December 12, 2019

What fertilization problems can be solved with soil testing and formula fertilizing instruments?

Fertilizing operations are a very important part of agricultural production, affecting the quality, nutrition, and yield of crops. In modern agricultural production, even the most experienced agricultural workers do not dare to say that they will fertilize because of the past. In the face of the current soil environment, many of the fertilization experiences are no longer effective. The current fertilization program that is widely admired is the application of soil testing and formulated fertilizer applicators to perform soil testing and formula fertilization, that is, the use of soil testing and fertilizer applicators to test and analyze the relevant nutrients in the soil, based on the results of the tests and the crops Need fertilizer characteristics, formulate the type of fertilizer to be applied, the number of application, the application method and fertilization plan for the application period, and then apply fertilization according to the plan.

Soil Testing Formula Fertilizer

In fact, due to non-standard and unscientific fertilization effects, it has caused a lot of pressure on agricultural soils and caused many fertilization problems. The most direct effect is that fertilizers are applied more and more, but the effect of crop yield increase is not obvious. It is a decrement, but after applying the soil testing and formula application instrument, can these problems be solved? What are the fertilization problems that can be solved with the soil testing and formula fertilizing apparatus?

1. Types of scientifically selected fertilizers The main function of the soil testing formula and fertilizer application instrument is to measure soil. Through soil testing, producers can clearly know what fertilizers are missing from the soil according to the actual crops so as to help producers scientifically select fertilizer types. ,Organic fertilizers with inorganic fertilizers (fertilizers) with the application, NPK combined application, a large number of elements (nitrogen, phosphorus, potassium) with the use of trace elements in combination.

2. Scientifically determine the fertilizer dosage The soil testing and formula fertilizer application can reasonably determine the amount of fertilizer according to the soil nutrient content and the needs of the sowing crop.

3. Scientific application of fertilizers Soil testing and formula application instruments can also scientifically apply fertilizers based on the characteristics of fertilizers to ensure that crops do not suffer from fertilizer damage.

4. Scientific determination of the use of fertilizer Fertilizer meter can be used at any time to quickly detect soil nutrient conditions, and according to the crop's fertilizer requirements, soil conditions, crop harvest times scientifically determine the fertilizer application period to ensure the effect of fertilization .

The soil testing and formula application instrument has played an important role in promoting soil testing and fertilizing techniques. At the same time, it has made important contributions to improving agricultural fertilization techniques, improving fertilization effects, and improving the soil environment in agriculture. Development has laid a solid foundation.

Tapered Roller Bearings

 

Tapered roller bearings are mainly suitable to carry combined load---radial load and as well as axial load; While steep angle tapered roller bearings (27°-30°) can carry the combined load dominated by the axial load. The tapered roller bearings are separable bearings, their internal assemblies and outer rings can be mounted separately; the radial clearance and axial clearance can be adjusted when mounting and interference fits are also allowed.

Structures

1.30000 type single-row tapered roller bearings

This type of bearings can accommodate the axial displacement and axial load on one direction on the shaft or housing. An additional axial force will be generated under the action of radial load, so the outer ring and inner ring inside the two bearing slewing should be mounted with their end faces with same name opposite each other. When applied separately, the applied axial force must be larger than the additional axial force.

2.350000 and 370000 types of double-row tapered roller bearings

These types of bearings comprise one double-raceway outer ring (one double-raceway inner ring) and two inner rings (two outer rings). There is a spacer between the two inner rings (two outer rings), To change the thickness of the spacer can adjust the bearing clearance. They can carry radial and double-direction axial load simultaneously.

3. 380000 type four-row tapered roller bearings

This type of bearing adopts two double-raceway inner rings, one double-raceway outer rings and two single raceways. There are spacers between inner rings and outer rings used for adjusting bearing clearance. They can accommodate large radial load. But their limit rotational speed is low so they are mainly applied to heavy-duty machines such as rolling mills.

Cage materials

Tapered roller bearings generally adopt steel sheet cages, when with too large sizes, use welded steel sheet cages or steel pinned solid cages.

Permissible tilt angle

Generally, inclination is not allowed between the shaft and the housing on the tapered roller bearings. If any, it should not exceed 2'.

Tolerance and Clearance

Generally, the tolerance classes of tapered roller bearings is P0, also can produce higher tolerance classes bearings according to the requirement of users. The tolerance value is showing in the section [the tolerance of rolling bearing".

Users can adjust for practical clearance for the single-row tapered roller bearings according to different demands. The radial clearance of double-row and four-row tapered roller bearings is showing in the table 1.

Dynamic equivalent radial load

Single-row tapered roller bearings:

                Pr = Fr   When Fa/ Fr≤e

         Pr=0.4Fr+YFa     When Fa/Fr>e

When applying single-row tapered roller bearings in pairs, the additional axial force must be counted when computing the equivalent dynamic load of the bearings. The axial load magnitude is influenced by mounting methods and the applied axial load and the detailed computing method is same as angular contact Ball Bearings.

The additional axial load on the single-row tapered bearings can be approximately computed with the equation below:

             S=Fr/2Y

Double-row tapered roller bearings:

Fa/Fr≤e    Pr=Fr+Y1Fa

Pr=Fr+Y1Fa    When Fa /Fr≤e

Fa/Fr>e     Pr=0.67Fr+Y2Fa

Pr=0.67Fr+Y2Fa   When Fa/Fr>e

Static equivalent radial load

Single-row tapered roller bearings:

P0r=0.5Fr+Y0Fa   

If P0r<Fr, take P0r=Fr

Double-row and four-row tapered roller bearings:

P0r=Fr+Y0Fa  

In the equation:

Fr Actual radial load of the bearing

Fa Actual axial load of the bearing

e.Y.Y1.Y2.Y0  see the bearings dimension table.

In order to prevent damaging sliding generated between the rollers and raceway, a minimum radial load must be acted on the bearing. The calculating formula is:

  Frmin=0.02C   

In the equation: Frmin     Minimum radial load

                 C       Basic dynamic radial load rating 

Tapered Roller Bearing

Single Row Tapered Roller Bearing,Double Row Tapered Roller Bearing,Four Row Tapered Roller Bearing

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