农业工程学报
農業工程學報
농업공정학보
Transactions of the Chinese Society of Agricultural Engineering
2015年
19期
31-38
,共8页
陈忠加%俞国胜%王青宇%袁湘月%宁廷州%金实
陳忠加%俞國勝%王青宇%袁湘月%寧廷州%金實
진충가%유국성%왕청우%원상월%저정주%금실
生物质%设计%成型%致密成型%柱塞%平模%斜盘
生物質%設計%成型%緻密成型%柱塞%平模%斜盤
생물질%설계%성형%치밀성형%주새%평모%사반
biomass%design%briquetting%densification method%plunger%flat die%swash plate
针对传统生物质平模成型机能耗高、磨损严重的问题,该文提出了一种柱塞式平模生物质致密成型方法,并设计了成型机样机。该样机通过斜盘与弹簧配合,驱动柱塞往复运动,柱塞在运动过程中仅对模具内的原料进行挤压。成型模具部分采用组合式设计,主要由平模与成型套筒组成,可在成型套筒外部加热,同时可更换长径比不同的成型套筒以适应不同生物质原料。该文以不同颗粒度玉米秸秆和刺槐为原料,在原料含水率为15%,斜盘转速为50 r/min,原料温度为室温的条件下进行了试验,结果表明柱塞式平模生物质成型方法可行,颗粒成型率均高于98%,成型密度大于1.1 g/cm3,机械耐久性高于97%。该文提出的成型方法为生物质致密成型技术提供参考。
針對傳統生物質平模成型機能耗高、磨損嚴重的問題,該文提齣瞭一種柱塞式平模生物質緻密成型方法,併設計瞭成型機樣機。該樣機通過斜盤與彈簧配閤,驅動柱塞往複運動,柱塞在運動過程中僅對模具內的原料進行擠壓。成型模具部分採用組閤式設計,主要由平模與成型套筒組成,可在成型套筒外部加熱,同時可更換長徑比不同的成型套筒以適應不同生物質原料。該文以不同顆粒度玉米秸稈和刺槐為原料,在原料含水率為15%,斜盤轉速為50 r/min,原料溫度為室溫的條件下進行瞭試驗,結果錶明柱塞式平模生物質成型方法可行,顆粒成型率均高于98%,成型密度大于1.1 g/cm3,機械耐久性高于97%。該文提齣的成型方法為生物質緻密成型技術提供參攷。
침대전통생물질평모성형궤능모고、마손엄중적문제,해문제출료일충주새식평모생물질치밀성형방법,병설계료성형궤양궤。해양궤통과사반여탄황배합,구동주새왕복운동,주새재운동과정중부대모구내적원료진행제압。성형모구부분채용조합식설계,주요유평모여성형투통조성,가재성형투통외부가열,동시가경환장경비불동적성형투통이괄응불동생물질원료。해문이불동과립도옥미갈간화자괴위원료,재원료함수솔위15%,사반전속위50 r/min,원료온도위실온적조건하진행료시험,결과표명주새식평모생물질성형방법가행,과립성형솔균고우98%,성형밀도대우1.1 g/cm3,궤계내구성고우97%。해문제출적성형방법위생물질치밀성형기술제공삼고。
A flat ring die mill is frequently used for producing pellets. In the densification process, a great amount of energy is required to avoid spring back and to overcome the friction between the material and the channel surface of the die. However, extra energy is unnecessarily consumed because of friction between densified material and the pressure between the roller and the die, where there are no opening channels. The aim of this work was to attempt to eliminate a portion of the frictional and compaction energy based on an improving method of densification using a flat die. A new flat die pellet mill with plunger was developed. The self-developed flat die pellet mill mainly consisted of three parts: a flat die, plungers, and a swash plate. When the swash plate rotated, it drove the rolling bearing which was set up on one side of the plungers 16 mm in diameter to reciprocate along with the sliding bearing. The moment the plunger reached to the end position without the urge of swash plate, the return spring began to push the plunger back to the other end position. With the reciprocating motion of the plungers, the raw material under the plungers was compacted precisely only on the spot of the opening channel of the flat die to avoid compaction and friction that exists in the conventional flat die. Then the pellets were squeezed out through open end pelleting cylinders connected to the flat die. The pelleting cylinder was 16 mm in diameter and 80 mm in length, so the ratio of the length to the diameter of the pelleting cylinder was 5. The pelleting cylinders can be changed, then they can suit for different raw material. Moreover, each pelleting cylinder was wrapped by a heating tape with a thermocouple to preheat the cylinder die to a certain temperature when necessary controlled by a temperature controller and monitor. A series of experiments on its feasibility were carried out at ambient temperature. Corn straw and acacia were used as the experimental material. Corn straw was milled into fibrous pieces at three levels of particle size (0-2, >2-4, and >4-6 mm) with moisture content of 15%, while acacia was milled into fibrous pieces at three levels of particle size (0-3, >3-5, and >5-7 mm) with moisture content of 15%. The results demonstrated the pellet mill exhibited a good feasibility and capacity, which met preliminary requirements of pelletization. When working at the speed of 50 rpm, the molding rate in all the trials were above 98%. The productivity of using acacia was greater than that of using corn straw because of its higher bulk density. Furthermore, the density values of all the pellets were over 1.1 g/cm3, and the mechanical durability values of pellets were above 97%. After 4 weeks’ trials working, there were no obvious signs of wear on the plungers and the cylinder dies. The results above revealed the feasibility of the improving densification method, and the flat die pellet mill had the ability to produce the qualified pellets and to avoid the unnecessary wear and deformation on the flat die, which would be a new way for biomass densification technology.