| 摘要 |
<p>The extracting agent, preferably sodium hydroxide solution containing 0.2 to 0.7 % of NaOH, is allowed to flow from bottom to top through a bed of the comminuted peat and is removed above the bed, at a rate such that the flow remains laminar and the extract obtained remains essentially free of entrained particles of the peat to be extracted. If appropriate, fresh extracting agent is added and the extracting agent is allowed to flow once more through the bed, preferably is recirculated several times. The apparatus for carrying out the process has at least one storage tank for the extracting agent (NaOH), at least one extraction tank (E) and at least one circulation tank (Z) for the extracting agent enriched with extract, feed pipes in which pumps (P) are arranged leading both from the storage tank (NaOH) and from the circulation tank (Z) into the lower pipe from each extraction tank (E), while the discharge pipe from each extraction tank (E) leads from its upper part and enters the associated circulation tank (Z).</p> |
