Vertical motors for fresh drinking water
An exciting project is nearing completion for the VEM Group. After 13 months of construction, motors for a new drinking water plant will soon be delivered. The work was not always easy for everyone involved.
New waterways for Israel
The customer, Solcon Industries Ltd., was looking for motors for the construction of a new drinking water plant on behalf of the Israeli state water company Mekorot. The motors were needed to drive the pumps and to supply the population with drinking water. For this order, seven identical motors and the associated hydrostatic units were ordered from the VEM Group. Above all, the customer hoped for fast, high-quality and punctual delivery of the products, as well as of the necessary additional aggregates from VEM.
Jerusalem's challenge
For years, the population figures in Israel have been increasing. Because of this, the country is reaching the limits of the water resources currently available. The construction of new water supply routes has been on the way since the 1990s and will soon reach a new stage of expansion. The resulting pipeline is about 40 kilometres long and has a diameter of between 2 and > 2.50 metres. The future water plant will be fed from underground springs and, for the most part, from seawater, which is previously treated in desalination plants on the Mediterranean coast. Therefore, the entire pipeline system must be pressurised to between 20 and 40 bar and supported by pump stations at every 200 to 250 metres of elevation change. In this way, the water reaches Jerusalem, which lies 860 metres above sea level.
Vertical motors and special constructions
A special feature of the motors is their alignment. In contrast to conventional products, these are set up vertically and have a large support bearing which must hold not only the rotor but also the pump impeller underneath under full load. In addition to the considerable load capacity in the actual direction of rotation, the bearing must also be capable of running backwards at 125% of the rated speed. It is just this special feature of the motor which helps to prevent excessive wear of the bearing due to reverse rotation in the event of water return.
The motor thus has the following technical data:
| Type of construction | Power (kW) | Voltage (V) | Rated speed (rpm) | Type of construction | Cooling | Maximum downward thrust |
|---|---|---|---|---|---|---|
| IP55 | 4,700 | 11,000 | 1,000 | IM3011 | IC 81 W7 | 45 t |
Local content as part of the order
Israel requires the provision of Local Content when contracts are awarded by the state. Local Content supports the local economy, for example, by using products and services from the region or by providing resources for research and development. For the VEM Group, acceptance of the order was a big step towards the flourishing Israeli market. Contributing to the regional value chain was an unusual challenge that VEM successfully met by, among other things, training Israeli workers. In July 2021, for example, our Dresden site welcomed some Israeli workers to the plant, who were trained in the construction of the motors.
The collaboration was a time of learning and success for both parties, even though VEM was not able to fully exploit all facets of Local Content due to the Covid19 pandemic. Originally, the majority of the motors were to be delivered in "kit form", so that the rotor, radiator cowling and main terminal box would have had to be assembled on site by Israeli colleagues. Due to the vertical alignment of the motors, good technical knowledge is not the only thing that is required. The technical prerequisites in the form of crane capacities must also be met in order to be able to attach the bearing to the motor, which weighs about 20 tonnes.
Due to the difficult delivery situation, VEM, together with Mekorot, finally decided to provide all motors in assembled condition. Nevertheless, the Local Content project was an exciting and instructive experience for the VEM Group with many challenges and successes.
New technologies for production
Coil production is undoubtedly a very important step in the manufacture of a motor. The so-called glow protection tape - an insulation of the copper rod bent for the coil - has to be wound at precise and even intervals, which is why this time-consuming work is still mainly carried out by hand today. In this way, optimum functionality can be guaranteed. In the project for the new drinking water plant, robots were also used on the premises of the VEM Sachsenwerk. These special machines not only wind the tape at regular intervals, but they can also tie it around the curved parts of the copper rod with the utmost precision. In the production of seven identical motors, this option was a great time-saver for the VEM Group and helped to keep us on schedule.
VEM masters all challenges
The project with Solcon Industries Ltd. and Mekorot was one of the most complex for the VEM Group to date. Many different parties had to be involved in the planning. In addition, the commitment to create Local Content was a first for the company. Moreover, the production of six motors as a kit was not a routine task, despite years of expertise. VEM was nevertheless able to provide excellent support to all departments, external partners, clients and end customers, and to respond to each one's individual needs. Fluctuations in raw material prices and lack of transport capacity due to Covid19 also put severe cost pressure on the company and the project. Despite all the obstacles, VEM has been able to successfully meet all deadlines and cost agreements to date and deliver the usual high quality to the satisfaction of the customer.
Completion and delivery
Negotiations for the project started back in 2018 with a rough cost breakdown for the capital goods. Delivery of the motors is scheduled to take place by mid-August 2021, with a project review by the customer expected by the end of 2021. VEM is confident that the good business relations, high quality and excellent customer service will lead to further cooperation. With the help of the VEM motors, 65,000 cubic metres of water per hour can be fed into the drinking water supply at the last pumping station. With an average of 18 hours of pumping time per day, an additional 1.17 million cubic metres can so be pumped to Jerusalem and the surrounding towns in the future. About 2.5 million people will benefit from the new waterways over the next few years.