1
Table of Contents
Water Storage (GB) …………………………………………………………………………………………………2
Stillage Disposal (Environmental) (TC)…..………………………………………………………………..4
Charcoal Filtering System (JC).…………………………………………………………………………………6
Barrel Transportation (KB & JC...……………………………………………………………………………10
Pumping System for Stillage (JO)..……...…………………………………………………………………13
2
Literature Review
Introduction
The art of craft brewing and distilling liquor has recently been on the rise in popularity due to
successful television programs and the growing appreciation for local products. One of these distilleries,
Grand Rivers Spirits, has become increasingly popular in Southern Illinois. Due to the growing demand
for product, several engineering concepts are needed to help the company improve efficiency, quality,
and cost for their signature product, Red Eye Moonshine. Barrel transportation, water storage, charcoal
filtration, and stillage removal have been flagged by Grand Rivers Spirits to be considered by the Saluki
Engineering Company. A literature review of notable works performed by experts in these fields has
been composed by the Shiners Team to outline tour ideas leading into the design phase of this project.
Water Storage
Our client explained his need for a way to store a large quantity of water. Adding water storage
will provide protection from complications with the supply in the case of a natural disaster, water line
break, or boil-water order and will help remove any inconsistencies in the taste due to changing levels of
chemicals added by the supplier at the treatment facility. Since space is a primary concern, these water
tanks must be safely placed in a location out of the way from normal daily operations.
Currently, the mash is partially composed of water straight from the tap. The resulting alcohol is
also diluted with tap water, making the taste of the water an important contributor to the taste of the
final product. The water tap on site is supplied by the Murdale Water District. Throughout the year, the
chemical composition of the water can vary. Since the water comes from many different sources, (lakes,
wells, ponds, etc.) and travels through miles of piping, it can easily become contaminated with bacteria
from this variety of sources [1]. In order to remove this bacterium and ensure clean, safe tap water, the
EPA allows water suppliers to treat with chlorine and monochloramine [2]. While proven to be effective,
these chemicals cause a noticeable change in the taste of the water. These chemicals are added in
amounts directly related to the amount of bacteria found in the water, meaning they fluctuate
throughout the year. Bacteria thrive in heat, so the warmer summer months call for a higher chemical
content. The idea behind adding water storage is to remove any inconsistencies in the water that
supplies the distillery to provide a more consistent-tasting product.
It was suggested that the water be stored in the loft area of the distilling site. The loft is
constructed with 2”x12” Southern Yellow Pine lumber (Grade No. 2) with 12” center spacing and a “
span. With projected 500-1000 gallon storage, weight is a major concern. Live load is the amount of
weight added to a structure and does not include the weight of the structure itself [5]. Table 1 shows
various allowable floor spans for given lumber dimensions with a live load of 60lbs/ft2. The existing
conditions of the structure are highlighted. The spans between joists must be close enough to support
the desired weight. According to Table 1, without modifying the structure, the span must be about 17.5
feet.
3
Table 1: Maximum Lumber Spans
Maximum Span (ft - in)
Nominal
Size
Joist
Spacing
(inches)
(inches)
Selected
Structural
No. 1
No. 2
12
13' - 1''
12' - 7''
12' - 4''
16
11' - 11''
11' - 5''
10' - 8''
24
10' - 5''
9' - 4''
8' - 8''
12
16' - 8''
16' - 1''
15'
16
15' - 2''
13' - 11''
13'
24
13' - 3''
11' - 4''
10' - 7''
12
20' - 3''
18' - 7''
17' - 5''
16
18' - 5''
16' - 1''
15' - 1''
24
15' - 10''
13' - 2''
12' - 4''
12
23' - 11''
20' - 10''
19' - 5''
16
21' - 8''
18'
16' - 10''
24
17' - 9''
14' - 8''
13' - 9''
2x8
2 x 10
2 x 12
2 x 14
Lumber Grade
It is important to select a tank with a surface area big enough to distribute the weight so it may
be supported by the wood structure. There is a vast market for plastic water storage tanks of many
different sizes, and it would be more economical to purchase an existing tank instead of designing and
constructing our own. The tanks on the market also come with warranties, making them an even more
attractive option.
It is also imperative to the client to automate the way these tanks are filled. A simple float
switch would provide a cheap, effective way to automate the system. A float switch is used in
conjunction with a water pump to start or stop the water flow into a container based on the water level
of the system. A lever switch mechanism is put in motion by the lack of a buoyancy force created by the
falling water level, eventually turning the switch on and starting the operation of the water pump to fill
the voided area back up with water. When the water level begins to rise, the buoyancy force will cause
the lever to rise with the water level. Eventually the water level will be high enough to open the switch
and turn off the water supply [3]. A simple mechanism like this would remove the need for manual
operation and make it easier for the client to maintain this addition. Instead of using the float switch
with a water pump, it could be used in conjunction with a valve at the tap. The water pressure from the
tap would eliminate the need for a pump. Figure 1 is shown below to clarify the type of switch that
would be practical for this application.
4
Figure 1
Another problem one would encounter while using water from the tap is that of sediment.
Sediment collecting in the bottom of the tank will cause corrosion in any of the metal pipe fittings or
components that come in contact farther downstream [4]. This can be corrected with proper periodical
cleaning techniques. In order to avoid the sediment issue completely, water de-ionization could be
used. This method can be hazardous as well. De-ionized water can be corrosive, and the pH must be
maintained with enzymes. Enzyme treatment can become very expensive and require more costly tincoated tanks. Additionally, the de-ionizing units are very large, making them expensive to ship, maintain
and store in a facility where space is limited.
Stillage Disposal
Stillage and spent wash are terms used to describe the byproducts of alcohol production. These
effluents are created in mass quantities with liquor production. Up to 15 liters of stillage is produced for
every liter of alcohol. The wastewater produced by the distillation process normally ranges from 70-80
degrees Celsius [7]. Wastewater can be found from all steps of the manufacturing process as shown in
table one.
Table 2 Samples of Distillery Waste Water [6]
Disposal of stillage has posed serious environmental problems in many parts of the world.
Countries such as India have had serious issues with disposing spent wash. On average, India produces
2.7 billion liters of alcohol and 40 billion liters of spent wash and stillage annually [5]. The stillage of the
285 distilleries of India has posed a serious threat to the environment and is considered among the top
5
seventeen pollution-producing, commercial enterprises [6]. Pollution from alcohol byproducts
production is not limited to India. The disposal methods of stillage can affect the environment
worldwide.
The negative effects of spent wash and stillage on the environment can be attributed to its
physical properties. Stillage is dark in color, pungent, and acidic with high chemical and biochemical
oxygen demands [6]. In addition to these environmentally hazardous properties, spent wash can also
contain high volumes of substances such as nitrates, sulfates, chlorides, and other inorganics [7]. A
specific list of these properties is located in table three.
Table 3 Units in mg/L Except pH [7]
Studies have shown that the existence of stillage byproducts when introduced to streams and
lakes can cause harm to local organisms and aquatic life, including asphyxiation, intoxication, and death.
These inorganic, byproducts can also be harmful to plant life. The dark color of the stillage can limit
aquatic vegetation to produce chlorophyll through photosynthesis [6]. The stillage can also inhibit plant
growth on land by altering pH levels and soil nutrients [7].
In order to properly dispose of and even recycle stillage, several techniques have been
developed. One popular way to reuse spent wash, and the standard operating procedure of Grand
Rivers Distillery, is to recycle the waste as food for livestock. Still waste and sludge in its initial state can
be used as food for most popular forms of livestock for up to three days after being produced. After the
three-day period, the waste starts degrading. In order to fix this many still owners and farmers have
developed an evaporation technique to ensure the safety of the livestock while eating dry mash waste.
The stillage must go through an evaporator, centrifuge and dryer as shown in figure 2 [8].
6
Figure 2 In wt. % [8]
In addition to recycling mash effluent into livestock feed, many farmers can also use stillage as a
fertilizer for their crops. Despite the damage that can be caused to vegetation by the presence of
stillage, the nutrients and substances that stillage contains can, in fact, help to improve the growth and
production of many crops. The seed yield of a crop with the addition of raw stillage can produce 557
kg/ha compared to the 310 kg/ha that was produced by the control [7]. The fertilizer produced from still
production could be cost -effective to farmers due to its low price or even free availability. Despite the
low price, it is necessary for the farmers to conform to several laws dealing with the use of spent wash
as fertilization. These laws can include altering the concentration of the spent wash as well as being
prohibited from using stillage fertilization during certain seasons [8].
Charcoal Filtering System
The craft breweries, which usually produce small batches from selective local ingredients, are
growing due to their authenticity [9]. In order to reach this authentic taste, distilleries must balance the
elements of the spirit, such as esters and ethyl acetate. “The presence of high molecular weight esters
and ethyl acetate, which are associated with unpleasant odors, is sometimes related to excess acidity.
However, when at low levels they contribute to a pleasant flavor” [10]. Distilleries usually apply filters to
trap the undesirable compounds and impurities.
The client has requested a charcoal filtering system because as one source states, “Activated
carbon is the most popular and the cheapest material used in purification of alcohol…” [11] The client is
a small distillery and cost is one of the highest priorities throughout this project and their operations.
Activated Carbon filters may be used numerous times, and have been tested and proven capable of
filtering distilled alcohol very well due to its “extended surface area, microporous structure, high
absorption capacity, and high degree of surface reactivity” [12]. The empty spaces in the carbon grains
define the activity level of the carbon. As parts of the carbon become gaseous, open areas or pores, are
left in the solid carbon [12]. These pores allow the carbon to filter out different sized impurities. High
level activated carbon has the largest number of empty spaces, and this class is not suitable for filtering
alcohol [11]. The pores are too large to sift out the unwanted particles in the spirit. The pores and their
corresponding functions are listed in Figure 3 and Table 4.
7
Figure 3: Activated Carbon Pores [11]
Table 4: Activated Carbon Pores’ Radiuses and Functions [11]
Pore Size
Radius of Pore (nm)
Function of Pore
Percentage Surface
Area
Macro
>25
Transport of Liquid
1
Meso
1-25
Absorption of Particles
1-10
Micro
<25
Absorption of Particles
90-98
Activated Carbon is not only effective because of its porosity but also absorptivity. This carbon
uses van der Waals interactions to attract non-polar organic molecules that have been dissolved in
water. This phenomenon makes these filters highly effective for removing chlorine, iodine, mercury,
some inorganic compounds, many organic contaminants (formaldehyde), and volatile organic
compounds. However, activated carbon struggles to bind with alcohols making it ideal for use in
distilleries [13]!
A property of activated carbon to consider is the surface area. The surface area of activated
carbon is extraordinarily large, “one gram of industrially produced activated carbon may have a surface
area of 400- 1500m2 (a football field is about 5000m2)” [13]. This is a very significant amount of space
for unwanted substances to bind to. Figure 4 is close-up of a piece of activated carbon about 1mm
across and its pores. All of these pores are what creates the large surface area of the carbon.
8
Figure 4:
(a) Activated Carbon Grain [13]
(b) Close-up of Pore Space [13]
The pore structure is determined by the materials used to make the charcoal. This is extremely
beneficial to manufacturers because they are able to control the distribution of meso and micro pores.
Consumers should be aware of the raw material used to create the activated carbon filter to ensure that
the filter suits their needs. Table 5 further explains the concept of raw materials and the pore sizes
associated with them.
Table 5: Examples of Raw Materials
Raw Material
Pores Present
Character
0.4-1.4 (popular)
Micro
Stone Coal
Grain Size (mm)
Multipurpose
Meso
0.4-0.85 (new)
Lignite
Meso
Pulverized
1-4 some larger
Coconut Shell
Micro
Fine
<1
Another key aspect in the design of activated charcoal is the filter type. Activated carbon
filtering falls into the rough filtering category. Roughing filters are usually composed of a series of
graded beds (or layers) that start out coarse and get increasingly finer [14]. These filters are categorized
by flow patterns.
9
Figure 5: Structure of Horizontal and Vertical Flow [14]
Table 6: Roughing Filter Categories
Flow Pattern
Subset
Downflow
Vertical
Upflow
Pros
Cons
Simple Self Cleaning
Requires extra pipes
and inlet and outlet
components
Occupies Minimal
Floor Space
Large Storage Capacity
Horizontal
None
Less Sensitive to Flow
Rate Changes
Requires a large
amount of floor space
The horizontal filtration system has large storage capacity, but the amount of space the system
would take up when not in use makes it impractical. Therefore, the subsets of the vertical flow pattern
will be analyzed.
10
The vertical flow filters can be broken into the two categories, the downflow and the upflow.
The downflow roughing filter is used whenever the fluid being filtered sits above the filter. This vertical
filter uses the weight of gravity to force the fluid through the filter, and is less expensive and easier to
use because the force of gravity on the fluid will push the fluid through the filter without any added
pumps. However, this method is much slower than the upflow method. The upflow roughing filter
method is utilized when the fluid being filtered is forced up through the filter by means of an applied
force (such as a pump). Initial cost of this method will be high, but may save time especially if the
business and volumes of alcohol being filtered continues to grow.
All of the characteristics of activated carbon filters mentioned thus far are deciding factors in
the filter choice. The filters must be “a pure (food grade) activated carbon for foodstuffs, like drinking
water or alcohol” [11].
Barrel Transportation
Whiskey does not get the color and some of the extraordinary flavors until after aging. Whiskey
is aged in barrels, or casks, ranging from 5 gallons to 59 gallons. In the United States corn whiskey is not
required to be aged in wooden barrels, but all other whiskeys are required to be aged in charred oak
barrels for a minimum of two years. A distiller also has the ability to control the environment of the
aging room to determine the speed of aging, specific flavors that are extracted and many other
important factors in the aging process [15]. Moving these heavy barrels for a distiller can become quite
the operation, and a major factor that can be accompanied with this is the amount of space available to
transport the goods; dealing with small spaces and heavy objects can be a difficult task. Finding a
manually or electrically operated lift with a small turning radius is ideal for small scale operations. [KB]
In every work environment, safety is a high priority. Heavy lifting hazards come in many forms,
such as posture and strain on a human body, rolling objects, and inadequate hand holds. The solution to
these risky issues in the work area would be to use an assisted lifting system [16]. Many different types
of lifts are available and each has its specific benefits and uses. [JC]
Stacker Lifts are lifts that can be powered by battery operated motors or manually operated
jacks much smaller than a forklift. Stacker lifts provide a high lift and easy maneuverability within small
spaces such as aisles. The primary components of a lift consist of a motor or manual lever that can
operate a hydraulic piston cylinder or a series of chains on pulleys to raise the object. The object is
raised up on a set of forks of various widths to accommodate the specific load. The frame is specifically
designed to carry large weights but still be able to be moved around on casters. Each lift has
specifications of load capacity, raised height, lowered height and dimensions of the frame, and mobility
of forks. Price, base width, load capacity, and raised height are taken into a greater consideration for the
client. In the table a variety of lifts are shown. [KB]
Scissor lifts are also hydraulically operated and they operate under an electric motor because
they are made to lift and carry people. A hydraulic piston is extended and raises the arms. Each arm is
fixed at one point and moves on a slider joint at the other, this makes the lift more balanced than a
stacker lift, and safer as a result. This lift is much larger and is very cumbersome, which is a downfall,
because space is a primary asset to the work environment. Scissor lifts can be made to carry extremely
11
heavy loads and to extend exceedingly higher than a stacker lift. This type of lift provides a much
sturdier base due to the design of the supports. [JC]
Lifts can be very specific to the field for which they are used. For example, the “HD Wine Vat
Lifter,” is used specifically to lift and transport wine and spirits in wooden barrels. This type of lift
combines different qualities from many lifts to produce an ideal lift system for the work environment.
The lifts include a motor driven ball screw which is responsible for lifting the fork attachments. The
motor is a 24-volt DC motor which powers the lift as well the wheels for an efficient mode of
transportation [17]. [KB]
Table 7: Comparison of important characteristics of lifts
Type of Lift
Load Capc.
(lbs)
Raise Height
(in)
Manual/ Elec
Width of Base
(in)
Price ($)
Hydraulic
2,200
59
Manual Lever
27.5
2,200
Wheel Winch
750
54
Manual Crank
22
788
Hydraulic
5,511
62
Electric
28
4,600
Hydraulic
1,500
137
Electric
30.5
4,000
Hydraulic
2,000
62
Manual Lever
30
4,000
[18] [KB]
Hydraulic lifts have been an important role in many thriving industries and are based on basic
concepts of incompressible liquids. Gases have the ability to be compressed to a great extent, while
most liquids are labeled as incompressible. Gases used in hydraulics are called pneumatic hydraulics, but
liquids are simply called hydraulics. Hydraulic systems generally use petroleum oils but originally started
with water because of its availability. Fluid power systems use pressurized fluid that puts force on a
cylinder [19]. The basic forces and dimensions are shown in figure 6 and figure 7. [JC]
Figure 6: Piston cylinder with basic forces [JC]
Figure 7: Piston cylinder force on fluid [JC]
12
Another type of lift that would be possible for Grand River Spirits to use is a jack lift. A jack lift is
a hydraulic lift that uses pressure on fluid to help lift an object. Every jack consists of six main
components, a reservoir, a pump, a check valve, a main cylinder, a ram piston, and a release valve. Each
component is a crucial part to the performance of the jack. The reservoir is used to hold the hydraulic
fluid. The fluid is then transferred to the pump on the intake stroke then raises the pressure on the
power stroke. This pushes the fluid through the check valve which remains open to allow fluid to pass
through. Once fluid stops the check valve closes to insure no damage is done to the pump. From here
the fluid then moves to the main cylinder due to the force on the ram piston allowing the pressurized
fluid to fill the main cylinder. Finally when the jack has lifted the object the pressure is released allowing
the ram piston to return back into the main cylinder. The released valve is opened and the fluid is then
sent back into the reservoir so the jack can lift the next object [20]. [KB]
Piston & Cylinder
Frame
Forks
Handle
Base Width
Casters
Figure 8: Stacker lift with labels [17]. [KB]
13
Pumping Systems for Stillage
Stillage is the waste created from the distilling process. This waste typically contains 5-8% solid
content, and exits the still at roughly 70-80°C (158°-176° F) [23]. The stillage that must be disposed will
need to be moved automatically from the still to be stored outside the distillery. Currently, the waste is
deposited into a bucket and moved manually to vats inside the distillery. This must be addressed
because the current method requires much time and tedious manual effort.
Centrifugal Pump
Centrifugal pumps collect liquid in a casing and take the kinetic energy of the liquid and convert
it to pressure energy by way of an impeller. The screw-shaped impeller forces fluid collected axially at
the inlet vertically through the outlet, as shown in Figure 9. This type of pump is relatively efficient, and
results in inexpensive pumping [21]. These pumps are normally used for high volumes of sludge, or
liquids with a solid concentration of about 2-3%. However, the pump must be sized very accurately to
avoid clogging due to solid content and taking in too much liquid at once, which can result in high
amounts of maintenance for the pump itself [22].
Figure 9 - Centrifugal Sludge Pump [25]
Combined Screw Centrifugal Pump
The combined screw centrifugal pump was designed specifically to address clogging issues that
plague typical centrifugal pumps. Combined screw pumps function very similarly to typical centrifugal
pumps, however, a second impeller located near the main impeller reduces the change in direction of
the fluid and forces excess fluid through the outlet, as shown in Figure 10. This keeps solids from
gathering and clogging the pump [22]. These pumps have higher efficiencies and greater reliability, but
they typically cost more to buy and operate than ordinary centrifugal pumps. They also tend to pump
fluids to a higher pressure head more easily. These pumps are generally used for punctuated pumping
rather than continuous pumping [21].
14
Figure 10- Combined Screw
Centrifugal Sludge Pump [24]
Piston Pumps
The piston pump is one of the more simplistic, yet effective, sludge pumps. Fluid is fed into the pump
and pressurized by a piston, as shown in Figure 11. After pressurization, the fluid is discharged into a
piping system. The flow rate into and out of the pump is regulated by valves. The power input and
stroke length of the piston itself can be adjusted easily to fit the needs of the pumping job [22]. This
type of pump is easily maintained; however, the noise and vibrations caused by the moving piston could
prove to be problematic when the pump is connected to rigid pipes in a confined space [21, 22]. For a
small, temporary task such as the disposal of stillage in this particular distillery, a piston pump may not
be ideal.
Figure 11- Piston Sludge Pump [26]
15
Piping System
Once the stillage is pumped, it must be transported to tanks outside the facility. A relatively simple
piping system will be installed to perform this task. The pipes must withstand the high temperature of
the stillage without corroding. Hence, the thermal expansion properties of common pipes must be taken
into account.
The most viable option for piping the stillage from the still to the storage vats outside the facility is to
use ASME 31.11 Slurry Transportation Piping Systems. These systems are designed to transport sludge
solutions with a much greater solid content than that of the stillage and can handle any pressure
fathomable in this project. Additionally, these pipes are approved to handle temperatures up to 250°F,
well above the maximum temperature of the fluid. This system will be helpful in avoiding clogging or
wear that may become commonplace in typical steel or PVC pipes [27].
Another option is the ASME B 31.4 Pipeline Transportation System. Like the Slurry Transportation
System, these pipes can handle a wide temperature and pressure range. However, this system is
designed to carry much less viscous fluids much further distances than is necessary for this project. This
particular style of piping is designed more for oil pipelines than stillage [27].
16
Refrences
[1]
Centers for Disease Control and Prevention. (2012). Disinfection with Chlorine &
Chloramine. [Online]. Avaliable FTP:
http://www.cdc.gov/healthywater/drinking/public/water_disinfection.html
[2]
U.S. Environmental Protection Agency. (2012) Basic Information about Disinfectants in
Drinking Water: Chloramine, Chlorine and Chlorine Dioxide ; Avaliable FTP:
http://water.epa.gov/drink/contaminants/basicinformation/disinfectants.cfm
[3]
Stephen P. Johnson, “Float Switch,” US Patent # 4262216 Apr, 14, 1981.
[4]
Carl T. Fliss, “Water Storage Tanks and the Method of Making the Same,” US Patent #
3207358. Sept, 21, 1965.
[5]
G. Kumar, S. Gupta, G. Singh, Biodegradation of distillery spent wash in anaerobic hybrid
reactor, Water Research 41 (2007) 721-730.
[6]
Y.Satyawali, M. Balakrishnan, Wastewater treatment in molasses-based alcohol
distilleries for COD and color removal: A review, Journal of Environmental Management 86 (2008) 481497.
[7]
S. Mohana, B. Acharya, D. Madamwar, Distillery spent wash: Treatment technologies
and potential applications, Journal of Hazardous Materials 163 (2009) 12-25
[8]
V. Sajbrt, M. Rosol, P. Ditl, A comparison of distillery stillage disposal methods, Acta
Polytechnica 50 (2010).
[9]
William Gurstelle, “WHISKEY REBELLION,” Popular Mechanics, vol. 189, pp. 58-63, Feb,
2012. Available: http://ehis.ebscohost.com/
[10]
L.R. Galego et al., “Preparation of novel distinct highly aromatic liquors using fruit
distillates,”International Journal of Food Science and Technology, vol. 46, pp. 67-73, 2011. Available:
http://ehis.ebscohost.com/
[11]
Activated carbon for the purification of alcohol, Gert Strand, Malmoe, Sweden, 2001.
Available: www.slideshare.net
[12]
Sarayu Mohana et al., “Distillery spent wash: Treatment technologies and potential
applications,” Journal of Hazardous Materials, vol. 163, pp. 12-25, 2009. Available:
www.elsevier.com/locate/jhazmat
[13]
Josh Kearns. (2007). Charcoal Filtration Basics.[Online]. Available:
http://www.aqsolutions.org/resources/Charcoal_Filtration.pdf
[14
O.I. Nkwonta et al., “Turbidity removal: Gravel and charcoal as roughing filtration
media,” South African Journal of Science, vol. 106, pp. 1-5. Nov, 2009. Available:
http://ehis.ebscohost.com/
[15]
B. Owens. (2009). Craft of Whiskey Distilling. 1st ed. American Distilling Company, 2009,
ch. 4, pp44-50
17
[16]
OSHA. (2013, April 25). Materials Handling: Heavy Lifting[online]. Available:
https://www.osha.gov/SLTC/etools/electricalcontractors/materials/heavy.html
[17]
PackLine. (2013). Wine and Spirits Barrel Lifter [online]. Available:
http://www.packline.co.uk/wine_barrel_handling.html
[18]
G.I. (2013, March 07) GlobalIndustry.com. [online]. Available:
http://www.globalindustrial.com/c/material-handling/lift-trucks
[19]
A. Esposito. (2009). “Hydraulic Basics,” in Fluid Power with Applications. 7th ed. City,
Prentice Hall, 2009, ch. 2, 3, 5. pp23-150
[20]
R.J. Tafialaw. (1996, March 30). Jacks Basics Page [online]. Available:
http://www.hyjacks.com/H7.HTM
[21]
Richard O. Garbus, "Types of Pumps," in Pumping Station Design, Stoneham,
Massachusetts: Butterworth, 1989, ch.11, pp. 247-84.
[22]
Carl N. Anderson, David J. Hannah, “System Design for Sludge Pumping,” in Pumping
Station Design, Stoneham, Massachusetts: Butterworth, 1989, pp. 480-505.
[23]
Vaclav Sajbrt et al., "A Comparison of Distillery Stillage Removal Systems," Acta
Polytechnicha, 2nd ed. Vol. 50, 2010.
[24]
Horizontal Centrifugal Ash Slurry Pump [Online] Available :
http://www.alibaba.com/product-gs/490917006/horizontal_centrifugal_ash_slurry_pump.html
[25]
Products & Services: Sludge Handling [Online] Available:
http://www.waterworld.com/articles/print/volume-29/issue-6/products/products-services-sludgehandling.html
[26]
Komline-Sanderson Plunger Pump [Online] Available:
http://www.komline.com/docs/ks_plunger_pump.html
[27]
ASME B31 - Standards of Pressure Piping [Online] Available:
http://www.engineeringtoolbox.com/asme-b31pressure-piping-d_39.html