting in poor circulation of the processed material. ,
Causes uneven crystal grain size.

One possible way to alleviate these problems is to install an internal stirrer to improve circulation, but as mentioned above, sugar crystallizers can be used in a wide range of products, from low viscosity liquids to high viscosity slurries. Since both are stirred by the same stirrer, the stirring efficiency is extremely poor and the provision of a stirrer is not as effective.

In order to eliminate the drawbacks of the batch-type crystallizers mentioned above, many proposals have been made for continuous-type crystallizers. Most of them have a similar structure, and they are not satisfactory as there is not much progress seen.

In the present invention, a heating band (calandria) with heating tubes attached to the upper and lower tube plates is arranged concentrically on the outer periphery of the can body, and a downcomer pipe is arranged concentrically in the center of the can body. A large number of crystal chambers are created by radially partitioning a central cylinder placed upright in the center of the downcomer pipe with partition plates, and mother liquor is supplied to one of the crystal chambers and sequentially moved to the next chamber. The above-mentioned drawbacks have been solved by concentrating, super-concentrating, and pre-concentrating and finally completing the crystal, and the details will be explained below with reference to the drawings.

The attached drawings show an embodiment of the present invention, in which 1 shows a can body;
2 is a central cylinder, and 3 is a descending pipe (pipe body).

The can body 1 has a circular cross-sectional shape (planar shape), and the downcomer pipe 3 is provided at the center of the can body 1, and the center tube 2 is provided at the center of the downcomer pipe 3. .

A heating zone 7 in which heating tubes 6 are attached to upper and lower tube plates 4.5 is installed on the outer periphery of the can body 1.
A large number of crystal chambers a, b...
・It is divided into g.

The central cylinder 2 is provided with a supply port 10 for supplying mother liquor and ultra-high-grade seeds to each crystallization chamber, and the heating zone 7 and the can body 1 are provided with an inlet 11 for blowing steam into the can. A discharge port 12 is provided for discharging the steam evaporated within the body 1 to the outside.

Reference numerals 13 and 14 indicate weir plates for adjusting the liquid level of the mother liquor, which are provided alternately at the outer and inner ends of the partition plate, and the mother liquor is supplied to the weir plates 1
3 and 14 overflow and flow into the next crystal chamber.

Further, 15 is a stirring device installed in the downcomer pipe 3, which circulates and stirs the mother liquor through the heating pipe 6 and the downcomer pipe 3.

Reference numeral 16 indicates a discharge port for the processed material, and the arrows in FIG. 2 indicate the movement locus of the processing liquid (the solid line indicates the upper layer, and the broken line indicates the inner layer).

Note that the stirring device 15 is used to improve circulation of the processing liquid.
This is more effective in achieving a uniform front height of the crystal than circulation solely by convection caused by the action of the heating zone 7.

The center cylinder 2 facilitates attachment of the partition plates 8 and 9 to the can body 1, and also prevents the partition plates 8 and 9 from coming close to each other at an acute angle in the center of the can body 1, thereby preventing local retention of mother liquor. Improve the circulation.

In order to supply the mother liquor to the crystallization chamber, it is advantageous to discharge the mother liquor from the supply port 10 into the downcomer pipe 3 and diffuse it sufficiently, and then to raise the heating pipe '6.

The heating zone 7 can be shared by all or some of the crystal chambers, or can be provided individually in each crystal chamber.

゛Also, the crystal device shown in the figure is of the Calandria type,
The present invention can also be applied to other types of crystal devices such as ring element type and coil type.

゛The continuous crystallization device of the present invention has the above structure, and the mother liquor is introduced into the first crystallization chamber from the supply port 10, and the weir plates 13 and 14
The mother liquor is allowed to overflow and sent to the next crystallization chamber in sequence, and the mother liquor is concentrated by supplying the starting material and the heating zone 7, etc.
It is possible to gradually crystallize from the front height, complete the crystal in the final crystallization chamber, and take it out continuously from the discharge port 16, and has the following advantages.

(a) Crystallization is carried out in multiple crystallization chambers, and the level of the operating liquid can be set as low as desired, which not only reduces the boiling point rise temperature due to liquid head pressure, but also reduces coloring of the processing liquid. The low surface improves the circulation of processed materials.

(b) In the conventional apparatus, the entire amount of the processing liquid is stirred with a stirrer, but in the present apparatus, only the necessary crystallization chamber can be stirred, so power consumption and equipment costs are reduced.

- (c) When changing the type of processing liquid, it is necessary to match the residence time to match the physical properties of the processing liquid, but in this device, this can be easily adjusted using the movable partition plate 9, making it highly versatile. rich in

(d) A conventional batch-type crystallization apparatus can be used as a continuous crystallization apparatus by slightly modifying it.

(e) Since the weir plates 13 and 14 are provided alternately at the outer and inner ends of the partition plates 8 and 9, the mother liquor can be made to flow efficiently and smoothly without stagnation.

(f) Since the central cylinder 2 is provided in the center of the can body 1, it prevents the fixed partition plate 8 and the movable partition plate 9 from coming close to each other at an acute angle, prevents local retention of mother liquor, and The partition plates 8 and 9 can be easily attached.

(g) The center cylinder 2 is provided with a mother liquor supply port 10, a draft product supply port, etc. to organize the entire body in an attractive manner, and the mother liquor and ultra-high-grade species are gradually fed from the center of the can body 1 toward the outer periphery. It is possible to promote crystallization by flowing the liquid so as to diffuse it.

As explained above, according to the present invention, it is possible to provide an excellent continuous crystallization device that has good crystallization performance, is simple in structure, and has low operating costs.

Brief description of the drawings □ Figure 1 is a longitudinal cross-sectional view of the present continuous crystallization device, and Figure 2 is a cross-sectional view.

1... Can body, 3... Downcomer pipe, 7...
... Heating zone, 10 ... Supply port, a 'y b
+ C+ d s e p ft g...Crystal chamber.

Claims (1)

[Claims] 1 Has a central tube 2 in the center? Outer surface and the above center cylinder 2
A can body 1 in which a steam discharge port 12, a crystal discharge port 16, and a mother liquor supply port 10 are formed; a tube body 3 disposed concentrically around the central tube 2 in the can body 1; heating zone 7;
A fixed partition plate 8 and a movable partition plate 9 are arranged radially within the can body 1 around the central tube 2 and partition the inside of the can body 1 into a plurality of crystal chambers a'' and 9; and the partition plates 8, 9. Weir plates 13 and 14 for liquid level adjustment, which are provided alternately at the outer and inner ends of the crystal chambers 13 and 14 to allow the mother liquor to overflow into the next crystal chamber, and the crystal chambers a"'-g.
A continuous crystallization apparatus characterized by comprising a stirring device 15 that circulates the mother liquor in the crystallizer through a heating tube 6 and a tube body 3 constituting a heating zone 7.