Coolant Spray Research Articles

Integrating 3D Printed Grinding Tools and Closed‐Loop Temperature Management for Optimal Surgical Outcomes

AbstractGrinding is a commonly employed surgical technique for the partial removal of bone. However, the grinding process often generates excessive heat at the interface, leading to localized temperature raise. This can result in irreversible damage to not only the bone but also surrounding tissues, such as nerves. Existing devices rely on the continuous application of coolant to mitigate temperature rise. With the rate and location of coolant deposition being primarily empirical, the current process brings potential risks to patients. In this study, a novel grinding device capable of continuously monitoring grinding temperatures and applying coolant precisely when needed is designed. Utilizing additive manufacturing techniques, a customized grinding tool head equipped with embedded temperature sensors and coolant channels is successfully created. This innovation has enabled the development of an intelligent closed‐loop device that provides precise temperature control during surgery. The device effectively maintains the grinding surface temperature within the user‐defined range, with a latency of less than 1 s. Furthermore, the design ensures that the coolant spray outlets remain unobstructed by debris during grinding and effectively removes debris at the interface, reducing the risk of potential complications, such as bone hyperplasia.

Processes Occurring in a Coolant Spray Cone

Processes Occurring in a Coolant Spray Cone

Temperature changes of CoolSticks during simulated use

IntroductionCold sensation is often used to check neuraxial anaesthesia and analgesia. One opportunity to reduce the carbon footprint of anaesthesia is to replace vapo-coolant sprays such as ethyl chloride with a reusable device called the CoolStick, which is cooled in a refrigerator between uses. We designed a study to investigate how long the CoolStick remains at its working temperature, which we defined as <15 °C. MethodExperiments were undertaken using a thermocouple and digital temperature sensor attached to the CoolStick. We conducted two experiments to assess temperature changes following removal from the refrigerator for 10 min; the first investigated passive re-warming in the ambient theatre environment and the second investigated re-warming in simulated use. In our third experiment, we investigated the time taken to cool the device in the refrigerator, following use. Each experiment was repeated three times. ResultsIn the passive re-warming experiment, the mean CoolStick temperature was 7.3 °C at the start, and 14.3 °C after 10 min. In the simulated use experiment, the mean CoolStick temperature was 7.3 °C at the start, and 18.9 °C at 10 min. In the cooling experiment, the mean CoolStick temperature was 15 °C at the start and 7.6 °C at 40 min. ConclusionOur study indicates that it is feasible to use the CoolStick for providing cold sensation in clinical practice. Further study would be required to directly compare the effectiveness of the device to existing methods such as coolant sprays or ice in the clinical setting.

Comments on “Effect of coolant spray on rib fracture pain of geriatric blunt thoracic trauma patients: a randomized controlled trial”

Comments on “Effect of coolant spray on rib fracture pain of geriatric blunt thoracic trauma patients: a randomized controlled trial”

Evaluation of the efficiency of an ultrasonic atomization-based coolant (uACF) spray system in external turning using different nozzle tips

Recently, the atomization-based coolant (ACF) spray system has shown promising cooling and lubrication effects in machining, but its effectiveness on machining processes has not yet been adequately studied. This paper proposes a new compact system which is developed based on the ultrasonic atomization of metalworking fluid used in machining and called the Ultrasonic Atomization-based Cutting Fluid (uACF) spray system. This study aims that, on turning AISI 1050 plain carbon steel, the effectiveness of the uACF spray system made with simple, economical, and accessible equipment is evaluated by comparing it with different cooling conditions. In this study, three different nozzle outlet tips called long wide nozzle (LWN), long narrow nozzle (LNN), and flat wide nozzle (FWN) have been used in the uACF system. Several experiments have been conducted to study the effects of the nozzle outlet tips on performance characteristics such as the main cutting force (Fc), cutting temperature (Tc), average surface roughness (Ra), and chip compression ratio (ζ). In addition, similar tests were also made for dry (DRY), compressed air (AIR), and dense coolant spraying (SPR) conditions and the test results were compared with each other. It was determined that there were statistically significant differences between the conditions of the uACF system and other classical cooling conditions. The uACF system created significant differences, especially in Fc and Tc. It was determined that the use of FWN in the uACF system was more effective than SPR on Fc, and was as effective as SPR on Tc. While the fluid consumption rate of FWN in the uACF system is 1.5 ml/min, the SPR has a fluid consumption of 20 ml/min. It has been found that the uACF spray system with a lower fluid consumption outperforms other cooling conditions, thus further enhancing the performance of the environmentally friendly production process. The effectiveness and potential of the uACF spray system on machining processes possess high efficiency and cost-effective benefits to substitute the traditional cooling-lubrication applications. The results obtained from this study have the potential to be helpful to other researchers for a similar type of study and a guide for further research on the development of different cooling systems.

Effects of subcutaneous injectıon after coolant spray on pain, hematoma, and ecchymosıs in three different regions.

This study determined the effect of subcutaneous (SC) low molecular weight heparin (LMWH) injection in three different areas (abdomen, leg, and upper arm) after coolant spray application on pain, hematoma, and ecchymosis formation. The sample of this randomized controlled study consisted of 50 patients that were administered SC LMWH once a day. The SC injection occurred after applying coolant spray to the arm, leg, or abdominal region. The study determined that there was no statistically significant difference in pain severity, hematoma, and ecchymoses between the regions of SC injection after coolant spray was applied (p > 0.05). However, the highest average pain intensity directly and 15 min after the SC injection was in the leg region. SC injection after coolant spray application in three different regions led to the biggest hematoma in the abdominal region, the biggest ecchymosis in the arm region, and the lowest pain severity in the abdominal and arm regions.

Evaluation of the Effect of Various Antioxidants on the Shear Bond Strength of the Composite Resin to the Bleached Enamel: An In Vitro study

Abstract Objective Various intrinsic and extrinsic stains cause discolored teeth, which is of great concern to patients, which can be treated by bleaching, enamel microabrasion, veneers, and crowns. However, bleaching leads to reduced bond strength if adhesive restorations are performed immediately.Thus, the application of antioxidant agents after bleaching has been recommended, which are proved to act as free radical scavengers, improving the bond strength. Materials and Methods A total of 120 extracted human maxillary incisor teeth were taken. Using a slow-speed diamond saw and a water coolant spray, the roots of all the teeth were removed approximately 2 mm below the cementoenamel junction. With the labial surface facing upward, each sectioned sample was embedded in the acrylic resin. Then, the central portion of the embedded tooth was ground flattened with 600-grit silicon carbide paper such that the labial enamel surface becomes smooth and evenly flat.All 120 samples were divided into two control groups (n = 20), i.e., positive control group (n = 10) and negative control group (n = 10) and five experimental groups (n = 100), such that each experimental group had 20 samples.The enamel surface in both the control groups and groups treated with antioxidants was thoroughly rinsed off with distilled water for 30 seconds and subjected to bonding procedure. Result Significant differences were observed among the experimental groups (p &lt; 0.05). The samples that were treated with 10% sodium ascorbate (group III) demonstrated significantly higher mean shear bond strength than the other experimental groups (p &lt; 0.05).

Effect of spray air settings of speed-increasing contra-angle handpieces on intrapulpal temperatures, drilling times, and coolant spray pattern

ObjectivesDecreasing aerosol leaks are of great interest, especially in the recent era of COVID-19. The aim was to investigate intrapulpal heat development, coolant spray patterns, and the preparation efficiency of speed-increasing contra-angle handpieces with the spray air on (mist) or off (water jet) settings during restorative cavity preparations.MethodsStandard-sized cavities were prepared in 80 extracted intact human molar teeth using diamond cylindrical drills with a 1:5 speed-increasing contra-angle handpiece. A custom-made device maintained the standardized lateral drilling force (3 N) and predetermined depth. Temperatures were measured using intrapulpal thermocouple probes. The four experimental groups were as follows: mist cooling mode at 15 mL/min (AIR15), water jet cooling mode at 15 mL/min (JET15), mist cooling mode at 30 mL/min (AIR30), and water jet cooling mode at 30 mL/min (JET30). The coolant spray pattern was captured using macro-photo imaging.ResultsThe JET15 group had the highest increase in temperature (ΔT = 6.02 °C), while JET30 (ΔT = 2.24 °C; p < 0.001), AIR15 (ΔT = 3.34 °C; p = 0.042), and AIR30 (ΔT = 2.95 °C; p = 0.003) had significantly lower increases in temperature. Fine mist aerosol was formed in the AIR15 and AIR30 preparations but not in the JET15 and JET30 preparations (p < 0.001). The irrigation mode had no influence on the preparation time (p = 0.672).ConclusionsWater jet irrigation using coolant at 30 mL/min appeared to be the optimal mode. Considering the safe intrapulpal temperatures and the absence of fine mist aerosols, this mode can be recommended for restorative cavity preparations.Clinical significanceTo increase infection control in dental practices, the water jet irrigation mode of speed-increasing handpieces with coolant flow rates of 30 mL/min should be considered for restorative cavity preparations.

Comparison of effectiveness coolant spray and placebo in patients with acute ankle trauma prospective randomized controlled trial

IntroductionCoolant spray application in musculoskeletal injuries is an effective and harmless method to treat pain and reduce functional limitation. This study assessed the clinical value of coolant spray application on patient comfort before and during the radiographic imaging process along with its early analgesic and anti-edema effects. MethodsA total of 155 patients, admitted to the emergency department between April 1, 2019, and June 31, 2019, were included in this study. The patients were randomly assigned to either a coolant spray or a saline spray (placebo) group. To the coolant spray group patients, Cryos ®Spray (Phyto Performance, Italy) was applied. To the placebo group patients, a normal saline solution in a bottle covered with white opaque paper and refrigerated at 4 °C was sprayed. Radiographic images of the patients were scored for appropriateness of the standard imaging characteristics. ResultsThe mean scores were 8.13 ± 1.8 and 6.58 ± 2.2 for the coolant spray and normal saline spray groups, respectively; the differences were statistically significant between the two groups (mean difference: -1.56, 95% CI:-2.20 to −0.92; p = .000). Patients with fractures on their radiographs and treated with coolant spray received higher scores than similar patients treated with normal saline spray (mean difference:-1.92, 95% CI:-3.28 to −0.55; p = .009). The proportion of patients requesting analgesic treatment before discharge was statistically lower in the coolant spray group compared to the normal saline group (p = .025). ConclusionsThe radiographic images taken after coolant spray intervention in patients with acute ankle trauma were more successful in showing the target structures.

Scanning electron microscopic evaluation of root surface morphology after root planing with curettes and ultrasonic perio mini-tip: An in vitro study

Mechanical removal of plaque and calculus along with bacterial toxins from the root surface by root planing is an effective means of altering the etiology of inflammatory periodontal disease which can be achieved by manual instruments (curettes) as well as ultrasonics. Curettes routinely leave a smear layer, remove more amount of root substance and take a longer time to achieve the desired root surface smoothness. On the other hand, ultrasonic instruments are easy to use, cause less operator fatigue and provide simultaneous flushing by the coolant spray. However, their only drawbacks include bulky working tips, risk of gouging the root surface if not used properly and poor tactile sensation. But the problem of bulky working tips have been overcome to a great extent by the introduction of micro-ultrasonic tips and slimline inserts, specially designed for root debridement purposes. Through this study, an attempt has been made to compare and evaluate the micro-topography of the root surface under scanning electron microscope, following instrumentation with curettes as well as ultrasonic perio mini-tip. Keywords: Root planing, Curettes, Ultrasonic perio mini-tip, Scanning electron microscope.

Effect of different stripping techniques on pulpal temperature: in vitro study.

ABSTRACTIntroduction: Proximal stripping of enamel is a routine clinical procedure employed in orthodontics to create space or for balancing tooth size discrepancies. This procedure may result in heat transfer to the pulp, predisposing it to histopathological changes and necrosis of the pulp tissue.Objective: To measure the temperature changes in the pulp chamber during different stripping procedures. Methods: 80 proximal surfaces of 40 extracted human premolar teeth were stripped using four techniques: diamond burs in air-rotor handpiece with air-water spray; diamond burs in micromotor handpiece, with and without a coolant spray; and hand-held diamond strips. A J-type thermocouple connected to a digital thermometer was inserted into the pulp chamber for evaluation of temperature during the stripping procedure. Results: An increase in the pulpal temperature was observed for all stripping method. Diamond burs in micromotor handpiece without coolant resulted in the higher increase in temperature (3.5oC), followed by hand-held diamond strips (2.8oC), diamond burs in air-rotor with air-water spray (1.9oC); and the smallest increase was seen with diamond burs in micromotor handpiece with coolant (1.65oC). None of the techniques resulted in temperature increase above the critical level of 5.5oC. Conclusion: Frictional heat produced with different stripping techniques results in increase in the pulpal temperature, therefore, caution is advised during this procedure. A coolant spray can limit the increase in temperature of the pulp.

Machining in high pressure coolant environment – a strategy to improve machining performance: a review

Machining is a commonly preferred production process. Machining with high pressure coolant, cryogenic coolant, or atomised coolant spray are the latest techniques investigated by the researchers to improve the productivity. Researchers have performed the work on various aspects of machining using high pressure coolant. Researchers have investigated effect of coolant related parameters, machining parameters, tool related parameters on surface finish, dimensional accuracy, tool wear, tool life, forces, chip morphology, tool and work piece temperature, and wear mechanism during machining of different materials. Researchers have performed the research with regard to coolant type, coolant pressure, flow rate, coolant concentration, and coolant jet direction and come up with interesting and beneficial findings. This paper presents a comprehensive literature review on high pressure coolant strategy in machining of materials with respect to various aspects. The paper presents important findings in this area and pinpoints the issues which should be investigated in future.

Machining in high pressure coolant environment – a strategy to improve machining performance: a review

Machining is a commonly preferred production process. Machining with high pressure coolant, cryogenic coolant, or atomised coolant spray are the latest techniques investigated by the researchers to improve the productivity. Researchers have performed the work on various aspects of machining using high pressure coolant. Researchers have investigated effect of coolant related parameters, machining parameters, tool related parameters on surface finish, dimensional accuracy, tool wear, tool life, forces, chip morphology, tool and work piece temperature, and wear mechanism during machining of different materials. Researchers have performed the research with regard to coolant type, coolant pressure, flow rate, coolant concentration, and coolant jet direction and come up with interesting and beneficial findings. This paper presents a comprehensive literature review on high pressure coolant strategy in machining of materials with respect to various aspects. The paper presents important findings in this area and pinpoints the issues which should be investigated in future.

The effect of oxide layer in case of novel coolant spray at very high initial surface temperature

ABSTRACT The significant reduction of Leidenfrost effect during the cooling of high carbon steel plate by different potential cooling methodologies does not assure their successful implementation in the fast quenching of high carbon steel plate due to the formation of oxide layer of comparatively low thermal conductivity on the quenching surface. Therefore, the role of oxide layer in case of different potential cooling methodologies needs to be addressed. In the present study, the effect of oxide layer on heat transfer rate in case of upward, downward, and both upward and downward facing spray with additives has been investigated by conducting and comparing the heat transfer cooling data of an AISI 1020 plate with the AISI 304 plate. The comparison clearly depicts that the formation of oxide layer during cooling significantly hinders the heat transfer rate in nucleate boiling regime; however, the reverse phenomenon is observed in transition boiling regime. Among all the coolants, the least effect of oxide layer on enhancement is obtained in case of NaCl (0.4 M)-added water spray due to the deposition of salt on the evaporating surface. The X-ray diffraction analysis and the thickness of the formed oxide layer clearly assert that the coolant depicting minimum oxidation characteristic is preferred. Abbreviations: AISI: American iron and steel institute; OES: Optical emission spectrophotometer; CHF: Critical heat flux, MW/m2; IHF: Initial heat flux, MW/m2; T CHF: Temperature at which CHF is achieved, °C; Fps: Frames per second; XRD: X-Ray diffraction; k1: Thermal conductivity of steel plate, W/m °C; k2: Thermal conductivity of oxide layer, W/m °C; k3: Thermal conductivity of coolant, W/m °C; X: x-axis, mm; Y: y-axis, mm; Z: z-axis, mm

Control of Spray Evaporative Cooling in Automotive Internal Combustion Engines

A novel approach is proposed for precise control of two-phase spray evaporative cooling for thermal management of road vehicle internal combustion (IC) engines. A reduced-order plant model is first constructed by combining published spray evaporative cooling correlations with approximate governing heat transfer equations appropriate for IC engine thermal management. Control requirements are specified to allow several objectives to be met simultaneously under different load conditions. A control system is proposed and modeled in abstract form to achieve spray evaporative cooling of a gasoline engine, with simplifying assumptions made about the characteristics of the coolant pump, spray nozzle, and condenser. The system effectiveness is tested by simulation to establish its ability to meet key requirements, particularly concerned with precision control during transients resulting from rapid engine load variation. The results confirm the robustness of the proposed control strategy in accurately tracking a specified temperature profile at various constant load conditions, and also in the presence of realistic transient load variation.

Improvement of STS316L Milling Characteristics According to Coolant Spray Position

Improvement of STS316L Milling Characteristics According to Coolant Spray Position

Analytical Model to Predict Sauter Mean Diameter in Air Assisted Atomizers for MQL in Machining Application

The threat posed by coolants to environment and worker health, escalating manufacturing costs due to coolant usage and stringent regulations enforced by the government for coolant waste disposal trigger research in unconventional coolant delivery techniques. Minimum Quantity Lubrication (MQL) is a technique delivering very small amount of coolant in the form of spray droplets that easily penetrate the tool-work piece interface for improving the cutting action, augmenting tool life and work piece quality. The droplet size which plays an import role in removing the heat and provide a lubrication action in the contact zone is controlled by the spray parameters. In this paper, an analytical model has been developed to determine the Sauter Mean Diameter (SMD) of coolant spray in MQL applied to machining processes, as a function of the spray parameters such as air pressure, viscosity of air, coolant flow rate, surface tension and density of coolant oil, based on the first principles and the conservation methods. The model developed has been validated with the experimental results and it has correlated well with reasonable accuracy.

Microstructural and thermo-mechanical analysis of quench cracking during the production of bainitic–martensitic railway wheels

Quench cracking during the production of newly developed low carbon bainitic–martensitic (LCBM) rail wheels was investigated using a microstructural and thermo-mechanical Finite Element (FE) model. The stresses associated with quench cracking during martensite phase transformation were predicted under various quenching conditions for two different grades of LCBM steels with different kinetics of martensite phase transformation. The FE analyses showed that the likelihood of quench cracking can be reduced by using a low coolant spray intensity since the internal stresses generated during the martensitic phase transformation were found to be below the steel’s flow stress. The internal stresses were predicted to be even lower with a low carbon grade LCBM steel. The microstructural and thermo-mechanical model has been used to determine favourable quenching conditions that have the potential to reduce the propensity of quench cracking during the production of LCBM railway wheels.

Prediction of residual stresses in low carbon bainitic–martensitic railway wheels using heat transfer coefficients derived from quenching experiments

Low carbon bainitic–martensitic (LCBM) steels have been recently developed for railway wheels and have been shown to provide superior properties compared to conventional pearlitic railway wheel steel grades. Pearlitic railway wheels are generally quenched at the tread region to promote the formation of compressive residual stresses in the rim to mitigate the initiation and propagation of cracks due to fatigue. However, this conventional quenching method has been shown to be unsuitable for LCBM railway wheels. Alternative quenching methods were evaluated using a FE model to develop a successful quenching process to produce LCBM railway wheels. Heat transfer coefficients were determined by employing a full scale experimental rig and were used in the FE model to model various coolant spray intensities and configurations. The FE model was used to determine optimal quenching conditions that impart compressive residual stresses to the rim of the LCBM railway wheel and the prediction of residual stresses were verified experimentally.

Cellular hotspot-type structure of the combustion wave of perchlorate ammonium

The non-one-dimensionality of the combustion wave of ammonium perchlorate was studied. An analysis of the surface of samples quenched by pressure drop and by coolant spray injection onto the burning surface, as well as extinction of samples with a diameter close to the quenching diameter, showed that, at pressures providing steady burning (2.5–7.0 MPa), the burning surface is nonplanar and nonuniform, but features a cellular hotspot-type pattern. Hotspots emerge and disappear at the burning surface, with their diameter and depth being pressure-dependent. The maximum diameter of hotspots depends on the pressure. It exceeds the characteristic thickness of the heat conduction zone by about two orders of magnitude but is smaller than the critical quenching diameter approximately twofold. Measurements of the electric conductivity of the surface layer and of the local luminosity of the flame revealed the existence of pulsations of approximately the same frequency. The period of these pulsations is close to the lifetime of hotspots. It was demonstrated that extinction curves for ammonium perchlorate obtained using pressure differ from the analogous curves for nitroglycerine-based propellants.