Iwaki EWN-R Series Electromagnetic Metering Pump

The Iwaki EWN-R series is an electromagnetic diaphragm metering pump with an integrated multifunction digital controller. It runs at up to 360 strokes per minute and sets the stroke rate in 1 spm steps, which gives repeatable dosing in continuous chemical feeding. Standard-type capacity reaches 420 mL/min, and special versions are available for gassing liquids, high pressure and high viscosity. Mikron Proses (Üsküdar, Istanbul) supplies Iwaki pumps in Turkey and provides application consulting on pump selection.

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The EWN-R shares its pump and drive platform with the EWN-Y series, which adds flow feedback control with an EFS flow sensor, and with the EWN-A series, which has an automatic air vent. For the wider range of Iwaki dosing pumps, see Iwaki chemical metering pumps.

Technical features and model family

The pump is built with a B (20 W) or C (24 W) drive unit and six effective diaphragm sizes (codes 09, 11, 16, 21, 31 and 36, from 8 to 35 mm). In the standard type, capacity rises from 38 mL/min (2.3 L/h) for the B11 to 420 mL/min (25.2 L/h) for the C36, and the rated discharge pressure falls from 1.0 MPa to 0.2 MPa with size. The B11 lists a maximum pressure of 1.4 MPa; the datasheet shows maximum pressure values in parentheses as limit values, not as rated values. The pump head is available in PVC (VC/VH), GFRPP (PC/PH), PVDF (FC/TC) or SUS316 (SH). The liquid temperature range is -10 to 40 °C for VC/VH and -10 to 60 °C for PC, PH, FC, SH and TC. The integrated controller reduces the sealing area, which gives an IP65 water- and dust-proof body, and the standard air vent valve lets gas in the pump head be released by hand.

Controller

In MAN mode the stroke rate is set directly (0.1-100 %). In EXT mode the pump follows DIV (divide) or MULT (multiply) pulse settings, or one of two analog modes: ANA.R, where 4-20, 0-20, 20-4 or 20-0 mA is proportional to the stroke rate, and ANA.V, a two-point variable setting. The 5-digit LCD can show the stroke rate in percent or the flow in mL/min or L/h.

Special versions

Besides the standard type there are three special versions. The high compression type (C) reduces the dead volume in the pump chamber to suit gassing liquids such as sodium hypochlorite or hydrogen peroxide. The high pressure type (H) handles up to 1.7 MPa (models B11 and C16), and the H2 type (model B11 only) up to 2.0 MPa, for injection into boiler feed lines. The high viscosity type (V) is intended for viscous liquids such as polymer flocculant in wastewater treatment. The right model depends on the chemical, the required flow and pressure, and the installation conditions.