Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D9/00—Priming; Preventing vapour lock
  • F04D9/001—Preventing vapour lock
  • F04D9/002—Preventing vapour lock by means in the very pump
  • F04D9/003—Preventing vapour lock by means in the very pump separating and removing the vapour
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D7/00—Pumps adapted for handling specific fluids, e.g. by selection of specific materials for pumps or pump parts
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D3/00—Axial-flow pumps
  • F04D3/02—Axial-flow pumps of screw type

Definitions

• the present invention relates to a device for pumping a moist pulp and may be used in the wood-pulp and paper industry for conveying a highly concentrated pulp.
• Concentrations of the pulp in the range of 8 - 16 % are usually called as mean concentrations, or concentrations "MC”.
• Devices used to convey the pulp with such concentrations are usually called as "MC" pumps.
• the above pump comprises a spiral body including a feed hopper and five working zones: A - a zone for fluidizing the pulp by means of a rotor which generates intensive shearing forces; B - a zone for evacuating air a high content of which in the "MC" pulp makes its delivery by a centrifugal pump impossible; C - a zone where separation of fibres transferable with air takes place; D - a zone for evacuating a fibre-free air; E - a zone where delivery of the pulp by a pump rotor takes place.
• all rotors are mounted on one and the same shaft which permits using a pump having one rotor as a conventional centrifugal pump.
• the pulp delivered from the feed hopper is thinned, that is to say, is separated into individual fibres, thereupon the use of a centrifugal pump becomes possible.
• Air is separated from a thinned pulp in the Zone B and is evacuated through the Zone D by means of a small-sized vacuum pump. During the entire process for pumping, the pulp remains in the thinned state.
• the closest prior art has been described in a device designed to deliver a pulp with a mean concentration ol 8 - 15 % by weight, comprising a body with pipe connections for the pulp delivery and evacuation, external and internal worm feeders and an impeller coaxially mounted on the internal worm feeder.
• the internal worm feeder is provided with a means for evacuating air from the pulp which is made in the form of a channel inside a shaft having a perforation as viewed from the impeller [see USSR Inventors' Certificate No. 1463332, B 01 F 7/04, 1989].
• the present invention is made in order to solve the above problems included in the prior arts, and an object of this invention is to provide a special device which enables pumping over a moist pulp of a high concentration (16 - 90 %) with maximum efficiency at different sectors of production lines of paper making industry.
• a pump for conveying a moist pulp which comprises a body having a hopper for receiving a pulp; a replaceable pipe connection in which a worm feeder is coaxially located; a check valve mounted as viewed from a pulp outlet from said pipe connection; and a mixing chamber for mixing the pulp with a carrying agent; the chamber is coupled with said pipe connection and fitted with a means for supplying the carrying agent; wherein an adjustable gap is provided between the worm feeder end and the check valve; on the surface of the pipe connection, on the level of the last flight of said worm feeder there are provided longitudinal through splines having a width of about 0.2 - 1.0 mm, a length of not more than a lead of the last flight of said worm feeder, and a total open [clear] area of from 0.5 ⁇ S to A S, where ⁇ S means the difference between an inner sectional area of the pipe connection and a sectional area of the worm feeder rod.
• the proposed pump differs from the prior art pump in that a body of the pump is provided with a replaceable pipe connection in which a worm feeder is coaxiallv located: a check valve mounted as viewed from a pulp outlet from said pipe connection; and a mixing chamber for mixing the pulp with a carrying agent; said chamber is coupled with said pipe connection and fitted with a means for supplying the carrying agent; wherein an adjustable gap is provided between the worm feeder end and the check valve: said means for evacuating air is made in the form of longitudinal through splines being located on the surface of the pipe connection, on the level of the last flight of said worm feeder and having a width of about 0.2 - 1.0 mm, a length of not more than a lead of the last flight of said worm feeder, and a total open area of from 0.5 ⁇ S U_> ⁇ S, where ⁇ S has the above defined meanings.
• Through splines provided on the surface of the pipe connection are intended to be used to evacuate air which is displaced from the pulp in the process of its compaction in a space between the last flight of the worm feeder and the check valve.
• dimensions of the splines and a total open area are chosen such that, on the one hand, a possibility of squeezing-out the pulp through the splines (at the expense of a limitation on maximal sizes and areas) be ruled out and, on the other hand, a maximally efficient air evacuation from a compressed pulp (at the expense of limitation on maximal sizes and areas) be attained.
• a lead of the worm feeder flight may be both constant and variable, depending upon a particular fibre type and technological features of the process in which the present conveying device is implemented.
• Figure 1 is a sectional view of a pump; and Figure 2 shows A - A section of Figure 1.
• the pump comprises a body 1 having a hopper 2 for receiving a pulp; a replaceable pipe connection 3 and a mixing chamber 4 for mixing the pulp with a carrying agent.
• the pipe connection 3 is provided with a worm feeder 5 which is coaxially located therein.
• a check valve 6 is mounted as viewed from a pulp outlet from said pipe connection.
• the worm feeder has two zones - a loading zone 5a located within said feed hopper and a delivery zone 5b located directly in the pipe connection 3.
• the worm feeder 5 is driven into rotation by means of a motor drive 7.
• the mixing chamber 4 is provided with a means 10 for supplying a carrying agent. This means may be made in the form of a supply pipeline.
• the pump body is disposed on special supports 1 1.
• the check valve 6 opens up and a portion of a fibrous material enters the mixing chamber 4.
• a carrying agent (usually, it is air or its mixture with another gas) supplied under a high pressure into the mixing chamber 4 through a supplying means 10 breaks up the pulp into separate fibres. From the mixing chamber 4, the pulp divided into separate fibres is fed, by means of the carrying agent, via a pipeline (not shown in the drawing) to any section of the production line.
• a gap between the last flight of the worm feeder 5 and the check valve 6 is easy to adjust when mounting the pipe connection 3, which enables formation of a "pulp plug" of different thickness, for example from about 10 to 50 mm, depending on a particular type of raws and technological features of the process. Just the same factors influence the choice of optimal dimensions of through splines and an open area. The selection of an optimal thickness of a "pulp plug", through spline dimensions and an open area permits pumping over a moist pulp with maximum efficiency.
• the use of the proposed conveying device permits reduction in energy expenditures to pump over a moist pulp due to the fact that the water content in this pulp may be decreased from 84 % to 10 % (which corresponds to the pumping over a moist pulp at the concentration of an absolutely dry substance of from 16 % to 90 % by weight).
• the proposed pump may be installed at different sectors of production lines of paper-making industry to convey a highly concentrated pulp at long distances with the result that a need for using a system for the pulp dilution with water is ruled out, a total quantity of waste waters and energy expenditures to treat thereof are reduced.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Paper (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=20166556

Family Applications (1)

Country Status (10)

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• 1995
  • 1995-04-12 RU RU9595105344A patent/RU2083879C1/ru active
• 1996
  • 1996-04-10 JP JP8530936A patent/JPH11503508A/ja active Pending
  • 1996-04-10 BR BR9604898A patent/BR9604898A/pt not_active IP Right Cessation
  • 1996-04-10 KR KR1019970707210A patent/KR19980703810A/ko not_active Application Discontinuation
  • 1996-04-10 CA CA002217724A patent/CA2217724A1/en not_active Abandoned
  • 1996-04-10 AU AU57824/96A patent/AU5782496A/en not_active Abandoned
  • 1996-04-10 CN CN96193222A patent/CN1185824A/zh active Pending
  • 1996-04-10 WO PCT/RU1996/000090 patent/WO1996032591A2/en not_active Application Discontinuation
  • 1996-04-10 EP EP96914477A patent/EP0820563A2/de not_active Withdrawn
• 1997
  • 1997-10-10 NO NO974700A patent/NO974700L/no unknown

Non-Patent Citations (1)

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