Maquinas e implementos para a colheita (parte 2)

Summary

This video lesson covers various types of agricultural machinery used for harvesting and processing crops. It begins by explaining the workings of silage harvesters, emphasizing their design and function for cutting and transporting crops like corn. The lesson then shifts to coffee harvesters, discussing the physics behind their operation, including the resonance frequency of coffee fruits for selective harvesting. The video also touches on the evolution of coffee harvesting machinery, addressing challenges like plant damage and how modern equipment mitigates these issues. Finally, the instructor introduces the next topic on sugarcane harvesters, providing a comprehensive look at the machinery and techniques involved in crop collection.

Takeaways

• 😀 Silage harvesters can be static or mounted on tractors. Static ones require the crop to move toward the machine, while mounted ones move through the field.
• 😀 The principle of silage harvesters involves cutting, chopping, and transporting crops like maize, using rotating blades to fragment the material.
• 😀 Silage harvesters are equipped with a cutting mechanism that includes two counter-rotating cylinders to provide a controlled cut at the base of the crop.
• 😀 After the crop is cut, it is sucked into the machine, where it is chopped into small pieces by a set of high-speed rotating knives.
• 😀 Harvested material is then expelled through a transport system and can be deposited into a truck or container for further processing.
• 😀 Operators can adjust the speed of the knives or the feeding system to control the size of the chopped material, based on the desired fragmentation.
• 😀 Coffee harvesters operate based on the principle of resonance frequencies, where the machine vibrates at frequencies similar to those of coffee cherries to detach them from the plant.
• 😀 Coffee cherries, which come in different stages (green, ripe, and overripe), have distinct natural frequencies, which are used to selectively harvest them.
• 😀 The coffee harvester uses a vibrating mechanism to detach cherries, and by adjusting the machine's frequency, ripe cherries are collected while leaving the others on the plant.
• 😀 Modern coffee harvesting technology has evolved to reduce damage to coffee plants, with improved designs that allow for more efficient and selective picking.
• 😀 Semi-mechanized coffee harvesting systems use powered tools for vibration and manual collection, reducing the need for full mechanization but improving efficiency.
• 😀 Despite advancements, challenges in selective coffee harvesting remain, as resonance frequencies for various coffee cherry stages are not yet fully standardized.

Q & A

What is the primary function of silage machines (ensiladeiras)?

The primary function of silage machines is to harvest, chop, and transport specific agricultural products like cereals. These machines can be static, where the product comes to the machine, or mounted on tractors, as seen in schools and farms.

How do silage machines cut the crops, such as corn?

The silage machine uses a system with two rotating cylinders that cut the base of the corn stalk as it passes through. The cylinders rotate in opposite directions, creating a double cut, which allows the machine to chop the corn efficiently.

What happens after the corn is chopped inside the silage machine?

After the corn is chopped by the rotating blades, it is suctioned into the machine and then passed through a set of high-speed knives that further chop it into small fragments, which are then ejected into a transport system.

What options do operators have to adjust the silage machine for different types of products?

Operators can adjust the machine's settings, such as increasing the blade rotation or adjusting the feed speed, to control the size of the fragments. A slower feed allows for finer cuts, while faster speeds may result in larger fragments.

What principle does the coffee harvester use to harvest selectively?

The coffee harvester operates based on the principle of natural resonance frequency. The harvester vibrates at a frequency close to the natural frequency of the coffee cherries, causing them to detach from the plant without disturbing other parts.

Why is frequency resonance important in coffee harvesting?

Frequency resonance is crucial because it ensures that the coffee cherries, which have their own natural frequency, are harvested without disturbing the plant too much. The vibration helps detach ripe cherries while leaving unripe ones on the plant.

What challenges exist in selectively harvesting coffee with resonance frequency?

The challenge lies in accurately determining the natural frequencies of different coffee fruits (ripe, unripe, and green). Research is ongoing to find the most effective natural frequencies for selective harvesting, but a consensus has not been reached yet.

What alternative method is used for selective coffee harvesting if resonance frequency is not sufficient?

Instead of using resonance frequency, many modern coffee harvesters rely on the force of detachment, which helps separate ripe coffee cherries from the plant based on the different detachment forces of each stage of ripeness.

How have coffee harvesters evolved over time in terms of technology?

Coffee harvesters have evolved from simpler models, such as those that could only harvest one side of the coffee row, to more advanced machines that harvest both sides simultaneously, increasing efficiency. Today, self-propelled machines are also available.

What improvements have been made to reduce damage to coffee plants during mechanized harvesting?

Improvements in coffee harvesting machines have led to more delicate mechanisms that reduce the risk of breaking branches. This is achieved through better vibration control, which helps minimize damage to the coffee plant.