Novel chemical pulping system

Abstract

A novel chemical pulping system is characterized by comprising a presoaking tower, a wood chip pump arranged at the rear end of the presoaking tower, a cooking tower arranged at the rear end of the presoaking tower, a medium-concentration mill arranged at the rear end of the cooking tower, a blow-off pot arranged at the rear end of the cooking tower, a sand remover feeding pump arranged at the rear end of the blow-off pot, and two medium-concentration mills added from a cooking line, various raw materials can be prepared, and various kappa ranges can be selected; and a residue-pulp mill is arranged when the screened pulp residue wood sections are treated to treat and recover the pulp residue wood sections, so that zero emission of harmful solid wastes is realized, the pulping yield is increased, the environment is protected, the benefit is further increased, the selectivity of raw material types is relatively strong, the method can be suitable for cooking various raw materials, the kappa number range of cooking is relatively wide, the energy consumption is saved, and the method is suitable for industrial production. Solid wastes such as slurry residues and wood knots are low in output or are not produced, so that environmental pollution is reduced, and the method is more environment-friendly.

Description

Technical Field

[0001] The utility model relates to the technical field of pulping and papermaking, in particular to a novel chemical pulping system. Background Art

[0002] A method of making pulp by treating raw materials with chemical agents. This method uses fiber plants, mainly wood and grass stems, as raw materials, and uses a chemical agent that can selectively react with the lignin contained in the raw materials to remove most of the lignin, and make the single fibers in the raw materials fully loose and separated into pulp with high cellulose purity. There are two types of pulping commonly used in industrial production: alkali pulping and sulfite pulping. The existing chemical pulping system generally sends wood chips to the screening section for screening and the bleaching section for bleaching after the wood chips are sent to the cooking section. Either only a relatively single raw material can be cooked, a mixture of one species of coniferous wood or a maximum of two wood chips in broad-leaved wood, the raw material is relatively single and the selectivity is weak, which is not conducive to the current shortage of wood chips; or only a single kappa with a low and narrow kappa value range can be cooked, which is not conducive to saving energy and facing changes in market demand; the existing chemical pulp production system generally produces solid waste such as pulp residue or wood knots, causing certain environmental pollution. In order to solve the above problems, a new chemical pulping system is proposed. Utility Model Content

[0003] According to the above existing technical problems, the utility model provides a novel chemical pulping system, characterized in that it comprises a prepreg tower, a wood chip pump is arranged at the rear end of the prepreg tower, a cooking tower is arranged at the rear end of the prepreg tower, a medium-consistency mill is arranged at the rear end of the cooking tower, a spray pot is arranged at the rear end of the spray pot, a desander feeding pump is arranged at the rear end of the desander feeding pump, a first desander is arranged at the rear end of the desander feeding pump, a de-knot machine is arranged at the rear end of the first desander, a section of pressure screen is arranged at the rear end of the first desander, a vacuum pulp washer is arranged at the rear end of the section of pressure screen, a double-roll feeding riser is arranged at the rear end of the vacuum pulp washer, a double-roll feeding riser is arranged at the rear end of the double-roll feeding riser, a double-roll pulp washer feeding pump is arranged at the rear end of the double-roll pulp washer, a double-roll pulp washer is arranged at the rear end of the double-roll pulp washer feeding pump, a double-roll pulp washer is arranged at the rear end of the double-roll pulp washer, a double-roll conveying screw is arranged at the rear end of the double-roll conveying screw, a medium-consistency pulp tower feeding riser is arranged at the rear end of the medium-consistency pulp tower feeding riser, and a medium-consistency pulp tower feeding pump is arranged at the rear end of the medium-consistency pulp tower feeding riser;

[0004] Furthermore, a first medium-concentration slurry tower is arranged at the rear end of the medium-concentration slurry tower feeding pump, a second medium-concentration slurry tower is arranged at the rear end of the medium-concentration slurry tower feeding pump, the first medium-concentration slurry tower is connected to a slurry mixing tank via a first slurry delivery pump, the second medium-concentration slurry tower is connected to a slurry mixing tank via a second slurry delivery pump, the rear end of the slurry mixing tank is connected to a low-concentration mill via a low-concentration mill feeding pump, the rear end of the slurry mixing tank is connected to a slurry storage tank via a low-concentration mill feeding pump, and a slurry storage tank is arranged at the rear end of the low-concentration mill;

[0005] Furthermore, a slag knocking front trough is provided at the rear end of the de-knotting machine, a second-stage screen is provided at the rear end of the first-stage pressure screen, a slag knocking front trough is provided at the rear end of the second-stage screen, the slag knocking front trough is connected to the slag mill through a slag feeding pump, one end of the slag mill is connected to the slag knocking rear trough, one end of the slag knocking rear trough is connected to the second desander through the first slag pump, the second desander is connected to the spraying pot through the second slag pump, the other end of the slag knocking rear trough is connected to the spraying pot through the second slag pump, and the other end of the slag mill is connected to the spraying pot through the second slag pump.

[0006] Beneficial effects of the utility model:

[0007] The utility model adds two medium-consistency grinders at the outset of the cooking line, and can make a variety of raw materials and a variety of kappa ranges available; adds a low-consistency grinder in the pulping section, and can supply pulp with a variety of freeness options for the paper machine according to market demand; is equipped with a slag pulp mill when processing the screened pulp residue and wood knots, so as to process and recycle the pulp residue and wood knots, which not only realizes zero emission of harmful solid waste, but also increases the pulping yield, protects the environment and further increases the efficiency; the raw material type selectivity is strong, can adapt to the cooking of a variety of raw materials, can cook a wide kappa value range, saves energy consumption, and produces less or no solid waste such as pulp residue and wood knots, thereby reducing pollution to the environment and being more environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a schematic diagram of the main pulping process of a new chemical pulping system of the utility model. Figure 1 ;

[0009] Figure 2 This is a schematic diagram of the main pulping process of a new chemical pulping system of the utility model. Figure 2 ;

[0010] Figure 3 This is a schematic diagram of the process flow of treating wood knots and pulp residues in a novel chemical pulping system of the utility model;

[0011] As shown in the figure: 1 prepreg tower, 2 wood chip pump, 3 cooking tower, 4 medium concentration mill, 5 spray pot, 6 desander feeding pump, 7 first desander, 8 deknot machine, 9 first stage pressure screen, 10 vacuum pulp washer, 11 double roller feeding riser, 12 double roller pulp washer feeding pump, 13 double roller pulp washer, 14 double roller conveying screw, 15 medium concentration pulp tower feeding riser, 16 medium concentration pulp tower feeding pump, 17 first medium concentration pulp tower, 18 second medium concentration pulp tower, 19 first pulp delivery pump, 20 second pulp delivery pump, 21 pulp mixing tank, 22 low concentration mill feeding pump, 23 low concentration mill, 24 pulp storage tank, 25 second stage screen, 26 pre-knock pulp slag trough, 27 pulp slag feeding pump, 28 slag pulp mill, 29 first pulp slag pump, 30 second desander, 31 pulp slag knocking trough, 32 second pulp slag pump. DETAILED DESCRIPTION

[0012] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0013] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0014] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances. In addition, the technical features involved in the different embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other.

[0015] Example 1

[0016] The utility model provides a novel chemical pulping system, which is characterized by comprising a prepreg tower 1, a wood chip pump 2 is arranged at the rear end of the prepreg tower 1, a cooking tower 3 is arranged at the rear end of the prepreg tower 1, a medium-concentration mill 4 is arranged at the rear end of the cooking tower 3, a spray pot 5 is arranged at the rear end of the cooking tower 3, a desander feeding pump 6 is arranged at the rear end of the spray pot 5, a first desander 7 is arranged at the rear end of the desander feeding pump 6, a de-knot machine 8 is arranged at the rear end of the first desander 7, and a pressure screen 9 is arranged at the rear end of the first desander 7. A vacuum pulp washer 10 is arranged at the rear end of the first stage pressure screen 9, a double-roller feeding riser 11 is arranged at the rear end of the vacuum pulp washer 10, a double-roller pulp washer feeding pump 12 is arranged at the rear end of the double-roller pulp washer feeding pump 12, a double-roller pulp washer 13 is arranged at the rear end of the double-roller pulp washer 13, a double-roller conveying screw 14 is arranged at the rear end of the double-roller conveying screw 14, a medium-consistency pulp tower feeding riser 15 is arranged at the rear end of the medium-consistency pulp tower feeding riser 15, and a medium-consistency pulp tower feeding pump 16 is arranged at the rear end of the medium-consistency pulp tower feeding riser 15;

[0017] Further, a first medium-concentration slurry tower 17 is arranged at the rear end of the medium-concentration slurry tower feeding pump 16, and a second medium-concentration slurry tower 18 is arranged at the rear end of the medium-concentration slurry tower feeding pump 16. The first medium-concentration slurry tower 17 is connected to a slurry mixing tank 21 through a first slurry delivery pump 19, and the second medium-concentration slurry tower 18 is connected to a slurry mixing tank 21 through a second slurry delivery pump 20. The rear end of the slurry mixing tank 21 is connected to a low-concentration mill 23 through a low-concentration mill feeding pump 22. The rear end of the slurry mixing tank 21 is connected to a slurry storage tank 24 through a low-concentration mill feeding pump 22, and a slurry storage tank 24 is arranged at the rear end of the low-concentration mill 23.

[0018] Furthermore, a slurry knocking front trough 26 is provided at the rear end of the de-knotting machine 8, a second-stage screen 25 is provided at the rear end of the first-stage pressure screen 9, and a slurry knocking front trough 26 is provided at the rear end of the second-stage screen 25. The slurry knocking front trough 26 is connected to the slurry mill 28 through a slurry feeding pump 27, one end of the slurry mill 28 is connected to the slurry knocking rear trough 26, one end of the slurry knocking rear trough 26 is connected to the second desander 30 through the first slurry pump 29, the second desander 30 is connected to the spraying pot 5 through the second slurry pump 32, the other end of the slurry knocking rear trough 26 is connected to the spraying pot 5 through the second slurry pump 32, and the other end of the slurry mill 28 is connected to the spraying pot 5 through the second slurry pump 32.

[0019] Example 2

[0020] The wood chips are softened in the prepreg tower 1, and are transported to the cooking tower 3 through the wood chip pump 2 to increase the temperature of the cooking tower 3 to cook the wood chips. The outlet of the cooking tower 3 is equipped with two medium-concentration grinders 4. The smaller part of the cooked wood chips enters the spray pot 5, and the larger part passes through the two medium-concentration grinders 4 and then enters the spray pot 5. The raw materials enter the first desander 7 through the desander feeding pump 6. The raw materials are removed from stones, sand, iron blocks and other impurities in the first desander 7. The raw materials containing wood knots in the first desander 7 enter the desander 8 to remove the wood knots and then enter the first pressure screen 9. The raw materials without wood knots in the first desander 7 directly enter the first pressure screen 9. The first pressure screen 9 screens out the pulp residue. The pulp enters the vacuum pulp washer 10 for washing and then enters the double-roller feeding of the stable pulp. The pulp is fed into a double-roll pulp washer 13 through a double-roll pulp washer feeding pump 12 for washing, and then enters a medium-concentration pulp tower feeding riser 15 through a double-roll conveying screw 14. The pulp in the medium-concentration pulp tower feeding riser 15 is stored in a first medium-concentration pulp tower 17 and a second medium-concentration pulp tower 18 through a medium-concentration pulp tower feeding pump 16. The pulp in the first medium-concentration pulp tower 17 and the second medium-concentration pulp tower 18 enters a pulp mixing tank 21 through a first pulp delivery pump 19 and a second pulp delivery pump 20 for pulp mixing. The mixed pulp enters a pulp storage tank 24 through a low-concentration mill feeding pump 22 for storage. The low-concentration mill 23 is started and stopped according to the required freeness, and the mixed pulp in the pulp mixing tank 21 is ground. The ground pulp enters a pulp storage tank 24 for storage.

[0021] During the process of treating pulp residue and wood knots, the wood knots removed by the knot remover 8 enter the pulp residue knocking front trough 26, the pulp residue screened by the first stage pressure screen 9 enters the second stage screen 25, and the pulp residue screened by the second stage screen 25 also enters the pulp residue knocking front trough 26, and then the pulp residue mill feed pump 27 is transported to the pulp residue mill 28 for refining, and the ground pulp residue enters the pulp residue knocking rear trough 31, and the pulp residue after knocking is transported to the second desander 30 through the first pulp residue pump 29 to remove heavy impurities and discharge, and the good pulp is transported back to the spray pot 5 through the second pulp residue pump 32;

[0022] Two medium-consistency grinders 4 are provided at the outlet of the cooking tower 3, which enables the cooking system to cook a variety of raw materials with different kappa values. When the kappa value is between 100-130 for semi-chemical pulp and 80-100 for high kappa value, the medium-consistency grinder 4 can be operated. When the kappa value is between 25-35 for chemical pulp, the medium-consistency grinder 4 can be stopped to save energy. At the same time, because of the medium-consistency grinder 4, the raw materials of the cooking tower 3 are not limited to hardwood in principle. When cooking wood chips that are not very good, the screen plate pressure of the cooking tower 3 will increase. At this time, the kappa value can be selectively increased to reduce the pressure of the cooking tower.

[0023] The above shows and describes the basic principle and main features of the utility model and the advantages of the utility model. The various components mentioned in the utility model are common technologies in the existing field. The technicians in this industry should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only to illustrate the principles of the utility model. Without departing from the spirit and scope of the utility model, the utility model will have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection claimed by the utility model is defined by the attached claims and their equivalents.

Claims

1. A new chemical pulping system, characterized in that: It comprises a prepreg tower, a wood chip pump is arranged at the rear end of the prepreg tower, a cooking tower is arranged at the rear end of the prepreg tower, a medium-concentration mill is arranged at the rear end of the cooking tower, a spray pot is arranged at the rear end of the cooking tower, a desander feeding pump is arranged at the rear end of the spray pot, a first desander is arranged at the rear end of the desander feeding pump, a deknot machine is arranged at the rear end of the first desander, a pressure screen is arranged at the rear end of the first desander, a vacuum pulp washer is arranged at the rear end of the pressure screen, a double-roll feeding riser is arranged at the rear end of the vacuum pulp washer, a double-roll feeding riser is arranged at the rear end of the double-roll feeding riser, a double-roll pulp washer feeding pump is arranged at the rear end of the double-roll pulp washer, a double-roll pulp washer is arranged at the rear end of the double-roll pulp washer feeding pump, a double-roll conveying screw is arranged at the rear end of the double-roll conveying screw, a medium-concentration pulp tower feeding riser is arranged at the rear end of the medium-concentration pulp tower feeding riser, and a medium-concentration pulp tower feeding pump is arranged at the rear end of the medium-concentration pulp tower feeding riser.

2. A novel chemical pulping system according to claim 1, characterized in that: A first medium-concentration slurry tower is arranged at the rear end of the medium-concentration slurry tower feeding pump, and a second medium-concentration slurry tower is arranged at the rear end of the medium-concentration slurry tower feeding pump. The first medium-concentration slurry tower is connected to a slurry mixing tank through a first slurry delivery pump, and the second medium-concentration slurry tower is connected to a slurry mixing tank through a second slurry delivery pump. The rear end of the slurry mixing tank is connected to a low-concentration mill through a low-concentration mill feeding pump, and the rear end of the slurry mixing tank is connected to a slurry storage tank through a low-concentration mill feeding pump, and a slurry storage tank is arranged at the rear end of the low-concentration mill.

3. A novel chemical pulping system according to claim 2, characterized in that: A slag knocking front trough is arranged at the rear end of the de-knotting machine, a second-stage screen is arranged at the rear end of the first-stage pressure screen, a slag knocking front trough is arranged at the rear end of the second-stage screen, the slag knocking front trough is connected to the slag mill through a slag feeding pump, one end of the slag mill is connected to the slag knocking rear trough, one end of the slag knocking rear trough is connected to the second desander through the first slag pump, the second desander is connected to the spraying pot through the second slag pump, the other end of the slag knocking rear trough is connected to the spraying pot through the second slag pump, and the other end of the slag mill is connected to the spraying pot through the second slag pump.

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