Distillers grains are rich in nutrients and contain a variety of organic compounds, B vitamins and cellulose. They are a good edible fungus. Cultivation raw materials, as long as an appropriate amount of auxiliary materials are added to the distiller's grains, it can be suitable for the growth of a variety of edible fungi. It can not only reduce the production cost of edible fungi, but also solve the problem of environmental pollution.
1. Pretreatment of distiller's grains: Distillers grains contain alcohols, aldehydes and acidic substances that are detrimental to the growth of edible fungi, especially organic acids. There are many similar substances and must be processed before use.
You can add 1% to 3% lime powder according to the fresh weight of the fresh distiller's grains to adjust the
pH value to 8 to 11 (depending on the strain).
Cultivation of edible fungi on distiller's grains 2. Adding auxiliary materials: a certain proportion of wood chips should be added.
In addition, auxiliary materials such as nitrogen, phosphorus, and calcium should be added appropriately, and the moisture content of the materials should be controlled at 60% to 65%. The mixing ratio is: 100 kg of fresh distiller's grains, 50 kg of sawdust, 15 kg of corn heart, 20 kg of cotton husk, and 5 kg of urea.
3. Bagging and inoculation: After adjusting the materials, select a suitable polyethylene bag (depending on the strain) and use layered inoculation
< p>The seeds are spread out evenly.4. Management during the fruiting period: Since distiller's grains are rich in nutrients
and are easily contaminated by microorganisms, you should always observe whether there are any abnormalities in the strain bags
changes, and
regularly disinfect the room
. (Zhao Chun Haibin Prefecture Vocational College Postcode: 256624) Distillery grains are rich in crude protein and crude fat, and have high heat energy. The crude protein content is 54% higher than that of corn, and the crude fat content is 38% higher than that of corn. In addition, due to the large-scale reproduction and accumulation of microorganisms during the fermentation of koji, the composition and types of aminocephalic acid in the protein are relatively balanced and basically full-priced. The mineral content in distiller's grains is also very rich, and the content of major trace elements such as calcium and iron is more than 10 times higher than that of wheat and corn.
It is now common in rural areas to use distiller's grains directly as feed to feed livestock, in which a large amount of protein has not been converted
and is difficult to be absorbed and utilized, resulting in a lot of waste. Using distiller's grains to make compound feed is an economical and effective way to increase potency and make it better digested and absorbed. Different compound feeds can be made by adding additives such as trace elements according to different feeding standards for livestock and poultry
Use distiller's grains to make refined feed. It is first sun-dried or oven-dried, then pulverized, and then sent to a roller
and sieved to remove coarse matter. During the sifting process, water is sprayed continuously for rinsing, and the items under the sieve are sent to the steamer. .2 one. between .8. If it is reused for fermentation and winemaking, the effect is very good. Each ton of fresh distiller's grains requires a processing fee of about 5 yuan
.
The lees can also be used to make balsamic vinegar. Store the distiller's grains in airtight storage for 1 to 3 years10. Add water 20 per kilogram. -
400 kg, let it ferment, 2 to 3 days in summer, 5 to 6 days in winter to reach fermentation climax, 7 to 10 days
After fermentation, press to extract juice. Then according to a certain proportion of formula, 25% of distiller's grains, 25% of hot distillers' grain juice (6oC), and 5% of vinegar seed liquid. % mixed and fermented at a constant temperature of 30°C for 30 days. Skim off the bacterial film and store it for 3 to 6 months, then filter to get the balsamic vinegar. Based on an annual output of 30 tons of pure vinegar, 3.8 tons of grain can be saved.
Distillers grains can also be used to produce sodium acetate. Soak the distiller's grains in cold water, then filter the leachate, remove the suspended matter, and add alkali (NaOH) to adjust the pH to about 7. It is further heated and concentrated, decolorized with activated carbon, filtered for the second time and put into a ceramic tile pool for crystallization for 24 hours. The crystals are then dehydrated and dried to obtain the sodium acetate product. (Yang Baoai)
Using distiller's grains to produce high-protein feed
Li Dongshan and Lu Shulan, Xi'an Light Industry Machinery Design Institute, Ministry of Light Industry
1. Production of alcohol waste grains
The significance of high-protein feed
In my country's food industry, alcohol, starch sugar, monosodium glutamate, lemon acid and other industries mainly use grain as raw materials. In 1988, grain use About
5 million tons, but the utilization rate of raw materials is low. At least 30 to 40%
of the raw materials become wastewater and waste residue. In 1988, my country produced 1.08 million tons of alcohol
and emitted 1.5 million tons of alcohol. Thousands of tons of high-concentration waste liquid,
Corn only consumes starch in the process of making alcohol, and protein
is wasted in vain. The dry matter content in the distiller's grain waste liquid reaches 5 to < /p>
8%, the total amount of residual organic matter in 1 ton of alcohol distillation waste liquid is more than 500kg. The annual waste is considerable.
The biological oxygen demand (BOD) of the waste liquid discharged from alcohol production is high
up to 20,000 to 30,000p.p.M (the national emission standard is
60P.P.M) , the chemical oxygen demand (COD) is as high as 40,000 -
s000oP.P.M (the national emission standard is 10oP.P.M), which causes very serious environmental pollution.
Industrial developed countries in the world attach great importance to this and adopt
different ways to treat alcohol waste residue and control the environment
The most successful method of thoroughly polluting The distiller's grains waste liquid is made into high-protein feed by the complete drying method. It is called DDGS abroad. The protein content is as high as 27~30%. It is a project to turn waste into treasure. To produce 1 ton of wine
Jingke can co-produce 1 ton of high-protein feed. The cost is 500-600
yuan/ton, the selling price is 900 yuan/ton, and the annual output is 1.5 A 10,000-ton semen spraying plant can make a profit of 4.5 to 6 million yuan a year. The discharged waste liquid
has a BOD of 34P.P.M after treatment, and can be fully recycled.
Our country has a large population. To improve people's lives, we must vigorously develop the breeding industry. The State Council plans to produce 50 million tons of compound feed in 1990. 6 million tons of protein are needed. However, in my country's current situation, cereal cakes can provide up to half of it, and 3 million tons of protein are still needed. (7 million tons of cakes and meals). For this reason Importing fish bones
consumes about US$200 million in foreign exchange every year.
It can be seen that the use of alcohol waste residue to produce high-protein feed
not only allows the factory to turn waste into treasure and increase economic benefits, but also contributes to
environment management. pollution, alleviating the shortage of compound feed in our country, and developing
the breeding industry are all of great significance.
2. Overview of comprehensive utilization of distillers grains at home and abroad
With increasingly stringent environmental protection requirements and rising corn prices
The economic benefits of ethanol plants have declined. The treatment of alcohol residue is receiving more and more attention. The main applications are as follows: 1. Use waste residue to cultivate feed yeast. The main process flow
is that the distiller's grain waste liquid is separated into filter residue and
filtrate through centrifugation or sedimentation. The filter residue is directly dried into feed, and the filtrate is used to cultivate fermentation
Each cubic meter of alcohol waste liquid can produce 12~15kg of yeast. Its protein content reaches 40-45%. The most suitable culture temperature is 35℃. Production One kilogram of yeast needs to pass 10m3 of air,'
The BOD removal rate is 40%, and the COD removal rate is 50%. The Soviet Union and some Eastern European countries often use this method to treat distiller's grain waste. Domestic plants such as Xuzhou Alcohol General Factory also use potato raw materials to produce alcohol
Actively carry out experimental work. The key to the technology lies in the screening
of yeast. This yeast consumes the accumulated substances in the waste liquid and cannot metabolize itself to avoid adverse effects on various processes of alcohol fermentation
p>
Influence, the strains used in China are Candida SH-1 and 2
, with a small amount of urea (0.06-0.1%) and phosphoric acid (0.
02%). The existing problem is that pollution control is not thorough and consumes a lot of electricity and gas.
2. Ferment the waste residue liquid to produce biogas
After separation of the distiller's grains, put the waste liquid into a large biogas tower
After 10 to 12 days fermentation, thereby producing biogas. This method is widely used in Japan and India. Domestic Nanyang Alcohol Factory, Penglai Winery in Shandong Province and Longkou Winery in Shandong Province are using alcohol residues to produce biogas.
Using distiller’s grains to produce high-protein feed—Li Dongshan and Lu Shulan
have made achievements, and practice has proved that IM3 distiller’s grains can be produced
22M "biogas, B〔)D removed The efficiency reaches 90%, and the COD removal rate reaches 86%. The disadvantages are that the fermentation tank occupies a large area, the fermentation cycle is long, and the activated sludge must be biologically filtered. Treatment, otherwise
still cannot meet emission standards
Biogas is not only a fuel and power raw material, but also an important chemical raw material, such as methane. Chlorination can produce carbon monochloride, carbon dichloride, carbon trichloride and tetrachloromethane, etc.
3. Use alcohol waste liquid to produce high-protein feed.
Using alcohol residue waste to produce high-protein feed began in the world
in the mid-1960s, and it was basically not until 1975
that it gradually Perfect it.
Its process is to separate the distiller's grains into filter residue and filtrate through a tilt centrifuge. The filtrate is precipitated and part of it is returned to alcohol production as cooking raw material.
Most of the dilution water enters the evaporation equipment for evaporation and concentration
into a cold-dry substance, and the 40-45% thick slurry enters the dryer together with the filter residue
for drying. Finally, it becomes a product containing more than 90% of dry matter, and then it is made into pellet feed, with a high protein content of more than 27%. At present, it is widely used in the United States and Western Europe. There is no complete set of processing equipment in our country. Beijing Alcohol Factory imported DDGS equipment with an annual output of 40,000 tons from Norway. Anhui< /p>
The special grade alcohol plant has introduced a complete set of equipment from France with an annual output of 15,000 tons of DDGS
.
3. Introduction to the complete set of DDGS equipment
After simple screening and extrusion treatment, the grain distillers grains are dried to obtain dry distillers grains.
, called DDG; the dried distiller's grains obtained by evaporating, concentrating, and drying the separated filtrate is called DDs, and the feed obtained by mixing DDG and DDs is< /p>
The material is called DDGS. It can be seen from the above process that using distiller's grains to produce DDGS high-protein feed is a physical treatment process.
1. Separation equipment
Its function is to separate the insoluble solids (T.S) in the distiller's grains,
including suspended solids and soluble solids.
The separated insoluble solids (slag) are directly sent to the dryer for drying.
The soluble solids (filtrate) are sent to evaporation and concentration.
The quality of separation directly affects the success or failure of alcohol evaporation and drying
. If the suspended solids (5.5) entering the evaporator is too high, evaporation will occur. The dryer will scale quickly, and the energy consumption of the dryer will rise sharply. The waste liquor of alcohol grains is a kind of suspension containing high dissolved components and high viscosity. In addition, the ethanol factory in my country aims to make cooking
even and ensure high starch output. The wine rate generally adopts fine powder
crushing, high-temperature cooking, liquid koji saccharification process, and the saccharification koji itself
The content of a-powder enzyme is low, so the viscosity of the liquid is high, resulting in Separation
is relatively difficult. The separation equipment currently used is mainly a horizontal fine
spiral discharge sedimentation centrifuge, which was developed in the 1950s
The high-speed and high-efficiency separator is characterized by compact structure, small floor space, no filter cloth, easy operation, and continuous production.
1) Working principle of horizontal spiral discharge and sedimentation centrifuge
Figure 1 is its schematic diagram, which is mainly composed of rotating drum and spiral pusher
It consists of feeder, differential and machine base. There is an ejector inside the centrifuge drum. Both of them rotate in the same direction. However, due to the differential motion of the differential
, the speed of the screw ejector is reduced. It is 1 to 3% (8 to 10 rpm) slower (or faster) than the drum's rotation speed. The distiller's grains to be separated enter the machine through the central feed pipe. , the centrifugal force of rotation
throws it to the inner wall of the drum. Since the solid particles in the suspension
are heavier than the liquid, they are settled on the inner wall of the drum. The separated wet slag is sent to the slag outlet at the small end of the drum by a screw pusher, and is discharged by centrifugal force. The remaining water forms an inner ring and circulates in the drum. The inside of the drum
flows out through the overflow hole on the big end.
2) Selection of the main parameters of the separator
a. Separation factor: the centrifugal force experienced by the material in the centrifugal force field
and the gravity it bears The ratio is called the separation factor.
F, Yiwangdanzhulan, 1.12 fire 10-3Rn,
mg
where R is the maximum radius within the number of revolutions, n is the number of revolutions of the drum
Speed means that the diameter of the drum is large, the rotation speed is high, and the separation effect is good. But after the separation factor reaches a certain value, the prominent contradiction is the vibration of the machine and the life of the equipment. At present, the separation is more advanced at home and abroad.
The machine separation factor is as high as 2500.
b. The length-to-diameter ratio of the drum of the separator
Due to the large flow rate entering the machine and the high speed of the fluid in the machine, the corn distillers grains particles It is also relatively small. After being washed by a strong flow rate
, it will still be entrained in the separation liquid and discharged together with the separation liquid. This will reduce the solids recovery rate of the separator. For this purpose, use For alcohol
the length-to-diameter ratio of the separators is relatively large, and the short drum separator is obviously
57
Packaging and Food Machinery 1993 Volume n Phase 1
The effect is very poor, and some cannot even be separated. According to the existing data
the length-to-diameter ratios of the separators used in Britain, France and Japan are all below 1:3.5.
Feeding
Separating liquid residue
Figure 1 Structural principle of horizontal spiral discharge centrifuge
1-Differential pulley 2-differential 3-casing
5-spiral 8-main pulley
c. Differential: the speed of the drum and the screw pusher
It mainly depends on the amount of slag discharged. For alcohol grains
the particles are small, the concentration is low, and the viscosity is high, so a lower differential speed (8 -10r/min), which can make the equipment achieve better sedimentation effect and fully reduce the solid content in the separation liquid and the moisture content in the sediment. However, if the The low differential speed of the pushing screw produces a large torque resistance, which can easily damage the differential and even cause the drum to become clogged, making the machine unable to operate normally, so it is ideal. The separator adopts a stepless speed differential, which can adjust the differential speed according to the conditions of use. Figure 2 is a schematic diagram of one of the structural principles.
One way to achieve differential speed is to use planetary gear transmission, and the other
is planetary cycloid pinwheel transmission. The former is easy to process, but it produces noise when used
Large, the latter is more difficult to process and makes less noise when used.
d. In the alcohol waste liquid separation operation, uniform and stable feeding
is the main and necessary condition. For this purpose, a servo motor can be used
The screw pump, through automatic control, changes the feeding speed as the pressure in the infusion tube changes. In addition, a quantitative pump
can also be used to supply materials, but the feeding speed requires that the opening size of the relief valve be automatically changed with changes in pressure to achieve the required supply. You can also
use a frequency converter to change the speed of the quantitative pump to ensure the supply of materials
58
7-feed pipe
Uniform and stable.
4 drums per drum
8 machine bases
Due to the large processing capacity of alcohol grains, one ton of alcohol produced
12 to 15 tons of waste liquid need to be processed, so the screw pusher must be made of highly wear-resistant materials. Large centrifuges in countries such as the UK and the United States still have taper parts. Carbide embedded. In addition, if a gravity screen is used for sand removal pretreatment before entering the separator, the life of the separator screw feeder will be greatly extended.
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e. The quality of the dilute liquid after separation directly affects the quality of the concentrated liquid in the evaporator. Foreign practice has proved that the lower the suspended solids content in the clear liquid, the higher the total solid content in the thick slurry, which means that the evaporator can achieve higher heat transfer coefficient, greatly improving the evaporation capacity
This can reduce the load of the dryer and save the drying of distiller's grains
Using distillers' grains to produce high-protein feed - Li Dongshan, Lu Shulan
energy consumption.
Table 1 The relationship between the S-S of the dilute liquor gun clear liquid and the evaporator thick paddle T·S
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After rapid gasification, the steam rises at a high speed in the tube, and the material liquid is driven by the rising steam to form a film along the tube wall. It rises rapidly and continues to
evaporate to generate steam, which then heats the next feed liquid. As shown on the left side of Figure 4. The right side of Figure 4 shows the form of evaporation heat transfer and evaporation band transfer
where D·S is the soluble solids
contained in the clear liquid after separation.
S·S is the suspended solids contained in the clear liquid after separation
T·S is the total solids in the slurry after evaporation.
Sensible heat zone
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Thermal fraction coefficient relationship. Figure 5 is the boiling liquid in the rising film evaporator
Stacked
1 - shell 2 - top cover
3 - tube bundle 4 - flower plate 5.6 - nozzle .
2. Evaporation equipment
In the production of high-protein feed from distillers grains, the investment in evaporation equipment
accounts for almost one-third of the entire equipment investment. Equipment
The main parts are:
1), evaporator
Due to its high viscosity, the distiller’s grain waste liquid is easy to scale, so it evaporates
< p>Forced circulation rising film evaporators are commonly used in concentration, as shown in Figure 3.
The feed liquid enters the heating tube from the bottom of the evaporator and boils when heated
109△t
Figure 5
Heat transfer coefficients vs. Regarding the changes in temperature difference Δt, section AB is dominated by forced convection heat transfer, while section BC is dominated by nucleate boiling. Both figures
Both figures illustrate that the nucleate boiling and forced convection heat transfer systems
have the largest number, and the energy consumption is the least under these conditions, so in the design
< p> Try to meet this condition when operating. Generally, the ideal inlet temperature of the feed liquid is 2°C lower than the boiling point, so that it can reach boiling point when entering the heating tube. 59Packaging and Food Machinery 1993 No. n Volume No. 1
The steaming state should be maintained. At the same time, a certain rising steam speed should be maintained to pull the material
liquid into a film shape. If the operation is improper, local drying may occur
< p> wall phenomenon will reduce the heat transfer effect.2) Vapor-liquid separator: It is the main auxiliary equipment for evaporation.
When the secondary steam escapes from the boiling liquid, it contains a large amount of vapor.
< p>For droplets of different sizes, due to the expansion of the cross-sectional area of the gas channel in the evaporation chamber, the steam speed decreases. Some droplets settle by gravityforce, but they leave The steam in the evaporation chamber still carries a considerable amount of liquid foam. If it is not separated and recycled, it will cause entrainment loss, contaminate the condensate, and even block the pipeline.
There are many types of separators, as shown in Figure 6. The requirements for the separator
are mainly good separation effect, small steam pressure drop and low equipment
cost. Since the particles of alcohol residue are small, the liquid droplets formed during evaporation are also small, so the effect of using ordinary separators is not good, and the use of electric foam traps is too expensive. , so a steel mesh separator is used. It is rolled into a disc of the required size with a steel mesh tied to a hose, as shown in (c) in Figure 6. on top of the separation tank.
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Figure 6
3), condenser: the secondary steam coming out of the final evaporator
should be condensed. Condensers are divided into direct condensation and indirect condensation. For the production of DDGS, since the secondary steam condensate still contains a relatively high concentration of organic matter, indirect condensation is often used. , so that wastewater can be treated separately to meet discharge standards. Figure 7 is the final steam condensation process flow diagram of the separator, using two stages of condensation. The remaining gas
is taken away by the vacuum pump so that the entire evaporation system can form negative pressure evaporation
In DDGS production, the filtrate uses multi-effect negative pressure evaporation
It is very effective in saving energy consumption, and its energy consumption is only one-sixth of that of single-effect atmospheric pressure evaporation.
…………………………
---
............. ....
Production, production, production
Illustration of the final steam condensation
4). In order to increase the intensity of the secondary steam, in the 1970s Initially developed the use of centrifugal compressors as vapor recompression
Using distiller's grains to produce high-protein feed - Li Dongshan, Lu Shulan
DLK Jade S evaporation process, there are two main ones abroad. There are two forms: one is to use a steam turbine to drive the compressor, and the other is to use an electric motor to drive the compressor. The advantage is to save steam, and a comprehensive analysis can save money
< p>About energy. However, using a steam turbine to drive requires a special boiler to supply steam.And using an electric motor to drive is not reasonable except being close to a hydropower station
due to the shortage of electricity in our country. Of course, The long-term development perspective is one direction.
5). The dilute distiller’s grains entering the evaporation equipment is an important factor in the load and energy consumption of the new evaporation equipment. The recycling rate can reach
More than 40%, it can not only save process water, but also effectively reduce energy consumption, infrastructure investment and production and operation costs. For this reason, a large storage tank is often set up before evaporation, and the filtrate is used to precipitate and be reused later.
Because the dilute distiller’s grain liquid contains. .7~1% suspended matter, low cellulose content and small particle size, so it is easy to form. However, the granulation hardness is often low, so the amount of water added is average. Less,
Protein has thermoplasticity and cohesion, so its temperature is heated to a certain temperature by
steam, which is beneficial to granulation.
6) Influence of operating conditions on granulation
①The granulator requires uniform feeding to ensure the stable operation of the granulator
, and when the pellet press just starts running, the feed amount should be smaller, otherwise it will cause pressure roller slippage and material blocking accidents.
② Adding steam during granulation can moisten and heat the material
conditioning, which is beneficial to increasing output and extending the die and pressure roller
Long service life and save power.
③ Generally, the mold is used to press products with small particle size (below 5mm) at high speed, and the mold with large particle size is pressed at lower speed. Before the new die is put into normal production, it should be tested with drum skin
or rice bran oiling material to polish the surface of the die hole
surface, and can eliminate the difference in finish between each die hole.
④ Before stopping the machine, it is best to add more oil to press the material
into the hole to facilitate the next start.
⑤The temperature during granulation is as high as 85°C or above, and the temperature is also
higher, so the water content must be reduced after granulation, and its content is 7-7
12%. The evaporator will become seriously scaled after running for a period of time, so it needs to be shut down for cleaning after a period of time. Scale is caused by protein precipitation and sludge that accumulates in the heating tube, so it is usually necessary to use 1-1 3% caustic soda solution is heated to 90~95℃ for flushing.
If there is too much foam in the pipe, it will affect the evaporation efficiency.
So sometimes a defoaming agent is added to eliminate the foam depending on the situation.
3. Drying equipment
1), the physical process of drying materials
Figure 8 shows the moisture conductivity coefficient of the material and its humidity u
The relationship between p>
. The AB segment is the strongest single-molecule adsorption zone. It strongly binds moisture, and steam diffusion occurs in this segment. The BC segment is a multi-molecule adsorption zone that combines moisture. In this section, the movement of moisture
is basically in the form of vapor. Section CD
is capillary moisture, in which vapor and liquid move simultaneously.
Section DE is permeation combined moisture, which moves completely in liquid form.
Most of the dried DDGS is a colloidal object, which conducts during drying
Mainly manifests as adsorption-bound moisture and infiltration-bound structural moisture
. The drying speed is shown in Figure 9. At the beginning, the AB
section is just preheating; BC is the constant speed drying section; the CD drying speed slowly tends to be slow.
Adsorption knot
Combined moisture content
B
Tube moisture separation ~ one up
Combined moisture content Moisture permeable and infiltrated
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Figure 9
2), drying equipment in DDGS production
The drying of distiller’s grains currently mainly uses tubular dryers and
61
Packaging and Food Machinery 1993 Volume n Issue 1
Disc dryer.
a. Tube dryer
Figure 10 is the schematic diagram of the tube dryer. The steam flows through the shaft
Figure 10
< The p> end enters each tube to heat the tubes, and the material is turned from the copy plate to theupper part, and falls downward by the weight of the material itself, and is heated through the tube bundle. At the same time, There are a certain number of scraping boards arranged at a certain angle, so the material can be pushed forward. Its advantages are large processing capacity and low cost. The disadvantage is that in order to prevent the product from agglomerating, the moisture content of the feed must be controlled below 25%. To this end, a large amount of dried finished products must be returned to the dryer, causing transportation problems. The supporting equipment is large and complex, and operation
must be well controlled, otherwise the material may stick to the tubes and reduce
heat exchange, and even the nutrients of the product may be destroyed by heat. When once
the material sticks to the tube and agglomerates, it can be dissolved by high-pressure steam.
b. Disc dryer
It is a dryer developed in the 1970s. As shown in the figure
11, the turntable consists of many vertically mounted double It is composed of layers of discs and has a certain angle like a
spiral. Steam enters from the shaft into each turntable
to heat the turntable. Because the rotating turntable is immersed in the drying process
p>
in the material, thereby drying the material. During operation, the turntable rotates at a low speed of 6~
8r/min to heat the object evenly. The steam pressure is 0.5
~0.6Pa. The steam consumption for evaporating 1kg of water is about 1.1 to 1.3kg. .
The disadvantages are high cost and uneven copying.
Feeding waste gas
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c. The outlet pipe of the cyclone separator is installed along the tangent of the cylindrical part of the cyclone separator. Therefore, no matter whether a tube dryer or a rotary disk type gas is used, the air flow along the circle is obtained. The inner wall of the cylinder rotates and moves along the spiral line
Drying machine, the water vapor in the drying chamber must be eliminated in time, but the direction flows to the top of the cone, when the air flow is by the top of the separator
Since the particles of alcohol grains are very fine, they are often blocked by the cover as the steam is discharged, and the airflow rises from the center. Obviously, the cross section of the separator removes part of the product, which causes waste and pollutes the environment. , the static pressure distributed on it will be different, smaller in the center and larger along the wall.
There is a cyclone separator as shown in Figure 12, and the DDGS powder separated by the gas enters the cyclone, trying to maintain < /p>
The airflow containing DDGS powder passes through the initial direction of movement at a speed of Vm/s, and therefore moves toward the wall of the device along the radiation direction and enters the cylinder of the cyclone separator through the inlet pipe. Partially, due to entering the cone part, due to this movement, the powder is concentrated on the inner wall of the cyclone separation device, relying on gravity
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Figure 12 Principle of Cyclone Separator
Whether the cyclone separation operation is normal determines whether the cyclone separation can be carried out in a timely manner
The captured dust is discharged from the dust collector. If air leaks at a certain point in the dust exhaust system, the degree of gas purification will suddenly deteriorate. When air is sucked into the system, the air will be The air movement is opposite to the direction of dust settling, so part of the trapped dust will be carried into the exhaust pipe by the central vortex, causing loss and pollution.
4. Granulation equipment: After drying, DDGS is in the form of powder
and can be sold directly in bags. However, in order to eliminate dust and reduce
losses, the unit The weight of the volume reduces transportation and storage costs and improves digestibility. It is often pressed into cylindrical or spherical particles through a granulator
(1). The main granulators used in DDGS production are
ring-die granulators and flat-die granulators.
Figure 13 shows the ring-die granulator and its working process. The powdered feed
is fed into the mixing mechanism ②
through the continuously variable speed feeder ①, mixed with steam (or water, additives, grease, etc.) and stirred< /p>
Mix, and the mixed materials are distributed through the distributor to the rotating ring
on the working surface ③ of the pressing mold and the pressing roller, as shown in the position ① of Figure 14,
With the help of gravity, centrifugal force and mechanical guides, the powder is dispersed
The pressure generated by the rotation of the die and the pressure roller forces the powdered feed through the die orifice, and press the feed into round bars
like extrusion, and finally cut into particles of suitable length
by the cutter ③ installed outside the ring die.
Figure 14
Figure 15 is a flat die pellet press, which is mainly suitable for pressing materials with small bulk density
or high fiber content.
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The feeding and mixing of the flat-die granulator are the same as those of the ring-die granulator.
The forming principle is also similar to the ring-die granulator. , because the flat die can be seen
as a ring die with infinite diameter. As a flat-die pellet press, the
advantages are simple structure, convenient mold processing, and easy adjustment. It is more beneficial to
the production of heat-sensitive feed, but the material is on the die
It is difficult to distribute evenly, which often results in die wear
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Packaging and Food Machinery 1993 Volume 11 Issue 1
No Uniformity has shortcomings such as uneven product quality and vibration of the machine body, so the requirements for the uniformity device are relatively high. In order to reduce vibration, the mold holes of the flat mold are generally arranged in a spiral form as shown in Figure 16.
The pellets fall by their own weight, and the air passing through the pellet feed is removed by a
centrifugal fan to achieve the purpose of cooling. In order to solve
the discharged dust, dust collectors are provided.
5. Packaging equipment: It is the final process of DDGS production.
The packaging materials used are sacks and nylon woven bags.
Each bag Bag weight is 50kg.
The measurement of packaging is mostly carried by a steel scale. In order to reduce the crushing of powder
dust and particles, spiral bags are often used as shown in Figure 17
The material is screwed into the bag, and the bag descends as the material is loaded.
Pulley
二二日日目里鲁:::
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Materials
Figure 16
(2) When the granulator is working, the pressure the mold bears is 1200
15ookg/em, and the linear speed is 6-sm/s , so the choice of mold material
is directly related to its service life. Foreign stamping molds mostly use stainless steel, the UK mainly uses Z-shoot 6A, and Japan mainly uses
SuS41o (equivalent to my country's ICr13), the United States is mainly Er56A,
The hardness is Ro4o-50. Some in our country use 35CrM. Some
are cast with tin-manganese steel, and Shenyang Mechanical and Electrical College developed boron bainite
ductile iron.
(3) Issues worth noting when using the granulator
There are many factors that affect the output, power consumption and product quality of the granulator. In addition to the structural parameters of the granulator, the operating conditions are also very important.
a.DIX three S feed is usually pelleted because the protein content exceeds 27%,
fat and the temperature is not higher than room temperature 5 to 8°C
It is then cooled by a cooler. In practical applications, the air flow
through the pellet feed box is used to evaporate the excess water, and the feed
feeding spiral
Figure 17
Noteworthy issues:
(1) Dust extraction equipment must be installed to reduce pollution and improve
measurement accuracy.
(2) Measurement during use must be calibrated every day.