Valmet’s PowerFloat Plus is a proprietary retrofit replacement for dryer bars in an air floatation dryer. Air floatation dryers are used to dry coating added to the surface of a paper sheet. They are used where non-contact drying is required because the coating would stick to a conventional dryer drum.

PowerFloat Plus dryer bars can be retrofitted to existing systems regardless of the manufacturer. PowerFloat Plus nozzle design delivers more heat and provide better support to the coated sheet over a wider area compared to foil-type and float-type nozzles. The result is greater heat transfer efficiency, better sheet support, more even drying, and reduced maintenance.

PowerFloat Plus can be installed without changing the dryer layout. Rebuilding an air dryer with these nozzles can increase evaporation capacity by 25% compared to float-type nozzles and over 50% compared to foil-type nozzles. In single-sided air dryer applications, replacing impingement nozzles can increase heat transfer efficiency up to 20%.

Infrared (IR) dryers are used on paper machines and paper coaters to ensure consistent moisture across the width of the sheet and to dry paper coatings. High efficiency dryers incorporate innovative design features compared to conventional electric IR dryers including:

• Integrated gold-plated reflectors to maximize infrared radiation reaching the material. These reflectors also do not require cleaning.
• Hydroxyl-free quartz lamps which absorb very little IR and cool to the touch within seconds of shutting off.
• Scouring of the moisture-saturated air from the media surface to increase the rate of drying.

Side entry agitators are commonly used in the paper industry in stock blending and mixing tanks. Most agitators employ “marine” type impellers. These are basically boat propellers, with the pitch and diameter selected for the specific application.

High efficiency units are custom-built based on the material being mixed and the size and geometry of the tank. This maximizes mixing while minimizing required motor power compared to all-purpose impeller designs. To install, only the impeller blades and hub are replaced, and the shift, gearbox, and motor are typically reused.

The motors on typical stock tank agitators range from 10 – 200 Horsepower.

Many industrial facilities and municipalities have waste treatment facilities to treat organic wastes. Traditional treatment systems use aerobic processes to separate organics from the waste stream. Some facilities choose to employ anaerobic treatment systems. When a site implements an anaerobic treatment system, biogas is produced. This biogas can be used to offset a facility’s natural gas and/or electrical usage. However, to reliably utilize biogas, it must be cleaned. Contaminants can vary widely by the source of waste material being anaerobically treated. The need for removal of contaminants may also vary. This is required whether the gas is combusted in a process boiler or as fuel for a combustion engine/generator. This technology is a system that produces clean biogas that can be deployed on-site.

Yankee dryers are large (diameters between twelve and thirty feet) rotating drum pressure vessels that utilize steam to dry paper. Yankee dryers are commonly used for producing tissue and machine glaze (MG) paper.

Traditional Yankee dryers are manufactured from cast iron. Cylinders are cast separately from the heads, which are affixed with many bolts. Yankee dryers fabricated from rolled and welded steel are a relatively recent development. Steel Yankee dryers offer several advantages over conventional (cast iron) units including significant energy savings.

Benefits

• Improved Heat Transfer – derived from reduced shell thickness and the ability to use higher pressure steam.
• Insulated Heads – not feasible on cast iron dryers. Reduces heat loss by 2% - 3%.
• Steam Heating versus Gas-Fired Air Heating - increased heat transfer reduces the need for gas-fired air drying leading to boost in overall efficiency of 10% or more.
• Edge Effect – thinner steel and no bolts provide a more even moisture profile across the entire sheet width. This reduces the needs for correction methods that require more energy.
• Safety – cast iron gets more brittle as it ages, weakening the cylinder. Steel dryers have no bolts that can fail and reduce the need for non-destructive examination. Defects can be readily fixed in the steel dryer.

A Heat of compression (HOC) dryer is a sub-type of desiccant dryer. It utilizes the heat generated during compression to dry compressed air. HOC is the most energy efficient air dryer, consuming virtually no energy. Heat of compression dryers can be utilized with most oil-free air compressors. They cannot be used with oil-flooded compressors. Both twin tower and rotary units are available.  As is the case for all desiccant dryers, HOC can provide -40o F dewpoint air.

A typical centrifugal pump used in pulp or paper processing utilizes a single mechanical seal to prevent leakage of process fluid out of the rotating shaft. In most cases, “flush” water is applied to seal faces to keep them clean and cool. This seal water ends up in the process fluid.

A Closed Loop Seal Flush System (API Plan 53) eliminates seal water intrusion by using a pressurized barrier fluid circulating in the outboard seal of dual seal configuration. Circulation is maintained by using a pumping ring in running condition and with a thermosiphon effect in stand-still condition.

The system utilizes a seal pot that is automatically filled and pressurized by a connected water supply line through an in-line filter, which is regulated to the optimum pressure to support the seal.

In cases where the process fluid needs to be heated, seal water that infiltrates process fluid will also need to be heated. This system eliminates infiltration and, with it, the energy needed to heat it. CTP personnel measured seal water usage for 200 single seal applications and found average usage to be about 3 GPM per seal. Therefore, each application of API Plan 53 will reduce plant water usage by about 1.5 million gallons per year, assuming 8,500 hours of annual operation.

Thermocompressors recirculate steam or boost lower-pressure steam for reuse in a variety of process applications in industries including:

• Pulp and paper
• Petrochemical
• Food processing
• Desalination
• Specialty chemical production

Thermocompressors are designed to accurately mix lower-pressure steam with higher-pressure steam. The higher-pressure motive steam entrains the lower-pressure steam and increases its pressure.

High-efficiency thermocompressors are designed using computational fluid dynamics (CFD) modeling to provide entrainment ratio improvements of up to 25 percent over conventional units. A higher entrainment ratio means that more “low-pressure” steam and less “high-pressure” steam are used. Installations may result in Therm and/or kW savings. 

Paper machines utilize suction rolls in various positions to remove water from the sheet or assist in sheet transfer. The outer shell rotates with the paper. A stationary inner portion provides vacuum to a designated segment of the radius. The portion under the vacuum must be sealed from the rest of the roll. The conventional sealing system uses fan-type spray nozzles to lubricate and help seal the sealing strips. These nozzles can be prone to plugging and use excessive amounts of water because they need to provide lubrication and sealing to multiple strips.

With HydroSeal, the lubricating water is distributed continuously over the entire width of the sealing strip and thus allows its surface to continuously be covered with a homogeneous film of lubricating water. The efficient feed substantially reduces the amount of lubricating water required. Moreover, this new design prevents remoistening of the paper web and also improves the cross-directional moisture profile.

Trials carried out in the field on our customers' machines demonstrated that, by using HydroSeal lubricating, water consumption could be reduced by up to 87 percent. Specific energy consumption was cut by 9 percent due to reduced drive friction load.

Each installation is evaluated based on the amount of water needed versus baseline, where the lubrication water ends up, and the expected drive load reduction.

Many Paper machines utilize dissolved air floatation save-all units (DAF) to purify whitewater. By design, suspended solids are floated to the surface using air bubbles. These designs inject compressed air into the discharge flow of a large volume pump, which occurs under pressure at somewhere between 40 and 60 psi. Pressure is then dropped to atmospheric and air bubbles are produced by pressure reduction. The Hydro-sparger produces bubbles by drawing atmospheric air into an inductor. The hydro-sparger uses significantly less energy because it does not use high pressures or compressed air.

The RotoFlex resource recovery strainer is used to effectively and efficiently reclaim white water, heat, chemicals, and fiber from a variety of paper and pulp mill applications, including DAF filtrate, save-all water, and seal pit water.

Gravity strainers are the current best practice. Unfortunately, many gravity strainers have been abandoned due to operational issues. Traditional gravity strainers utilize a screen that is almost horizontal and a motorized rotating shower to clean the screen. This often leads to a loss in effectiveness over time.

RotoFlex operates with a different and superior technical approach. The fluid to be filtered is supplied to a distribution header that feeds six stationary distribution header arms mounted parallel to the screen. A series of uniquely-designed slots on each header delivers the feed at low pressure (less than 6 psig/1.4 bar) uniformly around the screen surface area. The impact force from the distribution slots combined with the precisely-angled flow results in rotation of the screen assembly. Water that passes through the filtration medium collects and drains from the bottom of the unit. The retained solid material slides down the angled screen to the center where it exits the system to a user-supplied collection tank.

RotoFlex uses a unique method of filter media cleaning to keep the filter medium open and to flush contaminates from the surface. This results in the following benefits:

• Recovery of water, heat, chemical, and fiber
• No electrical motors or continuous shower water required
• Continuous operation through system upset conditions
• High volume capacity

Foundries that utilize green sand molding techniques mix sand and a suitable bonding agent, mostly clay, in a mullor or mixer. The mixture is moistened with water to develop strength and make the aggregate suitable for molding. The mixture is then mulled for a specified period of time. This “green sand” is typically deployed in a system of frames or mold boxes known as flasks. The mold cavities are formed by compacting the green sand mixture around models, or patterns. Molten metal is then poured into the molds to create castings. Once the castings cool, the green sand is separated from the metal and the sand is recycled to be used again.

Traditional mulling practice is to mull the sand for a predetermined amount of time. Traditional thinking was that sufficient mulling time was needed to cover the varying incoming sand conditions.

This new technology utilizes high-speed data acquisition systems to monitor real-time energy usage of foundry batch mullors to determine when during the mixing cycle the clay/sand mixture achieves its maximum strength. A control algorithm is used to sense the maximum strength during each mixing cycle and end the mixing cycle at that point. Mixing the clay/sand mixture past the point where maximum strength is achieved actually results in loss of strength. Operating in this real-time energy control mode can result in energy savings of 15 to 35 percent.

SpyroCor is a patented, high-tech ceramic (silicon-graphite) insert for gas-fired radiant tube heaters used in metal heat-treating furnaces that reduce the energy demands of the process by 10% to 20%. Energy savings were confirmed through several M&V studies.