DK161676B - PROCEDURE FOR MOVING LIQUIDS, IN PARTICULAR SUGAR PRECAUTIONS, IN VACUUM USING INFLUENCE OF INFLUENCE - Google Patents

Description

DK 161676 B

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The invention relates to a method for stirring liquids, in particular sugar precursors, as set forth in the preamble of claim 1, and this method is characterized by the characterizing part of claim 1. This enables a saving of 5 energy while increasing efficiency and better execution of the processes on which the system is used.

Less energy consumption is achieved.

10 A sugar cooker with mechanical stirring is usually equipped with an engine of 20-50 hp, which during operation of the boiler operates at 80% of its nominal performance, but which, by working calmly in the first part of the boiling, produces a significant reduction in the electrical installation cosine, while in the latter part of the boiling must be relied on the effect of the relays which monitor the intensity of the engine's life with respect to excess consumption.

During stirring with air, consumption per sugar canister can be 5-6 HP. There is a difference of 15-30 HP per year. sugar cane container in energy consumption, which is not insignificant in a sugar factory whose production is always limited and almost always sparse.

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The invention involves a small investment, the sugar-stirring container with mechanical stirring almost always having a dual winding motor so that it can operate at two different speeds depending on the consistency of the mass.

30 Apart from the higher price for this type of engine, the price reduction speed, which is necessarily space consuming and expensive due to the significant reduction ratio, comes from 1500 rpm. per minute to 40-60 rpm. per minute, which is the speed of the stirrer.

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DK 161676 B

The supply of compressed air streams is known, in particular from United States Patent Specification No. 3,505,111, but experiments have shown that the use of an impulsive supply of compressed air streams provides an improved economy. , 5

The agitator is always a workmanship made of precious metal, which must meet specific and very sharp I

conditions for the quality of the casting and for it to be removable in pieces or parts which can be introduced at the work site, it must be made with very carefully constructed mechanical components.

The transmission shaft in the interior of the sugar cooker container must be strong and of large diameter and of very good quality of the steel and divided into two or more parts which are joined by means of mechanical components which are expensive.

It must have one or more bearings in the interior of the sugar cooker which require automatic distance lubrication in addition to spraying with pressurized water to prevent the mass of the sugar cooker from entering the bearings, which would then quickly be destroyed. The pressurized water that irrigates the bed is evaporated in the sugar cooker vessel with the resulting steam consumption.

The closure or seal of the bearing carrying the shaft at the exit of the sugar cooker container and in the upper portion must have perfect tightness, which requires careful annual repair while removing the reduction exchange mechanism. This requires, in the upper portion of the sugar cooker, an expensive bracing or scaffold to install a fixed passageway over each sugar cooker with agitator allowing disassembly of the reducing mechanism and engine. Failure or failure of the seal during the campaign means uncontrolled air access, whose repair 35 puts the sugar canister out of operation for many hours.

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DK 161676 B

All these unfortunate circumstances are eliminated by the present invention.

Another benefit is the versatility.

5 In fact, mechanical stirring requires special sugary cookware containers which must have a center hole in their tubular body where the agitator can be placed, and the vapor outlet and dropper must be changed to install the drive device 10

In contrast, the stirring of the sugar cooker with air and / or with a portion of the water vapor, with little hassle and minimal investment, allows the stirring of the sugar cooker to be adapted to the most different models of the tubular body: with a swimming cylinder, without center hole, with annular space at the periphery , with flat surface or with greater or lesser inclination of the upper tubular plate, etc.

All this simply by studying the shape of the sugar cooker in each case and the insertion of the injectors for air and / or with some water vapor at the most suitable points for optimum stirring. This improves the quality of the sugar grains.

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It is well known in any sugar mill that stirring of the pulp causes a reduction in the number of crystal germs and a significant increase in the size of the single crystals.

This means a reduction in the containment of the juice between the surfaces of the crystal germs and the retention of the juice at the acute angles or sharp corners formed by the secondary crystals on the crystal germs together with the main crystal, resulting in a reduction in the content of ash in the sugar crystals obtained with the same syrup in a sugar-cane beaker with stirring or without stirring.

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DK 161676 B

The same happens with the Icumsa color of the sugar crystals. The reduction in ash is of the order of 35% and the reduction in color of 30% for the method proposed here.

i 5 In addition, stirring is avoided irrespective of its type of points with excessive saturation and thus the formation of false.

grains during the course of cooking, which improves the uniformity of the size of the grains obtained.

10 The impact of this improvement on the uniformity during spin is commented below, which increases the benefits obtained.

Also, a reduction in boiling time and steam consumption is achieved.

In fact, stirring the cooking vessels with air and / or some water vapor ensures a reduction in the cooking time of more than 25 or 30%. This effect is more pronounced in sugar canister containers for the 2nd and 3rd products, i.e., low purity, where the formation of bubbles in the lower part of the pulp activates the cooking and greatly improves the heat transfer, even at very high viscosity.

25 in the sugar cookers, it can be estimated that the steam consumption is on the order of 130% of the water evaporated in them due to the heat losses during the prolonged stay in them.

For every 1,000 tonnes of beet treated, the steam consumption in the sugar cane containers can be expressed as:

Vapor for evaporation and evaporation ...... 107,700 kg

Vapor consumed during the stay ............. 32,230 kg

Total .................................... 140,000 kg of steam

If there is a 20% reduction in the boiling time, then logically a reduction in consumption in the form of steam loss must occur in 35 - 5 -

DK 161676 B

the same ratio, which means that the reduction in steam consumption will be 8,075 kg.

To this steam saving must be added the necessary steam, in particular in the crystallization of low purity products, to evaporate the water which the cooker enters into the sugar cooker to maintain the boiling or movement in the sugar cooker, and which is not to be estimated but which it will not. be unreasonable to employ up to 700 kg 10 for every 1,000 tonnes of processed beets.

Another advantage is that greater fluidity is created in the development of the cook. If you have experience in cookers, you know that if you need to fill a cooker that has no stirring, quickly for the sake of the factory operation, it is necessary to fill it "closed," i.e. quite undiluted, from the bottom, because if you do it under dilution to give better crystals, then it happens that if you want to concentrate when the cooker is full, then the process is so slow that it is difficult to concentrate the boiled , and it is then necessary to shut down, ie depletion, a very liquid or slightly concentrated boil, thereby obtaining a low yield in crystals and a large amount of molasses.

25 Stirring, either with air or mechanically, allows the cooker to close at the right moment, thereby obtaining a large amount of crystals and a better flattened molasses.

30 From the formula of the crystal yield: „, i .-, .. · ,, ii - the purity of the mass - the purity of the juice nn% crystal yield = -100 - the purity of the juice - x 100, it is seen that by a reduction from 79.5 to 78, 5 of the purity of the juice, with the mass having a purity of 90.0, the crystal yield goes from 51.22% to 53.49%, which is an increase of 4.5% in the crystal amount.

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DK 161676 B

By keeping the boiling liquid, ie. little concentrated, the formation of new grains is avoided as the level of the sugar canister increases, which grains will later complicate centrifugation and increase the ash content and color c- of the sugar obtained. At the same time, a reduction in the volume of the precipitate is obtained. In many of the existing sugar boiling containers, the necessity of covering the tubular chamber with syrup for concentration and crystallization is forced to take a boiling precipitate that is too large, producing some sugar crystals of excessive fineness.

If there is stirring, as recommended by the invention, this precipitation can be reduced considerably; for although the syrup is not able to completely cover the tubular body, it will, however, do so with the almost constant input of a volume of supplemental air which will cause the mass to plunge on the upper tubular 2o plate, thereby avoiding local superheating and burning which would occur if there was no stirring.

Such a significant reduction in boiling time, in particular cases, allows a new mode of operation which again allows larger crystals of sugar to be obtained simply by bringing a sugar boiler container to produce crystallisation, taking a boiling precipitate from that which is convenient taken twice as much as normal, and after crystallization and clearing, half 30 of this precipitate is transferred to another container, filling both sugarcane containers at the same time, or delaying one slightly relative to the other.

It is noteworthy that this facilitates the introduction of 35 juices.

In the cooking of the first product it is normal practice, - 7 -

DK 161676 B

that when the level is high, the juice obtained in the previous boilings is added to the sugar boiling vessel, usually the one with the greatest purity or concentration, thereby succeeding in depleting the juice and reducing the proportion of crystals in the mass which becomes more fluid, facilitating its transfer to the centrifuges.

But it is also well-known that it is not always easy to achieve a quick incorporation of the juice into the rest of the mass, since two separate phases were maintained for a time. It is during this time that the small crystals, which always accompany the juice, grow. If the sugar cook container is stirred with air and / or some water vapor as according to the invention, then when the level of more liquid filling mass increases in the container, the mixture with juice is obtained and they can be obtained quite quickly. small crystals disappear. When cooking products of lower purity, at the end of the boiling, a juice of even lower purity is often added to obtain it, concentrating the boiling, while also promoting the degree of mass flow of lightness. The speed of incorporation of this juice is fundamental to obtain optimum toning.

Easy centrifugation is also achieved.

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It has already been mentioned above that any type of stirring in a sugar cookie container, by preventing points of excessive saturation, prevents the formation of false grains and crystal germs, while also increasing the proportion of single crystals in the pulp significantly, thereby increases the uniformity of the crystals.

By transferring this mass with the greatest uniformity of the crystals to the centrifuges, a pad 35 or crystal filter mass is formed whose apertures do not capture smaller crystals and the juice therefore flows more easily. This allows the amount of mass per unit to be increased. centrifuge, where - 8 -

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prematurely shortens the total spin time.

The same is true of the washings, which can be shortened without impairing the quality of the sugar obtained, thereby reducing the amount of water and thus reducing the amount of juice formed even more.

With particular reference to centrifuges of the ASEA brand, which practically performs all centrifugation of mass from the 1st product in Spain, they have one cycle per year. centrifuge of approx. 145 seconds. The reduction in this 7-second cycle, which is readily achievable while improving the uniformity of the grains according to the invention, means an increase of 5.2% of the centrifugation performance for each machine to be added to the amount of mass in each centrifuge. is bigger.

In the case of continuous centrifuges, which are widely used today for centrifugation of low-purity products, the greater uniformity of the crystals permits the attainment of greater capacity of the machine, which gives a greater flow of the mass while the product obtained is not degraded, and you do not reach the engine load limit.

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Also, a smaller consumption of water is obtained in the washing of the sugar. -

The improvement in the uniformity of the grains also results in a reduction in the washing water of the sugar grains.

When centrifuging the pulp from the 1st product, the distribution tube on the ASEA centrifuges gives a flow rate of approx. 73 liters per minute. The mere 2 second reduction in the washing times of 14-15, which is normally used, means a reduction of - 9 -

DK 161676 B

x 2 = 2.43 liters per liter. turbine cycle which, upon dissolution of the outer membrane of the crystal, will be converted to 5 1 ^ 1 "= 12.15 kg of juice of 80 Brix.

As per 1,000 tonnes of beets will usually be 800 cycles, a reduction in the juice from the first product of 800 x 12.15 kg = 9,620 kg of juice will be obtained.

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By centrifugation of intermediates (2nd product, refined intermediate, etc.), a reduction of water in the continuous centrifuges of approx. 360 liters for every 1,000 tonnes of beets, and a corresponding amount will be obtained in the centrifuges separating the final molasses. Expressing this in juice from the intermediate products and in molasses of 83 and 84 Brix respectively, you get: 'Reduction in juice from 2nd product q-py = 2.118 kg juice 20 360

Reduction in molasses from 3rd product g-p-g · = 2,250 kg molasses In this last case, this smaller amount of molasses with approximation means more than 0.1 kg sucrose less, which goes 25 in the molasses for every 100 kg treated beets.

Another advantage is the more extensive milling at the factory.

30 The substantial investment that the sugar department makes in a factory means that there are many factories with large milling and evaporation capacities which seem to need to retain a significant portion of the syrup in large depots, so that when they are grinding the beets has ended, with huge 35 energy costs converting this syrup into crystalline sugar.

DK 161676B

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The reduction in the cooking time for each sugar cooker corresponds to a corresponding expansion of the sugar compartment and thus an increase in the capacity for cutting and treating the beets, which results in a little expensive form with modest means.

Any improvement of the final product, in this case the reduction in the Icumsa color and the content of ash in the sugar in connection with the better quality of the grains makes it possible to sell easier or to sell at a better price.

To summarize the hitherto soft concerning the stirring of the sugar cookers with compressed air and / or with some water vapor, the following assessment can be made: 15 1. A medium investment is required in the installation itself, which can be expanded according to the conditions in each factory with the installation of a new vacuum pump and increase 2 ° of the collector, which feeds the uncondensable gases from the barometric column to the vacuum pumps.

2. A reduction in the energy consumed between a sugar canister with mechanical stirring and stirring with air after consumption in kW.

3. Reduction of investment of the order of 2-5 million pesetas per year. sugar canister by mechanical stirring for an investment of 0.9 - 1.3 by stirring with air and / or with some water vapor according to the characteristics of the installation to be performed.

35 4. Possibility of stirring any type of sugar cooker container where mechanical stirring is not enough.

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DK 161676 B

5. Reduction in the consumption of steam of 8,775 kg for every 1,000 tonnes of beets per day. assuming an evaporation in boilers of 12 kg of steam per day. kg of fuel, steam for heating the sugar cookers from 2.

5 evaporation power and a fuel price of 23 pesetas per kg, means a saving in pesetas per daily for every 1,000 beets of: 8,775 1 - ^ - x Ϊ2 K 23 = 8,410 pesetas per day. day.

10 6. For better depletion of the juice with 1 purity point, in the first product, the increase of crystals is estimated to 4.5%, which goes from 51.22% mass to 53.49%, ie. an increase of 2.27 kg of crystals per 100 kg mass. This logically means a reduction in juice of 2.27 / 0.785 = 2.89 kg of juice with purity 78.5%.

For every 1,000 tonnes of beets per day. today we want: 336,000 x 2.89 / 100 = 9,710 kg of juice, "as added to the 9,620 kg, which reduces the juice by less water consumption for the washing of the white sugar, yields 18,330 kg, which would be converted to mass in the 2nd product, giving approx. 17,100 kg, which again would have given us, with purities of 83.6% and 69.7% of the mass and juice respectively, 46% crystals and 54 / 0.80 = 67.5 kg of juice of the 2nd product. Converted to cut 1,000 tonnes of beets per today it would be:

Reduction of sugar crystals for gene melting 17,100 x 0.46 = 7,860.

Reduction of 2nd product juice for boiling into 3rd product 17,100 x 0,675 = 11,542.

The sugar crystals to be re-melted give dissolved in juice or water 7.860 / 0.70 = 11.228 kg of re-melted syrup which would go to the 1st product and give 8.773 kg of pulp at 35 90 ° Brix.

DK 161676B

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This means that the amount of mass of 336,000 kg for every 1,000 tonnes of beets is reduced to 327,270 kg, which is a reduction of 2.6%. The 11,542 kg of juice, which is less weighted, added to the 2,188 kg due to less water consumption 5 in the second product, will give 13,730 kg of juice which is produced less and which will give 11,828 kg mass less in the third product by concentration from 80 to 93 ° Brix.

That is, the 71,000 kg of mass in the 3rd product produced under an assumption of 71 kg per tonnes of processed beets will be reduced to 71,000 - 11,828 = 59,200 kg mass of 3rd product.

Of this mass, which is produced less, we would have obtained 15 if the purity is 73% in the mass and 58.0% in the final juice or molasses, 35.7% crystals and 64.3 / 0.84 = 76.5 molasses, i.e .:

Reduction of crystals for refining from 3rd product 11.828 x 0.357 = 4.222.

20 Reduction of molasses to the tank 11,828 x 0.765 = 9.048.

Adding 2,250 kg to this amount of molasses, which is reduced by the smaller water consumption in the centrifuges of the third product, will yield 11,298 kg for every 1,000 tonnes of beets which fail to enter the molasses tank.

These calculations seem optimistic at first glance; it has been assumed that all the water entering the centrifuge 3 ° dissolves sugar and does not dilute the juices, but does not take into account the effect of the reduction in mass production on the juices obtained in the product, with lower purity.

Only by including these do you get a general idea of the importance that the stirring of the mass boiled in sugar-boilers with air and / or with some water vapor can - 13 -

DK 161676 B

provide in the technical balance of the results at the end of a campaign, which ultimately determines the improvements and changes to be made between the campaigns.

5 In the main, the invention consists in the addition of a new experience which is unknown to date due to the apparent discrepancy which is due to the fact that one has never considered it advantageous to use one in which a vacuum is created to certain operations, injecting air 10 and / or some water vapor.

In practice, the invention is accomplished by the incorporation of appropriate mechanical elements which are programmed and subordinate to a cycle and placed in particular positions which are advantageous to the cookers, determining these incorporations in the material to be processed and by impulses of air and / or some water vapor, the elements provide the desired intensity and duration of the stirring, thereby producing a great speed in the preparation of the product.

As can be seen from the above soft, the system has great versatility as there are no limitations on the mechanical type of application which is possible in a wide variety of industrial processes and on a small scale for experimental processes.

The components used for the injection of air 30 and / or air mixed with water vapor, as well as its incorporation into the reactors in which it is used, are either commercially available or can be readily manufactured, making the system in question very attractive to use. it is also robust and has a long life.

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Claims (4)

A method of stirring liquids, especially of sugar precursors or thick juices, in vacuo, forming several stirring streams in the juice by means of distributed inflated compressed air streams, characterized in that the compressed air streams are impulse-induced in the interior of the container through a number of nozzle-like injectors. A method according to claim 1, characterized in that the stirring streams are controlled from the outside in time or temperature. Method according to claim 1 or 2, characterized in that the blown air is introduced tangentially over the bottom product in the container. Process according to claims 1-3, characterized in that a high crystallization and formation of a large bottom product is carried out in a separate, pre-boiler serving boiler, on which part, especially half of the bottom product is transferred to another separate boiler. , after which you work with both boilers at the same time or with only a slight difference in time. 25 30 35