NETZSCH NEMO BT Immersible Progressing Cavity Pump

Overview

The NETZSCH NEMO BT is a vertical immersible progressing cavity pump from NETZSCH for emptying and conveying media out of open or closed barrels, tanks, clarifiers, pits and similar containers. The conveying elements of the NETZSCH NEMO BT, rotor and stator, are fully immersed in the product, so no suction line is needed. NETZSCH points out that this makes the pump ideal where space is limited, where there is a danger of cavitation or the available NPSH is very low, and for very viscous products. Versions with a crane suspension bracket are also used to empty containers holding water-polluting or environmentally hazardous substances, where emptying through a bottom flange is not permitted. The NEMO brochure gives flow rates up to 310 m3/h, pressures up to 24 bar and immersion depths up to 10 m.

Seven Star LLC supplies the NETZSCH NEMO BT to wastewater plants, oil terminals, refineries, chemical plants and industrial sites in the Sultanate of Oman and across the GCC. Our Muscat engineers help define immersion depth, mounting style and materials for each tank or pit, and we provide model selection support from Muscat.

Operating Principle

The NETZSCH NEMO BT works on the progressing cavity principle: an eccentrically rotating helical rotor inside an elastic stator forms closed cavities that move the product steadily upward toward the discharge. Because the stator inlet sits in the liquid, the pump is flooded at all times and does not rely on suction lift, which is why it copes with highly viscous media and low NPSH conditions. Flow is low in pulsation and proportional to speed, so capacity can be adjusted in line with demand and the pump can also dose. NETZSCH notes that the NEMO BT is insensitive to sand in the medium, offers high pumping capacity and gives exact dosing accuracy.

Engineering Design of the NETZSCH NEMO BT

The pump uses the same proven core components as other NEMO industrial pumps. NETZSCH describes the rotor in wear- and corrosion-resistant designs, including the wear-free NEMO CERATEC ceramic rotor; a stator vulcanised into its tube with seals at both ends, available in elastomers, plastics and metals, with a hopper-shaped inlet that improves product feed; a coupling rod with two gimbal joints between drive and rotor; and a single-acting, bi-directional, wear-resistant mechanical seal as standard, with double seals, cartridge seals and packed glands on request. Connections follow DIN and international standards, in cast iron, steel, rubber-lined chrome-nickel steel or special materials.

The drive of the NETZSCH NEMO BT is flanged directly to the pump lantern, giving compact dimensions, low weight and easy maintenance. The pump is installed using a mounting flange on a tank lid or with a hanging bracket for crane suspension. Depending on size, speed and immersion depth, an additional guide element secures the pump to the floor or wall of the container; because the pump centres and locks itself in the guide, it can be removed even when the container is full. Immersion depth is set for each application and can be extended by lengthening the pump housing, adding a suction pipe, or both.

Integral Mounting Plate Version

NETZSCH also publishes a flyer for the NETZSCH NEMO BT with integral mounting plate. This version has a horizontal discharge connection above the mounting plate, or a compact design with vertical discharge through the plate, and immersion depths up to 33 ft (10 m) depending on size and speed. The flyer lists flow rates up to 616 gpm (140 m3/h) at pressures up to 360 psi (24 bar), with special designs up to 1,000 psi (68 bar). Self-centring bottom and wall guide supports hold the pump suction without clamps or bolts, and a heated double jacket design is available. The flyer table gives, for example, a maximum particle size of 2.0 mm for NM015 BT and 12.5 mm for NM063 BT.

Key Features

Features of the NETZSCH NEMO BT immersible pump include:

• Fully immersed rotor and stator, so no suction pipeline is required and low NPSH conditions are handled well.
• Operation at high conveying pressures, up to 24 bar, and high capacities up to 310 m3/h.
• Mounting flange, integral mounting plate or crane suspension bracket.
• Immersion depth up to 10 m, adapted to each container.
• Self-centring guide elements that allow removal from a full tank.
• Four rotor/stator geometries for optimum performance in each application.
• Proportional, adjustable capacity and precise dosing.
• Robust construction and sustainable design for low life cycle costs.

Industrial Applications

NETZSCH lists environment and energy, chemical, pulp and paper, and oil and gas mid- and downstream as typical fields for the NETZSCH NEMO BT. In Oman and the GCC, the pump is a good fit for emptying sludge pits and sumps in sewage treatment plants, lifting oily water and slops from interceptor pits and drain tanks at refineries and terminals, transferring viscous crude, bitumen or resins from storage tanks, unloading chemical containers from the top, and emptying underground tanks where bottom outlets are not allowed.

Seven Star LLC supplies the NETZSCH NEMO BT with the required immersion length, guide supports and spare parts to customers in Muscat, Sohar, Duqm and Salalah and throughout the GCC.

Technical Specifications

Performance data for the NETZSCH NEMO BT from the NETZSCH product page (further sizes and data on request):

How to Order

To get a quotation for the NETZSCH NEMO BT, send Seven Star LLC the medium, viscosity, solids, temperature, flow rate, discharge pressure, container depth and mounting arrangement. The NETZSCH brochure and the NEMO BT flyer are available for download on this page. Related pumps on our site include the NETZSCH NEMO BY NM038BY progressive cavity pump, the Sulzer ABS Piranha submersible grinder pump and the Weir Minerals Warman AH slurry pump. Seven Star LLC provides model selection support from Muscat for customers in Oman and the GCC.