1.1 Capability and purposeThe advantage of the pressed fishmeal production is handling material with high fat quantity in a short drying time. After the material is compressed, pressed juice in 2/3 quantity of the material comes out. There are still large amounts of fish protein water and nutrition in the pressed juice after we have reclaimed fish dregs and have refined fish oil. The concentrating system will process them to concentrated water and then fish meal (20%of the gross product).
We absorb both the domestic and the overseas advanced technology successfully to research the double concentrating system in NJ series with following characteristics:
1. It is in a vacuum hermetic condition when running. The water will be evaporated at more than 42ºC. It is an energy saving system for using the wastage from drier as heat resource. It is fit for all the drying and concentrating work.
2. It is also used for flowing work. If it compounds with the reflecting boiler, the fish paste products will be produced.
3. It deals with stick water during the process of fishmeal production and it will discharge distilled water and produce concentrated liquid without environmental pollution.
1.2 Basic structures and working principleThe concentrating system in NS series involves I & II effect evaporator, I&II effect separator, vacuum condenser and five pumps. It handles fish protein water to produce concentrated liquid through vacuum concentrating and forced cycling.
Evaporator: Its outer shell made of steel plate is a columnar shaped tube. Both its top and bottom have covers. On the top of the inner tube is the heat exchanging stainless steel pipes in lines while on the bottom is the liquid storing cavity. The material liquid is absorbed by pumps from the bottom of the liquid storing cavity and then is conveyed to the top of the evaporator and through screw injector, it goes to every pipes in lines equally and is flowing down along the inner wall of the pipes in the shape of film, at the same time, the film liquid will exchange heat with heating steam on the outer pipes, at last it is evaporated in vacuum condition. In this case, the material can be cycled to concentrate. The II evaporator will offer the material liquid to I evaporator and the heating steam in the outer pipe is wastage from drier. The material liquid used in the II evaporator comes form the exterior with the second steam form I evaporator as its heating steam. The vacuum degree in I evaporator is about 0.087Mpa while the II evaporator is 0.092Mpa.
The liquid and the gas separator: it is a columnar shaped tube. There is a conductor in it with arc square pipe connecting with the evaporator in the same vacuum. The liquid and the gas mixture flow from the pipes in lines of the Ievaporator, then goes to the liquid storing cavity and continues to cycle. The steam with little liquid goes to the separator. The separated liquid will counter flow to the evaporator through conducting pipes and the steam will be conducted to the II evaporator as the heat source through conducting pipes. The steam form the II evaporator after separated will go to the vacuum condenser by pipelines directly. Discharge the condensate.
Vacuum condenser: this is a columnar device installed at the height of more than 10 meters. There is a cooling water pipelines on the top of it and a falling water pipelines on the bottom. Its side connects with the liquid and the gas separator. Sufficient amount of cooling water goes to the condenser then equally falls through conducting plate to cool the second steam form the I&II evaporators, also with some part of not concreting steam flowing to the cycling cooling water pool. This system has both the advantages of condensing and taking out vacuum. The highest of the vacuum degree is up to 0.098Mpa.
Attentions: Make sure the temperature of the condensate is about 25ºC.