The Heilonjian Boiler Factory had made model change as many as 7 times during 20years up to now to solve the said problem in order to fit this Internal Chain Stoker Boiler good for the coal of alal provinces of China (same as Indonesia). Firstly, they modified from wet back design to dried back in order to give longer space for the chain stoker extended to the back portion of the boiler shell so that the chain stoker will have enough time for the finish burning process. Thus unburn coal dropping at the end of the chain stoker was solved.
Ang Heilonjian Boiler Factory ay gumawa ng mga pagbabago sa modelo mahigit 7 beses sa 20 taon, at nasolusyonan na ang problema upang umandar ang Internal Chain Stoker Boiler na ito para sa uling sa mga probinsya ng Tsina, na may uling tulad ng sa Indonesia. Una, pinalitan ang wet back design sa dried back para magkaroon ng mahabang espasyo para sa chain stoker, na pinahabaan sa likod ng boiler shell para may sapat na oras na masunog ang uling.