Design Of Salting Device For Ham And Its Salting Uniformity Detection

Salt on ham is a key step in the production of ham.The amount of salt and its uniformity have a direct impact on the quality of the ham.At present,he production of domestic ham is still dominated by artificial salt,with high labor intensity and low efficiency,and it is difficult to meet the needs of mass production and standardization management.Therefore,this thesis takes square ham as the research object,and develops a ham salting device to meet the uniform and controllable demand of salt on ham,and to study the detection method of salt uniformity on ham.The main research contents of the thesis are as follows:1.According to the salt requirements of ham,a ham salting device was developed.The ham suspension conveying device was designed and built to make the ham forward and rotate in the upper salt area to ensure the uniformity of the upper salt.An ejector with an adjustable salt rate is designed and processed for salt on ham.A salt box was designed and built to block and recover salt particles to avoid contamination and waste.The control system based on PLC is designed to realize the automatic operation of the device,and the conveying line speed is adjusted by the PLSY command to achieve the purpose of adjustable salt time on the ham.2.Ejector working pressure selection and nozzle selection.Through experiments,it was determined that the working pressure of the injector was 0.3Mpa,and the jet fan angle of the nozzles and flat nozzles of different calibers under the pressure was obtained,and the relationship between the salt discharge rate and the nozzle distance was obtained.The results show that under the same caliber,the jet fan angle of the tip nozzle is smaller than that of the flat nozzle,and the salt control effect of the tip nozzle is better than that of the flat nozzle.In order to balance the jet fan angle and salt control effect,an 8mm tip nozzle was selected as the working nozzle.3.Using the three-dimensional numerical simulation technology,the injector is simulated under the designed working parameters,and the gas flow field and the distribution of salt particles in the injector are obtained.The results show that the flow velocity increases significantly to supersonic speed and forms a shock wave when flowing through the outlet of the trachea.At this time,the velocity near the inner wall surface of the injector is small,but no obvious eddy current is formed at the nozzle;the salt particle acts on its own gravity.Next,accumulation occurs at the bottom of the chamber.When the time T=5s,the accumulation of salt particles at the bottom of the chamber reaches the maximum,and then the accumulation of salt particles at the bottom of the chamber begins to decrease gradually,and reaches a relatively stable state at T=8s.The state of the film,only a thin layer of accumulation at the bottom of the chamber.Since the nozzle has a taper,the salt particles can be recirculated,preventing accumulation at the nozzle and causing clogging.4.An image acquisition system for salt particle uniformity detection on ham surface was designed.Through comparison and calculation,the models of industrial cameras and lenses were determined.In order to highlight the salt particle distribution information on the surface of the ham,a blue LED strip light source was selected,and the image was collected by a low angle lighting method.The light box is designed with a length,width and height of 400 ?200 ?510 mm.Image acquisition software based on camera SDK is written in Visual Studio 2013.5.A method for detecting salt uniformity on ham based on machine vision was studied.First,the salt particles are assumed to be salt and pepper noise,and the salt particle region is obtained by median filtering and image subtraction.Then,the image is divided into 16 rectangular small blocks,and the gray mean value of each regional small block is selected as the characteristic parameter composition data set for statistical analysis,and the uniformity of the upper salt is determined by the standard deviation of the data set.Finally,the uniformity test was performed using the upper salt device.The results showed that the standard deviations of the five groups of gray mean values were 1.39,1.41,1.69,1.33,1.43 respectively,and there was no significant difference(p=0.843>0.05),which proved that the designed ham salt device can achieve uniform salt.