How to solve the problem of wheat harvester running grain? Fan, screen should pay attention to, dynamic adjustment is the key

Release time:2023-05-23    Click:201

The annual wheat harvest is starting again, and to the wheat combine harvester battle season, every year in wheat harvesting operations, there are a lot of agricultural machinery users of the harvester in use will appear to run grain phenomenon, run grain not only waste food, more likely to cause the contradiction between agricultural machinery and farmers, sometimes agricultural machinery not only receive the money to receive wheat, It may have to pay farmers more for the damage. Next, we will analyze the reasons for running grain and leaking grain.


First, let's look at what food running is. The so-called grain running means that there are too many grains in the wheat bran discharged from the back of the cleaning screen, which exceeds the stipulated national standard. Simply put, the cleaning loss is too large. The main reasons for the loss of cleaning are as follows:

First, the air volume of the cleaning fan is too large, and the wheat grains are blown directly out of the screen box in the operation, resulting in loss exceeding the standard; The second is that the air volume of the cleaning fan is too small, the wheat grains and straw are not blown loose, the grains are not separated, resulting in the screen surface running grain, loss exceeds the standard; Three is the sieve open too large, so that the wheat straw is blocked between the sieve pieces, resulting in the sieve blockage, wheat grains can not all fall from the sieve, resulting in the screen surface run grain, loss exceed the standard; Fourth, the sieve is too small, so that the grain can not effectively through the sieve into the grain auger, resulting in the sieve surface running grain, loss exceed the standard; Five is the wind direction of cleaning fan and screen box does not match, resulting in some on the screen blockage, some under the screen blockage, making wheat grain loss exceed the standard; Six is the screen box horizontal amplitude adjustment is wrong, resulting in wheat grain loss exceed the standard; Seven is the speed is too fast, feeding quantity is too large, resulting in cleaning too late, so that the loss exceeds the standard.

According to the above reasons for grain running, we can adopt the following methods to solve the problem. First, let's take a look at the adjustment method of fan air volume:

Wheat harvester cleaning fan for centrifugal structure, the main components include: volute, impeller, fan shaft, wind plate, sprocket, pulley and so on. When installing the impeller of the cleaning fan, ensure that both ends of the blade and the inner wall clearance of the volute are consistent; The role of air regulating plate is to adjust the intake air volume by changing the opening of the air inlet. Two pieces are commonly used to adjust the opening of the left and right air inlet respectively. Some models have two spare parts which can be installed symmetrically with the two pieces of the original machine for further throttling. The speed of the cleaning fan is adjustable, the adjustment method is: by changing the thickness of the gasket in the middle of the fan pulley to change the working diameter of the pulley to achieve the organic adjustment of the speed (when the gasket is increased between the two pieces of the pulley, the gap between the two pieces of the pulley will be larger, the working diameter of the pulley will be smaller, the fan speed will be increased; When the gasket between the two pieces of pulley is reduced, the gap between the two pieces of pulley will be smaller, the working diameter of the pulley will be larger, the fan speed will be smaller), the fan speed is generally in the middle position when the harvester leaves the factory. In the process of harvest, the air volume should be adjusted in real time according to different wheat varieties, yield, maturity and other field operating conditions, so as to obtain the appropriate air volume, and match with the opening of the screen, so as to improve the cleaning effect.


Here we look at the corresponding treatment method of running grain:

One is that the air volume of the cleaning fan is too large. At this time, the air volume should be reduced according to the air volume of the wheat grain. One method is to reduce the gasket between the fan pulley, so that the working diameter of the pulley is increased, so that the fan speed decreases and the air volume is reduced. Another method is to use the air regulating plate, the opening of the air regulating plate is reduced, so that the intake air volume is reduced, thus reducing the air volume).


Second, the air volume of the cleaning fan is too small. At this time, the air volume should be increased according to the air volume of the wheat grain. On the contrary to the method of reducing the air volume, one method is to increase the gasket between the fan pulley, making the working diameter of the pulley smaller, making the fan speed rise and improving the air volume; Another method is to use the air regulating plate to adjust, adjust the opening of the air regulating plate to increase the intake air volume, so as to improve the air volume).


Three is the screen open too large, need to adjust the opening between the screen. Sieve opening principle is "before small after large", the general minimum is not less than the length of the crop grain, the maximum is not more than three times the length of the crop grain; When the weather and crops dry tail screen can be opened, weather and crops wet tail screen must be turned down or closed. When adjusting, the opening of the front of the upper sieve should be greater than the length of the crop grain, and the opening of the back of the upper sieve should be twice the length of the crop grain. The lower sieving degree is basically consistent with the opening degree of the front of the upper sieving. The specific opening degree is subject to the non-running grain during the harvesting operation.


Fourthly, the screen is too small, the adjustment method is the same as the third article, which also follows the principle of "small before large after". When adjusting, the opening of the front of the upper sieve should be greater than the length of the crop grain, and the opening of the back of the upper sieve should be twice the length of the crop grain. The lower sieving degree is basically consistent with the opening degree of the front of the upper sieving. The specific opening degree is subject to the non-running grain during the harvesting operation.


Five is the cleaning fan wind direction is not correct when the adjustment, when the screen is easy to plug, the fan volute front left and right sides of each fixed bolt removed, the volute was installed on the support plate to install below the support plate, so that the wind blows up the front of the screen; When the screen is easy to jam: add gaskets or nuts between the fan volute and the support plate, and then tighten the fan fixing bolt.


Six is to adjust the horizontal amplitude of the screen box, the adjustment method is: loosen the screen box drive shaft on both sides of the bearing seat fixing bolts, forward adjustment, screen box horizontal amplitude increases, backward adjustment amplitude decreases, adjust the screen box amplitude, one is the horizontal amplitude on both sides of the screen box to be equal, two is generally not less than 38 mm (different models of the technical parameters, specific specifications shall be subject to).


Seven is the speed is too fast, the feeding amount is too large, resulting in cleaning too late, loss of excessive adjustment. At this time, there is one of the most effective methods, right, is to reduce the speed of the operation, as long as a reduce the speed of the operation, the feeding quantity becomes smaller, the cleaning too late to cause loss exceeding the standard situation will change immediately. In fact, there are a lot of times cleaning loss exceed the standard and the pursuit of efficiency, the operation speed is too high, it is suggested that the speed of the operation should be moderate, in order to clear the loss does not exceed the limit, and according to the yield per mu real-time adjustment, when the yield per mu is high, the operation speed must slow down a little, and when the yield per mu is low, the operation speed can be as fast as possible.


Wheat harvester operation process is a process of constant adjustment, according to the maturity of crops, weather, wet and dry degree, varieties, per mu yield, early, late operation time and other real-time adjustment, only constant adjustment can make the harvester in the best operation technology state, high quality, efficient completion of the summer wheat harvest work.

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