Fiber board production method free of sewage discharge

Abstract

The invention provides a fiber board production method free of sewage discharge. The method includes technical steps of (1) water cleaning of wood chips and impurity separation; (2) temperature rise treatment of the wood chips; (3) regular water replenishment of a water cleaning system. According to the invention, fiber board front-segment production procedures are optimized. A method of heating the wood chips indirectly instead of preheating the wood chips with water steam is adopted during a pre-stewing process, so that sewage generation caused by that excessive organic material in the wood chip dissolves in hot water (condensed water of steam) is avoided. Sewage generation is prevented during the whole production process. No sewage treatment device is needed and only regular replenishment of fresh water is needed. The mechanical property and appearance quality of boards produced by adopting the method are not distinctively different from those of boards produced by adopting a conventional method. In a case of a fiber board factory with an annual yield of 100 thousand cubic meters, treatment of 264 thousand tons of sewage is saved each year and the economic benefit is over 4,600,000 yuan. The method provided by the invention has deep practical meaning to ecological production of fiber boards.

Description

technical field [0001] The invention relates to a production method of dry-process fiberboard with zero sewage discharge, which belongs to the technical field of wood-based panel manufacturing in the wood industry. Background technique [0002] In the fiberboard production process, during the production, stacking, transportation and loading and unloading of wood chips, some stones, sand, and even metals are often mixed with sundries that are unfavorable to the heat grinding process. When the wood chips are used as raw materials for production, it is necessary to wash the wood chips in order to remove the metal, stone and sand mixed in the wood chips before the wood chips enter the thermal grinding process, so as to protect important equipment such as thermal grinders. Wood chip washing also has the following effects: (1) reduce the wear of mechanical equipment, such as reducing the wear of the feeding screw of the heat refiner; (2) improve the fiber quality. This is because...

AI Technical Summary

Problems solved by technology

At present, the wastewater treatment measures provided by most manufacturers are only sedimentation and slag removal for preliminary treatment of wastewater, which cannot meet the requirements of discharge standards.

Therefore, some manufacturers can only send waste water and wood chips into the cooking tank, and finally dry it through flue gas, and consume heat energy to heat the waste water into water vapor and discharge it outward.