Vertical motors for fresh drinking water

An exciting project is about to be completed for the VEM Group. After 13 months of construction, engines for a new drinking water plant will soon be delivered. The work wasn't always easy for everyone involved.

New waterways for Israel

The customer Solcon Industries Ltd. was looking for engines 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 are intended to supply the population with drinking water. For this order, seven identical engines and the associated hydrostatic units were ordered from the VEM Group. Above all, the customer hoped that VEM would provide fast, high-quality and punctual delivery of the products and the necessary additional units.

Jerusalem's Challenge

The population numbers in Israel have been increasing for years. As a result, the country is reaching the limits of currently available water supplies. The construction of new water supply routes has been under discussion since the 1990s and will soon reach a new stage of expansion. The resulting pipeline is approximately 40 kilometers long and has a diameter between 2 and > 2.50 meters. The future water system will be fed from underground sources and largely from seawater, which is previously processed in desalination plants on the Mediterranean coast. Therefore, the entire pipeline system must be pressurized between 20 and 40 bar and supported by pump stations every 200 to 250 meters of height difference. The water thus reaches Jerusalem, which is 860 meters above sea level.

Vertical engines and special designs

A special feature of the motors is the alignment: Unlike conventional products, they are set up vertically and have a large support bearing, which not only has to hold 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 able to run backwards at 125% of the nominal speed. It is precisely this special feature of the motor that helps ensure that there is no excessive wear on the bearing due to the reverse rotation if water returns.

The engine therefore has the following technical data:

Technical data
Design	Power (kW)	Voltage (V)	Nominal speed (rpm)	Design	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. With local content, the local economy is supported, for example, by using products and services from the region or by providing resources for research and development. For the VEM Group, accepting the order was a big step towards the flourishing Israeli market. Contributing to the regional value chain was an unusual challenge that VEM was able to successfully overcome, among other things, by training Israeli workers. In July 2021, the Dresden site welcomed some Israeli colleagues to the factory who were instructed in building the engines.

The collaboration was a time of learning and success for both parties, even if VEM was not able to fully utilize all facets of the local content due to the Covid19 pandemic. Originally, the majority of the engines were to be delivered using a "modular principle", meaning that the rotor, radiator hood and main terminal box would have had to be assembled on site by Israeli colleagues. Due to the vertical orientation of the motors, not only good specialist knowledge is required. The technical possibilities in the form of crane capacity must also be available to attach the bearing to the engine, which weighs around 20 tons.

Due to the difficult delivery situation, VEM, together with Mekorot, ultimately decided to provide all motors in an assembled state. Nevertheless, the Local Content project was an exciting and educational experience for the VEM Group with many challenges and successes.

New technologies for production

Coil production is undoubtedly a very important step in the production of a motor. The so-called corona protection tape, an insulation of the copper rod bent for the coil, must be wound at precise and even intervals, which is why this time-consuming work is still carried out primarily by hand. In this way, optimal function can be guaranteed. In the project for the new drinking water plant, robots were also used on the site of the VEM Sachsenwerk. These special machines not only wrap the tape at regular intervals, they can also tie around the bent parts of the copper rod with the highest precision. When producing seven identical engines, this option saved a lot of time for the VEM Group and helped them stay 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 obligation to create local content was a first for the company. The production of six engines as a kit was also not an everyday occurrence, despite years of expertise. VEM was still able to provide excellent support to all departments, external partners, customers and end customers and to respond to everyone's individual needs. The price fluctuations of raw materials and a lack of transport capacity due to Covid19 also put severe cost pressure on the company and the order. Despite all the stumbling blocks, VEM has been able to successfully meet all deadlines and cost agreements to date and deliver the usual high quality to the customer's satisfaction.

Completion and delivery

Negotiations for the project started in 2018 with a rough cost breakdown for the capital goods. Delivery of the engines is scheduled to take place by mid-August 2021, and a project review by the customer is expected by the end of 2021. VEM is confident that the good business relationships, high quality and excellent customer service will lead to further cooperation. With the help of the VEM motors, 65,000 cubic meters of water per hour can be fed into the drinking water supply at the last pump station. With an average pumping time of 18 hours per day, an additional 1.17 million cubic meters can be pumped to Jerusalem and the surrounding cities in the future. Around 2.5 million people will benefit from the new waterways over the next few years.