Canna Starch Processing Line For Canna Extract Processing

System Flow Chart

Process Description

1. Raw material receiving unit

The acquired canna is first stored in the canna storage tank. Next to the flow ditch at the bottom of the canna pond, a flushing water pipeline is pre-installed, and the base of the flushing water cannon is installed on the pipe according to a certain interval, and the flushing water cannon is installed on the base. The flushing water pipeline is connected to the sewage pump coming out of the circulating water tank, and the circulating water is pumped into the flushing water gun through the sewage pump, and the canna in the pool is flushed with the flushing water gun. Canna and water flow into the workshop through the flow channel.

Special precautions: Before flushing, large pieces of canna should be manually decomposed to facilitate flow and pumping, otherwise it is easy to block the flow ditch.

2. Hydraulic conveying unit

The main purpose of this unit is to transport the canna in the canna storage tank into the paddle washing machine by hydraulic power. During the conveying process, the canna taro is continuously rolled and rubbed in the water flow, which can peel off the soil adhering to the canna taro, which has a good cleaning effect.

When producing starch, the cover plate of the flow channel near the outlet end of the canna storage tank is lifted, and the flushing water is pumped in from the other end of the flow channel. The canna is flushed with a water gun, and the canna is evenly entered into the dehydration grid along the flow trough with the water flow. There is a gate valve at the outlet end of the pond flow tank. By adjusting the valve opening, the ratio of canna and water in the entire flow tank can be controlled, and it can be evenly transported into the workshop.

The smoothness, shape and slope of the flow trough play a crucial role in the flow of canna. The bottom of the flow trough we designed is semi-circular and the slope is reasonable, which can well transport the canna into the belt conveyor in the workshop.

3. Cleaning and crushing unit

The canna conveyed with the water flow is filtered by the dehydration grille to filter out the flushing water, and then directly enters the baffle belt conveyor.

The canna taro conveyed from the baffle belt conveyor directly enters a set of two-stage series paddle-type cleaning machines to thoroughly clean the canna taro, remove the residual sand and broken skin, and ensure that the raw materials entering the filing and grinding section are clean. In the first-stage cleaning machine, part of the process wastewater (cyclone overflow water) can be optionally added to reduce water consumption; if there is no shortage of local water resources, it is better to add clean water. The main function of the front part of the washing machine is to fully soak the raw materials, so that the canna is removed by mutual friction and stirring. The raw materials are sent to the clean water tank of the next level through the water tanks in different areas, and the clean washing water is added to the washing machine behind, so that the canna is cleaned by the counter current cleaning method. The cleaned raw materials are transported to the conveyor belt with a large inclination angle. The sand and impurities in cleaning need to be discharged regularly.

After the washed canna comes out of the paddle washing machine, it enters a drum spray washing machine. The materials are rubbed against each other in the drum, and the fresh water is sprayed on the canna under a certain pressure, which further takes away the dirty water on the surface of the canna. Finally, the clean canna is sent to the crusher on the temporary storage warehouse of canna through the sprayed belt conveyor, and the large canna is cut into small pieces by the crusher. Small pieces of canna are directly stored in the temporary storage warehouse of canna. Canna bins are generally designed to store one to two hours of volume.

4. Filing pumping unit

The filing unit is the most important link affecting the extraction rate of canna starch. The high-efficiency filing machine can completely release the starch granules in the canna cells and ensure that the content of bound starch in the residue is reduced to a minimum.

A specially designed discharge port is connected below the canna silo, and the discharge port is connected with a speed-adjustable feeding screw. The feeding screw has three outlets, two filer ports and one overflow port. There is a short circuit with a flapper valve between the filer and the feeding screw. When the system wants to feed, first open the flapper valve on the file mill, then adjust the frequency of the feeding screw as needed, and start the feeding screw to start feeding. The filed canna pulp is pumped into the desanding unit with a single rod pump.

The specially designed stainless steel filing machine is very easy to operate. The compact file clamping system ensures that the file works in the best position. The loading and unloading of the file is very simple, and it can be done by ordinary people without the use of special tools at all. The stainless steel screen is a one-piece construction and can be replaced without tools, allowing the filer to achieve maximum efficiency and starch yield. The distance between the file and the fixed block is 1~2mm to ensure higher filing efficiency. The capacity of the entire line can be adjusted by means of a speed-adjustable feeding screw.

Special instructions: In order to process canna, the filing machine we are equipped with is a heavy duty filing machine, and the filing bar is thickened with wide teeth, which is specially used for the processing of coarse fiber materials.

5. Cyclone desanding unit

The canna pulp obtained by filing is pumped into a desanding cyclone by a single-rod pump. The material with a certain pressure enters the desanding cyclone along the tangential direction. In the cyclone, the canna pulp rotates at a high speed, the light phase starch and canna residue overflow from the top, and the heavy phase sand is discharged from the bottom. There is a sand accumulating tank under the ceramic swirl tube. The sand accumulating tank is connected with pressure backwash water to ensure that the starch will not be lost from the bottom flow port, and the discharged sand particles are regularly discharged through two airbag valves.

We use specially manufactured ceramic swirl tube for durability, and the uniquely designed air bag valve can automatically and regularly discharge the sand.

6. Centrifugal extraction

Centrifugal extraction is another key unit of the entire production line that affects the yield of canna starch. A good centrifugal sieve and process can extract the free starch that is broken from the canna cells.

The extraction unit is a centrifugal sieve group consisting of three centrifugal sieves, each of which is equipped with a fiber pump and a defoaming pump. The canna pulp from the desander enters the first-stage extraction screen. Under the centrifugal force of the high-speed rotation of the screen basket, the starch passes through the screen and the slag remains on the surface of the screen basket and is thrown out. There is a certain pressure of flushing water on the front of the screen basket at all times, which is sprayed from the nozzle to make the slag roll continuously, so that the starch in the slag can be fully separated. The back of the screen basket is also designed with flushing water, but the back flushing water on the back is regularly turned on to ensure that pectin and slag do not block the screen. The starch milk is pumped to the cyclone station for washing through the defoaming pump, and the slag is pumped to the second-stage centrifugal screen through the fiber pump. The slag containing a certain amount of starch will further extract starch in the second-stage centrifugal screen, the water containing starch will enter the process water of the extraction system through the defoaming pump, and the slag will continue to be pumped to the third-stage extraction screen through the fiber pump. Similarly, the third-stage extraction screen still performs starch extraction, the undersize still enters the process water of the extraction unit, and the slag is pumped to the slag dewatering unit.

The three-stage series centrifugal sieve group can ensure that all free starch is collected into the extraction system, so that the residue does not contain free starch, which fully guarantees the extraction rate of starch. Unique process design and excellent equipment performance ensure that we can completely extract free starch from slag.

7. Slag dehydration

The slag pumped from the extraction unit is dewatered by a centrifugal screen, which works on the same principle as the extraction screen. The slag is finally transported out of the workshop via a screw conveyor, while the water from the slag still returns to the process water system of the extraction unit.

8. Concentrated and refined

Concentration refining is the most important unit of the entire production line, and the quality of starch is completely guaranteed in the cyclone refining unit. The impurities in the starch slurry are completely removed by physical methods, so that it does not affect the quality of starch products.

The starch slurry from the first-stage centrifugal screen enters the 16-stage concentrated cyclone washing unit, and the process water is pumped from the other end of the cyclone station to wash the starch in a counter current manner. The entire cyclone station can be divided into three parts. First, the starch slurry is dejuiced and concentrated through the concentrated cyclone station. The concentrated starch milk enters the 13-stage washing unit, and the cell liquid from the overflow enters the two-stage recovery cyclone. The flow station recovers the starch contained in it. Most of the waste liquid overflowing from the cyclone station containing a large amount of fiber impurities is directly discharged, and a small part still enters the process water system of the extraction unit. The starch milk from the cyclone station is pumped into a stainless steel starch milk storage tank with an agitator.

The clean process water is added from the last stage of the cyclone station, mixed with the starch milk for washing, and then the overflow is mixed with the previous stage of starch milk for washing and separation. In this way, the first-stage counter current washing makes the fibers and cell fluids discharge with the water. Swirl Station. The thirteen-level washing can ensure the washing effect of the cyclone station, better remove impurities such as fiber and protein contained in the starch milk, and ensure that there are no impurities in the starch milk coming out of the cyclone station. In this way, it can be ensured that all indicators of the produced starch meet the standards.

9. Vacuum dehydration

The water content of the starch milk coming out of the cyclone station is too large to be directly dried, so it is necessary to dehydrate the starch milk first, so that the starch water content is about 40%.

The starch milk is pumped from the starch milk temporary storage tank to the vacuum dehydrator tank with a starch pump, and a water pipe is connected to the starch milk pipeline, and the starch milk is diluted to a certain concentration with process water. The vacuum pump forms a negative pressure in the vacuum drum. When the starch emulsion is in contact with the vacuum drum, the starch slurry is sucked on the drum surface, the filtrate is sucked into the filtrate separation tank and pumped away by the filtrate pump, and the filter cake is scraped off by a scraper, and transport it into the feeding hopper of the air flow dryer with a food-grade conveyor belt.

Our vacuum dehydrator has excellent performance, simple and stable operation, and the moisture content of starch after dehydration is very low, which greatly reduces the energy consumption of subsequent air drying.

10.  Air drying

The air dryer further dries the dehydrated starch to the moisture content required for commercial starch. The air is heated to the required temperature by the heat exchanger through the filter screen, and the hot air is sucked into the dryer by the induced draft fan. The dehydrated starch is transported to the feeding screw with a hopper, and is transported to the feed port of the airflow dryer through the screw. The starch enters the cyclone separator along the air duct along with the hot air in the airflow dryer, and the dried starch enters the cyclone separator. The cyclone separator is separated from the air, and the wet air is discharged through the induced draft fan after leaving the cyclone separator. The starch enters the finished product warehouse through the air shutoff device under the cyclone separator.

11.  Screening storage

The starch is screwed into the vibrating screen through the finished product warehouse, and the vibrating screen sieves and grades the dried starch to remove the gelatinized and coarse particles in the refined starch, so that the fineness of the finished starch can meet the standard.

12.  Weighing Packaging

The sieved starch is packaged into 25kg bags.