IMPROVED PROCESS AND MACHINERY FOR SIFTING OR BOLTING
Year: 1885

page_text: I, HERBERT JOHN HADDAN, of 67 Strand, in the City of Westminster, Civil
Engineer, do hereby declare the nature of said Invention for IMPROVED PROCESS
AND MACHINERY FOR SIFTING OR BOLTING, a communication to me from abroad
by F. Winkler, Manufacturer, of Zschoppau, in the German Empire, to be as
follows:-
With the method of bolting pulverised materials, hitherto in use, almost
exclusively the principle of throwing the respective materials against a bolting
surface is applied. For this purpose various mechanisms have been constructed,
which however require generally a much higher mechanical force; than is in fact
necessary for the bolting process. Moreover the bolting process is not executed so
perfectly by these machines, as it is practically desirable.
The method hereafter described, differs entirely from the principles, heretofore
applied to the 'different bolting machines, by the throwing movement of the
material to be bolted being perfectly dispensed with and consequently the bolting
surface not only spared and always left open, but the whole bolting process effected
by using a proportionally little mechanical force.
The essential principle of the improved bolting process is the use of an air
current or the movement of a given air-volume, to conduct the parts to be bolted,
through the bolting surface or wall, whilst another air-current or body of air in
motion, acting in the contrary direction to the said current or body, opens again
the meshes of the bolter, which may be obstructed by the size or number of
particles of the material to be treated.
A body of air is applied, which is alternately pressed out from inside through
the bolting surface and subsequently sucked in again.
By this wave-like or alternate air current, produced in rapid succession, the
bolting process is effected by the aid of suitable contrivances.
The apparatus for carrying out this process, chiefly comprises a receptacle
provided with a bolting surface and containing an upright air pipe (either fixed or
rotary) adapted to impart to the air current such a direction, that it always
penetrates the bolting surface perpendicularly, the air current produced by suitable
mechanism, acting alternately by suction and by pressure.

page_text: The air current, produced by a revolving fan or beater and acting alternately by
pressure and by suction, may be directed perpendicularly to the stretched bolting
surface by means of a perforated partition along the inner or outer surface of which
the sifting material is guided and exposed to the bolting action.
The material to be bolted, is caused to pass along the bolting frame so as to be
exposed to the alternate air-current, whereby the light particles of the material are
pressed through the gauze and remain in the collecting receptacle, whilst the
suction air only serves the purpose of cleansing the obstructed openings of the
gauze. The sucking air-current is not of the same force as the pressing current,.
which difference may be regulated by an air suction valve. Instead of a simple
frame or partition a stationary or rotary cylinder may be used, in the middle of
which the air proceeds, instead of from a frame, from a stationary or revoluble
tube, provided with openings, and flows radially, that is to say rectangularly
through the bolting frame and thereby effects the bolting process.
In the case that the vibrating or alternately pressing and sucking air-current is
produced by the aid of a rapidly rotating fan, the wings must act so as to generate
alternately an air-current, pressing against the bolting frame, and.a suction current.
This may be obtained by suitably arranging or distributing the wings.
As however chiefly the tangential direction of the air currents, produced by
centrifugal force, must be changed into a radial direction, a partition similar to
venetian blinds, and furnished with openings, is used for this purpose.
This partition gives not only the air-currents an almost perpendicular motion
by the material falling down outside of the partition (Fig. 7) through the gauze
wall, but also produces a particular effect, chiefly coming forth, if the bolting
material is introduced into the bolting machine, inside the partition. In this latter
case the bolting material is subjected to a crushing effect, produced by the coarser
parts falling. on the surface of the partition. Therewith a crushing process is
executed in a manner, hitherto but known by theory, namely the particle of flour
is liberated by the crushing process, produced by means of the partition, and
subsequently prevented from any further crushing effect and submitted directly to
the bolting process.
The machine may be provided with a partition, the openings of which are
rendered adjustable by means of hinge-flaps, so as to be enabled to adapt the degree
of the grinding effect to the qualities of the material to be ground or bolted.
The bolting gauze must always be tightly attached to the frame to prevent the
same from being considerably moved by the suction and pressing air, as in the
latter case, the intended bolting effect would be anihilated and the liberating of
the meshes of the gauze would not take place. Further the partition resembling
a blind, serves as a means to change the tangential air-current into a radial
current.

page_text: Improved Process and Machinery for Sifting or Bolting.
I, HERBERT JOHN HADDAN, of 67 Strand, in the County of Middlesex, Civil
Engineer, do hereby declare the nature of this invention, a communication to me
from abroad by F. Winkler of Zschopau in the German Empire, and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
With the method of bolting pulverised materials, hitherto in use, usually the
principle of throwing the respective materials against a bolting surface is applied.
For this purpose various mechanisms have been constructed, which, however,
generally require a much higher mechanical force, than is absolutely necessary for
the bolting process. Moreover the bolting process is not executed so perfectly by
these machines, as it is desirable.
The method hereafter described differs entirely from those heretofore applied in
the different bolting machines, by the throwing movement of the material to be
bolted being perfectly dispensed with, and consequently the bolting surface not
only spared and always kept open, but the whole bolting process effected by using
a comparatively small mechanical force.
The essential principle of the improved bolting process is the use of an air
current or the movement of a given body of air, to conduct the materials to be
bolted, through the bolting surface or wall, whilst another air-current or body of
air in motion, acting in the contrary direction to the first current frees again the
meshes of the bolter, which may be obstructed by the size or number of particles
of the material to be treated. A body of air is applied, which is alternately
pressed out from inside through the bolting surface and subsequently sucked
in again.
The apparatus or contrivances represented by Figs. 1-14 of the accompanying
drawings, are arranged as follows:
The receptacle B, Figs. 1-7, contains the bolting frame B¹, tightly covered with
gauze or any other suitable web.
Through the tube D, arranged either stationary, as shown by Fig. 1, or movable
vertically with its nozzles, as shown by Figs. 2 and 3, a vibrating air-current is
introduced by means of a number of slits or other openings, which current is
produced by a pump-work or similar mechanism such as the bellows shown in
Fig. 6, and acts pressing and sucking in rapid succession on the bolting frame,
Figs. 1-7.
The material to be bolted is caused to pass along the bolting frame (Figs. 1-7)
so as to be exposed to the alternate air current whereby the light particles of the
material are pressed through the gauze and remain in the collecting receptacle C,
whilst the suction air only serves the purpose of cleansing the obstructed openings
of the gauze.
The sucking air current is not of the same force as the pressing air current,
which difference may be regulated by an air-suction valve. Instead of a simple

page_text: frame or partition a stationary or rotary cylinder (Figs. 4 and 5) may be used, in
the middle of which the air proceeds likewise from a stationary or revoluble
tube D, provided with openings and flows radially that is to say rectangularly
through the bolting frame and thereby effects the bolting process.
For producing alternately acting pressure- and suction-air currents, also a
swinging frame E, Fig. 7. may be arranged, which acts simultaneously on one or
two bolting frames B₁ by producing by rapid movement alternately pressing air
and suction air, which act upon the bolting frame.
In case the bolting process is intended to be effected by the aid of a rotating fan
work by using suction- and pressing air-currents; the fans must be arranged in
a particular manner, and a contrivance is required to change the tangential air
currents into radial currents.
The particular arrangement of the machine for this purpose is essentially as
follows:
If vertically arranged, (see Figs. 8 and 9), the fan-work is situated on a vertical
axle a in the interior of the partition A and the fans d are shaped as shown in
Fig. 9, so as to produce separate sucking air- and pressing air-currents, which,
flowing in rapid alternation, circulate in a wave like manner between the outer
periphery of the fan work and the air-space surrounding the bolting frame B¹, and
cause the bolting material to penetrate the bolting frame, the partition A having
the special effect of changing the tangential direction of the air-current and of the
bolting material into a radial direction to the bolting frame. As the air current
carrying the bolting particles is likewise radially changed by the partition system,
the bolting material may be introduced as well between the partition A and the
bolting frame B.
The partition A. consists substantially of a continuous grating, the bars of which
have a curved cross section as shown in Figures 5 and 9 or an angular cross section
as shown in Figure 14. These bars therefore form between them passages, which
are more or less curved or angular so that the currents of air passing through them
are deflected, and on issuing from the outer side of the partition A have a direction
substantially perpendicularly to the latter.
In the arrangement shown by Fig. 13, not only the fan-work d, but also the
partition frame A and the bolting frame B¹ are adapted to revolve. The direction
of the air currents and therefore of the particles of the material is indicated in the
drawings by arrows.
The impulsion is communicated through bevelled wheels h and pulleys i k l
The bolting material is introduced at m, passes between the partition A and the
bolting frame B¹ and leaves finally the machine at p.
Owing to the radial direction of the bolting particles and the great number of
rotations of the fan-work and therefore rapid succession of the suction- and
pressing-air-currents, the bolting effect, that is to say, the quantity of the bolting
material penetrating the bolting frame is of course considerably larger than by
throwing the bolting material directly by means of fans tangentially in slow
succession on the frame.
The fan work is constructed of unequal radial arms as shown in the drawing
and when rotating gives a wave-like motion to the air thereby giving alternate
suction and pressing-air currents in the neighbourhood of the bolting frame.
The fundamental forms of such fan constructions are shown by Figs. 9 to 12
and 14.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what
I claim is s
A bolting process and arrangement consisting in the bolting material being
alternately exposed to a pressing- and suction-air current while passing a bolting
frame, the pressing current driving the particles through the bolting openings or

page_text: meshes of the gauze, while the suction current frees any obstructed meshes, for
which purpose the requisite air currents' are produced:
a) by the arrangement of a blast acting alternately sucking and pressing and
consisting of a pump work, Fig. 6 and a nozzled distributing tube D, or swinging
frame E, Figs. 1 to 7.
b) by the action of a particularly constructed rotary fan d, Figs. 8 to 14,
surrounded by a stationary or rotary partition wall, which give the air currents
and the particles carried by the same, a movement in a direction radial to the
bolting frame, so that the material penetrates the bolting frame.
Dated this 3rd day of June 1886.
HERBERT JOHN HADDAN.
Pp. Herbert & Co., Agents.