The Indian inventor Dr. Milind V. Rane was a freelance consultant when he conceived and developed the design for the Matrix Heat Recovery Unit (MHRU). The invention relates to a heat exchanger. It can be used for recovering heat from hot gases and/or vapors from engines, gensets, boilers or furnaces. Heat is recovered in the form of steam, hot water or hot thermic fluid. The design was motivated by the need to develop a heat recovery unit to address certain limitations of the prior art, which were based on shell and tube configuration with gas or water tube designs.
The inventive step of the invention was the combination of at least two sets of heat transfer passages encapsulated in a conducting matrix, wherein one of the sets carries hot gases and the heat recovery fluid passes through the other set.
Dr. Rane’s invention was found to have various advantages over existing products, including the following:
- Simple design
- Low fouling
- Low gas side pressure drop
- High heat transfer coefficients
- Low fluid retention volumes
- Compact design
- High reliability
- Modular design
- Quick steaming
- Low cost (20 to 25% lower than that of conventional design)
|Figure 1 shows the installation of MHRU’s for steam generation, setup on two 1000 kVA Diesel Gensets. It can be seen that the size of the steam generator is smaller than the muffler of the Genset. Size of a conventional steam generator would have been larger than the engine.|
From Concept to Commercialization
Through a mutual friend, Dr. Rane was introduced to the General Manager of M/s Unidyne Energy Environment Systems Pvt Ltd., a small-scale industry based in Mumbai. Unidyne had engaged in the manufacturing and sale of direct and waste heat fired boilers and various industrial thermal energy systems for some time. Following a demonstration of the invention to the company, a Memorandum of Understanding (MOU) was signed with Unidyne by which a license was granted to Unidyne to manufacture and sell the MHRUs as engine exhaust fired steam generators and water and thermic heaters.
As per the MOU, a down payment was made at the time of signing and subsequent payments were made after achieving various milestones during the demonstration phases. The agreement stipulated a royalty rate of 4.5% of net sales for the inventor, and the costs of patent filing and maintenance are borne by the company. The patent was not assigned to the company but it was agreed that the technology would not be licensed to any other company in India as long as a minimum royalty payment schedule is met.
A provisional specification for MHRU was filed in India in 1999 after successful demonstration of the invention to the company. The first examination report was received from the Indian patent office in early 2004. The Patent Agent was changed mid course and the patent specification and claims had to be amended. After a hearing at the patent office and a few office actions with the patent examiner, the patent has been accepted on 12/10/2004. It is now awaiting publication in the Gazette of India. If there is no opposition, the patent will proceed to the grant stage. The invention was licensed on the basis of the patent application.
Marketing of the Invention
Currently, over 45 MHRUs have been installed in various companies in India. They are installed on engine gensets in the range of 165 kVA to 6 MVA fired with diesel, gas, furnace oil and biogas. Initially, MHRUs were marketed through the company’s existing network. Subsequently, an original equipment manufacturer (OEM) contract was signed with Cummins Diesel Sales and Services (CDSS).
MHRUs have been installed for the following applications:
- Water heating up to 90oC (un-pressurized) and up to 180oC (pressurized)
- Steam generation up to 20 bar
- Thermic fluid heating up to 330oC
- Furnace oil heating up to 130oC
Conclusions and Lessons Learnt
For Unidyne, the agreement represented an important move as it enabled it to enhance its product portfolio and widen its technology and customer base. For the inventor, the license provided a vehicle for the commercialization of the invention. Revenues generated from the down payment and the royalties have helped for the development of other inventions.
Since this was the inventor’s first exposure to the patent system, and due to lack of adequate initial guidance, the invention was only filed in India. The priority period lapsed without filing applications abroad. With hindsight, this proved to be a mistake, as the market for the MHRU extends beyond the national boundaries.
Amending the claims to the patent specification during the patent prosecution stage was an important step to be able to effectively protect the invention. Interactive sessions with the patent agent has also opened up new avenues and the inventor has now filed Indian as well as PCT applications for 12 other inventions, including:
- Energy efficient liquid desiccant regeneration (WO 03070356)
- Energy efficient absorption system (WO 03071197)
- Multi-utility vapor compression system (not yet published)
- Tube heat exchanger (WO 2004 051168)
- Freeze concentration system (WO 2004 045738)
- Energy efficient conditioning of air using liquid desiccant (WO 2004 081462).
Some of these are already in the process of being licensed for commercialization.