Issues with the modification of the reducer for the 3W-A1 liquid ammonia pump
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I’d like to ask the experts! The 3W-A1 liquid ammonia pump used in our company’s urea production originally featured a two-stage planetary reducer; it has now been modified to use a hard-toothed cylindrical gear reducer. The rotational speed has increased from 112 to 148 rpm, while the discharge volume has risen from 20 to 26.4 m3/h. The inlet pressure is 1.7 MPa and the outlet pressure is 22 MPa. The efficiency of the pump is likely to be around 0.85–0.88. Question: What is the shaft power of the pump? Should a 315 model reducer or a 355 model reducer be chosen? The 315 reducer currently in use is performing very poorly (the gears are damaged and the bearings wear out quickly). After some calculations, it was determined that the nominal input power of this reducer is insufficient; therefore, a 355 reducer should be used. However, the manager said that a 315 reducer is sufficient, claiming that our maintenance work is of poor quality. I don’t have any experience, so I have to ask everyone to help me calculate it. I can’t express my gratitude enough; please do it. . . . . Additional notes: The pump plunger is 85 mm in diameter, it has three plungers, the stroke length is 200 mm, the medium used is liquid ammonia, and the pump has been in use for 20 years. The motor originally paired with it had a power rating of 160 kW. Currently, a 200–220kw motor is used, with a motor current of 330–360A. Environment: Small factory building, reducer with water-cooled coiled tubes; ambient temperature of 40°C; operates 24 hours a day, with no more than 5 startups per hour; continuous chemical production – downtime due to damage affects output. . . . Note: I don’t know what level the boss is at; I want to stick to my opinion, but I’m not sure about myself. . . I’m ashamed. Thank you again! This post was last edited by maya519 on 2009-4-28 00:53]
The 3W-A1 liquid ammonia pump used in our plant for urea production originally featured a two-stage planetary reducer; it has now been modified to use a hard-tooth surface cylindrical gear reducer. The rotational speed has increased from 112 to 118 rpm, while the discharge volume has risen from 20 to 21.4 m3/h. The inlet pressure is 1.7 MPa, and the outlet pressure is 22 MPa. The ZLYS355 YA reducer currently in use is functioning quite well (although there are issues with gear damage and short bearing life). The nominal input power of this reducer is insufficient; therefore, a 355 model reducer should be used. The motor has a power rating of 160 KW. Another pump of the same type also uses a 355 model reducer. The following are the main technical parameters and specifications for reference:
Model: 3JA-20/22-T (B170J1A-00)
Transported medium: Ammonium carbamate
Medium temperature: 90–100 °C
Inlet pressure: 1.7 MPa
Outlet pressure: 22 MPa
Flow rate: 6.7–20 m3/h
Pump speed: 35–105 revolutions per minute
Plunger diameter: 90 mm
Stroke length: 180 mm
Number of cylinders: 3
Oil type and quantity in the pump’s oil reservoir: Extreme pressure gear oil, grade 150; amount: approximately 125 liters
Motor model: YP315L1-4 (with axial fan)
Power: 160 KW
Voltage: 380 V
Rotational speed: 1485 revolutions per minute
Protection and insulation class: IP44, class F
Reducer model: ZLYS355-14-Ⅱ
Type: Hard-tooth surface cylindrical gear reducer
Gear ratio: 14.107:1
Oil type and quantity in the oil reservoir: Medium-grade gear oil, grade N220; amount: approximately 90 liters
Lubrication station model: RHZ.2/1.45-Ⅱ
Flow rate: 2
Motor power and voltage: 2.2 KW, 380 V
Explosion protection class: IP44, class F
Frequency converter model: FRN200G11S-4CX CIMR-G7A4185
Output power: 200 KW, 185 KW
Output current: 377 A, 370 A
Rated output voltage: 3Φ380V+10%-15%, 50Hz±5%
Yaskawa Electric Co., Ltd.
Cooling water consumption: 2 m3/h
Pump inlet diameter: Φ108×5 mm
Pump outlet diameter: Φ83×15 mm
Equipment dimensions (length×width×height): 5077×2378×1705 mm
Total equipment weight: 9209 kg
Model: 3JA-20/22-T (B170J1A-00)
Transported medium: Ammonium carbamate
Medium temperature: 90–100 °C
Inlet pressure: 1.7 MPa
Outlet pressure: 22 MPa
Flow rate: 6.7–20 m3/h
Pump speed: 35–105 revolutions per minute
Plunger diameter: 90 mm
Stroke length: 180 mm
Number of cylinders: 3
Oil type and quantity in the pump’s oil reservoir: Extreme pressure gear oil, grade 150; amount: approximately 125 liters
Motor model: YP315L1-4 (with axial fan)
Power: 160 KW
Voltage: 380 V
Rotational speed: 1485 revolutions per minute
Protection and insulation class: IP44, class F
Reducer model: ZLYS355-14-Ⅱ
Type: Hard-tooth surface cylindrical gear reducer
Gear ratio: 14.107:1
Oil type and quantity in the oil reservoir: Medium-grade gear oil, grade N220; amount: approximately 90 liters
Lubrication station model: RHZ.2/1.45-Ⅱ
Flow rate: 2
Motor power and voltage: 2.2 KW, 380 V
Explosion protection class: IP44, class F
Frequency converter model: FRN200G11S-4CX CIMR-G7A4185
Output power: 200 KW, 185 KW
Output current: 377 A, 370 A
Rated output voltage: 3Φ380V+10%-15%, 50Hz±5%
Yaskawa Electric Co., Ltd.
Cooling water consumption: 2 m3/h
Pump inlet diameter: Φ108×5 mm
Pump outlet diameter: Φ83×15 mm
Equipment dimensions (length×width×height): 5077×2378×1705 mm
Total equipment weight: 9209 kg