Improvements in the Manufacture of Salt and in Apparatus and Appliances Employed therein.
Year: 1889

page_text: Date of Application, 19th Jan., 1889
Complete Specification Left, 2nd Oct., 1889-Accepted, 16th Nov., 1889
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Salt and in Apparatus and
Appliances Employed therein.
I, OTTO ERNEST POHL Manufacturer of 7 Customhouse Arcade Liverpool County
of Lancashire do hereby declare the nature of this invention to be as follows:-
Two patents have been granted to me under similar titles viz. No. 1503 in 1873 and
No. 3116 in 1872 and these improvements relate to them. They are twofold.
1. As regards the construction by modifications of the 2 evaporation pans forming
one apparatus.
A. In combination with draining channels in the bottompan (being formed by
making the bottompan broader than the toppan with or without perforated partitions
inside at a convenient distance from the sides) I construct the toppan in such a
manner that its bottom is fixed not at the end of the side plates as hitherto but in their
imiddle or thereabouts so that the lower portion of the side plates reaches downwards
from the bottom of the pan into the brine thus forming an absolutely tight flue for the
fire or products of combustion. With ordinary pans I obtain the same object by
rivetting plates to their sides airtight & long enough to descend into the brine. Heat
nonconducting materials may be fixed outside the plate.
B. To stay the bottompan's long sides more effectively I drive piles in the ground
along said sides & tightly against them at oqual convenient distances, but high
enough to reach considerably above the toppan. These piles or bulks must be
arranged so, that 2 & 2 on opposite sides are facing each other. To their top ends
iron or wood beams are fastened reaching across the top pan, from which beans rods
go down supporting the bottom of the toppan over the brine in the bottom pan
without the aid of pillars. The ends of the rods are arranged at the beams with
screws & nuts or otherwise so as to allow to alter the position of the bottom of the
toppan & to contract or enlarge the flue space. These beams may be used at the
same time for fixing a roof on.
C. By boarding up the interstices between the piles or bulks along the bottompan
and keeping one doublepan apparatus at a good distance from the next one built in a
line, having the bottompans a good height & the hurdles for drawing the salt from
the toppans across the whole distance a warehouse is formed into which the salt from
the toppans may be conveniently dropped from the hurdles through a trap door, after
draining its brine into the bottom pan, without labour of wheeling.
D. It having been shown by practice that leakages from the top pan destroy the
arches of the ovens if the toppan is extended over the same and that the front of the
bottompan is soon destroyed by overflowing brine, if the ovens are built closely
against it, I separate the ovens from the pans in such a manner that I make the
toppan no longer than the bottompan in front or even shorter, taking care to make the
front side of said toppan higher than the other sides so that no brine may run into the
ovens during drawing of salt. Instead of the usual narrow angleiron of 37 in front of
the toppans, bottom angleiron of 1 foot & more is used so that the rivets are not
so closely together where the first heat strikes.
E. The front side of the bottompan I construct so that the same forms an obtuse
angle instead of a right angle with the bottom; the ovens being vertical an aperture
is formed lengthwise between ovens and pan, so that the pan's side may be painted
& preserved-at-libitum.
F. It having been proved that in constructing the flue against the back of the
bottompan the departing steam & acid creates rust very quickly I form the flue
above the side of said bottom pan as a timber box supported by the sides & back of
the toppan itself in such a manner that the departing products of combustion and

page_text: steam as soon as they leave the opening between the pans have to pass into it. Either
the toppan may be made a little shorter for this purpose or a suitable timber channel
constructed. This box may have the topboards slanting downwards from the middle
towards the pan's sides to ensure easy rising of the products of combustion & steam
into the wooden chimney which is to be erected in the middle of said box, caulked
painted or pitched inside, the heat need not exceed 250° F. therein with the size of
the flue being properly regulated.
The second part of the improvements relates to the ovens & has for object their
durability & the production of white salt in the bottom pan with avoidance of black
smoke.
A. The ovens are erected in front of the mouth of the double pan. Blocks of
fireclay or other heatresisting material (specially made for the purpose with round
boltholes ending in square holes to receive the body and square head of the bolts
deeply imbedded in the block the top of the hole being filled with fireclay) are fastened
all-along the side of the toppan level with the top of the mouth of the 2 pans. In a
similar manner the bottompan is treated. The blocks serve to form the connexion
between the ovens and pans in the following way: from the topblocks to the front
wall of the ovens one arch is erected crossways all along the pan just in the opposite
direction as shown in the former patents & to the bottomblocks the back wall of the
ovens is joined. Over these arches (properly stayed) a thick layer of ashes is put.
B. The ovens may be built with partitions but I prefer one fire all along, the
gratings only being separated though as close to each other as possible, each grating
being constructed in duplo with fire bars fixed top & bottom to square frames, the
middle frame holding a pivotting bar in its middle, which rests on erections in the
ground with each end, catch lock arrangements-provided to hold grates in position if
made heavier at one-end than the other one. If for the purpose of cleaning the
grating is revolved round its axis or pivotting bar the duplex grating which was
underneath is taking the place of the grating shortly ago fired on & the latter can
be cleaned at leisure from cinders, whilst fire is at once being raked upon the duplex
grating from the neighbouring gratings through rake holes at the sides, top or other-
wise conveniently arranged.
C. For firing I use a hopper formed by a second wall on the bed plate at a
convenient distance before the proper oven wall which both have apertures at the
bottom formed by arches or otherwise. In this way black fuel is always kept in
front of the fire on the bed plate & shoved up the grate as required. There are
platforms on top before the ovens on which the fuel is delivered & whence it is
dropped through apertures left in the brickwork of the hopper for the purpose, which
are closed by covers or doors same way as the holes in front.
OTTO ERNEST POHL,
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Salt and in Apparatus and
Appliances Employed therein.
I OTTO ERNEST POHL Manufacturer of 7 Customhouse Arcade Liverpool in the
County of Lancashire do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement:-
Two patents have been granted to me under similar titles viz. No. 1503's &
3116" and these improvements relate to them. They are twofold.
1. As regards the construction by modification of the two evaporating paus forming
one apparatus.
.
a. In combination with draining channels in the bottompan, being formed by
making the bottompan broader than the toppan with a perforated partition inside at
a convenient distance from sides. I construct the toppan in such a manner that its
bottom is fixed not at the end of the side plates as hitherto but in their middle or

page_text: thereabouts, so that the lower portions of the sideplates reach downward from the
bottom of the pan into the brine (of the bottompan) thus forming an absolutely tight
flue for the fire or products of combustion. With ordinary pans 1 obtain the same
object by rivetting plates to their sides airtight and long enough to descend into the
brine. Heat non conducting materials may be fixed outside.
B. To stay the bottompan's long sides more effectively I drive piles in the ground
along & tight against them at equal convenient distances from one another & high
enough to reach considerably above the toppan. These piles or balks must be
arranged so that two & two on opposite sides are facing each other. To their top
ends iron or wood beams are fastened reaching across the toppan, from which beams,
rods go down supporting the bottom of the toppan over the brine of the bottompan
without the aid of pillars. The ends of the rods are arranged at the beams by screws
& nuts or otherwise so as to allow to alter the position of the bottom of the toppan
& to contract or enlarge the flue space. These beams may be used at the same time
for fixing a roof on.
c. By hoarding up the interstices between the piles or balks along the bottompan &
keeping one double pan apparatus at a good distance from the next one built in a line,
having the bottom pans a good height & the arrangement of hurdles for drawing the
salt from the toppans across the whole distance so that thereby a warehouse is formed
into which the salt from the toppans may be conveniently dropped from the hurdles
through trapdoors after' draining its brine into the bottom pan without labour of
wheeling.
d. It having been shown by practice that leakages from the toppan destroy the
arches of the ovens if the toppan is extended over the same & that the front of the
bottompan is soon destroyed by overflowing brine if the ovens are built close against
it, I separate the ovens from the pans in such a manner that I make the toppan no
longer than the bottompan in front or even shorter, taking care to make the front side
of said toppan higher than the other side so that no brine may run into the ovens.
Instead of the usual narrow angle iron of 3%, in front of the toppan angleiron of 12" &
more is used so that the rivets are not so close together where the first heat strikes.
The front side of the bottom pan I construct so that the same forms an obtuse angle
instead of a right angle with the bottom; the ovens being vertical an aperture is
formed lengthwise between the ovens & pan so that the pau's side may be painted &
preserved at libitum.
e. It having been proved that in constructing the flue against the back of the
bottompan the departing steam and acid create rust very quickly I form the flue
above the side of said bottompan as a timber box, supported by the sides & back of the
toppan itself, in such a manner that the departing products of combustion & steam
rise into it as soon as they leave the opening between the pans. Either the toppan
may be made a little shorter for this purpose or a suitable timber channel constructed.
This box may have the topboards slanting downwards from the middle towards the
pan's sides to ensure easy rising of the products of combustion & steam into the
wooden chimney which is to be erected in the middle of said box, caulked & painted
or pitched inside, the beat need not exceed 250° F, therein with the size of the flue
being properly regulated.
II. The second part of the improvements relates to the ovens & has for object their
durability & the-production of white salt in the bottom pan, with avoidance of black
smoke.
A. The ovens are erected in front of the mouth of the double pan. Blocks of
fireclay or other heat resisting material specially made for the purpose with round
boltholes ending in square holes to receive the body & square heads of the bolts deeply
imbedded in the block, the top of the hole filled with fireclay are fastened all along
the side of the toppan, level with the top of the mouth of the pan. In a similar
manner the bottompan is treated. These blocks serve to form the connection with the
ovens & pans in the following way: from the topblocks to the front wall of the ovens
one arch is erected crossways all along the pan, just in the opposite direction to that

page_text: shown in the former patents & to the bottomblocks the back wall of the ovens is joined.
Over these arches properly stayed a thick layer of ashes is put.
B. The ovens may be built with partitions but I prefer one fire all along, the
gratings only be separated, though as close to each other as possible & each grating
being constructed in duplicate with firebars fixed top & bottom on square frames, the
middle space holding a pivotting bar in its middle which rests on erections in the
ground with each end, catch lock arrangements provided to hold grates in position if
made heavier at one side than the other one. If for the purpose of cleaning the grating
is revolved round its axis or pivotting bar the duplex grating which was underneath is
taking the place of the grating shortly ago fired on & the latter can be cleaned at
leisure from cinders whilst fire is at once being raked upon the duplex grating from
the neighbouring gratings through rake holes at the sides, top or otherwise
conveniently arranged.
C. For firing I use a hopper formed at a convenient distance by a second wall on
the bed plate before the proper oven wall which has apertures at the bottom-formed by
arches or otherwise. In this way black fuel is always kept in front of the fire on the
bed plate & shoved up the grate as required. There are platforms on the top before
the ovens on which the fuel is delivered & whence it is dropped through apertures left
in the brickwork for the purpose & which are closed by covers or doors same way as
the holes in front. On the drawings; A is a vertical section of 2 double pans with
warehouse. B is a longitudinal section in 4 parts a, front of double pan with ovens
& grate b, showing one interior side of warehouse. c, showing full side of toppan lower
portion reaching into brine. d, arrangements of pans for escape of steam & products
of combustion with chimney. On A. 1. 1. 1. are draining channels with 2. 2. 2.
perforated partitions. By making these channels of half the pans width or therabouts
on each or either side of the pan, salt of a rough quality will be produced in such..
portions of the bottom pan. 3 are sideplates of top pans with 4, bottoms of toppans
fixed in their middle or therabouts so that side plates roach under brine lines. 5. 5.
space 6. 6. for heating gases coming from ovens. Arrangement for ordinary pans 7.
to attain same object; piles or balks 8. 8. to stay bottom pan's long sides. Iron or
wood crossbeams 9. 9. joining piles on top, rods 10. 10. 10 supporting bottom of
toppan fastened to crossbeams. Boardings 11. 11. on piles 8. 8. forming interior of
warehouse. 13 front view of which shows B. b. 11. Hurdles. 12 12 for drawing salt
from top pan with trapdoor 14. front toppan. 15 with lugh front side 17 to prevent
brine going on the ovens when brine is in motion during drawing of salt or otherwise.
Front side of bottom pan formning obtuse angle with bottom aperture. 18 between
bottom pan & ovens. Timber box flue 19. above pads with top 20 slanting both ways
towards chimney 21.
Second part. Ovens B. 22 fireclay blocks 23*, 23° fastened to top & bottom pan's
fronts with bolts 24. 24. 24. 24. arch 25. built from block 23ª & front wall 26 of
oven. To bottom blocks 23b the back wall of the ovens is joined stays 29. space for
ashes 28. duplicate revolver grate 30. The frame is formed by the grate bars
themselves being bent over at 31. & pivotting bar 32. erections on the ground 3. 3.
catchlock arrangements 34. in the wall which may be arranged in many ways the
hooks 35. 35. serving to break the grate loose by aid of a lever when wanted to
revolve & to fasten it by a pin 36. in front hopper 37. bed place 38. arched
aperture 39 in front wall over bed plate for admitting fuel; hopper formed by plate 40.
with slidedoor 41. to shut off coal when raking.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1. Making the long sides of the top pan to go lower than the bottom of said pan &
far enough to reach into the brine of the bottom pan thus forming between said bottom
& brine an airtight flue for the products of combustion & steam, the bottom pan of
course being made broader than the toppan.

page_text: 2. The perforated partitions in the bottom pan under the long sides of the toppan or
thereabouts by which draining channels or pockets are formed in the bottom pan
which when sufficiently extended beyond the sides of the toppan are utilized for
making rough salt though fine salt is being made in the bottom pan at same time &
common in the top pan all with the same fire.
3. The formation of a labour saving warehouse between, the long sides of the
bottom pans the hurdles serving as roof.
4. The arrangement of staying the sides of the bottompans by piles outside every
two opposite piles being joined on top by beams from which the top pan is being
suspended by rods.
5. The obtuse angle in front side of bottom pan to better preserve the same & the
high front side in top pan to prevent brine splashing on ovens.
6. Timber flue at back & on top of apparatus with rise towards chimney laterally &
longitudinally keeping top pan shorter than bottom pan.
7. The blocks of fireclay or other heat resisting material fastened to the front sides
of the top & bottom pan with bolts sunk into them which serve for connecting the
ovens to the pans.
8. The revolver grate consisting of a double row of firobars one above the other
fixed at a convenient distance either to frames or by bending the bars with a shaft
accross the middle (vortical to the bars) hanging on uprights in the ground, by which
means the grate can be turned upside down for the purpose of being cleaned whilst the
top side is being fired on at the same time thus avoiding cooling of the fire & black
smoke as a consequence.
9. The arrangement of the hopper for firing salt pans without smoke by a wall of
brick or iron on the bedplate in front (or hanging) of the oven wall which have each
holes to introduce a rake with which the coal is shoved in front of the firegrate to
enable which, the coal in the hopper is shut off by a slide door for the time being.
Liverpool, 1st October 1889..
OTTO ERNEST POHL.