Exclusive Test Drive Imperador 2500 self-propelled sprayer, from Stara

The Imperador 2500 is the newest product in Stara's line of self-propelled sprayers. Launched in February, at the last edition of the Rural Show, in Cascavel (PR), it joins the other three models already offered by Stara. This sprayer is already on sale and has arrived to complement the brand's portfolio, adding an intermediate model between the two existing ones, meeting customer demand. This class of self-propelled vehicles is the one with the greatest demand in the country.

This new model is being presented in two versions, Intermediate and Top. In the Top version, the additions of intelligent wheel rotation, front and rear, the continuous recirculation system up to the end of the bar and the nozzle-to-nozzle flow cutoff are offered. In the Intermediate version, the flow is cut per section and recirculation continues until the end of each section.

To learn about this new product and do the Test Drive for this edition, we went to the town of Bom Sucesso, in the municipality of Carazinho (RS). At a time of great climatic adversities for the state of Rio Grande do Sul, caused by excessive rainfall, the weather provided us with a day of clear skies and few clouds to further test this new product from Stara.

Vehicle

The Imperador 2500 is a self-propelled sprayer equipped with an engine, transmission, electrical and hydraulic circuits and a displacement and steering system, based on four driven wheels.

For propulsion, a Cummins four-cylinder engine with maximum power of 213 hp is used, with electronic fuel injection management, with turbo intercooler, located at the rear of the machine. Access to the engine is via a rear ladder for maintenance and inspection. Also located at the rear is the hydraulic and transmission oil reservoir, ISO VG 68, with a capacity of 60 liters, the level of which can be easily monitored using a column display next to the reservoir.

The fuel tank with a capacity of 250 liters, as well as the filling hole, is positioned on the front of the machine, close to the ladder leading to the cab.

The power transmission is of the Bosch hydro-electronic type, with tilt sensor (ramp) and integral traction control for Bosch individual wheel motors and Bonfiglioli reducers.

The steering system is independent for each wheel, allowing the sprayer to maintain a precise trajectory, even on uneven terrain, important for maintaining the trajectory and application precision.

There are three operating modes: “maneuver”, “transport” and “work”, with speed limits of 10 km/h, 40 km/h and 25 km/h, respectively. For safety, the configuration provides that above 18 km/h the rear wheels are disconnected, but the front wheels are permanently activated. It is important to highlight that wheel motors are not slaves, dependent on each other, but completely independent.

The four driving wheels use radial tires, specified as 340/85 R38 with a plant separator or metal rail cleaner at the front. The gauge between wheelsets on the same axle is hydraulic and can be adjusted between 2,60 and 3,20 meters, with adjustment by the operator while moving from the cab. The free span is 1,60 meters.

The Imperador 2500 uses a chassis for its structure, with a front part that supports the fuel tank, the front ladder and the cabin. The rest of the structure is all joined together by welding and uses a tubular profile. By the way, the industrial quality of the welding joints and the quality of the screwed components must be praised.

The suspension system is of the active type, using four air pockets, Firestone brand one on top of each wheelset, so that they can have independent movement, which favors adhesion to the ground. However, to improve stability, the system promotes joint pressure action, but allowing one air pocket to mold more than the other.

Very useful in maintenance, a pneumatic system with spiral hose and air gun offers convenience in cleaning filters and other engine components.

Spray system

The syrup tank is placed in the central position, just behind the cab and has a capacity of 2.500 liters. Filling is carried out from the side of the machine and at the bottom of the tank there is a mechanical agitator, with a stainless steel propeller that complements the mixture of the product with the liquid through continuous hydraulic agitation, through the action of the pump.

The system that generates pressure for spraying uses a Hypro pump with a flow rate of 430 liters per minute with a double filtration system, which prevents the nozzles from clogging.

The circuit starts with the side supply, passing through a filter that goes to the pump or return. If it is for the centrifugal pump, the inlet is in the middle and the outlet is on the side, then going to the register, with double post-pump filtration, passing through the flow meter and then to the bars. The valve directs the flow to the sprayer or to the incorporator. Another flowmeter was placed on the return line. At the exit of the product to the bars, a set of valves directs the flow, which is filtered again before going to each side section of the bar or to the rear section. From the filters placed at the inlet of each section of the bar, the syrup flow will go directly to the nozzles.

For those producers who use ready-made syrup, insertion takes place through the side dispenser and for those who mix the product directly in the water in the tank, there is a side incorporator, with 35 liters of capacity, with packaging washing.

On the outside of the cabin, there is a visual scale of the tank's syrup level, expressed every 100 liters, which can be observed by anyone outside the machine, mainly working on the fueling. The operator will be able to identify the volume of syrup remaining in the tank using the Topper 5500 VT controller. To do this, simply inform the machine control monitor when the reservoir is completely full. By intelligent calculation, the system will inform the volume available in the reservoir, taking into account the volume that has already been applied. In front of the main tank there is a clean water tank with a capacity of 250 liters, i.e. 10% of the capacity of the syrup tank, which is used to clean the syrup tank and the machine's spray circuit.

The Imperador 2500 has a continuous syrup recirculation system. In this case, the machine keeps the syrup in constant circulation in the reservoir and also in the machine's pipes, which provides homogeneity of the mixture and exact concentration of the pesticide at the time of application. A system like this also helps spraying to be cleaner, eliminating residue from previous applications and improving the durability of spray components. This continuous recirculating syrup system runs even when the bars are closed.

Application bar

As a particular feature, patented by the manufacturer, the application bars are located in the center of the machine. This assembly provides better weight distribution over the wheelsets in dynamic conditions and, therefore, greater vehicle stability, even with variations in the volume of grout in the tank.

The side bars are made of latticed carbon steel with E-Coat paint, which forms a transparent, smooth and highly self-cleaning solid protective layer based on crystallized silica, ensuring greater protection against corrosion. The rear bar is made of aluminum, with an interlaced structure that protects the nine nozzles, spaced 0,5 meters apart. The piping that allows the syrup to be conveyed is entirely made of stainless steel, connected by rubber hoses.

The application bars have a total length of 30 meters, being divided into three sections on each side and a central part, placed at the rear of the equipment. The bars can be positioned at a maximum height from the ground of up to 2,20 meters and a minimum height of 0,80 meters. The rear segment of the bar works in coordination with the application side bars, so that when you set the height of the side bars, the rear bar automatically adjusts as well. Furthermore, when the side bars are closed for transport, the rear section of the bar retracts the ends, so that the total width is 3,20 meters, an important measure that allows autonomous movement, without the need for the use of a truck. board.

The mechanical system used to open and close the side bars is quite interesting. Considering the three sections of the bar, the first, closest to the chassis, when in transport position is supported on two stops, one on each side of the machine. When opening, the hydraulic system brings the bar up and then opens it. The second section, which was retracted above the first, opens and, by means of a trigger device, upon completing the opening, triggers a command for the third section which opens forward. Closing occurs in reverse, the third section is hinged backwards, the second upwards over the first, rises and turns backwards, resting again on the rear stop.

When the bar is lowered, seeking working height, there is a ball joint that compensates for the movement, always bringing the bar to a vertical position.

In the third section, at the end of the side bars, where the last four nozzles are located, there is an articulated safety mechanism, made up of springs and steel cables, which allow this section to be retracted when it hits an obstacle, protecting the rest of the structure. . After disarming, the section returns to the initial position, due to the effect of the spring and cable.

Considering that in total there are seven sections, three for each side and one for the rear, the Imperador 2500 in its Intermediate version cuts in sections, while in the Top version the nozzles are switched off unit by unit, that is, nozzle by nozzle, by command of the Topper, interrupting the flow of product in areas that have already been applied, reducing overlap and waste. The nozzle holders are the Trijet type from the Hypro brand, with a stainless steel spherical valve manufactured by KZ, especially for Stara.

Cabin

The cab, also manufactured by Stara, features a curved windshield at the front and flat at the sides, with access through the door on the left side of the machine. On the right side there is a door that can be used as an emergency exit and this is where the fuse panel is located.

Access is via a seven-step front staircase with a non-slip surface, connected to the parking brake, so that all you need to do is release the brake to retract the ladder, while applying the brake promotes automatic lowering. A small tank of clean water was positioned below the stairs for hand washing. Supporting the cab, four rubber cushions for support and vibration reduction.

Inside, the steering column is adjustable for approach, tilt and depth. The main seat customized with the brand is equipped with pneumatic cushioning and has the console attached to it, so that, as the seat moves forward and backward, all the instruments positioned on the side panel follow along with it. A companion seat, mainly used for training, is positioned to the left of the main one.

On the console, the multifunctional control can be used to control the direction of movement. Simply set a target speed and push the control forward, in the most advanced position, and the vehicle will assume this speed. There are switches at the front, back and bottom. The rear buttons are used to control speed, increasing or decreasing, the one below turns the autopilot on and off, and on the front face two sets of arrow-type switches provide control of the application and positioning of bars and frame height, in addition to a central unit that activates the spraying.

The Topper 5500 VT controller monitor is the only interface, which is positioned on the right front pillar of the cab and serves the engine, transmission and application. It presents information about the operation, such as the total area worked per field and the amount of crossing area. Engine information is displayed regarding vehicle operation, such as speed and temperature, fuel volume in the tank and instantaneous speed. Fully interactive and configurable, with a touch screen, it shows in the center a figure of the machine and the paths to apply product and those already applied. With it, you can also turn on and off various functions, from the autopilot, the pressure system, the syrup mixer, etc.

Still complementing the cabin, it is worth highlighting that the room temperature conditioning is completely digital and that there is, as standard, a radio with Bluetooth connection and object holder. The GPS antenna and a gyroscope are positioned on the roof of the cabin, as a warning system during transport.

Technology

An important technological highlight refers to the use of the transmission, so that the equipment allows the operator to define a target speed at which he wants the spraying to occur and the integrated hydro-electronic system defines the engine rotation and transmission operation, increasing or decreasing the pressure and flow of the pump, to maintain this speed. This occurs without the need for operator intervention.

Another highlight that we saw during the period we worked with the equipment is the intelligent rotation or trail of the wheelsets. This technological item allows the rear wheelset to pass in the same track as the front wheelset, reducing the turning radius and greatly reducing crop crushing. For safety reasons, intelligent turning is disabled when operated at speeds above 18 km/h, leaving only the front wheels moving.

Furthermore, the Imperador 2500 comes with an integrated GPS system. The customer who purchases the machine receives the corrected TerraStar signal free of charge from Stara for a period of one year. After this period, the customer can choose to renew the corrected signal, with an annual charge, or for an open signal, free of charge. The telemetry system is also completely free and, in this service, you can monitor the machine in real time, informing you with alerts when an item does not comply with what has been parameterized.

The company offers a function in the Topper controller that accesses Stara's Conecta service, which helps the customer by connecting them directly with the company's after-sales area, in real time.

The Imperador 2500 has a TD3 model autopilot responsible for ensuring the reduction of failures, overlaps and traffic control for future activities, providing information to the producer. Other technological items are offered, such as the Syncro radio data transmission system and Weather Station with temperature and humidity functionalities, which can be purchased as options.

It is also possible to download the Stara Spraying application to any mobile device, from the Google Store and Apple Store, and use it as another assistance tool, completely free of charge for information from the Beak-to-Beak System and Stara Telemetry.

Furthermore, the Imperador 2500 has Stara Machine Monitoring, an exclusive service that monitors the machine in real time. When any monitored item is not in accordance with what was parameterized, alerts are displayed on the Topper screen and are sent to Stara Telemetry. If this alert is not corrected, the company will notify you via WhatsApp and, in critical cases, by phone call.

Test location

The area of ​​our Test Drive, in the town of Bom Sucesso, in the municipality of Carazinho (RS) was gently sloped, with soybean stubble and perennial ryegrass. The sprayer was programmed for different target speeds and an application rate of 150 liters per hectare. Stara's Product Marketing employees, engineers Thomas Liska, coordinator, and Matheus Henrique Baumgratz helped us in this field evaluation. From the Engineering and Product area, engineers Cícero Roessler, Juliano Perin and Willian Alexandre Gomes supported us.

Jose Fernando Schlosser,
Henrique Eguilhor Rodrigues
Daniel Ciro de Souza,
Agrotechnology Lab - Nema - UFSM