FI106974B - Operating system for a pump and procedure for operating a pump - Google Patents

Description

106974

Pump control system and method of pump control

The invention relates to a pump control system and a method for controlling a pump. More particularly, the invention relates to a control system for a suction pump for removing fluid and a method for controlling said pump. The suction pump system used in the invention can be used e.g. paper, board and pulp drying machines; various pulp mill suction filters and scrubbers. In general, the pump control system of the invention is applicable to all applications where the gas, liquid or mixture thereof is sucked through a perforated or wire surface.

10

The use of various suction systems as a means of filtration and precipitation is well known not only in the paper and wood processing industry, but also, for example, in the mining and leaching industries. Suction systems are used for both various wire filters and dryers, which can be considered as paper, board and pulp drying machines, as well as 15 different suction disc or suction drum filters. It has long been known to use a suction foot as a suction system. the weight of the filtrate flowing into the suction foot, which is substantially vertical to the tube, creates the necessary vacuum. Since it is virtually impossible to control the vacuum created by the suction foot, various vacuum pumps have been introduced, the most common of which is the so-called vacuum pump. water ring-20 pump. The water ring pump typically generates a constant vacuum. However, it is possible to adjust the suction capacity of the water-ring pump based on the fact that the capacity of the pump is also constant. In other words, the amount of gas drawn from the suction point can be varied by introducing additional air into the pump.

».. * · * 25 The latest option for suction equipment is the so-called suction device. a high speed vacuum pump, which is in fact a centrifugal pump for gas pumping, the use of which in papermaking dewatering is described in Fl patent 97244. This publication discloses e.g. a problem that occurs when a papermaking machine's fabric, blanket, or «· · J,: · wire tends to become clogged over time. In other words, the permeability of the tissue changes with its service life. The document solves this problem by: • · ·. it is known how much liquid should be removed from the suction unit, for example, from the suction box or group «·«, measured by the amount of liquid removed from that suction unit ...., compared to the target value and adjusted accordingly. This is most easily accomplished by adjusting the vacuum pump rotation speed because .. · 35, for example, increasing the rotational speed increases both the vacuum pump volume flow rate and the vacuum level. The second control alternative is to control both the rotational speed and the output of the vacuum pump, i.e., the flow rate.

One problem with the solution disclosed in that publication is that the system includes a mechanical device, a flow meter, on the basis of which the operation of the system is controlled. Such a device is not only an additional investment but also vulnerable to damage, at least in long-term use, whereby the accuracy of any papermaking or similar process is compromised. In addition, the use of a flow meter alone does not add any value to the system, but other interesting issues such as condition monitoring of the suction target, felt 10 or the like, determining the need for changing the felt, etc. remain a dream.

US 4,329,201 deals with dewatering from a web on a wire. According to the publication, for example, water post can be used. keskipakoistyhjöpumppua. In Ki-15, the idea is to strive to use constant vacuum for dewatering. This is achieved, according to the publication, by the fact that the dewatering devices include two dewatering dents over which the wire passes. In the case of a new wire, only one of the second drainage tubes is used, but as the vacuum increases, the second tube is opened and the suction device suction is also directed through the second tube to the wire. The solution 20 of the publication also utilizes a control valve which, together with the vacuum control, maintains a constant negative pressure on the suction devices. The publication also mentions how the wire dwell time at each suction tube can be increased, if necessary, either by increasing, widening the suction slot in the suction tube or slowing the wire speed.

• · · · 25 • · • ·

In other words, the publication seeks to account for changes in the permeability of the wire during its lifetime, either by adding suction devices, changing their suction widths, or changing suction time.

• · ·. ···. 30 U.S. Pat. No. 4,466,873, as in the previous publication, deals with the drawing wire of the flat wire section of a papermaking machine. removal. The equipment of this patent employs a variable speed vacuum pump, «· ·. ·. which can also be a centrifugal vacuum pump. The system aims to control the water supply in two • cycles so that during the first cycle the pump speed is p-. * is determined as constant, whereby the pump generates sufficient vacuum for web dewatering. As the wire • ·: * ·· 35 gradually becomes clogged, the vacuum in the suction boxes increases. When the vacuum in the last suction cup • · 3 106974 has increased to a predetermined value, the control unit instructs the vacuum pump to lower the rotational speed so that the vacuum remains at its aforementioned smax.

5 Although the solution of the publication takes into account the effects of wire clogging, it does not teach the supply of two resistance curves to the control unit and, of course, their use so that the wire life can be optimized if desired.

U.S. Patent 4,518,318 discloses the control of an electric motor and a central fire 10 pump attached thereto under various operating conditions. At several points in the publication, for example, pumps for central heating systems are controlled, whose operation, mainly rotational speed, is controlled in relation to the thermostatic valves in the water radiators. The publication promises how the lifting height is entered into the pump control unit - volumetric flow co-ordinate, both constant pump speed curves and so-called pump speeds. modulaatiokäyrät. The Mocli-15 draft curve is a curve that adjusts the lift height and volume flow as the pump speed changes.

Ao. the problem addressed in the publication is power losses when the flow conditions in the network are changed. A solution to this is the modification of the pump speed according to the flow conditions. The document teaches in detail, starting with column 4, line 30, how the pumping system is dimensioned for flow rate Qx and lift height

Hx, which corresponds to a situation where all thermostatic valves in the central heating piping are open. In partial load cases where the valves are throttled or closed by a pump; pun should follow the curve Hr (Q). This is programmed in the pump control unit s · · · 25 so that, for example, when several valves close, the pressure (= lifting height) in the pipes • · · · ·. the flow rate increases, and the flow rate decreases accordingly, if the pump speed remains constant. In other words, in figure two, the constant speed curve is to the left.

• · · *;!; * Switching points are supplied to the pump control system for each constant speed curve «« * *** so that, for example, when the system pressure rises to 57, the system drives the pump drive motor to decrease its speed. The corresponding 6- • · ;;; * control system can control the pump to increase its speed if in the event of a load, one or more valves are opened.

I ·

In other words, U.S. Patents 4,329,201 and 4,466,853, discussed above, deal with, but do not resolve, paper-35 nanoparticle dewatering and wire-change issues by utilizing a pump characteristic. In the latter of these two publications, only the dependence between pump suction and rotational speed is known and exploited. US Patent 4,518,318 and DE 196 18 462, on the other hand, deal with the utilization of the characteristic diagram, but both in a different way and for a different purpose than in our next more detailed invention.

The use of a suction pump system will now be described in more detail by way of example in connection with a vacuum system for a paper machine. The uses of both the prior art suction pump systems and the method and suction pump system of the present invention fall into two groups.

In the first group, the lymphatic site has both a tissue and a mass pathway. In these cases, the flow resistance when running at the same mass is almost constant regardless of the felt resistance, since the resistance of the mass path is dominant. The flow resistance changes significantly when the paper type is changed. The traditional usage is to determine a constant vacuum level for each paper grade, which is then followed while driving. Typical suction targets include flat forming boxes for the forming section of a paper, board and pulp drying machine, various suction rolls with a forming section and a press section, and various vacuum filters for causticizing the pulp mill and e.g. fertilizers and base metals.

20

In the second group, the lymphatic system has only tissue. As a result, the flow resistance increases as the tissue ages due to fouling and tissue compression. Typical suction targets are e.g. paper machine felt refinishing suction boxes.

: These suction boxes on the press section of the paper machine remove water from the fabric by · · · 25 suctioning air through it. Felting has three main functions: • · ·: · * 1) dewatering (some of the water in the tissue has moved from the paper web to the fabric [* with press section), • · e 2) cleaning (some of the water comes from wash jets to clean the tissue), and 3)

• · I

* · '* Maintains a consistent moisture profile in the fabric across the machine.

30 Traditionally, in such applications, a vacuum pump has been used such that the vacuum pump • · * ;;; the bun is absorbed through the tissue at a constant volume flow, which increases the vacuum level as the tissue ··· * ages. This type of driving is automatically achieved by a displacement type ·. * ·· vacuum pump, eg liquid ring pump.

«« «· •« · 106974

However, the purpose of felt rebuilding is not to maximize dewatering of the tissue, since too dry tissue will not function properly in dewatering of the press nip. The amount of air to be absorbed through the tissue in the suction box is selected so that a suitable moisture ratio remains in the tissue. The moisture ratio is the ratio of the weight of water in the tissue to the weight of the tissue. Too much airflow leads to too low a moisture ratio and too little airflow to a correspondingly too high humidity ratio. In practice, however, it has been found that the driving mode based on the constant volume flow described above does not achieve the optimum humidity ratio, but the humidity ratio even varies to an adverse degree.

10

One solution to the above problem has proven to be a way of adjusting the vacuum level of the felt refinement by measuring the tissue moisture after the suction box and trying to keep the moisture desired by adjusting the vacuum pump rotation speed and output point.

15 Another possible way to solve the problem is to measure the amount of water leaving the suction box and the amount of shower water and use it to estimate the moisture and required vacuum of the felt. However, the problem becomes the estimation of the amount of water transferred from the web to the nip in the press nip, which, however, is far from being of the same order as the variations in the humidity ratio of the constant volume flow.

In the pursuit of optimum driving by paper or similar machines in a situation where the suction target has both a tissue and a pulp path, prior art 4 4 '·' operates by dewatering directly from the pulp by suctioning air through the pulp and the tissue.

• · · •; * j 25 The purpose of a paper machine is to remove as much water as possible from the pulp • • ·; · [Dewatering section, as the cost of mechanical dewatering (pressing and suction)] * is only about a quarter of the cost of dewatering dewatering.

• · ·

However, dewatering should be gradual. For the first suction sites, i.e., • · · * · * * sites where the web is at its humidest, too high a vacuum level cannot be used, 30 as this would over-compact the pulp web and weaken dewatering in later stages. Traditionally, the vacuum level has been kept constant at each suction point.

• · ·· / 'The selected vacuum depends on the type of mass being run.

«« · *: With constant speed liquid ring vacuum pumps, the vacuum level is controlled by a vacuum 35 control valve that delivers the required amount of outdoor air to the suction system. This type of control is very problematic when wasting energy, because part of the vacuum pump's capacity is used to pump outdoor air.

In this prior art paper machine technology, suction systems based on the use of water ring pumps 5 have generally been based on technology whereby the vacuum created by the suction pump, or at least the amount of water to be removed by it, is empirically controlled. For example, the flat wire section of a papermaking machine has traditionally been adjusted to the gloss of the pulp web. This has been done so that the user of the paper machine, based on his experience, knows at what point in the level-10 wire section the pulp gloss should begin to cloud. In practice, the gloss clouding means that there is no longer a uniform film of water on the surface of the web, but the amount of water in the web has been reduced to such an extent that almost all of the water will fit inside the web. As the felt of the papermaking machine begins to clog, the shiny portion of the web becomes longer, so the operator knows that the vacuum level should be increased to absorb the desired amount of fluid from the 15 webs. However, this type of control is not the best possible because it requires close monitoring and nevertheless is not the most accurate way to monitor fluid removal. Also, this tracking method does not give a clear indication that the tissue machine fabric should be replaced, but the replacement is again empirical, most often based on the fabric life. In other words, each tissue is assigned a practical lifetime after which the tissue is replaced regardless of its actual condition.

With an adjustable velocity medium in the suction system of the invention; · 'S suction vacuum pump can be used to adjust the pump speed by adjusting the pump rotation speed by 25 clubs to optimize the power required to generate the desired vacuum and reduce power consumption ♦ · 1 ·: · 1 with lower vacuum levels than prior art solutions.

V.1 One of the most optimal driving methods for such a system according to the invention is to measure the moisture of the paper web after the press section before the drying section and to seek to maximize the dry matter content by simultaneously adjusting the vacuum at all suction points. An appropriate vacuum level at each suction target and the vacuum ratio between the various suction targets may be obtained, for example, by means of a learning control system and fuzzy logic.

* «· •» «P1462; Horo et al.

· «4 • ♦ 1 4 106974

Another way to control dewatering activity is to measure the amount of water discharged, for example, as disclosed in Fl 9797, and to adjust the vacuum levels accordingly. It is essential that the aim is not to maximize the drainage of a single inlet, but the total amount of water discharged from each inlet.

5

Further, the suction system according to the invention and the method applied thereto are also capable of being applied to tissue condition monitoring. As noted above, changes in tissue permeability occur during tissue use, due to both tissue obstruction and compression. A sufficiently large change in permeability to Permeabi-10, possibly in combination with other results, such as track and / or tissue humidity, indicates a need for tissue replacement.

As another aspect of tissue condition monitoring, our invention enables tissue trend monitoring (lifetime tracking of tissue), which enables the comparison of different tissues, thereby helping to find the best tissue type for each application. In other words, our invention makes it possible to compare, for example, paper machine fabrics of different manufacturers or paper machine fabrics of different materials, as well as the suitability of different fabrics for different pulps.

20

The invention also makes it possible to monitor and alert the operating condition of the pump, e.g., contamination, based on the measurement of the pump and its operation from the suction system and the characteristic diagram of the new pump introduced into the system.

The new suction pump system according to the invention, already consisting of a speed controlled variable suction pump, a suction unit and a measuring and control system Fl * ', as discussed in the above patent Fl · · · · · · · * presented the disadvantages of prior art systems and seeks to optimize the drainage of various applications. Kek- • · · • · ·. * · * 'Suction pump system is characterized by utilizing 30 different types of suction pump information such as pump rotation • M «· - * ··· * breast speed, pump power, pump torque, etc.

As a state of the art, US-A-4 108 574 discloses a solution which discloses a pump which determines two variables affecting the flow of the pump, for example power, rotational speed and / or control over the pump. · · 8 106974. When this data is combined with the measured flow rate data during the test run, the pump has a characteristic curve that no longer requires the pump flow rate to be measured in actual operation, but by using the two flow-related variables mentioned above. Going a bit further, the publication has made it possible to use the pump as a "consistency meter" for the pulp industry, for example, as consistency is one of the flow variables that can be determined from test runs. This publication explains the further treatment of the infusion from the pump in great detail and in many respects applicable to our present invention, of course, with the objectives and starting points clearly different from our US patent.

15 However, that publication refers, first, to the treatment of liquids. Second, the publication in no way interferes with what happens on the suction side of the pump. The only thing needed on the suction side of the pump is the "starting value" for the differential pressure generated by the pump.

It is characteristic of the system according to the present invention, for example in connection with a paper machine, that in operation, ·. From this (for example, pump speed and torque or power), the flow of pumped air is calculated. Based on the airflow and the measured vacuum level, it is still possible to · · calculate the total permeability of the tissue on the suction box or between the tissue and the paper web. This can be followed as a function of time in the tissue or paper path. ·; ·. • • · 30 and make any necessary changes to the process or tissue repair automatically.

• «I <«

«I

According to a preferred embodiment of the invention, the suction target resistor function, or so-called resistor curve, is stored in the memory of the pump control unit / central unit. The resistor function is stored in two different situations. First, a resistor function f 1 is stored in the memory of the control / central unit, comprising a baseline with felt fabric F1462; Horo et al.

• · 9 106974 or the filter material through which the medium is aspirated by the pump is new and clogged. According to the invention, a resistor curve or resistor function f2 is also stored in the memory of the central unit, which otherwise comprises the same resistor components, but now the material to be sucked in, such as tissue or filter material, has been used and clogged. Said resistance functions are monitored during operation of the suction pump system in relation to the pump operating point (rotational speed, the achieved vacuum level at the suction side of the pump and the flow rate of the pumped material reached, e.g. m3 / time unit). The pump operating point is called the intersection of the resistance curve and the rotation speed curve. Thus, it is sought to distribute the pump in Ohio so that its operating point remains within the permissible range (between the graphs of the resistor functions) in the volumetric flow pressure coordinate system. The pump may also be controlled by adjusting, for example, the cleaning of the tissue paper tissue (i.e., if the resistance curve rises, the use of wash jets may be enhanced or multiple wash jets may be used) and / or pump rpm may be adjusted and pump rpm increased.

According to another preferred embodiment of the invention, the resistor functions fa, fb, fc ... of the different felt types can be stored in the memory of the pump control / central unit 100 and the stored functions fa, fb, fc ... can be enabled from the pump central memory each time the felt type is changed. . Of course, pairs of resistor functions, that is, resistor functions on both new and blocked felts, can also be stored. Long-term trend tracking between different types of felts can also be performed and, based on that trend tracking, the most appropriate felt for each paper / board mass can be selected.

e <• ♦ 25 * * · ♦ ·

The control system and method of the suction pump according to the invention is characterized by what is stated in the appended claims.

• • • • • • • • 1

The invention will now be described with reference to the accompanying drawings, in which some preferred embodiments of the invention are shown, but are not intended to be limited thereto.

«« P1462; Horo et al.

«· ·. Figure 1A shows the yield curve of a centrifugal vacuum pump, the so-called. characteristic. Horizontal. the shaft represents the volumetric flow rate and the vertical axis the vacuum level reached by the pump suction. 35 sides. The graphs G1, G2, G3 are torque curves and the graphs D1, D2, D3 are 10,106,974 rpm curves. At a given torque and at a certain speed, a certain amount of flow is achieved and a certain level of vacuum is still achieved.

Figure 1B illustrates the determination of the pump output point in a co-ordinate system of 5, showing the suction pump volume flow on the horizontal axis and the vacuum on the suction side of the pump on the vertical axis. In the coordinate system, the graphs f, and f2 of the above-mentioned resistance functions and the displacement graph E of the pump output point are plotted.

Fig. 1C illustrates a suction pump according to the invention and associated control / measurement devices according to a preferred embodiment of the invention.

Fig. 2A illustrates a system according to another preferred embodiment of the invention in connection with a paper machine felt refining suction box.

15

Figure 2B illustrates a system of the type shown in Figure 2A by way of example in a so-called paper machine. in connection with the suction box of the wire section, in which the felt and pulp web of the paper machine together form a resistance which is monitored in the system according to the invention.

Figure 2C shows a suction pump system according to a third preferred embodiment of the invention, arranged in an exemplary manner in connection with a suction filter for the cellulose industry.

Figure 2D is a block diagram showing the operation of a suction pump system according to the invention.

«·« · • · · · · · ·

Figure 1A shows the yield or characteristic curve of a suction pump in a coordinate system, where • · the horizontal axis has the suction pump output or volume flow (gas flow through the suction pump) and • · · the vertical axis represents the vacuum generated by the suction pump. The suction pump 10 is preferably a centrifugal vacuum pump. The figure shows both constant speed curves D1, D2, D3 ... and constant. ·, Torque curves G1, G2, G3 .... As shown in the figure, there is a given torque · ···. bridges for rotation are almost always a unique intersection. By performing volume # and vacuum measurements under test conditions by varying both pump speed and pump torque (or power output if desired), the characteristic curve of FIG. 1A can be fed to the memory of the pump control unit 35 / CPU. Pump 10 • ·

Pl462; Horo et al.

The 106974 output point (volumetric flow and vacuum level) can then be determined by simply measuring the pump 10 torque (or power) and rotational speed, i.e. its rotational speed.

Under practical conditions, the actual vacuum level achieved by the pump can be further measured, which can be used to check the pump's output point and determine whether the pump's performance has changed as a result of wear or contamination, for example.

The pump output curves can be corrected, if necessary, by further measuring the temperature and humidity of the medium to be sucked, since they affect the output values in a manner known per se.

1B, the vacuum pump yield point is already determined by the suction system resistance curve f along with rotation speed D in the coordinate system already known from the previous figure. The yield point is located at the intersection of the rotation speed graph D and 15 of the resistance curve f. The shape of the resistance curve f depends on how much air is passed through the suction system at different vacuum levels. The shape of the resistance curve, i.e. the flow resistance, is influenced by the paper machine e.g. paper web and fabric flow resistances, pipe truncation losses, position of any control valve in the pipeline, etc. For example, the resistance curve of a new (clean and fluffy) blanket is a slightly rising curve. It is characterized by the fact that a small increase in the vacuum level increases the volume flow considerably. The resistance curve f2 of the old blanket (clogged and compressed) is steeper, whereby a small increase in vacuum level increases the flow rate only marginally.

Thus, in Fig. 1B, the graphs f, and f2 show said suction system resistances. Fig. 25 scales f, represents the resistance curve for the new permeable material, and f2 is the resistance curve for the old clogged material, such as felt. D1, D2, D3 are different speed curves. The figure illustrates the change in the yield point as the material ages with graph E1. To achieve the same flow rate, the pump speed must be increased.

• · · 30. · · ·. As the felt ages, the flow rate of the centrifugal vacuum pump decreases if it rotates. · · ·. the speed is kept constant as the flow resistance through the blanket increases. If the volume flow • · * •. to keep it constant or to increase it, to keep the pump 10 rotating speed j. This is exemplified by curve E1, whereby increasing the pump speed increases both the vacuum level and the volume flow. In this example, ♦ · ... P1462; Iloro et al.

12 106974 It is assumed that when a blanket becomes blocked, both a higher vacuum level and a higher volume flow are required to maintain the moisture ratio or web consistency of the blanket. In practice, the situation may also be such that merely increasing the negative pressure is sufficient to achieve a substantially constant dewatering, whereby increasing the pump revolution-5 maintains the flow rate constant. The output point of the pump 10 can be adjusted by the method of the invention during the life of the felt. Such adjustment can be made according to the invention on the basis of measurements (for example, the amount of water leaving the felt, the moisture of the web). The tissue resistance curve shown in Fig. 1B is measured by varying the rotational speed of the pump and measuring its output, i.e. the flow rate, at different rotational speeds. In practice, according to a preferred embodiment of the invention, the measurement is made on a new tissue to determine its properties, i.e. the resistance curve. By making similar measurements on tissues of different materials and / or different manufacturers, it is possible to compare different tissues. When measuring the resistance curve for an old and clogged blanket, this information can be used to inform pa-15 paddle operator personnel of the need to replace the blanket. In addition, it is possible to add blanket condition monitoring to the system, which will alert you if any unexpected changes occur in the condition of the blanket during its normal life.

20 If not all of the inlet targets (or all machines) have the aforementioned continuous measurement based adjustment method, then the preferred driving mode can be determined, for example, with one machine based on accurate measurements or other experience. It is essential that the vacuum pump's output point must be changed (i.e., increased vacuum level) using the felt. during work to optimize total drainage, most often to maximize, and * · 25 to extend the life of your felt.

Il · • · • · ♦ ♦ ♦ ·

Changing the yield point, preferably during felt refinement, as the felt ages, with an adjustable speed centrifugal vacuum pump can be accomplished, for example, as follows: • 1 · 1) A constant volume flow. · · ·. From the predetermined yield curve it is known which rotation speed. ·. the torque pair corresponds to the desired flow rate. By continuously measuring the pump *. the rotational speed and torque and, if necessary, changing the rotational speed, can maintain the desired flow rate.

• · «« * ... P1462; Horo et al.

• · 13 106974 2) Increasing the speed of rotation as a function of time is especially useful when no more accurate measuring equipment is available, such as a sensor for measuring moisture in the blanket, but it is plausible that the blanket clogging occurs linearly, with steadily increasing rotation speeds. Of course, the blanket clogging can also be non-linear with respect to time, so that the change in rotational speed is not to be constant throughout the lifetime of the blanket over a given period, but possible different changes can be pre-programmed in the control unit.

3) Increasing the vacuum level as a function of time is especially important in situations where no more accurate measuring equipment is available, such as a felt humidity sensor, but it has to be believed that the blanket clogging occurs linearly, ie a steadily raised vacuum level compensates for the blanket clogging. Of course, the changes to the vacuum level need not be constant throughout the lifetime of the felt over a given period of time, but any different changes can be pre-programmed in the control / central unit.

4) Optional ROI transition curve

By knowing the rotational speed-torque pair corresponding to each yield point, the pump can be programmed to follow the desired yield point shift curve. Shifting the curve from one production point to another as the tissue resistance-20 curve changes. Option 1) is a special case of this, where the displacement curve is a vertical line in the volumetric flow vacuum in the coordinate system. The transition point of the yield point can be linear, line, parabola, or broken line. In other words, the displacement curve may be a graph of a second order or higher order in the given volume flow negative pressure coefficient, v, dynamics.

'25 ··. ·. In other words, the optimum operating point displacement curve E is determined at a suction site, e.g., in a paper machine, by measuring the amount of water leaving and / or the web or the moisture of the tissue while adjusting the pump speed to achieve the optimal · 30 · f vastusfunktion the suction side changes the optimum operating points of the control. · «·, / the central processing unit 100 memory. By measuring as described above, the optimal- «·. ···. The offset point curve is scaled to different suction targets, for example, with a paper machine • # 35 * in accordance with the free flow area of the suction box and the speed of the fabric. , 4 IM 462; Horo et al.

• t 106974

Fig. 1C shows the construction and instrumentation of the pump 10. The rotationally adjustable suction pump 10 is, for example, structured as a central centrifugal vacuum pump, the main parts of which are an engine 11, an impeller 13 mounted on a motor shaft 12, a spiral housing 14 and a bearing 15. The speed mm. pump speed 10 and torque (or power).

Measurements of the pump 10 may be arranged, for example, in accordance with the aforementioned Figure 1C. the measurements are indicated in Figure 10 Pl suction negative pressure

Tl Measurement of inlet air temperature

Ml Suction Humidity Measurement EI (S) Pump Speed Measurement EI (X) Pump Torque Measurement 15

Fig. 2A shows an suction pump system according to the invention connected by way of example to a suction box of a paper machine. This suction pump system comprises a speed adjustable suction pump 10, preferably a high speed pump and most preferably a high speed centrifugal vacuum pump connected to suction channel 20 but 17, which suction channel is further connected to the water separator 18. The suction channel 18 further passing the mixture of water and gas through the suction passage 20 from the suction box 21 which is against the tissue H1 of the paper machine / board machine. In the water separator: · 'the mixture of water and gas is divided into a substantially anhydrous gas fraction and water, 25 of which the gas fraction is sucked through duct 17 to suction pump 10 and out of the system.

1 ♦ 1 A fabric such as H1 of a paper or board machine is used to suck a mixture of water and gas into the interior of the suction box 21 into the interior of the suction box 21, the molds 21a1, 21a2 ... through 30 gaps. The water is further conveyed under reduced pressure to the water separator 18 into its internal space 19, where the water is discharged through the outlet conduit 18a. Suction box 21 also uses ♦ · · ··· 1 to remove water from the mass web M over the felt. In this case, the pulp track «M is the tissue of a paper machine or board machine, such as against wire H1 and dewatering:: 1: occurs from the pulp track through wire H1 into the space inside the suction box 21 and further 106974 to the aforementioned water separator 18. with control valves not shown.

The system of Figure 2A comprises the measuring sensors 5 shown in the representation of Figure 1C, for which at least information on rotation speed and pump torque (or alternatively power) is required. The information provided by these sensors is fed into the memory of the pump control / control unit 100, which also stores the resistance curve f of the felt H1 shown in Fig. 2A, i.e. the resistance function when the felt is new and unused. Preferably, the resistance / curve f2 of the blocked felt is also stored in the memory of the control / central unit.

The resistance curve f1 is stored in the memory of the central unit 100 such that the pump has been run at different speeds and the achieved negative pressure associated with each speed between the pump suction side and the pumped gas volume associated with the vacuum in m3 / min. By means of the control / central unit 100 and the aforementioned dimension and unit memory information, the pump rotation speed 15 is further modified as determined by the control / central unit 100.

When running a paper machine / board machine according to another preferred embodiment of the invention, the rotational speed of the pump 10 and the vacuum level and flow rate achieved with it are continuously measured. According to the invention, the rotation speed can be increased as the flow rate decreases or vice versa, whereupon the pump receives control from the central unit 100 based on the measurement data and, for example, when the felt begins to clog the central unit increases the pump rotation speed. . The quality of the paper remains good because the amount of dewatering from the blanket is preferably kept substantially constant throughout the papermaking process.

• · • · 9

When measuring a new fabric of a paper machine / board machine such as felt H1 or fabric, the resistance curve f · of that function can also be measured during pump operation, e.g., when using a paper machine / board machine, where the resistance function is -_. * ··. In addition to the resistance provided by the felt, other resistors such as the mass path,. resistance caused by valves or other felt. It is essential that, when doing such a comparison, the comparison should also be performed on a blocked blanket H1, which in its connection comprises corresponding resistance components such as a mass path, valves. 35 in certain control positions, piping, etc. It is essential for the invention that in the system «· • ·» 1 P1462; Horo et al.

106974 monitors the condition of the tissue machine of the papermaking machine during its operation and, based on said monitoring, adjusts the speed of rotation of the pump 10 and / or performs a felt change based on said monitoring.

Figure 2B shows a preferred embodiment of the invention. In the embodiment of Figure 2B, the resistor functions f1 and f2 are measured and recorded in a paper / board machine run situation where the pulp track M is against the paper machine tissue H1.

Fig. 2C shows a suction pump system according to a preferred embodiment of the invention in connection with the filter material H2. The drawing schematically illustrates a suction drum filter 30 whose suction cups 10 are subjected to suction by the suction pump 10 provided under the tear or web surface H100. The procedure for controlling the pump 10 is similar to that of the embodiments shown in Figs 2A and 2B.

As shown in Fig. 2C, the suction pump 10 draws liquid through material H2, which is preferably from the filter material and the filter material is located on the other side of the filter material in state F. Also in this embodiment, the resistance curve of the filter material H2 20 can be measured first. The vacuum curve or material flow rate related to the resistance curve, i.e. material H2, and the pump speed rotation dependencies are driven into the memory of the CPU 100 and the corresponding data of the clogged filter. Also in this embodiment,. *. • where the pump, its speed, can be adjusted based on the operating point data obtained through measurements, and when a certain • unauthorized operating point is reached, the central unit gives an alarm to stop the pump and clean the filter when lifted or replaced. The permissible operating range of the pump is between the resistance curve f of the new material H2 and the resistance curve f2 of the clogged material H2. The material to be absorbed by the pump can be air, gas, liquid or a mixture thereof, and is always a gas-liquid mixture for filtration. Thus, in the most general embodiment of the invention, ···. The material absorbed by the pump is not restricted to air, for example.

• »· • * · • · • · *. As can be seen from the foregoing, the suction pump system according to the invention may be used »other than in the paper industry. For example, various vacuum filters are used to raise • «. 35 consistency of fiber pulp or slurry in many different industrial processes. Filters can • * • · • «· ... 1U 462; Horo et al.

«T * * 106974 may be of the drum or disk type. From the vacuum pump's point of view, such a process is comparable to the paper machine web + pulp web case. The purpose of the filter is to remove enough liquid from the pulp to achieve the desired solids content. The optimum driving mode is then to measure the dry matter content after the filter 5 and adjust the vacuum accordingly.

Figure 2D illustrates the use of a suction pump system according to the invention. Block diagram of the step a) is measured and stored in the pump 10 or the central control unit 100 in the memory 10 on the suction side of the pump ominaisvastusfunktio f, ie. Resistance curve at different pump speeds as suction occurs through new material introduced H1, H2. Thus, at a given speed, the achieved vacuum level at the suction side of the pump and the achieved flow rate corresponding to the vacuum level are stored, for example, in m3 / min. In step b), the resistivity curve f2 of the material H1, H2 clogged in the memory of the central unit 100 of the pump 10 is stored.

In step c), the CPU 100 microprocessor determines the operating ranges in general; the vacuum level and the corresponding flow rate at which the equipment is allowed to operate. In step d), the alarm limits, i.e. the value ranges, i.e. the operating ranges, in which the system and the pump should not operate, are determined, whereby the alarm can be used to change the tissue. If the resistance curve rises above f2, the rotation speed will no longer get out of it, but the only option is to replace or refurbish the tissue or filter surface or perforated surface of the paper or board machine.

During the operation of the suction pump system, the pump torque and pump speed are measured and, when the pump characteristic curve is stored in the memory of the pump's 10 * 25 control / central units, it can be computed by the pump's 100 microprocessor or external processor. • vacuum level corresponding to each torque and pump speed directly on the suction side of the pump and. the flow rate associated with that vacuum level. From the intersection of the pump torque curves and • · rotation speed curves, the vacuum level at the pump 10 operating points * 30 and the corresponding flow rate can be calculated.

* * * 9 · I «9 9 9. "\ This is how the current operating point of the pump can be compared with the permitted operating points and aa» •. performs alarms and / or pump control based on said operating point information and • · following comparison.

> m t • ·. 35 • »• ·

• M

P1462; Horoetal.

e »• · * 9

Claims (27)

An operating system for a suction pump used to draw liquid through a perforated or wire-shaped surface, the operating system comprising a suction pump (10) having a _. 25 speed control connected to a suction object and at least means for operating <<S "of the function of the suction pump (10), characterized in that also means for determining the operating location of the suction pump (10) and an operating / control unit (100) are included in the system. i • · [which control / central unit • · - the suction pump (10) curve cutter is stored, and • · · # · »# 30 - data for determining the suction pump (10) operating location are entered, whereby the ♦ ♦ resistance function (f, ) of the suction pump (10) is determined by changing the ··· rotational speed of the suction pump (10) and storing the suction pump operating points at different «· ··· rotational speeds in the control / central unit, which resistance function (f,) indicates a suction resistance which comprises at least one suction object located on the suction side (H1, 35 H2), from which or thereby medium, such as for example gas, liquid or a mixture thereof, is suctioned. P1462; 1 loro et a in. 24 106974 Operating system according to claim 1, characterized in that the second resistance function (f2) of the suction side of the pump is also stored in the memory of the central unit (100), which function indicates a suction resistance consisting of at least one suction object (H1, H2), the permeability of which has changed. in operation, ie the suction object is clogged. Operating system according to claim 2, characterized in that the pump operating location is operated such that the operating location is within an allowable operating range limited by said resistor functions (f, and f2) stored in the memory of the central unit (100), each resistive function (f ) indicates the vacuum on the suction side of the pump obtained at a determined rotational speed of the pump and the flow of medium (material volume / time unit) thus obtained from the suction object (H1, H2). Operating system according to claim 2, characterized in that the function (f,) stored in the memory of the central unit (100) refers to an unused, new suction object (H1, H2) and the function (f2) to an used suction object which requires maintenance. , repair, cleaning or replacement. Operating system according to claim 1, characterized in that the suction object (H1), from which or thereby the pump (10) sucks the medium, is a tissue at a paper or cardboard machine. Operating system according to claim 1, characterized in that the suction object (H2), from which the pump (10) sucks the medium, consists of a filter material, such as, for example, a perforated or viral surface drum in a drum filter or a drum filter. perforated or * ·· · viral surface in a filter sector of a disk filter. • · • · «: V: Operating system according to claim 1, characterized in that the suction side of the pump (10) is connected to a water separator (18), which water separator (18) is further connected to a suction drawer (21) or the like, over which The perforated or wire-shaped surface of the tissue (H1), the felt, the wire or the equivalent (H2) of the paper machine is adapted to run, and the method comprises measuring the vacuum level on the suction side of the pump (10), the speed of rotation of the pump (10) and the temperature of the medium. which is sucked with the pump (10) · • «35 • · •« .1 ··. OI462; Horo et ai. • «• 1 · 106974 Operating system according to claim 1, characterized in that the pump (10) is connected by a water separator (18) to a suction drawer (21) or the like, where the tissue, such as a felt or wire, is on the paper machine or the like against the suction drawer (21). surface, and that water is drawn through the surface of the tissue into the interior space of the suction dance (21) and thence further to the water separator (18), from which the water is withdrawn through an outlet (18a1). 9. Operating system according to claim 1, characterized in that the suction object consists of a tissue at a paper machine or equivalent and a pulp web thereon. 10. Operating system according to claim 1, characterized in that the suction object consists of a tissue at a paper machine or equivalent, a pulp web thereon and a tissue on the other side of the pulp web. Control system according to claim 1, characterized in that the suction object is a filter surface in a suction filter. 12. An operating system according to claim 1, characterized in that the suction object consists of a filter surface in a suction filter and a pulp web thereon. Control system according to claim 1, characterized in that the resistance function (f) of the suction side of the pump (10) is stored in the memory of the control / central unit (100) of the pump (10), which function relates to the filter material and the substance to be filtered. from which substance liquid is sucked, or that air or gas is sucked through. ' · The filter material, the filter acting as an air filter or a gas filter. ·: · 25 ···· Operating system according to claim 1, characterized in that the resistance function ·: **: (f) of the suction side of the pump (10), a.o. the air volume and vacuum level associated therewith: V: and the pump rotation speed associated therewith are stored in memory of: T: the pump / 10 operating / central unit (100), which has a resistance function as a suction resistor, in addition to the tissue at the paper machine; also the pulp web in conjunction with it, whereby the value pair is stored in the memory of the central unit (100) during m machine input, when the pulp web has been in contact with the tissue of the paper machine. • · A method of operating a suction pump (10) with speed control used to draw fluid through a perforated or wire-shaped surface, which pump is * 1 P1462; Horo et ai. · 26 106974 connected to a suction object (H1, H2), from which or thereby gas, liquid or a mixture thereof is sucked with the suction pump (10) and to which the pump is connected devices for actuating the pump function, characterized in that the pump (10) operating point is controlled with the control / control unit (100) relative to the curve cutter of the pump 5 (10) and the rotational speed data of the pump (10) or torque or power data, at least on one of which the suction object (H1, H2) induces a change, and that the pump (10) said operating point is controlled by changing the rotational speed of the pump (10). io 16. A method according to claim 15, characterized in that the resistance function (f1) of the suction side of the pump is stored in the memory of the control / central unit (100) of the pump (10), in which function the resistance is a suction object, i.e. eating at least one unused new material (H1, H2), whereby air or liquid is sucked, and also a resistance function (f2) is stored as comparison data in the memory of the central unit (100) of the pump (10) in which function a used, clogged material ( H1, H2), whose permeability has changed, has been used as a suction resistor through which material air, liquid or a mixture thereof is sucked, the data being clogged during use constituting comparison data, due to which the control / control unit (100) reports the maintenance or replacement needs of the material. 20 17. A method according to claim 15, characterized in that the operating point of the pump (10) is operated with the control / central unit (100) to follow some predetermined transition curve (E) in a coordinate system of volume flow vacuum by simultaneously changing the rotational speed of the pump (10). as suction side resistance function (f) in · ··· 25 is changed. • · · · • · i 4 4 · The method according to claim 17, characterized in that the transition curve (E) of the operating point is a constant volume flow curve, ie. a vertical coordinate system of • ·: * · *: volume flow vacuum. 30 • *** j 19. A method according to claim 17, characterized in that the transition curve (E) for the 4 4 4 operation site consists of a stretch or a break line running through two or more 4 4 4 | . determined points in the coordinate system on volume flow vacuum. • · 4 · ·, ··. PI462; Horo et ai. 106974 20. A method according to claim 17, characterized in that the transition curve (E) for the operating scaffold is a graphical representative of a function of the second or higher degree in the coordinate system on volume flow vacuum. 5 21. A method according to claim 17, characterized in that the transition curve (E) of the operating scaffold is determined in some suction object, for example in a paper machine, by measuring the decisive water volume and / or the moisture of the pulp or tissue and at the same time regulating the speed of rotation of the pump (10). to achieve an optimum output water volume / tissue moisture and by storing the optimum operating locations in the memory of the control / central unit (100) as the suction side resistance function (f) changes. 22. A method according to claim 21, characterized in that the optimum transition curve for the operating scaffold determined by measurement is scaled to different suction objects in a suitable ratio to the free flow surface of the suction cup (21) and the velocity of the tissue. 15 23. A method according to claim 15, characterized in that the suction object (H1, H2), whereby liquid or air is sucked, is constituted by a filter material, the resistance function (f relating to the material concerned, ie vacuum level on the suction side of the pump (10) as is achieved with a determined rotational speed of the pump (10) and the flow volume 20 (rrrYmin) associated therewith is stored in the memory of the control / central unit (100) of the pump (10). 24. A method according to claim 15, characterized in that the vacuum measured in relation to the pump (10) constitutes the difference in pressure which exceeds the pump (10). Method according to Claim 15, characterized in that several suction objects are connected to the same control / control unit at the paper machine, the moisture of the paper web is measured after the press section, before the drying portion and the dry content are maximized by regulating the vacuum in all the suction objects simultaneously. 30 : ***: 26. A method according to claim 25, characterized in that vacuum level in each suction object and the relationship of the vacuum between different suction objects is searched by an intelligent control system and unclear logic. · 4 I »• ·» · * · ·, · ·, P1462; Moro et al. • * 28 106974 A method of introducing an operating system into a pump, which operating system is intended to operate a pump (10) with speed control, and which system comprises at least devices for determining the rotational speed of the pump (10), devices for determining the power or torque of the pump, and an operating / control unit (100), in which memory the curve cutter of the pump (10) is stored, in which said definite data is input and with which the function of the pump (10) is operated, characterized in that the resistance function (f) of the pump (10) suction side is stored in the memory of the central unit (100) of the pump (10) in such a way that the pump (10) is provided with devices for measuring its volume flow, the suction side of the pump (10) is provided with devices for measuring the vacuum, and the pump (10) rotational speed and / or torque are determined with appropriate accuracy as a function of the pump flow (10) volume flow and / or suction side vacuum. IIIII «II • ···« · «· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · I | I I 1 a • <4 «· • · • t • 1« · • M .1 ·. Pl462; Horo et ai. • t »· i