JPS62152555A - Centrifugal concentrator - Google Patents

Abstract

PURPOSE:To always obtain a concentrate with constant concn. and to also adjust the concn. of a separated liquid to an objective value or less, by providing a screw decanter type centrifugal concentrator controlling the concn. of the concentrate according to an inner body torque constant control system and an attachment detecting the concn of the separated liquid to control the supply amount of a raw liquid. CONSTITUTION:A process controller 5 is compares feedback signal of the torque value of an inner body 2 detected by a torque detector 13 and inputted through a torque display operator 14 with the set torque value of the inner body 2 imparted through a torque setting device 16 to calculate deviation. If there is deviation, the speed of a variable speed back-drive apparatus 17 is corrected through a first controller 18 so as to eliminate deviation to adjust the torque value of the inner body 2 to the aforementioned set torque value, the measuring concn. signal from a separated liquid densitometer 22 is inputted to an operator 24 and, when the concn. of a separated liquid exceeding an objective value was detected, a second controller 25 inputs a signal exceeding said objective value to reduce the supply amount of a raw liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a centrifugal concentrator, and more specifically, a screw decanter type centrifugal concentrator is used to treat sewage, human waste,
The present invention relates to an apparatus for concentrating a liquid to be treated such as industrial waste liquid.

Conventional technology in general! The condenser is often used to pre-treat waste for the next step, and therefore it is often necessary to keep the concentration of the concentrate constant.

As an example of a means for keeping the concentration of the concentrated liquid constant in this kind of conventional centrifugal concentrator, there is one example of the method disclosed in Japanese Patent Application Laid-open No. 1986-
As described in Japanese Patent No. 40452, it is known to directly detect the properties (viscosity) of a concentrated liquid and to maintain the concentration constant by changing the mechanical conditions of a centrifugal concentrator. As another example, as described in Japanese Patent Application Laid-Open No. 58-205554, a feed liquid, a clarified liquid (separated liquid),
It is known to detect each liquid volume of the concentrated liquid, the concentration of the supply liquid, and the concentration of the clarified liquid, and calculate each of them to make the concentration of the concentrated liquid constant.

Problems to be Solved by the Invention In one example of the conventional technology mentioned above, the concentration of the concentrated liquid is measured from the viscosity of the concentrated liquid, which is affected by the shape of the concentration tank, the temperature environment, etc., and it is difficult to obtain highly accurate values. Moreover, since the followability is unfavorable, intermittent control is required, a new viscosity measuring device is required, and the clarity of the separated liquid cannot be controlled. In addition, in another example of the conventional technology mentioned above, there are many measuring instruments, which are expensive and complicated, and the followability is not desirable.
There is a problem that the control is intermittent and the clarity of one separated liquid cannot be controlled.

The present invention attempts to solve these problems. That is, the present invention does not require special instruments such as a concentration meter or a viscometer, and it is possible to reliably obtain a concentrated liquid having a stable constant concentration regardless of changes in the properties of the stock liquid. It is an object of the present invention to provide a centrifugal concentrator that can simultaneously reduce the concentration of the concentrated liquid and the separated liquid to a target value or less.

As a solution to the problem, we installed a screw decanter-type centrifugal concentrator that uses a constant internal torque control system to control the concentration of concentrated liquid, as well as an attached device that detects the concentration of separated liquid and controls the amount of raw liquid supplied. That is, the configuration of the present invention includes a torque detector that continuously detects the torque value of the inner barrel of a screw decanter type centrifugal concentrator.

a process regulator that inputs the torque value detected by the torque detector as a feedback signal via a torque calculator; a torque setting device that provides a set torque value to the process regulator; and a first controller that inputs a deviation correction signal obtained by comparing and calculating the set torque value and corrects the speed of the variable speed back drive device so that the deviation is eliminated, and A separated liquid concentration meter that measures the concentration of the concentrated liquid and the separated liquid separated by the concentrator, a calculator that inputs the measured concentration signal from this separated liquid concentration meter, and a calculator that measures the concentration of the separated liquid that exceeds the target value. The present invention is characterized by comprising a second controller that inputs a signal from the computing unit to reduce the supply amount of the stock solution when the detection is detected.

Function In the screw decanter type centrifugal concentrator, since there is a correlation between the torque value of the inner shell and the concentration of the concentrate, the torque value of the inner shell is continuously detected by a torque detector. The detected torque value is then input as a feedback signal to the process controller via the torque calculator. A torque value of the inner barrel corresponding to a target concentrate concentration is provided as a set torque value to the process regulator via a torque setting device. The process regulator compares the feedback signal with the set torque value to determine a deviation. If there is a deviation, the speed of the variable speed back drive device is corrected via the first controller so that the deviation is eliminated, and the differential speed between the outer cylinder and the inner cylinder is automatically adjusted to adjust the torque value of the inner cylinder. to the set torque value. By controlling in this way, the concentration of the concentrated liquid can be kept at a constant target value. On the other hand, during this operation, the concentration of the separated class is continuously measured by the separated liquid concentration meter, and the measured concentration signal from the separated liquid concentration meter is inputted to the calculating unit, and the calculated concentration is calculated as follows: second when degree is detected.
The controller receives a signal that the target value has been exceeded and reduces the feed rate of the stock solution to keep the concentration of the separated liquid within the target value.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawings illustrate one embodiment of the invention. In the figure, 1
1 is a screw decanter type centrifugal concentrator, 2 is an inner barrel, 3 is an inner barrel screw, 4 is an inner barrel supply chamber, 5 is an outer barrel bowl, 6 is a feed pipe for supplying the stock solution, and 7 is a rotating part of the concentrator 1. The driving main electric motor, 8 and 9 are bearings, 10 is an arrow indicating discharge of concentrated liquid, 11 is an arrow indicating discharge of separated liquid, 12 is a reduction gear having a gear group, 13 is a torque detector, 14 is a torque display 15 is a process regulator, 16 is a torque setting device, 17 is a variable speed bank drive device, 18 is a first
Controller, 19 is the stock solution supply pump, 20 is the stock solution supply pump, and 20 is the stock solution supply pump. L concentration meter, 21 is a stock solution flow meter, 22 is a separated solution concentration meter, 23 is a separated solution flow meter, 24 is a computing unit, 25 is a second controller, 26 is a stock solution supply device, and 27 is a concentration display.

That is, as is well known, in a screw decanter type centrifugal concentrator, the raw solution containing solids, which is the liquid to be treated, is
The raw solution is supplied from the stock solution supply device 26 to the inner shell supply chamber 4 via a feed vibro.

Outer bowl 5 is guided into outer bowl 5 from an inner barrel discharge hole (not shown) and is rotated at high speed by a main motor.
The clarified separated liquid and the concentrated liquid are separated by the action of the inner cylinder screw 3, and the concentrated liquid moves in the outer cylinder bowl by the inner cylinder screw 6 (moves to the left in the figure), as shown by the arrow 10. It is discharged outside the machine from one casing outlet.

Further, the separated liquid moves to the opposite side of the concentrated liquid (moves to the right in the figure) and is discharged from the other casing outlet as shown by arrow 11.

In the present invention, during such operation, the torque value of the inner shell 2 is continuously detected by the torque detector 13 via the reducer 12, and is sent as a feedback signal to the process regulator 15 via the torque display calculator 14. input. On the other hand, the optimum performance torque value is determined in advance according to the characteristics of the screw decanter type centrifugal concentrator 1 and attached equipment used and the processing conditions of the stock solution, that is, the inner barrel screw 3 is adjusted to achieve the target concentration of the concentrated solution. The optimum scraping torque value is given to the process regulator 15 from the torque setting device 16 as a set torque value. Then, the process regulator 15 compares the set torque value with the feedback signal, calculates the deviation using a known ratio f9+1 integral method, and issues the result to the first controller 18. Here, when the feedback signal, that is, the deviation of the scraping torque value of the inner barrel screw 5 detected during operation is found to be small with respect to the set torque value, the process controller 15 The first controller 18 gives a signal to the variable speed backdrive device 17 to increase the speed of the variable speed backdrive device 17 so that the concentrator 1 can operate with the minimum difference. The differential speed is made small until the speed is reached, and the scraping torque value of the inner barrel screw 5 is made to become the set torque value. On the other hand, if a deviation is found from the set torque value such that the scraping torque value of the inner barrel screw 6 detected during operation is large, a signal opposite to the above is given and the variable speed bank drive The speed of the device 17 is decreased to increase the differential speed so that the scraping torque value of the inner barrel screw 3 becomes the set torque value. By doing this, the inner cylinder torque of the screw decanter type centrifugal concentrator 1 is controlled to be constant, that is, the concentrated liquid is controlled to be constant at a degree.

Generally, the differential speed ΔN is expressed by the following equation.

However, N is the rotational speed of the outer bowl 5, N2 is the pinion rotational speed of the reducer 12, N3 is the rotational speed of the variable speed back drive device 17, α is the pack drive pulley ratio, and R is the reduction ratio of the reducer 12. It is.

In addition, in the figure, the torque detector 13 is installed on the reducer 12 side, but this is the variable speed back drive device 171pjl.
It may be installed in

Next, for the raw solution fl'ill K, a raw solution concentration meter (turbidity meter) 20, a raw solution flow meter 21, etc. are provided, and on the separated liquid side, a separated liquid concentration meter (turbidity meter) 22 and a separated liquid concentration meter (turbidity meter) 22 are provided. Flow meter 23
In addition, an arithmetic unit 24 and a second controller 25 for inputting signals from these measuring instruments are provided, and the above-mentioned scraping torque value constant control of the inner barrel screw 3 is provided. The concentration (clarity) of the separated liquid is also continuously measured during operation of the screw decanter type centrifugal concentrator 1, and when the concentration of the separated liquid exceeds the target value, the calculator 24 detects it. However, in order to reduce the supply amount of the stock solution, the second controller 25 controls the stock solution supply device 26 so as to always obtain the separated solution (clear o,) having the concentration of the target value.

Further, the concentration of the concentrated liquid whose inner cylinder torque value is controlled to be constant is calculated by the following equation and displayed as an actual concentration value.

However, α: concentration of the stock solution α2: concentration of the separated solution α3: concentration of the concentrated solution Ql: flow rate of the stock solution Q2: flow rate of the separated solution In this way, the concentration of the concentrated solution can be calculated without directly measuring the concentration of the concentrated solution. The concentration (clarity) of the separation liquid (clarified liquid) and the separation liquid (clarified liquid) can be controlled simultaneously and continuously.

Effects of the Invention The present invention includes a torque detector that continuously detects the torque value of the inner barrel of a screw decanter type centrifugal concentrator, and a torque calculator that uses the torque value detected by the torque detector as a feedback signal. A process regulator to input, a torque setter that gives a set torque value to this process regulator, and a deviation correction signal obtained by comparing and calculating the feed bank signal and the set torque value in the process regulator. Since it is equipped with a first controller that inputs input and corrects the speed of the variable speed backdrive device so as to eliminate the deviation, the concentration of the concentrated liquid can be continuously controlled to be constant by the torque value of the inner barrel. can. Therefore, there is no need for expensive instruments that directly measure properties such as the concentration or viscosity of the concentrated liquid, and control with high followability and degree of fiv is possible. In addition, there is also a separated liquid concentration meter that measures the concentration of the concentrated liquid and the separated liquid separated by the centrifugal concentrator, a calculation unit that inputs the measured concentration signal from this separation liquid concentration meter, and a separation liquid that exceeds the target value by this calculation unit. Since it is equipped with a second controller that inputs a signal from the computing unit to reduce the supply amount of the stock solution when the liquid concentration is detected, it is possible to control the amount of liquid for one separated liquid during operation under constant inner torque value control. can also be continuously controlled so that the target clarity can always be maintained.

[Brief explanation of drawings]

The figure is an explanatory diagram showing one embodiment of the present invention. 1... Screw decanter type centrifugal concentrator, 2... Inner barrel, 3... Inner barrel screw, 5... Outer barrel bowl, 1
5...torque detector, 14...torque display calculator,
15. ... Process regulator, 16... Torque setting device,
17°...Variable speed back drive device, 18...1st
Controller, 22...Separated liquid concentration meter, 24..., Arithmetic unit,
25... Second controller, 26... Stock solution supply device.

Claims (1)

[Claims] 1. A torque detector that continuously detects the torque value of the inner shell of the screw decanter type centrifugal concentrator, and a process regulator that inputs the torque value detected by the torque detector as a feedback signal via a torque calculator. Then, a torque setting device that gives a set torque value to this process regulator is inputted, and a correction signal for the deviation obtained by comparing and calculating the feedback signal and the set torque value in the process regulator is inputted, and the deviation is corrected. a first controller for adjusting the speed of the variable speed backdrive device so that the concentration of the concentrated liquid is reduced, and a separated liquid concentration meter for measuring the concentration of the separated liquid separated from the concentrated liquid in the centrifugal concentrator; a computing unit that inputs the measured concentration signal from the meter, and a second control that inputs the signal from the computing unit and reduces the supply amount of the stock solution when this computing unit detects a concentration of the separated liquid that exceeds the target value. A centrifugal concentration device characterized by comprising a container.