LT5532B - Mobile device for thermal deracinating of weeds - Google Patents

Abstract

The invention relates to agriculture and can be used for deracinating of weeds, by wet water steam. Purpose of the invention is to create effective mobile device for thermal deracinating of weeds by wet water steam. For that purpose is construct spread device of water steam, which changes speed and direction of water steam. Canals of spread device with adjustable cross section are suitable to process of adiabatic expansion.

Description

The invention relates to agriculture and can be used as a device for killing weeds in crops with wet water vapor. The object of the invention is to provide a mobile weed thermal steam eradication device which would increase the efficiency of thermal weed eradication and reduce the water vapor (heat) cost for thermal destruction of plants. This goal is achieved by creating a water vapor discharge diffuser that changes the speed and direction of the water vapor flow. For this purpose, channels of adjustable cross-sectional area spreaders are used, which satisfy the regularities of the process of adiabatic expansion.

The invention relates to agriculture and can be used as a device for weed control in crops with wet water steam.

The known portable weed control device (EPA No. 1. 0920802, 1999) consists of a steam generator, a spreader and a tube which connects the steam generator to the spreader. The baffle consists of a hood with steam inlets and outlets. The disadvantage of this unit is that weeds are removed under the hood and cannot be used in mobile, mechanized weed control technology.

Also known as a weed killer (SU a. 1. No. 1780676, 1992) is water vapor, the purpose of which is to improve productivity (quality) in vineyards. The unit consists of a bracket, water level regulator, water tank, steam generator, spreader. The disadvantage of this unit is that the water vapor diffusion is controlled manually, the water vapor discharge rate is high, the outgoing water vapor flow is uncontrolled, which causes intensive mixing of water vapor with ambient air, which affects the formation of water vapor / air mixture heat transfer coefficient, this increases the water vapor consumption.

The closest to the proposed one is a steam weed eradicator (EP A L 1038440,2000) with a movable hood. The hood adjusts the water vapor inlet and outlet through horizontal plates. Horizontal plates allow water vapor to be vented to the side or center of the enclosure. As the unit moves, weeds are removed under the hood. The disadvantage of this unit is that the steam is released perpendicular to the surface of the soil, the entire plant is thermally destroyed, so the weed thermal eradication process requires a longer shelf life, which increases the water steam and heat consumption.

The object of the invention is to provide a mobile weed thermal steam eradication device which would increase the efficiency of thermal weed eradication and reduce the water vapor (heat) cost for thermal destruction of plants.

This goal is achieved by creating a water vapor discharge diffuser that changes the speed and direction of the water vapor flow. For this purpose, channels of adjustable cross-sectional area spreaders are used, which satisfy the regularities of the process of adiabatic expansion. Spreaders are used extensively in agricultural machinery, such as crop sprayers, hand sprayers. weed thermal eradication equipment, etc., but such a spreader design used to increase the efficiency of the weed thermal eradication and reduce the water vapor cost in the weed thermal eradication process is an essential distinguishing feature of the device that achieves the object of the invention.

In the drawings, Figs. 1 shows a diagram of a mobile weed thermal steam eradication device; FIG. 2 is a diagram of a water vapor diffuser; FIG. 3 - theoretical model of thermally damaged plant stem tissues; FIG. 4 - Thermal damage of plants in the ring using the proposed water vapor release diffuser during production tests; FIG. 5 - thermal damage of the whole plant by water vapor using a closed enclosure during production tests; FIG. 6 - Schematic of flat surface tests using the proposed water vapor release diffuser; FIG. 7 temperature variation on soil and plant surface at 0-15 mm height during thermal weed control using the proposed water vapor discharge diffuser at different wet water vapor release distances A from the crop.

The mobile weed thermal eradication unit consists of: tractor with mounting structure 1, water steam boiler 2, steam dehumidifier-superheater 3, main steam supply pipe 4, steam distribution manifold 5, steam spreaders 6, positioning device of steam spreaders on the soil surface 7.

The device works as follows. As the tractor 1 moves, the wet water steam is produced in the steam boiler 2 after passing the steam dehumidifier 3 through a main supply line 4 to a steam distribution manifold 5 where the water steam is distributed to the steam distributors 6. The height of the water steam distributors 6 .

In the variable cross-sectional spreader channel 8, a plate 9 is attached to which the water vapor flow deflector 10 is attached. Adiabatic expansion of water vapor occurs in the channel 8 of the variable cross-sectional area. Due to the diffuser channel surface shape 12 and the water vapor flow deflector surface shape 13, the variable channel cross section satisfies the regularity of the variation of the water vapor flow adiabatic expansion parameters pv ^k = const. The direction of the axis of the mouth of the water vapor outlet is chosen so that the water vapor flows at an acute angle to the soil surface and directs the outgoing water vapor flow at the soil surface.

The moist water vapor released in this way, when sliding over the soil surface, thermally damages not the whole plant, but only the stem of the plant in the ring. Therefore, the process of thermal weed control with wet water steam does not require heating the entire plant. The weeds so treated have a thermal effect of 1.0 to 2.0 s and water vapor consumption is lower than when the whole plant is heated.

The proposed mobile weed thermal eradication unit was manufactured and tested at the Lithuanian University of Agriculture test station during production tests. Laboratory tests of individual units were performed at the LUA Thermal Measurement Laboratory. Tests were performed using a sealed hood and a proposed water vapor vent. Temperature on the surface of plants and their environment during thermal weed control was measured. The temperature of the plants destroyed under the hood was close to 100 ° C using a closed hood. Using the proposed water vapor release diffuser, the plant stem was thermally damaged by a ring at a height of 0-15 mm from the soil surface. When the water vapor was released from the plant at a distance of 8, 10, 12, 14 cm, the temperature on the stem surface of the plant was 81 ° C, 75 ° C, 72 ° C, 70 ° C, respectively. In this way, the plants were provided with a high-temperature environment that destroys them. Laboratory studies have shown that thermal destruction of the plant stem, which is an important vital organ of the plant, is not required for thermal destruction of the plant as a whole. All test conditions were the same in all cases.

Claims (2)

Definition of the Invention 1. A mobile thermal weed control unit equipped with a tractor mounted tractor, water steam boiler steam dehumidifier - superheater main steam supply manifold steam distributor, steam diffusers characterized in that the variable cross section water vapor discharge diffuser channels ( ) giving the variable cross-sectional channel an adiabatic expansion channel shape by controlling the velocity and direction of the outgoing water vapor stream. 2. A mobile thermal weed control device according to claim 1, characterized in that it has a positioning device (7) for positioning the steam spreaders on the soil surface.