Atlas Vacuum provides liquid ring vacuum pumps and compressors known for their simple and reliable structure, requiring minimal maintenance. They are widely used in original Siemens engineering vacuum systems, paper machine dewatering, and pump replacement. We also offer OEM services. By utilizing liquid ring vacuum pumps, paper production costs can be reduced while enhancing paper quality.

Black Liquor Evaporation

In pulp mills, black liquor evaporators are utilized to concentrate the black liquor generated during the pulp cleaning process. This allows these liquids to be recycled back to the recovery furnace to reclaim chemical agents for reuse in pulp production.

Coarse pulp washing machine

The Coarse Pulp Washer is a typical horizontal drum filter used to remove pulp chemicals ("black liquor") from pulp stock before bleaching or other raw material preparation processes in papermaking. The drum chamber can generate a vacuum. As the drum rotates in the pulp stock, the vacuum helps adhere the stock to the outer surface of the drum and aids in removing (washing) the black liquor from the stock.

Lime slurry and filter

Lime mud filters in pulp mills are used to recover lime from the white water clarification process. Similar to coarse pulp washers, lime mud filters are typical horizontal drum filters. The interior of the drum can create a vacuum. As the drum rotates in the lime mud slurry, a lime cake forms on the outer surface of the drum. It is then scraped off and reused in the white water process.

Sediment filter

Precipitate filters in pulp mills are used to filter out non-combustible suspended particles, partially burned carbon particles, iron compounds, and insoluble furnace body fragments from the "green liquor" before they are burned. The precipitate filter is a typical horizontal drum filter. The interior of the drum can generate a vacuum, which is used to extract particles from the green liquor.

Vacuum dehydrator

Vacuum dehydrators are used for dewatering during the raw material preparation stage to increase the concentration of the material. These dehydrators are typical horizontal drum filters designed to remove water proportionally from the pulp, thereby increasing the concentration of the raw material.

Raw material and white water degassing system

The raw material and white water degassing system is used during the raw material preparation stage to remove air carried by the raw material or from dilution water before it enters the pulper. This system is crucial because removing air from the papermaking material prevents the formation of pinholes on the paper, which significantly affects print quality, mechanical properties, and overall paper quality.

Mixing box compressor/vacuum pump

The pulper chest compressor/vacuum pump is utilized inside the "headbox" of the pulper to generate pressure/vacuum above the pulp level (or "stock chest") in the headbox, thereby controlling the discharge rate of the stock (or "jet" velocity) to the maximum extent. The pump typically functions as both a vacuum pump and compressor through a series of valves. It creates vacuum or pressure in the headspace volume above the stock chest to control the head pressure in the headbox.

Suction box

The suction box is a stationary device located in the forming section of the paper machine, used for dewatering directly from the pulp. There are typically 2-10 suction boxes on a paper machine, often connected to a common header. Due to the substantial dewatering requirements, a pre-separator is installed between the suction box and the vacuum box, with a liquid ring pump employed to generate vacuum inside the suction box.

Suction roll

The suction roll, often situated towards the end of the forming section, serves as a crucial dewatering component in papermaking machines. It is considered one of the most important dewatering sections of the paper machine. As the paper exits the suction roll and enters the press section, its dryness affects the dewatering performance of the press section and the steam consumption in the drying section. The suction roll, which remains stationary, features a rotating porous shell. It may have one or two vacuum zones.

Suction roll and transfer roll

The suction roll extracts the paper from the wire mesh at the forming section and guides it into the press section. Subsequently, in the press section, the transfer roll moves the paper from one felt to another. These processes do not involve significant dewatering but help remove a small amount of water from the paper.

Vacuum pressing

Vacuum pressing is a mechanical method used to extract moisture from paper. In the pressing section, rolls with surfaces made of granite and hard rubber come into close contact, forming a "pressing zone." A typical paper machine may have 1-3 "pressing zones." As the paper passes through these zones, moisture is pressed out and absorbed into the pressing felts, which serve as the transportation medium and cushion for the paper. In the dewatering process, both vacuum and non-vacuum rolls are used in the pressing section.

Felt Suction Boxes

During pressing in the pressing section, the press fabric (or "felt") carries a mixture of water, chemicals, paper stock, dirt and fillers, sticky residues generated during the papermaking process ("pitch"), and adhesive residues from recycled paper ("stickies"). Since each piece of felt is a continuous loop, moisture and contaminants must be removed before the next pressing cycle begins. Felt suction boxes are stationary suction boxes that span the width of the felt and absorb the water and contaminants accumulated in the felt during pressing. Each piece of felt has two felt suction boxes. Pre-separation treatment is necessary when using felt suction boxes to prevent carried water from entering the vacuum pump.

Blow Box

In the pressing section, there are some "open" press zones where the paper is not supported before entering the zone, and airflow may cause the paper to flutter, fold, or tear. The blow box is fixed and positioned upstream of the press zone to create a vacuum before the paper enters. Since the blow box fabric is used for dewatering, pre-separation treatment is not necessary.