scholarly journals OTOMATISASI KONTROL POMPA ULTRAFILTRASI DAN POMPA TEKANAN TINGGI REVERSE OSMOSIS PADA UNIT AIR SIAP MINUM MENGGUNAKAN SCHNEIDER ZELIO SMART RELAY

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Imam Setiadi ◽  
Irwan Kustianto

Kebutuhan air minum serta akses untuk mendapatkan air minum yang sehat menjadi kebutuhan dasar yang harus dipenuhi terutama di daerah-daerah yang rawan air. Terutama  daerah-daerah yang sulit dijangkau atau tidak  mendapat pelayanan air bersih yang disediakan oleh Perusahaan Daerah Air Minum dan lokasi yang secara geografis juga sulit untuk mendapatkan sumber air yang baik. Adanya sarana  penyediaan air bersih dengan sistem ultrafiltrasi dan reverse osmosis yang dikembangkan oleh Pusat Teknologi Lingkungan BPPT memungkinkan untuk diterapkan dilokasi-lokasi sulit mendapatkan air, sehingga masalah kesulitan air dapat teratasi. Hanya saja perlu pengelolaan yang baik, serta operator yang cakap, sehingga alat tersebut dapat beroperasi secara berkesinambungan. Kemudahan dalam mengoperasikan, serta otomatisasi menjadi pertimbangan tersendiri terhadap kemudahan dalam pengoperasian alat tersebut. Jenis pompa  dan peralatan pengontrol tangki-tangki dipilih  agar  masyarakat tidak sulit mencari suku cadangnya.  Untuk mengontrol tangki-tangki air pada sarana penyedia air bersih sistim ultrafiltrasi dan reverse osmosis digunakan teknologi yang sederhana, yaitu radar untuk mengatur tinggi muka air, pressure switch sebagai penunjuk tekanan air, serta PLC Schneider Zelio Smart Relay sebagai pusat kontrolnya. Sistem kontrol radar, pressure switch dan PLC schneider zelio smart relay berharga murah, mudah dalam penerapanya dan dijamin ketersediaan suku cadangnya.  

Author(s):  
W. C. Bigelow ◽  
F. B. Drogosz ◽  
S. Nitschke

High vacuum systems with oil diffusion pumps usually have a pressure switch to protect against Insufficient cooling water; however, If left unattended for long periods of time, failure of the mechanical fore pump can occur with equally serious results. The device shown schematically in Fig. 1 has been found to give effective protection against both these failures, yet it is inexpensive and relatively simple to build and operate.With this system, pressure in the fore pump line is measured by thermocouple vacuum gage TVG (CVC G.TC-004) whose output is monitored by meter relay MRy (Weston 1092 Sensitrol) which is set to close if the pressure rises above about 0.2 torr. This energizes control relay CRy (Potter & Brumfield KA5Y 120VAC SPDT) cutting off power to solenoid-operated fore line valve Vf (Cenco 94280-4 Norm. Closed) which closes to prevent further leakage of air into the diffusion pump


Author(s):  
H. K. Plummer ◽  
E. Eichen ◽  
C. D. Melvin

Much of the work reported in the literature on cellulose acetate reverse osmosis membranes has raised new and important questions with regard to the dense or “active” layer of these membranes. Several thickness values and structures have been attributed to the dense layer. To ensure the correct interpretation of the cellulose acetate structure thirteen different preparative techniques have been used in this investigation. These thirteen methods included various combinations of water substitution, freeze drying, freeze sectioning, fracturing, embedding, and microtomy techniques with both transmission and scanning electron microscope observations.It was observed that several factors can cause a distortion of the structure during sample preparation. The most obvious problem of water removal can cause swelling, shrinking, and folds. Improper removal of embedding materials, when used, can cause a loss of electron image contrast and, or structure which could hinder interpretation.


2019 ◽  
Vol 62 (5) ◽  
pp. 1326-1337 ◽  
Author(s):  
Brittany L. Perrine ◽  
Ronald C. Scherer ◽  
Jason A. Whitfield

Purpose Oral air pressure measurements during lip occlusion for /pVpV/ syllable strings are used to estimate subglottal pressure during the vowel. Accuracy of this method relies on smoothly produced syllable repetitions. The purpose of this study was to investigate the oral air pressure waveform during the /p/ lip occlusions and propose physiological explanations for nonflat shapes. Method Ten adult participants were trained to produce the “standard condition” and were instructed to produce nonstandard tasks. Results from 8 participants are included. The standard condition required participants to produce /pːiːpːiː.../ syllables smoothly at approximately 1.5 syllables/s. The nonstandard tasks included an air leak between the lips, faster syllable repetition rates, an initial voiced consonant, and 2-syllable word productions. Results Eleven oral air pressure waveform shapes were identified during the lip occlusions, and plausible physiological explanations for each shape are provided based on the tasks in which they occurred. Training the use of the standard condition, the initial voice consonant condition, and the 2-syllable word production increased the likelihood of rectangular oral air pressure waveform shapes. Increasing the rate beyond 1.5 syllables/s improved the probability of producing rectangular oral air pressure signal shapes in some participants. Conclusions Visual and verbal feedback improved the likelihood of producing rectangular oral air pressure signal shapes. The physiological explanations of variations in the oral air pressure waveform shape may provide direction to the clinician or researcher when providing feedback to increase the accuracy of estimating subglottal pressure from oral air pressure.


2014 ◽  
Vol 4 (2) ◽  
pp. 467-476
Author(s):  
Nisha Sharma ◽  
Jaspal Singh ◽  
Barjinder Kaur

Radionuclides (uranium, thorium, radium, radon gas etc.) are found naturally in air, water, soil and rock. Everyday, we ingest and inhale these radionuclides through the air we breathe and through food and water we take. Out of the internal exposure via ingestion of radionuclides, water contributes the major portion. The natural radioactivity of water is due to the activity transfer from bed rock and soils. In our surveys carried out in the past few years, we have observed high concentrations of uranium and total dissolved solids (TDS) in drinking waters of some southern parts of Punjab State exceeding the safe limits recommended by national and international agencies. The main drinking water source is the underground water procured from different depths. Due to the highly saline taste, disorders in their digestive systems and other ailments, people are installing reverse osmosis (RO) systems in their houses. Some RO systems have been installed on commercial basis. The state government is also in the process of installing community RO systems at the village level. As high values of uranium are also undesired and may pose health hazards due to radioactivity and toxicity of uranium, we have conducted a survey in the field to study the performance of various RO systems for removal of uranium and TDS. Water samples from about forty RO systems from Faridkot, Mansa, Bathinda and Amritsar districts of Punjab State were collected and analyzed. Our results show that some RO systems are able to remove more than 99% of uranium in the underground waters used for drinking purposes. TDS values are also reduced considerably to the desired levels. So RO systems can be used to avoid the risk of unduly health problems posed by high concentrations of uranium and TDS in drinking water.


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