RU59941U1 - SPRAY TEST STAND - Google Patents

Abstract

The sprayer test bench belongs to the agricultural industry and is designed to set up sprayer sprayers in the laboratory. It contains an electric drive, means for supplying and regulating pressure, means for distributing the working fluid through the spray boom, a system for diverting the supplied fluid, means for simulating wind speed in the field, means for simulating the movement of the atomizer in the field, a flatbed scanner for discrete recording of the image of the spray density. The rod has the ability to be located above the classifier table to account for the flow rate of the working fluid and the uniform distribution across the width of the spray jet and above the belt conveyor with an adjustable speed of movement to determine the dispersion of the spray and the coating density of the treated surface, which is carried out using flexible hydraulic communications. The test results are cards on which a working fluid is applied using a means of simulating the movement of the sprayer across the field. Card processing is done using personal computer software. They are scanned, and the resulting images are saved as a graphic file with the extension .bmp. After that, a histogram consisting of three areas is built in Adobe Photoshop. The first area reflects the content of shades of black. The second area corresponds to the reflection of the content of shades of white. At the last stage, the percentage of color in the region of interest of the histogram is determined. The proposed test bench for spray guns and the method of processing the obtained results allows to increase the number of studied characteristics, as well as to reduce the time for processing cards and obtaining results by an order of magnitude. This ensures the completeness of the study of various types of nebulizers, and reduces labor costs.

Description

The utility model relates to agricultural engineering, in particular, to devices for tuning and researching sprayers.

A known bench for testing and calibration of atomizers AC No. 41149 [1], simulating field tests, which contains a belt conveyor with an adjustable speed and a rod installed with the possibility of free movement on flexible hydraulic communications both in the vertical and horizontal planes, and located above "Running" surface (conveyor), on which cards are placed for the study of nebulizers in accordance with OST 10 6.1-2000. According to the method described in OST 10 6.1-2000, the density of the coating and dispersion of the spray liquid is determined as follows. As a working fluid use 1 ... 2% solution of nigrosine or other intense water-soluble dye. The coating thickness and dispersion of the spray are determined on coated paper cards of 50x70 mm in size, treated with a 3 ... 5% solution of paraffin in toluene (orthoxylene) to reduce the spreading of trapped drops. When processing each

the card is separately immersed in the solution, removed from the solution and placed in the dryer. Before conducting the experiments, the registration cards are placed according to the appropriate scheme, depending on the crop. After drying, the cards are removed, neatly stacked and sent for analysis.

When assessing the density of the coating on the treated surface, the cards are distributed into 5 groups as a percentage of the total number of cards by the working width: I - untreated; II - with a density less than acceptable in terms of specification; III - with density within TK; IV - with a density of more than 150 pcs / cm ² ; V - flooded.

Cards of groups IV and V are not analyzed. The thickness of the coating is determined by counting the drops on the cards using a microscope. At the same time, at least 5 strips 20 mm long should be viewed. The streaks to be viewed should be located in different areas of the card. When calculating the drops, the scanned area is taken into account. The density of the coating is determined by the formula:

,

where Po is the density of the coating, pcs / cm;

No is the total number of recorded drops, pcs;

Fo - scanned area, cm ² .

The dispersion of the settled drops on the cards is determined as follows. Cards of all repetitions are visually distributed in percentage terms into three groups: conditionally small - up to 150 microns, medium - 150 ... 300 microns, large - over 300 microns.

From each size group, two characteristic cards are subjected to analysis to determine the mass median diameter of the droplets. When processing cards, a drop sample is formed, consisting of a certain number of measured drops, distributed by size classes. The method for determining the dispersion of the spray consists of

processing cards, calculations and statistical processing of the results. During processing, the card is viewed in stripes with a length of L = 50 ... 60 mm. The width of the strip is determined by the number of divisions of the millimeter grid. When viewing, record the number of drops in each class of drop sizes, the number of scanned bands for each class of drop sizes. Next, carry out mathematical processing of the results.

The test result is indicators, the main among which are the degree of coverage with drops of the treated surface and the diameter of the drops.

The disadvantage of this processing method is that it is based on the use of manual microscopy, which significantly increases the complexity of processing the test results. The disadvantage of this device is the lack of a tool that simulates the wind speed on the field.

Another method of processing cards [2] is that after the droplets have dried, the surface of the cards is scanned on a computer, the image scale is increased, and, applying a millimeter grid to the enlarged image, information is obtained to evaluate the quality of the atomizer. Further, all calculations are carried out in accordance with the method according to OST 10 6.1-2000, described in the previous analogue, but without manual microscopy.

The disadvantage of this method is the complexity of manual counting. The disadvantage of the device is the same as in the previous analogue.

Common disadvantages of the described devices and methods for processing the results are: the lack of a tool that simulates the natural wind speed in the field to obtain more accurate and objective data on the degree of coverage of the treated surface with drops and the great complexity of the processing of the obtained data.

The aim of the proposed technical solution is to improve the process of obtaining objective results

testing of spray guns (taking into account the effect of wind speed on the sprayer operation) at the stand АС №41149 and reducing the laboriousness of the card processing process.

The goal is achieved by installing a centrifugal fan with a guided air flow on the frame, which simulates the natural speed of the wind and the use of a flatbed scanner, computer and its software when processing cards.

Figure 1 shows a diagram of a device. The stand consists of an electric motor 2, pump 3 and filter 4 connected to the tank 5 and the water mixer 6. The pressure generated by the pump is controlled by pressure gauges 7 and 8, and is regulated by the pressure regulator 9. The device is controlled through the control panel 10. The liquid in the tank 5, via hydraulic communications 11 it enters the boom 12 with spray guns 13 and is sprayed over the classifier table 14, flows down the spouts 15 into the graduated cylinders 16 and returns to the tank 5 through the groove 17. The boom with sprayers is mounted above the “running” belt 18 and the vertical supports 19 control rod adjustment. According to OST 10 6.1-2000, cards 20 are located on the “running” belt 18. To simulate the wind in laboratory conditions, a mobile centrifugal fan with a guided air flow 21 operating from the control panel 10 is installed on frame 1.

The device operates as follows. To measure the fluid flow rate, the angle of the spray pattern and the uniform distribution of the working fluid across the width of the test spray gun, the rod 12 is placed above the distribution table-classifier 14. The device turns on on the control panel 10. The electric motor 2 and pump 3 start to work through the filter 4 and the pressure regulator 9 delivers the working solution from the tank 5 with a water mixer 6 for hydraulic communications 11 to the rod 12, on which, with a certain step, the spray guns are fixed 13. The fluid from the spray gun 13 is sprayed over distribute nym stolom-

classifier 14 and flows from the nozzle 15 into the graduated cylinders 16. After the measurement results are fixed, the liquid is rotated by the graduated cylinders 16 by 120 ° and drained into the tank 5 through the chute 17, which reduces the time required to prepare a new experiment.

To measure the diameter of the droplets and the degree of coverage of the treated surface, a spray boom is placed above the "running" tape. The rod 12 is located on the rack 19 to the required processing height above the "running" belt 18. Cards 20 are located on the "running" belt. To obtain more objective results, the centrifugal fan 21 is turned on to the control panel 10 and the air flow generated is directed. The motor 2 is turned on and, with the steady state and the fan running, the working fluid in the tank 5 is applied to the cards when the tape is moved in a horizontal plane. After drying, cards are collected and processed. Directional air flow is necessary so that droplets with a diameter of less than 100 microns are carried away by the wind, rather than deposited on the cards, distorting the results. The “running” tape, on which the cards are discretely located, imitates the speed of the unit during spraying, and the fan - the wind speed on the field.

After the cards have dried, they are scanned using a flatbed scanner, and the resulting images are saved as a graphic file with the extension .bmp. Scanning is performed using the software included with the scanner. In this case, the image is scanned in black and white (in the settings there may be shades of gray or a black and white photo). A file saved with a .bmp extension is opened in Paint (a standard software application for the Windows operating system) and saved as a monochrome drawing with the original extension. During this saving, a gray tint is automatically removed from the drawing, and black and white tones remain. After which the resulting image

save again in a file with a .bmp extension and with 256-color grayscale coding. In a program for working with graphics that has a histogram function (for example, Adobe Photoshop version 7.0 or higher), a .bmp file with 256-color coding of shades of gray is opened and a histogram of shades of gray is built using standard tools. In the program "Adobe Photoshop" version 9.0 for this there is a window "Histogram" (Histogram). Figure 2 shows examples of the investigated card and the constructed histogram. The spectrum of shades is divided into 3 areas. The first area shows the number of shades at the 0th level (on a 256-color scale of shades of gray histogram) and reflects the content of black color (on the card this part corresponds to the area covered by the working fluid). It is in the leftmost position on the histogram scale. The second area shows the number of shades at the 255th level (on a 256-color scale of shades of gray histogram) and gives information about the content of shades of white color (on the card this part corresponds to the area uncovered by the working fluid). It is in the extreme right position on the histogram scale. The first and second areas on the histogram are distinguished on the basis of the lack of shades of gray in the transitional part (in the range of levels from 1 to 254 (on the 256-color scale of shades of gray histogram)). The middle transition on the histogram corresponds to the reflection of the content of various shades of gray. However, according to the above method of preparing a black and white image, the content of shades of gray in the transition region is absent.

At the last stage, the percentage of color in the region of interest of the histogram is determined. The area reflecting the black content is highlighted on the histogram (in the leftmost position on the histogram scale, the number of shades is at the 0th level on the 256-color scale of the histogram shades of gray), while the Percentile line (Percentages for the Adobe Photoshop program) displays information by

percentage of shades of black over the entire image area. This value (in the example shown in Figure 40.83%) corresponds to the degree of coverage of the card with the solution due to processing. In the graphical editor, the accuracy of calculating the hue content on the histogram is 0.01%, which allows to increase the accuracy in comparison with manual processing according to OST 10 6.1-2000.

The proposed bench for testing spray guns and the method of processing the results allows you to increase the number of investigated characteristics that evaluate the quality of the sprayer, selecting modes depending on the type of sprayer, an order of magnitude shorten the time for processing cards and obtaining results. This ensures the completeness of the study of various types of nebulizers, and reduces labor costs.

Literature

1. AS No. Golotutsky V.I. Stand for testing and calibrating spray guns: A.S. No. 41149 (RF) // B.I. 2004. No. 28.

2. Golotutsky V.I. The results of comparative tests of field sprayers. In: Agroecological Optimization of Agriculture. - Kursk: VNIIZ and ZPE, 2004. - P.257-259.

Claims (1)

Test bench for spraying crops sprayers, consisting of an electric drive, means for supplying and regulating the pressure of the working fluid, means for distributing the working fluid through the spray boom located above the classifier table to take into account the flow rate and uniform distribution of the width of the spray of the working fluid, exhaust system fluid supply, characterized in that it is equipped with a centrifugal fan with a guided air flow mounted on the frame of the stand and a clamp connected to the remote control, and a flatbed scanner for the discrete-density image pickup spray in black and white spectrum and passing it to a computer for further processing.