What are the new types of rice milling machine

With the continuous improvement of living standards, people have higher requirements for the quality of rice. The traditional rice milling machine will increase the rate of broken rice due to backward technology. Therefore, in order to reduce the rate of broken rice and improve the quality of rice, it is necessary to use multi-machine light grinding process. However, the cost of multi-machine light grinding process is high, and the new rice milling machine is born. What are the types of new rice milling machine? Let's understand the type and principle of the new rice milling machine.

What are the types of new rice mills in 1.?

At present, there are many kinds of rice milling machines used in the domestic rice processing industry, and the main working part of the rice milling machine is the roller. According to the type of roller, it can be divided into sand roller rice milling machine and iron roller rice milling machine. According to the form of roller device, it is divided into vertical rice milling machine and horizontal rice milling machine. According to whether it is sprayed with air or wet, it is divided into sprayed-air rice milling machine and humidified rice milling machine.

1. Sand roller rice mill

The rice mill made of carborundum roller is called sand roller rice mill. The white grinding process of the sand roller rice mill is as follows: brown rice is in the white grinding chamber, and the skin of rice grains is removed by means of the sharp edge of hard and sharp dense carborundum grains moving at high speed. The effect of grinding white is determined by the following two factors:
First, there is a certain grinding force, enough to destroy the structure of rice skin; Second, the grinding opportunities provided are numerous and uniform. For this reason, the emery roller should have a large line speed, and at the same time, the rice grains should have enough opportunities to roll.
The sand roller rice machine is divided into vertical and horizontal. According to foreign data, the pressure in the vertical sand roller rice machine is relatively small, and the rice grains are basically in a suspended state in the white grinding chamber. The white grinding function is completed by light grinding of the rice by the rotating sand roller, thus the damage to the rice in the white grinding process is relatively small, the vertical sand roller rice mill is suitable for milling varieties with poor grain strength, crisp structure and dry and hard surface.

2. Iron roller rice mill

The rice mill with iron roller is an iron roller rice mill. The rice milling process of the iron roller rice mill is as follows: in the rice mill, the brown rice produces friction through the relative movement between the rice grains and the rice mill components and between the rice grains and the rice grains, and its effect goes deep into the rice grain cortex, causing the rice grains to slide relatively along the surface of the endosperm, and be stretched, broken until they are separated from the endosperm.
The pressure in the rice milling machine is relatively large, and the local pressure often exceeds the compressive strength of the rice grains. In the process of rice milling, broken rice is easily generated, and the power consumption is large. The iron roller rice mill is suitable for processing japonica rice with high structural strength.

3. Vertical rice mill

The main shaft vertical rice mill is called vertical rice mill. The advantages and disadvantages of vertical rice milling machine are:

Advantages:

(1) Gravity has no effect on the centrifugal acceleration of rice grains, the speed of rice grains is uniform, and the pressure in the white grinding chamber is uniform. When feeding, gravity generates driving force on the whole length of the white grinding chamber, and the meter flow is more uniform.

(2) The number of rice knives is large, the material is soft, the adjustment is convenient, the rice grains roll well, and the damage to the rice grains is small. The grinding white roller is made of grinding wheels in series, and the grinding time can be partially replaced or adjusted for use, thus improving the service life of the sand roller. The bran layer is discharged smoothly. Low rate of broken rice.

Disadvantages:

(1) High requirements for maintaining smooth operation. During the manufacture and installation of the rice mill, the axis of the white roller must be kept vertical with a slight error. Even if the white roller is completely balanced, the center of gravity will deviate from the plumb line to generate unbalanced force.

(2) The bearing is subjected to a two-way force combined in the axial and radial directions, which requires high performance, manufacturing and assembly of the bearing.

(3) The volume and weight of the unit output are large. The use of gravity as axial driving force is limited, and the axial velocity of the rice flow is small. Under the condition of the same feed material as the horizontal rice mill, the diameter of the white roller must be increased to increase the annular cross-sectional area of the white chamber, and the volume and weight of the rice mill increase with the increase.

(4) It is inconvenient to disassemble and assemble the sand roller, which is time-consuming and laborious.

(5) soft rice knife wear faster, more quantity, maintenance costs increased.

(6) It is difficult to combine two white rollers coaxially or in different axes on a rice mill.

4. Horizontal rice milling machine

A rice mill with a horizontal spindle is called a horizontal rice mill. Horizontal rice milling machine is divided into single roller rice milling machine, double roller rice milling machine and rice milling and wiping combination rice milling machine. The advantages and disadvantages of horizontal rice milling machine are:

Advantages:

(1) smooth operation. The bearing is only subjected to radial force, and the bearing stress and the whole machine torque generated by the unbalanced force are small. The horizontally installed white roller does not have high requirements for manufacturing and assembly, and the technical requirements for the corresponding structural components are not high.

(2) The volume and weight of the unit output are small. Due to the large axial thrust and the large rice grain speed, under the same feed material flow rate as the vertical rice mill, the diameter of the white roller and the annular area of the white chamber are small, the volume of the whole machine is small, the weight is light, the requirements of combined manufacturing technology are high, and the cost is low.

(3) It is convenient to disassemble and assemble the sand roller in the horizontal direction of the white grinding machine, saving time and effort.

(4) It is convenient and reasonable for two white rollers to be combined coaxially or in different axes in one rice mill.

Disadvantages:

(1) Gravity affects the centrifugal acceleration of rice grains, resulting in differences between the upper and lower parts of the white grinding chamber, affecting the uniformity of the white grinding degree.

(2) The number of rice knives is small, the material is hard, and some are not easy to adjust. For example, the fixed rice knives in the middle and lower parts need to be shut down for adjustment. Although the steel rice knives are wear-resistant, they are easy to damage rice grains, increasing the broken rice rate.

(3) Bran is easy to accumulate in the upper part of the white grinding room.

(4) The spiral groove needs to be manually repaired after abrasion. The quality after repair varies from person to person. The sand roller is 2~3 sections in series. After abrasion, it cannot be interadjusted or partially replaced, and the maintenance cost is high.

5. Wind-spraying rice milling machine

Wind-spraying rice milling refers to the method of continuously spraying air into the white roller during rice milling. The wind is sprayed from the inside of the white roller to the holes or grooves on the surface under a certain pressure. The role of wind spray has three aspects:

(1) Cooling and humidity reduction can dissipate the heat and a large amount of water vapor generated during rice milling, so as not to increase the rice temperature, thus improving and improving the rice milling process.

(2) The rolling of rice grains is increased. When the air enters the white grinding chamber, the volume expands and the pressure decreases, forming air mixed flow. The rice grains form rolling motion in the vortex, so that the rice grains are evenly grinded white and the phenomenon of over-grinding is avoided.

(3) The rice bran can be quickly discharged out of the machine, so that the load of the rice machine is reduced and the power consumption is reduced. The use of multi-machine spray water light grinding process is an effective way to improve rice yield and reduce broken rice, and is a feasible and effective method for processing high-refined rice.

6. Humidifying rice milling machine

Humidification rice milling is a new method developed on the basis of wind-blasting rice milling, that is, during the rice milling process, water mist is continuously sprayed into the white grinding chamber. Its working principle is: the high-speed and high-pressure water mist airflow is sprayed into the white grinding chamber, and many strong gas vortices are formed when moving around the grinding roller, so that the rice grains are continuously humidified, turned over and peeled during the rotation. On the one hand, the binding force between the wet rice skin and the inner layer is reduced, on the other hand, the friction coefficient between the surface of the rice grains is increased, so that the pressure required for grinding white is reduced, the crushing rate is reduced, and the rice yield is increased.

The choice of 2. rice mill

The choice of rice mill depends on the variety of raw rice and the quality requirements of the finished product. Generally, iron roller rice milling machine can be used for processing hard japonica rice. Sand roller rice milling machine and vertical sand roller rice milling machine should be used for processing soft indica rice. When grinding white by multiple machines, the sand roller is used for grinding white at the first pass, and the iron roller rice mill is used for the last pass, I .e. the sand roller is rough and the iron roller is fine.