Sewage treatment process
The pretreatment of high concentration of chromium containing wastewater separate collection, alkaline precipitation recycling; The waste water with high sulphur content will be separate collection,
Catalytic oxidation desulphurization process. Comprehensive control of other tanning wastewater (including sewage) after pretreatment by comprehensive pipeline to bio – chemical secondary treatment in wastewater treatment plant. Primary processing integrated wastewater by fine grille, aerated grit chamber, adjusting pool and pool, balance water, remove large particles inorganic, part of the COD and BOD. Secondary treatment namely, biological treatment, the traditional activated sludge process, the piston flow reactor, drum wind aeration at this stage maximum degradation of pollutants in wastewater and removal.
Chemical processing the sewage into the pool chemicals for chemical coagulation precipitation, coagulant using basic aluminium chloride, inclined tube sedimentation. SS and COD in wastewater has been further reduced. Sludge treatment sink at the beginning of the sewage treatment process of sludge, sludge and chemical sludge concentration pool, after gravity concentration, sludge conditioning, enter the plate and frame filter press filter dewatering, returned to the sewage treatment system, the filtrate cake sinotrans central treatment by the local environmental protection department.
The processing of main monomer
2.1 pretreatment
2.1.1 sulfur-containing wastewater oxidation desulfurization
Special pipe separate collection, coarse and fine chrome bar two filtering; Manganese sulfate catalyst, additive concentration, 40-80 – g/kgNa2S before aeration and aeration respectively 2 hours after dosing twice; Table of forced oxygen filling machine, 20 mm impeller submersion depth, lead acetate dipstick test desulphurization effect, sulfide removal rate 95% or higher; Will try tanning ammonium deliming softening in sulfur-containing wastewater, in the process of oxidation desulfurization, have a function in addition to ammonia, NH3 – N removal rate is about 30%; Remove bottom mud regularly, ensure the treatment effect.
2.1.2 precipitation of chromium-containing waste water recycling
Special pipe separate collection, grille, double filter cloth filter; Adding 35% sodium hydroxide, controlling reaction pH7-8, compressed air mixed stirring, continuous reaction 15 to 30 minutes; Plate and frame filter, chromium mud solids content about 20%, 7-20% chromium content; Chromium removal rate > 99.5%.
2.2 the primary processing
Rotating the large particle of solid fine screen intercept wastewater, hair, skin, rotten meat, etc; Aerated grit chamber perforated tube evenly aeration and settling to remove sewage medium sand and gravel small particulate matter; Adjust pool aeration stirring for 24 hours, balance water, according to the average daily water to determine the adjusting pool for water level lower limit, according to the liquid level height adjust volume, qing pool regularly, dredge air perforated pipe, guarantee the air flow; Advection pond, at the beginning of mechanical scraping mud, mud gravity centrifugal pump mechanical dredge, according to the daily sewage quantity determine the pond, water flow, according to the nature of carbon sludge such as thickness, smell and so on to determine the number of mud and time;
Primary treatment effect

Keywords analyzer sample processing system technology process analysis system for the sample parts

1 the status of sample gas handling system in the process of analysis system

Sample processing system if only process gas analysis systems, it is called the sample gas handling system.

Engineering technology in the industry in the process of analysis, sample gas handling system described in this article, the past has been called sampling pretreatment system, the pretreatment system, the gas sample pretreatment system, the sampling and pre-processing units, etc. Due to long with a word “advance”, as if just additional part of the process analyzer, did not receive the attention they deserve.

GB/T 19768-2005 “said analyser sample processing system in the process of” the national standard, actually to standard JB/T 6854-1993: machinery, already cancelled before processing system “forecast”, it is bound to lead; Sample gas handling system and technology concepts and terminology of sample gas handling parts. Unfortunately, for a long time did not get people attention and recognition in the industry.

This article emphatically elaborated the sample gas handling system of technology, has its relative independence, rigor, systemic, control function and software of PLC programmable controller is a proof. Germany H&B company 60 s type dry temperature sampling probe alone there are as many as dozens of sets of sales in the Chinese market, the highest price 1.35 million yuan, is a persuasive proof.

In order to promote the development of process analysis system for engineering application technology, we should have a kind of new technology concept: the process analysis to face many tough complex technical problem, the sample gas handling system is the core and key technology of process analysis system, looking forward to the sample gas handling system from now on to improve and development.

2 process analyzer engineering application technology of sample gas handling system dependent and requirements

2.1 1986 years ago, the domestic various analytical instruments process of advanced analytical instruments are on the market in the form of single machine sales, almost all the German H&B company process analyzer has about two-thirds (including analysis cabin) based on process analysis system on the market, in the form of sample gas handling system at that time there was a “pre” word is not case.

Three technologies such as sic infrared introduction as an opportunity, at the same time from H&B company introduced technology process analysis system, and two training system design and engineering application talent, make the sic inadvertently acted as a pioneer engineering application process analyzer, the role of the design level, application level and the scale of production has a great progress.

2.2 process analyzer the sticking point of engineering application and the best way

Long-term continuous process analyzer, timely detection, strictly necessary for continuous sampling and of sample gas handling technique, require sample gas and transport fast, real sample gas into the analyzer, gas demand reach to standard of quality. Long-term continuous operation process analysis system reliability and security, and easy maintainability, almost no maintenance is fully rely on the pertinence design of sample gas handling system technology.

According to every process analysis system for field application condition and the sampling condition, to adopt specialization, standardization, the specific design of special process analysis system, produced by professional manufacturers with long-term engineering practice experience the process of high quality analysis system, and take the whole process of technical services.

For process gas analysis, is to make the sample gas handling system and decisive technology with different application conditions and the environment conditions match properly, and perfect combination. Process analyzer the absolute dependence of sample gas handling system, making the process analyzer analysis to fill the order form process analysis system is a process engineering technology development, and it’s been in the industry.

This article from the Fabrication Services Suppliers

TLC5941 driver chips

TLC5941 chip is the latest TI Texas instruments) company, has high point correction, grey scale (PWM) control, etc. TLC5941 all internal data register, gray register, register point calibration and error status information through the serial interface to access to the largest serial clock frequency of 30 MHZ, generally within plus or minus 6%, between the current error between the current error generally within plus or minus 4%, per channel maximum output current 80 ma

TLC5941 each channel available PWM mode according to the internal gray register values for level 4096 gray scale control, the register is 12, each channel LED driver circuit from 6 loci correction control register values for level 64, and the maximum of the drive current can be set off chip resistor. Current control provides a level 64 LED point gray level correction ability, level 4096 gray-scale adjustment is to ensure the even under the low grey scale, each point in the lattice has as many as 256 level gray scale, said to all red, green and blue color can be 16 m color color expression ability, both for high quality color large screen display is especially important compared with traditional color large screen display system, concentration to produce PWM gray-scale control, programmable logic chip (or high speed CPU cache management, gray level correction and point data need to deal with the output, reduce the design complexity, and the PWM gray-scale control has nothing to do with data serial removed, can easily get high frame frequency, obtain good dynamic display effect.

In order to ensure the reliable operation of large color screen, TLC5941 provides each LED all the way open circuit (LOD and temperature detection (TSD ability, the built-in open collector output circuit, is used when something goes wrong alarm. Whichever channel has 16 channel error occurs, the built-in open collector output circuit of the output pin is pulled to the low level, by querying the chip’s internal state information, you will know that which way fails, all the TLC5941 built-in open collector output circuit in the system output pin can be together, through the pull-up resistor receives high level, by monitoring the signal, the system can be in operation in the process of self diagnosis. Meanwhile TLC5941 is suitable for the working environment is poor, the display effect is very demanding and high performance requirements on safety, such as highway LED message sign, large outdoor LED TV, etc.

MBI5028 driver chips

MBI5028 Taiwan MBI macroblock) launched a programmable current gain function of LED driver chips. Built-in string and shift register and the output latch, and adopt PrecisionDr technology to get more superior electrical properties. MBl5028 serial clock frequency is 25 MHZ, largest piece between the current error within the plus or minus 6%, generally between the current error generally within plus or minus 3%, maximum output current is 90 ma

MBI5028 built-in current gain control logic unit and a programmable current gain function of the Share – IO technology, do not need to add additional tube feet, only need to the corresponding pin input a specific sequence of signals, it can be adjusted into MBI5028 special function mode – the current model. In this mode, it can be through the system microcontroller, to write different current gain control logic unit current gain data, lock to save these data, and through the built-in digital to analog converter of sharing, to effectively control the current output. Aging due to the change of working environment and the LED screen, LED brightness will be reduced, such as at a fixed forward current, the brightness of the LED screen deviation will be smaller. Through programmable current gain PrecisionDr technology and function, can adjust the current deviation, compensate for the brightness of the LED screen, get a high quality images at the same time. PrecisionDr technology is used and Shared built-in digital to analog converter, under the same precision, by changing the way of digital code to gain relative to the output current, thus improving image quality of the LED screen.

Current technology can provide the LED display screen with current level, 256 to 1200% of the total dynamic range, provide 256 output current rating. Electrical characteristics and chip packaging, MBI5026 compatibility is better, users don’t have to change for the PCB of the same kind of chip design before, can get a Share – IO technology of current gain technology, can greatly reduce the cost of upgrade. MBI5026 is suitable for the work environment conditions are not demanding, but requires high quality LED driver solution on imaging, such as indoor large LED display and other mid-range screen. MBI5028 also applies to the upgrading of old driver chip.

ST2221C driver chips

ST2221C Taiwan SITI point crystal science and technology) company of China able to launch a LED drive chip. The built-in string and shift register unit, the output latch unit and control unit, the output current is relatively good electrical characteristics. ST2221C serial clock frequency is 25 MHZ, largest piece between the current error within the plus or minus 10%, generally between the current error generally within plus or minus 6%, maximum output current is 120 ma ST2221C contains a 16-channel constant current drive unit, can also drive a 16-way LED applicable to drive some low-end screen, such as indoor LED display information screen and so on the low end.

There is a problem

Power consumption and heat problem

Because of its high output current, power consumption and fever of LED display chip is the first factor of blocking driver chip development. Hand-held LED display that may occur in the future on the drive way, the problem would be particularly. With the progress of LED device manufacturing technology level and the decrease of the drive current, the problem will be solved step by step.

Application cost problem

A 16-bit steady-state current mainstream LED display drive chip can only drive a 16-way LED device. A resolution of 1024 x 768 led display must be used more than driving chip to achieve the desired effect, which makes the cost of materials is quite high. If the driver chip itself USES the scanning mode, a mainstream drive chip can drive multiplexed LED device at a time, will make the cost down many application.

The Trade Directory summary

From the terms of the structure of several LED drive chip manufacturers products, is currently the mainstream chip is mainly divided into three grades. The first class is a chip with gray mechanism, this kind of IC with PWM function, can according to the input data to produce gray, are more likely to form deep gray, display high quality images. Second class is to have the output open circuit detection (LOD temperature overheating protection (TSD brightness adjustment function of the chip, the chip with the additional features and more suitable for specific occasions, such as used for the variable information board, to have the function of the detection error LED chip. Third is without any additional features constant current source chip, this chip is only provided for the LED constant current source, ensure the quality of screen display is good.

A, circuit component

When need to use more LED products, if all the leds in series, will need the LED driver output high voltage: if all the leds in parallel, you need the LED driver output larger electric current. All the leds in series or in parallel, not only limits the strict use of LED, and parallel LED load current is bigger, drive cost will increase, the solution is to use the hybrid mode. Average distribution of the number of leds in series, in parallel, so that allocation on an LED series branch voltage is the same, the same series branch current is basically the same on each of the leds, the brightness is consistent, also close by each series branch of current.

Second, the circuit performance analysis

When a series branch have a LED on the poor quality and short circuit, whether driven by voltage type way or constant current drive mode, through the series circuit current will increase, it is easy to damage the leds in series branch. Large current through the damaged after this string of leds, as a result of the through current is bigger, more performance for open circuit. Disconnect after a LED series branch, if the voltage type drive mode, drive the output current will be reduced, without affecting the rest of the all the LED to normal work.

If using constant current LED driver, due to the output current is kept constant drive, allocation will be increased in the rest of the LED current, easy to damage all the leds. Parallel LED solution is as much as possible, so that when disconnect only one LED, distribution in the rest of the LED current is not large, not affect the rest of the LED to normal work.

This series after parallel lines first line of the method is simple, stable, brightness, high reliability, and low consistency requirements for devices, do not need to specially selected device, even if an individual LED single pipe failure, affect the luminous component is lesser also. In the case of larger changes work environment factors, use the connection form of luminous element relatively ideal effect.

Hybrid mode there is another type of connection, that is, LED will be evenly after the grouping in parallel, then each group together. When there is a poor quality and short circuit, LED both driven by voltage type mode and constant current drive mode, all parallel in this branch of the leds will not bright. If using constant current LED driver, due to drive the output current is kept constant, except in parallel on the short circuit of LED a parallel branch, the rest of the leds are working properly. Assumptions of the large number of leds in parallel, drives drive current is bigger, through the short circuit of the LED current will only grow. After the big electric current through the short circuit of the LED, it is easy to become open circuit. Due to parallel LED more, disconnect after a LED, the average distribution of current change is not big, the rest of the leds can still work normally, so in the whole LED lights there is only one LED is not bright.

Luminous element consisting of before and after the series of mixed connection problems, mainly in the field of a single set of parallel LED because of the difference between the device and the conditions of use, single LED chip could lose in a single set of p-n junction characteristics, short circuit. Individual device short-circuit failure LED to lose their jobs have not yet been current IF the LED goes out, “‘” ’cause the whole through from the short circuit devices, full of the total current and a long time to the short circuit current will make the device internal bonding wire or other parts of the burned, open circuit. At this time, not the failure LED to current, normal light, just working current IF bigger than the original. This is the first luminous element appears in the form of a set of the connection of several LED goes out together, after a period of time in addition to the one of the LED not bright, other reasons LED back to normal again.

Three, the choice of drive

Through the above analysis shows that the collocation of drive and load the LED series/parallel way choice is very important, in constant current drive power type LED, not suitable for the parallel load: similarly, voltage regulator series load type LED driver is not suitable for selection.

High voltage LED can sharply reduce the AC – DC conversion efficiency losses. 10 w output power, for example, if the forward voltage drop of 50 v, 1 w LED, high output side can take 2 and 4 string configuration, four leds in series of positive pressure drop to 200 v, that is to say from 220 v alternating current (AC) electric bridge rectifier and drop 20 v. But if we use the forward voltage drop to 3 v low voltage LED 1 w, even 10 together positive pressure drop 30 v, however, that is to say need to from 220 vac mains step-down to 30 VDC. As we know, the lower the input and output differential pressure, AC to DC conversion efficiency is higher, can be seen as using high pressure LED, transformer efficiency can be greatly improved, which can greatly reduce the power loss of AC – DC switch, the heat consumption reduce and can further reduce the cost of cooling shells.

So if use high pressure to develop LED general lighting products, LED the overall power consumption can be greatly reduced, so as to greatly reduce the heat dissipation shell design requirements, such as we can to be thinner and lighter aluminum shell can meet the demand of LED lamps and lanterns, heat dissipation, due to the heat dissipation aluminum shell cost is one of the major cost components of LED lighting lamps and lanterns, aluminum shell effectively reduce cost also means that the overall LED lighting lamps and lanterns is effectively reduce the cost. Thus, LED high-pressure can bring costs and effectively reduce the weight of the LED lighting lamps and lanterns, but the more important is lowered to the cooling system design requirements, thus effectively cleared the LED lighting lamps and lanterns enters the indoor lighting market the biggest technical barrier. As a result, the high voltage LED general lighting market will dominate the future of the LED.

(this paper turn from suppilers)