Sartell Paper Mill
Encyclopedia
The Sartell Paper Mill, officially the Verso Paper Sartell Mill, is a paper mill
located in the city of Sartell
in the U.S. state
of Minnesota
. The mill is owned and operated by Verso Paper.
from Wisconsin
and Michigan
and was formed on May 10, 1905 with a capitalization of $200,000. The stock shares were $100 each.
It was the intent to build the mill at Sauk Rapids
at the location of the Sauk Rapids Bridge
, but the owners of the power rights were asking what was felt to be an exorbitant price. Watab Pulp and Paper went further upstream, to Sartell, and for a sum of $1.00 made an agreement with the owners of the existing saw mill to move it from the west side of the Mississippi River
to a point just inside the village limits.
The plant started operations with No. 1 paper machine in September, 1905. No. 2 paper machine was built in 1910. The company then produced newsprint
until 1930, when the conversion to groundwood book and magazine
papers began.
Many changes have taken place since the days when log drives
down the Mississippi River
were common and the paper mill was experimenting using corn
stalks as a raw material.
During the 1930s, recycled
magazines were a prime source of wood pulp
. The waste magazines were brought by rail from Chicago
in bales weighing up to 2,000 pounds. In the “sorting room,” paper clip
s and staples
were removed. The waste was then sent to the cookers for deinking and bleaching. The conversion plant operated through the 1930s until the end of World War II
.
The war years brought other changes to the Sartell mill:
At the end of the war, the mill closed the finishing operation where paper was sheeted and cut to size. Since that time, all paper manufactured at Sartell has been shipped in roll form.
St. Regis bought Watab Pulp and Paper and its properties in 1946. The transition was smooth with minor changes in mill management.
Plant operations changed immensely. Until 1948, 100-inch wood was handled by hand. Large unloading crews handled the wood from railroad cars to a system of conveyors for building huge storage piles on the river’s edge.
Over the years, many changes had taken place with the mill’s machinery:
Another operation that is no longer performed relates to storing groundwood. In 1934, a large concrete pad was constructed for storing “lapped groundwood pulp. Because of the water-driven groundwood mill, at time of high water availability, excess groundwood was manufactured for use when the water flow was low. Separation of frozen laps was difficult during cold Minnesota winters. When separation was not possible with crowbars
, dynamite
was used. The lapped groundwood pulp was then brought in to the mill and placed into beaters for repulping and use.
In 1957, No. 1 paper machine had a major rebuild. The same was done the following year on No. 2 paper machine. Both machines were sped up with the addition of new steam turbine drives and new headboxes.
The mill had one of the earliest supercalenders in the industry. In 1960, No. 1 and No. 2 supercalenders were installed.
Since the 1960s, uncoated supercalendered grades of paper have been manufactured. In the past twenty years, basis weight of these papers has been reduced from a 43 pound sheet that was used in Family Circle
magazine to, in some instances, as low as 26 pound.
St. Regis was one of the first companies in the area to install equipment for fly ash removal and wastewater treatment facilities. The wastewater treatment facility was one of the first in the papermaking industry
; much experimentation has been done to improve the operation. Sartell won an Izaak Walton League award for clean water related to these efforts. The mill has also been commended seven times by the Minnesota Pollution Control Agency since 1985 for excellent wastewater treatment facility operation and effluent quality.
The mill has also been a pioneer in burning bark and wastewater
sludge, very significant with the solid waste considerations of today. The bark burning system went into operation in 1961 and the secondary wastewater treatment system started up in April 1973.
Although the No. 3 paper machine project of 1982 is referred to as an expansion, it consisted almost of an entire mill replacement or rebuild. Virtually all areas were affected, except existing paper machine and supercalender areas. Existing water supply systems, filtration systems, shops, stores, primary electrical, and some effluent treatment facilities were all replaced. April 2000 brought an upgraded gapformer installation, including a headbox which was replaced and updated with new dilution control technology.
No. 1 and No. 2 paper machines operate at 1,950 feet per minute and 1,880 feet per minute respectively and produce about 280 tons of publication grade paper per day. With the addition of No. 3 paper machine, currently operating at 4,150+ feet per minute, another 600 tons are produced daily.
.
The woodroom consists of two independent processing lines with a common bark
system. Each line is designed to produce 100 cords per shift of high quality, bark-free chips.
Fir
is fed through the softwood
line and debarked in a 12-foot by 68-foot debarking drum. Equipment has been added for log washing and deicing prior to the drum to facilitate debarking. After debarking, the wood flows through a log inspection and sorting system where individual sticks may be recycled to the drum. Properly debarked logs are directed to a 12-knife Carthage chipper. Chips are screened and conveyed to chip storage bins.
The aspen
, or hardwood
, line is similar to the softwood line except that logs are debarked in a Nicholson mechanical ring debarker. Wood is chipped separately and stored in a 400-cord chip bin.
The TMP pulp discharged from the tertiary refiner is treated for latency removal, series screened, cleaned, thickened, and stored in two medium density storage tanks. Screened rejects are further refined, screened, and cleaned before storage. The unbleached TMP is recovered from storage and bleached to brightness levels in the bleach plant.
mills. Fork trucks
deliver a six-bale stack to bale handling equipment for destacking and dewiring. A dewiring system, the first automatic one in the industry, dewires bales before they are dumped from the conveyor to the pulper; the slush pulp is then pumped to a soak chest, refiners, and storage tank.
. Coating ingredients are mixed in a slurry makedown tank, screened, and pumped continuously through various stages for enzyme addition and cooking.
Coating is discharged into a flash tank where flash steam is directed to a condensing chamber where heat is recovered as hot water. Finished coating is stored for eventual use on the paper machines.
. Both machines are the same size and general configuration. The fabric width is 314 inches, design speed was 3,500 feet per minute, and the maximum salable trim is 280 inches. The design basis weight was 34# and at design speed, the machine would produce 480 tons per day. Modifications have since been made and No. 3 paper machine now operates at 4,150+ feet per minute, producing 600 tons of salable paper per day.
A Voith dilution control headbox was selected to improve the ability to control profile and formation.
A gap former was chosen to improve sheet formation and paper quality essential to raw stock manufacture.
The press section is a Beloit twinver with an inclined straight-through, grooved third press. This type of press section was selected because of its cleanliness during operation, efficient water removal capability, and successful operation in the past.
The main dryer section consists of 43 six-foot dryers split into four sections.
The two-roll machine calender is equipped with two variable crown rolls and heating capability for caliper control.
The Beloit short-dwell nip coaters and later EXCEL Coaters in 1998 were included to apply five pounds of coating to each side of the sheet. Conservation measures have also been taken in reclaiming coating and recycling it to the coated broke system for recovery.
The paper is wound onto individual rolls on a Jagenberg vari-top single drum winder. The maximum design speed of this unit is 8,500 feet per minute. This winder is also highly automated to maximize productivity.
for identification and inventory control.
, can be “spotted” inside the building. This amount of storage is necessitated with this seasonable type of business.
is generated in a Babcock and Wilcox stoker-fired coal
boiler with a capacity of 270,000 pounds of steam per hour. The boiler is designed to burn a combination of coal, bark, wastewater sludge, and tire chips. Steam is distributed to process at 450, 150, and 50 psi.
A Brown Boveri double-extraction back-pressure turbine (manufactured in St. Cloud
) has also been installed. The unit can generate 20.8 MW at maximum, but the actual generation is dictated by steam usage.
The primary fuel is low-sulfur
Kentucky
coal, delivered by truck. The coal is unloaded into a concrete lined storage area. Belt conveyors transport the coal to the crusher/transfer house, then to the boiler bunker.
The mill uses and returns (cleaner than the river itself) ten million gallons of water per day. Mill effluent is treated in the primary clarifier for solids removal. An activated sludge aeration basin with secondary clarifier is used for BOD reduction before discharge to the Mississippi River
. Sludge from the clarifiers is dewatered on a belt filter
press and a screw press. The thickened sludge is mixed with bark and fed to the boiler for incineration.
Some of them are:
High speed fiber optic cables throughout the mill network these systems to provide a mill-wide system of control.
Paper mill
A paper mill is a factory devoted to making paper from vegetable fibres such as wood pulp, old rags and other ingredients using a Fourdrinier machine or other type of paper machine.- History :...
located in the city of Sartell
Sartell, Minnesota
Sartell is a city in Benton and Stearns counties in the U.S. state of Minnesota. It is part of the St. Cloud Metropolitan Statistical Area. The population was 15,876 at the 2010 census, making it St. Cloud's most populous suburb and the largest city in the central Minnesota region after St...
in the U.S. state
U.S. state
A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...
of Minnesota
Minnesota
Minnesota is a U.S. state located in the Midwestern United States. The twelfth largest state of the U.S., it is the twenty-first most populous, with 5.3 million residents. Minnesota was carved out of the eastern half of the Minnesota Territory and admitted to the Union as the thirty-second state...
. The mill is owned and operated by Verso Paper.
Watab Pulp and Paper
The original company, Watab Pulp and Paper, was conceived by a group of lumbermenLumberjack
A lumberjack is a worker in the logging industry who performs the initial harvesting and transport of trees for ultimate processing into forest products. The term usually refers to a bygone era when hand tools were used in harvesting trees principally from virgin forest...
from Wisconsin
Wisconsin
Wisconsin is a U.S. state located in the north-central United States and is part of the Midwest. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. Wisconsin's capital is...
and Michigan
Michigan
Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....
and was formed on May 10, 1905 with a capitalization of $200,000. The stock shares were $100 each.
It was the intent to build the mill at Sauk Rapids
Sauk Rapids, Minnesota
As of the census of 2000, there were 10,213 people, 3,921 households, and 2,599 families residing in the city. The population density was 2,234.1 people per square mile . There were 4,017 housing units at an average density of 878.7 per square mile...
at the location of the Sauk Rapids Bridge
Sauk Rapids Bridge
The Sauk Rapids Bridge was a steel spandrel braced arch bridge that spanned the Mississippi River between the cities of St. Cloud and Sauk Rapids in the U.S. state of Minnesota. It was built in 1942 and was designed by the Minnesota Department of Transportation. The bridge consisted of three spans...
, but the owners of the power rights were asking what was felt to be an exorbitant price. Watab Pulp and Paper went further upstream, to Sartell, and for a sum of $1.00 made an agreement with the owners of the existing saw mill to move it from the west side of the Mississippi River
Mississippi River
The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...
to a point just inside the village limits.
The plant started operations with No. 1 paper machine in September, 1905. No. 2 paper machine was built in 1910. The company then produced newsprint
Newsprint
Newsprint is a low-cost, non-archival paper most commonly used to print newspapers, and other publications and advertising material. It usually has an off-white cast and distinctive feel. It is designed for use in printing presses that employ a long web of paper rather than individual sheets of...
until 1930, when the conversion to groundwood book and magazine
Magazine
Magazines, periodicals, glossies or serials are publications, generally published on a regular schedule, containing a variety of articles. They are generally financed by advertising, by a purchase price, by pre-paid magazine subscriptions, or all three...
papers began.
Many changes have taken place since the days when log drives
Log driving
Log driving is a means of log transport which makes use of a river's current to move floating tree trunks downstream to sawmills and pulp mills.It was the main transportation method of the early logging industry in Europe and North America...
down the Mississippi River
Mississippi River
The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...
were common and the paper mill was experimenting using corn
Maize
Maize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...
stalks as a raw material.
During the 1930s, recycled
Paper recycling
Paper recycling is the process of recovering waste paper and remaking it into new paper products. There are three categories of paper that can be used as feedstocks for making recycled paper: mill broke, pre-consumer waste, and post-consumer waste. Mill broke is paper trimmings and other paper...
magazines were a prime source of wood pulp
Wood pulp
Pulp is a lignocellulosic fibrous material prepared by chemically or mechanically separating cellulose fibres from wood, fibre crops or waste paper. Wood pulp is the most common raw material in papermaking.-History:...
. The waste magazines were brought by rail from Chicago
Chicago
Chicago is the largest city in the US state of Illinois. With nearly 2.7 million residents, it is the most populous city in the Midwestern United States and the third most populous in the US, after New York City and Los Angeles...
in bales weighing up to 2,000 pounds. In the “sorting room,” paper clip
Paper Clip
"Paper Clip" is a 1995 episode of The X-Files television series. It was the second episode broadcast in the show's third season. Paper Clip concludes the story regarding the agents' possession of a digital tape containing government secrets on extraterrestrials.- Plot :Continuing from the previous...
s and staples
Staple (fastener)
A staple is a type of two-pronged fastener, usually metal, used for joining or binding materials together. Large staples might be used with a hammer or staple gun for masonry, roofing, corrugated boxes and other heavy-duty uses...
were removed. The waste was then sent to the cookers for deinking and bleaching. The conversion plant operated through the 1930s until the end of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
.
The war years brought other changes to the Sartell mill:
- Women were employed to a greater extent. They sorted magazines and operated the lap machines which enabled the storage of groundwood pulp.
- Sartell manufactured large amounts of paper for the Lend-LeaseLend-LeaseLend-Lease was the program under which the United States of America supplied the United Kingdom, the Soviet Union, China, Free France, and other Allied nations with materiel between 1941 and 1945. It was signed into law on March 11, 1941, a year and a half after the outbreak of war in Europe in...
program after World War II. Some of this paper was sent to RussiaRussiaRussia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
. - During the war, target paper was made for use by the military.
- During this period, the mill also started manufacturing telephone directoryTelephone directoryA telephone directory is a listing of telephone subscribers in a geographical area or subscribers to services provided by the organization that publishes the directory...
, both white and yellow pages.
At the end of the war, the mill closed the finishing operation where paper was sheeted and cut to size. Since that time, all paper manufactured at Sartell has been shipped in roll form.
St. Regis
Plant operations changed immensely. Until 1948, 100-inch wood was handled by hand. Large unloading crews handled the wood from railroad cars to a system of conveyors for building huge storage piles on the river’s edge.
Over the years, many changes had taken place with the mill’s machinery:
- Wooden gears on the paper machine had been changed to metal and plastic
- Fourdrinier bronze wires were changed to polyesterPolyesterPolyester is a category of polymers which contain the ester functional group in their main chain. Although there are many polyesters, the term "polyester" as a specific material most commonly refers to polyethylene terephthalate...
fabrics - Natural sandstoneSandstoneSandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
grinder stones became synthetic carborundumSilicon carbideSilicon carbide , also known as carborundum, is a compound of silicon and carbon with chemical formula SiC. It occurs in nature as the extremely rare mineral moissanite. Silicon carbide powder has been mass-produced since 1893 for use as an abrasive...
Another operation that is no longer performed relates to storing groundwood. In 1934, a large concrete pad was constructed for storing “lapped groundwood pulp. Because of the water-driven groundwood mill, at time of high water availability, excess groundwood was manufactured for use when the water flow was low. Separation of frozen laps was difficult during cold Minnesota winters. When separation was not possible with crowbars
Crowbar (tool)
A crowbar, a wrecking bar, pry bar, or prybar, or sometimes a prise bar or prisebar, and more informally a jimmy, jimmy bar, jemmy or gooseneck is a tool consisting of a metal bar with a single curved end and flattened points, often with a small fissure on one or both ends for removing nails...
, dynamite
Dynamite
Dynamite is an explosive material based on nitroglycerin, initially using diatomaceous earth , or another absorbent substance such as powdered shells, clay, sawdust, or wood pulp. Dynamites using organic materials such as sawdust are less stable and such use has been generally discontinued...
was used. The lapped groundwood pulp was then brought in to the mill and placed into beaters for repulping and use.
In 1957, No. 1 paper machine had a major rebuild. The same was done the following year on No. 2 paper machine. Both machines were sped up with the addition of new steam turbine drives and new headboxes.
The mill had one of the earliest supercalenders in the industry. In 1960, No. 1 and No. 2 supercalenders were installed.
Since the 1960s, uncoated supercalendered grades of paper have been manufactured. In the past twenty years, basis weight of these papers has been reduced from a 43 pound sheet that was used in Family Circle
Family Circle
Family Circle is an American women's magazine published 15 times a year by Meredith Corporation. It began publication in 1932 as a magazine distributed at supermarkets such as Piggly Wiggly and Safeway. Cowles Magazines and Broadcasting bought the magazine in 1962. The New York Times Company bought...
magazine to, in some instances, as low as 26 pound.
St. Regis was one of the first companies in the area to install equipment for fly ash removal and wastewater treatment facilities. The wastewater treatment facility was one of the first in the papermaking industry
Pulp and paper industry
The global pulp and paper industry is dominated by North American , northern European and East Asian countries...
; much experimentation has been done to improve the operation. Sartell won an Izaak Walton League award for clean water related to these efforts. The mill has also been commended seven times by the Minnesota Pollution Control Agency since 1985 for excellent wastewater treatment facility operation and effluent quality.
The mill has also been a pioneer in burning bark and wastewater
Wastewater
Wastewater is any water that has been adversely affected in quality by anthropogenic influence. It comprises liquid waste discharged by domestic residences, commercial properties, industry, and/or agriculture and can encompass a wide range of potential contaminants and concentrations...
sludge, very significant with the solid waste considerations of today. The bark burning system went into operation in 1961 and the secondary wastewater treatment system started up in April 1973.
Although the No. 3 paper machine project of 1982 is referred to as an expansion, it consisted almost of an entire mill replacement or rebuild. Virtually all areas were affected, except existing paper machine and supercalender areas. Existing water supply systems, filtration systems, shops, stores, primary electrical, and some effluent treatment facilities were all replaced. April 2000 brought an upgraded gapformer installation, including a headbox which was replaced and updated with new dilution control technology.
No. 1 and No. 2 paper machines operate at 1,950 feet per minute and 1,880 feet per minute respectively and produce about 280 tons of publication grade paper per day. With the addition of No. 3 paper machine, currently operating at 4,150+ feet per minute, another 600 tons are produced daily.
Champion International
As a result of a giant corporate merger in 1984, St. Regis Corporation was merged with Champion International Corporation, creating leadership in the markets of coated and uncoated publication grades and newsprint to the company’s already established positions in free-sheet paper for printing, writing, converting and business.International Paper
In June 2000, Champion was purchased by International Paper making it the world’s largest paper and forest products company.Woodyard and Woodroom
All of the wood is received in 8-foot lengths from the forests of Minnesota, Wisconsin and Michigan. 60% is received by rail and 40% is received by truck. Wood is unloaded to the yard which has a storage capacity of 5,000 cordsCord (unit of volume)
The cord is a unit of measure of dry volume used in Canada and the United States to measure firewood and pulpwood. A cord is the amount of wood that, when "ranked and well stowed" , occupies a volume of...
.
The woodroom consists of two independent processing lines with a common bark
Bark
Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines and shrubs. Bark refers to all the tissues outside of the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner...
system. Each line is designed to produce 100 cords per shift of high quality, bark-free chips.
Fir
Fir
Firs are a genus of 48–55 species of evergreen conifers in the family Pinaceae. They are found through much of North and Central America, Europe, Asia, and North Africa, occurring in mountains over most of the range...
is fed through the softwood
Softwood
The term softwood is used to describe wood from trees that are known as gymnosperms.Conifers are an example. It may also be used to describe trees, which tend to be evergreen, notable exceptions being bald cypress and the larches....
line and debarked in a 12-foot by 68-foot debarking drum. Equipment has been added for log washing and deicing prior to the drum to facilitate debarking. After debarking, the wood flows through a log inspection and sorting system where individual sticks may be recycled to the drum. Properly debarked logs are directed to a 12-knife Carthage chipper. Chips are screened and conveyed to chip storage bins.
The aspen
Aspen
Populus section Populus, of the Populus genus, includes the aspen trees and the white poplar Populus alba. The five typical aspens are all native to cold regions with cool summers, in the north of the Northern Hemisphere, extending south at high altitudes in the mountains. The White Poplar, by...
, or hardwood
Hardwood
Hardwood is wood from angiosperm trees . It may also be used for those trees themselves: these are usually broad-leaved; in temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen.Hardwood contrasts with softwood...
, line is similar to the softwood line except that logs are debarked in a Nicholson mechanical ring debarker. Wood is chipped separately and stored in a 400-cord chip bin.
TMP Plant
The TMP plant is designed to produce up to 550 tons of pulp per day. The plant has two lines, each with three stages. Each of the six refiners are driven by two motors. The total horsepower per refining line is 32,500. The primary refiner is a pressurized unit and the secondary and tertiary refiners operate under atmospheric pressure. Chips are washed, steamed under pressure, and refined in the first stage. The pressurized refiner discharges into a cyclone which separates the pulp from the steam and supplies the pulp to the second-stage refiners. Recovered steam goes to the heat recovery system.The TMP pulp discharged from the tertiary refiner is treated for latency removal, series screened, cleaned, thickened, and stored in two medium density storage tanks. Screened rejects are further refined, screened, and cleaned before storage. The unbleached TMP is recovered from storage and bleached to brightness levels in the bleach plant.
Kraft Preparation
Bleached kraft is received in bales from CanadianCanada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
mills. Fork trucks
Forklift truck
A forklift is a powered industrial truck used to lift and transport materials. The modern forklift was developed in the 1920s by various companies including the transmission manufacturing company Clark and the hoist company Yale & Towne Manufacturing...
deliver a six-bale stack to bale handling equipment for destacking and dewiring. A dewiring system, the first automatic one in the industry, dewires bales before they are dumped from the conveyor to the pulper; the slush pulp is then pumped to a soak chest, refiners, and storage tank.
Coating Preparation
The process is based on the conversion of starch in the presence of clayClay
Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...
. Coating ingredients are mixed in a slurry makedown tank, screened, and pumped continuously through various stages for enzyme addition and cooking.
Coating is discharged into a flash tank where flash steam is directed to a condensing chamber where heat is recovered as hot water. Finished coating is stored for eventual use on the paper machines.
No. 3 Paper Machine
The initial planning for No. 3 began early in 1978. Decisions were made regarding the design at that time using experience gained from the operation of No. 5 paper machine at Bucksport, MaineMaine
Maine is a state in the New England region of the northeastern United States, bordered by the Atlantic Ocean to the east and south, New Hampshire to the west, and the Canadian provinces of Quebec to the northwest and New Brunswick to the northeast. Maine is both the northernmost and easternmost...
. Both machines are the same size and general configuration. The fabric width is 314 inches, design speed was 3,500 feet per minute, and the maximum salable trim is 280 inches. The design basis weight was 34# and at design speed, the machine would produce 480 tons per day. Modifications have since been made and No. 3 paper machine now operates at 4,150+ feet per minute, producing 600 tons of salable paper per day.
A Voith dilution control headbox was selected to improve the ability to control profile and formation.
A gap former was chosen to improve sheet formation and paper quality essential to raw stock manufacture.
The press section is a Beloit twinver with an inclined straight-through, grooved third press. This type of press section was selected because of its cleanliness during operation, efficient water removal capability, and successful operation in the past.
The main dryer section consists of 43 six-foot dryers split into four sections.
The two-roll machine calender is equipped with two variable crown rolls and heating capability for caliper control.
The Beloit short-dwell nip coaters and later EXCEL Coaters in 1998 were included to apply five pounds of coating to each side of the sheet. Conservation measures have also been taken in reclaiming coating and recycling it to the coated broke system for recovery.
Paper Finishing
From the paper machine reel, the paper is trimmed on a rereeler prior to being sent to two ten-roll Beloit supercalenders. The supercalenders impart a smooth, glossy finish to the paper’s surface, improving appearance and print quality.The paper is wound onto individual rolls on a Jagenberg vari-top single drum winder. The maximum design speed of this unit is 8,500 feet per minute. This winder is also highly automated to maximize productivity.
Roll Wrapper
The paper from the entire mill is wrapped by a low profile, semi-automated roll wrapper system, averaging 750 rolls per day. Roll tickets use a barcodeBarcode
A barcode is an optical machine-readable representation of data, which shows data about the object to which it attaches. Originally barcodes represented data by varying the widths and spacings of parallel lines, and may be referred to as linear or 1 dimensional . Later they evolved into rectangles,...
for identification and inventory control.
Warehouse
The paper warehouse can store up to 5,000 tons of finished paper and fifteen railroad cars, ten for loading paper and five for unloading kraftKraft process
The kraft process describes a technology for conversion of wood into wood pulp consisting of almost pure cellulose fibers...
, can be “spotted” inside the building. This amount of storage is necessitated with this seasonable type of business.
Power Plant
SteamSteam
Steam is the technical term for water vapor, the gaseous phase of water, which is formed when water boils. In common language it is often used to refer to the visible mist of water droplets formed as this water vapor condenses in the presence of cooler air...
is generated in a Babcock and Wilcox stoker-fired coal
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...
boiler with a capacity of 270,000 pounds of steam per hour. The boiler is designed to burn a combination of coal, bark, wastewater sludge, and tire chips. Steam is distributed to process at 450, 150, and 50 psi.
A Brown Boveri double-extraction back-pressure turbine (manufactured in St. Cloud
St. Cloud, Minnesota
St. Cloud is a city in the U.S. state of Minnesota and the largest population center in the state's central region. The population was 65,842 at the 2010 census. It is the county seat of Stearns County...
) has also been installed. The unit can generate 20.8 MW at maximum, but the actual generation is dictated by steam usage.
The primary fuel is low-sulfur
Sulfur
Sulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...
Kentucky
Kentucky
The Commonwealth of Kentucky is a state located in the East Central United States of America. As classified by the United States Census Bureau, Kentucky is a Southern state, more specifically in the East South Central region. Kentucky is one of four U.S. states constituted as a commonwealth...
coal, delivered by truck. The coal is unloaded into a concrete lined storage area. Belt conveyors transport the coal to the crusher/transfer house, then to the boiler bunker.
The mill uses and returns (cleaner than the river itself) ten million gallons of water per day. Mill effluent is treated in the primary clarifier for solids removal. An activated sludge aeration basin with secondary clarifier is used for BOD reduction before discharge to the Mississippi River
Mississippi River
The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...
. Sludge from the clarifiers is dewatered on a belt filter
Belt filter
The belt filter is an industrial machine, used for solid/liquid separation processes, particularly the dewatering of sludges in the chemical industry, mining and water treatment...
press and a screw press. The thickened sludge is mixed with bark and fed to the boiler for incineration.
Mill Computer Systems
Automation technology is critical to the operations of the Sartell mill. Many computer based systems work together to account for and to improve the quality of mill products.Some of them are:
- The process control systems constantly monitor and control thousands of process variables such as pressure, flow, temperature, and tank levels in the area of pulp production, stock preparation, coating and additives, electrical and steam generation and effluent treatment.
- The on-machine scanning systems measure and control the standards of the paper produced on each machine. Every grade of paper is made to conform to measurements such as moisture, basis weight, coating weight and caliper.
- PLC (Programmable Logic Control) Systems (Allen Bradley, Reliance) control the stopping, starting, and speed control of most mill equipment including the speed of, and draw between each section of the paper machine.
- The product tracking system monitors the production from the paper machines to customer delivery which includes inventory, manifesting, billing, and shipping.
- The corporate mainframe systems, located in Plano, Texas, provide for purchasing, accounting, payroll, storeroom, and human resource functions, along with customer order entry.
- Local Information Systems provide mill personnel with timely information from mill systems, and the tools to perform analysis on, graphically display, generate reports from, and store this information.
- More than 300 networked personal computers provide access to most of the mill’s systems and databases. These computers also provide e-mail, scheduling, internet access, as well as other desktop applications.
High speed fiber optic cables throughout the mill network these systems to provide a mill-wide system of control.