Open channel impeller centrifugal pumps – RE series

Open channel impeller centrifugal pumps – RE series

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Salvatore Robuschi RE pumps are multi-channel centrifugal pumps with an open channel impeller. Pumping solids suspensions, high viscosity liquids, low NPSHa values and high efficiency in difficult conditions – these pumps guarantee excellent suction performance even in the presence of dissolved gases and air. All pumps in this series have a single seal housing for all types of seals (single, tandem, cartridge, “back to back” or packed, according to API 682) and bearings designed according to ISO 5199.

RE series vortex pumps can be used for slightly contaminated liquids in sewage treatment plants, fertilizers, viscous liquids in the food or chemical industry, general industry, sugar, paper, steel, in refineries and power plants.

Salvatore Robuschi RE pumps are multi-channel centrifugal pumps with an open channel impeller. Pumping solids suspensions, high viscosity liquids, low NPSHa values and high efficiency in difficult conditions – these pumps guarantee excellent suction performance even in the presence of dissolved gases and air. All pumps in this series have a single seal housing for all types of seals (single, tandem, cartridge, “back to back” or packed, according to API 682) and bearings designed according to ISO 5199.

RE series vortex pumps can be used for slightly contaminated liquids in sewage treatment plants, fertilizers, viscous liquids in the food or chemical industry, general industry, sugar, paper, steel, in refineries and power plants.

Technical specifications
Pump capacity: up to 500 m3/h
Lifting height: up to 50 m
Maximum working pressure: 10 bar
Temperature: up to 220 °C – depending on the pumped medium
Discharge nozzle: from DN 80 to DN 125
Impeller type: open channel
Pump materialss: AISI 316 stainless steel, GJL250 cast iron
Optional: Superduplex, AISI 904L
Typical applications
Industry Application example
Food and sugar industry Sticky and viscous liquids
Wastewater treatment Wastewater suspensions with solid particles
Paper industry Pulp transfer up to 8%
Chemical industry Slightly contaminated media
Product features

Salvatore Robuschi RE are multi-channel centrifugal pumps with open impeller, equipped with bearings compliant with EN ISO 5199. Pumping of solid suspensions, high viscosity liquids, low NPSH values and high efficiency are the main features of this series, which can achieve excellent performance even in critical conditions. Seria ta może zagwarantować excellent performance even with liquids with a high content of dissolved gases and air.
The geometry of the blades has been designed to optimize the internal speed of the impeller, improving pump performance even in the case of viscous liquids and solid transfer.

RE series centrifugal pumps have a modular design that allows for reduced spare parts and storage costs. These pumps are designed in accordance with ISO 2858/5199 standards, making them interchangeable with other machines manufactured to these standards. All Salvatore Robuschi vortex series have one sealing housing for all types of seals – they can be equipped with single, tandem, cartridge, back to back or packing seals. Seals can be equipped with a PLAN according to API 682 (e.g. PLAN 11, PLAN 52, PLAN 53, PLAN 54).

  • Modularity and easy maintenance – 3 groups of bearing housings and shafts covering 10 different pump sizes. Oversized bases ensure high stability, and the design with a mounting flange avoids problems related to pump and motor misalignment.
  • Unified bearing housing – The same bearing housing can be used for pumps with closed, open, channel and vortex impellers. Design compliant with EN 25199, ensuring shaft deflection < 0.05 mm and min. 18,000 hours of operation, also designed to balance axial and radial loads and reduce operating temperature.
  • Performance – open multi-channel impellers made by lost wax casting for high hydraulic efficiencies and low NPSH values.
  • Open multi-channel impeller – the flow velocities at the inlet and outlet of the multi-channel impeller are very low compared to a traditional impeller, and the efficiency is close to that of closed impellers. Low speed also means low friction losses both on the suction side and when the liquid cuts through the blades, low NPSH, and higher efficiency when pumping viscous liquids. Multi-channel impellers are also suitable for pumping liquids containing solids, contaminated liquids, purees, concentrates, etc. Thanks to these features, these pumps can be used in many different applications and are suitable for many different installations.
  • Flexibility12 different sealing systems can be installed in one body cover.
  • Wide range of applications – transfer of slightly contaminated liquids in sewage treatment plants, pulp up to 8%, sugar industry, fertilizers, viscous liquids in evaporators of the food or chemical industry, refineries, general industrial services, food industry, seawater desalination plants, power plants, steel industry.
Operation principle

Operating principle of centrifugal pumps.The two main parts of a centrifugal pump are the impeller with blades (impeller) and the pump housing (casing). In the most common type – the centrifugal pump with a volute casing – the liquid enters the pump near the center of the high-speed rotating impeller. The liquid on the suction side moves along the axis of the impeller and due to the centrifugal force generated by the blades, it is thrown radially into the chamber in the casing. The casing gradually expands in a spiral manner towards the discharge nozzle, which reduces the velocity of the liquid and thus increases the pressure (diffuser effect). At the same time, as the liquid is thrown radially by the impeller due to centrifugal force, the pressure in the center of the impeller drops, enhancing the effect of drawing liquid into the pump, which enables a continuous liquid transfer process.

The impeller of a centrifugal pump is driven by a motor (most often electric) via a shaft. The pump head, along with the coupling and motor, constitutes the pump unit. In centrifugal pumps, gears are not used, and the rotational speed of the motor is transmitted directly. Most commonly, two- and four-pole motors are used (rotational speeds of approximately 2900 and 1450 rpm, respectively), and less frequently, six- and eight-pole motors are used (approximately 900 and 700 rpm).

A very important element of the pump is the seal at the point where the drive shaft enters the body. This seal is designed to prevent the pumped liquid from leaking out of the pump, maintain pressure inside the pump, and prevent air from entering the pump. Among the seals for centrifugal pumps, we can distinguish gland packing packings, single mechanical seals, and double mechanical seals. We also distinguish a special type of pump – sealless (hermetic) pumps.

Construction

Salvatore Robuschi RE Centrifugal Pump Construction

1. Reinforced bearing (ISO5199)
The bearing housing is standardized according to EN ISO 5199 and guarantees a shaft deflection of < 0.05 mm and at least 18,000 hours of operation. It is designed to optimize axial and radial pressures and drastically reduce operating temperature. All bearing housings are adapted for the use of a reinforced “HD” bearing version, which can operate for up to 100,000 working hours. The “HD” bearing is a combination of an angular contact bearing and a cylindrical roller bearing.

2. One casing, 12 sealing systems
For each pump size, a unique casing can accommodate any type, brand and seal selection. The dimensions of the seal chamber have been designed to guarantee effective and correct liquid circulation. By changing a few components, the sealing arrangement can be easily modified, making the pump ready for new plant or process requirements and reducing spare parts inventory.

3. One casing, two impellers
Each pump size can use a unique casing that applies to both closed (equipped with a wear ring) and open impellers (with a replaceable wear plate). This versatility allows the pump to be easily used in new installations and processes.

4. Wear plate and adjustment
The replaceable wear plate guarantees a long service life of the pump and reduces maintenance costs. In addition, the bearing housing is equipped with axial clearance adjustment, which is easily accessible from the drive side.

Design versions

 

REM

REL

REB

Salvatore Robuschi RDM Industrial Monoblock Centrifugal Pumps with Closed Impeller

Monoblock version with standard B5 electric motor.

Salvatore Robuschi RDL Close-Coupled Industrial Centrifugal Pumps

Version with independent support with bearings in oil bath and mounting flange for coupling with flanged motor. This version is available for motor sizes up to IEC 160.

Salvatore Robuschi RDB industrial centrifugal pumps with closed impeller and independent frame.

Shaft version: pump with independent oil or grease lubricated bearings, coupling (short or spacer), base and motor.

Types of seals

A cylindrical chamber built according to EN-12756 can be equipped with any type of mechanical seal.

Single mechanical seal in Salvatore Robuschi centrifugal pumps. Single mechanical seal

The most popular mechanical seals for use with non-contaminated liquids (no solids). The pumped liquid lubricates the sealing surface and dissipates heat.

Double mechanical seal in Salvatore Robuschi centrifugal pumps. Double back-to-back seal

A back-to-back double seal is a solution with a pressurized chamber. The external barrier fluid, supplied at a pressure approximately 0.5 – 1 bar higher than the pressure of the pumped medium, separates the product from the atmosphere.

Double tandem mechanical seal in Salvatore Robuschi centrifugal pumps. Double tandem mechanical seal

This type of seal has two pairs of face seals facing in the same direction. The use of this seal allows for a gradual reduction of pressure from the pump chamber or the use of a flushing medium and monitoring of the main mechanical seal of the product. The external service liquid reservoir serves to separate the pumped product from the atmosphere.

Cartridge mechanical seal in Salvatore Robuschi centrifugal pumps. Cartridge seal

A cartridge seal resembles a standard seal, but the stationary part of the cartridge seal is built into the housing, and the rotating part is mounted in a sleeve sealed with an O-ring. The cartridge seal housing is a mounting element in the pump, which eliminates the need to install a seal cover.

Packing seal in Salvatore Robuschi centrifugal pumps. packing seal

Packing seal is a special cord wound around the shaft separating the space between the pump body and the drive. It does not provide 100% tightness due to the need for continuous lubrication and cooling of the cords.

  • Technical specifications

  • Typical applications

  • Product features

  • Operation principle

  • Construction

  • Design versions

  • Types of seals

Pump capacity: up to 500 m3/h
Lifting height: up to 50 m
Maximum working pressure: 10 bar
Temperature: up to 220 °C – depending on the pumped medium
Discharge nozzle: from DN 80 to DN 125
Impeller type: open channel
Pump materialss: AISI 316 stainless steel, GJL250 cast iron
Optional: Superduplex, AISI 904L

Performance curves