粉体气力输送的基本形式(shi)(shi)有正(zheng)压(ya)输送(song)(song)(song)和(he)负压(ya)输送(song)(song)(song),主要(yao)分为负压(ya)稀(xi)相(xiang)输送(song)(song)(song)、正(zheng)压(ya)稀(xi)相(xiang)输送(song)(song)(song)、正(zheng)压(ya)密相(xiang)输送(song)(song)(song)、混合(he)式(shi)(shi)四(si)种(zhong)。根(gen)据(ju)料气比,有稀(xi)相(xiang)输送(song)(song)(song)和(he)密相(xiang)输送(song)(song)(song)之分(没有统(tong)一的分类标准)。虽(sui)然形式(shi)(shi)多种(zhong)多样,但都是(shi)在(zai)正(zheng)压(ya)输送(song)(song)(song)和(he)负压(ya)输送(song)(song)(song)的基础上发展起(qi)来(lai)的。
正压输(shu)送工作原(yuan)理:
1、进料(liao)(liao)阶段:进料(liao)(liao)阀和排气阀打开(kai),物(wu)料(liao)(liao)自(zi)由落(luo)入泵体内(nei)。当物(wu)料(liao)(liao)满时,料(liao)(liao)位计(ji)发出信(xin)号,进料(liao)(liao)阀和排气阀自(zi)动(dong)关(guan)闭,完成加料(liao)(liao)过程;
2、流化(hua)增(zeng)压阶段:打开(kai)进气(qi)阀,压缩(suo)空气(qi)进入泵(beng)体上下部分,上部增(zeng)压,下部空气(qi)扩(kuo)散穿(chuan)过流化(hua)床(chuang),使物(wu)料处于流化(hua)状态状态,同时(shi)泵(beng)内压力升高;
3、输送状(zhuang)态(tai):当泵内压力(li)达到(dao)一(yi)定值时,压力(li)表(biao)或压力(li)开关(guan)发出信号,卸料阀自动打开,流化床(chuang)(chuang)上的物(wu)料呈流化状(zhuang)态(tai),输送开始,床(chuang)(chuang)内物(wu)料被排(pai)出。泵逐渐减小。此时,流动在化学(xue)床(chuang)(chuang)上的物(wu)料始终处于流化输送状(zhuang)态(tai);
4、吹扫阶段:当泵内物料(liao)(liao)(liao)输送(song)完(wan)成(cheng),压力(li)下降到管道阻力(li)时(shi),压力(li)表或压力(li)开(kai)关发出信号,继(ji)续通(tong)气一定(ding)时(shi)间(jian),压缩空气对管道进(jin)行清洗,然后(hou)关闭进(jin)气阀(fa)(fa)。一段时(shi)间(jian)后(hou),出口(kou)阀(fa)(fa)门关闭。料(liao)(liao)(liao)阀(fa)(fa),打开(kai)进(jin)料(liao)(liao)(liao)阀(fa)(fa),完(wan)成(cheng)一个输送(song)循环。