T.T.K. Üzülmez Taşkömrü İşletme Müessesesinde havalandırma dirençlerinin ölçmelerle tesbiti

Abstract

Türkiye Taşkömürü Kurumu, Üzülmez Müessesesi 'nde gerçekleştirilen bu çalışmanın konusu, havalandırma kol dirençlerinin ölçmelerle tesbit edilmesidir. Havalandırma şebekelerinin planlanmasında, gerekli hava dağılışının sağlanmasında ve vantilatör tesislerinin tasarım ve seçiminde, ocaktaki havayollarının dirençleri büyük önem taşımaktadır. Bu nedenle dirençlerin doğru olarak tesbit edilmesi gerekmektedir. Bir havayolunun direnci, o yolun kesit alanı ve şekline, tahkimat türüne, uzunluğuna, ve yüzey pürüzlülüğüne bağlı olan sürtünme katsayısına göre değişmekte olup, her farklı havayolu için direnç değerleri de farklıdır. Bu çalışmada Üzülmez Müessesesi, Asma ve Dilaver İşletmesi Ocaklarında önceden yapılan gözlemlerle belirlenmiş olan değişik özeliklere sahip galerilerde, panolarda ve hava kapılarında direnç tesbiti için gerekli ölçmeler yapılmıştır. Bu ölçmeler sırasıyla: i- Hava miktarının CC£> hesaplanması için, kesit alanı CSD hava hızı CNO ölçmeleri, ii- Direncin CR3 hesaplanması için basınç farklarının Chl> Ölçülmesi, iii- Havanın rutubetinin ve yoğunluğunun tesbiti için, psikrometrik ölçmeler ve mutlak basınç ölçmeleridir. Ölçmelerde kesit alanları T. T. K Atölyelerinde yaptırılan plançete ile, hava hızları anemometre ile, basınç farkları eğik tüp manometre ile, mutlak basınçlar barolux ile, psikrometrik ölçmeler ise dönen psikrometr e ile yapılmıştır. Yapılan ölçmelerden elde edilen sonuçlarla ölçülen yolların dirençleri ve sürtünme katsayıları hesaplanmış tır. Elde edilen sonuçlardan üzülmez Müessesesi ocaklarındaki havayolları için, direnç ile kesit alanı arasındaki ilişki grafik olarak ifade edilmiştir. Ayrıca sür tünme katsayısı değerleri tablo halinde özetlenmiştir. Ayrıca ölçmelerle tesbit edilen sonuçların, literatürde verilen değerlerle mukayesesi yapılmıştır.

In the mining industry, inefficient ventilation has been the reason for production losses and many sudden disasters owing to explosion, fire and suffocation. Underground mining heath and safety regulations require a good control of the mine environment and this makes an efficient ventilation design more important. As the depth and mine area increase, ventilation design of mines becomes more complicated. The problems of mine ventilation are so different and sometimes very complex and difficult. To solve the problems, the good knowledge about the mine and mine ventilation networks must be carried out. A line dia gram must be prepared and necessary parameters for the calculation of mine ventilation networks are must be obtained by measurements in the mines. The aim of this study is to determine the friction factors and resistance of mine airways by measurements in Üzülmez District of North Western Coal Basin of Anatolia. This study has been carried out on July and August in 1990. The necessary measurements for determining the air way resistance and friction factor have been done. The estimation of the results and recommendations which should be aplied for the future works have been given in the thesis. The measurements, which have been carried out in this study to determine resistance are explained below: i- Measurements of airway crossectional area CS> and average air velocity CVO,for calculation of air quantity CQ> which flowing in the airway. viia The quantity of air CC£> flowing in an airway is not measured directly but is calculated from the aver age air velocity CVD and the crossectional area of the airway CSD at the point of measurement. Q = V x A, Cm3/secD Care should be taken in the measurement of the area particularly when the average velocity has been deter mined with satisfaction. The accuracy of the calculated air quantity COJ) depends on the accuracy of the measured average air velocity CVD and crossectional area CSD. Air quantity is the most frequently determined characteristic of the ventilation system. In spot checks, measurement of Q in key airways indicates sati: factory or unsatisfactory ventilation network. In precise surveys and all projections, knowledge or estimation of Q is one of two C along with head} quantative objectives in defining mine ventilation requirements. In this study, the average air velocity has been measured by using an anemometer. In the air velocity mesurements, the anemometer traversing method has been used. This is the routine procedure which is aplied when measuring air velocities in mine airways. While the anemometer is running, it is slowly and steadily moved up and down a series of imagined verti cal lines, so as to cover equal areas in equal time. The total period is usually one minute for a medium sized airway. Cfig.4.55 The crossectional area of airways have been measured by using a special instrument which have done in T. T. K workshops Cfig 4.23. This instrument consists essential y of two graduated wooden lath, of changeable length, which can be rotated through 180 in a vertical plane on a special table. This instrument has been set on the center of the airway bottom. The radial distance measurements have been made from the central point, and at observed angles CIO 3, and theese have been taken to the periphery of the airway. From the data so obtained, a scale diagram of the airway section has been prepared and the cr osssectional IX area has been read from this scale diagram by using a pi ani meter. Crosseciional area has also been calcula ted from formula. ii- Measurements of pressure differences between two points in airway to determine airway resistance CR3 from the following equation, which is called Atkinson formula: h = R. Q2,Ckg/ms2:> The measurement of pressure differences in airways has been done by using an inclined tube manometer. The manometer or "water gage" is a convenient instrument to use between points fairly close together. The manometer, as usually used, measures the dif ferences in head Cas a gage pressure!) along the static gradient between two points in the airway. A special liquid is used in the manometer to obtain greater sensivity, which has a specific gravity of 0.784 at 20 C and dyed deep orange-red giving an extremely clear and free moving meniscus. Cfig 4. 8D In measuring the pressure difference between two points in an airway, two rubber tube C inner diameter 10 mırû has been laid from the manometer 50 m distance away, then the manometer has been read. Cfig. 4. 93 iii- Psycr ometr i c measurements for determining the air humi di ty To determine the air humidity, a rotating psycro- meter has been used in the measurements. Dry bulb and wet bulb temperatures of air has been measured with psycr ometer and air humidity has been obtained from psycr ometr i k tables and psycr ometr i c charts which is given in some references. iv- Measurements of absolute pressure in the airway The absolute pressures have been measured with a barolux, which is a developed aneroid barometer. According to the results of measurements, which explained above, the airway resistance CRD has been calculated. After the calculation of resistance, the friction factor of airway has been calculated from the Atkinson formula below : h = R.Q2, Ckg/m. s2} LP 7 R = a. -'. Ckg/m D 3 where; L is the length of airway, P is the perimeter of the airway cross section, S is the crossectional area of airway and oc is the friction factor of the air way. Resistance values indicate the condition of the mine airways and for the purposes of comparison it is conve nient to use an index, the calculated resistance for a standart length, which is taken 100 m. Certain factors influence the values of resistance. This factors are : size of airway, airway lining, air way shape and air density The air density have not been measured directly but calculated from temperature and absolute pressure measure ments. The dry bulb temperature of air CtdD, which has been obtained from psycrometric measurements and absolute pressure CP>, have been used in the below formula and the air density have been calculated. Y = 0.462, Ckg/m3D C273+tdJ> The aim of air density determination is to search the effect of air density on airway resistance. Al tough pressure drop and airway resistance varies as the density of the air, in the majority of cases density changes have been negligible, and in the resistance calculations this changes have been ignored. XI Results have been obtained from the measurements of determining the airway resistance, which have been carried out in Asma and Dil aver Collieries in Üzülmez District as follows: 1- The friction factors of airways which have different support type and lining in Üzülmez District Collieries has been given as a table. Ctable 6. 2D 2- Determined resistances values for different cross sectional area and different airway support and lining has been given as resistance-area curve. 3- A comparison is done between the resistance values which are obtained from measurements, and the values of resistance which had been given in some references. It can be seen that, both resistance values, which are obtained from measurements and taken from references are close to each other for the same crossecti onal areas.