Chiller is widely used, one of which is the cooling of the mold, basically most mold manufacturers are indispensable chiller this equipment, so today I am here to introduce in detail to you in the mold production how to choose a suitable chiller, chiller purchase, chiller matching. Water chiller manufacturer Hangzhou Shuntian Machinery specializes in the production of industrial water chillers, water-cooled chillers, air-cooled chillers, screw chillers, in addition to injection molding machine often used with water chillers, so it is inevitable to introduce here. 1. How to choose a chiller. In fact, a mold is a heat exchanger. Heat is transferred from melted plastic to the mold, and then from the mold to the circulating cooling medium-ice water. Only a small part of the heat is transferred into the air and the pressure mold of the injection molding machine. It is well known that a considerable part of the plastic molding cycle is used for cooling, sometimes accounting for more than 80% of the plastic molding cycle, so it is absolutely necessary to minimize the cooling time. For example, a mold forming cycle usually takes 20 seconds. If the water from the original cooling tower is cooled with ice water from the chiller, it can be shortened to 16 seconds. Although the initial selection of chillers is more expensive, it can increase production by 20%, and in long-term production, it can achieve great benefits. So how do we choose the energy of ice water? From the above we can see that it is related to the specific heat capacity of the molding material, the melting temperature, the weight of the product and the temperature when the mold is taken off. In general, when the injection mold is cooled and the pressure of ice water is 0.1-0.2 Mpa, the requirement can be met. The microcomputer full-function water cooler meets the requirement. When the pressure requirement is higher than 0.2 Mpa, it is necessary to plan separately in order to use the pump with corresponding pressure to meet the requirement of water supply of the system. The relationship between flow rate and pipe diameter: the formula for calculating the ice water energy required by a pair of dies is: q = w * c * t * s Ice water energy kcal / h; W is plastic raw material weight kg / h; C is plastic raw material specific heat kcal / kg; t is melt glue temperature and product demoulding temperature difference 65 When choosing a large value, such as air-cooled chillers, s should also be a little better. For example, a mold produces PP products, and the output per hour is about 50kg. How much is the cooling requirement? Q = 50 * 0.48 * 200 * 1.35 = 6480 (kcal / h); 6480 kcal / h cooling capacity per hour; ls203s chiller is optional. It is difficult to obtain more complete data in the process of selecting chillers. According to our previous years of planning, matching sales experience, t = 200 degrees Celsius, it is a large number of commonly used products after years of statistics after an average. If there is a hot runner on the mold, the energy of the hot runner should be added to the calculation of the cooling capacity. Generally, the hot runner is kw, and the unit should be converted to kcal / h, 1 kW = 860 kcal / h. It is generally unrealistic to supply factories with sufficient water, low temperature, and low cost without using water chillers unless the factories can be near the lake where the water temperature is relatively low; the other is to use urban deep wells to supply water to meet the needs of temperature and flow, but the cost is often too high. This method can be used for experimental devices, but for factories, this is not practical. 2. The temperature of the cooling fluid (ice water) of the ice water temperature difference mold is generally controlled by the shape of the processing materials and products, such as polystyrene thin-walled beaker, the mold requires the ice water temperature below 0, and in most other cases, the temperature of the ice water required by the mold is above 5, Hangzhou Shuntian Machine The machine chiller microcomputer full-function chiller can provide more than 5 C of ice water, low temperature intelligent temperature control chiller can meet the requirements of below 5 C and below 0 C. Temperature difference of ice water at the inlet and outlet of the die is usually set according to the requirements of the product. In many cases, the temperature difference is the best when it is 3-5 degrees Celsius, but sometimes the temperature difference is 1-2 degrees Celsius. The smaller the temperature difference, the greater the ice flow required to carry out the same heat, and the less the flow required. For example, when the temperature difference is 5 degrees, the flow rate needs 60L, and when the temperature difference is 2 degrees, the flow rate needs 150L. 3. Ice water flow A pair of mold required ice water flow directly with the mold to take away the heat and ice water into and out of the mold temperature difference. For example, to remove heat from the mold at 6480 kcal / h, what is the minimum flow rate required if the temperature difference is 3 degrees Celsius? The ice water flow rate is q=6480 (3 / 60=36) (L / min). 4. The softening of theoretical water quality of ice water is also a problem that should not be neglected in the process of using chillers. The pH value of water also needs constant observation. The optimum pH value should be equal to 7. If the pH value is greater than 7, there will be terrible corrosion. If no measures are taken, there will be fouling in the evaporator and mold, which will cause heat insulation. When the effect is serious, the energy conversion effect is reduced by 30%. Obviously, this requires consideration of softening of hard water. The most effective method is to configure an electronic hard water softener in the system, which is designed and manufactured on the basis of the principle of separation from exchange.