Adjustment of high pressure feeder based on fluid leakage

Abstract

A method, system, and apparatus, including a computer program encoded on a computer storage medium, for adjusting a high-pressure feeder of a feeding system used in pulp production based on fluid leakage from a low-pressure outlet of the high-pressure feeder. The method includes obtaining a plurality of flow rates, including (1) a make-up liquor flow rate value, (2) a black liquor flow rate value, (3) a white liquor flow rate value, (4) a chip chute circulation flow rate value, and (5) a high-pressure feeder purge flow rate value. The method can include determining a chip flow rate value that specifies the flow of chips fed to the high-pressure feeder. Based on the flow rate values, the method can determine a fluid leakage value that specifies the amount of fluid leakage through a gap between a pocket rotor and a housing of the high-pressure feeder. The method can adjust the annular gap based on the fluid leakage value satisfying a leakage threshold.

Description

[Technical Field]

[0001] Priority claims This application claims the benefit of U.S. Provisional Patent Application No. 62 / 984,568, filed March 3, 2020, the entire contents of which are incorporated herein by reference. [Background technology]

[0002] SUMMARY OF THE INVENTION The present disclosure relates generally to adjusting a high pressure feeder of a feeding system used in pulp production based on fluid leakage from the high pressure side to the low pressure side of the high pressure feeder.

[0003] In feed systems used in pulp production, wood chips (or other cellulosic material) are typically fed to a processing vessel, such as a digester, which uses the wood chips in the production of cellulose pulp. A high-pressure feeder (HPF) is a component of the feed system that transfers wood chips and circulating liquor (described in more detail herein) from a low-pressure section of the system to a high-pressure section of the system. Typically, the HPF pressurizes the low-pressure feed of wood chips and circulating liquor (e.g., to approximately 20-25 psig) and delivers the resulting chip slurry to the digester at a significantly higher pressure (e.g., approximately 200-250 psig). The HPF is a critical component of the feed system because, without it, the high-pressure section of the system would not receive a high-pressure feed of chips and liquor, resulting in a complete cessation of pulp production.

[0004] Like other mechanical components, HPFs typically deteriorate over time. As an HPF deteriorates or begins to deteriorate, fluid leakage from the HPF's low-pressure outlet may increase or decrease. Increased fluid leakage can reduce the pressure of the chip slurry being fed to the digester. Meanwhile, reduced fluid leakage can limit or eliminate lubrication of certain HPF components (such as the pocket rotor and chamber), potentially resulting in metal-to-metal contact. This can accelerate HPF deterioration. Without proper and / or regular maintenance and adjustment, an HPF will eventually fail, potentially halting pulp production until the HPF is repaired and put back into service. Summary of the Invention [Means for solving the problem]

[0005] In general, one innovative aspect of the subject matter described herein can be embodied in a method that can include operations for controlling fluid leakage in a high-pressure feeder of a feeding system, the method comprising the steps of obtaining a plurality of flow values ​​from a plurality of flow meters, the flow values ​​including: (1) a make-up liquor flow rate value identifying a flow of make-up liquor to a digester; (2) a black liquor flow rate value identifying a flow of black liquor to the feeding system; (3) a white liquor flow rate value identifying a flow of white liquor to the feeding system; (4) a chip chute circulating flow rate value identifying a flow of low-pressure circulating liquor from a low-pressure outlet of the high-pressure feeder; and (5) a high-pressure feeder purge flow rate value identifying a flow of white liquor to a high-pressure inlet of the high-pressure feeder; The method includes obtaining a chip speed using a chip speed encoder to determine a chip flow rate value that determines a flow of chips being fed into the high-pressure feeder, using the chip speed to determine a chip flow rate value that determines a flow of chips being fed into the high-pressure feeder, using the plurality of flow rates and the chip flow rate value to determine a fluid leakage value that determines an amount of fluid leakage through a gap between a pocket rotor and a chamber of the high-pressure feeder, determining that the fluid leakage meets a leakage threshold, and adjusting the annular gap between the pocket rotor and the housing in response to determining that the fluid leakage meets the leakage threshold. Other embodiments of this aspect include corresponding systems, devices, and computer programs configured to perform the actions of the method encoded in computer storage.

[0006] Each of these and other embodiments can optionally include one or more of the following features.

[0007] In some implementations, determining the fluid leakage value using the plurality of flow rates and chip flow rates may include calculating a sum of the black liquor flow rate value, the white liquor flow rate value, the chip chute circulation flow rate value, and the high-pressure feeder purge flow rate value, and reducing the make-up liquor flow rate value by the calculated sum to obtain the fluid leakage value.

[0008] In some implementations, adjusting the annular gap between the pocket rotor and the housing includes moving the pocket rotor into the housing.

[0009] In some implementations, moving the pocket rotor into the housing can include moving the pocket rotor axially relative to the housing, and the method can further include the pocket rotor being coaxial with the housing.

[0010] In some implementations, determining a chip flow rate value specifying the flow of chips provided to the high-pressure feeder can include scaling the chip meter rate by (1) a wood chip volumetric capacity specifying the amount of wood chips provided to the high-pressure feeder at the chip rate, and (2) a discharge value specifying the rate at which air is expelled from the wood chips fed to the high-pressure feeder.

[0011] Certain embodiments of the subject matter described herein can be implemented to realize one or more of the following advantages: The innovations described herein can determine appropriate adjustments to the high-pressure feeders of the feeding system based on fluid leakage from the low-pressure outlet of the HPF. By applying appropriate adjustments to the HPF, the approaches described herein can extend the operating life and / or stability of the HPF, thereby avoiding unexpected or premature defects and / or failures of the HPF. Extending the operational period between maintenance and repairs of the HPF can reduce potential interruptions to pulp production and allow the digester to continue producing pulp.

[0012] Additionally, the techniques described herein provide better control of fluid leakage through the HPF. This not only improves the operational stability of the HPF, but also reduces the load on downstream equipment and improves the performance of other control and processing equipment in the system. Thus, by providing better control of fluid leakage, the techniques described herein can extend the life of equipment, valves, etc., and / or improve the overall production capacity of the system.

[0013] The techniques described herein can also accurately determine the amount of fluid leakage from the low-pressure outlet of the HPF, which can be used to determine the specific amount of adjustment to apply to the HPF (as described further herein). Conventional techniques for determining fluid leakage can be inaccurate. For example, one conventional technique determines the rate of fluid leakage based on changes in the ratio of make-up flow to chip flow. However, because this conventional technique does not determine the exact amount of fluid leakage, any resulting adjustments to the HPF based on an inaccurate measurement of this increase or decrease in fluid leakage are similarly inaccurate. Other conventional techniques have attempted to estimate fluid leakage by approximating the difference between the flow through the high-pressure outlet of the HPF and the total flow to the HPF. Due to a lack of actual measurement data, conventional techniques are unable to accurately and precisely determine fluid leakage. As a result, these and other conventional techniques lack the precision and accuracy of the techniques described herein and are unable to extend the operating life of the HPF to the same extent (e.g., with the same precision) as the techniques described herein. Thus, the techniques described herein provide advantages over conventional techniques.

[0014] The details of one or more embodiments of the subject matter described herein are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the subject matter will become apparent from the description, drawings, and claims. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic diagram of a portion of a conventional feed system used in paper pulp processing. [Figure 2] FIG. 2 is a perspective view of the high-pressure feeder of FIG. 1. [Figure 3] FIG. 2 is an exploded view of the high-pressure feeder of FIG. 1. [Figure 4A] 3 shows a block diagram of the communication between the controller of FIG. 2 and the components of the high pressure feeder of FIG. 1; [Figure 4B] 3 shows a block diagram of another controller assembly that can be used in conjunction with the controller of FIG. 2 in adjusting the HPF. [Figure 5] 5 is a flow diagram of an exemplary process for adjusting the HPF of FIGS. 1-4 based on fluid leakage through a low-pressure outlet of the HPF. [Figure 6] 1 is a block diagram of a computing system that may be used in connection with the methods described herein.Like reference numbers and designations in the various drawings indicate like elements. DETAILED DESCRIPTION OF THE INVENTION

[0016] This specification relates to a technique for adjusting a high-pressure feeder of a feeding system used in pulp production based on fluid leakage from the high-pressure side to the low-pressure side of the high-pressure feeder, for example, through the annular region between the rotor and the housing.

[0017] As described further throughout this specification, the controller determines fluid leakage through the low-pressure outlet of the high-pressure feeder. The controller determines fluid leakage based on fluid flow throughout the feed system. In some implementations, the controller (1) uses a chip speed encoder to obtain chip flow to the high-pressure feeder, (2) uses multiple flow meters to obtain make-up liquid flow to the digester, black liquor flow to the feed system, white liquor flow to the feed system, chip chute circulation flow from the low-pressure outlet of the high-pressure feeder, and (5) high-pressure feeder purge flow to the high-pressure inlet of the high-pressure feeder. The controller determines fluid leakage based on these flow rate values. In some implementations, the controller can determine fluid leakage by calculating the difference between the make-up liquid flow and the sum of the white liquor flow rate, black liquor flow rate, chip chute circulation flow rate, and high-pressure feeder purge flow.

[0018] The controller uses the determined fluid leakage value when adjusting the high-pressure feeder. In some implementations, the controller determines whether the fluid leakage value meets (e.g., exceeds or is less than) a leakage threshold. If the controller determines that the fluid leakage value meets (e.g., exceeds) the leakage threshold, the controller adjusts (e.g., decreases) the annular gap (e.g., the width of the gap) between the pocket rotor and the chamber of the high-pressure feeder. On the other hand, if the controller determines that the fluid leakage value does not meet (e.g., is less than) the leakage threshold, the controller 240 adjusts (e.g., increases) the annular gap between the pocket rotor 204 and the chamber 206.

[0019] These and other features are explained in more detail in the description below.

[0020] FIG. 1 is a schematic diagram of a portion of a conventional feed system 100 used in pulp and paper processing.

[0021] As part of feed system 100, wood chips 104 from a chip bin or another chip feed system are fed to chip chute 106 by a rotary chip meter having a speed encoder 102. Simultaneously as chips 104 are fed to chip chute 106, circulating liquor (which may include, for example, white liquor and / or black liquor) is introduced into chip chute 106 at low pressure (e.g., about 18-20 PSIG) via conduit 108. The circulating liquor is fed to feed system 110 via conduit 162.

[0022] A flow meter 134 (e.g., a magnetic flow meter) located in / on / around the conduit 134 measures the fluid flow rate (e.g., in gallons per minute or another suitable unit) of the white liquor. Similarly, black liquor, which is also used during operation of the supply system, is introduced into the supply system 100, and a flow meter (e.g., a magnetic flow meter) located in / on / around the conduit through which the black liquor passes measures the fluid flow rate (e.g., in gallons per minute or another suitable unit) of the black liquor.

[0023] The combination of circulating liquor and wood chips 104 (also referred to as chip slurry) passes through chip chute 106 toward high-pressure feeder (HPF) 112. The chip slurry travels to HPF 112 at a pressure of approximately 18-25 PSIG. After passing through HPF 112, the chip slurry (or a portion thereof) travels at a relatively high pressure, for example, approximately 225 PSIG. The high-pressure slurry is suitable for introduction into a continuous digester, chip steaming vessel, or other high-pressure chip processing equipment.

[0024] The high-pressure slurry travels via high-pressure conduit 114 to the inlet of the digester's overhead separator (not shown in FIG. 1 ). In the digester, some or all of the excess circulating liquid in the slurry is separated from the chip slurry by a liquor separator and returned to pump 118 via conduit 150. Pump 118 pressurizes the circulating liquid in conduit 150 and supplies it at high pressure via conduit 120 to the high-pressure inlet 122 of the HPF 112. This resulting high-pressure circulating liquid stream (also referred to as the high-pressure feeder purge stream) enters the HPF 112 and pressurizes the chip slurry from the chip chute 106, causing the chip slurry to exit the HPF at high pressure and enter conduit 114. A flow meter (e.g., a magnetic flow meter) located at or near the HPF 112 or high-pressure inlet 122, referred to as the high-pressure purge flow meter, measures the fluid flow rate of the high-pressure feeder purge stream (e.g., in gallons per minute or another suitable unit).

[0025] HPF 112 also has a low-pressure outlet 116 through which liquid is discharged. The liquid flowing through low-pressure outlet 116 is the low-pressure circulation flow (also referred to as the chip chute circulation flow). A flow meter 130 (e.g., a magnetic flow meter), also referred to as a chip chute circulation flow meter 130, disposed in or around conduit 138 measures the fluid flow (e.g., in gallons per minute or another suitable unit) of the low-pressure circulation (i.e., the chip chute circulation flow).

[0026] This low-pressure circulating stream passes via conduit 138 and pump 142 to separator 140 (e.g., a sand separator), which separates undesirable materials and debris, such as sand and stones, from the liquid. The resulting liquid discharged from separator 140 (which generally contains circulating liquid and potentially small wood chips) contains little or no undesirable materials or debris and passes through liquid separator 144 (e.g., an in-line drainer). Liquid separator 144 separates the circulating liquid, including potentially small chips and at least some liquid, from the resulting liquid discharged from separator 140. The resulting circulating liquid is supplied to chip chute 106 via conduit 108. The remaining liquid separated by liquid separator 144 is sent via a conduit to level tank 152. Level tank 152 discharges some liquid, which is supplied via a conduit to makeup pump 154, which discharges makeup liquid. A flow meter 136 (e.g., a magnetic flow meter) on / in / around conduit 160, referred to as make-up flow meter 136, measures the fluid flow rate of the make-up liquid (e.g., in gallons per minute or another suitable unit). Make-up liquid is supplied to the digester via conduit 160.

[0027] FIG. 2 is a perspective view of the HPF 112 of FIG.

[0028] The HPF 112 includes a stationary housing 202 having a pocketed cylindrical rotor (also called a pocket rotor) 204 mounted for rotation within a tapered cylindrical chamber 206 of the housing 102. The housing includes four ports: a high-pressure inlet 122 (located at the rear of the housing and shown in FIG. 1), a high-pressure outlet 208, a low-pressure inlet 210, and a low-pressure outlet 116 (located at the bottom of the housing and shown in FIG. 1). The low-pressure inlet 210 is opposite the low-pressure outlet 116 on the housing, and the high-pressure inlet 122 is opposite the high-pressure outlet 208 on the housing.

[0029] The pocket rotor 204 is driven by a variable speed motor and gear reducer 212 coupled to a drive shaft 214. The pocket rotor 204 is driven to rotate within the housing chamber 202 such that the through pockets 216 of the rotor sequentially communicate with the four inlet / outlet ports of the housing.

[0030] The pocket rotor 204 includes two or more through pockets 216 (as further shown in FIG. 3) such that as the rotor rotates, different pockets communicate with different high- and low-pressure inlets / outlets. Each pocket in the rotor defines a passageway through the rotor with an opening on the opposite side of the passageway. The rotor can rotate at speeds of approximately 5 to 15 revolutions per minute (rpm), or preferably approximately 7 to 10 rpm, depending on the capacity of the HPF and the production rate of the pulping system used to feed it.

[0031] The low-pressure outlet port of the HPF 112 may be provided with a screen element (such as, for example, screen 302 shown in FIG. 3) that retains the chips in the slurry within the feeder and allows some of the liquid in the slurry to pass through the screen at the second end of the pocket and out the low-pressure outlet port.

[0032] Chips 104 flow into pockets 216 of pocket rotor 204 when the opening of the pocket aligns with the low-pressure inlet 210 and low-pressure outlet 116 of HPF 112, for example, when the pocket is vertical. The chips flow into the pocket from chip chute 106 and mix with the remaining chips held in the pocket by a screen element. The screen element prevents the chips from passing through the pocket and out the low-pressure outlet 116. When the pocket is rotated 90 degrees, for example, a quarter turn, the opening of the pocket aligns with the high-pressure inlet 122 and high-pressure outlet 208 of HPF 112, and the chips in the pocket move from the low-pressure flow to the high-pressure flow.

[0033] After a quarter rotation of the rotor, the first ends of the pockets that were in communication with the low-pressure inlet 210 are now positioned in communication with the high-pressure outlet 208. The high-pressure outlet is typically in communication with the inlet of a digester (e.g., a continuous or batch digester) via one or more conduits. Simultaneously, this quarter rotation of the rotor places the second ends of the through pockets that were just in communication with the low-pressure outlet in communication with the high-pressure inlet 122. The high-pressure inlet 122 typically receives a flow of high-pressure circulating fluid from a pump (e.g., a high-pressure hydraulic pump) 118. The pressure of this circulating fluid is typically in the range of about 5 to 15 bar gauge, typically about 7 to 10 bar gauge. This high-pressure circulating fluid displaces the chip slurry from the through pockets and discharges it through the high-pressure outlet of the HPF 112 (which leads to the digester via conduit 114).

[0034] As the pocket rotor continues to rotate, the second ends of the pockets that received the high-pressure fluid are placed in communication with the low-pressure inlet, which receives another supply of chip slurry from a conduit connected to the low-pressure inlet. Similarly, the first ends of the pockets are rotated to communicate with the low-pressure outlet of the housing containing the screen element.

[0035] The above-described operation of the HPF 112 is repeated so that each through pocket receives and discharges two supplies of chip slurry during one complete rotation of the rotor. The rotor may include two (or another suitable number, such as four) through pockets that alternately receive chip slurry from a low-pressure inlet and discharge chip slurry from a high-pressure outlet. The ends of these pockets serve as both the inlet and outlet for the chip slurry, depending on the orientation of the rotor.

[0036] FIG. 3 is an exploded view of the HPF 112 of FIG. 1, showing the pocket rotor, the cylindrical chamber of the feeder housing, and the screen plate of the HPF.

[0037] The pocket rotor 204 of the HPF 112 has a cylindrical shape with a slight taper extending from one end 304 of the rotor to the opposite end 306 of the rotor. The first end 44 of the rotor may be of a smaller diameter than the opposite end 306 of the rotor. The pocket rotor 204 fits into a tapered cylindrical chamber 206 (also shown in FIG. 2) that is secured to the housing.

[0038] The chamber 206 has a taper similar to that of the pocket rotor 204. A first end 308 of the chamber has a smaller diameter than an opposite end 310 of the chamber. The chamber 206 includes openings 220 (shown in FIG. 2) that align with the inlet and outlet of the housing of the HPF 112. Chip slurry flows through the openings of the chamber 206, enters the pockets 216 of the pocket rotor 204, and exits the pockets through the openings of the chamber to the high-pressure outlet of the HPF. Similarly, high-pressure liquid flows through the openings of the chamber, enters the pockets of the rotor, exits through the openings of the chamber, and is discharged through the low-pressure outlet of the HPF 112.

[0039] When the rotor is inserted into the chamber, a small, tapered annular gap 222 (also called clearance) is formed between the rotor 204 and the chamber 206. The gap 222 allows the rotor to rotate within the chamber.

[0040] The gap / clearance allows a small amount of liquid to act as a lubricant between the pocket rotor and the chamber. This liquid flows through gap 222, such as from the outlet of pocket rotor 204. The liquid (also called chip chute circulating liquid) is discharged below the chamber through screen 302 adjacent to the low-pressure outlet of HPF 112. The liquid from the low-pressure outlet can be recycled, for example, in feed system 100.

[0041] If the gap is too wide, there may be a pressure loss in the high-pressure fluid flow through the HPF 112, excess liquid and fines may flow through the gap and accumulate within the housing, for example, on the housing end bells, or excess liquid may leak out the low-pressure outlet of the HPF, resulting in a loss of hydraulic pressure. Conversely, if the gap is too narrow, there may be metal-to-metal contact between the rotor and chamber, which may trap debris in the gap and etch grooves in the rotor and chamber.

[0042] The width of the gap is determined by the axial position of the pocket rotor 204 relative to the chamber 206. Due to the complementary shapes of the pocket rotor 204 and the chamber 206, the gap can be narrowed by moving the pocket rotor 204 axially toward the small diameter end of the chamber 206. Similarly, the gap 222 can be widened by moving the rotor pocket axially toward the large diameter end of the chamber. During axial movement, the pocket rotor 204 remains within the chamber 206.

[0043] The width of the gap 222 can be changed / adjusted by moving the rotor axially relative to the housing. In some implementations, this gap adjustment is achieved using a motor-driven shaft 214 (shown in FIG. 2 and described further with reference to FIGS. 4A and 4B) connected to the end of the pocket rotor 204. The shaft 214 is axially aligned with the pocket rotor 204. A controller assembly 240 adjusts the axial position of the shaft, and therefore the axial position of the pocket rotor within the chamber of the housing (described further with reference to FIGS. 4A and 4B).

[0044] Additionally, liquid may collect in end bell chambers 230 of the housing adjacent both ends of pocket rotor 204 and chamber 206. The liquid in bell chambers 230 is preferably maintained under pressure to prevent further flow into the bell chambers, which may contain fines. Additional white liquor conduits 232 are connected to the inlet ports to each bell chamber 230 at both ends of the housing for the HPF. White liquor is supplied under pressure from conduit 232 (via conduit 122) to pressurize the liquid in the bell chambers and prevent the flow of liquid and fines from pocket rotor 204 into bell chambers 230.

[0045] If the gap 222 is too large, excess liquid and small particles (e.g., fiber fines and other small debris, especially metal, rock, and sand) can enter the gap through the openings in the pocket rotor, forming grooves on the outer surface of the pocket rotor 204 and the inner surface of the chamber 206. The fines and debris can flow through the gap and collect in the internal bell chamber 230 adjacent the axial end of the pocket rotor 204. Excessive accumulation of fines and debris in the bell chamber can cause the fines to resist rotor rotation, leading to wear on rotor components and increased power consumption by the high-pressure feeder 112.

[0046] FIG. 4A shows a block diagram of the communication between the controller 240 of FIG. 2 and the components of the HPF 112 that adjust the axial position of the pocket rotor.

[0047] Shaft 242 (as shown in FIG. 2) is housed within housing 320, which is contained within end bell housing 230 of HPF 112. Controller assembly 402 includes an actuator for axially moving shaft 242 and pocket rotor 204. The actuator includes a gear motor 404 and gearbox 406 that control the axial position of shaft 242, and therefore the axial position of the pocket rotor.

[0048] The gearbox engages the helical threads of the shaft 242 to rotate the shaft. Rotation of the shaft 242 by the gearbox causes axial movement of the shaft and pocket rotors. The gear motor 404 receives commands from the computer controller 240 to rotate the gearbox 406 a predetermined angular amount. By commanding the gear motor 404 and gearbox 406, the computer controller 240 adjusts the axial position of the shaft and pocket rotors. The gear motor 404 tracks the rotation of the shaft by the gearbox 406 and provides a rotational signal that allows the computer controller 240 to determine the current axial position of the shaft 242. Additionally, the axial position of the shaft can be monitored or measured by a position sensor, such as a laser position sensor 410.

[0049] In some implementations, the controller assembly 402 forms a cantilever beam attached at one end to the housing of the HPF 112 and is attached to the HPF 112 by a pair of brackets 412 that support tracks 414 for the rollers 416 of the controller assembly 402. The brackets 412 may be hollow, rectangular beams that extend horizontally. The controller assembly 402 may fit between the brackets. The controller assembly's roller wheels 416 ride on the tracks 414, allowing the controller assembly 402 to move laterally along the tracks as the shaft 242 moves laterally relative to the HPF 112. A pair of roller wheels 416 on either side of the controller assembly 402 are attached to a frame 418 that is fixed to the controller assembly 402. The roller wheels may include annular grooves that ride on ridges in the tracks 414.

[0050] A lower frame 420 is also secured to each side of the controller assembly 402. The lower frame 420 includes bolts 422, pins, or other positioning devices that prevent the roller wheels 416 from jumping upward and / or unintentionally falling off the track. The bolts 422 can be retracted to attach or detach the controller assembly 402 to or from the HPF 112.

[0051] A generally horizontal frame 424 supports the gear motor 404, gearbox 406, and other components of the controller assembly. The horizontal frame is positioned between brackets 412. Protective guards 470 may cover the rollers 416 and tracks 414.

[0052] The computer controller 240 receives input signals indicative of the operating status of the HPF and chip delivery system. The input signals may be generated by sensors, flow meters, or other devices distributed throughout the delivery system 100. For example, the input signals may be provided by vibration or acoustic sensors 250 (as shown in FIG. 2). The HPF housing may include three or four (or another suitable number of such sensors) in the HPF housing. Monitoring the vibration or sound of the HPF can indicate whether metal-to-metal contact is occurring between the pocket rotor and the chamber.

[0053] As another example, the input signal may be generated by a chip meter having a speed encoder 102 (as shown in FIG. 1 ) that measures the rate (e.g., revolutions per minute) at which wood chips 104 are fed into the chip chute 106. As another example, the input signal may be generated by a power meter in the HPF's motor drive. Such a meter may measure the electrical load on the HPF 112. As another example, the input signal may be generated by a flow meter (e.g., a magnetic flow meter), such as the flow meter (e.g., the flow meter shown and described with reference to FIG. 1 ). As another example, the input signal may be generated by a pressure sensor 426 internal to the HPF 112, such as the bell chamber 230. As another example, the input signal may be generated by a sensor 428 that measures the rotation and position of the drive shaft 242 and a sensor 252 (shown in FIG. 2 ) that measures the fluid pressure in the gap 222. Those skilled in the art will appreciate that one or more other sensors may be utilized to measure the operating parameters / conditions of the HPF and / or the chip feed system.

[0054] The computer controller 240 monitors one or more of these signals to monitor the operating status of the HPF 112 and / or the delivery system 100. Based on these signals, the computer controller 240 can determine the appropriate size of the gap 222 between the pocket rotor 204 and the chamber 206 in the HPF 112 (as further described below with reference to FIG. 5). The controller 240 uses the appropriate gap clearance to determine the desired axial position of the shaft 242. As described below, the controller 240 can utilize one or more of the above-mentioned signals in determining the amount of fluid leakage through the gap 222 (as further described with reference to FIG. 5). Based on the amount of fluid leakage through the gap 222, the controller 240 can adjust (or cause an adjustment to) the gap 222 to increase or decrease the leakage (as further described with reference to FIG. 5).

[0055] The computer controller 240 may include a display and user input device 430 that presents information to a human operator regarding the current operating state of the HPF and displays prompts for proposed changes in the axial position of the pocket rotor 204. For example, the displayed prompt may indicate that the pocket rotor 204 should be advanced inward or outward by a proposed distance, e.g., 2 mm, or by a predetermined step, e.g., one or two.

[0056] The computer controller 240 can have two modes: manual and automatic. In manual mode, the controller does not automatically adjust the axial position of the pocket rotor. Rather, in this mode, the controller 240 may only display suggested actions for the benefit of a human operator reading the display by generating prompts presented on the display. Manual mode allows the operator to input commands into the user interface device 430 (or another device, such as a remote computer 432) to cause the drive gear to advance or retract the shaft 242 and pocket rotor 204 an operator-specified distance. The commands may include, for example, a command to advance the pocket rotor (e.g., by one millimeter) or a command to position the pocket rotor 204 at a specific axial position. The positioner motor receives commands from the computer controller 240 indicating the rotation to be applied, causing the gear to rotate and move the shaft 242 and pocket rotor axially. For example, the computer controller 242 can command a positioned motor to rotate a gear in the gearbox 406 a fixed amount of rotation clockwise and counterclockwise over a predetermined period of time to move the pocket rotor axially in and out to flush fines from the bell chamber. In some implementations, if the controller 240 detects that an operator has moved the pocket rotor axially too far, causing the power load to exceed a predetermined maximum load, the controller 240 can automatically override the human operator and retract the pocket rotor to increase the gap 222. In such implementations, the controller can also generate an alert (and / or trigger an alarm) to inform the operator that the maximum motor power load has been exceeded.

[0057] In automatic mode, computer controller 240 includes the functionality of the manual mode and additional functionality that allows a human operator to authorize controller 240 to automatically perform certain actions, such as (1) actuating the drive gear to automatically advance or retract shaft 242 and pocket rotor 204, and (2) performing a "flush operation," which moves the axial position of the pocket rotor slightly in and out in a circular operation to flush fines from end bell 230 of the HPF housing. Fines are small fibrous particles of wood chips. Additionally, in automatic mode, if the controller detects that an excessive amount of fines may be present in the end bell, display 430 prompts the operator to authorize the flush operation.

[0058] The computer controller 240 may have a remote mode that automatically adjusts the axial position of the shaft and pocket rotor based on analysis performed by the controller 240 of signal inputs regarding the status of the HPF 112 and / or the feed system 100 in general. In the remote mode (but equally applicable to automatic and manual modes), the controller 240 may report the operating status of the HPF 112 and / or the feed system to a remote computer 432, typically via the Internet. In the remote mode, the axial position of the pocket rotor may be adjusted based on commands entered into the remote computer 432 by an operator.

[0059] At least in remote mode, the computer controller 240 automatically rotates the gears in the gearbox 406 to move the shaft and pocket rotor, thereby adjusting the clearance gap 222. The controller 240 can adjust the clearance based on sensor signals that provide data and algorithms for the operation of the HPF stored in the electronic memory of the controller 240. The algorithms convert input signals from the sensors and commands from the operator into command signals for the gear motor 404 and gearbox 406.

[0060] Figure 4B shows a block diagram of an alternative controller assembly 490 that can be used in conjunction with controller 240 of Figure 2 in regulating HPF 112. Controller assembly 490 can be substituted for controller assembly 420 described with reference to Figure 4A.

[0061] The controller assembly 490 may be mounted in a fixed position to the HPF 112 (via the HPF's bearing housing). Because the controller assembly 490 is fixed, it does not include any beams, rollers, brackets, wheels, tracks, or frames (as in the controller assembly 402). The controller assembly 490 includes a motor 482 and a fixed gearbox 486 (collectively referred to as the gear motor 490). The quill of the gear motor 490 is splined, as is the spindle 484, allowing the spindle 484 to slide axially through the gearbox 486 when powered. The spindle 484 is splined through the gearbox 486, but may have external threads through the bushing 480.

[0062] Gear motor 490 rotates spindle 484, causing the spindle assembly to move axially and spindle 484 to rotate bearing housing 488. As spindle 484 rotates bearing housing 488, the HPF rotor shaft assembly (as described above) rotates independently.

[0063] Compared to controller assembly 420, controller assembly 490 is safer because it does not have open wheel pinch points, and is more stable because the gearbox is fixedly mounted to the HPF housing. Additionally, because it uses many of the same parts as existing HPFs, the controller assembly is easier to retrofit (compared to controller assembly 420) to existing HPFs. This retrofitability allows for a higher factor of safety during transient conditions, such as when one side of HPF 112 is more pressurized than the other.

[0064] 5 is a flow diagram of an exemplary process 500 for adjusting the HPF 112 based on fluid leakage through the low-pressure outlet of the HPF 112. The operations of process 500 may be implemented, for example, by the system components shown in FIGS. 1-4 (including FIGS. 4A and 4B) and / or one or more data processing / computing devices (as described with reference to FIG. 6). For purposes of explanation, the operations of process 500 are described below as being performed by computer controller 240 in conjunction with controller assembly 402 and other components of the HPF 112. In some implementations, the operations of process 500 may also be implemented as instructions stored on a non-transitory computer-readable medium, where execution of the instructions by one or more data processing devices causes the one or more computing devices / data processing devices to perform the operations of process 500.

[0065] The controller 240 obtains (502) multiple flow rate values ​​from multiple flow meters. The controller 240 receives multiple flow rate values ​​(in response to queries to the multiple flow meters or unprompted by the flow meters). In some implementations, the controller 240 receives (1) a feed liquor flow rate value from the feed liquor flow meter 136 that identifies the flow of feed liquor to the digester, (2) a black liquor flow rate value from the black liquor flow meter that identifies the flow of black liquor to the feed system 100, (3) a white liquor flow rate value from the white liquor flow meter 134 that identifies the flow of white liquor to the feed system 100, (4) a chip chute circulation flow rate value from the chip chute circulation flow meter 130 that identifies the flow of low-pressure circulation liquor from the low-pressure outlet of the HPF 112, and (5) a high-pressure feeder purge flow rate value from the HPF purge flow meter 122 that identifies the flow of circulation liquor to the high-pressure inlet of the HPF 112. In some implementations, each of these flow rate values ​​may be in units of gallons per minute (or another suitable unit for measuring fluid flow). If the flow values ​​are not all measured using the same units of measurement, the controller 240 converts one or more of the respective flow values ​​upon receiving them so that all flow values ​​are expressed using the same units of measurement.

[0066] In some cases, failure of one or more flow meters and / or speed encoders (or other measuring instruments) may prevent the flow rate from being determined, resulting in an inaccurate or complete failure of the leakage flow rate determination. In such cases, other parameters / metrics may be used to estimate the respective flow rate values. For example, the flow rate values ​​may be estimated using one or more of the following example parameters / metrics: valve position, HPF inlet pressure, HPF outlet pressure, valve open position, and other valve characteristics.

[0067] The controller 240 obtains 504 a tip speed that identifies the rate at which wood chips are fed to the high-pressure feeder. In some implementations, in response to a query by the controller 240 to the tip speed encoder 102 (or without a query or other prompt), the controller 240 receives the tip speed from the tip speed encoder 102. The tip speed may be measured in revolutions per minute, although another suitable unit of speed measurement may be used to record the tip speed.

[0068] The controller 240 determines (506) a chip flow value that specifies the flow of chips delivered to the high-pressure feeder. In some implementations, the controller 240 determines the chip flow value using the chip velocity obtained in operation 504. In such embodiments, the controller 240 determines the chip flow value by scaling the chip meter speed by (1) the volumetric capacity of wood chips and (2) the discharge value. The volumetric capacity refers to the amount of wood chips delivered to the HPF 112 at a particular chip meter speed. In some implementations, the capacity value is in units of cubic feet per RPM (i.e., ft 3The capacity value is measured in gallons / rpm, although other suitable units of measurement, such as gallons / rpm, can be used. This capacity value is a constant value based on the design of the feed system 100. The discharge value refers to the rate at which air is displaced from the wood chips being fed to the HPF 112. In some implementations, the discharge value is a constant value (e.g., a value of 0.4) that can be provided by the operator of the feed system 100.

[0069] Tip speed is measured in RPM (revolutions per minute) and volumetric capacity is measured in ft 3 In embodiments measured in cubic feet per rpm, the controller 240 determines the tip flow rate value in gallons per minute by multiplying the tip speed by the volumetric capacity and discharge value, and then converts the resulting value to gallons per minute (e.g., by further multiplying the resulting value by a cubic feet to gallons conversion factor of 7.48).

[0070] The controller 240 determines (508) a fluid leakage value that identifies the amount of fluid leakage through the gap between the pocket rotor and the chamber of the HPF 112. The controller 240 determines the fluid leakage value based on the flow rate value (obtained in operation 502) and the chip flow rate value (obtained in operation 506). In some implementations, the controller 240 (1) determines the fluid leakage value by calculating the sum of the black liquor flow rate value, the white liquor flow rate value, the chip chute circulation flow rate value, and the high-pressure feeder purge flow rate value, and (2) reduces the make-up liquor flow rate value by the calculated sum to obtain the fluid leakage value (e.g., by calculating the difference between the make-up liquor flow rate value and the calculated sum of the flow rates values).

[0071] The controller 240 determines whether the fluid leakage meets a leakage threshold. The leakage threshold can be a single numeric value or a range. If the controller 240 determines (510) that the fluid leakage meets (e.g., exceeds) the leakage threshold (e.g., greater than a single numeric threshold or greater than the upper limit of a threshold range), the controller 240 adjusts (e.g., decreases) (512) the annular gap (e.g., gap width) between the pocket rotor 204 and the chamber 206. On the other hand, if the controller 240 determines (510) that the fluid leakage does not meet (e.g., is less than) the leakage threshold (e.g., less than a single numeric threshold or less than the lower limit of a threshold range), the controller 240 adjusts (e.g., increases) the annular gap 222 between the pocket rotor 204 and the chamber 206.

[0072] In either case, to make the appropriate adjustment, the controller 240 can maintain a lookup table that stores a correlation between leakage amounts and corresponding widths of the gap 222. In such implementations, the controller 240 uses the determined fluid leakage to look up the corresponding gap width to apply via the lookup table. In other implementations, the appropriate adjustment to the width of the gap 222 can be determined using a set of stored rules that depend on multiple factors, such as (e.g., current gap width, current axial position of the pocket rotor, current chamber position, desired fluid leakage amount, etc.).

[0073] Based on the determined adjustment to the annular gap 222, the controller 240 sends a signal (e.g., a desired axial rotor position) to the controller assembly 402 to implement the determined adjustment to the width of the gap 222, for example, by moving the pocket rotor axially relative to the chamber, as described with reference to FIG. 4. Based on the signal received from the controller 240, the controller assembly 402 adjusts the annular gap 222, and in doing so, adjusts the fluid leakage through the gap 222 and the low-pressure outlet of the HPF 112.

[0074] FIG. 6 is a block diagram of computing devices 600, 650 that can be used to implement the systems and methods described herein, either as a client or a server or multiple servers.

[0075] Computing device 600 is intended to represent various forms of digital computers, such as laptops, desktops, workstations, personal digital assistants, servers, blade servers, mainframes, and other suitable computers. Computing device 650 is intended to represent various forms of mobile devices, such as personal digital assistants, mobile phones, smartphones, smart watches, head-worn devices, and other similar computing devices. The components illustrated herein, their connections and relationships, and their functionality are for illustrative purposes only and do not limit the implementations described and / or claimed herein.

[0076] Computing device 600 includes a processor 602, memory 604, storage device 606, a high-speed interface 608 connecting to memory 604 and a high-speed expansion port 610, and a low-speed interface 612 connecting to a low-speed bus 614 and storage device 606. Each of the components 602-612 is interconnected using various buses and may be mounted on a common motherboard or otherwise, as desired. Processor 602 processes instructions for execution within computing device 600, including instructions stored in memory 604 or storage device 606, and can display graphical information for a GUI on an external input / output device, such as a display 616 coupled to high-speed interface 608. Other implementations can use multiple processors and / or multiple buses, along with multiple memories and memory types, as desired. Multiple computing devices 600 can also be connected, with each device providing a portion of the required operations (e.g., as a server bank, a group of blade servers, or a multiprocessor system).

[0077] The memory 604 stores information within the computing device 600. In one implementation, the memory 604 is a computer-readable medium. In one implementation, the memory 604 is one or more volatile memory units. In another implementation, the memory 604 is one or more non-volatile memory units.

[0078] The storage device 606 can provide mass storage for the computing device 600. In one implementation, the storage device 606 is a computer-readable medium. In various different implementations, the storage device 606 can be a hard disk device, an optical disk device, or an array of devices including a tape device, a flash memory, or other similar solid-state memory device, or devices in a storage area network or other configuration. In one implementation, a computer program product is tangibly embodied in an information medium. The computer program product includes instructions that, when executed, perform one or more methods, such as those described above. The information medium is a computer- or machine-readable medium, such as the memory 604, the storage device 606, or memory on the processor 602.

[0079] The high-speed controller 608 manages bandwidth-intensive operations of the computing device 600, and the low-speed controller 612 manages less bandwidth-intensive operations. Duty division is an example. In one implementation, the high-speed controller 608 is coupled to the memory 604, the display 616 (e.g., via a graphics processor or accelerator), and a high-speed expansion port 610 that can accept various expansion cards (not shown). In an implementation, the low-speed controller 612 is coupled to the storage device 606 and the low-speed expansion port 614. The low-speed expansion port, which includes various communication ports (USB, Bluetooth, Ethernet, wireless Ethernet, etc.), can connect to one or more input / output devices such as a keyboard, pointing device, scanner, or network devices such as a switch or router via a network adapter.

[0080] Computing device 600, as shown, may be implemented in several different forms. For example, it may be implemented as a standard server 620, or multiple times in a group of such servers. It may be implemented as part of a rack server system 624. It may also be implemented in a personal computer, such as a laptop computer 622. Alternatively, components from computing device 600 may be combined with other components in a mobile device (not shown), such as device 650. Each such device may include one or more of computing devices 600, 650, and the overall system may be made up of multiple computing devices 600, 650 communicating with each other.

[0081] Computing device 650 includes components such as a processor 652, memory 664, input / output devices such as a display 654, a communications interface 666, and a transceiver 668. Device 650 may also be provided with storage devices such as a microdrive or other device to provide additional storage. Each of components 650-668 are interconnected using various buses, and some of the components may be mounted on a common motherboard or otherwise, as desired.

[0082] The processor 652 can process instructions for execution within the computing device 650, including instructions stored in the memory 664. The processor may include separate analog and digital processors. The processor can provide, for example, control of a user interface, applications executed by the device 650, and coordination of other components of the device 650, such as wireless communication by the device 650.

[0083] The processor 652 can communicate with a user via a display interface 656 coupled to the control interface 558 and the display 654. The display 654 may be, for example, a TFT LCD display or an OLED display, or other suitable display technology. The display interface 656 can include appropriate circuitry for driving the display 654 to present graphical and other information to the user. The control interface 658 can receive commands from the user and convert them for transmission to the processor 652. Additionally, an external interface 662 can be provided in communication with the processor 652 to enable short-range communication between the device 650 and other devices. The external interface 662 can provide, for example, wired communication (e.g., via a docking procedure) or wireless communication (e.g., via Bluetooth or other such technology).

[0084] The memory 664 stores information within the computing device 550. In one implementation, the memory 664 is a computer-readable medium. In one implementation, the memory 664 is one or more volatile memory units. In another implementation, the memory 664 is one or more nonvolatile memory units. Expansion memory 674 is also provided and connected to the apparatus 650 via an expansion interface 672, including, for example, a SIMM card interface. Such expansion memory 674 can provide additional storage space for the device 650 or can store applications and other information for the device 650. Specifically, the expansion memory 674 can include instructions for performing or supplementing the processes described above and can also include secure information. Thus, for example, the expansion memory 674 can be provided as a security module for the device 650 and can be programmed with instructions that enable secure use of the device 650. Furthermore, secure applications may be provided via a SIMM card, along with additional information, such as placing identifying information on the SIMM card in a manner that cannot be hacked.

[0085] As described below, the memory may include, for example, flash memory and / or MRAM memory. In one implementation, a computer program product is tangibly embodied in an information medium. The computer program product includes instructions that, when executed, perform one or more methods, such as those described above. The information medium is a computer- or machine-readable medium, such as memory 664, expansion memory 674, or memory on processor 652.

[0086] Device 650 can communicate wirelessly via a communication interface 666, which may optionally include digital signal processing circuitry. Communication interface 666 may provide for communication under various modes or protocols, such as GSM voice calls, SMS, EMS, or MMS messaging, CDMA, TDMA, PDC, WCDMA, CDMA2000, or GPRS. Such communication may occur, for example, via a radio frequency transceiver 668. Short-range communication may also occur, such as using a transceiver (not shown), such as Bluetooth or Wi-Fi. Additionally, a GPS receiver module 670 may provide additional wireless data to device 650, which may be used appropriately by applications executing on device 650.

[0087] Device 650 may also communicate audibly using voice codec 660, which may receive spoken information from a user and convert it into usable digital information. Voice codec 660 may likewise generate audible sounds for the user, such as through a speaker in the handset of device 650. Such sounds may include sounds from a voice call, may include recorded sounds (e.g., voice messages, music files, etc.), and may also include sounds generated by applications running on device 650.

[0088] The computing device 650 may be implemented in many different forms, as shown in the figure, for example, as a mobile phone 680, or as part of a smartphone 682, personal digital assistant, or other similar mobile device.

[0089] Various implementations of the systems and techniques described herein can be realized in digital electronic circuitry, integrated circuits, specially designed ASICs, computer hardware, firmware, software, and / or combinations thereof. These various implementations can include implementations in one or more computer programs executable and / or interpretable on a programmable system including at least one programmable processor, either special purpose or general purpose, coupled to a storage system to receive data and instructions and to transmit data, at least one input device, and at least one output device.

[0090] These computer programs, which may also be referred to as programs, software, software applications, or code, contain machine instructions for programmable processors and may be implemented in high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. As used herein, the terms "machine-readable medium" and "computer-readable medium" refer to any computer program product, apparatus, and / or device, such as a magnetic disk, optical disk, memory, programmable logic device (PLD), that provides machine instructions and / or data to a programmable processor, including a machine-readable medium that receives the machine instructions as a machine-readable signal. The term "machine-readable signal" refers to any signal used to provide machine instructions and / or data to a programmable processor.

[0091] To provide for user interaction, the systems and techniques described herein can be implemented on a computer that has a display device, such as a CRT (cathode ray tube) or LCD (liquid crystal display) monitor, for displaying information to the user, and a keyboard and pointing device (such as a mouse or trackball) that allows the user to provide input to the computer. Other types of devices can also be used to provide for user interaction. For example, feedback provided to the user can be any form of sensory feedback, such as visual feedback, auditory feedback, or tactile feedback, and input from the user can be received in any form, including acoustic, speech, or tactile input.

[0092] The systems and techniques described herein can be implemented in a computing system that includes back-end components, e.g., as data servers, or includes middleware components such as application servers, or includes front-end components, such as clients having a graphical user interface or web browser through which a user can interact with an implementation of the systems and techniques described herein, or any combination of such back-end, middleware, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication, such as a communications network. Examples of communications networks include a local area network ("LAN"), a wide area network ("WAN"), and the Internet.

[0093] A computing system may include clients and servers. Clients and servers are typically remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other.

[0094] As used herein, the term "module" is intended to include, but is not limited to, one or more computers configured to execute one or more software programs containing program code that causes the processing units / devices of the computer to perform one or more functions. The term "computer" is intended to include any data processing or computing device / system, such as a desktop computer, laptop computer, mainframe computer, personal digital assistant, server, handheld device, smartphone, tablet computer, e-reader, or other electronic device capable of processing data.

[0095] A number of embodiments have been described. Nevertheless, it will be understood that various modifications can be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims. While the specification contains many specific implementation details, these should not be construed as limitations on the claims, but rather as descriptions of functionality specific to particular embodiments. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment.

[0096] Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Further, while features may be described above as working in a particular combination, and may even initially be claimed as such, in some cases one or more features from the claimed combination may be deleted from the combination, and the claimed combination may be directed to a subcombination or variation of the subcombination.

[0097] Similarly, while operations are shown in the figures in a particular order, this should not be understood as requiring such operations to be performed in the particular order or sequential order shown, or that all of the operations shown be performed, to achieve desirable results. In some cases, multitasking or parallel processing may be advantageous. Furthermore, the separation of various system modules and components in the above-described embodiments should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems may generally be integrated into a single software product or packaged into multiple software products.

[0098] Specific embodiments of the subject matter have been described. Other embodiments are within the scope of the claims. For example, the actions recited in the claims may be performed in a different order and still achieve desirable results. As an example, some processes depicted in the accompanying figures do not necessarily require the particular order or sequential order shown to achieve desirable results. [Explanation of symbols]

[0099] 100 Supply System 102 Chip Speed ​​Encoder 104 Wood chips 106 Chip Shot 108 Conduit 110 Supply System 112 High Pressure Feeder (HPF) 114 High-Pressure Pipe 116 Low pressure outlet 118 Pump 120 Conduit 122 High pressure inlet 130 Chip chute circulation flow meter 134 White liquid flowmeter 136 Replenishment liquid flow meter 138 Conduit 140 Separator 142 Pump 144 Liquid separator 150 Conduit 152 Level Tank 154 Replenishment pump 160 Conduit 162 Conduit 202 Fixed Housing 204 Pocket Rotor 206 Cylindrical Chamber 208 High pressure outlet 210 Low pressure inlet 214 Drive shaft 216 Through pocket 220 Opening 222 Gap 230 Bell Chamber 232 Conduit 240 Computer Controller

Claims

1. 1. A method for controlling fluid leakage in a high pressure feeder of a supply system, the method comprising: obtaining a plurality of flow rates from a plurality of flow meters, the plurality of flow rates including: (1) a make-up liquor flow rate value specifying the flow of make-up liquor to a digester; (2) a black liquor flow rate value specifying the flow of black liquor to the feeding system; (3) a white liquor flow rate value specifying the flow of white liquor to the feeding system; (4) a chip chute circulating flow rate value specifying the flow of low-pressure circulating liquor from a low-pressure outlet of the high-pressure feeder; and (5) a high-pressure feeder purge flow rate value specifying the flow of white liquor to a high-pressure inlet of the high-pressure feeder; obtaining a chip speed using a chip speed encoder that identifies the rate at which wood chips are fed into the high pressure feeder; using the tip velocity to determine a tip flow rate value specifying the flow of chips supplied to the high pressure feeder; determining a fluid leakage value identifying an amount of fluid leakage through a gap between a pocket rotor and a housing of the high-pressure feeder using the plurality of flow rates and the tip flow rate value; determining that the fluid leak satisfies a leak threshold; adjusting an annular gap between the pocket rotor and the housing in response to determining that the fluid leakage satisfies the leakage threshold; A method comprising:

2. determining a fluid leakage value using the plurality of flow rates and the tip flow rate value, calculating a sum of the black liquor flow rate value, the white liquor flow rate value, the chip chute circulation flow rate value, and the high-pressure feeder purge flow rate value; reducing the makeup fluid flow rate value by the calculated sum to obtain the fluid leakage value; The method of claim 1 , comprising:

3. The method of claim 1 , wherein adjusting the annular gap between the pocket rotor and the housing comprises moving the pocket rotor into the housing.

4. 4. The method of claim 3, wherein the pocket rotor is coaxial with the housing, and the step of moving the pocket rotor into the housing comprises moving the pocket rotor axially relative to the housing.

5. determining the chip flow rate value specifying the flow of chips supplied to the high pressure feeder; 2. The method of claim 1, comprising the steps of: (1) scaling the chip meter rate by a wood chip volumetric capacity that specifies the amount of wood chips being fed to the high-pressure feeder at the chip meter rate; and (2) scaling the chip meter rate by a discharge value that specifies the rate at which air is expelled from the wood chips fed to the high-pressure feeder.

6. 1. A system comprising: one or more memory devices for storing instructions; one or more data processing devices configured to interact with said one or more memory devices and, upon executing said instructions, perform operations to control fluid leakage in a high pressure feeder of a supply system; Equipped with receiving a content request from a client device; obtaining a plurality of flow rates from a plurality of flow meters, the plurality of flow rates including: (1) a make-up liquor flow rate value specifying the flow of make-up liquor to a digester; (2) a black liquor flow rate value specifying the flow of black liquor to the feeding system; (3) a white liquor flow rate value specifying the flow of white liquor to the feeding system; (4) a chip chute circulating flow rate value specifying the flow of low-pressure circulating liquor from a low-pressure outlet of the high-pressure feeder; and (5) a high-pressure feeder purge flow rate value specifying the flow of white liquor to a high-pressure inlet of the high-pressure feeder; obtaining a chip speed using a chip speed encoder that identifies the rate at which wood chips are fed into the high pressure feeder; using the tip velocity to determine a tip flow rate value specifying the flow of chips supplied to the high pressure feeder; determining a fluid leakage value identifying an amount of fluid leakage through a gap between a pocket rotor and a housing of the high-pressure feeder using the plurality of flow rates and the tip flow rate value; determining that the fluid leak satisfies a leak threshold; adjusting an annular gap between the pocket rotor and the housing in response to determining that the fluid leakage satisfies the leakage threshold; Including, the system.

7. determining a fluid leakage value using the plurality of flow rates and the tip flow rate value, calculating a sum of the black liquor flow rate value, the white liquor flow rate value, the chip chute circulation flow rate value, and the high-pressure feeder purge flow rate value; reducing the makeup fluid flow rate value by the calculated sum to obtain the fluid leakage value; The system of claim 6, comprising:

8. The system of claim 6 , wherein adjusting the annular gap between the pocket rotor and the housing comprises moving the pocket rotor into the housing.

9. 7. The system of claim 6, wherein the pocket rotor is coaxial with the housing, and wherein moving the pocket rotor into the housing comprises moving the pocket rotor axially relative to the housing.

10. determining the chip flow rate value specifying the flow of chips supplied to the high pressure feeder, 7. The system of claim 6, including the step of scaling the chip meter rate by (1) a wood chip volumetric capacity that specifies the amount of wood chips being fed to the high-pressure feeder at the chip meter rate, and (2) a discharge value that specifies the rate at which air is expelled from the wood chips fed to the high-pressure feeder.

11. 1. A non-transitory computer readable medium storing instructions that, when executed by one or more data processing devices, cause the one or more data processing devices to perform operations to control fluid leakage in a high pressure feeder of a supply system, the instructions comprising: obtaining a plurality of flow rates from a plurality of flow meters, the plurality of flow rates including: (1) a make-up liquor flow rate value specifying the flow of make-up liquor to a digester; (2) a black liquor flow rate value specifying the flow of black liquor to the feeding system; (3) a white liquor flow rate value specifying the flow of white liquor to the feeding system; (4) a chip chute circulating flow rate value specifying the flow of low-pressure circulating liquor from a low-pressure outlet of the high-pressure feeder; and (5) a high-pressure feeder purge flow rate value specifying the flow of white liquor to a high-pressure inlet of the high-pressure feeder; obtaining a chip meter speed using a chip meter speed encoder to identify the rate at which wood chips are being fed into the high pressure feeder; using the chip meter velocity to determine a chip flow rate value specifying the flow of chips supplied to the high pressure feeder; determining a fluid leakage value identifying an amount of fluid leakage through a gap between a pocket rotor and a chamber of the high-pressure feeder using the plurality of flow rates and the tip flow rate value; determining that the fluid leak satisfies a leak threshold; adjusting an annular gap between the pocket rotor and the chamber in response to determining that the fluid leakage satisfies the leakage threshold; 1. A non-transitory computer-readable medium comprising:

12. determining a fluid leakage value using the plurality of flow rates and the tip flow rate value, calculating a sum of the black liquor flow rate value, the white liquor flow rate value, the chip chute circulation flow rate value, and the high-pressure feeder purge flow rate value; reducing the makeup fluid flow rate value by the calculated sum to obtain the fluid leakage value; 12. The non-transitory computer-readable medium of claim 11, comprising:

13. 12. The non-transitory computer-readable medium of claim 11, wherein adjusting the annular gap between the pocket rotor and the chamber comprises moving the pocket rotor into the chamber.

14. 14. The non-transitory computer-readable medium of claim 13, wherein the pocket rotor is coaxial with the chamber, and moving the pocket rotor into the chamber comprises moving the pocket rotor axially relative to the chamber.

15. determining the chip flow rate value specifying the flow of chips supplied to the high pressure feeder, 12. The non-transitory computer-readable medium of claim 11, comprising scaling the chip meter rate by (1) a wood chip volumetric capacity that specifies the amount of wood chips being fed to the high-pressure feeder at a chip meter rate, and (2) a discharge value that specifies the rate at which air is expelled from the wood chips fed to the high-pressure feeder.

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