How Albert Einstein and Leo Szilard Designed a Silent Refrigerator

A 1930 patent by Albert Einstein and Leo Szilard for a refrigerator that uses electromagnetic pumps instead of moving mechanical parts to circulate coolant.

What it covers

The patent describes an absorption refrigerator system that eliminates the need for moving parts like pistons or electric motors, which were prone to failure and leaks in early refrigeration technology. It uses an electromagnetic pump to circulate a refrigerant fluid through a closed loop. By leveraging the interaction between an electric current and a magnetic field, the system moves the liquid coolant without any mechanical wear, aiming for a design that is silent and durable.

What it doesn't cover

• —Does not cover standard vapor-compression refrigerators that use traditional electric compressors.
• —Does not cover refrigerators using chemical refrigerants like Freon or modern hydrofluorocarbons.
• —Does not cover systems that rely on mechanical pumps or rotating fans to move coolant.

The clever bit

The innovation lies in using an electromagnetic pump to move liquid metal or other fluids, completely removing the need for mechanical seals that were the primary point of failure for early home refrigerators.

Why it matters

This patent represents a rare intersection of theoretical physics and household appliance engineering. While the specific Einstein-Szilard design did not become a commercial standard due to the emergence of safer, more efficient compressor-based systems, it highlights the inventors' focus on solving the problem of toxic coolant leaks common in 1920s refrigerators.

Real-world examples

• 1.Experimental absorption refrigeration prototypes
• 2.Early silent cooling systems for laboratory use