Tank for pressure measuring cells in geotechnical applications

New and innovative aspects

The proposed solution focuses on solving the technical problem of configuring a device so that it is simpler and less expensive than known metal tanks. The technology developed is characterized by the use of a thermoplastic material for the manufacture of small tanks. This material allows the use of common techniques for the manufacture of parts with thermoplastic material, such as manufacturing by adding material or 3D printing or rotational molding, so the cost per piece is lower. In addition, it is possible to develop special total pressure cells, specific for specific solutions.

Main advantages of its use

• Thermoplastic polyurethane presents mechanical resistance combined with some flexibility and chemical resistance to oils.
• It is possible to improve the impermeability with a sheet of waterproof latex material or similar.
• Diameter between 30 mm and 150 mm, less than that of known tanks that usually start at a minimum diameter of 200 mm.
• Maximum height between 5 mm and 30 mm.
• Cheaper manufacturing process by using a thermoplastic material.
• It is easier and cheaper to develop special total pressure cells, specific for specific solutions, without a significant cost increase.

Specifications

A total pressure cell (or simply pressure cell) is device with a sensor that allows to measure compression pressures inside a material in a specific direction. It is commonly used to know the compression pressures that are exerted at a point inside the ground or the final linings in tunnels. The device includes a tank. There is a direct relationship between reservoir size and pressure measurement accuracy, the smaller a total pressure cell the more accurate it will be. The traditional manufacturing process of the metal tank is laborious, which makes the final product more expensive. In addition, the demand for this type of sensors is low and consequently, its manufacturing process is poorly mechanized.

The technical problem to be solved is to configure the deposit to be simpler and less expensive than known metal deposits. The material used is a thermoplastic polyurethane, suitable for this type of application, due to its mechanical resistance combined with certain flexibility and chemical resistance to oils. The diameter and height of the tank, and the thickness of the walls, are considerably lower than those of known metal tanks. There is the option of increasing the impermeability placing inside a sheet of waterproof latex or similar material.

Applications

Potential applications of the tank are as follow:

• In geotechnical instrumentation to know the compression pressures that are exerted at a point inside the ground in a certain direction or inside the final linings in tunnels, or between them and the ground.

Intellectual property status

Protected by utility model U202031698

Current development status

Device already developed and validated for industrialization.

Desired business relationship

Commercial Agreement, License Agreement, Technical Cooperation: further development; Technical Cooperation: testing new applications; Technical Cooperation: adaptation to specific needs.