Russian Journal of Applied Chemistry, 2011, Vol. 83, No. 6, pp. 1075−1079.
Pleiades Publishing, Ltd., 2010.
Original Russian Text
V.A. Chernikov, A.V. Chernikov, 2010, published in Khimicheskaya Promyshlennost’, 2010, Vol. 88, No. 1, pp. 1−5.
PROCESSES AND DEVICES
OF CHEMICAL MANUFACTURES
Washing of Sediment on Filtering Devices
V. A. Chernikov and A. V. Chernikov
“Scientiﬁ c and Production Company East Ukraine,” Kharkov, Ukraine
Received November 12, 2011
Abstract—Problems of ﬁ ltration washing of sediment are considered; the brief overview of the most common
ﬁ ltering devices is made; the particularities of the course of the washing process on these devices are considered.
It is stated that the optimal conditions for the effective and economic washing are provided by ﬁ lter presses with
vertical plates. The mechanism of the ﬂ ow of the washing liquid through the sediment on these ﬁ lters for two
versions, chamber and membrane ﬁ lter presses, is illustrated. The method of the objective control of the change in
the concentration of agent washed out from the sediment during the process of washing of sediment on mentioned
ﬁ lters with the help of the industrial conductivity meter is described.
The washing of ﬁ ltered sediment belongs to one of the
problems of chemical technology which is solved with
the help of ﬁ ltering devices.
The washing on ﬁ ltering devices is aimed at displacing
the pore water from the ﬁ ltered sediment. Therewith the
following tasks can be solved:
(1) Removal of harmful component of liquid phase
which is polluting the sediment. Examples can be the
manufacturing of pigment of titanium dioxide, colorants,
catalysts, “white carbon” etc., where salts in liquid phase
of the suspension pollute the sediment and spoil the qual-
ity of the ﬁ nal product.
(2) Displacement from the pore space of mother solu-
tion containing useful component. Examples can be the
manufacturing of potassium permanganate where the ﬁ l-
tered sediment in pore water contains a signiﬁ cant amount
of mother solution, and the unloading of unwashed or
not completely washed sediment leads to notable losses
of valuable components contained in the liquid phase of
In both cases the conﬂ ict of two factors takes place:
it is necessary to achieve the speciﬁ ed degree of dis-
placement of liquid phase of the initial suspension at
minimum consumption of washing liquid. The violation
of any of indicated limitations leads to economic losses,
e.g., increase in water consumption leads to necessity of
utilization of surplus amount of washing ﬁ ltrate, poor
water consumption leads to the increase in sediment of
the content of washed out component.
The character of the course of the ﬁ ltration washing
shows that in the initial period the displacement occurs at
high degree of efﬁ ciency (Fig. 1, washing of sediment at
production of “white carbon” on ﬁ lter press ChM 150);
but with the increase in the consumption of water the con-
tent of washed component in washing ﬁ ltrate decreases.
And in the end the process turns to some asymptote which
in each case has different concentration of the washed
The longer the ﬁ rst stage of washing is the less of
washing liquid for this purpose is needed. But the dura-
tion of this stage depends on the dispersive composition
of the solid phase, strength of the structure of sediment,
washing process conditions, and mainly on the particu-
larities of the equipment design on which such process
At the same time not all ﬁ ltering devices are able by
their design features to provide necessary efﬁ ciency of
the washing process. Thus, disc vacuum ﬁ lters as well
as belt ﬁ lter presses, cartridge and leaf ﬁ lters cannot be
applied to mentioned purposes.