Sweet potato vermicelli is a product of deep processing in the sweet potato series. The production process is divided into three types: one is through extrusion molding, and the sweet potato vermicelli produced by this method is generally used to produce thin vermicelli (including instant noodles). In recent years, due to people's attention, the mechanization level of its production has been continuously improving, so large noodle factories generally adopt this method to produce noodles; The second method is cloth pulp steaming, which produces sweet potato noodles with a maximum output of around 3-4 tons due to the impact of equipment cost. Another type is the "leaky ladle" style. The noodles produced by this method are widely distributed in rural areas and towns north of the Yellow River in China, and are deeply loved by local people. Although it has a long history, due to limited research and the uneven development of urban and rural areas in China, the existing "leaky ladle" sweet potato noodle production equipment is rudimentary, with low automation and poor hygiene conditions, which cannot meet the requirements of the National Food Safety and Health Law. Therefore, in order to adapt to the production of large-scale mechanized vermicelli factories and ensure that the products produced have good quality and taste, it is necessary to develop a "leaky ladle" type automated large-scale production equipment for sweet potato vermicelli to meet the needs of the market.
The production process of "leaky ladle" style sweet potato vermicelli is as follows: starch raw material → thickening → stirring → vacuum pumping → powder leakage → water boiling → cooling → cutting → hanging rod → freezing → deicing → drying → cutting → packaging → finished product. The Jianli Food Technology and Equipment Research Institute has developed a 1000 kg/h "leaky ladle" type sweet potato noodle production line for a large and well-known food processing enterprise in China. It uses patented technology to ensure that the produced sweet potato noodles not only have stronger toughness and better boiling resistance, but also maintain traditional taste. It also achieves automated production to a large extent, reducing the labor intensity of workers.
The thickening process is the key to the production of "leaky ladles" style sweet potato vermicelli. The moisture content, degree of gelatinization, and toughness of the sauce are the factors that determine the success or failure of sweet potato starch stirring. A good sauce should be crystal clear, have good toughness, and have high viscosity. Our designed thickening machine adopts automatic water addition according to the amount of thickening, automatic frequency conversion speed regulation stirring at low speed and then high speed, and automatic steam heating at regular intervals until the gelatinization is uniform, reducing errors caused by inexperienced operators. Abandoning the previous method of simply adding water and stirring it into a starch emulsion, and then adding boiling water or steam heating. Practice has proven that variable speed stirring can not only save energy, but also enable starch to be fully mixed with water, resulting in a sauce that fully meets production requirements.
The starch raw material is transported by wind power, which enables the raw materials to be continuously and evenly sent to the multi-stage double helix continuous mixer, reducing the labor intensity of workers. Due to the kneading, pinching, pushing, and pulling effects of the double helix stirring on starch, it makes starch more flexible, water absorbing, sticky, and has better boiling resistance. The feeding is more uniform, making it easy for the equipment to maintain production continuity. Therefore, this double helix mixer has gradually replaced the single box single axis paddle type mixer and has been used in sweet potato noodle production line equipment, achieving good results.
The water boiling process and equipment have gradually evolved from traditional methods of powder boiling to a new type of water boiling machine with automatic lifting of the machine cover, energy conservation, environmental protection, easy cleaning, automatic temperature control, and continuous operation. This water boiling machine adopts a curved lifting cover, which is easy to operate, safe and convenient. During production, the entire water boiling tank is in a sealed state except for the outlet. Water vapor is controlled inside the tank and can only be guided outdoors through an exhaust hood. This not only avoids the overflow of water vapor indoors and affects the indoor temperature, but also increases the heating speed, ensuring a clean and hygienic working environment. The boiling temperature is controlled by adjusting the switch of the solenoid valve to increase or decrease the amount of steam intake. At the same time, after being filtered, the steam is directly directed into the water boiling tank to add hot water, which increases the temperature quickly and saves costs. The cooling method adopts continuous and uniform water spray transportation cooling, which can quickly cool the noodles and wash off the gelatinization layer of the noodles, ensuring the appearance of the noodles and facilitating the next process.
The automatic hanging rod process of noodles adopts patented technology, hanging three hanging powders on one rod. The entire process has achieved technologies such as automatic pole feeding, automatic pole hanging, automatic pole pressing, and automatic pole feeding. The hanging rod is made of stainless steel round tube with patterns to reduce the sliding of the powder bar. The cutting blade can move up and down, allowing the cutting length of the noodles to be adjustable within a certain range, to achieve the best hanging length for different product specifications. Every time the powder is hung, a pressing action should be performed to ensure that the powder bars do not slip off during the hanging process. When a round tube is filled with vermicelli three times, the pressure rod and hanging rod move together to the designated position, and the pressure rod returns alone. The hanging rod is lifted by another conveyor chain and sent to the collection rack, and enters the cold storage through the transfer mechanism. The proximity switch can accurately control the position of the hanging rod, ensuring seamless connection throughout the entire process.
The hanging powder rod automatically runs in the cold storage for several hours. After the water droplets on the noodles form ice crystals, the hanging powder is automatically transferred to the thawing machine. The thawing machine is a box enclosed on all four sides, which completes the transportation of noodles through two chains. There are two rows of water spray ports installed on the upper and both sides of the thawing machine. The ice crystals adhered to the noodles are washed and melted by the water sprayed out inside the thawing machine, causing the noodles to naturally disperse and rarely be drawn together. Frozen noodles have strong toughness, fast drying, straight noodles, and are easy to package.
In order to strictly comply with the requirements of the national Food Safety and Health Law for the production of vermicelli, avoid the influence of weather changes, and reduce the labor intensity of workers, a large dryer is used instead of the natural drying of vermicelli. The dryer is composed of a body, an upper rod manipulator, a lower rod manipulator, a blowing system, a moisture removal system, a conveying system, a heat dissipation system, etc. The entire body is covered with insulation boards, with insulation board doors on both sides, and transparent glass doors and windows at the entrance and exit, making it easy to observe the drying and transportation of the powder bars in the room. The hair blowing system consists of multiple variable frequency speed regulating fans, while the moisture removal system consists of speed regulating fans and air ducts, which can achieve automatic temperature and humidity control and speed control.
The noodle cutting machine also adopts patented technology, which can cut the noodles according to a certain length as needed. The cut noodles have less broken powder, high yield, and are easy to pack.
The new "leaky ladle" sweet potato noodle production line adopts new electronic control technology and boldly innovates the hanging powder technology that has long troubled people. It not only improves the degree of automation, reduces the labor intensity of workers, but also increases the production of noodles. It can be anticipated that under the conditions of a larger market for such products, with the continuous exploration and research and development of deep processing technology for sweet potato vermicelli, a more intelligent and fully automated "leaky ladle" type sweet potato vermicelli production line will appear in front of people's eyes.