Frying pan device

Abstract

This utility model relates to the field of cooking equipment technology, and discloses a wok device. The wok is shaped like a cylinder with an open upper end and a closed, dome-shaped lower part. The wok has a nitrided inner wall, and a scraper that contacts the inner wall and can be used to flip food. An anti-stick coating is provided on the inner wall of the wok above the tip of the scraper to prevent food from sticking. This utility model's wok device achieves anti-stick properties through a combination of nitriding treatment and an anti-stick coating. Nitriding treatment enhances the hardness of the wok wall, improves its wear resistance, high-temperature resistance, and corrosion resistance, and extends the wok's service life.

Description

Technical Field

[0001] This utility model relates to the field of intelligent cooking equipment technology, specifically to a non-stick wok for cooking robots. Background Technology

[0002] With the development of intelligent kitchen equipment, intelligent cooking machines have been widely used due to their advantages such as automated cooking and reduced manual operation. However, when cooking ingredients containing starch and fat (such as potatoes, meat slices, and sweet potatoes), the following obvious drawbacks exist:

[0003] 1. Insufficient durability of non-stick structure: Traditional non-stick pans rely on a full-pan coating to achieve non-stick properties. However, during high-temperature cooking, the coating is easily worn down by hard ingredients such as bones, which reduces the non-stick effect, lifespan, and food safety.

[0004] 2. Sticking problem: Starchy foods tend to gelatinize when heated, and the surface protein of fatty foods (such as meat) tends to coagulate when heated. If they come into direct contact with the hot pan wall and there is no effective insulation, they are prone to sticking, which can cause the food to burn, break in shape, and affect the taste and appearance. Summary of the Invention

[0005] The technical problem to be solved by this utility model is to provide a wok device that can achieve a long-lasting and stable non-stick effect and ensure that the food is heated evenly.

[0006] To solve the above-mentioned technical problems, this utility model provides a wok device. The wok in the wok device is shaped like a cylinder with an open top and a closed surface with a spherical crown shape at the bottom. The wok has an inner wall that has been nitrided. The wok is equipped with a scraper that contacts the inner wall of the wok and can flip the food up and down. An anti-stick coating is provided on the area of ​​the inner wall of the wok above the top of the scraper to prevent the food from sticking to it.

[0007] Preferably, an electromagnetic heating coil for heating the wok is provided on the outer wall area of ​​the wok corresponding to the scraper.

[0008] Preferably, the side of the scraper that contacts the inner wall of the wok is made of Teflon material.

[0009] Preferably, the anti-stick coating is a Teflon coating, a ceramic coating, or a metal composite coating.

[0010] Preferably, the height of the anti-stick coating is in the range of one-third to two-thirds of the height from the top of the scraper to the rim of the wok.

[0011] This invention's wok device achieves anti-stick properties through a combination of "nitriding treatment + anti-stick coating." Nitriding treatment enhances the hardness of the wok wall, improving its wear resistance, high-temperature resistance, and corrosion resistance, thus extending the wok's lifespan. The anti-stick coating is applied only to the inner wall area of ​​the wok above the top of the scraper, specifically covering areas the scraper cannot reach but where food might fall, preventing food from sticking to the wok wall and becoming impossible to remove. This results in a more stable overall anti-stick effect. Furthermore, the side of the scraper that contacts the wok wall uses a flexible Teflon sheet to further reduce friction and improve elastic contact during movement. Attached Figure Description

[0012] Figure 1 This is a three-dimensional view of the wok in the wok device of this utility model;

[0013] Figure 2 This is a cross-sectional view of the wok device of this utility model;

[0014] Figure 3 This is a partially exploded view of the scraper in the wok device of this utility model;

[0015] Figure 4 This is a flowchart illustrating the cooking method of the wok device used in this utility model;

[0016] The components in the diagram are labeled as follows: 1. Wok; 2. Scraper; 21. Drive unit; 22. Main body; 23. Blind groove; 24. Scraper; 3. Anti-stick coating; 4. Electromagnetic heating coil. Detailed Implementation

[0017] The wok device of this utility model will be described in detail below with reference to specific embodiments.

[0018] I. Wok assembly

[0019] like Figure 1-3 As shown, the wok device includes a wok 1, a scraper 2, an electromagnetic heating coil 4, and an anti-stick coating 3.

[0020] 1. Wok

[0021] The wok 1 is shaped like an open cylinder at the top and a closed surface in the shape of a spherical crown at the bottom. Preferably, the diameter of the cylindrical part is in the range of 26-46cm, the radius of curvature of the spherical crown part is in the range of 13-23cm, the overall height of the wok 1 is in the range of 24-50cm, and the ratio of the height of the cylindrical part to the height of the spherical crown part is in the range of 1:1 to 2:1. The whole wok is made of wrought iron, 430 stainless steel or 443 stainless steel to ensure good thermal conductivity, magnetic conductivity and heat storage.

[0022] The wok 1 has an inner wall that has undergone nitriding treatment. The specific nitriding treatment process is as follows:

[0023] Step 1: First, treat the surface of wok 1;

[0024] Step 2: Place wok 1 into a nitriding furnace, fill it with ammonia, and heat the furnace to 500℃. At this point, the ammonia decomposes into nitrogen and hydrogen. Nitrogen atoms penetrate between the metal lattice of the inner wall of wok 1 to form a nitrided layer, thereby increasing the hardness of the inner wall of wok 1.

[0025] To further improve the wear resistance, high-temperature resistance, and corrosion resistance of the inner wall of wok 1, the following processing steps are also included:

[0026] Water vapor is introduced into the nitriding furnace, forming an oxide layer of iron oxide on top of the white brightening layer and between the metal lattice. This oxide layer forms a reliable and stable structure with the metal surface of the inner wall of the wok 1.

[0027] 2. Scraper 2

[0028] like Figure 2 As shown, a spatula 2 for stir-frying ingredients is provided in the wok 1. The spatula 2 can move relative to the wok 1 under the action of the drive component 21. The spatula 2 is spiral-shaped, with its head end located at the bottom of the wok 1 and its tail end extending backward and upward in the direction of rotation about the axis of the wok 1. The shape of the spatula 2 can also be the same as the vertical cross-sectional shape of the wok 1.

[0029] The height of the scraper 2 is preferably two-thirds of the height of the wok 1, which can effectively stir-fry the ingredients concentrated in the lower part of the wok 1 while preventing the ingredients from being turned out of the wok 1.

[0030] To ensure the rigidity of the main body 22 of the scraper 2 for stir-frying large quantities of food, the main body 22 of the scraper 2 is made of food-grade stainless steel and its surface is coated with Teflon to prevent food from sticking to the scraper 2.

[0031] like Figure 3 As shown, to avoid rigid friction between the scraper 2 and the inner wall of the wok 1, a blind groove 23 extending from the head to the tail is provided on the end face of the main body 22 facing the inner wall of the wok 1. A scraper 24 is installed in the blind groove 23 in a quick-insertion manner. The scraper 24 is an elastic element made of Teflon material with a thickness of about 1-3mm. The scraper 24 is flexibly attached to the inner wall of the wok 1. During the cooking process in the wok 1, the scraper 24 is always in close contact with the inner wall of the wok 1. While stir-frying the food, it can also scrape off the food adhering to the inner wall of the wok 1 within the corresponding height range, effectively avoiding food sticking to the wok or even burning, which would cause uneven heating of the food in the wok, as well as food safety problems caused by hard friction between the scraper 2 and the wok 1.

[0032] 3. Electromagnetic heating coil 4

[0033] An electromagnetic heating coil 4 is provided on the outer wall of the wok 1 in the area opposite to the rotating covering part of the scraper 2 to heat the wok 1. The purpose of this arrangement is as follows:

[0034] When cooking, the amount of food poured into the pot is usually within the area covered by the rotating spatula 2. If the number of turns of the heating coil is increased and the area not filled with food is covered, it will increase the material cost of the coil and lead to energy waste.

[0035] 4. Anti-stick coating 3

[0036] During the process of adding ingredients, some ingredients will inevitably fall onto the inner wall of the wok 1 above the top of the scraper 2. This area is beyond the reach of the scraper 2. To prevent the ingredients that fall into this area from sticking and becoming stuck, an anti-stick coating 3 is provided in this area. This reduces the stickiness of the ingredients that fall into this area to the wok 1, and avoids uneven mixing and the mixing of raw vegetables when the food is taken out of the wok.

[0037] The anti-stick coating 3 is a Teflon coating, a ceramic coating, or a metal composite coating, preferably a Teflon coating. The height of the anti-stick coating 3 is preferably within one-third to two-thirds of the height from the top of the scraper 2 to the rim of the wok 1. The closer it is to the rim of the wok 1, the lower the risk of food falling off. Therefore, the anti-stick coating 3 does not need to cover the entire upper area of ​​the wok 1, which can save costs.

[0038] II. Cooking methods for ingredients containing starch and fat

[0039] Based on the structure of the wok device described above, the following cooking methods can greatly improve the non-stick properties of ingredients and effectively lock in the internal moisture of the ingredients, resulting in tender and delicious dishes.

[0040] like Figure 4 As shown, the specific cooking steps are as follows:

[0041] Step 1: Before cooking, stir the starchy or fatty ingredients with a set amount of cooking oil to coat the surface of the ingredients.

[0042] If the ingredients need to be pre-treated with other seasonings, the other seasonings should be added first, and then the cooking oil should be added last, so that the cooking oil forms an oil film isolation layer on the surface of the ingredients and seasonings.

[0043] Step 2: Heat wok 1 to a temperature of no less than 120 degrees Celsius, then put the food coated with cooking oil into wok 1. The oil film layer will effectively reduce the stickiness.

[0044] Step 3: The rapidly rotating spatula 2 causes the ingredients to come into intermittent contact with the inner wall of the wok 1, causing the starch or fat in the ingredients to solidify quickly.

[0045] This cooking method uses cooking oil to form an oil film on the outer surface of the ingredients, effectively preventing them from sticking to the pan under high temperatures and locking in the moisture inside the ingredients, resulting in tender and delicious dishes.

[0046] To further improve the anti-sticking effect, in step two, the food is placed in the wok at a temperature of 200 degrees Celsius. This creates a gaseous isolation layer (containing oil vapor and a small amount of water vapor) between the oil-coated food and the high-temperature wok wall, thereby reducing the adhesion between the food and the wok.

[0047] This method utilizes the Leidenfrost effect triggered by the instantaneous contact between the hot pan wall and the cold oil to instantly form a thick gaseous barrier layer between the food coated in the cold oil and the pan wall, achieving physical non-sticking and reducing the degree of direct contact between the food and the inner wall of the wok. The rapid heating causes the protein on the surface of the meat slices to coagulate, forming a protective layer that locks in moisture. At the same time, the uniform heat conduction and lubrication of the oil temperature and oil film are utilized to ultimately achieve the effect of tender, smooth, non-stick, intact, and flavorful meat slices.

[0048] The edible oil is a high smoke point edible oil (smoke point refers to the critical temperature at which edible oil begins to smoke and decompose when heated), preferably edible oils with a smoke point of 200°C or higher, such as peanut oil, rapeseed oil, soybean oil, or corn oil.

[0049] Using cooking oil with a high smoke point results in a more stable molecular structure that is less prone to decomposition at high temperatures, making it easier to generate a vapor layer while avoiding burnt flavors and harmful substances.

[0050] The ingredients include potatoes, taro, sweet potatoes, or meat, etc. The cooking methods of this invention will be specifically described below using stir-fried shredded potatoes and stir-fried beef as examples:

[0051] 1. Stir-fried shredded potatoes

[0052] Step 1: Prepare 500g of shredded potatoes after cutting and washing, add 8g of peanut oil (1.6% of the weight of the ingredients), and stir until each shredded potato is coated with an oil film.

[0053] Step 2: Heat wok 1 until the temperature of the wok wall reaches 150℃ (monitored by the temperature detection system in the cooking robot).

[0054] Next, quickly add the potato shreds coated in peanut oil into the high-temperature wok 1. The oil film layer effectively reduces the stickiness.

[0055] Step 3: Start the scraper 2 to rotate and turn the potato shreds, so that the potato shreds come into intermittent contact with the pot wall. The heat from the pot wall is transferred to the potato shreds through the oil film, causing the surface starch to coagulate quickly within 1-2 minutes (to prevent water absorption and gelatinization); during this time, continue to turn the potato shreds with the scraper 2 to ensure that each potato shred is heated evenly.

[0056] Finally, when the potato shreds become translucent and the edges are slightly browned, add salt to taste. Continue stirring with a spatula for 30 seconds, then stop heating to complete the cooking of crispy potato shreds.

[0057] The above method uses oil to coat the starch in the potatoes, reducing the gelatinization of the starch. At the same time, under the action of cooking temperature, the starch in the potatoes is quickly solidified, making the stir-fried potato shreds crispier than those stir-fried with vinegar.

[0058] 2. Stir-fried beef

[0059] Step 1: Select 300g of beef tenderloin, cut it into 3mm thick slices, marinate with light soy sauce and cooking wine for 10 minutes, then add cornstarch to coat the beef slices; take the coated beef slices, add 5g of corn oil (1.7% of the ingredient weight), and stir until the surface of the meat slices is evenly coated with oil.

[0060] Step 2: Heat wok 1 to 200℃, then place the oil-coated beef slices into wok 1. The cold oil comes into contact with the 200℃ wok wall to create a gaseous insulating layer, preventing the meat slices from sticking directly to the bottom. At the same time, the heat from the wok wall is quickly transferred through the oil, causing the protein on the surface of the meat slices to solidify rapidly within 30 seconds, forming a protective layer that locks in the internal moisture.

[0061] Step 3: Use the spatula 2 to stir-fry the beef, so that the slices of beef intermittently contact the side of the pan. Within 2 minutes, the slices of beef will turn from pink to grayish-white (70-80% cooked). At this time, the internal moisture of the slices of beef has not been lost too much, so it will maintain a tender and smooth texture.

[0062] Finally, remove the sliced ​​meat and drain the oil. Leave a little oil in the pan and sauté the scallions and ginger until fragrant. Add the side dishes and stir-fry, then return the sliced ​​meat to the pan. Pour in the seasoning sauce and stir-fry for 1 minute until the sauce thickens.

[0063] This invention transforms the experience-based operation of "hot pan, cold oil" into controllable parameters, and combines a gaseous isolation layer (physical isolation), rapid coagulation of protein and starch (chemical protection), and intermittent contact of the scraper 2 (mechanical control) to solve the technical problems of food sticking to the pan and short service life of the coated wok 1 in existing intelligent cooking robots.

[0064] annotation:

[0065] 1. Protein denaturation and adhesion mechanisms:

[0066] The surface of meat is rich in proteins (such as actin and myosin). When meat comes into contact with a hot pan (usually above 60°C), the proteins denature rapidly, their molecular structures unfold and re-crosslink, forming a sticky substance. If the pan surface is not adequately lubricated at this time (e.g., insufficient oil or uneven coating), these denatured proteins will directly adhere to the metal pan surface, causing the meat to stick.

[0067] Key temperature points:

[0068] Protein denaturation temperature: denaturation begins at approximately 60–80°C.

[0069] Maillard reaction temperature: 140–165℃, at which point proteins and carbohydrates react to form a caramelized, crispy crust. If the temperature is insufficient, a crispy crust cannot form; instead, adhesion will be exacerbated.

[0070] 2. Balance between pot surface temperature and lubrication

[0071] Reasons for sticking in a low-temperature cooker:

[0072] If the pan is not hot enough (e.g., not preheated), the temperature will drop sharply after the meat is put into the pan, causing the moisture to evaporate slowly instead of caramelizing quickly. At this time, the sticky substance formed by protein denaturation mixes with the seeping juices to form a "glue layer" that sticks the meat to the pan.

[0073] The anti-stick mechanism of high-temperature cookware:

[0074] The indirect effect of the Leidenfrost effect: When the pan temperature is extremely high (such as above the smoke point of the oil), the oil may partially vaporize, forming a tiny layer of steam, reducing the direct contact between the meat and the pan.

[0075] 3. Excessive starch (core cause):

[0076] Potatoes contain a lot of starch. When potato shreds are heated, the starch granules absorb water and swell and gelatinize, forming a thick gel that coats the surface of the potato shreds, making them soft, sticky, and losing their crispness.

[0077] If the surface starch is not fully removed after cutting, or if too much moisture seeps out during the frying process (leading to increased starch gelatinization), the crispness will be greatly reduced.

[0078] Potatoes contain a lot of water. If the shredded potatoes are not fully drained or shaken / absorbed of surface moisture, the pan temperature will drop rapidly after they are put into the pan, resulting in them being "boiled" rather than "fried".

[0079] If the stir-frying time is too long or the heat is not high enough, the moisture inside the potato shreds will continue to seep out. This moisture will be absorbed by the starch and gelatinized, or it will directly create a "boiling" environment in the pot, making the potato shreds soft.

[0080] Adding salt too early: Salt will cause water to seep out of the potato shreds cells quickly (due to osmotic pressure), resulting in excessive water content and accelerating starch gelatinization and softening.

[0081] 4. The mechanism behind the "crispy" texture of shredded potatoes

[0082] Intact cell structure: The crispness of vegetables (including potatoes) mainly comes from the structure of their cell walls (primarily cellulose and hemicellulose) and the intercellular binding substances (such as pectin). When the cell structure remains relatively intact and the cell walls are not excessively damaged, biting into them produces a "crunch" sound, which is what makes them crisp.

[0083] Inhibiting starch gelatinization: The crispness of potatoes especially requires inhibiting excessive starch gelatinization. Gelatinized starch forms a soft and sticky texture, masking the crispness brought about by the cell wall structure.

[0084] Control moisture seepage: Minimize the seepage of moisture from the shredded potatoes. Seeping moisture not only dilutes the flavor, but more importantly, it dissolves and activates starch, promoting gelatinization. Excessive moisture also creates a "boiling" environment. Rapid high-temperature stir-frying quickly denatures the surface proteins, forming a "protective film" that locks in internal moisture to some extent.

[0085] The role of acids: An acidic environment (vinegar) helps to:

[0086] Strengthening pectin: Pectin can form a more stable gel structure under acidic conditions, which helps maintain the connection between cells and the firmness of the overall structure.

[0087] Inhibits enzyme activity: May inhibit the activity of some enzymes that cause vegetables to soften.

[0088] Delaying starch gelatinization: Acidic conditions can slow down the rate at which starch granules absorb water, swell, and gelatinize to some extent.

Claims

1. A wok apparatus, wherein the wok is shaped as a cylinder with an open upper end and a closed surface in the shape of a spherical cap at the bottom, characterized in that, The wok has a nitrided inner wall, and a scraper that contacts the inner wall and can flip the food. An anti-stick coating is provided on the inner wall of the wok above the top of the scraper to prevent food from sticking to it.

2. The wok apparatus as described in claim 1, characterized in that, An electromagnetic heating coil is provided on the outer wall area of ​​the wok corresponding to the scraper to heat the wok.

3. The fryer apparatus of claim 2, wherein, The side of the scraper that contacts the inner wall of the wok is made of Teflon.

4. The fryer apparatus of claim 3, wherein, The anti-stick coating is a Teflon coating, a ceramic coating, or a metal composite coating.

5. The fryer apparatus of claim 4, wherein, The height of the anti-stick coating is between one-third and two-thirds of the height from the top of the scraper to the rim of the wok.

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