EVALUATION REPORT ON A DRIPPER LINE CLEANING MACHINE

Transcription

1 0 EVALUATION REPORT ON A DRIPPER LINE CLEANING MACHINE A S van Niekerk 21/12/12

2 1 Evaluation Report on the Dripper Line Cleaning Machine 20 th December 2012 A S van Niekerk Introduction A machine that can be used to clean dripper lines was submitted for testing by the ARC-IAE s Hydrolabs by Mr Leon Lingnau. The operation of the machine will be explained with the aid of figure 1 which is a photograph of the machine. Figure 1: The dripper line cleaning machine It consists of two pulley systems with the stainless steel sound bath in between. Along and in the bottom of the sound bath (which is filled with water) is the ultrasound source. The high frequency causes oscillation of the water and dirt particles which causes micro areas of negative pressure, which when upheaved, has the same effect as cavitation in pumps and this loosens the dirt particles.

3 2 The pulley system on the left in the picture is motorised and this pulls the drip line through the sound bath at a specific and constant speed. The speed determines the contact time of the drip line in the sound bath and it is set such that a contact time of about 30s is achieved. This system is also connected to a pump that circulates water through the whole of the drip line during the cleaning process and the flow rate must be high enough to wash out the loosened dirt at the far end of the drip line. In practice drip lines are stored in rolls and such a roll can be mounted on the right hand side pulley system in the picture and the cleaned roll can be taken off the left hand side pulley system at completion of the cleaning process. The water from the clean drippers is collected underneath the pulley and circulated through the sound bath to prevent the water in the bath from heating up and it flows over to the right hand side pulley system from where it is circulated back into the drip line by the circulation pump. It is thus a closed recirculating system. The dirt from the drip lines accumulates in the reservoir in the bottom of the right hand side pulley system which must be cleaned out from time to time. During the tests though the drip lines were laid in big loops* on the lab floor and the far ends of the lines were connected to a flow meter to register the flow rate through the lines and from there the wash water was conveyed to the top deck of the right hand side pulley system where it would flow slowly over a wide area at the end of which it would drop into the reservoir underneath. The result is that the dirt that is washed out of the drip lines would settle out onto the deck where it can be visually observed. Figures 3, 4, 5 and 6 in the report show a number of these observations. *Large loops

4 3 Test method With the machine three rolls of dirty drippers from different areas where different water sources are used for irrigation, were supplied. From our own lab a fourth roll was also used to evaluate the cleaning machine. One hundred drippers of each were mounted on our dripper test bench that can accommodate ten lengths of ten drippers each and the discharge of each individual dripper was measured. After that the ten lengths were connected to form one long drip line and this line was fed into the cleaning machine. The ten lengths were then separated again and each dripper was placed in the exact position on the test bench where it was measured before and its discharge was measured again at the same pressure as before. These measurements were processed in different ways to see what the effect is of the cleaning of the lines by the machine. Graphically the results were processed into graphs and our standard test report format. The cleaning process of the machine cleans the dripper lines internally as well as externally and visually the cleaning effect is presented in the report with before and after photographs of the drippers and of cuts that expose the inside of the dripper lines. Test results Results of some technical measurements are shown in the following table: Description Speed at which the lines were cleaned Time to clean 100 drippers Contact time Minimum wash water flow rate Flow speed of wash water Result 3,34 m/min 20 min 19,8 sec* 400 l/h** 0,6 m/s*** Notes: *This can be increased by reducing the speed of the motorised pulley, but it was not evaluated in the test. (According to Mr Lingnau this is not critical because most of the cleaning takes place in the first few seconds of contact time). **This was the outflow from the dripper lines. (The capacity of the pump was more than this because it had also to cater for the water that was emitted by the 100 drippers on the lines). ***This was measured by dividing the wash water flow rate by the cross sectional area of the dripper line. (According to general irrigation norms this value should be at least 0,5 m/s).

5 4 In the next table a description is given of the drip lines that were used in the tests. Name Sample A Sample B Sample C Sample D Description Agriplas 2,35l/h dripper, Pontdrif, Limpopo River, Limpopo Province. Agriplas 2,47l/h dripper, Pietersburg, Boreholes, Limpopo Province. Ram 2,31l/h pressure compensated, Mooketsi, Koedoes River, Limpopo Province. First pressure compensated Agriplas dripper (4), 2,54l/h, Vredendal, Olifants River, Western Cape Province. Note: Samples A-C were supplied with the machine; Sample D was from our own lab, a left-over of previous tests that were done. Graphical presentation of results The following table gives the results of the tests (depending on the type of dripper an individual tolerance for blocked drippers was applied for each): Sample Number of Blocked Drippers CV Value Before After %Change Before After %Change Sample A ,82 2,49 64 Sample B ,57 2,85 73 Sample C ,82 9,02-2* Sample D ,92 7,76 40 *Note: A possible explanation for the fact that the CV got worse can be found in the fact that this is a pressure compensated dripper. These type of drippers are more susceptible to blocking and it is possible that dirt that was loosened by the cleaning process could have entered the drippers further down the line and this has caused new partial blockages. On the following pages graphs are shown of the individual discharges of the drippers before and after they were cleaned. Because of the fact that the dripper lines of sample A were still in a fairly good condition (CV = 6,8) the graph of its data was blown up and cannot be compared directly with the other graphs. Note that the drippers of sample D is of such a nature that if dirt gets trapped in them, their discharge would increase most of the time and not decrease as is normally found with drippers that block and in this case drippers with too high discharge were taken as blocked. After the graphs follow the test results in official test format and the CV s and other information can be seen in these reports.

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10 Discharge (l/h) 9 DISCHARGE AND CV TEST RESULTS ON Leon Agriplas Light ZZ2 Limpopo before Page: Report no: D12036 Date: November 2012 AVERAGE PRESSURE (P) AND DISCHARGE (Q) RELATIONSHIP FOR 100 DRIPPERS: Recommended working pressure: Pressure (kpa) 70 kpa Maximum recommended working pressure: kpa Discharge formula: Q = x P Pressure (kpa) Discharge (l/h) Test results for a sample size of 100 drippers: Test pressure (kpa) Average discharge (l/h) Coefficient of variation (%) Maximum discharge (l/h) Minimum discharge (l/h) Variation in discharge (%) Hydrolab Norms: CV-value: 0,1-2,5 2,6-5,0 5,1-7,5 7,6-10,0 More than 10 Classification: Excellent Good Fair Marginal Poor Rating: Average To determine the CV values in accordance with ISO standards, the 100 drippers tested simultaneously were divided into four groups of 25 drippers per group, and the tests repeated three times. Fair Test results for a sample size of 25 drippers in accordance with ISO standards: Av. Test pressure (kpa) Groups: Group1 Group2 Group3 Group4 Group1 Group2 Group3 Group4 Group1 Group2 Group3 Group4 All Average discharge (l/h) Coefficient of variation (%) Maximum discharge (l/h) Minimum discharge (l/h) Variation in discharge (%) ISO Norms: CV-value: 0,1-5,0 5,1-10,0 More than 10 Classification: Good Mediocre Poor Rating: Mediocre Water temperature: 23 o C ARC-INSTITUTE FOR AGRICULTURAL ENGINEERING LNR-INSTITUUT VIR LANDBOU-INGENIEURSWESE Private Bag X 519, Silverton, Tel. (012) Fax. (012)

11 Discharge (l/h) 10 DISCHARGE AND CV TEST RESULTS ON Leon Agriplas Light ZZ2 Limpopo after Page: Report no: D12041 Date: November 2012 AVERAGE PRESSURE (P) AND DISCHARGE (Q) RELATIONSHIP FOR 100 DRIPPERS: Recommended working pressure: Pressure (kpa) 70 kpa Maximum recommended working pressure: kpa Discharge formula: Q = x P Pressure (kpa) Discharge (l/h) Test results for a sample size of 100 drippers: Test pressure (kpa) Average discharge (l/h) Coefficient of variation (%) Maximum discharge (l/h) Minimum discharge (l/h) Variation in discharge (%) Hydrolab Norms: CV-value: 0,1-2,5 2,6-5,0 5,1-7,5 7,6-10,0 More than 10 Classification: Excellent Good Fair Marginal Poor Rating: Average Excellent To determine the CV values in accordance with ISO standards, the 100 drippers tested simultaneously were divided into four groups of 25 drippers per group, and the tests repeated three times. Test results for a sample size of 25 drippers in accordance with ISO standards: Av. Test pressure (kpa) Groups: Group1 Group2 Group3 Group4 Group1 Group2 Group3 Group4 Group1 Group2 Group3 Group4 All Average discharge (l/h) Coefficient of variation (%) Maximum discharge (l/h) Minimum discharge (l/h) Variation in discharge (%) ISO Norms: CV-value: 0,1-5,0 5,1-10,0 More than 10 Classification: Good Mediocre Poor Rating: Good Water temperature: 23 o C ARC-INSTITUTE FOR AGRICULTURAL ENGINEERING LNR-INSTITUUT VIR LANDBOU-INGENIEURSWESE Private Bag X 519, Silverton, Tel. (012) Fax. (012)

12 Discharge (l/h) 11 DISCHARGE AND CV TEST RESULTS ON Leon Agriplas Pietersburg Boorgate before Page: Report no: D12035 Date: November 2012 AVERAGE PRESSURE (P) AND DISCHARGE (Q) RELATIONSHIP FOR 100 DRIPPERS: Recommended working pressure: Pressure (kpa) 70 kpa Maximum recommended working pressure: kpa Discharge formula: Q = x P Pressure (kpa) Discharge (l/h) Test results for a sample size of 100 drippers: Test pressure (kpa) Average discharge (l/h) Coefficient of variation (%) Maximum discharge (l/h) Minimum discharge (l/h) Variation in discharge (%) Hydrolab Norms: CV-value: 0,1-2,5 2,6-5,0 5,1-7,5 7,6-10,0 More than 10 Classification: Excellent Good Fair Marginal Poor Rating: Average To determine the CV values in accordance with ISO standards, the 100 drippers tested simultaneously were divided into four groups of 25 drippers per group, and the tests repeated three times. Poor Test results for a sample size of 25 drippers in accordance with ISO standards: Av. Test pressure (kpa) Groups: Group1 Group2 Group3 Group4 Group1 Group2 Group3 Group4 Group1 Group2 Group3 Group4 All Average discharge (l/h) Coefficient of variation (%) Maximum discharge (l/h) Minimum discharge (l/h) Variation in discharge (%) ISO Norms: CV-value: 0,1-5,0 5,1-10,0 More than 10 Classification: Good Mediocre Poor Rating: Mediocre Water temperature: 23 o C ARC-INSTITUTE FOR AGRICULTURAL ENGINEERING LNR-INSTITUUT VIR LANDBOU-INGENIEURSWESE Private Bag X 519, Silverton, Tel. (012) Fax. (012)

13 Discharge (l/h) 12 DISCHARGE AND CV TEST RESULTS ON Leon Agriplas Pietersburg Boorgate after Page: Report no: D12040 Date: November 2012 AVERAGE PRESSURE (P) AND DISCHARGE (Q) RELATIONSHIP FOR 100 DRIPPERS: Recommended working pressure: Pressure (kpa) 70 kpa Maximum recommended working pressure: kpa Discharge formula: Q = x P Pressure (kpa) Discharge (l/h) Test results for a sample size of 100 drippers: Test pressure (kpa) Average discharge (l/h) Coefficient of variation (%) Maximum discharge (l/h) Minimum discharge (l/h) Variation in discharge (%) Hydrolab Norms: CV-value: 0,1-2,5 2,6-5,0 5,1-7,5 7,6-10,0 More than 10 Classification: Excellent Good Fair Marginal Poor Rating: Average To determine the CV values in accordance with ISO standards, the 100 drippers tested simultaneously were divided into four groups of 25 drippers per group, and the tests repeated three times. Good Test results for a sample size of 25 drippers in accordance with ISO standards: Av. Test pressure (kpa) Groups: Group1 Group2 Group3 Group4 Group1 Group2 Group3 Group4 Group1 Group2 Group3 Group4 All Average discharge (l/h) Coefficient of variation (%) Maximum discharge (l/h) Minimum discharge (l/h) Variation in discharge (%) ISO Norms: CV-value: 0,1-5,0 5,1-10,0 More than 10 Classification: Good Mediocre Poor Rating: Good Water temperature: 23 o C ARC-INSTITUTE FOR AGRICULTURAL ENGINEERING LNR-INSTITUUT VIR LANDBOU-INGENIEURSWESE Private Bag X 519, Silverton, Tel. (012) Fax. (012)

14 Discharge (l/h) 13 DISCHARGE AND CV TEST RESULTS ON Leon Ramdrip before Page: Report no: D12034 Date: November 2012 AVERAGE PRESSURE (P) AND DISCHARGE (Q) RELATIONSHIP FOR 100 DRIPPERS: Recommended 0 50 working pressure: kpa 450 Maximum recommended working Pressure pressure: (kpa) 100 kpa Discharge formula: Q = x P Pressure (kpa) Discharge (l/h) Test results for a sample size of 100 drippers: Test pressure (kpa) Average discharge (l/h) Coefficient of variation (%) Maximum discharge (l/h) Minimum discharge (l/h) Variation in discharge (%) Hydrolab Norms: CV-value: 0,1-2,5 2,6-5,0 5,1-7,5 7,6-10,0 More than 10 Classification: Excellent Good Fair Marginal Poor Rating: Average Marginal To determine the CV values in accordance with ISO standards, the 100 drippers tested simultaneously were divided into four groups of 25 drippers per group, and the tests repeated three times. Test results for a sample size of 25 drippers in accordance with ISO standards: Av. Test pressure (kpa) Groups: Group1 Group2 Group3 Group4 Group1 Group2 Group3 Group4 Group1 Group2 Group3 Group4 All Average discharge (l/h) Coefficient of variation (%) Maximum discharge (l/h) Minimum discharge (l/h) Variation in discharge (%) ISO Norms: CV-value: 0,1-5,0 5,1-10,0 More than 10 Classification: Good Mediocre Poor Rating: Mediocre Water temperature: 23 o C ARC-INSTITUTE FOR AGRICULTURAL ENGINEERING LNR-INSTITUUT VIR LANDBOU-INGENIEURSWESE Private Bag X 519, Silverton, Tel. (012) Fax. (012)

15 Discharge (l/h) 14 DISCHARGE AND CV TEST RESULTS ON Leon Ramdrip after Page: Report no: D12038 Date: November 2012 AVERAGE PRESSURE (P) AND DISCHARGE (Q) RELATIONSHIP FOR 100 DRIPPERS: Recommended 0 50 working pressure: kpa 450 Maximum recommended working Pressure pressure: (kpa) 100 kpa Discharge formula: Q = x P Pressure (kpa) Discharge (l/h) Test results for a sample size of 100 drippers: Test pressure (kpa) Average discharge (l/h) Coefficient of variation (%) Maximum discharge (l/h) Minimum discharge (l/h) Variation in discharge (%) Hydrolab Norms: CV-value: 0,1-2,5 2,6-5,0 5,1-7,5 7,6-10,0 More than 10 Classification: Excellent Good Fair Marginal Poor Rating: Average Marginal To determine the CV values in accordance with ISO standards, the 100 drippers tested simultaneously were divided into four groups of 25 drippers per group, and the tests repeated three times. Test results for a sample size of 25 drippers in accordance with ISO standards: Av. Test pressure (kpa) Groups: Group1 Group2 Group3 Group4 Group1 Group2 Group3 Group4 Group1 Group2 Group3 Group4 All Average discharge (l/h) Coefficient of variation (%) Maximum discharge (l/h) Minimum discharge (l/h) Variation in discharge (%) ISO Norms: CV-value: 0,1-5,0 5,1-10,0 More than 10 Classification: Good Mediocre Poor Rating: Mediocre Water temperature: 23 o C ARC-INSTITUTE FOR AGRICULTURAL ENGINEERING LNR-INSTITUUT VIR LANDBOU-INGENIEURSWESE Private Bag X 519, Silverton, Tel. (012) Fax. (012)

16 Discharge (l/h) 15 DISCHARGE AND CV TEST RESULTS ON Ed Venter unused before Page: Report no: D12033 Date: November 2012 AVERAGE PRESSURE (P) AND DISCHARGE (Q) RELATIONSHIP FOR 100 DRIPPERS: Recommended 0 50 working pressure: kpa 450 Maximum recommended working Pressure pressure: (kpa) 100 kpa Discharge formula: Q = x P Pressure (kpa) Discharge (l/h) Test results for a sample size of 100 drippers: Test pressure (kpa) Average discharge (l/h) Coefficient of variation (%) Maximum discharge (l/h) Minimum discharge (l/h) Variation in discharge (%) Hydrolab Norms: CV-value: 0,1-2,5 2,6-5,0 5,1-7,5 7,6-10,0 More than 10 Classification: Excellent Good Fair Marginal Poor Rating: Average To determine the CV values in accordance with ISO standards, the 100 drippers tested simultaneously were divided into four groups of 25 drippers per group, and the tests repeated three times. Poor Test results for a sample size of 25 drippers in accordance with ISO standards: Av. Test pressure (kpa) Groups: Group1 Group2 Group3 Group4 Group1 Group2 Group3 Group4 Group1 Group2 Group3 Group4 All Average discharge (l/h) Coefficient of variation (%) Maximum discharge (l/h) Minimum discharge (l/h) Variation in discharge (%) ISO Norms: CV-value: 0,1-5,0 5,1-10,0 More than 10 Classification: Good Mediocre Poor Rating: Poor Water temperature: 23 o C ARC-INSTITUTE FOR AGRICULTURAL ENGINEERING LNR-INSTITUUT VIR LANDBOU-INGENIEURSWESE Private Bag X 519, Silverton, Tel. (012) Fax. (012)

17 Discharge (l/h) 16 DISCHARGE AND CV TEST RESULTS ON Ed Venter unused after Page: Report no: D12037 Date: November 2012 AVERAGE PRESSURE (P) AND DISCHARGE (Q) RELATIONSHIP FOR 100 DRIPPERS: Recommended 0 50 working pressure: kpa 450 Maximum recommended working Pressure pressure: (kpa) 100 kpa Discharge formula: Q = x P Pressure (kpa) Discharge (l/h) Test results for a sample size of 100 drippers: Test pressure (kpa) Average discharge (l/h) Coefficient of variation (%) Maximum discharge (l/h) Minimum discharge (l/h) Variation in discharge (%) Hydrolab Norms: CV-value: 0,1-2,5 2,6-5,0 5,1-7,5 7,6-10,0 More than 10 Classification: Excellent Good Fair Marginal Poor Rating: Average Marginal To determine the CV values in accordance with ISO standards, the 100 drippers tested simultaneously were divided into four groups of 25 drippers per group, and the tests repeated three times. Test results for a sample size of 25 drippers in accordance with ISO standards: Av. Test pressure (kpa) Groups: Group1 Group2 Group3 Group4 Group1 Group2 Group3 Group4 Group1 Group2 Group3 Group4 All Average discharge (l/h) Coefficient of variation (%) Maximum discharge (l/h) Minimum discharge (l/h) Variation in discharge (%) ISO Norms: CV-value: 0,1-5,0 5,1-10,0 More than 10 Classification: Good Mediocre Poor Rating: Mediocre Water temperature: 23 o C ARC-INSTITUTE FOR AGRICULTURAL ENGINEERING LNR-INSTITUUT VIR LANDBOU-INGENIEURSWESE Private Bag X 519, Silverton, Tel. (012) Fax. (012)

18 17 Visual presentation of test results The photographs that follow were taken completely at random and the cuts were also made randomly. SAMPLE A Externally Internally Before After SAMPLE B Before After SAMPLE C Before After

19 18 SAMPLE D Externally Internally Before After Dirt that came from sample A Figure 3

20 19 Dirt that came from sample B (Figure 4) Dirt that came from sample C (Figure 5)

21 20 Dirt that came from sample D (Figure 6) IMPORTANT REMARKS AND CONCLUSION The actual purpose of the dripper line cleaning machine is not to reclaim dripper lines that are seriously dirty and blocked, but to be used as a preventive measure so that drip lines can stay new and not become like the samples that were used. The idea is that dripper lines be cleaned on a regular basis from the start and in that way a farmer can keep his drip irrigation system in top form. In practice it was found that the Ram dripper and other pressure compensated drippers are trickier to get completely clean and two to three cleaning cycles are usually necessary for this. Acknowledgement Photographs on page 17 by: