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Original Hydro-Thermal Logo
Historic Image of Employees with a Hydroheater
1964 Hydro-Thermal Employee with Hydroheaters

History of Steam Innovation

Hydro-Thermal traces its roots back to 1927, when inventors John White and Roy Miller patented heating equipment using steam to precisely control water temperature. The device was “direct in action,” extended the service life and used a “valve seat with a sliding closure member”. These components continue to serve as a foundation for Hydro-Thermal's direct steam injection technology today.

Manufacturing industrialist, Harry Schauer brought this technology to paper mills in the early 1930s. Through collaboration with chief engineers from Kimberly-Clark, they applied the equipment to heat byproducts for cooking in digesters, recaustization, atomizing, and providing accurately controlled hot water. The heater became the heat catalyst in these chemical reactions and became known as the Hydroheater™, which was first manufactured in 1934.

In 1964 the Zaiser family purchased the business and renamed it Hydro-Thermal Corporation. Donald Zaiser operated the company at its Wauwatosa, Wisconsin location on 70th and State Street. Companies like ADM (Archer Daniels Midland), Cargill, Cerestar, Corn Products Company, and Grain Processing Corporation used the Hydroheater for integrated corn-based sugar production.

Gary Zaiser began the second generation of ownership in 1979. With his Mechanical Engineering degree from Cornell University, the company expanded applications to grain based ethanol at Andersons, Badger State Ethanol, Flint River, and VeraSun, and the chemical industry at Ashland Chemical, EI DuPont, PCS Phosphates, and PPG Industries. Hydro-Thermal grew in business, building its facilities in Waukesha, Wisconsin and grew in knowledge through university partnerships to generate fundamental research in steam heating.

Today, Jim Zaiser represents the third generation, leading the company’s product diversification, advanced two-phase flow realization, international expansion, and system integration. The company has continued its application to the traditional industries as well as new installations in petroleum, mining, and food processing.

The company has more than a dozen active patents and registration in numerous foreign countries. It manages business processes though an integrated ISO 9001 quality procedure. An on-site test lab allows engineers, researchers and academia to completely understand and develop new innovative and value-added processes. The company continues to invest in people, hiring the best and the brightest, and investing in the health and wellness of all employees.


To see our history timeline, click here.

To learn more about our technology, click here.

To learn more about our products, click here.

To contact us, click here.

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Hydro-Thermal is the global leader in the development and manufacturing of Hydroheaters. Through our vast global channel partners, we support hydro heating in six continents and all industrialized areas. We create heating systems for a variety of industries including: pulp, paper, chemical, ethanol, food & beverage, metal, & more!

Hydro-Thermal Corporation 

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