Slope-channelled, easily cleaned steep tank floor

A flat-surfaced steep tank floor has a "U" shaped primary channel which extends diametrically across the floor, and a plurality of "U" shaped secondary channels which extend transversely to and intersect the primary channel. The channels have perforated covers which can be controllably removed to facilitate cleaning. The primary channel slopes downwardly from one side of tank to the opposite side. Each secondary channel slopes downwardly from one side of the tank to the primary channel. The secondary channels are perforated at regular intervals. The tank is aerated via aeration conduits which extend beneath the floor and communicate with the perforations.

FIELD OF THE INVENTION 
This application pertains to a steep tank having a floor in which a 
plurality of sloped channels are formed to facilitate cleaning and 
aeration of the tank, as well as extraction of carbon dioxide therefrom. 
Each channel has a hinged, perforated cover which can be raised to expose 
the channels when the tank is cleaned. 
BACKGROUND OF THE INVENTION 
Steep tanks are used to produce malt which is in turn used to produce 
brewed alcoholic beverages such as beer. A modern industrial steep tank is 
typically a large volume cylinder which may be about 25 feet or more in 
height and about 50 feet or more in diameter. A mixture of barley kernels 
and water is "steeped" in the tank for a suitable interval, typically in 
the range of about 24 to 60 hours. Air is injected through the tank floor 
to aerate the barley-water mixture. Carbon dioxide given off by the steep 
mixture is withdrawn through the floor. 
Prior art steep tanks commonly employ a perforated steel false floor which 
is constructed above the bottom of the tank. The space between the false 
floor and the bottom of the tank typically contains piping, valves, etc. 
for draining water or carbon dioxide from the tank, injecting compressed 
air into the tank, etc. 
The steep tank's internal surfaces, including the underside of the false 
floor, the surfaces which define the space between the false floor and the 
bottom of the tank, and the surfaces of anything located within that 
space, become contaminated with bacteria, slime, etc. during the steeping 
process. All such surfaces must be cleaned periodically to remove such 
contamination. Preferably, such surfaces are cleaned after each batch of 
malt is produced. 
In earlier prior art designs, the false floor was fixed in place, making it 
very difficult to adequately clean the floor's underside and anything 
beneath the floor. The art has since evolved to provide a variety of false 
floor designs which are somewhat easier to clean. 
One prior art technique is to locate the false floor six feet or more above 
the bottom of the tank. Access panels are provided in the adjacent tank 
walls to enable workmen to enter the space between the false floor and the 
bottom of the tank in order to clean the underside of the floor, etc. with 
pressurized hoses. However, the space between the floor and the bottom of 
the tank is preferably made as small as possible since it becomes filled 
with water during the steeping process. Water is relatively expensive. The 
steeping process is not benefitted by water which fills the space between 
the floor and the bottom of the tank. 
The prior art accordingly evolved in an effort to minimize the space 
between the false floor and the bottom of the tank. This is typically 
accomplished by providing a mechanism for raising and lowering the false 
floor. The floor can thus be raised to a height sufficient to enable 
workmen to enter and clean the space beneath it. The floor is then 
lowered, leaving only a small space sufficient to contain aeration and 
drainage systems as aforesaid. 
Despite its advantages, the foregoing technique created some additional 
problems. For example, before the floor can be raised, it is first 
necessary to disconnect aeration, drainage, and other systems (which are 
coupled to the floor from outside the tank) and then reconnect them when 
the floor is lowered back into position. Further, it is difficult for 
workmen to adequately clean the underside of an elevated floor by working 
over their heads with high pressure hoses. Also, safety concerns 
complicate and increase the cost of the cleaning process. For example, 
regulations typically require provision of a secondary mechanism to hold 
the floor in its raised position while workmen are beneath it. Such 
regulations may also require that valves, electrical controls, etc. for 
equipment located in the space between the false floor and the bottom of 
the tank be locked out before workmen enter that space to begin cleaning. 
Some of the foregoing difficulties have been circumvented by further 
evolutions in the art. For example, the false floor is sometimes divided 
into sections, each of which is hinged to provide underfloor access. This 
avoids the cost and complexity of raising and lowering the floor for 
cleaning, but can require additional manual labour. In other cases, a 
"clean-in-place" system of conduits and nozzles is installed beneath the 
floor. A caustic solution is pumped through the conduits and sprayed 
through the nozzles into the space beneath the floor. Although the caustic 
solution cleans the, surfaces it contacts, it is difficult to ensure that 
all of the necessary surfaces are adequately contacted by the solution. 
Furthermore, a caustic film is left which can be difficult to remove and 
which adversely affects the steeping process, besides corroding some of 
the surfaces and/or fittings which it contacts. 
The present invention provides an improved steep tank floor design which 
avoids the shortcomings of the prior art. 
SUMMARY OF THE INVENTION 
In accordance with the preferred embodiment, the invention provides a 
flat-surfaced steep tank floor. A primary channel extends diametrically 
across the surface of the floor. A plurality of secondary channels in the 
surface extend transversely to and intersect the primary channel. Each 
channel has a perforated, removable cover. 
The channels are perforated at regular intervals. Aeration conduits extend 
beneath the floor in communication with the respective channel 
perforations. 
To facilitate cleaning, the primary channel slopes downwardly from one side 
of the floor to the opposite side thereof; and, the secondary channels 
slope downwardly from the sides of the floor to the primary channel. The 
channels are advantageously "U" shaped in cross-section, to further 
simplify cleaning. The covers are pivotally connected to the respective 
channels, with a lifting mechanism being provided to controllably raise 
and lower the covers.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 depicts a steep tank having a floor constructed in accordance with 
the invention. Other aspects of the FIG. 1 steep tank are conventional and 
are therefore described only briefly. 
Steep tank 10 is cylindrical in shape. Floor 12 (hereinafter described in 
greater detail) is constructed atop concrete base 14. Air conduit 16 is 
coupled to floor 12 as hereinafter described to aerate the contents of 
tank 10 with air supplied by blower 18, which also extracts carbon dioxide 
from tank 10 via plenum 20. 
Barley kernels (not shown) are fed into tank 10 by conveyor 22, valving 
system 24 and chute 26. A conventional loader/unloader 28 is rotatably 
supported within tank 10 on column 30. Barley fed into tank 10 is 
distributed over floor 12 by paddles 32 on the underside of 
loader/unloader 28 as loader/unloader 28 rotates about column 30. Lifting 
cylinder 34 gradually raises loader/unloader 28 as tank 10 fills with 
barley. 
When sufficient barley has been fed into tank 10 water is added to the 
barley. After a suitable duration the steeped barley is extracted from 
tank 10 through discharge outlet 36 by counter-rotating loader/unloader 28 
so that paddles 32 sweep the barley toward the center of tank 10 for 
extraction through discharge outlet 36. Column supports 38 project 
outwardly from the lower end of column 30 at discharge outlet 36. After 
the steeped barley has been extracted as aforesaid, tank 10 is cleaned and 
then refilled with barley and water to make a fresh batch of malt. 
As depicted in FIGS. 2 and 3, floor 12 has an upper, flat steel surface 40. 
A primary channel 42 extends diametrically across floor 12. To simplify 
drainage during cleaning of tank 10, primary channel 42 slopes downwardly 
from one side of floor 12 to the opposite side thereof, as best seen in 
FIG. 3. Channel 42 may be about four feet wide in a typical steep tank 
having a diameter of about fifty feet, about two feet deep at its shallow 
end and about four feet deep at its opposite end. Channel 42 is preformed 
of steel. Concrete base 14 is pressure grouted beneath channel 42. 
A plurality of secondary channels 44 extend on either side of primary 
channel 42. Each secondary channel 44 intersects primary channel 42 and 
extends transversely away from primary channel 42 to the side of floor 12. 
As best seen in FIG. 4, secondary channels 44 slope downwardly from the 
respective sides of floor 12 to intersect primary channel 42, which 
further simplifies drainage during cleaning of tank 10. Secondary channels 
44 may be spaced apart on about two foot centers, with each channel being 
about six inches wide and six inches deep. Secondary channels 44 are 
preformed of steel, with concrete base 14 being pressure grouted beneath 
the channels. 
As shown in FIG. 5, secondary channels 44 are preferably "U" shaped in 
cross-section to avoid sharp corners and simplifying cleaning. Secondary 
channels 44 incorporate perforations 46 at spaced intervals to facilitate 
aeration. More particularly, an aeration conduit 48 extends beneath each 
row of perforations 46. Compressed air can be forced through conduits 48 
and perforations 46 to aerate the barley-water steeping mixture. 
FIG. 5 also depicts perforated steel, hinged cover 50, one of which is 
provided atop each secondary channel 44. A rod 52 (best seen in FIG. 6) 
extends beneath one longitudinal edge of hinged cover 50. Split bushings 
54 couple rod 52 to the underside of cover 50 at spaced intervals. The 
cylinder end of an extendible cylinder 56 (only one of which is shown in 
FIG. 7) is pivotally connected to fixed support 58, with the cylinder's 
rod end being connected to crank arm 60 which is in turn fixed to rod 52. 
When cylinder 56 is actuated by suitable control means (not shown) its rod 
extends, rotating crank arm 60 and thereby rotating rod 52 such that cover 
50 pivots with respect to rod 52 into a vertically upright position, thus 
affording unimpeded access for cleaning the interior of secondary channels 
44. Primary channel 42 is also covered, and a similar lifting mechanism is 
provided to raise and lower the cover. 
It will thus be understood that the invention provides a steep tank floor 
which can easily be cleaned without exposing workmen to potential safety 
hazards by requiring them to work beneath an elevated floor. The invention 
also avoids the difficulties inherent in manually cleaning the underside 
of an overhead floor. Indeed, much of the necessary cleaning operation may 
be performed by a conventional, downwardly directed clean-in-place 
cleaning system incorporated into loader/unloader 28 in conventional 
fashion, thus minimizing the manual labour required to complete the floor 
cleaning operation. 
As will be apparent to those skilled in the art in the light of the 
foregoing disclosure, many alterations and modifications are possible in 
the practice of this invention without departing from the spirit or scope 
thereof. Accordingly, the scope of the invention is to be construed in 
accordance with the substance defined by the following claims.