Biomass pulp digester

Abstract

The multi-stage modular horizontal digester is primarily comprised of a single auger in a horizontal orientation. The single auger includes sections of lesser and greater inner diameter, thus creating sections of that allow for mixing and time to operate on the contents, and sections where the liquids are squeezed out. As compared to the known processing methodology, the multi-stage modular horizontal digester creates numerous benefits. For example, by maintaining elevation of the pulp, it can be directly expelled into the hydrapulper without the need for an additional pump. Processes can be changed quickly by altering the rotation speed, auger sections, or chemical inputs and outputs without the need to move heavy tanks or adjust pumps. In other words, there is no need for the standard cascade-style system where the pulp descends through a step, is raised to the next step, and so forth.

Claims

1. A multi-stage horizontal digester for use breaking down a pulp, the multi-stage horizontal digester comprising: two or more vessels; a multi-stage auger with an inner diameter and an outer diameter; the multi-stage auger within the two or more vessels; the multi-stage auger including two or more transportation sections and one or more compression section; one or more auger connections separating the two or more transportation sections and the one or more compression section; each auger connection of the one or more auger connections allowing the multi-stage auger to be separated and the sections rearranged into a different order; the two or more transportation sections each having a constant inner diameter and a constant outer diameter, thus allowing the pulp time to mix and break down without a need for use of a holding tank; the one or more compression section including an increasing inner diameter and a constant outer diameter, pushing the pulp outward against a screen to discharge liquid; the one or more compression section separating the two or more transportation sections, thus removing fluids from the pulp between the two or more transportation sections; the two or more vessels joined to each other by flanged connections; the flanged connections each including an auger support collar, and the flanged connections each matching with one or more auger connections; each auger support collar surrounding one or more auger connections; the auger support collar formed from an upper support half and a lower support half; whereby the multi-stage horizontal digester is separatably at the flanged connections of the two or more vessels, and the one or more auger connections of the multi-stage auger, allowing for reconfiguration and re-ordering of the sections.

2. The multi-stage horizontal digester of claim 1, wherein: the multi-stage auger of the one or more compression section is a de-watering auger; the de-watering auger includes an acceleration-section and an outward-compression section; the acceleration-section wherein a pitch of the multi-stage auger decreases, accelerating the pulp along a length of the multi-stage horizontal digester; the outward-compression section wherein an inner diameter of the multi-stage auger increases, pressing the pulp outward; whereby the de-watering auger causes the pulp to create a plug before outward compression to remove water, thus improving de-watering performance.

3. The multi-stage horizontal digester of claim 1, further comprising: a journal bearing; the journal bearing placed between the one or more auger connections and the auger support collar associated therewith; whereby the journal bearing reduces friction between the auger connection and the auger support collar.

4. The multi-stage horizontal digester of claim 1, further comprising: a set of filter bars; the set of filter bars surrounding the one or more compression section; the set of filter bars are arranged parallel to an axis of rotation of the multi-stage auger; the set of filter bars separated by a filter bar gap; whereby outward compression of the pulp against the set of filter bars permits discharge of liquid, while keeping solids within the multi-stage horizontal digester.

5. The multi-stage horizontal digester of claim 4, wherein: the set of filter bars are of a square cross-section; the set of filter bars taper along their length, increasing the filter bar gap in a downstream direction; whereby a larger downstream filter bar gap helps to prevent clogging.

6. The multi-stage horizontal digester of claim 1, wherein: the two or more transportation sections are each a digestion section where solvents break down solids in the pulp; and the one or more compression section is a solvent expeller where solvents are pressed out of the pulp.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description when considered in conjunction with the accompanying drawings in which:

(2) FIG. 1 illustrates a first isometric view of the multi-stage modular horizontal digester.

(3) FIG. 2 illustrates a second isometric view, including a cross-section of the auger, of the multi-stage modular horizontal digester.

(4) FIG. 3 illustrates a cross-sectional view of the multi-stage modular horizontal digester.

(5) FIG. 4 illustrates a view of the components of the multi-stage modular horizontal digester.

(6) FIG. 5 illustrates a short embodiment of the multi-stage modular horizontal digester.

(7) FIG. 6 illustrates a long embodiment of the multi-stage modular horizontal digester.

(8) FIG. 7 illustrates a connection detail of the multi-stage modular horizontal digester.

(9) FIG. 8 illustrates an isometric view of a second embodiment, including a cross-section of the auger, of the multi-stage modular horizontal hemp digester.

(10) FIG. 9 illustrates a detail view of a filtering/screening/expelling section of the multi-stage modular horizontal hemp digester.

(11) FIG. 10 illustrates a side view of the de-watering auger of the multi-stage modular horizontal hemp digester.

(12) FIG. 11 illustrates an isometric view of a helix of an auger of the multi-stage modular horizontal hemp digester.

(13) FIG. 12 illustrates a partially-exploded view of an auger support collar with journal bearing of the multi-stage modular horizontal hemp digester.

(14) FIG. 13 illustrates an auger with perforations, or holes.

DETAILED DESCRIPTION

(15) Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Throughout the following detailed description, the same reference numerals refer to the same elements in all figures.

(16) Referring to FIG. 1, a first isometric view of the multi-stage modular horizontal digester is shown.

(17) The multi-stage modular horizontal digester 1 includes a pulp input location 10, after which pulp 100 (see FIG. 3) is carried to a series of expelling segments/sections 24 and holding segments/sections 22 before reaching the discharge 26 into the hydrapulper 64.

(18) Also shown are the solvent holding tank 60 and wash solution holding tank 62.

(19) Referring to FIG. 2, a second isometric view, including a cross-section of the auger, of the multi-stage modular horizontal digester is shown.

(20) The multi-stage modular horizontal digester 1 includes a pulp input location 10, where the pulp 100 (see FIG. 3) drops into the auger 20, specifically transportation section 12. Rotation of the auger 20 by driver 16 carries the pulp 100 to the compression section 14, eventually to the discharge 26. Note that the compression sections 14 generally include shrouds to prevent spraying of liquids, but the shrouds are omitted for clarity.

(21) The auger 20 has two primary measurements: an auger root diameter 28 and an auger major diameter 29. The auger major diameter 29 remains consistent. The auger root diameter 28, or minor diameter, is consistent in transportation sections 12, and increases in compression sections 14. The result is compression of the pulp 100 and expulsion of liquids.

(22) Referring to FIG. 3, a cross-sectional view of the multi-stage modular horizontal digester is shown.

(23) The multi-stage modular horizontal digester 1 is shown in cross-section. The vessel 17, or body inside of which the auger 20 lies, includes a vessel inner diameter 18, which remains consistent.

(24) The pulp 100 first passes through the process fluid expeller 30, squeezing out expelled extract 170.

(25) The pulp 100 passes through the digestion section 32, moving in pulp flow direction 66, moving against the solvent flow direction 43. Thus, the solvent is introduced at solvent input 42, moving in solvent flow direction 43, and exiting at the solvent discharge 44.

(26) Pulp continues to the solvent expeller 34, where any entrained solvent leaves as expelled solvent 172.

(27) The pulp 100 continues, passing through the wash segment 36, moving in pulp flow direction 66, moving against the wash solution flow direction 49. Thus, wash solution is introduced at the wash solution input 48, moving in the wash solution flow direction 49, and exiting at the wash solution discharge 50.

(28) Entrained wash solution is discharged as expelled wash 174.

(29) The pulp 100 then exits at the discharge 26.

(30) Referring to FIG. 4, a view of the components of the multi-stage modular horizontal digester is shown.

(31) The multi-stage modular horizontal digester 1 is shown separated into its components: driver 16; input section 11; compression section 14; transportation section 12; and discharge 26. The elements are configurable to allow a user to adapt the multi-stage modular horizontal digester 1 to the required process.

(32) Referring to FIG. 5, a short embodiment of the multi-stage modular horizontal digester is shown.

(33) With only a single compression section 14 and transportation section 12, the process is simple, resulting in a short multi-stage modular horizontal digester 1.

(34) Referring to FIG. 6, a long embodiment of the multi-stage modular horizontal digester is shown.

(35) The compression sections 14 and transportation sections 12 are now repeated, allowing for a more complex process out of the same components of the multi-stage modular horizontal digester 1.

(36) Referring to FIG. 7, a connection detail of the multi-stage modular horizontal digester is shown.

(37) Bolts 70 are shown holding the flange 77 of a transportation section 12 and a compression section 14.

(38) The auger 20 is connected at the auger connection 71, which can be spade connection 72, socket connection 74, or spline connection 76.

(39) Referring to FIG. 8, an isometric view of a second embodiment, including a cross-section of the auger, of the multi-stage modular horizontal hemp digester is shown.

(40) The second embodiment of the multi-stage modular horizontal hemp digester 1 is shown with a pulp input location 10 adjacent to the driver 16. The pulp flows through a first expelling segment 24 with internal compression section 14. The first expelling segment 24 squeezes out the expelled extract 170.

(41) The pulp continues into the holding segment 22 with internal transportation section 12, the pulp moving in pulp flow direction 66. The solvent counter-flows with respect to the pulp, the solvent entering at solvent input 42, moving in solvent flow direction 43, and exiting at solvent discharge 44.

(42) The pulp continues into plug-forming segment 23 followed immediately by an expelling segment 24 that squeezes out expelled solvent 172.

(43) As detailed further below, the compression section with plug 15 lies within the plug-forming segment 23 with expelling segment 24, the creation of a plug aiding in removal of fluid from the pulp by decreasing the cross-sectional area of the pulp before creating outward compression.

(44) The formed plug moves in the plug movement direction 68.

(45) In this embodiment, the pulp 100 again flows through another series of processing and compression. This is shown as holding segment 22 with internal transportation section 12, then a plug-forming segment 23 followed immediately by an expelling segment 24. Finally the pulp 100 reaches the discharge 26.

(46) The wash solution also flows against the pulp flow, with wash solution entering at wash solution input 48, moving in the wash solution flow direction 49, and exiting at the wash solution discharge 50.

(47) The final expelling segment 24 discharges any entrained wash as expelled wash 174.

(48) The segments are joined at flanges 25, the flanges separated by an auger support collar 130. The auger support collar 130 allows rotation of the auger 20, while keeping the auger 20 centered within each segment.

(49) Referring to FIG. 9, a detail view of a filtering/screening/expelling section of the multi-stage modular horizontal hemp digester is shown.

(50) Between the flanges 25 are two sections: a solid section, or plug-forming segment 23, where internally the auger 20 compresses the pulp 100 into a plug, followed by an expelling segment 24 formed by a set of filter bars 160.

(51) The filter bars are preferably square or rectangular in shape, creating a natural widening as the filtered material passes outward—first through a narrow gap 162, then a wide gap 164. This increase in width helps to prevent clogging by making it easier any expelled material to finish passing through the filter.

(52) Additionally, the bars are optionally tapered in direction 166, creating a widening narrow gap 162, creating a multi-stage filter with smaller particles first able to exit, followed by larger particles.

(53) Referring to FIG. 10, a side view of the de-watering auger of the multi-stage modular horizontal hemp digester is shown.

(54) As a specific embodiment of the combination of an auger coil 120 and auger shaft 122, the de-watering auger 150 includes an acceleration-section 152 that forms a plug, and an outward-compression section 154 that presses the resulting plug against the wall of the vessel.

(55) To aid in generation of the plug, the acceleration-section 152 coincides with a solid plug-forming segment 23, and to aid in expulsion of water, the outward-compression section 154 coincides with an expelling segment 24 that acts as a filter.

(56) Referring to FIG. 11, an isometric view of a helix of an auger of the multi-stage modular horizontal hemp digester is shown.

(57) As an example of construction methodology, the auger coil 120 is shown coiled before being affixed to an auger shaft 122 (see FIG. 10).

(58) Referring to FIG. 12, a partially-exploded view of an auger support collar with journal bearing of the multi-stage modular horizontal hemp digester is shown.

(59) The auger support collar 130 is formed from an upper support half 132 and a lower support half 134. Each half 132/134 includes one or more pulp openings 136 to permit flow through the auger support collar 130.

(60) The auger support collar 130 includes collar bolt holes 140 through which bolts (not shown) can be passed to clamp the upper support half 132 to the lower support half 134.

(61) The flange bolt holes 142 allow bolts (not shown) to pass through the auger support collar 130, interacting with the flanges 25 (see FIG. 8).

(62) At the location where the auger shaft 122 contacts the auger support collar 130, a journal bearing 110 is placed to reduce friction. The journal bearing is formed from an upper sleeve 112 and a lower sleeve 114 to simplify maintenance.

(63) FIG. 13 illustrates an auger with perforations, or holes.

(64) The auger coil 120 is wrapped around an auger shaft 122, the auger coil 120 including a multiplicity of auger coil perforations 124.

(65) Equivalent elements can be substituted for the ones set forth above such that they perform in substantially the same manner in substantially the same way for achieving substantially the same result.

(66) It is believed that the system and method as described and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction, and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely exemplary and explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes.